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Wyszukujesz frazę "Simulation analysis" wg kryterium: Temat


Tytuł:
Probabilistic assessment of the short-circuit duration on the 220 kV transmission line basing on simulation analysis
Autorzy:
Frąckowiak, R.
Piechocki, P.
Powiązania:
https://bibliotekanauki.pl/articles/97379.pdf
Data publikacji:
2012
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
transmission lines
current
simulation analysis
Opis:
In the paper, the problem of defining the short circuit duration time for the short-circuit effect calculations, especially thermal and electromagnetic ones, has been discussed. In author’s opinion, the results of probabilistic research could be helpful when resolving the problem. Therefore, a tailored simulation model based on the analysis of the protections and circuit breakers operation during the transmission lines fault clearance has been developed. Due to the results of simulation study, the found values of the fault duration time could be related to the expected risk of their exceeding depending on both the protection system configuration and the type of the circuit breakers applied.
Źródło:
Computer Applications in Electrical Engineering; 2012, 10; 275-282
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation Analysis of the Effects of Increased Foreign Ownership on Wage Inequality
Autorzy:
Zulfiu Alili, Merita
Powiązania:
https://bibliotekanauki.pl/articles/1036337.pdf
Data publikacji:
2014
Wydawca:
Academicus. International Scientific Journal publishing house
Tematy:
simulation analysis
foreign ownership
wage inequality
Opis:
Transition countries have, in general, experienced an increase in labour market inequality during and after the initial transition period. Theory and empirical studies analysing the causes and mechanisms of increasing inequality in transition economies identify globalisation, skilled-biased technological change, differences in access to schooling, the pattern and level of unemployment and institutions as important factors. Foreign direct investment (FDI) has increased significantly in transition economies during the transition period and has been considered to be an important channel for the diffusion of new technology, managerial skills and new knowledge. As a result of technological and management expertise FDI may raise the level of wages in the host economies, improve working conditions and increase employment, though little previous research has focused on these effects in transition economies. Using the GINI coefficient as the measure of wage inequality a simulation analysis indicates that the net effects of FDI on wage inequality will depend in part on country specific factors, namely how large are the differences in skilled and unskilled wages, the skill-intensity of employment in foreign-owned firms compared to domestic ones and the relative size of the foreign-owned sector.
Źródło:
Academicus International Scientific Journal; 2014, 09; 140-158
2079-3715
2309-1088
Pojawia się w:
Academicus International Scientific Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compensation of springback deformation in sheet metal forming analysis
Autorzy:
Świątoniowski, A.
Bałon, P.
Powiązania:
https://bibliotekanauki.pl/articles/246833.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
springback
compensation
optimization
simulation analysis
metal forming
Opis:
Process of metal forming in automotive parts construction becomes more and more demanding due to tightened up tolerance and trials to realize very complex and in many cases unworkable design in mass production. Moreover, it is required to cut and limit costs of die production and simultaneously keep high quality. Furthermore, construction elements are more often produced from materials which belong to High Strength Steel or Ultra High Strength Steel. Application of this kind of materials considerably reduces construction mass due to high durability. Nevertheless, it results in appearance of springback effect. Springback value depends mainly on used material as well as part geometry and in extreme cases deviation value from target part might reach in some areas high level. Designing of dies requires using of appropriate Finite Element Method software to make them more economic and less timeconsuming. Therefore, analysis of forming process alone is not enough to be taken into account. During the design process, it is needed to include the die compensation to reach optimized blank sheet. Prediction of springback effect by tryout method and then correction of deviation is difficult arduous and painstaking. Virtual compensation methods make it possible to receive precise result in a short time. This way gives a huge economic advantage eliminating useless milling and allows producing of die just in time. Optimization process can relate to individual operation as well as take into consideration intermediate stages in the final result, at the same time increasing the accuracy. Die compensation with software application was experimentally verified by prototype die.
Źródło:
Journal of KONES; 2012, 19, 3; 459-468
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation analysis of safe passing between ships on the seaway Szczecin–Świnoujście with the applicable port regulations
Autorzy:
Sokołowska, S.
Marcjan, K.
Gralak, R.
Powiązania:
https://bibliotekanauki.pl/articles/358986.pdf
Data publikacji:
2013
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
simulation analysis
safe passage
seaway
restricted section
port regulations
Opis:
This paper presents simulation analysis of vessels approaching and vessels departuring from the port of Szczecin and Police focusing on the encounters between two vessels. The analysis parameters such as length and draft were examined. Particular attention was paid to the restricted sections of the seaway between Zalew Szczeciński and Basen Górniczy. The results of these simulation trials and the resulting analysis can be helpful while updating port regulations and for the assessment of the traffic density and the capacity of the waterway.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2013, 36 (108) z. 2; 175-181
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ potencjalnych zmian składników popytu finalnego na gospodarkę Polski. Analiza na podstawie modelu WM-1
Changes in Final Demand Components and Their Potential Impact on the Polish Economy: An Analysis Based on the WM-1 Model
Autorzy:
Welfe, Aleksander
Karp, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/574493.pdf
Data publikacji:
2018-12-20
Wydawca:
Szkoła Główna Handlowa w Warszawie. Kolegium Analiz Ekonomicznych
Tematy:
analizy symulacyjne
makromodele
modelowanie ekonometryczne
simulation analysis
macromodels
econometric modelling
Opis:
The WM-1 model is a unique macromodel that uses monthly data to describe the functioning of the Polish economy. This article presents the results of a stochastic simulation obtained with the model that demonstrates the potential impacts on the Polish economy of: (1) increasing/decreasing exports, (2) increasing/decreasing investment outlays, and (3) increasing household incomes. The simulation shows that various sources of shocks induce different responses from the economy, both in terms of their strength and the speed of adjustment. There are also distinct asymmetry effects in the reactions of economic entities. The Polish economy has been shown to be more vulnerable to negative shocks decelerating economic activity than to shocks stimulating economic growth.
Makroekonometryczny model WM-1 jest pierwszym makromodelem opisującym funkcjonowanie gospodarki Polski opartym na danych miesięcznych. Przedstawione w artykule rezultaty symulacji stochastycznych otrzymane na modelu WM-1 ilustrują potencjalne skutki dla gospodarki Polski jakie wywarłby (1) wzrost/spadek eksportu, (2) wzrost/spadek nakładów inwestycyjnych lub (3) wzrost dochodów gospodarstw domowych. Uzyskane wyniki pokazują, że w zależności od źródła zaburzenia reakcje gospodarki są różne, i to zarówno pod względem siły, jak i szybkości dostosowań. Wyraźne są również efekty asymetryczności w reakcjach podmiotów gospodarczych. Gospodarka Polski okazuje się być bardziej wrażliwa na impulsy o charakterze negatywnym, które prowadzą do spadku aktywności gospodarczej, niż na impulsy prowzrostowe.
Źródło:
Gospodarka Narodowa. The Polish Journal of Economics; 2018, 296, 4; 35-50
2300-5238
Pojawia się w:
Gospodarka Narodowa. The Polish Journal of Economics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vibration control using a modern control system for hybrid composite flexible robot manipulator Arm
Autorzy:
Ramalingam, S.
Mohideen, S. Rasool
Powiązania:
https://bibliotekanauki.pl/articles/27314189.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
composite material
Al6082 alloy
simulation analysis
vibration amplitude
LQR controller
Opis:
In this research, a model of a robotic manipulator flexible structure and an equation of motion for controller design is planned. The structural material chosen for the robot structure was a hybrid composite. A comparison study was carried out for the aluminium 6082 alloy for the flexible manipulator arm application. Vibration behavior and control implementation was analyzed by adding joint flexibility in the system. Using a simulation algorithm, the system parameter calculation is carried out through MATLAB software for vibration amplitude, transient period, steady-state error, and settling time of flexible robotic arm system. In a systematized motion equation, flexible robotic deflections are organized via the assumed mode (AM) and Lagrange techniques (LT). The graph analysis of hybrid composite and AL6082 materials with high stiffness coefficients is plotted. These obtained values from the plot are utilized for Linear Quadratic Regulator (LQR) controller design. The LQR output facts for both aluminium structural robotic arm and composite material robotic arms are established.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2022, 16, 2; 36--45
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza symulacyjna sieci IEEE 802.11e o topologii gwiazdy w przypadku występowania stacji ukrytych
A simulation analysis of star topology IEEE 802.11e networks in the presence of hidden nodes
Autorzy:
Kosek, K.
Natkaniec, M.
Pach, A.R.
Powiązania:
https://bibliotekanauki.pl/articles/298560.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
IEEE 802.11
stacja ukryta
analiza symulacyjna
hidden nodes
simulation analysis
Opis:
W artykule przedstawiono wyniki analizy symulacyjnej sieci IEEE 802.11e ze stacjami ukrytymi. W celu oceny wpływu stacji ukrytych na pracę i wydajność sieci bez infrastruktury, badania przeprowadzono dla dwóch sieci. Jednej o topologii trójwęzłowej i drugiej o topologii czterowęzłowej gwiazdy. Dodatkowo wykazano niezdolność trybu EDCA dostępu do kanału radiowego do zapewnienia wymaganej jakości usług, w tym przede wszystkim głosowych i wideo. Ponadto zweryfikowano użyteczność mechanizmu RTS/CTS w zmniejszaniu wpływu stacji ukrytych na wydajność badanych sieci.
The article presents results derived from a simulation analysis of IEEE 802.11e networks in the presence of hidden nodes. In order to show how meaningful the degrading impact of hidden nodes on ad-hoc networks performance is, two different star topologies were analyzed. There were three- and four-node ones. Additionally, in the presence of hidden nodes, the inability of the EDCA mechanism to assure a desired quality of service for different services (most of all video and voice) was shown. Furthermore, the usefulness of the RTS/CTS mechanism was also verified.
Źródło:
Telekomunikacja Cyfrowa : technologie i usługi; 2008-2009, 9; 35-45
1505-9405
Pojawia się w:
Telekomunikacja Cyfrowa : technologie i usługi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza ruchowa pojazdów szynowych z uwzględnieniem zmian napięcia na odbieraku prądu
Analysis of rail vehicle motion including an influence of varying voltage on the current collector
Autorzy:
Jarzębowicz, L.
Judek, S.
Powiązania:
https://bibliotekanauki.pl/articles/266327.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Elektrotechniki i Automatyki
Tematy:
trakcja elektryczna
zasilanie trakcyjne
obliczenia symulacyjne
Simulink
electric traction
traction supply
simulation analysis
Opis:
W artykule zaproponowano metodykę wykonywania analizy ruchowej pojazdów szynowych, która uwzględnia wpływ zmieniającego się napięcia zasilającego pojazd na jego właściwości ruchowe. Wykorzystując model opracowany w programie Simulink wskazano na istotne różnice w czasie przejazdu oraz w wartościach napięcia zasilającego pomiędzy proponowanym sposobem analizy a powszechnie stosowanym podejściem uproszczonym.
The paper proposes a novel approach to analyze a rail vehicle motion, which includes an impact of varying voltage at the current collector on the vehicle’s dynamics. According to present standards, vehicle’s maximal power has to be limited and the value of this limit depends on actual value of vehicle’s supplying voltage. This, in turn, affects vehicle tractive effort and its current consumption. A model reflecting vehicle dynamics as well as its supply parameters was designed in Simulink. By a case study, it was proven that neglecting the impact of vehicle varying supply voltage on vehicle dynamics leads to substantial errors in reflecting both vehicle motion and its supply-related parameters.
Źródło:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2017, 57; 29-32
1425-5766
2353-1290
Pojawia się w:
Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Springback Compensation in Cold Forming Process for High Strength Steel
Kompensacja sprężynowania w procesie formowania stali na zimno
Autorzy:
Bałon, P.
Świątoniowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/352130.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
springback
compensation
optimization
simulation analysis
metal forming
sprężynowanie
kompensacja
optymalizacja
analiza symulacji
formowanie metali
Opis:
Process of metal forming in automotive parts construction becomes more and more demanding due to tightened up tolerance and trials to realize very complex and in many cases unworkable design in mass production. Moreover it is required to cut and limit costs of die production and simultaneously keep high quality. Furthermore, construction elements are more often produced from materials which belong to High Strength Steel or Ultra High Strength Steel. Application of this kind of materials considerably reduces construction mass due to high durability. Nevertheless, it results in appearance of springback effect. Springback value depends mainly on used material as well as part geometry and in extreme cases deviation value from target part might reach in some areas high level. Reduction of implementation time, development of metal components and greater restrictions about designing and producing stamping tools generate extra costs. Designing of dies requires using of appropriate Finite Element Method software to make them more economic and less time-consuming. Therefore analysis of forming process alone is not enough to be taken into account. During the design process it is needed to include the die compensation to reach optimized blank sheet. Prediction of springback effect by tryout method and then correction of deviation is difficult arduous and painstaking. Virtual compensation methods make it possible to receive precise result in a short time. This way gives a huge economic advantage eliminating useless milling and allows to produce of die just in time. Optimization process can relate to individual operation as well as take into consideration intermediate stages in the final result, at the same time increasing the accuracy. Die compensation with software application was experimentally verified by prototype die. Quality requirements regarding products of sheet stamping process are very high due to the technologies of automatic assembly of formed components. Springback, as the main source of drawpieces inaccuracy, is the function of material data, shape of tools and process parameters. Therefore, springback deformation becomes critical problem especially for AHSS steel when the geometry is complex. Hence, it is necessary not only to find springback effect value but also include it during early stage of designing by tooling designers.
Proces przeróbki metalu w produkcji elementów konstrukcji samochodów staje się coraz bardziej wymagający ze względu na zaostrzenie tolerancji oraz próby urzeczywistnienia bardzo złożonego kształtu w produkcji masowej. Do tego należy dodać ograniczenia i cięcia kosztów narzędzi formujących. Coraz częściej elementy konstrukcyjne wytwarzane są z materiałów należących do grupy Ultra High Strength Steel. Zastosowanie tego typu materiałów znacznie obniża masę konstrukcji ze względu na dużą wytrzymałość, jednak kosztem dużego wpływu na sprężynowanie. Wartość sprężynowania przede wszystkim zależy od zastosowanego materiału oraz geometrii części, a w skrajnych przypadkach odchyłka od nominału może wynosić lokalnie nawet kilkanaście milimetrów. Redukcja czasu realizacji i rozwój metalowych komponentów oraz coraz większe restrykcje dotyczące projektowania i produkowania narzędzi tłoczących generują dodatkowe koszty. Przewidywanie efektu sprężynowania metodą prób i błędów, a następnie korekcja dewiacji jest bardzo trudna oraz pracochłonna. Metody kompensacji numerycznej pozwalają otrzymać dokładny rezultat w stosunkowo krótkim czasie. Daje to dużą przewagę ekonomiczną, eliminując dodatkową obróbkę oraz pozwala na terminowe wykonanie narzędzia. Proces optymalizacji jest funkcją, która może odnosić się zarówno do poszczególnych operacji, jak i również uwzględniać etapy pośrednie w końcowym rezultacie, tym samym zwiększając dokładność. Wymogi jakościowe odnośnie produktów procesu tłoczenia blach są bardzo wysokie ze względu na technologie automatycznego montażu tłoczonych komponentów. Sprężynowanie, jako główne źródło niedokładności wytłoczek, jest funkcją danych materiałowych, kształtu narzędzi i parametrów procesu. Dlatego też, deformacja sprężynowania staje się krytycznym problemem, przede wszystkim dla stali UHSS przy złożonej geometrii części. Stąd też konieczne jest nie tylko znalezienie wielkości efektu sprężynowania, ale i jego uwzględnienie podczas wczesnego etapu projektowania przez projektantów narzędziowych.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 4; 2471-2478
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation analysis of fatigue strength in steel highway bridges
Autorzy:
Wysokowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/396392.pdf
Data publikacji:
2005
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
most drogowy
konstrukcje stalowe
wytrzymałość
zmęczenie
analiza symulacyjna
highway bridges
steel structures
fatique
simulation analysis
Opis:
In this paper, the determination in a theoretical way – by the simulation analysis - of the stress spectra and strength, as well the service life parameters for the structural elements of road bridges is presented. The analytically obtained results have been verified by the results from field tests of selected elements of steel road bridges under the service load. For the simulation calculations, a linear load model of road bridges (presented in the paper) has been applied, derived from author's measurements on structures and concerning traffic on the Polish urban and country roads and bridges. The presented studies and theoretical analyses have proved that the fatigue hazard exists also in road bridges and they have indicated what types of bridges, which bridge elements in what static schemes, which spans and under what service loads, are endangered by the fatigue hazard.
Źródło:
Civil and Environmental Engineering Reports; 2005, 1; 273-306
2080-5187
2450-8594
Pojawia się w:
Civil and Environmental Engineering Reports
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sprawdzenie prawidłowości założonych parametrów organizacyjnych i wydajnościowych procesu produkcyjnego sprężonych płyt kanałowych typu HC z uwzględnieniem warunków losowych
Checking the accuracy of parameters of the pre-tensioned hc slabs production process with reference to chance variations
Autorzy:
Nicał, A. K.
Grabowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/403241.pdf
Data publikacji:
2011
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
proces produkcyjny
płyta stropowa
analiza symulacyjna
warunki losowe
production process
slab
simulation analysis
chance wariations
Opis:
Celem referatu jest zbadanie, przy zastosowaniu metody symulacyjnej Monte Carlo, wpływu losowego rozkładu czasów trwania działań oraz operacji roboczych w ramach procesu produkcyjnego strunobetonowych wielootworowych płyt stropowych HC metodą ślizgową „Spiroll” na końcową wielkość parametrów produkcyjnych. Ciąg działań technologicznych występujących w całym procesie zobrazowano na schemacie technologiczno- funkcjonalnym, natomiast przykładowe czasy trwania działań roboczych pokazano na karcie operacji roboczej. Dodatkowo zdefiniowano przyczyny występowania różnych czasów trwania działań w ramach operacji roboczych i założono losowy ich rozkład. Wielkość dyspersji wokół wartości oczekiwanej na wykresie gęstości prawdopodobieństwa dla danej operacji roboczej uzależniona jest od jej stopnia mechanizacji. Uzyskane na podstawie badań rezultaty pozwalają stwierdzić, że założone na wstępie parametry organizacyjne i wydajnościowe są wysoce prawdopodobne to osiągnięcia.
The aim of the paper is to determine by means of the Monte Carlo simulation method the influence of random distributions of aggregated production activity durations, within the production process of pre-tensioned HC slabs using the Spiroll production system, on the production parameters. A sequence of technological activities is illustrated in the techno-functional diagram. The sample durations for production activities are shown on an operational schedule. Additionally, causes of the diverse durations of production activities have been defined. Depending on the degree of mechanization of production activities, the dispersion around the expected value of the assumed probability destiny functions can be larger or smaller. Obtained on the basis of the research results reveal that the production parameters, assumed at the beginning, are highly likely to achieve.
Źródło:
Budownictwo i Inżynieria Środowiska; 2011, 2, 3; 346-352
2081-3279
Pojawia się w:
Budownictwo i Inżynieria Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie metod symulacyjnych w analizie wielowymiarowych tablic wielodzielczych
On the Use of the Monte Carlo Methods in the Multidimensional Contingency Tables Analysis
Autorzy:
Kończak, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/588315.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Analiza symulacyjna
Metoda Monte Carlo
Testy statystyczne
Wnioskowanie statystyczne
Inferential statistics
Monte Carlo method
Simulation analysis
Statistical tests
Opis:
Recently the role of computer simulation methods in scientific research has significantly increased. In this paper the proposal of the use simulation methods to test for independence of some categorical variables with contingency tables is presented. The permutation test is used in this method. The comparison of obtained results and results of classically chi-square test of independence has been done. In presented examples the data from Polish General Public Opinion Poll have been used.
Źródło:
Studia Ekonomiczne; 2013, 133; 107-118
2083-8611
Pojawia się w:
Studia Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sterowanie neuronowe procesem przemiału cementu. Cz.2. Synteza regulatora neuronowego
Neurocontrol with process of the grinding of cement. Part 2. Synthesis of neurocontroller
Autorzy:
Bursy, G.
Powiązania:
https://bibliotekanauki.pl/articles/392418.pdf
Data publikacji:
2009
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Ceramiki i Materiałów Budowlanych
Tematy:
produkcja cementu
proces przemiału
młyn kulowy
sterowanie neuronowe
analiza symulacyjna
cement manufacturing
cement grinding process
ball mill
neurocontrol
simulation analysis
Opis:
Wysoka energochłonność procesów przemiałowych zmusza do poszukiwania nowych rozwiązań układów służących do przemiału surowców mineralnych. Złożoność procesów zachodzących podczas przemiału, determinuje stosowanie nowych narzędzi w układach sterowania takimi obiektami. W artykule podjęto próby zastosowania do rozwiązania tego zadania metod opartych na teorii sztucznych sieci neuronowych. W części pierwszej przedstawiono identyfikację procesu przemiałowego. W niniejszej (części 2) przedstawiono syntezę regulatora neuronowego oraz badania symulacyjne pracy regulatora bazującego na sztucznych sieciach neuronowych. Prezentowane opracowanie jest podsumowaniem rozprawy doktorskiej autora obronionej na Wydziale Elektrotechniki, Automatyki i Informatyki Politechniki Opolskiej.
High energy consumption of grinding processes forces to search for new solutions required for grinding mineral of raw materials. Complexity of grinding processes requires application of new tools to control these objects. In the report was carried out study of implementation of methods based on theory of artificial neuron grid. In part 1 was introduced identification of grinding process system. In this part was introduced synthesis of neurocontroller and simulation research of controller operation based on artificial neuron grid. The presentation is an author's summary of doctor's thesis carried out on Faculty of Electrical Engineering, Automatic Control and Computer Science of The Opole University of Technology.
Źródło:
Prace Instytutu Szkła, Ceramiki, Materiałów Ogniotrwałych i Budowlanych; 2009, R. 2, nr 4, 4; 123-135
1899-3230
Pojawia się w:
Prace Instytutu Szkła, Ceramiki, Materiałów Ogniotrwałych i Budowlanych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation and Casting Process of Aluminum Alloy Multi-Way Valve Body with Various Gating Systems
Autorzy:
Rong, L.
Lunjun, C.
Ming, S.
Qi, Z.
Yong, L.
Heng, W.
Powiązania:
https://bibliotekanauki.pl/articles/381887.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
casting process
aluminum alloy
valve body
gating system
simulation analysis
proces odlewniczy
stop aluminium
korpus zaworu
układ wlewowy
analiza symulacji
Opis:
In order to study the effects of various gating systems on the casting of a complex aluminum alloyed multi-way valve body, both software simulation analysis and optimization were carried out. Following, the aluminum alloyed multi-way valve body was cast to check the pouring of the aluminum alloy valve body. The computer simulation results demonstrated that compared to the single side casting mode, the casting method of both sides of the gating system would reduce the filling of the external gas, while the air contact time would be lower. Adversely, due to the pouring on both sides, the melt cannot reach at the same time, leading to the liquid metal speed into the cavity to differ, which affected the liquid metal filling stability. The riser unreasonable setting led to the solidification time extension, resulting in a high amount of casting defects during solidification. Also, both gating systems led the entire casting inconsequential solidification. To overcome the latter problems, a straight gate was set at the middle pouring and the horizontal gate diversion occurred on both sides of pouring, which could provide better casting results for the aluminum alloyed multi-valve body.
Źródło:
Archives of Foundry Engineering; 2018, 18, 2; 84-94
1897-3310
2299-2944
Pojawia się w:
Archives of Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Capacity assessment of the airport cargo screening system under disruptions
Ocena przepustowości systemu kontroli bezpieczeństwa cargo w porcie lotniczym w warunkach zakłóceń
Autorzy:
Skorupski, Jacek
Uchroński, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/38955788.pdf
Data publikacji:
2023
Wydawca:
Politechnika Warszawska, Wydział Transportu
Tematy:
air cargo
security screening
airport capacity
Petri nets
simulation analysis
cargo lotnicze
kontrola bezpieczeństwa
przepustowość lotniska
sieci Petriego
analiza symulacyjna
Opis:
Cargo shipments are a growing part of the transport carried out by many air carriers. One of the critical elements in this area of activity is shipment security inspection, which is a mandatory part of the transportation process. This article aimed to study the inspection system's capacity under disruption conditions and determine its dependence on possible technical and organizational improvements. For this purpose, simulation modeling was applied using a microscale model of the cargo security inspection process realized in a colored, timed, stochastic Petri net. Bayesian networks representing the actual process were used to validate the model. As a result of the research, experiments showed that for Katowice Airport in Pyrzowice, more advanced technical solutions can increase capacity by up to 50%. On the other hand, introducing modifications to the procedure, involving at least two checks using specialized assistive devices, can reduce it by up to 40%. Relatively small changes in capacity are expected with changes in the training and experience of screening operators. Based on these results, it can be recommended that airport managers consider using technical solutions with the parameters analyzed in the article. In addition, it is necessary to maintain the level of training at least at the current level. At the same time, any changes in control procedures should be made prudently, only when necessary, due to the need to strengthen the effectiveness of controls during periods of increased terrorist threat.
Przesyłki cargo stanowią coraz większą część przewozów realizowanych przez wielu przewoźników lotniczych. Jednym z kluczowych elementów w tym obszarze działalności jest kontrola bezpieczeństwa przesyłek, która jest obowiązkowym elementem procesu przewozowego. Celem artykułu było zbadanie przepustowością systemu kontroli w warunkach zakłóceń, a także określenie jej zależności od możliwych ulepszeń technicznych i organizacyjnych. W tym celu zastosowano modelowanie symulacyjne z wykorzystaniem mikroskalowego modelu procesu kontroli bezpieczeństwa cargo zrealizowanego w postaci kolorowanej, czasowej, stochastycznej sieci Petriego. Do walidacji modelu wykorzystano sieci Bayesowskie reprezentujące rzeczywisty przebieg procesu. W wyniku przeprowadzonych eksperymentów badawczych wykazano dla lotniska Katowice w Pyrzowicach, że użycie bardziej zaawansowanych rozwiązań technicznych może zwiększyć przepustowość nawet o 50%. Z kolei wprowadzenie modyfikacji procedury, polegające na co najmniej dwukrotnej kontroli z wykorzystaniem specjalizowanych urządzeń wspomagających, może doprowadzić do jej zmniejszenia nawet o 40%. Stosunkowo niewielkie zmiany przepustowości są spodziewane w przypadku zmian w zakresie wyszkolenia i doświadczenia operatorów kontroli bezpieczeństwa. Na podstawie tych wyników można rekomendować, aby zarządzający portem lotniczym rozważyli użycie rozwiązań technicznych o parametrach, które były analizowane w artykule. Dodatkowo, konieczne jest utrzymanie poziomu wyszkolenia na co najmniej dotychczasowym poziomie, zaś wszelkie zmiany procedur kontroli należy wprowadzać rozważnie, tylko wówczas kiedy jest to niezbędne z powodu konieczności wzmocnienia skuteczności kontroli w okresach zwiększonego zagrożenia terrorystycznego.
Źródło:
WUT Journal of Transportation Engineering; 2023, 136; 101-122
1230-9265
Pojawia się w:
WUT Journal of Transportation Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asymetryczny wpływ zmiany stopy procentowej WIBOR na stopy banków komercyjnych oraz gospodarkę Polski
Asymmetric impact of changes the WIBOR interest rate on commercial banks interest rates and the Polish economy
Autorzy:
Karp, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/596027.pdf
Data publikacji:
2015
Wydawca:
Łódzkie Towarzystwo Naukowe
Tematy:
stopy procentowe
progowe modele korekty błędem asymetryczność reakcji
analizy symulacyjne
interest rates
threshold error correction models asymmetric reactions
simulation analysis
Opis:
Gospodarka Polski narażona jest na oddziaływanie wielu egzogenicznych szoków, co jest cechą charakterystyczną otwartych gospodarek o małej i średniej wielkości. Wpływ zaburzeń ma charakter asymetryczny, co wymaga zastosowania odpowiednich procedur, umożliwiających testowanie hipotez ekonomicznych. W artykule analizowane są skutki zmiany stopy procentowej WIBOR. Wprowadzony impuls powoduje uruchomienie sprzężenia inflacyjnego i w konsekwencji reakcję całego systemu gospodarczego. W związku z tym odpowiednie analizy muszą być przeprowadzone na kompletnym modelu makroekonometrycznym. W tej roli został wykorzystany miesięczny model WM-1. Wyniki analiz symulacyjnych wskazują na zróżnicowanie oferty banków komercyjnych w zależności od kierunku zmiany. Pomimo iż impuls płynie ze strony sfery nominalnej, zmiany dotyczą także procesów produkcji, inwestycji i zatrudnienia, a więc sfery realnej, i utrzymują się przez okres znacznie dłuższy niż okres oddziaływania samego impulsu.
The Polish economy is influenced by many exogenous shocks, which is characteristic of small and medium-sized open economies. The impact of these impulses is asymmetric what requires the application of appropriate procedures to test economic hypotheses. The article analyze the effects of changes in the WIBOR interest rate. The impulse initiates the inflation loop and consequently the reaction of the whole economic system. Therefore the relevant analysis must be done on a complete macroeconometric model such as monthly model of the Polish economy WM-1. The results of the simulation analyzes shows the variability of interest rates offered by commercial banks depends on the direction of change. Although the initial impulse directly affects the nominal economy its impact influences the real economy as well (production, investment or employment).
Źródło:
Studia Prawno-Ekonomiczne; 2015, XCV (95); 261-287
0081-6841
Pojawia się w:
Studia Prawno-Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation analysis of the impact of container wagon pin configuration on the train loading time in the intermodal terminal
Autorzy:
Nehring, Karol
Kłodawski, Michał
Jachimowski, Roland
Klimek, Piotr
Vašek, Rostislav
Powiązania:
https://bibliotekanauki.pl/articles/2067402.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
container train
loading
intermodal terminal
wagon pin configuration
simulation analysis
FlexSim
pociąg kontenerowy
załadunek
terminal intermodalny
konfiguracja sworznia wagonu
analiza symulacyjna
Opis:
The article presents the issues of a container train loading at the land intermodal terminal. This issue was considered from the point of view of the distance covered by the loading devices and the duration of loading works, which was influenced by the arrangement of containers on the storage yard and the configuration of pins on the wagons. The conducted research was dictated by the small number of publications on loading an intermodal train, especially from the point of view of pin configuration on wagons. The vast majority of the literature is devoted in this field to marine intermodal terminals, which operating characteristics are different from inland terminals. The importance of this problem resulting from the growing turnover of containers transported by rail transport was also pointed out. The systematic increase of this type of transport and the depletion of the intermodal services' operating capability makes it necessary to improve the train loading process. For the purposes of the research, the issues of containers of various sizes loading onto wagons planning with various pin configurations were presented. A literature review was carried out in the field of train loading methods and strategies. A mathematical model was developed for the decision situation under consideration. The equations defining the most important elements of the considered problem were presented in the general form. This model was implemented in the FlexSim simulation environment. The constructed simulation model was used to develop 12 variants of the approach to an intermodal train loading. The train loading tests were performed both for the random arrangement of containers on the storage yard and for the random arrangement of pins on the wagons. The obtained results made it possible to determine how the knowledge of the arrangement of pins on the wagons influences the planning of train loading and increases the efficiency of loading devices.
Źródło:
Archives of Transport; 2021, 60, 4; 155--169
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza rozkładu naprężeń/odkształceń w skojarzeniu żeliwo-kompozyt w warunkach smarowania olejem za pomocą MES
Distribution of stresses/strains in cast iron-composite contact in lubricated conditions by means of FEM
Autorzy:
Bąkowski, H.
Powiązania:
https://bibliotekanauki.pl/articles/197743.pdf
Data publikacji:
2012
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
silnik spalinowy
tuleja cylindrowa
tarcie
rozkład naprężenia
badanie symulacyjne
metoda elementów skończonych (MES)
combustion engine
cylinder sleeve
friction
stress distribution
simulation analysis
FEM
Opis:
W artykule przedstawiono model występujący zarówno w skojarzeniu pierścień tłokowy–tuleja cylindrowa, jak i tłok–tuleja cylindrowa. Rzeczywisty kształt i wielkość fazy zbrojącej (Al2O3) określono na podstawie badań metalograficznych i statystycznych. W ten sposób odzwierciedlono rzeczywisty kształt twardych cząstek fazy zbrojącej. W badanym skojarzeniu wprowadzono medium smarne w postaci oleju. Przeprowadzone badania symulacyjne miały na celu określenia rozkładu i wartości naprężeń/przemieszczeń w warunkach ekstremalnej eksploatacji.
In this paper presented model occurring in piston ring – cylinder linear and piston – cylinder liner. The materials in these contacts were made from composites and casts iron. The real shape and size of reinforcement phases (Al2O3) in composite were determined on the basis of metallographic and statistic examination. On the basis of these examination could be reconstruction the real shape of reinforcement phase hard particles. The main aims of the simulation research were determination of stresses and strains in extreme service condition.
Źródło:
Zeszyty Naukowe. Transport / Politechnika Śląska; 2012, 74; 5-10
0209-3324
2450-1549
Pojawia się w:
Zeszyty Naukowe. Transport / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation-Based Risk Analysis of Maritime Transit Traffic in the Strait of Istanbul
Autorzy:
Ozbas, B.
Or, I.
Uluscu, O. S.
Atiok, T.
Powiązania:
https://bibliotekanauki.pl/articles/117473.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Risk Analysis
Strait of Istanbul
Maritime Transit Traffic
Traffic Rules
Traffic Regulations
risk assessment
Simulation-Based Analysis
safety at sea
Opis:
In this manuscript, development and preliminary results of a simulation based risk modeling study for the Strait of Istanbul is presented. The goal of this research is to analyze the risks involved in the transit vessel traffic in the Strait of Istanbul. In the first step of the study, the transit vessel traffic system in the Strait of Istanbul has been investigated and a simulation model has been developed. The model gives due consideration to current traffic rules and regulations, transit vessel profiles and schedules, pilotage and tugboat services, local traffic, meteorological and geographical conditions. Regarding risk assessment, two sets of factors are used to evaluate the risk of accident in the Strait: the proba-bility of an accident and its potential consequences, as estimated and evaluated at various points along the Strait. Experience has shown that maritime accident occurrences can be very dissimilar from one another and therefore, probabilistic analysis of accidents should not be done independent of the factors affecting them. Thus, in this study, we have focused on the conditional probability of an accident, under a given setting of various accident causing factors. Unfortunately, historical accident data is by far insufficient for a proper sta-tistical consideration of all possible settings of these factors. Therefore, subject-expert opinion is relied upon in estimating these conditional accident probabilities. Assessment of the consequences of a given accident (in terms of its effects on human life, traffic efficiency, property and environment) was also accomplished using a similar approach. Finally, by integrating these assessments into the developed simulation model, the risks observed by each vessel at each risk slice are calculated in regard to the natural and man-made conditions surrounding. A sce-nario analysis is performed to evaluate the characteristics of the accident risk as the vessel moves along the Strait. This analysis allows us to investigate how various factors impact risk. These factors include vessel ar-rival rates, scheduling policies, pilotage service, overtaking and pursuit rules, and local traffic density. Policy indications are made based on the results of these scenarios.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2009, 3, 3; 295-300
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the Generalised Distance Measure to Location Selection During Order-Picking
Autorzy:
Dmytrów, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/578508.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Analiza symulacyjna
Taksonomiczna Miara Atrakcyjności Lokalizacji
Uogólniona miara odległości
Wielokryterialne podejmowanie decyzji
Generalised Distance Measure
Multiple-criteria decision making
Simulation analysis
Taxonomic Measure of Location’s Attractiveness
Opis:
When a shared storage system is used, the selection of locations from which products should be picked becomes a significant decision problem. Every storage location can be described using several criteria, such as: storage time, distance from the I/O point, degree of demand satisfaction, the number of other products to be picked near the analysed location, or others. Based on such criteria, a synthetic variable can be created to rank all these locations; the highest-ranking one is selected. Such a ranking is created using the Generalised Distance Measure (GDM); the selected locations and the picker’s route based on them are compared to the results obtained using the Taxonomic Measure of Location’s Attractiveness (TMAL). Both route length and picking time are compared. Also, the influence of the system of criteria weights within each method on the route length and the picking time is analysed using simulation methods.
Źródło:
Multiple Criteria Decision Making; 2018, 13; 103-115
2084-1531
Pojawia się w:
Multiple Criteria Decision Making
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Makroekonomiczne czynniki ryzyka kredytowego w sektorze bankowym w Polsce
Macroeconomic Credit Risk Factors in Poland’s Banking Sector
Autorzy:
Wdowiński, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/574992.pdf
Data publikacji:
2014-08-31
Wydawca:
Szkoła Główna Handlowa w Warszawie. Kolegium Analiz Ekonomicznych
Tematy:
sektor bankowy
ryzyko kredytowe
testy warunków skrajnych
model korekty błędem
analiza symulacyjna
scenariusz makroekonomiczny
banking sector
credit risk
stress testing
error correction model
simulation analysis
macroeconomic scenario
Opis:
The article explores key micro- and macroeconomic factors with an impact on credit risk and analyzes the credit risk model prevalent in Poland’s banking sector. Credit risk is one of the most important risks in the banking sector, the author says. He adds that risk management should be subject to strict owner control and regulatory and supervisory measures. On the basis of quarterly data for a period from the first quarter of 1997 to the second quarter of 2013, Wdowiński estimated an error correction model for aggregate credit risk in Poland, as measured by the proportion of non‑performing loans (NPLs) in total loans. The key macroeconomic factors considered by the author were GDP, the interest rate, the unemployment rate, and the exchange rate. An ex post simulation for the 2008–2012 period, based on an adverse macroeconomic scenario for Poland, showed that such a scenario could lead to a marked increase in credit risk for non‑financial enterprises and households, Wdowiński says. As a result of this scenario, the banking sector could be affected by a significant decline in activity and its financial position would deteriorate. This would mean fewer investment opportunities for banks and a decline in their capital position, which would reduce their ability to absorb losses. Such a situation, the author concludes, could lead to “second‑round” effects based on limiting financing for the real economy due to increased credit risk and increased lending margins.
Celem artykułu jest przegląd głównych czynników mikro- i makroekonomicznych wpływających na ryzyko kredytowe oraz analiza modelu ryzyka kredytowego w sektorze bankowym w Polsce. Ryzyko kredytowe jest jednym z najważniejszych rodzajów ryzyka jakie podejmuje się w sektorze bankowym. Zarządzanie tym ryzykiem powinno podlegać ścisłej kontroli zarówno ze strony właścicieli, jak i poprzez działania o charakterze regulacyjno‑nadzorczym. Na podstawie kwartalnych danych statystycznych w okresie od I kw. 1997 r. do II kw. 2013 r. oszacowano model korekty błędem dla zagregowanego ryzyka kredytowego w Polsce, mierzonego za pomocą odsetka kredytów z utratą wartości w kredytach ogółem. Za najważniejsze czynniki makroekonomiczne przyjęto PKB, stopę procentową, stopę bezrobocia oraz kurs walutowy. Przeprowadzono symulację ex post w latach 2008-2012 opierając się na scenariuszu makroekonomicznym obrazującym głęboką recesję gospodarczą w Polsce. Pokazano, że jego realizacja mogłaby spowodować wyraźny wzrost ryzyka kredytowego zarówno w odniesieniu do przedsiębiorstw niefinansowych, jak i gospodarstw domowych. W wyniku materializacji tego scenariusza sektor bankowy mógłby zostać dotknięty znacznym spadkiem aktywności i pogorszeniem się wyniku finansowego. Oznaczałoby to mniejsze możliwości inwestycyjne banków i pogorszenie się ich pozycji kapitałowej, co zmniejszyłoby ich zdolność do absorpcji strat. Sytuacja taka mogłaby doprowadzić do efektów „drugiej rundy” polegających na ograniczeniu finansowania sfery realnej gospodarki wskutek wzrostu ryzyka kredytowego i wzrostu marż kredytowych.
Źródło:
Gospodarka Narodowa. The Polish Journal of Economics; 2014, 272, 4; 55-77
2300-5238
Pojawia się w:
Gospodarka Narodowa. The Polish Journal of Economics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
PUMA-TCS - nowy protokół warstwy MAC ze wsparciem jakości świadczonych usług
PUMA-TCS - a new MAC layer protocol with QoS support
Autorzy:
Natkaniec, M.
Kosek-Szott, K.
Szott, S.
Powiązania:
https://bibliotekanauki.pl/articles/298503.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
protokół PUMA
funkcja EDCA
jakość obsługi QoS
różnicowanie ruchu
mechanizm priorytetów
analiza symulacyjna
PUMA protocol
EDCA function
quality of service (QoS)
traffic differentiation
priorities mechanism
simulation analysis
Opis:
W ostatnich latach obserwujemy rosnącą potrzebę zapewnienia odpowiedniej jakości świadczonych usług w lokalnych sieciach bezprzewodowych. W tym celu opracowany został standard IEEE 802.11e. Niestety, jak pokazują badania naukowe, nie jest on pozbawiony wad. W prezentowanej pracy zaproponowano nowy protokół o nazwie PUMA-TCS (Priority Unavoidable Multiple Access with Traffic Category Support) pozwalający na lepsze różnicowanie ruchu oraz większe gwarancje świadczenia usług z określoną jakością. W pracy zawarto również wyniki badań oraz analizę porównawczą obu protokołów, przeprowadzonych przy użyciu wybranych symulatorów sieci bezprzewodowych, co pozwoliło wskazać zalety oraz wady badanych metod dostępu.
There is a growing interest in QoS provisioning for wireless local area networks in recent years. Because of this, the IEEE 802.11e standard was introduced. Unfortunately, a few research papers show, that it has a number of serious flaws. The presented work describes a new protocol called PUMA-TCS (Priority Unavoidable Multiple Access with Traffic Category Support), that allows for better than IEEE 802.11e traffic differentiation and QoS guarantees. Research results and comparative analysis of protocols using selected simulators are also included in the paper. This allows to reveal a pros and cons of both channel access schemes.
Źródło:
Telekomunikacja Cyfrowa : technologie i usługi; 2010-2011, 10; 44-58
1505-9405
Pojawia się w:
Telekomunikacja Cyfrowa : technologie i usługi
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selection of a Container Storage Strategy at the Rail-road Intermodal Terminal as a Function of Minimization of the Energy Expenditure of Transshipment Devices and CO2 Emissions
Dobór strategii składowania kontenerów w lądowym terminalu intermodalnym w funkcji minimalizacji wydatku energetycznego urządzeń przeładunkowych i emisji CO2
Autorzy:
Jachimowski, R.
Szczepański, E.
Kłodawski, M.
Markowska, K.
Dąbrowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1813739.pdf
Data publikacji:
2018
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
intermodal transport
rail-road intermodal terminal
containers storage strategies
CO2 emission
simulation analysis
FlexSim
transport intermodalny
terminal intermodalny kolejowo-drogowy
strategie składowania kontenerów
emisja CO2
analiza symulacyjna
Opis:
The article presents the problem of containers storage on a storage yard in an rail-road intermodal land and the emission of harmful exhaust gases into the atmosphere. This issue was considered from the point of view of the distance traveled by transshipment devices, the duration of loading work and the resulting energy expenditure and CO2 emissions. The research was dictated by the current limited number of publications in the area of the distribution of containers on storage yards in rail-road intermodal terminals. The vast majority of the literature is devoted in this field to marine intermodal terminals, which operating characteristics are different from inland terminals. The importance of this problem resulting from the growing turnover of containers transported by rail transport was also pointed out. The systematic increase of this type of transport and the depletion of the intermodal services' operating capability makes it necessary to improve the processes taking place in the storage area. The possibility of improving these processes in addition to the use of computer tools is also realized through the use of modern transshipment devices. Depending on the area of their operation and the scope of their application, these devices use various types of power supply, which affect environmental pollution. In the case of gantry cranes considered in this article, their power supply may come from both combustion engines, hybrids and electric engines. Therefore, from the point of view of minimization of harmful exhaust gases emissions into the atmosphere, in the article, the problem of choosing the device for carrying out transshipment tasks was also taken up. For the purposes of the research, the processes of container handling in the rail-road intermodal terminal have been presented in detail. A review of literature in the field of container storage methods and strategies was carried out. The considered container reloading processes in the wagon-yard relation were modeled in the FlexSim simulation environment. The constructed simulation model was used to develop 5 variants of the distribution of containers on the storage yard as a function of their location on the train. Container deployments on the storage yard were carried out for both random and fixed distribution of containers on the train. In the case of a random arrangement of containers on the train, the tests were carried out for 100 replications. On the basis of simulation tests, the distance covered by the transshipment device (RTG crane) and the time of carrying out the loading tasks in particular variants were determined. Using the crane data provided by the crane manufacturer, the energy expenditure was calculated in individual variants for different power supply methods (combustion engine, hybrid, electric engine). The obtained results allowed the selection of the best strategy for containers storage, taking into account the amount of CO2 emitted to the atmosphere by transshipment devices.
W artykule przedstawiono problematykę składowania kontenerów na placu składowym w lądowym terminalu intermodalnym i związaną z tym emisją szkodliwych związków spalin do atmosfery. Zagadnienie to rozważano z punktu widzenia dystansu pokonywanego przez urządzenia ładunkowe, czasu trwania prac ładunkowych oraz wynikającego z tego wydatku energetycznego i emisją CO2. Przeprowadzone badania podyktowane były dotychczasową niewielką liczbą publikacji na temat badania rozmieszczenia kontenerów na placach składowych w lądowych, kolejowo-drogowych terminala intermodalnych. Zdecydowana większość literatury poświęcona jest w tym zakresie morskim terminalom intermodalnym, których charakterystyka pracy różni się od tej w terminalach lądowych. Wskazano także na istotność tego problemu wynikającą z rosnących obrotów kontenerów przewożonych transportem kolejowym. Systematyczny wzrost tych przewozów i wyczerpywanie się zdolności obsługowych terminali intermodalnych powoduje konieczność usprawniania zachodzących tam procesów. Możliwość usprawniania tych procesów oprócz zastosowania narzędzi komputerowych realizowana jest także dzięki wykorzystaniu nowoczesnych urządzeń przeładunkowych. Urządzenia te w zależności od obszaru ich działania i zakresu ich zastosowania wykorzystują różne rodzaje zasilania, które w większym, bądź mniejszym stopniu wpływają na zanieczyszczenia środowiska. W przypadku rozważanych w niniejszym artykule suwnic jezdniowych, zasilanie to pochodzić może zarówno z silników spalinowych, hybrydowych jak i silników elektrycznych. Stąd też z punktu widzenia minimalizacji wielkości emisji szkodliwych związków spalin do atmosfery w artykule podjęto także problematykę wyboru urządzenia do realizacji zadań przeładunkowych. Na potrzeby badań szczegółowo przedstawiono procesy obsługi kontenera w lądowym terminalu intermodalnym. Dokonano przeglądu literatury w zakresie metod i strategii składowania kontenerów. Rozważane procesy przeładunku kontenerów w relacji wagon-plac składowy zamodelowano w środowisku symulacyjnym FlexSim. Zbudowany model symulacyjny posłużył do opracowania 5 wariantów rozmieszczenia kontenerów na placu w funkcji ich rozmieszczenia na pociągu. Badania rozmieszczenia kontenerów na placu składowym wykonywano zarówno dla losowego jak i ustalonego rozmieszczenie kontenerów na pociągu. W przypadku losowego rozmieszczenia kontenerów na pociągu próby wykonywano dla 100 powtórzeń. Na podstawie badań symulacyjnych określono dystans pokonywany przez urządzenie przeładunkowe (suwnicę RTG) oraz czas realizacji prac ładunkowych w poszczególnych wariantach. Wykorzystując podawane przez producenta suwnic dane o wielkości zużywanej przez suwnicę energii obliczono jej wydatek energetyczny w poszczególnych wariantach dla różnych sposobów zasilania (silnik spalinowy, hybrydowy, elektryczny). Uzyskane wyniki pozwoliły na wybór najlepszej spośród rozważanych, strategii składowania kontenerów na placu przy uwzględnieniu wielkości emitowanego przez urządzenia przeładunkowe CO2 do atmosfery.
Źródło:
Rocznik Ochrona Środowiska; 2018, Tom 20, cz. 2; 965-988
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Comprehensive Overview of the Impacting Factors on a Lithium-Ion-Battery’s Overall Efficiency
Autorzy:
Kremzow-Tennie, Simeon
Scholz, Tobias
Pautzke, Friedbert
Popp, Alexander
Fechtner, Heiko
Schmuelling, Benedikt
Powiązania:
https://bibliotekanauki.pl/articles/2175925.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
battery simulation
battery efficiency
component analysis
simulation technology
battery analysis
Opis:
This comprehensive overview of the impacting factors on lithium-ion-battery’s (LIB) overall efficiency presents the most relevant influencing factors on a battery’s performance. Dissected into their respective short-term and long-term influences, the working principles behind the efficiency influencing factors are presented. With a strong focus on battery characterisation, charge-profiles and battery management systems (BMSs), the authors present results of their own practical research with a detailed literary analysis, allowing a broad coverage of the complex topic. Finally, the authors present a principle model that indicates the interactions be-tween the different involved components of the battery.
Źródło:
Power Electronics and Drives; 2022, 7, 42; 9--28
2451-0262
2543-4292
Pojawia się w:
Power Electronics and Drives
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrated Simulation and Regression Framework for Delivery Management in E-commerce
Wykorzystanie połączenia symulacji i regresji dla problemu zarządzania dostawami w sektorze e-commerce
Autorzy:
Wiśniewski, Tomasz
Powiązania:
https://bibliotekanauki.pl/articles/526371.pdf
Data publikacji:
2019-05-06
Wydawca:
Uniwersytet Warszawski. Wydawnictwo Naukowe Wydziału Zarządzania
Tematy:
delivery management simulation modelling regression analysis e-commerce
supply chain
zarządzanie dostawami modelowanie symulacyjne
analiza regresji
handel elektroniczny
łańcuch dostaw
Opis:
Problems with commodities and the delivery of products have accompanied trade since its beginnings. It is not possible to stock up, as there will always be limitations – of storage space, resources or financial resources. The e-commerce sector in the age of Industry 4.0 era faces its own specific problems: on the one hand, customers want customised products fast, on the other hand, shops have to lower storage costs and efficiently manage the supply chain. The paper proposes a framework of simulation modelling with a regression module for shops operating in the e-commerce sector; it is a tool for decision-makers that simulates the ordering and delivering process with a varying number of products, suppliers and a varying demand. The aim is to define a novel approach where computer simulation and regression models are integrated and combined in order to provide decision-makers with information about the average delivery time to customers ordering online products and possible delays. The results of analyses show 90% reliability of the regression model in terms of changes in the average delivery time depending on number of products sold by the shop, demand fluctuation, the number of distributors and the average delivery time of products from the distributor.
Problemy z zapasami i dostawą produktów towarzyszyły handlowi od początku jego istnienia. Nie jest możliwe utrzymanie cały czas wysokiego stanu zapasów, ponieważ zawsze będą istniały ograniczenia – powierzchni magazynowej, zasobów materialnych lub zasobów finansowych. Sektor e-commerce w dobie Przemysłu 4.0 boryka się z własnymi specyficznymi problemami: z jednej strony klienci chcą szybko dostać dostosowane do swoich potrzeb produkty, z drugiej zaś – sklepy muszą obniżyć koszty magazynowania i efektywnie zarządzać łańcuchem dostaw. W artykule proponuje się połączenie modelowania symulacyjnego z modułem regresji dla sklepów działających w sektorze handlu elektronicznego; jest to narzędzie dla decydentów, które symuluje proces zamawiania i dostarczania dla różnej liczby produktów, dostawców i zróżnicowanego popytu. Celem artykułu jest zdefiniowanie nowego podejścia, w którym symulacja komputerowa i modele regresji są zintegrowane i połączone w celu dostarczenia decydentom informacji o średnim czasie dostawy i ewentualnych opóźnieniach do klientów zamawiających produkty online. Wyniki analiz modelu regresji pokazują iż 90% zmian średniego czasu dostawy zależy od liczby produktów sprzedawanych przez sklep, wahań popytu, liczby dystrybutorów oraz średniego czasu dostawy produktów od dystrybutora.
Źródło:
Problemy Zarządzania; 2019, 2/2019 (82); 205-217
1644-9584
Pojawia się w:
Problemy Zarządzania
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automation of the casting process by the use of simulation software
Autorzy:
Trebuňa, P.
Pekarčíková, M.
Kronová, J.
Powiązania:
https://bibliotekanauki.pl/articles/407215.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analysis
process
automation
model
simulation
Opis:
Technological development offers a wide range of new possibilities for implementation of production processes. Continual production development is the main key to success and competitiveness improvement, labour productivity and image-building for all manufacturing companies. The article deals with designing of new workplace with implementation and utilization of automated robot for faster and safer handling of cast stock. The new layout of workplace is created in software Process Simulate.
Źródło:
Management and Production Engineering Review; 2018, 9, 1; 82-89
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of a calculation fem model of the test static set-up of pipe conveyor for analysis of contact forces
Autorzy:
Fedorko, G.
Molnár, V.
Powiązania:
https://bibliotekanauki.pl/articles/102281.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
pipe conveyor
simulation
analysis
contact forces
Opis:
Experimental research in the field of pipe conveyors is a difficult matter and yet necessary in order to answer the questions regarding the motion resistances and contact resistances of pipe conveyors, loading of the conveyor belts etc. These research activities can be performed not only during the actual operation of pipe conveyors, but also by means of the special laboratory test set-ups combined with the application of the computational simulation models. The main task of this paper is to assess the creation of a suitable simulation model of the test set-up for a specified pipe conveyor developed with regard to realisation of the FEM analyses, using the software product Abaqus, as well as presentation of its application possibilities.
Źródło:
Advances in Science and Technology. Research Journal; 2017, 11, 2; 220-225
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical investigations on vibrating motion with inertial load of vibratory pile hammer stiffly coupled with excavator
Autorzy:
Osiński, J.
Miedzińska, D.
Powiązania:
https://bibliotekanauki.pl/articles/247648.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
elastomer
vibrations
simulation
resonance
numerical analysis
Opis:
A vibratory pile hammer (VPH) is a mechanical device used to drive steel piles as well as tube piles into soil to provide foundation support for buildings or other structures. In order to increase the stability and the efficiency of the VPH work in the over-resonance frequency, a new VPH construction was developed in the Military University of Technology. The new VPH contains a system of counter-rotating eccentric weights, powered by hydraulic motors, and designed in such a way that horizontal vibrations cancel out, while vertical vibrations are transmitted into the pile. This system is suspended in the static parts by the adaptive variable stiffness pillows based on a smart material, magnetorheological elastomer (MRE), which rheological and mechanical properties can be reversibly and rapidly controlled by an external magnetic field. The work presented in the paper is a part of the modified VPH construction design process. It concerns the development of the numerical model of the VPH and soil interaction that will describe resonance conditions, resonance frequencies with consideration of soil susceptibility, coupling phenomenon and elastomer changeable stiffness. On the base of developed theoretical equations, the frequency of VPH piling will be regulated to assure the over-resonance work.
Źródło:
Journal of KONES; 2014, 21, 1; 189-195
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determining the waterway parameters based on statistical data from simulation trials by means of regression method
Autorzy:
Gucma, L.
Powiązania:
https://bibliotekanauki.pl/articles/320851.pdf
Data publikacji:
2000
Wydawca:
Polskie Forum Nawigacyjne
Tematy:
navigation
waterway
computer simulation
statistical analysis
Opis:
Paper presents method of determining waterway parameters by means of multiple and linear regression method. The statistical data from computer simulation model are applied to determine waterway parameters. The method can be used for designing water areas and is more accurate than analytical method and less expensive than simulation one.
Źródło:
Annual of Navigation; 2000, 2; 37-45
1640-8632
Pojawia się w:
Annual of Navigation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Impact of Assembly Interference on Stresses in the Die Tool System During Bolt Forging
Autorzy:
Nowotyńska, I.
Kut, S.
Osetek, M.
Powiązania:
https://bibliotekanauki.pl/articles/353903.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
forging
modelling
simulation
bolts
stress analysis
Opis:
The article presents an analysis of stresses in the current tool system of the die during the implementation of the third forging operation of the screw M12 class 10.9 with cylinder head and hexagonal socket. It was assumed that the level of negative cracking due to stress can be reduced by using a mounting interference between the die and the tube blank. Due to the design of the tool system value of the die, the interference value cannot be too large. Therefore, an analysis of the influence of the interference between the die and the tube blank in a die tool system on the value and distribution of stresses in the individual components. An analysis of the assembly stresses and the stresses occurring during the process of deformation of the shaped head of the screw was done. The calculations were performed using a commercial software package MARC / Mentat.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1471-1478
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy and economic analysis of the use of photovoltaic in energy systems
Autorzy:
Szczerbowski, R.
Powiązania:
https://bibliotekanauki.pl/articles/97295.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
photovoltaic
renevable energy sources
energy analysis
economic analysis
simulation modelling
Opis:
Energy policy of Poland in a balanced way has to provide security of energy supply, increase the use of its own resources and promote the sustainable development of different electricity generation technologies. The established aims of climate and energy policy will be difficult to achieve without efficient technologies based on distributed generation. In this context, the importance of the development and use of photovoltaic systems is growing. Photovoltaics is one of the most promising technologies and the possibilities of its use in various scale energy systems make it an effective and safe source of energy and an important part of a stable and independent energy mix in the future.
Źródło:
Computer Applications in Electrical Engineering; 2013, 11; 416-422
1508-4248
Pojawia się w:
Computer Applications in Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Several sets of assumptions for the Monte Carlo simulation for a more precise analysis of enterprise risk
Autorzy:
Kaczmarzyk, Jan
Powiązania:
https://bibliotekanauki.pl/articles/425026.pdf
Data publikacji:
2019
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
corporate finance
risk analysis
Monte Carlo simulation
Opis:
The traditional methods of risk quantification include a sensitivity analysis, a scenario analysis and a historical simulation. The true nature of risk factors changes is ignored in the traditional ‘ceteris paribus’ approach to a sensitivity analysis, hence it can be reflected in a scenario analysis and a historical simulation. The most significant disadvantage of a scenario analysis is the limited number of scenarios, whereas a historical simulation depends on historical data availability and adequacy. The Monte Carlo simulation is a clear answer to the limitations of traditional methods. The changes of risk factors reflected in the Monte Carlo simulation are simultaneous, non-linear and interdependent. The most important aspect of this method is the stage of taking up the assumptions. The purpose of the paper is to indicate that considering several reasonable sets of assumptions for the Monte Carlo simulation simultaneously can bring even more comprehensive information about enterprise risk.
Źródło:
Econometrics. Ekonometria. Advances in Applied Data Analytics; 2019, 23, 4; 80-95
1507-3866
Pojawia się w:
Econometrics. Ekonometria. Advances in Applied Data Analytics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A computational fluid flow analysis of a disc valve system
Autorzy:
Czop, P.
Śliwa, P.
Gniłka, J.
Gąsiorek, D.
Wszołek, G.
Powiązania:
https://bibliotekanauki.pl/articles/244640.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
valve system
computational fluid flow analysis
simulation
Opis:
Noise concerns in shock absorbers can be divided into two categories. The first is fluid flow noise, or “swish noise”, caused by the oil being forced through openings in the valves. The type and temperature of the oil, its velocity and the orifice geometry all have an effect on this. In addition, the structural design of the shock absorber shell may either reduce or amplify the noise. The second type of shock absorber noise is often described as regular operational noise or “chuckle noise”. It can be observed in vehicles during low-displacement, higher-frequency events, such as driving over a slightly rough road. This effect measurable as a force discontinuity into the vehicle and can come from a number of sources in the shock absorber, e.g. hydraulic transitions. It is often traceable to the valve discs closing and opening, but can also be caused by cavitation/aeration in the oil and air being pulled through the valves. The work on noise improvement reported in this paper has been started using conventional shock absorbers to be extended and will cover in the future variable damping shock systems as well. The paper gives an overview about the configurations of a typical valve system including three basic regimes of operation, which correspond to the amount of oil flowing through a valve cavity. The aim of this work was to propose a finite element fluid flow model, which can be used in order to reduce the velocity of fluid flow through a cavity of a shock absorber valve. High flow velocity can cause high-content frequency vibrations and, in turn, audible noise. The model will be used for initial screening of new valve concepts and on the other hand to improve the currently use ones.
Źródło:
Journal of KONES; 2011, 18, 1; 117-122
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie podejścia rozmytego do konstrukcji wskaźników oceny stanu przedsiębiorstwa
Using fuzzy approach to the construction of indicators for enterprise state evaluation
Autorzy:
Rozenberg, Leonard
Powiązania:
https://bibliotekanauki.pl/articles/431860.pdf
Data publikacji:
2014
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
ratio analysis
fuzzy approach
rationalization
modelling
simulation
Opis:
The paper shows an original approach concept to the problem of determining the current state of company finance, based on a theory similar to the Austrian economic school, supplemented by fuzzy approach. The article presents the analysis offering an original approach to solve the problem as well as a discussion and initial verification of such an approach.
Źródło:
Informatyka Ekonomiczna; 2014, 1(31); 384-394
1507-3858
Pojawia się w:
Informatyka Ekonomiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Process of separating acetonitrile and water using LTTMs as entrainer
Autorzy:
Li, Chengshuai
Ma, Wencheng
Powiązania:
https://bibliotekanauki.pl/articles/2081511.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
LTTMs
ACN
Simulation
Extraction distillation
Sensitivity analysis
Opis:
New extractive distillation confi gurations, which use low transition temperature mixtures (LTTMs) as entrainers, have attracted widespread attention among scholars due to their green processes. Furthermore, the design and comparison of different processes can promote the application of new solvents in the future. In this study, two extractive distillation processes, the extractive distillation column (ED) and the extraction dividing wall column (EDW), were selected from previous work. The separation process of acetonitrile (ACN)-water ternary mixtures was studied, and GC3:1(choline chloride/glycolic acid mixture (molar mass 1:3)) and EC2:1((choline chloride/ethylene glycol 1:2 molar mass) were used as entrainers. Minimum consumption energy and the purity of ACN and water were set as the goals, and our sensitivity analysis and economic evaluation results showed that both ED and EDW were effective. As a result, LTTMs can be used in extractive distillation for azeotrope separation.
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 4; 1-9
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Intelligent hybrid material slide component for machine tools
Autorzy:
Möhring, H. C.
Wiederkehr, P.
Baumann, J.
König, A.
Spieker, C.
Müller, M.
Powiązania:
https://bibliotekanauki.pl/articles/100179.pdf
Data publikacji:
2017
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
process stability simulation
thermal analysis
machine tool
Opis:
In mid-scale and large five axis overhead gantry type milling machines, the vertical z-slide (ram) often constitutes one of the most sensitive and critical components regarding stiffness, structural vibrations and thermal influences. During machining, the z-slide is loaded by (quasi-) static process and drive forces, transient acceleration forces, periodic excitations by the tool engagement, as well as by thermal effects resulting from altering ambient conditions, heated chips, cooling lubricant and power losses in drives, guides and bearings. Deflections, thermal deformations and vibrations of the z-slide lead to geometric machining errors and inacceptable surface location errors at the workpieces. Furthermore, instable cutting conditions and regenerative chatter limit applicable material removal rates and, thus, productivity. In this work, a newly developed hybrid material structure for an exemplary z-slide, involving metal parts and mineral cast, is introduced. Structural optimization methods as well as process simulation techniques were applied in order to derive the final design solution. The integration of active cooling circuits for thermal stabilization is investigated and the use of fibre optical strain sensors is analysed with respect to a state monitoring of the machine tool component.
Źródło:
Journal of Machine Engineering; 2017, 17, 1; 17-30
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parametric analysis of automotive mechatronic systems
Autorzy:
Puchalski, A.
Powiązania:
https://bibliotekanauki.pl/articles/246388.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
automotive mechatronics
parametric analysis
modelling and simulation
Opis:
The paper presents the analysis results of the fan system using hardware/software multi-technology language VHDL-AMS (IEEE 1076.1) and System Vision design platform. The analysis was performed in the time domain for the selected sweep values of the component parameters. The sensitivity analysis was used to vary selected, user-specified percentage of rated values . The parameters were arranged according to the effect on the selected waveforms. The further analysis was performed using statistic method Monte Carlo (MC) and Worst Case (WCA). Results of simulation are presented and the advantage of MC simulation over sensitivity analysis was emphasized. Post processing measurement tools of MC results and calculator with the standard mathematical operators and advanced statistic functions were used to picture the system performance versus run number and to determine correlations between devices parameters and system performance. The obtained characteristics enable the designer to evaluate the reliability of the system when manufactured in the large scale and to state the worst case limits for the project.
Źródło:
Journal of KONES; 2010, 17, 2; 403-407
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparative analysis of the principal component method and parallel analysis in working with official statistical data
Autorzy:
Holubova, Halyna
Powiązania:
https://bibliotekanauki.pl/articles/10559806.pdf
Data publikacji:
2023-02-24
Wydawca:
Główny Urząd Statystyczny
Tematy:
principal components
principal component analysis
factor analysis
Kaiser criterion
рarallel analysis
simulation
Opis:
The dynamic development of the digitized society generates large-scale information data flows. Therefore, data need to be compressed in a way allowing its content to remain complete and informative. In order for the above to be achieved, it is advisable to use the principal component method whose main task is to reduce the dimension of multidimensional space with a minimal loss of information. The article describes the basic conceptual approaches to the definition of principle components. Moreover, the methodological principles of selecting the main components are presented. Among the many ways to select principle components, the easiest way is selecting the first k-number of components with the largest eigenvalues or to determine the percentage of the total variance explained by each component. Many statistical data packages often use the Kaiser method for this purpose. However, this method fails to take into account the fact that when dealing with random data (noise), it is possible to identify components with eigenvalues greater than one, or in other words, to select redundant components. We conclude that when selecting the main components, the classical mechanisms should be used with caution. The Parallel analysis method uses multiple data simulations to overcome the problem of random errors. This method assumes that the components of real data must have greater eigenvalues than the parallel components derived from simulated data which have the same sample size and design, variance and number of variables. A comparative analysis of the eigenvalues was performed by means of two methods: the Kaiser criterion and the parallel Horn analysis on the example of several data sets. The study shows that the method of parallel analysis produces more valid results with actual data sets. We believe that the main advantage of Parallel analysis is its ability to model the process of selecting the required number of main components by determining the point at which they cannot be distinguished from those generated by simulated noise.
Źródło:
Statistics in Transition new series; 2023, 24, 1; 199-212
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of roller bearing cages
Autorzy:
Kohar, R.
Krzysiak, Z.
Lukac, M.
Brumercik, F.
Powiązania:
https://bibliotekanauki.pl/articles/132167.pdf
Data publikacji:
2016
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
computer simulation
dynamic analysis
mathematical models
roller bearings
Opis:
The aim of this paper is to detail the creation of a roller bearing model with flexible body cages in the Adams program suite for subsequent dynamic analysis and to obtain information about kinematic and dynamic relationships of steel and plastic cages under various operating conditions. The bearing model was made to closely resemble its real-life counterpart, which allows us to estimate load conditions, dynamic conditions of individual bearing parts and interactions between them.
Źródło:
Advanced Technologies in Mechanics; 2016, 3, no. 2 (7); 2-11
2392-0327
Pojawia się w:
Advanced Technologies in Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The initial analysis of the aerodynamic characteristics of a 3D printed model of an aircraft
Autorzy:
Lusiak, T.
Babel, R.
Powiązania:
https://bibliotekanauki.pl/articles/246283.pdf
Data publikacji:
2018
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
air transport
simulation
wind tunnel
experimental analysis
gyroplane
Opis:
The aerodynamic research into models of an aircraft aims at creating the main characteristics of aerodynamic forces and moments and the aerodynamic characteristics of coefficients of aerodynamic forces and moments, based on real dimensions. The method of 3D printing was used to create a model of an aircraft. The model with the previously set printing parameters and commands for a 3D printer, in the right order, was imported into MakerBot Print. The final stage was printing the model. The printed components of the model of an aircraft were imperfect due to the incorrectly set printing parameters. The model with the previously set printing parameters and commands for a 3D printer, in the right order, was imported into MakerBot Print. The final stage was printing the model. The printed components of the model of an aircraft were imperfect due to the incorrectly set printing parameters. The printing parameters were corrected in the next printing sessions so the surfaces of the components were good enough and grinding was unnecessary. Some excess material was removed in each of the printed components, and the slots were cleaned. Then, the individual models were put together. The article describes the technique of creating a model of an aircraft to map its exact geometry for experimental wind tunnel research. 3D printing enables us to experimentally investigate a created geometry, in particular to investigate further prior to releasing an aircraft to service. The 3D model employs the model created in line with the previous CFD analysis.
Źródło:
Journal of KONES; 2018, 25, 4; 255-262
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Harmonic domain modelling of transformer core nonlinearities using the DIgSILENT powerfactory software
Autorzy:
Wiechowski, W.
Bak-Jensen, B.
Bak, C. L.
Lykkegaard, J.
Powiązania:
https://bibliotekanauki.pl/articles/262821.pdf
Data publikacji:
2008
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
autotransformers
harmonic analysis
nonlinearities
simulation software
transformer cores
Opis:
This paper demonstrates the results of implementation and verification of an already existing algorithm that allows for calculating saturation characteristics of singlephase power transformers. The algorithm was described for the first time in 1993. Now this algorithm has been implemented using the DIgSILENT Programming Language (DPL) as an external script in the harmonic domain calculations of a power system analysis tool PowerFactory [10]. The algorithm is verified by harmonic measurements on a single-phase power transformer. A theoretical analysis of the core nonlinearities phenomena in single and three-phase transformers is also presented. This analysis leads to the conclusion that the method can be applied for modelling nonlinearities of three-phase autotransformers.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2008, 14, 1; 3-11
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Network analysis for artificial intelligent micro-bearing systems
Autorzy:
Wierzcholski, K.
Łupicka, O.
Powiązania:
https://bibliotekanauki.pl/articles/243326.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
network analysis
choice process simulation
most proper scheme
Opis:
This paper presents the some implementation of network analysis in logical, topological form as a artificial intelligence component applied for determination of optimum system design regard to the micro-bearing operat mg parameters such as carrying load capacity, friction forces, friction coefficient and micro-bearing wear. Efficient functioning of slide micro-bearings systems require to choice the proper Journal shapes, bearing materials, roughness of bearing surfaces and many other features to which belongs capability to the processes control. Artificial intelligence of micro-bearing leads to the creating and indicating of the network logical models to describe most simple and most proper topological graphical schemes presenting the design of anticipated processes. Application of the logical network analysis into the micro-bearing HDD design is the subject-matter of this paper. Logical network analysis in graphical form as a mathematical implementation for intelligent micro-bearing mtmerical calculations is presented in this paper. Presented paper establish the scheme of calculation algorithm oj hydrodynamic pressure and carrying capacity changes in micro-bearings for various Journal shapes and for various geometries.
Źródło:
Journal of KONES; 2009, 16, 3; 489-495
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation studies into quayside transport and storage yard operations in container terminals
Autorzy:
Deja, M.
Dobrzyński, M.
Siemiątkowski, M. S.
Wiśniewska, A.
Powiązania:
https://bibliotekanauki.pl/articles/258686.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
container terminals
mechanical handling
simulation modelling
quantitative analysis
Opis:
The focus of the paper is in quayside transport and storage yard operations in container terminals. Relevant algorithms have been applied and a simulation model adopted. Evaluative criteria chosen for that model were: the total time of ship unloading and the truck utilization level. Recommendations for unloading in berth and yard areas were analysed in three different case studies. Results of simulations and deterministic model based analyses are included.
Źródło:
Polish Maritime Research; 2017, S 1; 46-52
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
FEM calculations in analysis of steel subsea water injection flowlines designing process
Autorzy:
Wodtke, M.
Olszewski, A.
Wójcikowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/259856.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
offshore engineering
water injection flowlines analysis
FEM simulation
Opis:
The article describes the result of theoretical research aimed at assessing the loads and operating conditions of a Coiled Tubing pipeline injecting water, suspended to the mining platform of Lotos Petrobaltic. For this purpose, appropriate calculation models have been developed using the Finite Element Method (FEM), taking into account the nature of the analyzed object and its loads. The analyzes were carried out for two pipes (previously operated and newly proposed) differing in geometrical and strength parameters. The research was carried out for selected directions of load on the pipeline (originating from sea waves) and various variants of attaching the suspended pipeline to the mining platform.
Źródło:
Polish Maritime Research; 2018, 3; 84-93
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
DC Large-Scale Simulation of Nonlinear Circuits on Parallel Processors
Autorzy:
Udave, D. E. C.
Ogrodzki, J.
de Anda, G. M. A.
Powiązania:
https://bibliotekanauki.pl/articles/226087.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
circuit simulation
parallel computation
DC analysis
circuit decomposition
Opis:
Newton-Raphson DC analysis of large-scale nonlinear circuits may be an extremely time consuming process even if sparse matrix techniques and bypassing of nonlinear models calculation are used. A slight decrease in the time required for this task may be enabled on multi-core, multithread computers if the calculation of the mathematical models for the nonlinear elements as well as the stamp management of the sparse matrix entries is managed through concurrent processes. In this paper it is shown how the numerical complexity of this problem (and thus its solution time) can be further reduced via the circuit decomposition and parallel solution of blocks taking as a departure point the Bordered-Block Diagonal (BBD) matrix structure. This BBD-parallel approach may give a considerable profit though it is strongly dependent on the system topology. This paper presents a theoretical foundation of the algorithm, its implementation, and numerical complexity analysis in virtue of practical measurements of matrix operations.
Źródło:
International Journal of Electronics and Telecommunications; 2012, 58, 3; 285-295
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza numeryczna właściwości numerycznych siatkowego pocisku wirującego
Numerical analysis of dynamic characteristics of spin deployed net round
Autorzy:
Mazur, P.
Kupidura, P.
Powiązania:
https://bibliotekanauki.pl/articles/236182.pdf
Data publikacji:
2009
Wydawca:
Wojskowy Instytut Techniczny Uzbrojenia
Tematy:
symulacja lotu
analiza numeryczna
flight simulation
numerical analysis
Opis:
W artykule przedstawiono wybrane założenia konstrukcyjne, krótki opis budowy, przyjętą metodykę i wyniki numerycznej symulacji lotu wirującego pocisku siatkowego do prototypowego naboju granatnikowego 40 x 46 mm SR. Nabój aktualnie znajduje się w fazie badań w Wojskowej Akademii Technicznej.
The main construction requirements, short technical specification and description of numerical method used for spin deployed net grenade flight simulation and some obtained results as well are included into this paper. The grenade, designed for prototype 40 x 46 mm SR grenade round, is currently being tested in Military University of Technology.
Źródło:
Problemy Techniki Uzbrojenia; 2009, R. 38, z. 109; 157-165
1230-3801
Pojawia się w:
Problemy Techniki Uzbrojenia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of influence of drive system configurations of a four wheelled robot on its mobility
Autorzy:
Trojnacki, M.
Powiązania:
https://bibliotekanauki.pl/articles/384552.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
mobile robot
mobility analysis
dynamics model
computer simulation
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2012, 6, 4; 65-70
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of tracked vehicle dynamics
Autorzy:
Kciuk, S.
Mężyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/246193.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
multibody
trucked vehicle
numerical simulation
dynamical analysis
suspension
Opis:
The paper presents the problem of modelling dynamics of motor vehicles in the convention of multi-segment systems. The assumptions used in modelling process arepresented and the characteristics of elastic - damping elements of tracked vehicle suspension system are determined. This paper presents the identified mass and the geometrical parameters of the vehicle, on the basis of these parameters in Virtual.Lab software environment the simulation model was developed. The model describes the elements of a tank that does not change their position relative to the reference coordinate system, they are: the turret, muzzle, body case, and other components such as: wheels, torsion shafts, damper levers and links. The tank tracks are omitted in the simulation model. The results of numerical simulations in the form of displacement courses of characteristic points of the hull and displacements of the wheels axles in an assumed reference coordinate system are also included. The simulation results were compared with experimental results obtained on the proving ground. The results of experimental measurements carried out on the tank range, were used to precise tune a mathematical model of the vehicle. The results of numerical simulations confirmed validity ofthe assumptions in the modelling process, since good agreement was obtained with results from experimental investigations. The developed models will be used to optimize the characteristics of vehicle suspension.
Źródło:
Journal of KONES; 2010, 17, 1; 223-232
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Failure simulation of Babar dam – Algeria and its impact on the valley downstream section
Autorzy:
Gaagai, Aissam
Boudoukha, Abderrahmane
Benaabidate, Lahcen
Powiązania:
https://bibliotekanauki.pl/articles/292897.pdf
Data publikacji:
2020
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
dam
dam failure
Hec-Ras
sensitivity analysis
simulation
Opis:
A failure analysis of Babar dam on the El Arab River was performed to highlight the impact of flood wave and velocities on the four villages downstream of the dam; Hella, Khérenne, Chebla and El Oueldja. The simulation of wave propagation along the El Arab River under several scenarios was performed by the hydraulic HEC-RAS model. This model is dedicated to the description of floods at the dam following a breach in the dike. The main factors considered in this simulation include the level of flood water, the flood hydrograph, and the typical scenario for this breach. The flood risk analysis revealed that the maximum of flood wave flow registered at the breach is (Qmax = 9253.02 m3∙s–1), and is beginning to mitigate downstream of the dam along the El Arab River where it reached at the last village with a low flow (Q = 1110.64 m3∙s–1). This simulation allowed drawing the risk map which showed the areas threatened by flood wave resulting from a total failure of the work, and consequently required a plan of security measures to moderate as much as possible the consequences of floods. A sensitivity analysis was conducted to approach the parameters of impact of the breach on the dam failure scenario. It was confirmed that these parameters as formulation time, breach width and side slope have a great influence on the dam failure scenario with the four adjustments (±20 and ±50).
Źródło:
Journal of Water and Land Development; 2020, 44; 75-89
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation and sensitivity analysis for biodiesel production in a reactive distillation column
Autorzy:
Agarwal, M.
Singh, K.
Chaurasia, S. P.
Powiązania:
https://bibliotekanauki.pl/articles/779118.pdf
Data publikacji:
2012
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
biodiesel
reactive distillation
modeling
simulation
transesterification
sensitivity analysis
Opis:
The conventional process for biodiesel production by transesterification is still expensive due to a need of high excess of alcohol required and its recovery by distillation. The use of a reactive distillation process can reduce the amount of alcohol in the feed stream as it works on a simultaneous reaction and separation. In the present study, a mathematical model has been developed for biodiesel production from triglycerides in a reactive distillation column, which has been validated with the reported data and CHEMCAD results. The effects of process parameters such as methanol to oil feed ratio, feed temperature, and reaction time have been investigated. The sensitivity analysis shows that yield of ester increases with methanol to oil ratio and number of stages, however, it decreases with fl ow rate. The MATLAB simulated results show that methanol to oil molar ratio of 5:1 produces 90% (by wt.) of methyl ester in a residence time of 4.7 minutes.
Źródło:
Polish Journal of Chemical Technology; 2012, 14, 3; 59-65
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automated root cause analysis of non-conformities with machine learning algorithms
Autorzy:
Mueller, T.
Greipel, J.
Weber, T.
Schmitt, R. H.
Powiązania:
https://bibliotekanauki.pl/articles/99625.pdf
Data publikacji:
2018
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
root cause analysis
machine learning
decision tree
simulation
Opis:
To detect root causes of non-conforming parts - parts outside the tolerance limits - in production processes a high level of expert knowledge is necessary. This results in high costs and a low flexibility in the choice of personnel to perform analyses. In modern production a vast amount of process data is available and machine learning algorithms exist which model processes empirically. Aim of this paper is to introduce a procedure for an automated root cause analysis based on machine learning algorithms to reduce the costs and the necessary expert knowledge. Therefore, a decision tree algorithm is chosen. A procedure for its application in an automated root cause analysis is presented and simulations to prove its applicability are conducted. In this paper influences affecting the success of detection are identified and simulated e.g. the necessary amount of data dependent on the amount of variables, the ratio between categories of non-conformities and OK parts as well as detectable root causes. The simulations are based on a regression model to determine the roughness of drilling holes. They prove the applicability of machine learning algorithms for an automated root cause analysis and indicate which influences have to be considered in real scenarios.
Źródło:
Journal of Machine Engineering; 2018, 18, 4; 60-72
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Economic aspects of component importance analysis for complex marine systems
Autorzy:
Chybowski, L.
Gawdzińska, K.
Powiązania:
https://bibliotekanauki.pl/articles/135038.pdf
Data publikacji:
2017
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
importance analysis
complex system
sensitivity analysis
marine system
economic aspects
computer simulation
Opis:
The paper presents the application of cost-based, component-importance measures for complex technical systems. A stern tube sealing system installed on a sea vessel was used as an example of a complex technical system. Selected statistics of a ship’s operation losses were calculated. Selected, known-importance measures were presented and the authors’ own approach to cost-based, component-importance analysis was shown. The following measures were discussed: the operation-interruption cost index, the maintenance potential, the simulation-based maintenance index, and maintenance and operational costs. A description of factors influencing the importance of the technical system components was provided.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2017, 51 (123); 59-65
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A new two-scroll 4-D hyperchaotic system with a unique saddle point equilibrium, its bifurcation analysis, circuit design and a control application to complete synchronization
Autorzy:
Vaidyanathan, Sundarapandian
Moroz, Irene M.
Sambas, Aceng
Powiązania:
https://bibliotekanauki.pl/articles/27312011.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
hyperchaos
hyperchaotic systems
bifurcation analysis
multi-stability analysis
synchronization
Multisim
circuit simulation
Opis:
In this work, we present new results for a two-scroll 4-D hyperchaotic system with a unique saddle point equilibrium at the origin. The bifurcation and multi-stability analysis for the new hyperchaotic system are discussed in detail. As a control application, we develop a feedback control based on integral sliding mode control (ISMC) for the complete synchronization of a pair of two-scroll hyperchaotic systems developed in this work. Numerical simulations using Matlab are provided to illustrate the hyperchaotic phase portraits, bifurcation diagrams and synchronization results. Finally, as an electronic application, we simulate the new hyperchaotic system using Multisim for real-world implementations.
Źródło:
Archives of Control Sciences; 2023, 33, 2; 277--298
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the Risk of Location the Quay for Large Steel Components Handling in Vicinity of the Fairway Using the Fast-Time Simulation Method
Autorzy:
Marcjan, K.
Gucma, L.
Powiązania:
https://bibliotekanauki.pl/articles/320713.pdf
Data publikacji:
2018
Wydawca:
Polskie Forum Nawigacyjne
Tematy:
risk of collision
Fast-Time-Simulation
safety of navigation
statistical analysis
ship manoeuvring simulation
Opis:
The paper presents the use of the Fast-Time navigational simulator to verify the location of designed elements of navigational infrastructure in vicinity of a high traffic fairway. The aim of the study is to perform the analysis of navigational safety in vicinity of newly constructed quay placed to the east of the island Ostrow Brdowski. The Quay is intended handling of large steel structures. The Fast-Time simulation is performed to evaluate the safety of the navigation passage through the fairway along the quay for the future use of vessels which length may exceed 260 m. This kind of simulation method has been implemented to make a statistical analysis based on a large amount of data, the collection of which would be very expensive and time consuming using a Real-Time simulator.
W artykule przedstawione zostanie wykorzystanie symulatora nawigacyjnego typu Fast-Time w celu weryfikacji lokalizacji projektowanego nabrzeża w pobliżu uczęszczanego toru wodnego. Celem opracowania jest wykonanie analizy nawigacyjnej dla nowobudowanego nabrzeża na wschodniej części wyspy Ostrów Brdowski przeznaczonego do załadunku wielkogabarytowych konstrukcji stalowych. Zaprezentowano ocenę bezpieczeństwa nawigacyjnego przejścia przez tor wodny prowadzący wzdłuż nabrzeża, dla przyszłościowych jednostek o długości 260 m, wykonana metodą symulacyjną Fast-Time. W badaniu wykorzystano model czasu przyspieszonego ze względu na dużą ilość danych (przejazdów) potrzebnych do wykonania analizy statystycznej, użycie symulatora czasu rzeczywistego do uzyskania wystarczającej ilości danych byłoby zbyt drogie i zbyt kosztowne w czasie.
Źródło:
Annual of Navigation; 2018, 25; 93-108
1640-8632
Pojawia się w:
Annual of Navigation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fatigue Life Predicting for Nitrided Steel - Finite Element Analysis
Autorzy:
Sawicki, J.
Siedlaczek, P.
Staszczyk, A.
Powiązania:
https://bibliotekanauki.pl/articles/355788.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
numerical simulation
nitriding
fatigue life
fatigue analysis
finite element
Opis:
Thermo-chemical treatments are known to increase the fatigue life of industrial parts. Due to the imprecise consideration of residual stresses in predicting the durability of components subjected to cyclic loading and their effect on the fatigue life, the authors developed a numerical model combining the influence of residual stresses with stresses caused by bending. The authors performed the numerical simulation with the use of Finite Element Method to analyse material behaviour during cyclic loading. The residual stress state developed during nitriding was introduced onto cross-section of the numerical specimen. The goal of this work was better understanding of the real conditions of the nitride steel fatigue processes and improving the knowledge about numerical predicting of the fatigue life for parts with residual stresses. The results of simulation were compared with plane bending fatigue tests. The presented method indicates the possibility of increasing the accuracy of the fatigue analysis of elements after surface treatment, increasing its certainty and the ability to perform better optimization of service life.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 921-927
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Validation studies of the simplified model of the missile with cumulative head
Autorzy:
Sybilski, K.
Panowicz, R.
Kołodziejczyk, D.
Niezgoda, T.
Powiązania:
https://bibliotekanauki.pl/articles/246839.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
RPG
simulation
FEM analysis
safety
slat armour
rod armour
Opis:
During ongoing conflicts around the world, some of the most dangerous threats are rocket-propelled grenades. They are light, easy to use and cheap, and their penetration reaches 900 mm of armoured RHA steel. Therefore, in many experimental and numerical laboratories there are researches of different, in aspect of shape, dimensions and used material, types of rod armours protecting against such a threat carried out. This kind of research must be confirmed in the last part of design by appropriate field tests. However, at the beginning of the design process, it is important to find a fast method of testing the developed solutions in a manner, which allows us to observe and measure as many process parameters as possible. One of such tests is research with the use of simplified models built in an appropriate scale. Small dimensions and simple construction result in the fact that the cost of manufacturing of models is much lower, and time is shorter. Tests on the simplified models are also possible to be carried out in laboratory conditions, what reduces the costs and makes the measurements of physical properties easier. The article describes experimental investigations of the impact of a simplified missile with a shape charge jet head model into a thick plate and steel rods. The construction of a missile, the used equipment and apparatus as well as the proceedings of the experiment are presented. The paper provides information about the structure of FE model and both initial and boundary conditions of the examined system. The results of numerical analysis are presented and compared with the results from experimental tests.
Źródło:
Journal of KONES; 2012, 19, 3; 415-420
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electromagnetically excited audible noise - evaluation and optimisation of electrical machines by numerical simulation
Autorzy:
Schlensok, C.
Schmülling, B.
Giet, M.
Hameyer, K.
Powiązania:
https://bibliotekanauki.pl/articles/262795.pdf
Data publikacji:
2006
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
numerical simulation
electrical machines
FEM
BEM
acoustics
structured analysis
Opis:
Disturbing vibrations and noise of electrical machines are gaining impact. Therefore, it is necessary to estimate the electromagnetic, structure-dynamical, and acoustic behavior of the machine during designing and before prototyping. An adequate tool is numerical simulation applying the Finite-Element Method (FEM) and the Boundary-Element Method (BEM) allowing for the structured analysis and evaluation of audible noise also caused by manufacturing tolerances. The methods developed and proved at the Institute of Electrical Machines (IEM) at RWTH Aachen University can be applied to any electromagnetic device in general.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2006, 12, 2; 121-128
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie metody symulacji dyskretnej do optymalizacji podejmowanych decyzji ekonomicznych
Application of discrete simulation for decisions of economic optimization
Autorzy:
Janiga-Ćmiel, Anna
Powiązania:
https://bibliotekanauki.pl/articles/593682.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Analiza jakości produkcji
Symulacja dyskretna
Discrete simulation
Production analysis
Opis:
Głównym celem artykułu jest zastosowanie metody symulacji dyskretnej do analizy wybranej produkcji. Omówiono technikę modelowania i symulacji dyskretnej zdarzeń, dotyczącą ich porządkowania według narzuconych przez badacza kryteriów.
The main aim of this paper is to present the discrete simulation methods for the analysis of the selected production. The theory of the construction and simulation of discrete events are discussed. In this study, we propose this methods where ordering process is determined on the basis of the criteria of the researcher.
Źródło:
Studia Ekonomiczne; 2016, 265; 16-25
2083-8611
Pojawia się w:
Studia Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
AGMEMOD MODEL – STRUCTURE AND APPLICATION FOR ANALYSIS AND SIMULATION OF POLISH AGRICULTURAL SECTOR
Autorzy:
Hamulczuk, Mariusz
Hertel, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/453061.pdf
Data publikacji:
2009
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Katedra Ekonometrii i Statystyki
Tematy:
partial equilibrium modeling
simulation
agricultural policy analysis
milk quota
Opis:
The aim of this paper was to present the AGMEMOD[1] model as an example of partial equilibrium model applied in the field of agricultural economics and its capacity to evaluate changes in the Common Agricultural Policy (CAP). The AGMEMOD model is an econometric, dynamic, multi-product, partial-equilibrium modelling system constructed within the 5th and 6th EU Framework Project. As an example of application of the model a quantitative assessment of the impact of the milk quotas abolition on the Polish dairy sector was displayed.
Źródło:
Metody Ilościowe w Badaniach Ekonomicznych; 2009, 10, 1; 88-98
2082-792X
Pojawia się w:
Metody Ilościowe w Badaniach Ekonomicznych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reliability based optimization of steel frames under seismic loading conditions using evolutionary computation
Niezawodnościowo zorientowana optymalizacja ram stalowych poddanych obciążeniom sejsmicznym za pomocą ewolucyjnej techniki obliczeniowej
Autorzy:
Papadrakakis, M.
Tsompanakis, Y.
Lagaros, N. D.
Friagiadakis, M.
Powiązania:
https://bibliotekanauki.pl/articles/281939.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
structural optimization
Monte Carlo simulation
reliability analysis
evolutionary computation
multi-modal response spectrum analysis
Opis:
Earthquake-resistant design of structures using probabilistic analysis and performance-based design criteria is an emerging field of structural enginering. These new analysis and design methodologies are aimed at improving the existing practice and design codes for better prediction of the structural performance. In this paper, a robust and efficient methodology is presented for performing reliability-based structural optimum design of steel frames under seismic loading. The optimization part is realised with evolution strategies, while the reliability analysis is carried out with the Monte Carlo simulation method icorporating the latin hypercube sampling technique for the reduction of the sample size. The probability of failure of the frame structures, in terms of interstorey drift limits, is determined via the multi-modal response spectrum analysis.
Konstruowanie budowli o zwiększonej odporności na trzęsienia ziemi poprzez wykorzystanie rachunku prawdopodobieństwa i kryteriów eksploatacyjnych jest nowa rozwijająca się dziedzina inżynierii konstrukcji. Nowa metodologia i procedury postępowania celują w udoskonalanie istniejących programów i pakietów obliczeniowych przewidujących zachowanie się danej budowli w zadanych warunkach. W pracy zaprezentowano sztywną i wydajną metodologię optymalizacji zorientowaną na niezawodność ram stalowych poddanych obciążeniom sejsmicznym. Optymalizację oparto na obliczeniach ewolucyjnych, natomiast analizę niezawodności zrealizowano metodą Monte-Carlo, w której do redukcji wymiarowości zagadnienia wykorzystano technikę LHS (Latin Hypercube Sampling). Prawdopodobieństwo uszkodzenia konstrukcji, w sensie przekroczenia granicznych przemieszczeń międzykondygnacyjnych, obliczono za pomocą wielomodalnej analizy widma odpowiedzi konstrukcji.
Źródło:
Journal of Theoretical and Applied Mechanics; 2004, 42, 3; 585-608
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic and Stress Analysis of a Locking Mechanism in the Ansys Workbench Software Environment
Autorzy:
Sapietová, Alžbeta
Novák, Pavol
Sága, Milan
Šulka, Peter
Sapieta, Milan
Powiązania:
https://bibliotekanauki.pl/articles/103266.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
simulation
sensitivity analysis
dynamic analysis
stress analysis
MSC
ADAMS
ANSYS
symulacja
analiza wrażliwości
analiza dynamiczna
analiza naprężeń
Opis:
This paper presents dynamic and stress analysis of a virtual prototype (VP) of a lock mechanism, which would lead to verification of its functionality in terms of kinematic, dynamic and strength parameters. The proposed modifications of input parameters of the technical equipment addressed were verified using the software environment of MSC. ADAMS and FEM software ANSYS Workbench.
Źródło:
Advances in Science and Technology. Research Journal; 2019, 13, 1; 23-28
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie analizy termicznej do symulacji zjawisk w procesach metalurgicznych
Application of thermal analysis to simulate the phenomena in metallurgical processes
Autorzy:
Stecko, J.
Różański, P.
Zalecki, W.
Powiązania:
https://bibliotekanauki.pl/articles/182445.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Metalurgii Żelaza im. Stanisława Staszica
Tematy:
thermal analysis
DTA
DSC
reduction
simulation
heat treatment
semi-industrial physical simulation
hot rolling
strip
bar
Opis:
W artykule przedstawiono przykłady wykorzystania analizy termicznej w badaniach surowców i technologii hutniczych z obszaru tematyki prac badawczych realizowanych w Zespole Procesów Surowcowych Instytutu Metalurgii Żelaza.
The paper presents the examples of application of thermal analysis in the research on raw materials and metallurgical technologies in the field of the research works carried out in the Primary Processing Group of the Institute for Ferrous Metallurgy.
Źródło:
Prace Instytutu Metalurgii Żelaza; 2012, T. 64, nr 1, 1; 161-168
0137-9941
Pojawia się w:
Prace Instytutu Metalurgii Żelaza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Towards an Optimal Motor Mounting Bracket Using Topology Optimization Combined with Sustainability and Manufacturing Cost Analysis
Autorzy:
Fassi, Hicham Fihri
Aniyou, Hadji
Powiązania:
https://bibliotekanauki.pl/articles/27324206.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
engine mount
topology optimization
numerical simulation
sustainability
manufacturing
costing analysis
Opis:
The engine is the most important component of a vehicle. It attaches to the main frame via the engine mounting bracket which supports weight and operating loads. The engine mount therefore plays a crucial role in the durability and comfort of the vehicle. This article contributes to the search for the most optimal model from the point of view of resistance, environmental impact, and manufacturing cost. This involves, on the one hand, optimizing the support by reducing its initial mass by 30%, and on the other hand, seeking suitable material and manufacturing process with the least environmental impact. To this end, topology optimization will be combined with an environmental assessment and a manufacturing cost analysis. Four materials will be tested and evaluated. Finally, a cost analysis will present a comparison between a conventional process and 3D printing.
Źródło:
Management and Production Engineering Review; 2023, 14, 4; 109--116
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of diagnostic utility of torque and rotational speed fluctuation of propulsion shaft
Autorzy:
Dereszewski, M.
Polanowski, S.
Charchalis, A.
Powiązania:
https://bibliotekanauki.pl/articles/247279.pdf
Data publikacji:
2011
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
marine diesel engine
diagnostics
failure simulation
torque and speed analysis
Opis:
In the paper has been presented the analysis of diagnostic utility of signals, deriving from torque (measured value is an instantaneous shaft's torsion angle, torque value is subsequently calculated basing on shaft's steel Kirhoff's modulus or Young's modulus values) and angular acceleration of the propulsion shaft. All measurements has been carried out using photo optic torque meter ETNP-10, which was installed at the propulsion shaft run by two-stroke low speed marine diesel engine. In order to distinguish diagnostic signals, measurements of healthy engine run and subsequently simulations of a failure by one cylinder cut-off (suspending of a fuel pump) were done. Analysis of torque, revolutionary speed, angular acceleration were and subsequently, in order to distinguish spectral attributes of above functions, fast Fourier transform of speed waveforms were carried out. Diagrams presented in the paper shows comparison of mentioned above signals' waveforms. The most significant influence of simulated combustion process deviation at a signal's variation was noticed when rotational speed and angular acceleration of the shaft were considered. Acquired results of research and measurements are to be a subject of further analysis in order to define representative symptoms and diagnostic values corresponding to propulsion system and engine failures.
Źródło:
Journal of KONES; 2011, 18, 4; 77-83
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wybrane obliczenia symulacyjne na użytek projektowania nożycowo-palcowych zespołów tnących
Selected simulation analysis for use in designing of shear-finger cutting sections
Autorzy:
Bochat, A.
Zastempowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/334050.pdf
Data publikacji:
2011
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Maszyn Rolniczych
Tematy:
obliczenia
symulacja
zespół tnący
projekt
simulation
analysis
cutting section
design
Opis:
W pracy przedstawiono autorski matematyczny model procesu cięcia roślin źdźbłowych. Przedstawiony model uwzględnia skomplikowaną, zmienną budowę morfologiczną źdźbła, a także oddziaływanie środowiska zewnętrznego podczas ścinania rośliny. W pracy przedstawiono także wybrane wyniki obliczeń symulacyjnych na modelu matematycznym. Dla potrzeb obliczeń symulacyjnych opracowano program komputerowy ŹDŹBŁO 1, który może posłużyć do optymalizacji konstrukcji zespołów tnących na etapie projektowania oraz generowania nowych rozwiązań konstrukcyjnych.
In the article, a new, developed by the authors mathematical model of the process of plant material cutting with use of a shear - finger cutting section, has been presented. Innovatory nature of this model involves a new approach to the plant material to be cut. Other, so far developed models do not take into account the stalk stiffness changes along its length, which in the opinion of the authors is a too big simplification. The computer program named ŹDŹBŁO 1 was performed for needs of the simulation analysis. This program can be applied at the stage of design of the shear-finger cutting section. It should be observed that these mechanisms are widely used in agricultural machines.machines.
Źródło:
Journal of Research and Applications in Agricultural Engineering; 2011, 56, 1; 6-10
1642-686X
2719-423X
Pojawia się w:
Journal of Research and Applications in Agricultural Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The use of computer simulations in the analysis of physical phenomena models
Autorzy:
Dziurdź, Jacek
Powiązania:
https://bibliotekanauki.pl/articles/127720.pdf
Data publikacji:
2019
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
dynamic models
simulation
signal analysis
modele dynamiczne
symulacja
analiza sygnałów
Opis:
Tests of the technical condition of machines sometimes involve the analysis of dynamic phenomena associated with their work. The simplest methods are based on basic measurements, e.g. effective velocities and body vibration accelerations as well as sound pressure levels recorded in close vicinity of the tested object. For analysis, more advanced techniques use signals recorded in a certain period of time representing the studied phenomena. The development of computer techniques has enabled a relatively convenient modelling of technical objects. A well-identified model allows to extend research on real objects to include comprehensive computer analyses, thanks to which we can reduce time-consuming measurements or perform analyses for excitations which are difficult to perform at a test stand. Another application of a model is to generate signals, on the basis of which we can choose parameters of analysis methods to increase the effectiveness of diagnosis or test new analysis and inference algorithms. Several presented examples were implemented in the Matlab Simulink environment. Because the presented methods are universal, they can be used to analyze any physical phenomena described with more or less complicated models.
Źródło:
Vibrations in Physical Systems; 2019, 30, 2; 1-8
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reliability analysis of a system subjected to two-state operation process
Autorzy:
Kuligowska, E.
Powiązania:
https://bibliotekanauki.pl/articles/358995.pdf
Data publikacji:
2013
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
reliability analysis
simulation methods
operation states
semi-Markov process
modeling
Opis:
The paper presents analytical and Monte Carlo simulation methods applied to the reliability evaluation of a system operating at two different operation states. A semi-Markov process is applied to construct the system operation model and its main characteristics are determined. Analytical linking of this operation model with the system reliability model is proposed to get a general reliability model of the system operating at two varying operation conditions and to find its reliability characteristics. The application of Monte Carlo simulation based on this general model to the reliability evaluation of this system is proposed as well. The results obtained from those two considered methods are evaluated.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2013, 36 (108) z. 1; 100-104
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation tests of dynamics of vibroisolated railway lines with wibroisolating system based on elastomer elements
Badania symulacyjne dynamiki wibroizolowanych linii kolejowych z układem wibroizolacyjnym na bazie elementów elastomerowych
Autorzy:
Bednarz, Jarosław
Targosz, Jan
Powiązania:
https://bibliotekanauki.pl/articles/311482.pdf
Data publikacji:
2019
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
simulation tests
vibroisolation
vibration analysis
badania symulacyjne
wibroizolacja
analiza drgań
Opis:
The problem of propagation of vibration waves caused by the movement of rail vehicles in the ground is extremely important from the point of view of environmental protection against negative effects of dynamic impacts caused by rail transport. Therefore, there is a need to develop new methods for analyzing dynamic phenomena related to rail vehicle traffic. One of the methods that can be used to evaluate dynamic interactions is modeling using finite elements. The article presents a dynamic analysis of the track structure model and the impact of the application of its vibroisolation system on the level of ground vibration amplitude associated with the propagation of vibration waves from the track. The application of the finite element method allows for the analysis of the behavior of engineering structures in variable operating conditions dependent primarily on the speed of movement of vehicles on the track. Such analysis includes the use of a number of physical values that can be used to assess the impact of vibration on any engineering object. These values include, above all, acceleration at any measuring point on the measurement cross-section from the track to the engineering construction, e.g. a residential or industrial building as well as displacement or stress, which are dependent on the speed of the rail vehicle. Comparison of these values with generally available criteria and standards allows at the stage of designing the engineering structure for appropriate modifications to the substructure construction to limit the amplitude of the vibrations transmitted to the environment. These modifications consist mainly of the use of an appropriate vibroisolation system in the form of, for example, slabs or mats laid in the rail layer or pads underneath. Correct execution of the simulation requires careful preparation of the numerical model as well as a series of input data. The input data relate mainly to accurate material data concerning both engineering structures (bridges, viaducts, tunnels), rolling stock and soil parameters. Such data allow to prepare a spectrum of forces loading the modelled section of the track. This approach to the design process is particularly important due to the inability to modify the track after built it.
Problem rozchodzenia się fal drganiowych powodowanych ruchem pojazdów szynowych w gruncie jest niezwykle istotny z punktu widzenia ochrony środowiska przed negatywnymi skutkami oddziaływaniami dynamicznych powodowanych przez transport szynowy. W związku z tym istnieje konieczność opracowania nowych metod analizy zjawisk dynamicznych związanych z ruchem pojazdów szynowych. Jedną z metod, którą można wykorzystać do oceny oddziaływań dynamicznych jest modelowanie z wykorzystaniem elementów skończonych. W artykule przedstawiono analizę dynamiczną modelu konstrukcji torowiska oraz wpływu zastosowania jego systemu wibroizolacji na poziom amplitudy drgań gruntu związanej z propagacją fal drganiowych od torowiska. Zastosowanie metody elementów skończonych pozwala na analizę zachowania się konstrukcji inżynierskich w zmiennych warunkach eksploatacyjnych zależnych przede wszystkim od prędkości ruchu pojazdów po torowisku. Analiza taka obejmuje użycie szeregu wartości fizycznych, które mogą służyć do oceny wpływu drgań na dowolny obiekt inżynierski. Do takich wielkości możemy zaliczyć przede wszystkim przyspieszenia w dowolnym punkcie pomiarowym na przekroju pomiarowym od torowiska do konstrukcji inżynierskiej np. budynku mieszkalnego czy przemysłowego jak również przemieszczenia lub naprężenia, które są zależne od prędkości pojazdu szynowego. Porównanie tych wartości z ogólnie dostępnymi kryteriami oraz standardami pozwala na etapie projektowania konstrukcji inżynierskiej na odpowiednie modyfikacje konstrukcji podtorzy celem ograniczenia wartości amplitudy drgań przekazywanych do środowiska. Modyfikacje te polegają głównie na zastosowaniu odpowiedniego układu wibroizolacji w postaci np. płyt lub mat układanych w warstwie torowiska lub podkładek podszynowych. Poprawne wykonanie symulacji wymaga dokładnego przygotowania modelu numerycznego jak i szeregu danych wejściowych. Dane wejściowe dotyczą przede wszystkim dokładnych danych materiałowych dotyczących zarówno konstrukcji inżynierskich (mosty, wiadukty, tunele), parametrów taboru jak i gruntu. Takie dane pozwalają przygotować widmo sił obciążających modelowany odcinek torowiska. Takie podejście do procesu projektowania jest szczególnie istotne ze względu na brak możliwości modyfikacji wybudowanego torowiska po zakończeniu prac budowlanych.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2019, 20, 1-2; 151-155
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improvement in ro-ro stern berthing modelled on a case study
Autorzy:
Perkovic, M.
Batista, M.
Vidmar, P.
Luin, B.
Powiązania:
https://bibliotekanauki.pl/articles/135160.pdf
Data publikacji:
2016
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
mooring analysis
buoy engineering
accident
ro-ro
windage
tramontana
simulation
Opis:
The high volume transported by ro-ro vessels has not come without a price. Accidents and incidents related to design – lack of bulkheads, instability, problems with cargo access doors, stowage, securing cargo and lifesaving appliances – are growing along with the size of the vessels themselves. One particular and recurrent problem is the degree of these giant box-like high riding vessels exposed to wind. Recently the effect of a tramontana – a fierce, sudden and short term regional wind – in the Port of Koper was to detach a moored ship, causing an accident. This paper will present a study of that accident, and through simulations and modelling determine an improvement that will allow berthing perpendicular to the stern ramp to function more securely.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2016, 45 (117); 134-142
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Symulacyjna analiza wpływu liczby i rozmieszczenia luk niesystematycznych na dokładność prognoz
Simulation analysis of influence of number and distribution of unsystematic gaps on the accuracy of forecasts
Autorzy:
Oesterreich, Maciej
Powiązania:
https://bibliotekanauki.pl/articles/425016.pdf
Data publikacji:
2015
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
forecasting of missing data
simulation methods
analysis of gaps distribution
Opis:
In this paper there was conducted a statistical analysis of the impact of the distribution of unsystematic gaps on the accouracy of inter- and extrapolative forecasts in the seasonal time series. In the analysis, as variable, there was used the average period of stay of tourists in accommodation establishments in the West Pomeranian Voivodeship in the years 2008-2013. In calculations there were used simulation methods to generate ten thousand sets of gaps for the three variants, differed in the number of gaps. For all the set and variants of gaps, there were estimated time series models with exponential trend and relatively-fixed seasonality. In the next step there were built inter- and extrapolative forecasts and calculated their relative errors (MAPE). In the analysis there were used R program and Statistica 10.
Źródło:
Econometrics. Ekonometria. Advances in Applied Data Analytics; 2015, 2 (48); 78-88
1507-3866
Pojawia się w:
Econometrics. Ekonometria. Advances in Applied Data Analytics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance evaluation of HEC-HMS model for continuous runoff simulation of Gilgel Gibe watershed, Southwest Ethiopia
Autorzy:
Fanta, Sewmehon Sisay
Feyissa, Tolera Abdissa
Powiązania:
https://bibliotekanauki.pl/articles/1844290.pdf
Data publikacji:
2021
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
calibration
Gilgel Gibe
HEC-HMS
runoff simulation
sensitivity analysis
validation
Opis:
Hydrological models are widely used for runoff simulation throughout the world. The objective of this study is to check the performance of the HEC-HMS model for continuous runoff simulation of Gilgel Gibe watershed. It includes sensitivity analysis, calibration, and validation. The model calibration was conducted with data from the year 1991 to 2002 and validated for the year 2003 to 2013 period using daily observed stream flow near the outlet of the watershed. To check the consistency of the model, both the calibration and validation periods were divided into two phases. The sensitivity analysis of parameters showed that curve number (CN) and wave travel time (K) were the most sensitive, whereas channel storage coefficient (x) and lag time (tlag) were moderately sensitive. The model performance measured using Nash–Sutcliff Efficiency (NSE), Percentage of Bias (PBIAS), correlation coefficient (R2), root mean square error (RMSE), and Percentage Error in Peak (PEP). The respective values were 0.795, 8.225%, 0.916, 27.105 m3∙s–1 and 7.789% during calibration, and 0.795, 23.015%, 0.916, 29.548 m3∙s–1 and –19.698% during validation. The result indicates that the HEC-HMS model well estimated the daily runoff and peak discharge of Gilgel Gibe watershed. Hence, the model is recommended for continuous runoff simulation of Gilgel Gibe watershed. The study will be helpful for efficient water resources and watershed management for Gilgel Gibe watershed. It can also be used as a reference or an input for any future hydrological investigations in the nearby un-gauged or poorly gauged watershed.
Źródło:
Journal of Water and Land Development; 2021, 50; 85-97
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Optimization of a Numerical Steel Foundry Simulation Through a Characterization of the Thermal Properties of the Materials
Autorzy:
Souêtre, Morgan
Vaucheret, Alexis
Jacquet, Philippe
Carton, Jean-François
Powiązania:
https://bibliotekanauki.pl/articles/2172386.pdf
Data publikacji:
2022
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
foundry simulation
low-alloyed steel
green sand
thermal analysis
CALPHAD
Opis:
In many foundries, numerical simulation is used to determine the origins of different defects as this tool allows the acceleration of the design process. However, the databases provided by different software do not seem to tally with the actual properties of the material. In fact, every foundry uses a different grade of steel and varying mixtures of sand. An evaluation of the impact of different material properties showed the importance of measuring every physical property to improve the database of the software. Following this, an experiment was conducted to evaluate the gap between numerical simulations and the results obtained through experimentation. This experiment, called thermal analysis, consists in measuring the solidification and cooling of a cylinder filled with liquid steel. After the calculation of the steel properties and a simulation with real experimental parameters, a comparison between each cooling curve was realized. This comparison shows that the calculated properties provide a simulated cooling curve which is closer to the experimental curve than the properties in the original database. We did not explore all of the metal properties in this study, but the modification of the sand properties was explored, together with the thermal conductivity of the steel and sand. These other measurements will be obtained in a future study.
Źródło:
Journal of Casting & Materials Engineering; 2022, 6, 4; 76--80
2543-9901
Pojawia się w:
Journal of Casting & Materials Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Fluidity of Al-Si Alloy: Computer Simulation of the Influence of Temperature, Composition, and Pouring Speed
Autorzy:
Futáš, P.
Petrík, J.
Pribulová, A.
Blaško, P.
Palfy, P.
Powiązania:
https://bibliotekanauki.pl/articles/351852.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Al-Si
fluidity
computer simulation
regression analysis
Monte Carlo method
Opis:
The purpose of this study is to identify relationships between the values of the fluidity obtained by computer simulation and by an experimental test in the horizontal three-channel mould designed in accordance with the Measurement Systems Analysis. Al-Si alloy was a model material. The factors affecting the fluidity varied in following ranges: Si content 5 wt.% – 12 wt.%, Fe content 0.15 wt.% – 0.3 wt. %, the pouring temperature 605°C-830°C, and the pouring speed 100 g · s-1 – 400 g · s-1. The software NovaFlow&Solid was used for simulations. The statistically significant difference between the value of fluidity calculated by the equation and obtained by experiment was not found. This design simplifies the calculation of the capability of the measurement process of the fluidity with full replacement of experiments by calculation, using regression equation.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 4; 1799-1804
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methodology for the Composite Tire Numerical Simulation Based on the Frequency Response Analysis
Autorzy:
Karpenko, Mykola
Skačkauskas, Paulius
Prentkovskis, Olegas
Powiązania:
https://bibliotekanauki.pl/articles/24200834.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
tire
composite
finite elements metod
frequency analysis
numerical simulation
optimization
Opis:
Reliability and maintenance analysis in transport focus on the main objective of accident and incident investigations that benefit to better understanding of the causes of accidents and prevention of them in the future. The conducted research presents theoretical and experimental research on composite pneumatic tire used in transport engineering. The approach of the numerical simulation sequence which is offered in this research facilitates engineers in efficient determination of the dynamic properties and behaviour of vehicle tire at design stage. The tire materials have been tested by employing piezoelectric micro-vibration tests and frequency analyses. The Finite Element Method used for numerical simulation in combination with experimental measurements based on optimization by material frequency response, was applied in modelling tire material behaviour avoiding problems of composite structure modelling. The obtained results indicate that the offered methodology can be used in numerical simulation of composite tire investigation and considering material viscos-elastic properties.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 2; art. no. 163289
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of impact load form on dynamic response of chock-shield support
Autorzy:
Meng, Zhaosheng
Ma, Chen
Xie, Yunyue
Powiązania:
https://bibliotekanauki.pl/articles/27312794.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
hydraulic support
dynamic load
reliability analysis
mechanical-hydraulic co-simulation
Opis:
Chock-shield support is usually used in undergroud coal mining to protect the roof. However, as the mining depth gets deeper, impact load that came from the roof becomes stronger and more frequent. This causes the support to bear a large number of dynamic loads, and reducing its reliability. To improve the support performance of the chock-shield support, the mixed-kinetic model was established using the mechanical-hydraulic co-simulation method. The load distribution law of the support joint under impact load form different stability forces, impact load amplitude, and impact frequency is discussed. The mechanical-hydraulic cooperative response of the chock-shield support are obtained. The results show that different joints show typical non-uniformity characteristic during the loading process. The proposed mechanical-hydraulic co-simulation method can more accurately obtain the dangerous points of hydraulic support reliability. The results of this study will help to improve the reliability of the chock-shield support.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 3; art. no. 168316
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modele symulacyjne zagadnień transportowych w programie Arena
The simulation models of transport problems solving with Arena software
Autorzy:
Sutowski, P.
Sutowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/316752.pdf
Data publikacji:
2017
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
model symulacyjny
analizy transportowe
problem transportowy
Arena
techniki symulacyjne
simulation model
transport analysis
transport problem
simulation techniques
Opis:
W artykule przedstawiono modele symulacyjne zdefiniowane za pomocą programu Arena firmy Rockwell Automation, Inc. Każdy z opisanych w pracy modeli posiada własną strukturę i odpowiada przyjętemu algorytmowi wyboru racjonalnego przydziału trasy transportowej. Kryterium wyboru najlepszego wariantu (i tym samym najskuteczniejszego modelu) był całkowity koszt transportu zamówionego towaru z 6 różnych magazynów hurtowni budowlanej. Przeprowadzona w artykule analiza wykazała przydatność zastosowania modeli komputerowych i przeprowadzania symulacji do rozwiązywania zagadnień transportowych.
The paper presents simulation models defined with Arena of Rockwell Automation, Inc. Each of the five models described in the article has its own structure and corresponds to the adopted algorithm to choose the rational allocation of transport routes. The criterion for choosing the best option (and thus the most effective model) was the total cost of transport of goods ordered from 6 different storage of wholesale building materials supplier. Carried out in the article analysis showed the usefulness of the use of computer modelling and simulation to solve transportation problems.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2017, 18, 7-8; 262-266
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinematic simulation and numerical analysis of the suspension system of light wheeled vehicle
Autorzy:
Różyło, P.
Powiązania:
https://bibliotekanauki.pl/articles/243731.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
finite element method
kinematic simulation
suspension
light wheeled vehicles
numerical analysis
Opis:
The paper presents the process of kinematic simulation and FEM numerical analysis of the suspension system of the light-wheeled vehicle. Fragment of the suspension system is a set of simple vibration damping mechanisms occurring in light-wheeled vehicles. The materials used for analysis is aluminum, steel and rubber characterized by properties hyperplastic. The suspension system has been subjected to the force generated from the substrate, resulting from the prevailing inequality terrain. Kinematic simulation made using CAD software enabled the mapping of the actual behaviour of the suspension with a simple steering mechanism, while passing at the characteristic curvilinear track. Numerical investigations have enabled the analysis of stress distribution in the structural elements while pointing out areas with the highest levels of stress reduced, designated by HMH hypothesis (Huber-Mises-Hencky). The FEM analysis used local and global density of the mesh through which highlighted the level of maximum stress concentration. Result of reduced stress distribution shown exactly on the complete form of the test model of a wheeled vehicle suspension. In the analysis of numerical models have been used elasto-plastic materials and hyperplastic available in the Abaqus. Calculations were carried out taking into account the issues of using geometrically nonlinear Newton-Raphson method.
Źródło:
Journal of KONES; 2014, 21, 1; 241-247
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity of the game control of ship in collision situations
Autorzy:
Lisowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/258832.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
marine transport
safety of navigation
game control
sensitivity analysis
computer simulation
Opis:
The paper introduces the application of the theory of deterministic sensitivity control systems for sensitivity analysis taking place in game control systems of moving objects, such as ships. The sensitivity of parametric model of game ship control process and game control in collision situations - sensitivity to changes in its parameters have been presented. First-order and k-th order sensitivity functions of parametric model of the process and game control are described. The structure of the game ship control system in collision situations and the mathematical model of game control process in the form of state equations are given. Characteristics of sensitivity functions of the model and game ship control process on the base of computer simulation in Matlab/Simulink software have been presented. At the end are given proposals regarding the use of sensitivity analysis to practical synthesis of computer-aided system navigator in potential collision situations.
Źródło:
Polish Maritime Research; 2015, 4; 27-33
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie, symulacja i analiza systemów w środowisku WebSphere Business Modeler
Modeling, simulation and analysis of systems in WebSphere Business Modeler environment
Autorzy:
Nowicki, T.
Powiązania:
https://bibliotekanauki.pl/articles/404280.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Symulacji Komputerowej
Tematy:
modelowanie
symulacja
symulator
analiza
WebSphere Business Modeler
modelling
simulation
simulator
analysis
Opis:
W pracy przedstawiono możliwości pracy analityka złożonych systemów w środowisku programowym WebSphere Business Modeler Advanced firmy IBM. Pokazano podstawowe elementy środowiska oraz sposób modelowania w nim procesów biznesowych. Podkreślono jego własności użytkowe, w tym wynikające ze stosowania wbudowanego w tym środowisku symulatora. Symulator pozwala badać własności dynamiczne funkcjonowania systemów. Zaprezentowane zostały zarówno zalety modelowania w środowisku WebSphere Business Modeler, jak i zaobserwowane pewne ograniczenia, z jakimi spotkać się może analityk funkcjonowania systemów.
In the paper possibilities of WebSphere Business Modeler environment for complex system analyst are presented. Fundamental elements of this software environment were shown as well as the way to business processes construction. Utility properties were underlined, specially properties connected with embedded event-driven simulator. The simulator allows investigating the dynamic properties of the systems functioning. It was presented both the advantages of modeling in WebSphere Business Modeler environment and some possible restrictions for systems analyst.
Źródło:
Symulacja w Badaniach i Rozwoju; 2011, 2, 1; 23-36
2081-6154
Pojawia się w:
Symulacja w Badaniach i Rozwoju
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selected aspects of simulation of multi - module mechanisms with the use of multibody method
Autorzy:
Krasoń, W.
Kozłowski, R.
Derewońko, A.
Golczak, K.
Powiązania:
https://bibliotekanauki.pl/articles/247966.pdf
Data publikacji:
2012
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
bridges
simulation of multi-component mechanism
rigid models
multibody numerical analysis
Opis:
The paper presents numerical analysis of a single segment of a floating bridge built in the form of a metal cassette with a movable bottom. An internal elastic container - a pontoon filled with the air was fixed in the cassette [4]. It enables a fluent change of displacement of a single segment and of a floating ribbon assembled from segments. A multibody analysis of cooperation of the cassette in the process of filling the pontoon and opening the cassette was discussed. Numerical analysis of a single cassette presented in the paper constitutes a part of tests including stand tests. The single floating cassette has a typical shelled construction consists of a tight deck, a pneumatic chamber closed with a reinforced movable bottom and sets of fastenings together with a mechanism of bottom opening. Each cassette is equipped with a highly resistant elastic or semi-elastic cushion hereinafter called a pontoon. The movement of the bottom and the process of opening the cassette module with a pneumatic air cushion realized under an influence of pressure of the compressed air. As a result of uneven filling the individual chamber of the pontoon with the air or their uneven emptying in the process of closing the cassette, there can occur the asymmetry of displacements of the bottom resulted even in seizing of telescopic mechanisms. In the paper were considered the cases of symmetrical and asymmetrical movement of the bottom corresponding to symmetrical and unsymmetrical pull out of the telescopic mechanism modules. Dynamical analysis of movement of cooperating subsystems of the floating cassette was carried out with the use of MSC.Adams code [5, 8].
Źródło:
Journal of KONES; 2012, 19, 1; 207-214
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Komputerowa symulacja zmienności rat długoterminowych kredytów w PLN i CHF zaciągniętych w latach 2004-2008
Computer simulation of payments volatility for longterm loans in PLN and CHF drawn in 2004-2008
Autorzy:
Twardochleb, Michał
Powiązania:
https://bibliotekanauki.pl/articles/432279.pdf
Data publikacji:
2015
Wydawca:
Wydawnictwo Uniwersytetu Ekonomicznego we Wrocławiu
Tematy:
long-term loans
foreign exchange risk
computer simulation
financial risk analysis
Opis:
This paper presents the results of using proprietary simulation software for the analysis of the financial risk associated with long-term taking loans in domestic and foreign currency. The study was conducted for loans in PLN and CHF incurred in different periods characterized by a different situation on the financial markets (significantly different currency exchange rates or interest rates, another entry in the „economic cycle”). The theoretical part of the paper describes basic concepts in long-term loans, and also shows the major assumptions for analyzing financial risks arising from incurring long-term obligations in domestic or foreign currency. In the practical part the assumptions of simulation of volatility of future fixed repayment level for loans taken out in PLN or CHF between 2004 and 2008 were described. The results of simulation along with the calculation of the total amount paid in future periods for analyzed variants of credit were also presented.
Źródło:
Informatyka Ekonomiczna; 2015, 2(36); 50-59
1507-3858
Pojawia się w:
Informatyka Ekonomiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid methodology using balancing optimization and vibration analysis to suppress vibrations in a double crank-rocker engine
Autorzy:
Albaghdadi, Anwr M.
Baharom, Masri
Sulaiman, Shaharin
Powiązania:
https://bibliotekanauki.pl/articles/2057975.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
balancing optimization
vibration analysis
double crank rocker engine
mathematical modelling
simulation
Opis:
This study aims to present mathematical modelling to evaluate and analyze double crankrocker engine performance. The study suggests the use of two methods to reduce system vibration through balancing optimization and vibrational analysis. The combination of both methods acts as a verification method; besides it can be used as a tool for further system design enhancement and condition monitoring. The derived mathematical model is then used for balancing optimization to identify system shaking forces and moments, while variable speed is considered as an added parameter to evolve the optimization process. This factor shows better enhancement in reducing system shaking forces and moments compared to constant speed balancing method. Next, the system characteristics were concluded in terms of mode shapes and natural frequencies using modal and frequency response analysis, which give clear clue for secure system operational ground. Finally, the reduction in system vibrations was translated into engine’s centre of mass velocity, which evaluates balancing process effectiveness and indicate if further enhancement should be conducted.
Źródło:
Eksploatacja i Niezawodność; 2022, 24, 1; 53--61
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Critical situations and human resources in discrete transportation systems analysis
Autorzy:
Walkowiak, T.
Mazurkiewicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/2069570.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
discrete transportation system
system dependability
critical situations analysis
Monte-Carlo simulation
Opis:
The paper presents an approach to critical situations analysis related to discrete transportation systems (DTS). The critical situation is understood as sudden shortage of some system recourses resulting in the transportation system performance degradation. The analysis is realized based on availability calculation of DTS. The system is described by the formal model, which includes reliability and functional parameters of DTS as well as human resources – drivers and management system. The availability and average availability of the system, defined in a functional way, is discussed as a function of different essential parameters of DTS. The proposed analysis is based on the modelling and simulating of the system behaviour using Monte-Carlo approach. The paper presents some exemplar systems – based on real Polish Post DTS – modelling and results.
Źródło:
Journal of Polish Safety and Reliability Association; 2011, 2, 1; 205--216
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genetic algorithms-aided reliability analysis
Autorzy:
Harnpornchai, N.
Powiązania:
https://bibliotekanauki.pl/articles/2069699.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
genetic algorithms
reliability analysis
simulation methods
complex systems
multiple failure modes
Opis:
A hybrid procedure of Genetic Algorithms (GAs) and reliability analysis is described, discussed, and summarized. The procedure is specifically referred to as a Genetic Algorithms-aided (GAs-aided) reliability analysis. Two classes of GAs, namely simple GAs and multimodal GAs, are introduced to solve a number of important problems in reliability analysis. The problems cover the determination of Point of Maximum Likelihood in failure domain (PML), the computation of failure probability using the GAs-determined PML, and the determination of multiple design points. The MCS-based method using the GAs-determined PML is specifically implemented in the so-called an Importance Sampling around PML (ISPML). The application of GAs to each respective problem is then demonstrated via numerical examples in order to clarify the procedures. With an aid from GAs, reliability analysis is possible even if there is no information about the geometry or landscape of limit state surfaces and the total number of crucial likelihood points. In addition, GAs significantly improve the computational efficiency and realize the analysis of rare events under constrained computational resources. The implementation of GAs to reliability analysis for building up the hybrid procedure is readily because of their algorithmic simplicity.
Źródło:
Journal of Polish Safety and Reliability Association; 2009, 1; 145--156
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strength analysis of experimental crane, using proliftor 250 rope winch as an excitation of a girder
Autorzy:
Haniszewski, T.
Powiązania:
https://bibliotekanauki.pl/articles/374181.pdf
Data publikacji:
2018
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
simulation
crane
dynamics
FE analysis
symulacja
dźwig
dynamika
analiza elementów skończonych
Opis:
The article presents the research carried out on the experimental construction of a crane, where a hoist with an AC motor without a motor control system was used as an excitation signal for the girder. The purpose of the described research is to determine the relationship between the values of the dynamic surplus factor when lifting the load with the loose rope in the initial phase of lifting and the distance of the hoist from the supporting structure. The data was obtained based on the force tests in a steel wire rope and subsequent determination of the values of stresses and deflections accompanying the selected test cases for different positions of the vibration inductor using the FE method.
Źródło:
Transport Problems; 2018, 13, 3; 131-142
1896-0596
2300-861X
Pojawia się w:
Transport Problems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interactive gaming as a support for system dynamics learning with the use of Vensim
Interaktywne gry programu Vensim jako wsparcie procesu uczenia się w dynamice systemowej
Autorzy:
Kasperska, E.
Bajon, T.
Marjasz, R.
Powiązania:
https://bibliotekanauki.pl/articles/87284.pdf
Data publikacji:
2015
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
symulacja
analiza wrażliwości
optymalizacja
kalibracja
gra symulacyjna
gra interaktywna
simulation
sensitivity analysis
optimization
calibration
simulation game
interactive game
Opis:
This article presents the process of learning with the use of interactive gaming described on “Accidental Adversaries” archetype model, thus providing a new method of research than can be conducted on vast number of SD models. Authors selected an already well researched archetype to show a different approach in the process of model optimization. This gives the opportunity to share the knowledge about the possibilities of practical application of interactive gaming.
W artykule opisano proces uczenia się z wykorzystaniem interaktywnych gier przedstawiony na archetypie „Przypadkowi przeciwnicy”, pokazując w ten sposób nową metodę badania, która może być zastosowana w ogromnej liczbie modeli dynamiki systemowej. Autorzy wybrali dokładnie zbadany i opisany w literaturze archetyp, aby zilustrować nowe podejście do procesu optymalizacji modelu. Przykład prezentuje nowe możliwości praktycznego zastosowania interaktywnych gier symulacyjnych.
Źródło:
Zeszyty Naukowe. Matematyka Stosowana / Politechnika Śląska; 2015, 5; 99-110
2084-073X
Pojawia się w:
Zeszyty Naukowe. Matematyka Stosowana / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the optode array representation using optical properties at systole and diastole
Autorzy:
Jumadi, N A
Beng, G K
Mohd-Ali, M. A.
Zahedi, E
Powiązania:
https://bibliotekanauki.pl/articles/173805.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical simulation
optical properties
optode array
semi-infinite tissue layer
statistical
analysis
Opis:
The necessity to develop an optode array in order to probe the fetus oxygenation noninvasively regardless of the fetus position has been highlighted in previous literature. In this paper, a series of optical simulations are carried out to determine the best representation of optode array by using optical properties at systolic and diastolic states. The selection is based on the highest flux values accumulated at respective detectors. To accomplish the objective, a homogenous three-layer semi-infinite tissue model is implemented to represent the pregnant woman model. The geometry of the model as well as Monte Carlo simulation are carried out using commercial software, whereas the optical properties related to systolic and diastolic states are defined for all wavelengths. A statistical noise analysis is also introduced in order to find a sufficient number of rays to be launched into the optical tissue system.
Źródło:
Optica Applicata; 2013, 43, 4; 747-759
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Usage of modal test in verification of numerical model
Autorzy:
Więckowski, J.
Odyjas, P.
Powiązania:
https://bibliotekanauki.pl/articles/1190011.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
analiza modalna
analiza numeryczna
weryfikacja danych
modal analysis
fans vibrations
numerical simulation
Opis:
Tuning of the numerical model is very important step during designing process. Correctly tuned model ensures proper evaluation of dynamic characteristics of vibrating object. This paper presets comparison of experimental modal analysis and theoretical numerical modal test of axial fan casing. Thanks to properly tuned model, it was possible to receive results of the numerical simulations similar to real test.
Źródło:
Interdisciplinary Journal of Engineering Sciences; 2016, 4, 1; 42--44
2300-5874
Pojawia się w:
Interdisciplinary Journal of Engineering Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical determination of materials characteristics for the needs of simulation and analysis of stalk cutting processes
Numeryczne wyznaczanie charakterystyki materiałowej na potrzeby symulacji i analizy procesu cięcia materiałów źdźbłowych i łodygowych
Autorzy:
Kukiełka, K.
Patyk, R.
Kukiełka, L.
Bohdal, Ł.
Bartosik, P.
Powiązania:
https://bibliotekanauki.pl/articles/337353.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Maszyn Rolniczych
Tematy:
plant
stalk
stem
cutting
simulation
analysis
roślina
źdźbło
łodyga
cięcie
symulacja
analiza
Opis:
The aim of this work is to develop a numerical application to determine the materials characteristics and to simulate the phenomena of cutting process by a single stalks and a few stalks as well as to present the possibilities of its application for simulation of the cutting process under real conditions - occurring in cutting assemblies of typical agricultural machinery. An example of use of this application to the modelling of cutting process of stalks in the cutting system of the harvester Bizon is presented. The next stage will be to develop a methodology to enable better design of the knife units used in a variety of agricultural and forestry machinery and their optimization.
Celem niniejszej pracy jest opracowanie aplikacji numerycznej do wyznaczania mechanicznych charakterystyk materiałowych i symulacji zjawisk podczas procesu cięcia pojedynczego źdźbła oraz kilku źdźbeł oraz przedstawienie możliwości jej zastosowania do symulacji procesu cięcia w warunkach rzeczywistych – występujących w zespołach tnących typowych maszyn rolniczych. Podano przykład zastosowania tej aplikacji do modelowania procesu cięcia źdźbła w nożycowym zespole tnącym kombajnu zbożowego Bizon. Dalszym etapem będzie opracowanie metodyki umożliwiającej lepsze projektowanie zespołów tnących stosowanych w różnych maszynach rolniczych i leśnych oraz ich optymalizacja.
Źródło:
Journal of Research and Applications in Agricultural Engineering; 2014, 59, 1; 72-76
1642-686X
2719-423X
Pojawia się w:
Journal of Research and Applications in Agricultural Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Intelligent System in the Context of Business Process Modelling
Autorzy:
Yaremko, Svetlana A.
Kuzmina, Elena M.
Savina, Nataliia B.
Gromaszek, Konrad
Yeraliyeva, Bakhyt
Borankulova, Gauhar
Powiązania:
https://bibliotekanauki.pl/articles/1844622.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
business process
automation
simulation modelling
intelligent system
expert system
intelligence analysis
forecasting
Opis:
The article deals with the features and characteristics of intelligent systems for modelling business processes. Their classification was made and criteria for comparison were developed. According to the comparative analysis of existing expert systems for intelligent analysis, a reasonable choice of system for modelling business processes of a particular enterprise has been carried out. In general, it was found that the introduction of intelligent systems for modelling business processes of the enterprise and forecasting its activities for future allows management of the company to obtain relevant and necessary information for the adoption of effective management decisions and the development of a strategic plan.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 2; 163-168
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of adaptive simulation methods in reliability analysis
Zastosowanie adaptacyjnych metod symulacyjnych w analizie niezawodności
Autorzy:
Kolanek, K.
Jedno, S.
Powiązania:
https://bibliotekanauki.pl/articles/156843.pdf
Data publikacji:
2007
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
analiza niezawodności
symulacja
metoda Monte Carlo
reliability analysis
simulation
Monte Carlo method
Opis:
The cross-entropy method is a new approach to estimate rare event probabilities by Monte Carlo simulation. Application of this method for structural reliability analysis is presented. The efficiency of the approach is tested on some benchmark problems typical for reliability analysis.
Metoda wzajemnej entropii (ang. cross-entropy) jest nową modyfikacją metod Monte Carlo służącą do oszacowania prawdopodobieństwa rzadkich zdarzeń. W pracy przedstawiono zastosowanie tej metody do rozwiązania zagadnienia analizy niezawodności. Jej efektywność jest oceniona na przykładach charakteryzujących się trudnościami typowymi w analizie niezawodności.
Źródło:
Pomiary Automatyka Kontrola; 2007, R. 53, nr 8, 8; 29-32
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of the availability of resources, the allocation of buffers and number of workers on the effectiveness of an assembly manufacturing system
Autorzy:
Kłos, S.
Trebuna, P.
Powiązania:
https://bibliotekanauki.pl/articles/407452.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
computer simulation
availability of resources
buffer allocation
throughput analysis
work-in-progress
Opis:
This paper proposes the application of computer simulation methods in order to analyse the availability of resources, buffers and the impact of the allocation of workers on the throughput and work-in-progress of a manufacturing system. The simulation model of the production system is based on an existing example of a manufacturing company in the automotive industry. The manufacturing system includes both machining and assembly operations. Simulation experiments were conducted vis-`a-vis the availability of the different manufacturing resources, the various allocations of buffer capacities and the number of employees. The production system consists of three manufacturing cells – each cell including two CNC machines – and two assembly stations. The parts produced by the manufacturing cells are stored in buffers and transferred to the assembly stations. Workers are allocated to the manufacturing cells and assembly stations, but the number of workers may be less than number of workplaces and are thus termed ‘multi-workstations’. Using computer simulation methods, the impact of the availability of resources, the number of employees and of the allocation of buffer capacity on the throughput and work-in-progress of the manufacturing system is analysed. The results of the research are used to improve the effectiveness of manufacturing systems using a decision support system and the proper control of resources. Literature analysis shows that the study of the impact of buffer capacities, availability of resources and the number of employees on assembly manufacturing system performance have not been carried out so far.
Źródło:
Management and Production Engineering Review; 2017, 8, 3; 40-49
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative SWOT analysis of virtual reality and augmented reality ship passenger evacuation technologies
Autorzy:
Vukelic, Goran
Vizentin, Goran
Peric-Hadzic, Ana
Powiązania:
https://bibliotekanauki.pl/articles/2175548.pdf
Data publikacji:
2021
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
virtual reality
augmented reality
ship evacuation
evacuation simulation
SWOT analysis
passenger evacuation
Opis:
The purpose of this paper was to assess the possibility of using modern technologies, virtual reality (VR) and augmented reality (AR), to study the evacuation of passengers from ships. The evacuation of passengers from ships is usually studied from post-accident reports, laboratory or field experiments, and/or numerical modelling. Nowadays, with the rapid development of computer resources and wearable technology, evacuation can also be studied using VR or AR. The methods used in this paper for such assessments included a literature review (tools like Web of Science, Scopus, and Google Scholar indexing platforms) and comparative strengths, weaknesses, opportunities, threats (SWOT) analysis. The results demonstrated the great potential for the implementation of VR and AR technologies within the shipping industry, similar to how they have already found applications in the research of pedestrian evacuation from buildings or open spaces. Finally, recommendations for their use in ship passenger evacuation are presented.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2021, 68 (140); 99-107
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Slurry shield tunneling in soft ground. Comparison between field data and 3D numerical simulation
Autorzy:
Beghoul, Mohammed
Demagh, Rafik
Powiązania:
https://bibliotekanauki.pl/articles/178799.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
shield tunnelling
soil-structure interaction
3D numerical simulation
back analysis
settlement
Opis:
In urban areas, the control of ground surface settlement is an important issue during shield tunnel-boring machine (TBM) tunneling. These ground movements are affected by many machine control parameters. In this article, a finite difference (FD) model is developed using Itasca FLAC-3D to numerically simulate the whole process of shield TBM tunneling. The model simulates important components of the mechanized excavation process including slurry pressure on the excavation face, shield conicity, installation of segmental lining, grout injection in the annular void, and grout consolidation. The analysis results from the proposed method are compared and discussed in terms of ground movements (both vertical and horizontal) with field measurements data. The results reveal that the proposed 3D simulation is sufficient and can reasonably reproduce all the operations achieved by the TBM. In fact, the results show that the TBM parameters can be controlled to have acceptable levels of surface settlement. In particular, it seems that moderate face pressure can reduce ground movement significantly and, most importantly, can prevent the occurrence of face-expected instability when the shield crosses very weak soil layers. The shield conicity has also an important effect on ground surface settlement, which can be partly compensated by the grout pressure during tail grouting. Finally, the injection pressure at the rear of the shield significantly reduces the vertical displacements at the crown of the tunnel and, therefore, reduces the settlement at the ground surface.
Źródło:
Studia Geotechnica et Mechanica; 2019, 41, 3; 115-128
0137-6365
2083-831X
Pojawia się w:
Studia Geotechnica et Mechanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of negative effects of a coach running with the wheel-flat on a track by means of simulation computations
Autorzy:
Dižo, J.
Blatnický, M.
Steišūnas, S.
Powiązania:
https://bibliotekanauki.pl/articles/328430.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
coach
wheel flat
simulation computations
dynamic analysis
koło
obliczenia symulacyjne
analiza dynamiczna
Opis:
The objective of this paper is focused on the computer modelling and dynamic simulation of a coach with damaged wheel and the assessment of these negative effects on a track. The article is composed of two parts. Firstly, problems about the operation of rolling stocks with damaged wheels are described. There are also mentioned diagnostic systems installed on a track for detection and assessment their negative impacts on a track. The second part of the article is dedicated to computer modelling of a coach running on a railway track with the damaged wheel, in this case with the wheel-flat. For these purposes the virtual model of a coach were created. After simulations of its running there were performed analyses needed for the evaluation of its negative impacts on a railway track.
Źródło:
Diagnostyka; 2017, 18, 3; 31-37
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Odd log-logistic generalised Lindley distribution with properties and applications
Autorzy:
Ranjbar, Vahid
Eftekharian, Abbas
Kharazmi, Omid
Alizadeh, Morad
Powiązania:
https://bibliotekanauki.pl/articles/18707217.pdf
Data publikacji:
2023-09-08
Wydawca:
Główny Urząd Statystyczny
Tematy:
Lindley distribution
odd log-logistic generalised family
moments
Bayesian analysis
simulation study
Opis:
In this paper, a new three-parameter lifetime model, called the odd log-logistic generalised Lindley distribution, is introduced. Some structural properties of the new distribution including ordinary and incomplete moments, quantile and generating functions and order statistics are obtained. The new density function can be expressed as a linear mixture of exponentiated Lindley densities. Different methods are discussed to estimate the model parameters and a simulation study is carried out to show the performance of the new distribution. The importance and flexibility of the new model are also illustrated empirically by means of two real data sets. Finally, Bayesian analysis and Gibbs sampling are performed based on the two real data sets.
Źródło:
Statistics in Transition new series; 2023, 24, 4; 71-92
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative Analysis of the Production Process of a Flange-Type Product by the Hybrid and Traditional Method with the Use of Simulation Methods
Autorzy:
Terelak-Tymczyna, Agnieszka
Bachtiak-Radka, Emilia
Jardzioch, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2067547.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
machining
hybrid machining
VSM
SLM
process simulation
cost of the production
energy analysis
Opis:
In the era of Industry 4.0, the digitization of production processes is one of the important elements contributing to the reduction of uncertainty related to the implementation of new production methods. The worldwide epidemic situation and its constraints have resulted in supply chain continuity problems. These problems make enterprises look for the possibility of producing products that they need at the moment and which they cannot obtain from the market. In special cases, this may also apply to spare parts necessary to maintain the continuity of production. The main reason for research on comparing production processes is meeting the challenges related to the pandemic situation and problems in maintaining timeliness, flexibility, and continuity of the supply chain. The first stage of the research was to visualize the course of the process and determine the lead times for both production methods. For further analysis, a digital process model was used to compare the hybrid and the classical method to check the viability of the interchangeability of methods for the production process of the flange part. The interchangeability of production methods was dictated by problems related to the supply of components for the execution of orders. The article simulates the model for unit and small-lot production in batches of 10 and 100 pieces, considering such aspects as: order completion time, energy consumption of the process, production costs, taking into account the classic and hybrid methods. The conducted research was aimed at determining the profitability of the production of flange-type products by means of classical processing and hybrid and checking the interchangeability of production methods in accordance with quality requirements as well as reducing uncertainty with the implementation of new production systems in changing market conditions. The simulations show that the use of hybrid production is recommended for unit production. In the case of small-lot production, already with 10 items, production in the traditional process is 21% cheaper, and for the production of 100 items, the cost of traditional production is reduced by 33% compared to hybrid production.
Źródło:
Advances in Science and Technology. Research Journal; 2022, 16, 1; 231--242
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity analysis of steering system model
Autorzy:
Żardecki, D.
Powiązania:
https://bibliotekanauki.pl/articles/242406.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
car
steering system
piecewise linear model
simulation
sensitivity analysis
friction
freeplay
stick-slip
Opis:
The method of sensitivity analysis of mathematical model with strong non-linear characteristics is discussed in the paper. This model focuses on friction, as well as freeplay dynamics in a car steering system including stick-slip fenomena. Because of strong nonlinearities of the model, its sensitivity indexes can not be counted by classic sensitivity variation equations and classic mathematical analysis of smooth functions.  Fortunately,   nonlinear characteristics are described with using special piecewise - linear luz(...) and tar(...) projections. They have an original mathematical apparatus which secures parametrically made simplifications and enough regularity of the model (some details of analytical transformations are shown). Thanks to luz(...) and tar(...) projections the continuity of sensitivity indexes is secured but of course, the calculation of sensitivity indexes has to base on comparative simulation investigations. The paper presents example results of simulations of the steering system action (including stick-slip processes) for different values of friction as well as freeplay parameters (kinetic and static friction in king-pins, backlash in a steering gear). These simulations concern combined open road tests of a passenger car according to the ISO requirements (ISO 7401 - the ramp input on the steering wheel, then ISO 4138 - circular steady state motion, and finally the steering wheel released, all with a constant speed 80 km/h).
Źródło:
Journal of KONES; 2009, 16, 1; 571-581
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fault mode analysis and reliability optimization design of a mechanical interface based on cylindrical cam mechanisms
Autorzy:
Li, Jian-Hao
Liu, Zhi-Jie
Wang, Da-Peng
Tian, Yun
Zhao, Yu-Chong
Powiązania:
https://bibliotekanauki.pl/articles/1841922.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
mechanical interface
fault mode analysis
Monte Carlo simulation
reliability design
cylindrical cam mechanism
Opis:
The mechanical interface has the characteristics of low shock and vibration, and is emphasized in the aerospace and ocean engineering fields. In this paper, a mechanical interface based on coupled cylindrical cam mechanisms is designed. It can achieve the expected functions, but there exist faults in some times. The fault modes and causes of the interface are firstly analyzed. Then a design approach based on Monte Carlo simulation is presented for analyzing and optimizing its reliability. According to the fault modes, the performance functions of the interface are established for obtaining the optimal scheme. A case is given to illustrate the proposed method. The simulation results and the prototype experiments prove that the optimization scheme effectively improves the reliability of the interface, and has better performance than the original one.
Źródło:
Eksploatacja i Niezawodność; 2020, 22, 4; 715-723
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Implementing Monte Carlo simulation model for revenue forecasting under the impact of risk and uncertainty
Autorzy:
Hussain, Zahid
Powiązania:
https://bibliotekanauki.pl/articles/406901.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
risk analysis
management
Monte Carlo
simulation model
crystal ball package software
production uncertainty
Opis:
In the existent world of continuous production systems, strong attention has been waged to anonymous risk that probably generates significant apprehension. The forecast for net present value is extremely important for any production plant. The objective of this paper is to implement Monte Carlo simulation technique for perceiving the impact of risk and uncertainty in prediction and forecasting company’s profitability. The production unit under study is interested to make the initial investment by installing an additional spray dryer plant. The expressive values acquied from the Monte Carlo technique established a range of certain results. The expected net present value of the cash flow is $14,605, hence the frequency chart outcomes confirmed that there is the highest level of certainty that the company will achieve its target. To forecast the net present value for the next period, the results confirmed that there are 50.73% chances of achieving the outcomes. Considering the minimum and maximum values at 80% certainty level, it was observed that 80% chances exist that expected outcomes will be between $5,830 and $22,587. The model’s sensitivity results validated that cash inflows had a greater sensitivity level of 21.1% and the cash inflows for the next year as 19.7%. Cumulative frequency distribution confirmed that the probability to achieve a maximum value of $23,520 is 90 % and for the value of $6,244 it is about 10 %. These validations suggested that controlling the expenditures, the company’s outflows can also be controlled definitely.
Źródło:
Management and Production Engineering Review; 2019, 10, 4; 81-89
2080-8208
2082-1344
Pojawia się w:
Management and Production Engineering Review
Dostawca treści:
Biblioteka Nauki
Artykuł

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