Wszystkie pola: availability - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Modeling of Complex Non-Full-Availability Systems
Autorzy:: Hanczewski, Sławomir
Stasiak, Maciej
Weissenberg, Michał
Powiązania:: https://bibliotekanauki.pl/articles/309499.pdf
Data publikacji:: 2020
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: analytical model
availability
non-full availability systems
Opis:: This article presents an analytical model of complex non-full-availability telecommunications systems. The high degree of accuracy of the model is demonstrated by a comparison with the results of simulation experiments. Due to the introduction of an availability parameter, this model may be used in the future for analyzing real systems, such as, for example, cloud computing infrastructure. This will be possible provided that the function combining the physical structure of the system and the availability parameter is speciﬁed. This problem will be addressed in our future work and will constitute the next stage of research undertaken by the authors.
Źródło:: Journal of Telecommunications and Information Technology; 2020, 2; 70-77
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Effect of nitrogen fertilization on Cu, Mn, Zn, Fe, B and Mo availability in commercially grown white head cabbage
Wplyw nawozenia azotem na dostepnosc Cu, Mn, Zn, Fe, B i Mo w kapuscie glowiastej bialej odm. Galaxy F1 uprawianej w warunkach produkcyjnych
Autorzy:: Domagala-Swiatkiewicz, I
Sady, W.
Powiązania:: https://bibliotekanauki.pl/articles/15142.pdf
Data publikacji:: 2010
Wydawca:: Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Tematy:: nitrogen fertilization
copper availability
manganese availability
zinc availability
iron availability
molybdenum availability
availability
white head cabbage
plant cultivation
vegetable
micronutrient content
nitrogen application
Opis:: The results of three-year investigations with cv. Galaxy F1 cabbage grown commercially in an important agricultural region of South Poland are presented. The effect of the rate of ammonium sulphate and UAN (solution of ammonium nitrate + urea), the method of application (placement and broadcast technique) and foliar fertilization (urea and Supervit K) on Cu, Mn, Zn, Fe, B and Mo concentrations in edible parts of cabbage were surveyed. Nitrogen fertilizer was applied at the rate of 120 kg N ha–1. With the placement fertilization method, fertilizer was applied in rows 10 cm deep and 10 cm away from each plant when seedlings were transplanted. Foliar sprayings started at the beginning of intensive leaf growth and continued during the growing season at two-week interval. The foliar nutrition with 2% urea was carried out 3 times and 1% Supervit K was applied once. The field experiment was carried out in 2005-2007 with cv. Galaxy F1 white cabbage on silty clay soil containing 0.91-1.02% organic carbon and soil acidity pHH2O 7.18-8.21 Micronutrient concentrations were below the lower range of the content reported for cabbage grown in non-contaminated areas. Ammonium sulphate significantly increased Mn and Fe concentrations in cabbage heads and decreased B and Mo content. However, the environmental factors considerably modified this tendency. The method of N application affected Mn content in cabbage in 2007 and Mo in 2006 and 2007. Slightly higher manganese and molybdenum concentrations for placement fertilization were noted. In 2005 and 2006, the placement fertilization at the rate of 75% N and supplemented foliar sprays increased Mo content in cabbage.
Doświadczenie z kapustą głowiastą białą odm. Galaxy F1 prowadzono w latach 2005- -2007, w prywatnym gospodarstwie warzywniczym, w Zagorzycach k. Miechowa. Badano wpływ rodzaju nawozu azotowego (siarczan amonu, RSM – roztwór saletrzano-mocznikowy), sposobu nawożenia (rzutowy, zlokalizowany) oraz dokarmiania pozakorzeniowego (mocznik i Supervit K) na stopień odżywienia roślin mikroelementami (Cu, Mn, Zn, Fe, B i Mo). Azot stosowano w dawce 120 kg N ha–1. Nawożenie zlokalizowane polegało na umieszczaniu depozytów azotowych w rzędach roślin – w odległości 10 cm od rośliny i na głębokości 10 cm – w chwili sadzenia rozsady. W obiektach z dokarmianiem dolistnym opryski wykonywano 4-krotnie, rozpoczynając na początku fazy intensywnego wzrostu wegetatywnego. W pierwszym, drugim i czwartym terminie dokarmianie wykonano z użyciem 2% roztworu mocznika, natomiast w trzecim terminie stosowano 1% roztworu Supervitu K. Kapustę uprawiano na glebie ciężkiej o składzie pyłu ilastego, zawartości węgla organicznego (%C) 0,91-1,02% i odczynie pHH2O 7,18-8,21. Rodzaj zastosowanego nawozu azotowego wpływał istotnie na zawartość Mn, Fe, B i Mo w kapuście. Istotnie więcej Mn i Fe zawierały rośliny nawożone siarczanem amonu w porównaniu z roztworem saletrzano-mocznikowym (RSM), natomiast RSM wpływał na wzrost w liściach kapusty zawartości B i Mo. Obserwowany wpływ nawozów na oznaczane w materiale roślinnym składniki zależał od warunków środowiskowych w kolejnych latach badań. Sposób stosowania nawozów azotowych wpływał na zawartość Mn i Mo w kapuście. Lokalizowanie depozytów azotowych w pobliżu roślin miało wpływ na wzrost zawartości Mn i Mo w roślinach w porównaniu z rzutowym stosowaniem siarczanu amonu i RSM. Pozakorzeniowe dokarmianie roślin z wykorzystaniem mocznika i Supervitu K zawierającego molibden wpływało na wzrost stężenia Mo w kapuście w przypadku zlokalizowanego doglebowego nawożenia azotem.
Źródło:: Journal of Elementology; 2010, 15, 3; 455-465
1644-2296
Pojawia się w:: Journal of Elementology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Ocena dostępności informacji
Information availability assessment
Autorzy:: Michalski, A.
Powiązania:: https://bibliotekanauki.pl/articles/186708.pdf
Data publikacji:: 2009
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Technik Innowacyjnych EMAG
Tematy:: dostępność informacji
informacja
information
information availability
Opis:: W artykule przeanalizowano pojęcie i znaczenie dostępności informacji w organizacji gospodarczej oraz zaproponowano zintegrowane kryterium do oceny aktualnej dostępności informacji. Przedstawiono także sposób wykorzystania zaproponowanej oceny w oparciu o realne scenariusze, które dotyczą organizacji, podchodzących w różny sposób do zagadnień zapewnienia dostępności informacji. Podane zostały uzyskane wartości zintegrowanej oceny dla poszczególnych scenariuszy.
In the article the author analyzed the concept and significance of information availability in an organization and proposed an integrated criterion for assessing the current availability of information. Additionally, the article presents the method to use the proposed assessment on the basis of real scenarios with respect to organizations where the issues of information availability are approached in different ways. Finally, the integrated assessment values for particular scenarios are given.
Źródło:: Mechanizacja i Automatyzacja Górnictwa; 2009, R. 47, nr 8, 8; 38-50
0208-7448
Pojawia się w:: Mechanizacja i Automatyzacja Górnictwa
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Availability of WDM Multi Ring Networks
Autorzy:: Rados, I.
Rados, K.
Powiązania:: https://bibliotekanauki.pl/articles/309294.pdf
Data publikacji:: 2015
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: algebraic
availability
multiple
WDM
Opis:: This paper presents a new approach to modeling the availability of the networks composed of multiple interconnected rings in two nodes. For availability modeling method algebraic formulation is used. Using this method, through the availability of multiple ring networks consisting of two and three-rings connected to two nodes, a general expression for the availability between two terminals of multiple ring networks is derived. To perform the expression some real assumptions were taken and the analytical calculation showed that the use of these expressions under these assumptions provides real values for availability between the two terminals of multiple ring networks. Information on the availability of links and nodes is taken from previously published works.
Źródło:: Journal of Telecommunications and Information Technology; 2015, 1; 53-58
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: Availability analysis and comparison of different WDM systems
Autorzy:: Rados, I.
Powiązania:: https://bibliotekanauki.pl/articles/308769.pdf
Data publikacji:: 2007
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: WDM
wavelength channel
availability
protection
Opis:: We begin reasons why high system availability is important. Furthermore, the basic terms are introduced pertaining to the availability with particular review of the parallel structure. Then the availability of different wavelength division multiplexing (WDM) systems is analysed: point to point, chain and ring with 1+1 protection of the wavelength channel, plus the influence of availability of nodes and links on the total system availability. The data on failure intensity and mean time to repair of certain components were taken from various literature sources. We assumed in the analysis a WDM system with 16 wavelengths and 2.5 Gbit/s capacity per wavelength channel. Finally, results of calculation and comparisons of availability of different WDM systems and proposals for improvement of their availability are presented.
Źródło:: Journal of Telecommunications and Information Technology; 2007, 2; 114-119
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Web server performance and availability model for simulation
Autorzy:: Walkowiak, T.
Powiązania:: https://bibliotekanauki.pl/articles/2069132.pdf
Data publikacji:: 2012
Wydawca:: Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:: performance
availability
simulation
web system
Opis:: The paper presents an approach to modelling and simulation of web systems. The systems are being modelled from the point of view of services realized by them. The formal model of a system, accompanied with a model of a request realization is presented. The main aspect of the paper is a simulation model of client-server interactions that adequately describes the relationship between the server response time, its availability and resource utilization. The model was constructed based on the the results of multiple experiments presented in a paper. Moreover, it was implemented in the simulation tool and its accuracy verified against testbed web servers. Apache and IIS servers were analysed.
Źródło:: Journal of Polish Safety and Reliability Association; 2012, 3, 2; 189--196
2084-5316
Pojawia się w:: Journal of Polish Safety and Reliability Association
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Application of Markov Chains to analyse the AIS availability
Autorzy:: Jaskólski, K.
Powiązania:: https://bibliotekanauki.pl/articles/320723.pdf
Data publikacji:: 2011
Wydawca:: Polskie Forum Nawigacyjne
Tematy:: AIS
availability
Markov chain
Opis:: Despite the initial objections, crew members and vessel traffic service staff use automatic identification system in their activities. In the phase of system implementation, inability to receive signals at scheduled time was raised, and evidenced. The research on AIS availability was conducted by the authors in 2006 and the results were presented in [Felski A., Jaskólski K, 2011]. This paper analyses the problem of AIS availability. Availability has been studied from the standpoint of the quality of data transmission channel. An attempt was made to assess the availability of the AIS service transmission channel. For this purpose, the theory of Markov processes defined on a discrete state space was applied. The Criterion of state system availability was adopted, stochastic matrix of probabilities of transitions between the states of the availability and accessibility of states limit the probability of AIS. In this paper, author proposed a model for the assessment of AIS Service availability. To meet the objective of the research, recorded data derived from the AIS Base Station HEL were used.
Źródło:: Annual of Navigation; 2011, 18; 5-16
1640-8632
Pojawia się w:: Annual of Navigation
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 8.

Tytuł:: Overview and implementing sql server high availability solutions
Autorzy:: Bleja, M.
Powiązania:: https://bibliotekanauki.pl/articles/94781.pdf
Data publikacji:: 2016
Wydawca:: Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:: high availability
windows clusters
availability group
failover cluster instance
database mirroring
log shipping
SQL Server
baza danych
serwer bazodanowy
Opis:: The paper presents the concepts related to the design of high availability solutions for Microsoft SQL (MS SQL) Server database servers. MS SQL Server from version 2012 offers a new capability called AlwaysOn which is aimed at reducing downtime of servers or databases during a failure. It includes several mechanisms such as Failover Cluster Instances, Availability Groups, Database mirroring, Log shipping. The paper presents the implementation of some of these concepts in our prototype. We also compare these mechanisms focusing on their aptitude in contemporary information systems.
Źródło:: Information Systems in Management; 2016, 5, 4; 463-472
2084-5537
2544-1728
Pojawia się w:: Information Systems in Management
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 9.

Tytuł:: Przywracanie dostępności informacji
Recovery of information availability
Autorzy:: Michalski, A.
Powiązania:: https://bibliotekanauki.pl/articles/186526.pdf
Data publikacji:: 2013
Wydawca:: Sieć Badawcza Łukasiewicz - Instytut Technik Innowacyjnych EMAG
Tematy:: dostępność informacji
działalność przedsiębiorstw
information availability
business activity
Opis:: W początkowych rozdziałach artykułu zwrócono uwagę na znaczenie dostępności informacji w działalności biznesowej przedsiębiorstwa. Następnie omówiono przyczyny utraty dostępności informacji. Zasadniczą część referatu stanowi opis autorskiej adaptacji metodyki firmy Kepner-Tregoe (pierwotnie wykorzystywanej w działalności serwisowej) do przywracania dostępności informacji. Przedstawiono także rzeczywisty przykład, ilustrujący zastosowanie omówionej metodyki w praktyce. Wykorzystywana bibliografia obejmuje jedenaście pozycji.
In the initial chapters of the article the author points out at the significance of information availability in the business operation of an organization. Then the reasons of information availability loss are discussed. The basic part of the article is the description of the Kepner-Tregoe methodology (originally used for services provision) in the recovery of information availability. Additionally, an example is given to illustrate the application of the discussed methodology in practice. The list of references includes 11 items.
Źródło:: Mechanizacja i Automatyzacja Górnictwa; 2013, R. 51, nr 6, 6; 13-17
0208-7448
Pojawia się w:: Mechanizacja i Automatyzacja Górnictwa
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 10.

Tytuł:: Availability Analysis of Different PON Models
Autorzy:: Radoš, K.
Radoš, I.
Powiązania:: https://bibliotekanauki.pl/articles/308610.pdf
Data publikacji:: 2017
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: availability
failure
Passive Optical Network
protection ﬁber
Opis:: Due to the increasing demands of individual users, Passive Optical Networks (PON) are a promising technology for future broadband access networks. Reliable access to network services is a very important feature, so the availability of the connection is becoming one of the most important requirements. Failure of the optical ﬁber occurring between the Optical Line Terminal (OLT) and the passive optical splitter can cause the services becoming unavailable for a large number of users, so it is necessary to prevent such an occurrence by providing backup resources – in this case a spare optical ﬁber. When constructing the spare path (protection ﬁber), it is important to keep in mind that, if possible, the working and the spare ﬁber should not be positioned within the same cable. Failure of the optical ﬁber between the passive splitter and the individual user also means a loss of service for that user. In that case, protection may be offered by adding spare ﬁbers. The question is, however, whether such a solution is cost-effective, as it would lead to a signiﬁcant cost increase in the construction of the access network. This paper presents the availability analysis conducted for different PON models.
Źródło:: Journal of Telecommunications and Information Technology; 2017, 4; 47-53
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 11.

Tytuł:: Availability of AIS binary data transmission based on dynamic measurements performed
Autorzy:: Jaskólski, K.
Powiązania:: https://bibliotekanauki.pl/articles/320538.pdf
Data publikacji:: 2013
Wydawca:: Polskie Forum Nawigacyjne
Tematy:: AIS
Markov process
availability
Opis:: The problem of determining coordinates for the requirements of maritime navigation, considered only in terms of measurement error, seems to be solved on a global scale. In view of the above, the operational characteristics of radio navigation systems such as availability are equally important. This paper analyses the problem of AIS binary transmission availability. An attempt was made to assess the availability of the AIS service transmission channel based on dynamic measurements. For this purpose, the theory of Markov processes defined on a discrete state space was applied. The Criterion of state system availability was adopted, stochastic matrix of probabilities of transitions between the states of the availability and accessibility of states limit the probability of AIS. In this paper, the author proposed a model for the assessment of AIS Service availability. To meet the objective of the research, recorded data derived from the Southern Baltic and Danish Straits Base Stations were used.
Dokładności, jakie zapewniają współczesne systemy satelitarne, sprawiają, że problem wyznaczania współrzędnych pozycji dla celów żeglugi morskiej w kategoriach minimalizacji błędów pomiaru wydaje się być rozwiązany w skali globalnej. Wobec powyższego równie ważna staje się operacyjna charakterystyka systemów radionawigacyjnych w oparciu o takie wielkości, jak na przykład dostępność. W artykule przedstawiono analizę zagadnienia dostępności transmisji binarnej w systemie AIS. Badania przeprowadzono dla oszacowania dostępności kanału transmisji AIS w oparciu o pomiary z obiektu ruchomego. W tym celu zastosowano teorię procesów Markova zdefiniowanych na dyskretnej przestrzeni stanów. Adaptowano kryterium stanu dostępności systemu opisane stochastyczną matrycą prawdopodobieństw przejść między stanami. Autor zaproponował model dla oszacowania dostępności AIS. Badania wykonano na danych zarejestrowanych na południowym Bałtyku oraz w cieśninach bałtyckich.
Źródło:: Annual of Navigation; 2013, 20; 25-36
1640-8632
Pojawia się w:: Annual of Navigation
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 12.

Tytuł:: Approach to increase both operators' safety and devices' availability under operation
Autorzy:: Gliwiński, M.
Szpytko, J.
Powiązania:: https://bibliotekanauki.pl/articles/246134.pdf
Data publikacji:: 2010
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: availability
operator
devices
Opis:: The paper is focusing on increasing both operators' safety and devices' availability under operation. Each process supported by any composition of the man-devices set it is possible to present and described by selected operation (exploitation) parameters, which can be a subject of monitoring. With use process operation parameters set the target-oriented production Key Performance Indicator has been proposed. Base on Key Performance Indicator both operators' safety and devices' availability analysis is possible in practice. Paper composition contains: solution description, good practice examples discussion and conclusions. Safety of man/ operators and availability of devices are very important for everybody and using preventive one solution we can increase and protect both. Additional process operation parameters monitoring, as well as measuring, are an important factors increases people 's awareness. Two different approaches of the same process have been described on examples coming from manufacture. The following approaches have been taken under consideration: traditional one based on reactive maintenance and new approach based on preventive maintenance. The comparison of both scenarios was discussed. For human's safety and dependability of devices, responsibility of all involved employees in practice is equal.
Źródło:: Journal of KONES; 2010, 17, 1; 143-147
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 13.

Tytuł:: Influence of common path on availability of ring network
Autorzy:: Rados, I.
Powiązania:: https://bibliotekanauki.pl/articles/308932.pdf
Data publikacji:: 2004
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: availability
failure rate
protection
ring networks
SDH networks
Opis:: This paper analyses availability of the ring network which uses the path protection switching (sub-network connection protection - SNCP). Influence of the common path on the ring network availability is analyzed. Data regarding failures of optical fibre cables and equipment used for calculations have been obtained during years-long observation of SDH network in HT Mostar as well as from manufacturers.
Źródło:: Journal of Telecommunications and Information Technology; 2004, 3; 71-75
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 14.

Tytuł:: Expedient methods of sustaining weapon system availability
Autorzy:: Smal, T.
Powiązania:: https://bibliotekanauki.pl/articles/348053.pdf
Data publikacji:: 2017
Wydawca:: Akademia Wojsk Lądowych imienia generała Tadeusza Kościuszki
Tematy:: combat service support
availability
weapon systems
expedient repair
battle damage repair
Opis:: The paper presents an expedient repair system in the context of sustaining weapon system availability under combat operations. Firstly, the crucial processes of battlefield maintenance were defined and principles and nature of expedient (temporary, improvised) repairs were described. Additionally, basic allied documents related to battlefield maintenance and expedient repair were mentioned. Furthermore, expedient repair systems in selected allied armies were briefly described in order to identify the basic elements of the expedient repair system, which are common for all allies. The identified elements were shortly characterized.
Źródło:: Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki; 2017, 1; 201-211
1731-8157
Pojawia się w:: Zeszyty Naukowe / Wyższa Szkoła Oficerska Wojsk Lądowych im. gen. T. Kościuszki
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 15.

Tytuł:: Selected issues of reliability and availability in marine vessel fire alarm systems
Autorzy:: Bistrović, Miroslav
Powiązania:: https://bibliotekanauki.pl/articles/135156.pdf
Data publikacji:: 2019
Wydawca:: Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:: reliability
safety
protection
availability
fire alarm system
human factor
Opis:: Today, every industry is striving for the highest efficiency and best economic results possible, with the greatest possible competitiveness. But in maritime affairs, human safety and environmental protection are the foundations of sustainability. To achieve this, marine systems must be reliable, high quality and easy to maintain. Because of this, reliability has become an important factor in safety, which remains relevant throughout the lifetimes of ship systems, including fire alarm systems. In this paper we address a number of issues connected with the reliability – and ‘availability’ of these systems. Firstly, ship fire alarm systems consist of various components whose individual reliability affect the system’s overall reliability. Discussions of reliability in ship fire alarm systems normally focus on the length of a system’s useful life or performance during design-based fire events. In addition to the reliability of systems, their availability for use is also crucial given the possibility that the system may need to operate at any point in time.
Źródło:: Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2019, 60 (132); 177-183
1733-8670
2392-0378
Pojawia się w:: Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 16.

Tytuł:: Analysis of the Impact of Unscheduled Downtimes on their Availability in Machine Operations
Autorzy:: Brodny, J.
Powiązania:: https://bibliotekanauki.pl/articles/2064991.pdf
Data publikacji:: 2018
Wydawca:: STE GROUP
Tematy:: mining production
unscheduled downtimes
mining machines
efficiency
availability
Opis:: Unscheduled downtimes in machine operation are one of the main reasons behind their low availability. Such downtimes are caused by miscellaneous factors and remain difficult to identify in a number of cases. This particularly refers to enterprises that conduct their activities in changing external conditions, such as hard coal mines, where exploitation is carried out in extremely complicated, changeable and dangerous conditions. The process of coal production makes use of various machines that must be adapted to these conditions. The specificity of the working environment makes it necessary for these machines to exhibit high reliability, readiness and efficiency. These features, in turn, make the cost of the machines very high. It is therefore reasonable to make the best use of their capabilities, which translates into the effectiveness of the entire production process. The article concentrates on determining the availability of these machines. It has been assumed that availability is one of the fundamental parameters that define the effective utilisation of machines. The tests were conducted for a longwall shearer as well as an armoured face conveyor and a main haulage conveyor in one of the hard coal mines in Poland. Industrial automation systems were used to determine unscheduled downtimes in the operation of these machines, as well as their time structure and causes. The results obtained indicate that the number of unscheduled downtimes represents a serious problem in mining exploitation.
Źródło:: Multidisciplinary Aspects of Production Engineering; 2018, 1, 1; 145--151
2545-2827
Pojawia się w:: Multidisciplinary Aspects of Production Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 17.

Tytuł:: Availability Study of a Longwall Shearer Including Phases of its Operation
Autorzy:: Brodny, Jarosław
Brzana, Estera
Powiązania:: https://bibliotekanauki.pl/articles/2064591.pdf
Data publikacji:: 2021
Wydawca:: STE GROUP
Tematy:: mining machines
efficiency
machine availability
OEE
industrial automation
Opis:: The mining production process includes a number of sub-processes, the most important of which is mining the rock mass. In this process, increasingly modern mining machines are being used to replace human labor and to achieve high productivity. Full utilization of the potential of these machines is of great importance for the efficiency of individual stages and the whole process of mining production. In the process of mining the rock mass, the use of machinery of a mechanized longwall system is of fundamental significance. Their availability, efficiency and reliability significantly affect the efficiency of the whole mining production process. The paper refers to the availability of a longwall shearer as the basic machine of a mechanized mining system. Based on the analysis of diagnostic signals, recorded by the industrial automation system, the availability of the longwall shearer was determined for 10 selected cycles of its operation. The analysis also included the phases of these cycles, treated as separate periods of the shearer’s work. This division is a consequence of a great difference in the character of the shearer’s work in particular phases of the operating cycle. The analysis covered the phases of cutting, mining and shunting. The determined temporal waveforms and the shearer’s availability in these phases show their great diversity. Therefore, the results indicated the necessity to analyze the operation of mining machines in their characteristic periods, which can be the basis for minimizing unplanned interruptions in their operation and improving the efficiency of their use.
Źródło:: Multidisciplinary Aspects of Production Engineering; 2021, 4, 1; 200--211
2545-2827
Pojawia się w:: Multidisciplinary Aspects of Production Engineering
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 18.

Tytuł:: Probabilistic models for analyzing the availability and profit of a deteriorating 2-out-of-4 system
Autorzy:: Yusuf, I.
Powiązania:: https://bibliotekanauki.pl/articles/406425.pdf
Data publikacji:: 2016
Wydawca:: Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:: deterioration
linear consecutive
profit
availability
Opis:: This paper deals with modelling and evaluating the availability and profit of a linear consecutive 2-out-of-4 system exposed to three consecutive stages of deterioration before failure. The system will pass through three consecutive stages of deterioration: slow, medium and fast before failure. The failure and repair times are assumed to be exponentially distributed. Explicit expressions for the system avail-ability, the probability of a repairman being busy due to the failure of a unit, or due to the replacement of failed units, and the profit function have been derived using a probabilistic approach. The impacts of the failure and repair rate on system availability and profit have been investigated. The results of this paper will enhance system performance and ensure the timely execution of appropriate maintenance and improvement, and thus is a major tool for decision making, planning and optimisation.
Źródło:: Operations Research and Decisions; 2016, 26, 4; 91-100
2081-8858
2391-6060
Pojawia się w:: Operations Research and Decisions
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 19.

Tytuł:: Measurements and Statistical Analysis for Assessment of Availability of Mobile Network Services
Autorzy:: Kadamus, G.
Langer, M.
Powiązania:: https://bibliotekanauki.pl/articles/308214.pdf
Data publikacji:: 2018
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: availability
Diversity Benchmarker
Monte Carlo
quality of experience
Opis:: Availability is an essential feature of telecommunication services. It inﬂuences the quality of experience (QoE) associated with individual networks and with the services offered. Therefore, it needs to be allowed for at each level of network design, and has to be controlled at the operation stage. This is achieved by means of various mathematical and numerical tools. In this project listening quality and speech level, which are quality-related features of mobile network services, are measured and analyzed with the Monte Carlo simulation method. Measurements are taken with assistance of the Diversity Benchmarker, a reliable device designed for mobile network testing. Finally, results obtained are compared to assess the applicability of the Monte Carlo method.
Źródło:: Journal of Telecommunications and Information Technology; 2018, 2; 48-52
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 20.

Tytuł:: Model-Based Availability Evaluation of Composed Web Services
Autorzy:: Iacono, M.
Marrone, S.
Powiązania:: https://bibliotekanauki.pl/articles/309381.pdf
Data publikacji:: 2014
Wydawca:: Instytut Łączności - Państwowy Instytut Badawczy
Tematy:: automatic model generation
Composed Web Services
fault tree
model composition
service availability
Opis:: Web services composition is an emerging software development paradigm for the implementation of distributed computing systems, the impact of which is very relevant both in research and industry. When a complex functionality has to be delivered on the Internet, a service integrator can produce added value by delivering more abstract and complex services obtained by composition of existing ones. But while isolated services availability can be improved by tuning and reconguring their hosting servers, with Composed Web Services (CWS) basic services must be taken as they are. In this case, it is necessary to evaluate the composition eects. The authors propose a high-level analysis methodology, supported by a tool, based on the transformation of BPEL descriptions of CWS into models based on the fault tree availability evaluation formalism that enables a modeler, unfamiliar with the underlying combinatorial probabilistic mathematics, to evaluate the availability of CWS, given components availability and expected execution behavior.
Źródło:: Journal of Telecommunications and Information Technology; 2014, 4; 5-13
1509-4553
1899-8852
Pojawia się w:: Journal of Telecommunications and Information Technology
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 21.

Tytuł:: The quantification method of functional availability military vehicles
Autorzy:: Przybysz, Kamil
Powiązania:: https://bibliotekanauki.pl/articles/1537426.pdf
Data publikacji:: 2020
Wydawca:: Centrum Rzeczoznawstwa Budowlanego Sp. z o.o.
Tematy:: functional availability
safety
reliability
semi-Markov models
dostępność funkcjonalna
bezpieczeństwo
niezawodność
model semi-Markowa
Opis:: The availability is one of the most important feature of a technical object which shapes its operational quality. The paper undertakes the issue related to the quantification of functional availability of vehicles, with reference to reliability aspects. The conducted exploitation research paved the way for elaborating methods of determining functional availability for vehicles, in particular focusing on reliability. The essential research was conducted using the developed mathematical model based on the probabilistic, stochastic Markov process, which allowed modelling the process of changes in the exploitation states of vehicles. In view of the above, it is essential to develop methods that enable the most accurate estimation of the functional availability of vehicles. Knowing the values of functional availability, we can estimate the probability of performing assigned tasks and precisely control the vehicle exploitation system, especially in terms of availability, which is important for vehicles. This work presents a method for determining the functional availability of vehicles, taking into account the limitations introduced by the vehicle exploitation system. Particular attention was paid to the possibility of using probabilistic, stochastic semiMarkov models, whose rules and method of creation were generally described, with regard to the ability to acquire operational data in the vehicle exploitation system.
Źródło:: Inżynieria Bezpieczeństwa Obiektów Antropogenicznych; 2020, 4; 1-11
2450-1859
2450-8721
Pojawia się w:: Inżynieria Bezpieczeństwa Obiektów Antropogenicznych
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 22.

Tytuł:: Analiza dostępności konstelacji satelitów
Availability analysis of satellite constellation
Autorzy:: Zheng, H.
Ren, L.
Powiązania:: https://bibliotekanauki.pl/articles/301053.pdf
Data publikacji:: 2010
Wydawca:: Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:: konstelacje satelitów
analiza dostępności
analiza przestojów
satellite constellations
availability analysis
outage analysis
Opis:: This paper firstly analyzes the concept of availability of satellite constellation. Then the method of constellation availability analysis is proposed based on Markov chain model, outage analysis, as well as MTBF and MTTR of satellite constellations. Finally, an illustrative example is presented to demonstrate the method.
Artykuł w pierwszej kolejności analizuje pojęcie dostępności konstelacji satelitów. Następnie proponuje metodę analizy dostępności konstelacji opartą na modelu łańcuchów Markowa, analizie przestojów, oraz MTBF i MTTR konstelacji satelitów. Metodę zilustrowano przykładem.
Źródło:: Eksploatacja i Niezawodność; 2010, 2; 48-50
1507-2711
Pojawia się w:: Eksploatacja i Niezawodność
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 23.

Tytuł:: Method for assessment and control of availability of executive subsystem of a transportation system
Autorzy:: Woropay, M.
Migawa, K.
Powiązania:: https://bibliotekanauki.pl/articles/246869.pdf
Data publikacji:: 2012
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport system
availability
operation and maintenance process
Opis:: In this work, a method for assessment and control of availability of executive subsystem consisting of elementary subsystems of the type has been presented. The goal of the executive subsystem is to perform the assigned transport tasks over set routes, with a given frequency, according to a set schedule. A proper accomplishment of the transport task is possible only if the required number of technical objects (transport means) is prepared to perform the assigned task in a given time. Among many significant criteria used for assessment of a transport system operation there is one of special importance that is availability of the executive subsystem to perform the assigned tasks. Availability of the executive system to perform the assigned tasks depends on availability of particular technical objects (transport means) used in the system of transportation and their number. On the basis of the above statement, it can be said that control of the executive subsystem availability can be carried out both by selecting technical objects with the required availability and matching the required number of the objects which are to be used in the system in order to ensure proper accomplishment of the transport tasks. In this work there has been discussed a method for determination of the required availability of a single object as well as the required number of technical objects indispensable to perform appropriately the assigned transport task, on the basis of the transportation system availability assessment. Availability of the transportation system is determined on the basis of a mathematical model of the operation and maintenance process of technical objects, in the studied transportation system. Exemplary results have been presented on the basis of experimental data, obtained from the tests carried out in a real operation and maintenance system of transport means.
Źródło:: Journal of KONES; 2012, 19, 3; 491-498
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 24.

Tytuł:: Analiza porównawcza rozwiązań wysokiej dostępności
Comparative Analysis of High Availability Solutions
Autorzy:: Borsewicz, Michał Sylwester
Bieniek, Daniel
Powiązania:: https://bibliotekanauki.pl/articles/98470.pdf
Data publikacji:: 2019
Wydawca:: Politechnika Lubelska. Instytut Informatyki
Tematy:: klaster
wysoka dostępność
Hyper-V
vSphere
cluster
high availability
Opis:: Celem niniejszej pracy jest przedstawienie analizy porównawczej wybranych rozwiązań wysokiej dostępności. Problematyka wyboru odpowiednich rozwiązań HA jest nieodzowną częścią każdej firmy korzystającej z infrastruktury IT. Jako, że komercyjnie najczęściej stosowane są rozwiązania wirtualizacyjne firm Microsoft: Hyper-V oraz VMWare: vSphere, to zostały one poddane dogłębniejszej analizie. W tym celu wykonano testy wydajnościowe systemów gości na powyższych hypervisorach oraz przetestowano działanie klastra w sytuacji awarii jednego z hostów.
The aim of the thesis was to perform a comparative analysis of selected high availability solutions. The issue of choosing the right HA solutions is an indispensable part of any company that uses IT infrastructure. As the most commonly used solutions are the virtualization solutions of Microsoft: Hyper-V and VMWare: vSphere, they have been subjected to in-depth analysis. For this purpose, we have performed performance tests of guest systems on the above hypervisors and we tested the behavior of the cluster in the event of failure of one of the hosts.
Źródło:: Journal of Computer Sciences Institute; 2019, 12; 240-245
2544-0764
Pojawia się w:: Journal of Computer Sciences Institute
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 25.

Tytuł:: Route Availability Model for Inter-working Multi-hop Wireless Networks
Autorzy:: Salami, O.
Bagula, A.
Chan, H. A.
Powiązania:: https://bibliotekanauki.pl/articles/226944.pdf
Data publikacji:: 2010
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: inter-working
multi-hop
route availability
wireless network
Opis:: In order to link a source-destination node pair in inter-working multi-hop wireless networks, links or routes must first be available. It is only after establishing the availability of links and routes between nodes that factors which affect connectivity e.g. interference can be considered. Connectivity in multi-hop wireless networks has been studied. However, the studies focused on network connectivity in ad-hoc networks. Since the next generation of wireless networks will be inter-working, an understanding of connectivity as it applies to such networks is needed. Specifically, this paper emphasizes that an analysis of route connectivity rather than network connectivity is needed for inter-working multi-hop wireless networks. With a focus on route connectivity, a route availability model for inter-working multi-hop wireless networks is presented.
Źródło:: International Journal of Electronics and Telecommunications; 2010, 56, 2; 185-190
2300-1933
Pojawia się w:: International Journal of Electronics and Telecommunications
Dostawca treści:: Biblioteka Nauki

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