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Tytuł:
Mathematical models in hydrology
Autorzy:
Kundzewicz, Zbigniew
Powiązania:
https://bibliotekanauki.pl/articles/748418.pdf
Data publikacji:
1979
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Hydrology, hydrography, oceanography
Flows in porous media, filtration, seepage
Opis:
.
The author outlines the main modeling techniques in hydrology (the science of water circulation in nature). Specifically, he discusses the Saint-Venant model, the "black box'' approach, the Kalinin-Niljukov model, and some more heuristically formulated approaches.
Źródło:
Mathematica Applicanda; 1979, 7, 14
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models in epidemiology and immunology
Autorzy:
Foryś, Urszula
Powiązania:
https://bibliotekanauki.pl/articles/748317.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Epidemiology
Opis:
Artykuł nie zawiera streszczenia
The article contains no abstract
Źródło:
Mathematica Applicanda; 2000, 28, 42/01
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models in biology - an introduction
Autorzy:
Lachowicz, Mirosław
Powiązania:
https://bibliotekanauki.pl/articles/748281.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Research exposition
Opis:
Artykuł nie zawiera streszczenia
The article contains no abstract
Źródło:
Mathematica Applicanda; 2000, 28, 42/01
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The agricultural production in mathematical models
Autorzy:
Parlinska, M.
Dareev, G.
Powiązania:
https://bibliotekanauki.pl/articles/572910.pdf
Data publikacji:
2011
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
agricultural production
mathematical model
agriculture
production function
analysis method
economic process
technological process
Opis:
The theoretical questions of mathematical modeling of agricultural production processes are described. Production of agricultural goods and foodstuffs is modeled except for the production of forage and involvement of equipment and techniques, buildings, infrastructure etc. The model is based on a division of economic and technological processes in agriculture into four stages specific for agribusiness. A mathematical description of four stages in used production functions is provided.
Źródło:
Zeszyty Naukowe Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie. Problemy Rolnictwa Światowego; 2011, 11(26), 3
2081-6960
Pojawia się w:
Zeszyty Naukowe Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie. Problemy Rolnictwa Światowego
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlinear mathematical models of weakly loaded contact joints
Autorzy:
Skrodzewicz, J.
Gutowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/279491.pdf
Data publikacji:
2000
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
contact joint
energy dissipation
nonlinear models
Opis:
The paper presents nonlinear mathematical models describing the properties of dry and lubricated contact joints loaded in normal direction. The energy dissipation coefficient... is expressed as a function of the load amplitude. The structure of the models is defined on the basis of the experimentally determined spectral-response characteristics of relative displacements of the contact surfaces, and of contact load in the normal direction. The form of the functional factors of models is estimated of the linear regression analysis.
Nieliniowe modele matematyczne połączeń stykowych słabo obciążonych. W pracy przedstawiono nieliniowe modele matematyczne opisujące właściwości połączeń stykowych suchych i smarowanych obciążonych w kierunku normalnym. Podano także zależności współczynnika rozproszenia energii... w funkcji amplitudy obciążenia. Strukturę modeli określono na podstawie eksperymentalnie wyznaczonych charakterystyk widmowych sygnałów przemieszczeń względnych nominalnych powierzchni styku i obciążenia styku w kierunku normalnym. Postaci czynników funkcyjnych modelu wyestymowano stosując metody regresji liniowej.
Źródło:
Journal of Theoretical and Applied Mechanics; 2000, 38, 4; 781-789
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sensitivity analysis of mathematical models of signalling pathways
Autorzy:
Charzynska, A.
Nalecz, A.
Rybinski, M.
Gambin, A.
Powiązania:
https://bibliotekanauki.pl/articles/80205.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
membrane receptor
differential equation
stochastic model
modelling
sensitivity analysis
mathematical model
signalling pathway
dynamic behaviour
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2012, 93, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models of ion transport through cell membrane channels
Autorzy:
Miękisz, Jacek
Gomułkiewicz, Jan
Miękisz, Stanisław
Powiązania:
https://bibliotekanauki.pl/articles/748548.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
ion channels, ion transport, Poisson-Nernst-Planck equations, non-equilibrium statistical mechanics, Kawasaki dynamics, driven lattice gases
Opis:
We discuss various models of ion transport through cell membrane channels. Recent experimental data shows that sizes of some ion channels are compared to those of ions and that only few ions may be simultaneously in any single channel. Theoretical description of ion transport in such channels should therefore take into account stochastic fluctuations and interactions between ions and between ions and channel proteins. This is not satisfied by macroscopic continuum models based on the Poisson-Nernst-Planck equations. More realistic descriptions of ion transport are offered by microscopic molecular and Brownian dynamics. We present a derivation of the Poisson-Nernst-Planck equations. We also review some recent models such as single-file diffusion and Markov chains of interacting ions (boundary driven lattice gases).Such models take into account discrete and stochastic nature of ion transport and specifically interactions between ions in ion channels.
Źródło:
Mathematica Applicanda; 2014, 42, 1
1730-2668
2299-4009
Pojawia się w:
Mathematica Applicanda
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models for specialized and sensory networks of wireless access
Autorzy:
Tymchenko, O.
Zelyanovsky, M.
Szturo, K.
Tymchenko, O. O.
Powiązania:
https://bibliotekanauki.pl/articles/298196.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
sensor networks
mathematical model
topology control
Opis:
This article reviews and compares the special features of specialized wireless and sensor networks. The components of a mathematical model of existing specialized wireless and sensor network are also available for review, particularly: wireless channel models, signal propagation models and communication graph models, etc. The need for a topology control mechanism in wireless and sensor networks is also explained.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2016, 19(2); 129-138
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Main inductances of induction motor for diagnostically specialized mathematical models
Autorzy:
Węgiel, T.
Weinreb, K.
Sułowicz, M.
Powiązania:
https://bibliotekanauki.pl/articles/141392.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
silnik indukcyjny
uszkodzenie wirnika
diagnostyka
ekscentryczność wirnika
wirnik
induction motors
rotor fault diagnosis
rotor eccentricity
Opis:
In the paper modeling of main inductances for mathematical models of induction motors is applied to study the effects caused by a rotor eccentricity and saturation effects. All three possible types of eccentricity: static, dynamic and mixed are modeled. The most important parameters describing rotor eccentricity include self and mutual inductances of the windings. The structural changes of the permeance function as a result of eccentricity appearance and the Fourier spectra of inductances in occurrence of saturation for each case are determined in the paper. The presented algorithm can be used for the diagnostically specialized models of induction motors.
Źródło:
Archives of Electrical Engineering; 2010, 59, 1-2; 51-66
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Differences in mathematical models of GPS and pseudolite observation equations
Autorzy:
Rzepecka, Z.
Wasilewski, A.
Cellmer, Sł.
Rapiński, J.
Powiązania:
https://bibliotekanauki.pl/articles/225048.pdf
Data publikacji:
2007
Wydawca:
Politechnika Warszawska. Wydział Geodezji i Kartografii
Tematy:
GPS
satelita GPS
pseudosatelita
system pozycjonowania obiektów
pomiary geodezyjne
GPS satellite
pseudo-satellite
Global Positioning System
engineering surveying
Opis:
Some error sources in GPS surveys, such as linearization error and orbital bias, are well known and do not require further investigation. The impact of these errors in GPS + pseudolite observations can be different and must be considered separately. This paper presents influence of orbital bias and linearization error on single differenced pseudolite observations.
Źródło:
Reports on Geodesy; 2007, z. 1/82; 295-301
0867-3179
Pojawia się w:
Reports on Geodesy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A series of mathematical models of mechatronic system with piezoelectric actuator
Autorzy:
Buchacz, A.
Płaczek, M.
Powiązania:
https://bibliotekanauki.pl/articles/408935.pdf
Data publikacji:
2011
Wydawca:
Politechnika Śląska
Tematy:
układ mechatroniczny
przetwornik piezoelektryczny
model matematyczny
mechatronic system
piezoelectric transducer
mathematical model
Opis:
Paper presents a process of modelling and investigation of a mechatronic system with piezoelectric transducer used as a vibration actuator - reverse piezoelectric effect is applied in considered system. A series of mathematical models of this system is presented. Characteristic that describes relation between amplitude of the system's vibration and parameters of harmonic voltage that supplied piezoelectric actuator is assigned on the basis of corrected approximate Galerkin method. Obtained results are juxtaposed and the most appropriate mathematical model of this system is chosen.
Źródło:
Wybrane Problemy Inżynierskie; 2011, 2; 47-52
2083-1021
Pojawia się w:
Wybrane Problemy Inżynierskie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models for evaluation, optimization, and control of artificial kidney therapy
Autorzy:
Waniewski, J.
Powiązania:
https://bibliotekanauki.pl/articles/332857.pdf
Data publikacji:
2002
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
dializa otrzewnowa
modelowanie kinetyczne
phemodialysis
peritoneal dialysis
kinetic modeling
Opis:
Renal replacement therapy involves the control of body pools of water and electrolytes, and removal of small metabolites (urea, creatinine). The correct estimation of "the dose of therapy" and optimisation of the procedure needs quantification of fluid and solute transport during dialysis as well as evaluation of the distribution and exchange of water and solutes within the body. Mathematical models can combine the general physiological knowledge with information about individual patients yielded by clinical measurements. Many of these models (urea model, sodium model, models of peritoneal transport) have been presented to the community of clinical nephrologists in the form of computer programs often supplemented with on-line measuring devices. However, the debate about their meaning and the search for better methods of their application are still vivid.
Źródło:
Journal of Medical Informatics & Technologies; 2002, 3; IP27-39
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Artificial Neural Network based on mathematical models used in quantum computing
Autorzy:
Ruciński, Dariusz
Powiązania:
https://bibliotekanauki.pl/articles/2201614.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Przyrodniczo-Humanistyczny w Siedlcach
Tematy:
neural modeling
Day-Ahead Market
Polish Power Exchange
Hilbert space
quantum inspired neural network
Opis:
The article is a proposition of a new approach to building a neural model based on the system of Day-Ahead Market operating at TGE S.A. The reason for the proposed method is an attempt to find a better model for the DAM system. The proposed methodology is based on using mathematical models used in quantum computing. All calculations performed on learning the Artificial Neuron Network are based on operations described in Hilbert space. The main idea of calculations is to replace the data from the decimal system into the quantum state in Hilbert space and perform learning operations for a neural model of the DAM system in a special manner which relay on the teaching model for each position of the quantum register for all data. The obtained results were compared to the “classical” neural model with the use of a comparative model.
Źródło:
Studia Informatica : systems and information technology; 2022, 2(27); 27--48
1731-2264
Pojawia się w:
Studia Informatica : systems and information technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of selected mathematical models of high-cycle S-N characteristics
Autorzy:
Strzelecki, P.
Sempruch, J.
Tomaszewski, T.
Powiązania:
https://bibliotekanauki.pl/articles/298416.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie
Tematy:
high-cycle fatigue
S-N curve
fatigue tests
number of specimen
steel strength
Opis:
The paper presents two approaches of determining S-N fatigue characteristics. The first is a commonly used and well-documented approach based on the least squares method and staircase method for limited fatigue life and fatigue limit, accordingly. The other approach employs the maximum likelihood method. The analysis of the parameters obtained through both approaches exhibited minor differences. The analysis was performed for four steel construction materials, i.e. C45+C, 45, SUS630 and AISI 1045. It should be noted that the quantity of samples required in the second approach is significantly smaller than with the first approach, which translates into lower duration and costs of tests.
Źródło:
Technical Sciences / University of Warmia and Mazury in Olsztyn; 2017, 20(3); 227-240
1505-4675
2083-4527
Pojawia się w:
Technical Sciences / University of Warmia and Mazury in Olsztyn
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uncertainty mathematical models of power converters
Niepewność modeli matematycznych układów energoelektronicznych
Autorzy:
Sieklucki, G.
Bisztyga, B.
Powiązania:
https://bibliotekanauki.pl/articles/282164.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
przekształtnik tyrystorowy
falownik napięcia
napęd elektryczny
niepewność multiplikatywna
regulator I I2
element oscylacyjny
sterowanie odporne
thyristor-controlled converter
voltage source inverter
electric drive
multiplicative uncertainty
I I2 controller
oscillatory element
robust control
Opis:
The controller synthesis problem of the motor torque with parameters changes of the power converter is presented. The parameters uncertainty of the power converters described by gain and time-delay are analysed in the article. The principles of determining the range of the parameters variations are presented. The conversion method from the parametric to the dynamic uncertainty which can be useful to a robust controller optimization, is shown. A multiplicative uncertainty weight as the oscillatory element is proposed. The tuning of the I I2 controller parameters of the electromagnetic motor torque is introduced. The results are obtained by applying the mixed sensitivity method (robust performance) which is the optimization in H∞ space.
W artykule przedstawiony został problem syntezy regulatora momentu elektromagnetycznego silnika przy zmianach parametrów układu zasilającego. W artykule analizowana jest niepewność parametrów układów zasilających silniki elektryczne, opisana przez wzmocnienie i opóźnienie czasowe. Podano zasady wyznaczania zakresu zmian tych parametrów. Przedstawiono metodę przekształcenia niepewności parametrycznej na dynamiczną, która może być wykorzystana w optymalizacji regulatora odpornego. Zaproponowano funkcję wagową niepewności multiplikatywnej w postaci elementu oscylacyjnego. Wyznaczono regulator I I2 momentu elektromagnetycznego dla silnika. Wyniki te uzyskano, stosując metodę mieszanej czułości, czyli optymalizację w przestrzeni H∞.
Źródło:
Automatyka / Automatics; 2012, 16, 1; 73-87
1429-3447
2353-0952
Pojawia się w:
Automatyka / Automatics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modele matematyczne jednofazowych linii długich
Mathematical models of single-phase long lines
Autorzy:
Figoń, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/210231.pdf
Data publikacji:
2019
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
linia długa
metoda zmiennych stanu
schemat różnicowy
power line
state variables
differential scheme
Opis:
Większość pakietów symulacyjnych udostępnia modele linii długich zawierające wyłącznie dwa zaciski wejściowe oraz dwa zaciski wyjściowe. Modele te umożliwiają badanie stanów nieustalonych inicjowanych wystąpieniem zakłócenia na krańcach linii. Z tego powodu nie ma możliwości badania zaburzeń pojawiających się w dowolnym punkcie sieci elektrycznej. W artykule szczegółowo opisano modele matematyczne linii długiej, ich implementację w środowisku Matlab oraz przedstawiono przykładowe wyniki symulacji komputerowych.
Most simulation packages provide long line models containing only two input terminals and two output terminals. These models allow testing transient states initiated by the occurrence of interference at the ends of the line. For this reason, it is not possible to study disorders occurring at any point of the electrical network. The article describes in detail the mathematical models of the long line, their implementation in the Matlab environment and exemplary results of computer simulations.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2019, 68, 4; 119-137
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models of the air separation through polymer membranes at magnetic field
Autorzy:
Strzelewicz, A.
Grzywna, Z. J.
Powiązania:
https://bibliotekanauki.pl/articles/346951.pdf
Data publikacji:
2007
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:
diffusion
membrane
time lags
gas mixtures
air separation
Opis:
This paper is addressed to the membrane air separation i.e. the gas mixture of quite similar gases in many respects, except one: oxygen is paramagnetic whereas nitrogen is diamagnetic. This fact forms the basis for their separation. The numerical studies and theoretical predictions concerning the air membrane separation in the presence of a magnetic field are discussed. Some experimental data concerning the „magnetic membranes” i.e. ethylcellulose membranes with neodymium powder, are also presented.
Źródło:
Ars Separatoria Acta; 2007, 5; 34-44
1731-6340
Pojawia się w:
Ars Separatoria Acta
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Autonomous ships concept and mathematical models application in their steering process control
Autorzy:
Melnyk, O.
Onishchenko, O.
Onyshchenko, S.
Voloshyn, A.
Kalinichenko, Y.
Rossomakha, O.
Naleva, G.
Powiązania:
https://bibliotekanauki.pl/articles/2211982.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
autonomous ship
steering process control
mathematical model
autonomous ship concept
accident-free navigation
automatic steering system
ship automatic movement
ship automatic movement control system
Opis:
Advances in computer systems and innovative technologies along with their implementation into the shipping industry not only enabled efficient data exchange between the ship and the shore, but also created a single integrated information network linking all participants of the process and all elements of the maritime sector. Development of the concept of autonomous ships and automated control facilities for their functionality became the next stage in the evolution of innovations. The process of software adaptation, additional electronic steering systems, optical and digital means of monitoring as well as satellite communication facilities for autonomous ships are among the tasks which require search and development of the solutions. Provision of reliable and safe functioning of such ships in the autonomous mode requires development of models and methods for ensuring their accident-free navigation both in relation to the process of ships divergence and improvement of automatic steering systems of movement and course steadiness. In the given work, the analysis of realization of the crewless navigation and possibility of ship automatic movement control systems advancement on the basis of application of mathematical model for the purpose of enhancement of process of the autonomous ship steadiness on the set course is proposed.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2022, 16, 3; 553--559
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel hybrid iterative method for applied mathematical models with time-efficiency
Autorzy:
Jamali, Khalid
Solangi, Muhammad Anwar
Qureshi, Sania
Powiązania:
https://bibliotekanauki.pl/articles/2202025.pdf
Data publikacji:
2022
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
nonlinear equation
computational order
efficiency index
convergence order
Newton’s method
równanie nieliniowe
Opis:
Non-linear phenomena appear in many fields of engineering and science. Research on numerical methods is continually extending with the improvement of the latest computing tools. In today’s computational field, one requires maximum achievement in a minimum amount of time. Therefore, there is a need to modify the Newton-type method to achieve higher-order convergence to solve non-linear equations. While the modified methods are expected to be higher-order convergent, the minor computational information and the maximum time efficiency are also important factors. We propose a three-step hybrid iterative method having a non-linear nature. Per iteration, the method requires three function evaluations and three first-order derivatives. The method is theoretically proven to be tenth-order convergent. The mathematical results of the proposed strategy to solve models from fluid dynamics, electric field, and real gases demonstrated better performance. In light of error analysis, computational productivity, and CPU times, the proposed method’s performance is compared to the famous Newton and a recently proposed tenth-order method.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2022, 21, 3; 19--29
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models for simulation of layer hydrodynamics of a ship fluidized bed boiler
Autorzy:
Tryczak, J. R.
Zeńczak, W.
Powiązania:
https://bibliotekanauki.pl/articles/135090.pdf
Data publikacji:
2016
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
two-phase flows
fluidized bed boilers
mathematical modeling
simulation
ship
swaying motion
Opis:
Fluidized bed boilers have been widely used for many years in energetics but their application in shipbuilding has been incidental. The hydrodynamics of a fluidized bed is a complicated issue. If the swaying of a ship on a sea wave is taken into account, this issue will be further complicated. The choice of an appropriate mathematical model is important from the viewpoint of building computer models for the simulation of a fluidized bed during disruptions that result from the ship swaying on sea waves. Fluidization is a two-phase flow process, which is described by many models such as the homogeneous-slip model or heterogeneous-slide model. The most popular models that show two-phase gas-solid or fluid-solid flow are the Euler-Euler and Euler-Lagrange models. The paper presents models that describe a ship’s fluidized bed.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2016, 47 (119); 54-58
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models for prediction of rheological parameters in vinasses derived from sugar cane
Autorzy:
Chacua, L.M.
Ayala, G.
Rojas, H.
Agudelo, A.C.
Powiązania:
https://bibliotekanauki.pl/articles/25873.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
mathematical model
prediction
rheological parameter
vinasse
sugar-cane
ethanol production
rheological model
Źródło:
International Agrophysics; 2016, 30, 2
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hierarchical mathematical models of complex plants on the basis of power boiler example
Autorzy:
Stanisławski, W.
Rydel, M.
Powiązania:
https://bibliotekanauki.pl/articles/229880.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
once-through steam boiler
reduced hierarchical model
complex model reduction
Opis:
The methodology of hierarchical linearized mathematical models construction of complex plants to control purposes is presented in the paper. Thanks to the methodology, the one high order model (flat, one level model), is replaced by a collection of models, which are placed at different hierarchy levels. The models represent dynamic processes typical for each hierarchy level, and omit fast dynamic processes significant at lower levels. The higher is hierarchy level, the slower dynamic processes is described by the model and the lower is order of the models. Multi-level model structure gives possibility of dynamic properties analysis by application of aggregation procedure. One of the principal aggregation procedure is reduction of models at individual levels of hierarchical structure. Such approach enables creating a reduced hierarchical model including a collection of models at every level of hierarchy, characterized by various adequacy scopes and accuracy of the plant features approximation. The paper presents methodology of hierarchical complex plants models creation on the example of evaporator of the BP-1150 boiler. Each of the subsystem at individual level of model hierarchy is a multi-input and multi-output causal systems.
Źródło:
Archives of Control Sciences; 2010, 20, 4; 381-416
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Digital Fabrication of Mathematical Models via Low-Cost 3D FDM Desktop Printer
Autorzy:
Gür, Y.
Powiązania:
https://bibliotekanauki.pl/articles/1401922.pdf
Data publikacji:
2015-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
01.50.H-
02.60.Cb
07.05.Tp
81.20.Hy
Opis:
Additive manufacturing technology is developed throughout the 1980's and 1990's. This technology makes the realization of mathematical models much easier. The challenge focused is here to fabricate real objects from very complex mathematical models by using a low-cost 3D fused deposition modeling desktop printer. Thus this brings the intangible mathematical expressions to life. In this study it is illustrated that complex mathematical expressions are not only numbers and symbols but also they are real life objects. In the examples, some mathematical functions such as Möbius strip, Schwartz functions and their boundary conditions are introduced and then digitally fabricated. This work shows that how complex functional mathematical models that cannot be manufactured with classical engineering methods or very difficult to produce can be fabricated by using a 3D FDM desktop printer.
Źródło:
Acta Physica Polonica A; 2015, 128, 2B; B-100-B-102
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Challenges of Incorporating Realistic Simulations of Marine Protists in Biogeochemically Based Mathematical Models
Autorzy:
Davidson, Keith
Powiązania:
https://bibliotekanauki.pl/articles/763796.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Jagielloński. Wydawnictwo Uniwersytetu Jagiellońskiego
Tematy:
Mathematical modelling, protists, NPZD models, PFT models, trait based models, IBM models
Opis:
Protists are key components of marine microbial communities and hence of the biogeochemical mathematical models that are used to study the interaction between organisms, and the associated cycling of carbon and other nutrients. With increased computing power, models of microbial communities have markedly increased in complexity in the last 20 years, from relatively simple single nutrient currency, nutrient-phytoplankton-zooplankton-detritus (NPZD) models to plankton functional type (PFT) or trait based models of multiple organisms, or individual based models (IBMs) of specific organisms. However, our recognition, if not parameterisation, of the physiological processes that underpin both autotrophic and heterotrophic protist nutrition and growth arguably have increased faster than our modelling capability, generating a wealth of new modelling challenges. This paper therefore reviews historical development, current capability, and the future directions and challenges in protist based mathematical modelling.
Źródło:
Acta Protozoologica; 2014, 53, 1
1689-0027
Pojawia się w:
Acta Protozoologica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza modeli matematycznych bilansu populacji komórek
Analysis of mathematical models of cell population balance
Autorzy:
Cudak, M.
Bitenc, M.
Powiązania:
https://bibliotekanauki.pl/articles/2070507.pdf
Data publikacji:
2009
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
bilans populacji
model matematyczny
population balance
mathematical model
Opis:
Procesy biochemiczne wymagają specyficznego modelowania matematycznego. W pracy przeanalizowano budowę modeli stosowanych do opisu układów biologicznych. Ponadto przedstawiono przykłady dostępnych w literaturze modeli bilansu populacji komórek, różniących się strukturą.
Biochemical processes require specific mathematical modeling. The structure of available in literature models, used in the description of biological systems was analysed in this paper. Moreover, examples of cell population balance models of various structure were considered.
Źródło:
Inżynieria i Aparatura Chemiczna; 2009, 3; 36-37
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of the mathematical models of distillation equilibria for designing the differential distillation process
Autorzy:
Sobczak, E.
Ringel, T.
Łataś, R.
Powiązania:
https://bibliotekanauki.pl/articles/346973.pdf
Data publikacji:
2013
Wydawca:
Politechnika Bydgoska im. Jana i Jędrzeja Śniadeckich. Wydział Technologii i Inżynierii Chemicznej
Tematy:
colorants
asymmetric metal complexes
heteroleptic complexes
resistance to UV radiation
acetylacetone
Opis:
This paper presents the development of mathematical models for positive and negative azeotropes in the range of the more volatile concentrations component: x∈[0; az] ∨ [az; 1]. The coefficients of these models, which, on their basis, were determined the relative volatility of α and the azeotrope concentration az, defined with the high accuracy (R2∈[0,926; 0,999]) and presented them to the table for all subjects of distillation systems. Based on these relationships, the integration of the mass balance equations of the distillation differential process d(Sx)=ydS was carried out and determined the dependence of the distillate obtained from 1 mole of pig iron D/S0 from the α, az coefficients and xw, xs concentrations. Based on these dependencies, charts D/S0 were prepared from predefined by the authors parameter t=[0,05; 0,25; 0,5; 0,75] which is the change in the concentration of pig iron in the process of concentration. Dependencies, presented for distillation balances of positive and negative azeotrope, in the tested ranges, for similar values of α, have the same mileage. The calculations were made for the 126 distillation systems.
Źródło:
Ars Separatoria Acta; 2012-2013, 9/10; 103-116
1731-6340
Pojawia się w:
Ars Separatoria Acta
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three-dimensional mathematical models illustrated by objects from the collections of the Jagiellonian University Museum
Autorzy:
Maślanka, Krzysztof
Rodzeń, Jacek
Wyka, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/783456.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Umiejętności
Tematy:
mathematical models, Felix Klein, didactics of mathematics, Museum of the Jagiellonian University
modele matematyczne, Felix Klein, dydaktyka matematyki, Muzeum UJ
Opis:
This paper presents examples of mathematical models which have almost passed into oblivion, yet a few decades ago still played a significant role in the teaching of mathematics. In the late nineteenth century such devices started to be produced on a large scale for schools and universities. The Jagiellonian University Museum has three such models in perfect condition in its collections.
W artykule podajemy przykłady modeli matematycznych, obecnie niemal zapomnianych, które jeszcze kilkadziesiąt lat temu odgrywały wielką rolę w dydaktyce matematyki. Z końcem XIX wieku powstała prężna produkcja tych modeli na użytek szkół i uczelni. W Muzeum UJ zachowały się w doskonałym stanie trzy takie modele.
Źródło:
Studia Historiae Scientiarum; 2019, 18
2451-3202
Pojawia się w:
Studia Historiae Scientiarum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modele matematyczne dla danych proporcjonalnych
Математические модели для пропорциональных данных
Mathematical models for proportional data
Autorzy:
Oktaba, W.
Mikos, H.
Powiązania:
https://bibliotekanauki.pl/articles/741324.pdf
Data publikacji:
1970
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Źródło:
Applicationes Mathematicae; 1969-1970, 11, 2; 151-172
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of mathematical models for vibrations of one dimensional environments with considering nonlinear resistance forces
Autorzy:
Pukach, P.
Sokhan, P.
Stolyarchuk, R.
Powiązania:
https://bibliotekanauki.pl/articles/410895.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
mathematical model
nonlinear vibrations
nonlinear boundary value problem
Galerkin method
nonlinear elastic properties
Opis:
In this paper we consider important classes of one dimensional environments, bending stiffness of which can be neglected. It is impossible to apply approximate analytical method of solution of mathematical models of dynamic processes. So justification of existence and uniqueness of solutions, carried out a qualitative their evaluation, based on numerical analysis are considering in this paper. Also the features of dynamic processes of some of examined class of systems are analyzed. Methods of qualitative study of oscillations for restricted and unrestricted bodies under the influence of the resistance forces, described in this paper are based on the general principles of the theory of nonlinear boundary value problems – Galerkin method and the method of monotonicity. Scientific novelty consists in generalization these methods of studying for nonlinear problems at new classes of oscillating systems, justification of solution correctness for specified mathematical models that have practical application in real engineering vibration systems.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2016, 5, 1; 97-102
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Continuous mathematical models of airlift bioreactors: Families, affinity, diversity and modelling for single-substrate kinetics
Autorzy:
Grzywacz, R.
Powiązania:
https://bibliotekanauki.pl/articles/185530.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bioreaktor powietrzny
modelowanie matematyczne
symulacja
reaktor wielofazowy
airlift bioreactor
single-substrate kinetics
mathematical modelling
simulation
multiphase reactor
Opis:
This paper presents a method of describing an airlift bioreactor, in which biodegradation of a carbonaceous substrate described by single-substrate kinetics takes place. Eight mathematical models based on the assumption of liquid plug flow and axial dispersion flow through the riser and the downcomer in the reactor were proposed. Additionally, the impact of degassing zone with assumed complete mixing on the obtained results was analyzed. Calculations were performed for two representative hydrodynamic regimes of reactor operation, i.e. with the presence of gas bubbles only within the riser and for complete gas circulation. The conclusions related to the apparatus design and process performance under sufficient aeration of the reaction mixture were drawn on the basis of the obtained results.
Źródło:
Chemical and Process Engineering; 2012, 33, 2; 291-309
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelowanie niepewności w opisie matematycznym układu dynamicznego
Uncertainty modelling for mathematical models of dynamical systems
Autorzy:
Orłowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/152500.pdf
Data publikacji:
2007
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
układy niepewne
analiza niepewności
model matematyczny
układy dynamiczne
uncertainty analysis
uncertain systems
mathematical modeling
dynamical systems
Opis:
W artykule przedstawiono źródła i typy zaburzeń oraz niepewności występujących w układach dynamicznych, oraz szczegółowo opisano sposoby wprowadzania jej do modelu matematycznego układu. W ramach niniejszej pracy przeanalizowano sześć struktur niepewności: addytywną, w sprzężeniu zwrotnym wokół obiektu oraz multiplikatywną i w sprzężeniu zwrotnym zarówno na wejściu jak i wyjściu układu.
Mathematical modelling of uncertainty in dynamical systems is presented in the paper. Sources of uncertainties and perturbations are analysed. Perturbations are classified in four different classes. Uncertainty can be modelled using six different perturbation structures in the model: additive, subtractive, pre-, post- multiplicative, pre- and post- divisional. Properties of all analyzed structures are derived as well as upper bounds for analyzed perturbations.
Źródło:
Pomiary Automatyka Kontrola; 2007, R. 53, nr 2, 2; 12-15
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models of a pneumatic cascade and pneumatic membrane actuator described with a fractional calculus
Autorzy:
Luft, M.
Łukasik, Z.
Pietruszczak, D.
Powiązania:
https://bibliotekanauki.pl/articles/1841598.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
pneumatic cascade
pneumatic membrane actuator
fractional calculus
mathematical model
Matlab
bode plot
Matlab-Simulink
industrial automation
Opis:
The paper presents the analysis of dynamic properties of pneumatic systems such as: cascade connection of membrane pressure transmitters and a pneumatic membrane actuator by means of differential equations of integer and non-integer order. The analyzed systems were described from the time perspective by means of step response, and in terms of frequency with the help of the Bode plot, i.e. logarithmic magnitude and phase responses. Each response was determined using differential equations of non-integer order. To determine the responses, the interactive Simulink package was an irreplaceable programming tool built on the basis of the MATLAB program, which enables the analysis and synthesis of continuous dynamic systems.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2020, 14, 3; 643-648
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models of particle size distribution in simulation analysis of high-pressure grinding roll operations
Autorzy:
Saramak, D.
Powiązania:
https://bibliotekanauki.pl/articles/110253.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
HPGR
comminution
particle size distribution
ore processing
Opis:
The high-pressure grinding roll (HPGR) technology is currently one of the most efficient methods of hard ore comminution from the scope of the energy consumption. Throughput and energetic models of performance are quite well developed, but technological models predicting the comminution effects still needs an in-depth research. In the paper author presents the method of modeling of HPGR products’ particle size distribution by using suitable mathematical models. A basis of the HPGR perfor-mance assessment and HPGR-based crushing circuits design is a product’s particle size distribution. In order to precisely determine the particle size distribution of a HPGR product, parameters of product’s particle size distributions should be conditional on the main technical parameters of the roller press like operating pressure and the speed of rolls. The most accurate approximation of a distribution of size parti-cle appears to be Weibull’s truncated distribution and it is possible to obtain significant relationships between the approximation formula and the value of operating pressure, or feed characteristics. It makes possible a determination of mass recoveries of the product’s respective size fractions and the productivity planning. Instead of pressure, the other HPGR operating parameters can be applied, but the pressure value appears to produce the most relevant relationship. A determination of HPGR product’s particle size dis-tribution is a basis of the press operation simulation analysis.
Źródło:
Physicochemical Problems of Mineral Processing; 2013, 49, 1; 121-131
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models use to yield prognosis of perennials on marginal land according to fertilisers doses
Autorzy:
Hryniewicz, Marek
Strzelczyk, Maria
Helis, Marek
Paszkiewicz-Jasińska, Anna
Steinhoff-Wrzesniewska, Aleksandra
Roman, Kamil
Powiązania:
https://bibliotekanauki.pl/articles/2048530.pdf
Data publikacji:
2021
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
biomass
cup plant
fertiliser
Jerusalem artichoke
mathematical modelling
nitrogen
willowleaf sunflower
yield
Opis:
Models describe our beliefs about how the world functions. In mathematical modelling, we translate those beliefs into the language of mathematics. Mathematical models can yield prognose on the base of applied fertiliser dose. In this work results of finding yield mathematical model according to fertiliser (nitrogen) dose for perennials (willowleaf sunflower Helianthus salicifolious, cup plant Silphium perfoliatum and Jerusalem artichoke Helianthus tuberosus) on marginal land are presented. Models were described as normalised square equations for dependence between yield and fertiliser doses. Experiments were conducted in lisymeters and vases for willowleaf sunflower and cup plant. For Jerusalem artichoke experiments were done in vases only. All experiments have been doing during two years (2018 and 2019) for different fertilisers doses (45, 90 and 135 kg N∙ha-1) in three repetitions. From simulations maximal yield could be achieved for following fertiliser doses – willowleaf sunflower 104 kg N∙ha-1, cup plant 85 kg N∙ha-1 and Jerusalem artichoke 126 kg N∙ha-1.
Źródło:
Journal of Water and Land Development; 2021, 51; 233-242
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of the Mathematical models of the integral drilling indices based on the Dimensional analysis
Autorzy:
Moisyshyn, V.
Borysevych, B.
Yytyaz, O.
Gavryliv, Y.
Powiązania:
https://bibliotekanauki.pl/articles/299197.pdf
Data publikacji:
2014
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
axial static load on the well bottom-hole
angular speed of the drill bit rotation
mathematical model
mechanical drilling speed
average value of torque on the bit
energy intensity for the rock destruction process on the well bottom-hole
stiffness and damping of the drilling tools
Opis:
The dimensional analysis method was used to estimate the influence of the axial static load on the bottom-hole, angular speed of the drill bit rotation, stiffness, and damping of the drilling tools on the integral indices of well drilling. The mathematical models of the mechanical drilling speed, average values of torque on the bit, and energy consumption for the rock destruction process on the well bottom-hole were developed for two interlayers of the Vorotyshchenska formation with the hardness of 1440 and 2050 MPa.
Źródło:
AGH Drilling, Oil, Gas; 2014, 31, 3; 431-440
2299-4157
2300-7052
Pojawia się w:
AGH Drilling, Oil, Gas
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical Models and Computer Simulations of Aerial Spraying and Droplets Distribution in a Target Site
Autorzy:
Rowiński, Robert S.
Powiązania:
https://bibliotekanauki.pl/articles/36406214.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
Tematy:
agricultural aviation
aerial spraying
drift
Opis:
Mathematical models describing aerial spraying and the distribution of liquid droplets on a target were presented. Relationships based on “free models” with Gaussian distribution of droplet concentrations and “bound models” that account for the impact of disturbances in the velocity field behind agricultural aircraft were expanded, and the hybrid model too. The results of experimental studies were presented and compared with theoretical calculations. The “bound model” was found to be the most effective solution for describing the physical phenomena that accompany the aerial spraying process.
Źródło:
Transactions on Aerospace Research; 2019, 3 (256); 24-42
0509-6669
2545-2835
Pojawia się w:
Transactions on Aerospace Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Review of applied mathematical models for describing the behaviour of aqueous humor in eye structures
Autorzy:
Dzierka, M.
Jurczak, P.
Powiązania:
https://bibliotekanauki.pl/articles/265906.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
porous medium
Newtonian fluid
non-Newtonian fluid
couple stress fluid
generalized second grade fluid
Darcy’s rule
aqueous humor flow
intraocular pressure
glaucoma
porowatość
płyn nienewtonowski
jaskra
ciśnienie wewnątrzgałkowe
Opis:
In the paper, currently used methods for modeling the flow of the aqueous humor through eye structures are presented. Then a computational model based on rheological models of Newtonian and non-Newtonian fluids is proposed. The proposed model may be used for modeling the flow of the aqueous humor through the trabecular meshwork. The trabecular meshwork is modeled as an array of rectilinear parallel capillary tubes. The flow of Newtonian and non-Newtonian fluids is considered. As a results of discussion mathematical equations of permeability of porous media and velocity of fluid flow through porous media have been received.
Źródło:
International Journal of Applied Mechanics and Engineering; 2015, 20, 4; 757-772
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of mathematical model for the autonomous gliding delivery system
Autorzy:
Loroch, L.
Sibilski, K.
Żyluk, A.
Powiązania:
https://bibliotekanauki.pl/articles/235504.pdf
Data publikacji:
2006
Wydawca:
Wojskowy Instytut Techniczny Uzbrojenia
Tematy:
modele matematyczne
mathematical models
Opis:
For parafoil and payload aircraft, control is affected by changing the length of several rigging lines connected to the outboard side and rear of the parafoil leading to complex changes in the shape and orientation of the lifting surface. Flight mechanics of parafoil and payload aircraft most often employ a 6 or 9 DOF representation with the canopy modeled as a rigid body during flight. The effect of control inputs usually is idealized by the deflection of parafoil brakes on the left and right side of the parafoil. This work focused on description of a 9 DOF parafoil and payload aircraft simulation model.
Źródło:
Problemy Techniki Uzbrojenia; 2006, R. 35, z. 97; 149-162
1230-3801
Pojawia się w:
Problemy Techniki Uzbrojenia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Podpisy niezaprzeczalne - podpisy z dodatkową funkcjonalnością
Undeniable Signatures - Signatures with Additional Functionality
Autorzy:
Pośpiech, Ewa
Powiązania:
https://bibliotekanauki.pl/articles/590990.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Modele matematyczne
Mathematical models
Opis:
Today, the role of digital signatures becoming more and more significant. The signature provides authentication and integrity of a message but quite often other features like additional functionality is required from the signature. Because of that the algorithms used in ordinary signing are not sufficient, they need to be special algorithms with some additional characteristics. Undeniable signatures are a form of digital signature that have two distinctive features: the verification process is interactive (the signatures cannot be verified without signer's cooperation), a disavowal protocol allows to determine whether a given signature is a forgery. These signatures can be used, for example, to protect a software against unauthorized persons. The safety of these signatures is guaranteed by techniques of modern cryptography which is based on advanced mathematical tools and computer technology. The purpose of the article is to present selected schemes (protocols) of undeniable signatures (based on discrete log systems) such as Chaum-van Antwerpen protocol, Chaum-van Antwerpen protocol protecting against disavowal and a convertible undeniable signature protocol. Main definitions and theorems are presented and all described protocols are illustrated with examples.
Źródło:
Studia Ekonomiczne; 2013, 132; 67-79
2083-8611
Pojawia się w:
Studia Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison between mathematical models and artificial neural networks for prediction of sorption isotherm in rough rice
Autorzy:
Amiri-Chayjan, R.
Esna-Ashari, M.
Powiązania:
https://bibliotekanauki.pl/articles/24119.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Źródło:
International Agrophysics; 2010, 24, 1; 1-7
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena wpływu zmiennych objaśniających na zmienną zależną w metodzie rzutowania PPR
Determining the Influence of Predictor Variables on the Response Variable in the PPR Models
Autorzy:
Trzęsiok, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/593190.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Modele matematyczne
Mathematical models
Opis:
Projection Pursuit Regression (PPR) was introduced by J. Friedman and W. Stuetzle in 1981. It is one of the nonparametric regression methods. The benchmark studies show very often the superiority of PPR models over other nonparametric or classical regression models in terms of the test error. PPR produces a "black-box" prediction machine and it suffers from the lack of interpretation. Thus it seems to be an important issue to find the method for evaluating the influence of the predictor variables on the response. We present the procedure that might be used to examine the strength of the influence of every predictor variable on the response variable in Projection Pursuit Regression models.
Źródło:
Studia Ekonomiczne; 2013, 132; 104-114
2083-8611
Pojawia się w:
Studia Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modele matematyczne transmisji promieniowania przez komórkowe izolacje transparentne
Mathematical models of solar transmission through transparent insulation
Autorzy:
Grudzińska, M
Powiązania:
https://bibliotekanauki.pl/articles/362459.pdf
Data publikacji:
2011
Wydawca:
Instytut Fizyki Budowli Katarzyna i Piotr Klemm
Tematy:
izolacje transparentne
transmisja promieniowania słonecznego
transparent insulation
solar transmission
Opis:
W artykule porównano najczęściej stosowane modele transmisji promieniowania płyt komórkowych, wykorzystywanych jako izolacje transparentne. Przedstawiono także własny, zmodyfikowany sposób obliczeń który może służyć opracowywaniu algorytmów komputerowych modelujących własności płyt transparentnych.
The paper presents basic mathematical models of solar transmission through the transparent insulation. Comparison between models shows the importance of including the radiation scattering during the calculation procedures.
Źródło:
Fizyka Budowli w Teorii i Praktyce; 2011, T. 6, nr 4, 4; 21-26
1734-4891
Pojawia się w:
Fizyka Budowli w Teorii i Praktyce
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wyznaczenie okresu równowagi i stabilizacji długookresowej
Determination of the Period of Long-Term Equilibrium and Stability
Autorzy:
Janiga-Ćmiel, Anna
Powiązania:
https://bibliotekanauki.pl/articles/590057.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Modele matematyczne
Mathematical models
Opis:
The study examines the development of the Polish economy as well as the economies of selected European Union countries in the period from 1949 to 2006. Much space is devoted to a comparative analysis of the development economies in the countries concerned. Based on statistical data appropriate synthetic variables were set. Much space is devoted to the theory of the Johansen's method, to present the dependencies occurring in the dynamics of economic development in subsequent subperiods. The method allows for a comparative assessment of the dynamics of time series. The methods are adopted to examine the level of economic development, to determine the period of long-term equilibrium and stability.
Źródło:
Studia Ekonomiczne; 2013, 132; 35-44
2083-8611
Pojawia się w:
Studia Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of friction interaction and optimisation of detail surface hardening technologies using non-local mathematical models
Autorzy:
Lyashenko, B. A.
Stotsko, Z. A.
Kuzin, O. A.
Kuzin, M. O.
Mechnik, V. A.
Powiązania:
https://bibliotekanauki.pl/articles/366788.pdf
Data publikacji:
2020
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
friction
surface engineering
non-local mathematical model
optimisation
tarcie
inżynieria powierzchni
model matematyczny
optymalizacja
Opis:
Purpose: The aim of the work is to build physically sound engineering and design schemes that take into account the behaviour of polycrystalline metal systems under intense loads and allow optimization of surface treatment technologies to increase the operational reliability parameters of products. Design/methodology/approach: Using the approaches of thermodynamics, a methodological scheme is proposed, on the basis of which it is possible to optimize surface engineering technologies to increase the contact durability of details. Findings: It was found that the maximum increase in the durability of steel 40X13 (AISI 420) is achieved with thermocyclic ion nitriding in a cycle of ± 50°C, and the minimum with isothermal nitriding. Research limitations/implications: In this paper, the optimization of technological solutions to increase the contact durability of structural elements operating under prevailing power loads is given. Practical implications: Using the proposed mathematical relationships, optimal technological regimes of ion-plasma nitriding were established for various operating conditions, under which the maximum durability and wear resistance of 40X13 (AISI 420) steel are ensured. Originality/value: The paper proposes an approach to the formation of functionally gradient surface layers of steel with specified operational parameters when choosing optimal nitriding technology modes based on nonlocal mathematical models.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2020, 100, 1; 20-25
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical models for occupational injuries analysis at the enterprises of the state forestry committee of Ukraine
Autorzy:
Tysovsky, L.
Stepanyshyn, V.
Powiązania:
https://bibliotekanauki.pl/articles/972975.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
occupational injuries
correlation and regression analysis
methods of multifactor analysis
Opis:
The paper focuses on the mathematical models for the study of occupational injuries at the enterprises of the State Forestry Committee of Ukraine over a period of ten years. The major conditions and causes of the accidents have been indicated. The relationship between individual pairs of variables that influence occupational injuries has been determined on the basis of correlation and regression analysis. The correlation dependences of the frequency of occupational injuries on individual factors have been obtained. Using the methods of multifactor analysis, the relationship between the number of injuries and workers' occupations as well as types of works Has been established. The results obtained can be used for enhancing the efficiency of safety measures at the enterprises of for estry with the aim of reducing the rate of injury.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2014, 3, 2; 71-78
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical tests as the basis for formulating mathematical models of the opening delay of CIDI injectors
Autorzy:
Skowron, M.
Wisłocki, K.
Pielecha, I.
Powiązania:
https://bibliotekanauki.pl/articles/133943.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
diesel fuel
direct injection
injection delay
optical research
solenoid injector
piezoelectric injector
olej napędowy
wtrysk bezpośredni
opóźnienie wtrysku
badania optyczne
wtryskiwacz piezoelektryczny
wtryskiwacz elektromagnetyczny
Opis:
The main objective of this research was an attempt to evaluate the delay times of the actual needle opening of the diesel injectors in relation to the time of triggering the current control signals opening the solenoid and piezoelectric high-pressure injectors of diesel engines. The conducted tests take into account the variability of fuel injection pressure and backpressure prevailing in the operational chamber of the engine. To determine accurately the time of actual injection start, the optical tests analysing the image of the injector tip were used. Such high resolution images were obtained by high-speed recording with a frequency of 250 kHz (Dt = 0.004 ms). Based on a comparison of the results obtained, it was found that the maximum delay time of fuel injection for a piezoelectric diesel injector is about 12% shorter than for a solenoid injector. Experimentally obtained results of the injection time delay were used as a basis to formulate mathematical models describing the delay of the real fuel injection in relation to the signal controlling the opening of the diesel injectors. These models take into account the dependence of the injector reaction from the injection pressure and the backpressure in the operational chamber of the engine. The correctness of the obtained models is confirmed by acceptable values of the determination coefficient (for solenoid injector – 0.6, for piezoelectric injector – above 0.8 – for correlation of injection delay and backpressure).
Źródło:
Combustion Engines; 2017, 56, 4; 185-192
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ redukcji poziomu szumu losowego metodą najbliższych sąsiadów na wartość największego wykładnika Lapunowa
Effect of Reduction of Random Noise by Method of the Nearest Neighbors on the Value of the Largest Lyapunov Exponent
Autorzy:
Zeug, Katarzyna
Powiązania:
https://bibliotekanauki.pl/articles/592070.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Ekonomiczny w Katowicach
Tematy:
Modele matematyczne
Mathematical models
Opis:
Since the presence of noise in the data can significantly affect the characteristics of dynamic systems, the aim of the article will be to evaluate effect of reduction of random noise by method of the nearest neighbors on the value of the largest Lyapunov exponent. The test will be conducted on the basis of the economic time series, which consist of closing prices of companies listed on the Warsaw Stock Exchange and the daily exchange rates.
Źródło:
Studia Ekonomiczne; 2013, 132; 160-168
2083-8611
Pojawia się w:
Studia Ekonomiczne
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Construction and analysis of new mathematical models of the operation of ship propellers in different maneuvering modes
Autorzy:
Kryvyi, O.
Miyusov, M. V.
Kryvyi, M.
Powiązania:
https://bibliotekanauki.pl/articles/24201453.pdf
Data publikacji:
2023
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
ship propellers
curvilinear motion
mathematical models
hydrodynamic forces
hydrodynamic moments
wake fraction
thrust-deduction factor
drift angle
Opis:
The influence of the curvilinear movement of the ship on the operation of the propeller was studied. It is shown that even at small values of the drift angle and the angular velocity of the vessel, the transverse component of the force on the propeller and the moment are non-zero and cannot be neglected. The existing and proposed new effective mathematical models of the longitudinal and transverse components of force and moment caused by the operation of the ship's propeller are analyzed. Simple expressions for the coefficients of the propeller thrust and the moment on the propeller shaft, the wake fraction, the thrust-deduction factor, and the flow straightening factor on the propeller at any drift angles and angular velocity are obtained. Numerical analysis of the obtained dimensionless components of forces and moments caused by the operation of the propeller is carried out, and their adequacy is shown. It is shown how the specified parameters change for all possible values of the drift angle and angular velocity. For a few commercial vessels of various types, technical characteristics and calculated dynamic parameters are given for the construction of mathematical models of propeller operation during curvilinear movement of the vessel.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2023, 17, 1; 95--102
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-50 z 244

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