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Search results for: accelerator modes
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A calibration model for gas sensor array in varying environmental conditions
PublicationAbstract: Gas-analyzing systems based on gas sensors, commonly referred to as electronic noses, are the systems which enable the recognition of volatile compounds in their working environment and provide the on-line results of analysis. The most commonly used type of sensors in such systems is semiconductor gas sensors. They are considered to be the most reliable in the long-term applications (more than 1 year), however,...
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Virtual Engineering Objects (VEO): Designing, Developing and Testing Models
PublicationIn this article, the development and implementation of the concept of Virtual Engineering Object (VEO) is described. A VEO is a computerized real world representation of an engineering object. VEO will act as a living representation of the object capable of adding, storing, improving and sharing knowledge through experience, in a way similar to an expert of that object. In this paper, it is shown through test models how the concept...
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A quasi-2D small-signal MOSFET model - main results
PublicationDynamic properties of the MOS transistor under small-signal excitation are determined by kinetic parameters of the carriers injected into the channel, i.e., the low-field mobility, velocity saturation, mobility at the quiescent-point (Q-point), longitudinal electric field in the channel, by dynamic properties of the channel, as well as by an electrical coupling between the perturbed carrier concentration in the channel and the...
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Distributed state estimation using a network of asynchronous processing nodes
PublicationWe consider the problem of distributed state estimation of continuous-time stochastic processes using a~network of processing nodes. Each node performs measurement and estimation using the Kalman filtering technique, communicates its results to other nodes in the network, and utilizes similar results from the other nodes in its own computations. We assume that the connection graph of the network is not complete, i.e. not all nodes...
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Peculiarities associated with testing polyetheretherketone (PEEK) in a model rolling contact
PublicationPolyetheretherketone (PEEK) was investigated using a modified version of the four-ball tester in which the upper forth ball was replaced by a cone in such a way that kinematics of the four-ball configuration were fully preserved. Rotation of the cone enforced orbiting and rolling of the ceramic balls around the polymer cup. The results produced some unexpected peculiarities in the wear of ceramic balls which, in principle, should...
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Model dynamicznego balastowania małego morskiego obiektu typu stealth
PublicationW artykule przedstawiono podstawowe problemy związane z modelowaniem głównych cech decydujących o trudno-wykrywalności małego obiektu na etapie projektu koncepcyjnego. Metoda badawcza oparta jest na ocenie zachowania się obiektu i ocenie ryzyka wypadku. W artykule skupiono się głównie na przedstawieniu modelu matematycznego opisującego model dynamicznego balastowania małego morskiego obiektu typu stealth. Przedstawione w artykule...
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On the Equations of the Surface Elasticity Model Based on the Theory of Polymeric Brushes
PublicationMotivating by theory of polymers, in particular, by the models of polymeric brushes we present here the homogenized (continual) two-dimensional (2D) model of surface elasticity. A polymeric brush consists of an system of almost aligned rigid polymeric chains. The interaction between chain links are described through Stockmayer potential, which take into account also dipole-dipole interactions. The presented 2D model can be treated...
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A material model of asphalt mixtures based on Monte Carlo simulations
PublicationThe paper aims to numerically reflect mineral-asphalt mixture structure by a standard FEM software. Laboratory test results are presented due to bending tests of circular notched elements. The result scatter is relatively high. An attempt was made to form a random aggregate distribution in order to obtain various results corresponding to laboratory tests. The material structure calibration, its homogenization and finite element...
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Importance of model tests in design and operation of watercraft for example CTO
PublicationShip Hydromechanics Division is a specialized research and development department of Ship Design and Research Centre conducting tests and research in the field of hydromechanics, connected with design and operation of ships and other floating structures, in scope of: predictions, numerical analyses, designs of - hull shape optimized with respect to the ship’s functions with the application of modern design tools, screw propellers...
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Distributed state estimation using a network of asynchronous processing nodes
PublicationWe consider the problem of distributed state estimation of continuous-time stochastic processes using a~network of processing nodes. Each node performs measurement and estimation using the Kalman filtering technique, communicates its results to other nodes in the network, and utilizes similar results from the other nodes in its own computations. We assume that the connection graph of the network is not complete, i.e. not all nodes...
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A Concept of Using Knowledge Models to Secure Intellectual Capital in Enterprise
PublicationWithout a doubt, knowledge has become the most important resource for all companies in the world. Knowledge extended of our own observations and practice is being called experience. With the increase of knowledge and gained experience, the individual becomes more and more valuable employee in terms of business. The above mentioned knowledge can be gained only by self-improvement, which requires time and other necessary elements...
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MACRO MODEL OF SEAT BELT USE BY CAR DRIVERS AND PASSENGERS
PublicationThe article presents some problems of seat belt use by car drivers and passengers. It looks in particular at seat belt use and effectiveness in selected countries. Next, factors of seat belt use are presented and methodology of model development. A macro model of seat belt use is presented based on data from around fifty countries from different continents.
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Wirtualny model zbiorników z wodą w sterowniku PLC
PublicationModele obiektów rzeczywistych otrzymuje się na różnorodne sposoby i wykorzystuje w różnorodnych celach. Do badania obiektów automatyki stosuje się najczęściej programy komputerowe, np.: Matlab-Simulink, Scilab, GNU Octave, itp. Można również stosować pamięć operacyjną sterowników [1, 2]. W referacie przedstawiono opis wirtualnego modelu dwóch połączonych zbiorników z wodą w sterowniku PLC. Proste przekształcenia matematyczne pozwalają...
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A Quasi-2D MOSFET Model — 2D-to-Quasi-2D Transformation
PublicationA quasi-two-dimensional (quasi-2D) representation of the MOSFET channel is proposed in this work. The representation lays the foundations for a quasi 2D MOSFET model. The quasi 2D model is a result of a 2D into quasi 2D transformation. The basis for the transformation are an analysis of a current density vector field and such phenomena as Gradual Channel Detachment Effect (GCDE), Channel Thickness Modulation Effect (CTME), and...
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A Model-Driven Solution for Development of Multimedia Stream Processing Applications
PublicationThis paper presents results of action research related to model-driven solutions in the area of multimedia stream processing. The practical problem to be solved was the need to support application developers who make their multimedia stream processing applications in a supercomputer environment. The solution consists of a domain-specific visual language for composing complex services from simple services called Multimedia Stream...
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Examining Quality of Hand Segmentation Based on Gaussian Mixture Models
PublicationResults of examination of various implementations of Gaussian mix-ture models are presented in the paper. Two of the implementations belonged to the Intel’s OpenCV 2.4.3 library and utilized Background Subtractor MOG and Background Subtractor MOG2 classes. The third implementation presented in the paper was created by the authors and extended Background Subtractor MOG2 with the possibility of operating on the scaled version of...
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A quasi-2D small-signal MOSFET model - main results
PublicationMain results stemming from a new quasi 2D non-quasi-static small-signal four-terminal model of the MOSFET are presented in this work. The model is experimentally verified up to 30 GHz.
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Launching of steel bridge girder. Application of nonlinear shell models
PublicationThe paper describes the final technology of launching the steel bridge superstructure. The original technology failed in the first construction stage. Local damage of steel webs caused by plastic buckling stopped the procedure. In the effect of damage a new consulting team was employed to solve the problem and redesign a technology of constructing. The key element of the new solution was developed with great help of non-linear...
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Antropoidalny Model Inteligentnego Systemu Decyzyjnego dla Jednostek Autonomicznych
PublicationGłównym celem pracy jest opracowanie modelu procesów psychologicznych -- od momentu otrzymania bodźca do momentu podjęcia adekwatnej reakcji -- zachodzących w mózgu człowieka (psychologia poznawcza), oraz teorii motywacji (potrzeb, popędów i emocji). Model, zaprezentowany w pracy nazwany Inteligentnym Systemem Decyzyjnym (ISD), może mieć zastosowanie w systemie sterowania jednostką autonomiczną (agentem). W rozprawie rozważa się...
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Investigation of Transmit and Receive Characteristics of Laboratory Model for the Parametric Echosounder
PublicationInvestigation and operation of devices based on nonlinear interaction of high-intensity waves have been carried out for several decades. However, it is still a new tool to study the properties of the water environment and especially the upper layers of the seabed. This paper describes the results of tests of the new device that is intended to be applied for sounding underwater areas. The device has been designed and built in collaboration with...
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Model of heat transfer in the stagnation point of rapidly evaporating microjet
PublicationThe paper presents investigation into the single water microjet surface cooling producing evaporating film. Reported tests were conducted under steady state conditions. Experiments were conducted using the nozzle size of 70 and 100 mikrometer respectively. In the course of investigations obtained were experimental relations between heat flux and wall superheating. It was proved that the phenomenon is similar to that of pool boiling...
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Dynamic host configuration protocol for IPv6 improvements for mobile nodes
PublicationIn wireless networks mobile clients change their physical location, which results in changing point of attachment to the network. Such handovers introduce unwanted periods, when node does not have communication capabilities. Depending on many conditions, such events may require reconfiguration of layer 2 (e.g. IEEE 802.16) or both 2 and 3 layers (IPv6). This paper investigates delays introduced in the latter type of handover. IPv6...
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A Hyperdense Semantic Domain for Discontinuous Behavior in Physical System Models
PublicationMultiple time models have been proposed for the formalization of hybrid dynamic system behavior. The superdense notion of time is a well-known time model for describing event-based systems where several events can occur simultaneously. Hyperreals provide a domain for defining the semantics of hybrid models that is elegantly aligned with first principles in physics. This paper discusses the value of both time models and shows how...
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An evaluation of effectiveness of fuzzy logic model in predicting the business bankruptcy
PublicationW artykule sprawdzono skuteczność pojedynczego modelu logiki rozmytej w prognozowaniu ryzyka upadłości przedsiębiorstw w Polsce. W badaniach wykorzystano wartości 14 wskaźników finansowych oraz ich dynamikę zmiany między pierwszym a drugim, drugim a trzecim oraz trzecim a czwartym rokiem objętymi analizą. We wnioskach omówiono różnicę w skutecznościach modelu uzyskanego na wartościach statycznych oraz dynamicznych wskaźników finansowych....
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Model instalacji napowietrzającej dla celów sterowania - studium przypadku
PublicationBiologiczne oczyszczanie ścieków stanowi podstawową grupę procesów w oczyszczalni ścieków. Jednym z nich jest napowietrzanie ścieków realizowane z wykorzystaniem instalacji napowietrzającej. Powszechnie uważa się go za jeden z najważniejszych i najdroższych procesów w oczyszczalni ścieków. Model procesu jest potrzebny do szczegółowej jego analizy, zbadania możliwości modyfikacji istniejących lub zastosowania innych metod sterowania....
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Model rozwoju kompetencji kierowniczych w małych firmach informatycznych
PublicationW referacie przedstawiono wyniki badania nad rozwojem kompetencji kierowniczych w małych firmach IT. Omówiono badania ankietowe służące określeniu ważności poszczególnych kompetencji z modelu ICB organizacji IPMA dla małych firm. Na podstawie wyników ankiet wyróżniono trzy klasy ważności kompetencji kierowniczych dla typowej małej firmy IT, którą scharakteryzowano. Opracowana klasyfikacja może być podstawą rozwiązania doradczego...
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Reduced order models in computational electromagnetics (in memory of Ruediger Vahldieck)
PublicationThis paper reviews research of Ruediger Vahldieck's group and the group at the Gdansk University of Technology in the area of model order reduction techniques for accelerating full-wave simulations. The applications of reduced order models to filter design as well as of local and nested(multilevel) macromodels for solving 3D wave equations and wave-guiding problems using finite difference and finite element methods are discussed.
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An example of the fuzzy internet mortgage market sub-models implementation
PublicationPrzedstawiono implementacje rozmytego modelu do wspomagania zarządzania internetowym rynkiem kredytów hipotecznych
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Transmission Quality in MC-CDMA Radio Interface with Turbo Codes
PublicationMulti-Carrier Code Division Multiple Access techiques is a combination of two radio access techniques: Code Division Multiple Access (CDMA) and Orthogonal Frequency-called Division Multiplexing (OFDM) and has the advantages of both techniques. The paper presents the design of transmitter and receiver for MC-CDMA radio interface and the simulation results of the transmission quality in AWGN channel.
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Simulations of fracture in concrete elements using continuous and discontinuous models
PublicationArtykuł przedstawia wyniki symulacji MES w elementach betonowych przy zastosowaniu modeli ciągłych i nieciągłych. Stosując modele ciągłe symulowano proces lokalizacji odkształceń. Stosując modele nieciągłe symulowano proces zarysowania. Obliczenia wykonano dla różnych typów obciążeń.
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Mechanical model of fascia-implant structure. Finite element simulation.
PublicationPraca dotyczy modelowania i symulacji syntetycznych implantów chirurgicznych stosowanych w leczeniu przepulin brzusznych metodą laparoskowpową. Prponowane są modele matematyczne a ich prawidłowość weryfikowana jest na podstawie badań doświadczalnych zachowania się modeli fizycznych wszczepionych implantów pod wpływem obciążeń wynikających z fizjologii człowieka. Nakreślona jest metodologia oceny trwałości połączenia siatki chirurgicznej...
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A literature review on computational models for laminated composite and sandwich panels
PublicationW artykule przedstawiono przegląd modeli obliczeniowych stosowanych w analizie laminowanych powłok kompozytowych i sandwiczowych. W przeglądzie uwzględniono ponad 200 pozycji literatury traktujących o modelach teoretycznych dla płyt i powłok wielo-warstowych oraz/lub o implementacjach numerycznych różnych modeli obliczeniowych. Jako podstawową konkluzję z dokonanego przeglądu, należy uznać, że nie istnieje jeden uniwersalny model...
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A simple model for automated negotiations over collaboration agreements in ebXML
PublicationPoważnym ograniczeniem w upowszechnianiu standardu ebXML(elektronicznego obiegu dokumentów)jest możliwość występowania konfliktu pomiędzy partnerami transakcji. W artykule zaproponowano prosty mechanizm umożliwiający rozstrzyganie takich konfliktów w drodze automatycznie realizowanych negocjacji, którego wdrożenie pozwoli znacznie rozszerzyć zakres stosowania standardu ebXML.
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Conception of interactive information and decision support system - model and evaluation
PublicationThis article presents conception of interactive information and decision support system for urban and industrial air quality management. The emphasis of the project is on real-time analysis and multi-media information, and support of distributed and mobile clients through the Internet.
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Model of heat transfer in the stagnation point of rapidly evaporating microjet
PublicationThe paper presents investigation in the single water microjet surface cooling producing evaporating film. Reported tests were conducted under steady state conditions. It was proved that the phenomenon is similar to that of pool boiling. Results of experiments were compared with predictions by the model showing a good consistency.
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Comparison of the Efficiency of Turbo Codes with Mechanisms of Reducing the Number of Iterations
PublicationThe paper presents the construction of encoders and decoders turbo codes with different number of states. Simulation results of the transmission quality of the turbo codes were presented. Decoders for turbo codes have worked with a fixed number of iterations and with the mechanisms reducing the number of iterations. Data were transmitted in Outdoor to Indoor & Pedestrian B environment for data rate 384 kbps. The SOVA algorithm...
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Frequency-dependent coupling model for microwave band-pass filter
PublicationThe goal of this work was to create a circuit model which represents frequency-dependent coupling between microwave resonators. Our models are designed for in-line filters. The frequency-dependent coupling enables one to realize a transmission zero which is not possible in classical approach with frequency independent inverters. In addition, the proposed model allows us to observe out-of-band behavior, e.g. spurious resonance....
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Modified linear viscoelastic model of earthquake-induced structural pounding
PublicationIn recent times, earthquake-induced structural pounding has been intensively studied through the use of different impact force models. The numerical results obtained from the previous studies indicate that the linear viscoelastic model is relatively simple and accurate in modeling pounding-involved behavior of structures during earthquakes. The only shortcoming of the model is a negative value of the pounding force occurring just...
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CONTROL OF THE WAVES IN A TOWING TANK WITH THE USE OF A BLACK-BOX MODEL
PublicationThe paper describes an adaptive control system of the waves, implemented in the Ship Design and Research Centre, CTO S.A. The purpose of generating the waves in the towing tank is the modelling of the environmental conditions during hydrodynamic model tests. The tests are performed on scale models of towed or free running ships, anchored structures like oil rigs or bottommounted structures, e.g. wind turbines. In the towing tank...
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NUMERICAL MODEL OF PLASTIC DESTRUCTION OF THICK STEEL STRUCTURAL ELEMENTS
PublicationIn the shipbuilding industry, the risk of brittle fracture of the structure is limited by using certified materials with specified impact strength, determined by the Charpy method (for a given design temperature) and by supervising the welding processes (technology qualification, production supervision, non-destructive testing). For off-shore constructions, classical shipbuilding requirements may not be sufficient. Therefore, the...
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Infiltration in a double-porosity medium: Experiments and comparison with a theoretical model
PublicationThis paper presents experimental verification of the mathematical model of unsaturated flow in double‐porosity soils developed by the asymptotic homogenization method. A series of one‐dimensional infiltration experiments was carried out in a column filled with a double‐porosity medium composed of a mixture of sand and sintered clayey spheres arranged in a periodic manner. The unsaturated hydraulic properties of each porous material...
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Dynamics of a simplified HPT model in relation to 24h TSH profiles
PublicationWe propose a simplified mathematical model of the hypothalamus-pituitary-thyroid (HPT) axis in an endocrine system. The considered model is a modification of the model proposed by Mukhopadhyay and Bhattacharyya in [10]. Our system of delay differential equations reconstructs the HPT axis in relation to 24h profiles of human in physiological conditions. Homeostatic control of the thyroid-pituitary axis is considered by using...
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Variable length sliding models for banking clients face biometry
PublicationAn experiment was organized in 100 bank branches to acquire biometric samples from nearly 5000 clients including face images. A procedure for creating face verification models based on continuously expanding database of biometric samples is proposed, implemented, and tested. The presented model applies to circumstances where it is possible to collect and to take into account new biometric samples after each positive verification...
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From Sequential to Parallel Implementation of NLP Using the Actor Model
PublicationThe article focuses on presenting methods allowing easy parallelization of an existing, sequential Natural Language Processing (NLP) application within a multi-core system. The actor-based solution implemented with the Akka framework has been applied and compared to an application based on Task Parallel Library (TPL) and to the original sequential application. Architectures, data and control flows are described along with execution...
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The use of mathematical models for diagnosis of activated sludge systems in WWTP
PublicationIn this study diagnosis of activated sludge systems in wastewater treatment plant (WWTP) was investigated. Diagnosis of technical objects can be realized in many ways. One of the divisions of the diagnostic methods include modelling with or without a model of the object. The first of these is the analysis of the symptoms for which, based on the parameter values, the abnormality in the diagnosed objects are sought. Another way is...
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Comparative analysis of different numerical models of a steel radial gate
PublicationHydrotechnical structures are important components in water management system and general flooding safety. Their reliability should be ensured since potential damage might lead to catastrophic consequences. Weir gates are considered to be highly vulnerable elements of each hydro power plant, with regard to its dynamic resistance. The aim of the paper is to compare different numerical models and their influence on the results of...
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Reprezentation of mechanic hysteresis in a railway track using the Preisach model
PublicationThis paper presents an implementation of the classic scalar Preisach model to describe the hysteresis phenomenon created in a railway track subjected to lateral (in the horizontal plane) displacements. The principles of the Preisach theory and the scalar mathematical model of the mechanical hysteresis that is based on statistically distributed modified hysteresis operators are briefly presented. This article presents the characteristic...
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MODEL OF MULTILEVEL STOCHASTIC ANALYSIS OF ROAD SAFETY ON REGIONAL LEVEL
PublicationIn this paper multilevel approach to the issue of road safety level on the road network of European regions, classified as NUTS 2 in statistical databases of the European Union, has been presented. Following the pattern of many publications on road safety it has been assumed that the risk calculated as the number of death casualties in road accidents per 100,000 inhabitants of a given region has Poisson distribution. Therefore,...
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Bayesian estimation of the parameters in safely and reliability models for the subjective priors.
PublicationRozważono problem estymacji nieznanych charakterystyk niezawodnościowych za pomocą nieparametrycznych metod Bayesowskich. W wielu przypadkach opinie ekspertów są jedynym źródłem danych apriorycznych w modelach Bayesowskich. Celem uzyskania subiektywnych prawdopodobieństw apriorycznych zastosowano pewne metody ekspertowe. W oparciu o proces Dirichleta, który jest kluczowym pojęciem w teorii Fergusona, zostały skonstruowane...
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Parametryczny, przestrzenny model silnika asynchronicznego - aplikacja programu AutoCad.
PublicationW pracy przedstawiono program komputerowy, który w sposób kompleksowy wspomaga użytkownika w automatycznym narysowaniu trójwymiarowego modelu silnika asynchronicznego klatkowego. Model maszyny jest parametryczny, co oznacza, że użytkownik definiuje topologię poszczególnych elementów na podstawie: wymiarów geometrycznych, typu łożyska, rodzaju uzwojenia, liczby żłobków itp. Zakres modelowania dotyczy silników indukcyjnych małej...