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Wyniki wyszukiwania dla: MODEL EXTENSION AND SIMPLIFICATION
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Continuous-time active-RC filters: general model and its applications.
PublikacjaW pracy przedstawiono ogólny model filtru aktywnego RC opartego na wzmacniaczach odwracających fazę. Model analizowany jest przy użyciu równań macierzowych. Podano jawną formułę określającą funkcję przenoszenia filtru w ogólnym przypadku. Przedstawiono rozszerzenia modelu pozwalające uwzględniać nieidealności wzmacniaczy operacyjnych, w tym skończone wzmocnienie i pasmo przenoszenia oraz niezerową rezystancję wyjściową. Zastosowanie...
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Decisional DNA based intelligent knowledge model for flexible manufacturing system
PublikacjaModeling an effective mechanism for design and control strategies for the implementation of a flexible manufacturing system (FMS) has been a challenge. Consequently, to overcome this issue various techniques have applied in the past but most of these models are effective only for some specific situation or an element of FMS. In this study, the knowledge representation technique of Decisional DNA (DDNA) is applied to FMS to develop...
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A novel heterogeneous model of concrete for numerical modelling of ground penetrating radar
PublikacjaThe ground penetrating radar (GPR) method has increasingly been applied in the non-destructive testing of reinforced concrete structures. The most common approach to the modelling of radar waves is to consider concrete as a homogeneous material. This paper proposes a novel, heterogeneous, numerical model of concrete for exhaustive interpretation of GPR data. An algorithm for determining the substitute values of the material constants...
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Investigating Analytics Dashboards’ Support for the Value-based Healthcare Delivery Model
PublikacjaImproving the value of care is one of the essential aspects of Value-Based Healthcare (VBHC) model today. VBHC is a new HC delivery model which is centered on patient health outcomes and improvements. There is anecdotal evidence that the use of decision aid tools like dashboards can play a significant role in the successful implementation of VBHC models. However, there has been little or no systematic studies and reviews to establish...
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Numerical Model of the Aortic Valve Implanted Within Real Human Aorta
PublikacjaCardiovascular system diseases are the main cause of deaths in developed and developing countries. The main reasons are myocardial infarction, heart failure, stroke and valvular diseases. These are caused mainly by arteriosclerosis. The valvular diseases involve a significant burden for the health care system and their frequency is rising with the patient age. This work describes the tools and numerical models appropriate for modeling...
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Developing Methodology for Model Tests of Floating Platforms in Low -Depth Towing Tank
PublikacjaThe paper presents two different methods of physical modeling of semi-submersible platform mooring system for research in low depth towing tank. The tested model was made in the scale of 1:100 resembling the "Thunder Horse" platform moored in the Gulf of Mexico at a depth of 1,920 m. Its mooring system consisted of 16 semi-taut mooring lines (chain-wire-chain) spaced starshape and attached at the bottom to suction piles. The tests...
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Analysis of muscles behaviour : The computational model of muscle. -Part I
PublikacjaW artykule zaproponowano model obliczeniowy mięśnia szkieletowego, który potraktowano jako strukturę o złożonych i zróżnicowanych właściwościach mechanicznych. Szczegółowo opisano metodę identyfikacji tych właściwości. Ponadto określono sposób przeprowadzenia weryfikacji ilościowej i jakościowej zaproponowanego modelu. Za pomocą takiego obliczeniowego modelu mięśnia można łatwo określać siły w mięśniach, które należą do zespołu...
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Programmable dynamically changing RC model for evaluation of Dynamic EIS methods and instrumentation
PublikacjaThe paper concerns the RC equivalent circuit of electrochemical cell with the impedance changed during the experiment. The model was constructed using the digital potentiometers controlled by the microcontroller. This solution allows to control the model impedance by the software means. By creating adequate changes of the impedance spectrum as a time function, the different impedance measurement method can be tested to find out...
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Energetic model of hydraulic system of refuse collection vehicle based on simulation and experimental data
PublikacjaThis paper presents an energetic model of hydraulic system of a refuse collection vehicle. First, benefits resulting from implementation of an energetic model in the industry and operation of a Refuse Collection Vehicle are briefly explained. Then, components of the energy consumption in hydraulic circuits of compactor and lifting device are described and combined into a comprehensive model that can be evaluated using basic measurement...
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Vertical motions damping model test of a lifeboat lowered onto a flat sea surface
PublikacjaThe article presents the experiment’s results of the lifeboat model lowered with an initial speed and then released to fall onto a flat water surface. The purpose of the research is to determine the trajectory of the vertical boat motion and describe it with a mathematical model. This is closely related to determining the damping factor since the vertical motion is damped and the lifeboat gets balanced and stops moving after some...
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Continuum contact model for friction between graphene sheets that accounts for surface anisotropy and curvature
PublikacjaUnderstanding the interaction mechanics between graphene layers and co-axial carbon nanotubes (CNTs) is essential for modeling graphene and CNT-based nanoelectromechanical systems. This work proposes a new continuum contact model to study interlayer interactions between curved graphene sheets. The continuum model is calibrated and validated using molecular dynamics (MD) simulations. These are carried out employing the reactive...
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Stałoprądowy model tranzystora MOS z kanałem dłuzszym niż 10 nm
PublikacjaW artykule zaprezentowano spójny fizycznie, stałoprądowy jednosekcyjny model tranzystora MOS i wyniki jego eksperymentalnej weryfikacji dla szerokiego spektrum długości kanałów badanych tranzystorów - od kanałów długich aż do 10-nanometrowych. Przedstawiono założenia modelu fizycznego w przestrzeni 2-D i jego transformację do modelu quasi-dwuwymiarowego. Model spełnia warunek symetrii Gummel'a.
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Model oceny sytuacji ekonomiczno-finansowej przedsiębiorstw w gospodarce rynkowej
PublikacjaArtykuł jest polemiką z artykułem Sławomira Nahotko. Ma on charakter informacyjny dla osób zainteresowanych tematyką oceny sytuacji ekonomiczno-finansowej polskich przedsiębiorstw.Autor przedstawił w nim swój model sztucznych sieci neuronowych prognozowania zagrożenia upadłością firm.
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Simplified numerical model for global stability of corrugated silos with vertical stiffeners
PublikacjaArtykuł omawia wyniki stateczności globalnej silosów z blachy falistej z pionowymi usztywnieniami. Zaproponowano uproszczony model numeryczny metody elementów skończonych do określenia stateczności. Wyniki numeryczne były bardziej dokładnie niż metody zaproponowane w Eurokodzie.
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The influence of the thickness, recombination and space charge on the loss of photocurrent in organic semiconductors: an analytical model
PublikacjaWe propose an analytical model of the photocurrent efficiency dependence on the light intensity in organic semiconductors. The influence of the thickness of sample, space charge effects and recombination of charge on the loss of photocurrent has been considered. We demonstrate that the presented model is the enhancement of an analytical model reported recently by Rappaport et al (2005 J. Appl. Phys. 98 033714). The method to identify...
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An Empirical System Loss Model for Body Area Networks in a Passenger Ferry Environment
PublikacjaThis paper presents a general empirical system loss model for estimating propagation loss in Body Area Networks in off-body communications at 2.45 GHz in a passenger ferry environment. The model is based on measurements, which were carried out in dynamic scenarios in the discotheque passenger ferry environment. The model consists of three components: mean system loss, attenuation resulting from the variable antenna position on...
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Low-fidelity model considerations for simulation-based optimisation of miniaturised wideband antennas
PublikacjaHere, variable-fidelity electromagnetic (EM)-based design optimisation of miniaturised antennas is discussed. The authors focus on an appropriate selection of discretisation density of the low-fidelity EM model, which results in good performance of the optimisation algorithm in terms of its computational complexity and reliability. Trust-region gradient search with low-fidelity model corrected by means of non-linear frequency scaling...
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An Empirical System Loss Model for Body Area Networks in a Passenger Ferry Environment
PublikacjaThis paper presents a general empirical system loss model for estimating propagation loss in Body Area Networks in off-body communications at 2.45 GHz in a passenger ferry environment. The model is based on measurements, which were carried out in dynamic scenarios in the discotheque passenger ferry environment. The model consists of three components: mean system loss, attenuation resulting from the variable antenna position on...
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Model czynnikowy drugiego stopnia jakości informacji rynkowych
PublikacjaCelem pracy jest przedstawienie modelu pomiarowego jakości informacji rynkowych jako modelu czynnikowego drugiego rzędu. Do otrzymania tego modelu użyto konfirmacyjnej analizy czynnikowej. Uzasadnienie utworzenia modelu drugiego stopnia stanowiło wysokie skorelowanie czterech, pierwotnie założonych, czynników w modelu pomiarowym pierwszego rzędu oraz przesłanki merytoryczne. Rozpatrywane czynniki pierwszego rzędu to rzetelność,...
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Analytical Steady-State Model of the Pipeline Flow Process
PublikacjaThe paper addresses the issue of modeling the flow process in transmission pipelines. A base model used for numerical simulation is introduced. Under certain assumptions concerning steady state analysis, the differential equations describing the process are solved analytically for two cases: zero and nonzero inclination angle α. These equations describe a constant flow rate and a corresponding distribution of the pressure along...
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A new approach to determination of the two-mass model parameters of railway current collector
PublikacjaThe paper presents two mathematical models of railway current collectors both with two degrees of freedom. The first one, hereinafter Pantograph Articulated Model (PAM), has one degree of freedom in rotational motion and the second degree of freedom in translational motion. The second model, called henceforth as Pantograph Reference Model (PRM), has both degrees of freedom in translational motion. Differential equations of the...
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Modelling tunnelling-induced deformation in stiff soils with a hyperelastic–plastic anisotropic model
PublikacjaIn this paper, the tunnelling-induced deformation in anisotropic stiff soils is analysed using FE modelling. The influence of material description is investigated rather than an advanced simulation of the tunnelling method. A new hyperelastic– plastic model is proposed to describe the anisotropic mechanical behaviour of stiff highly overconsolidated soil. This model can reproduce the superposition of variable stress-induced anisotropy...
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A new approach to determination of the two-mass model parameters of railway current collector
PublikacjaThe paper presents two mathematical models of railway current collectors both with two degrees of freedom. The first one, hereinafter Pantograph Articulated Model (PAM), has one degree of freedom in rotational motion and the second degree of freedom in translational motion. The second model, called henceforth as Pantograph Reference Model (PRM), has both degrees of freedom in translational motion. Differential equations of the...
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Melanoma skin cancer detection using mask-RCNN with modified GRU model
PublikacjaIntroduction: Melanoma Skin Cancer (MSC) is a type of cancer in the human body; therefore, early disease diagnosis is essential for reducing the mortality rate. However, dermoscopic image analysis poses challenges due to factors such as color illumination, light reflections, and the varying sizes and shapes of lesions. To overcome these challenges, an automated framework is proposed in this manuscript. Methods: Initially, dermoscopic...
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Uniform Model Interface for Assurance Case Integration with System Models
PublikacjaAssurance cases are developed and maintained in parallel with corresponding system models and therefore need to reference each other. Managing the correctness and consistency of interrelated safety argument and system models is essential for system dependability and is a nontrivial task. The model interface presented in this paper enables a uniform process of establishing and managing assurance case references to various types...
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Flood Routing by the Non-Linear Muskingum Model: Conservation of Mass and Momentum
PublikacjaIn this paper, the conservative properties of the Muskingum equation, commonly applied to solve river flood routing, are analysed. The aim of this analysis is to explain the causes ofthe mass balance error, which is observed in the numerical solutions of its non-linear form. The linear Muskingum model has been considered as a semi-discrete form of the kinematic wave equation and therefore it was possible to derive its two non-linear...
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Minimal parameter implicit solvent model for ab initioelectronic-structure calculations
PublikacjaAbstract - We present an implicit solvent model for ab initio electronic-structure calculations which is fully self-consistent and is based on direct solution of the nonhomogeneous Poisson equation. The solute cavity is naturally defined in terms of an isosurface of the electronic density according to the formula of Fattebert and Gygi (J. Comput. Chem., 23 (2002) 662). While this model depends on only two parameters, we demonstrate...
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Simulation model for assessment of IMS-based NGN call processing performance
PublikacjaIn current telecommunications it is assumed that demands of information society for quickly delivered services will be satisfied by Next Generation Network (NGN) architecture, which includes IP Multimedia Subsystem (IMS) elements. To guarantee Quality of Service (QoS), proper design and dimensioning of NGN is absolutely necessary, for which appropriate models have to be proposed. As NGN architecture is very complicated, the most...
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Orthotropic membrane as a mechanical model of surgical implant in abdominal hernia repair
PublikacjaEven though the incisional hernia repair surgery is a well known procedure, mechanical properties of the tissue-implant system are unknown so the implantation of the repairing mesh is quite intuitive and, recurrences of the illness still take place. The main objective of the study is to define an operated hernia model that can be used for surgery planning and the assessment of the repair persistence. The load applied to the structure...
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Proposal of a System Loss Model for Body Area Network in Passenger Ferry Environment
PublikacjaIn the paper, proposal of an empirical off-body system loss model for Body Area Networks working in a passenger ferry environment at 2.45 GHz has been presented. The measurements were carried out for dynamic scenarios in the discotheque passenger ferry environment. The general model formula consists of three components: mean system loss, attenuation resulting from the variable antenna position on the human body, and attenuation...
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Discrete element method modelling of elastic wave propagation in a meso-scale model of concrete
PublikacjaThis paper deals with the accurate modelling of ultrasonic wave propagation in concrete at the mesoscopic level. This was achieved through the development of a discrete element method (DEM) model capable of simulating elastic wave signals comparable to those measured experimentally. The main objective of the work was to propose a novel methodology for constructing a meso-scale model of concrete dedicated to the analysis of elastic...
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Analytical model of torsional vibrations of typical sawing machine main drive system
PublikacjaPrzedstawiono model fizyczny i matematyczny drgań skrętnych napędu głównego typowej pilarki tarczowej. Model tworzą elementy sztywne SES połączone między sobą za pośrednictwem elementów sprężysto - tłumiących EST w układzie szeregowym. W modelu matematycznym uwzględniono: właściwości dynamiczne silnika napędowego, wymiary piły tarczowej, cechy materiału obrabianego (wymiary, rodzaj drewna, wilgotność drewna) oraz właściwości dynamiczne...
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Takagi-Sugeno Fuzzy Model of Dissolved Oxygen Concentration Dynamics in a Bioreactor at WWTP
PublikacjaThe importance of dissolved oxygen concentration controlinaerationtanksofabioreactoratflow-throughwastewater treatment plant (WWTP) can easily be justified by technological requirements as well as simple economics. Firstly, appropriate levels of dissolved oxygen concentration are essential for the vitality of microorganisms that comprise the bioreactor. Secondly, the costs of dissolved oxygen concentration control related to the...
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An Intergrated Model of Motion, Steering, Positioning and Stabilization of an Unmanned Autonomous Maritime Vehicle
PublikacjaIn the paper the aim of an interdisciplinary research is presented. The research method is introduced. An object the unmanned autonomous maritime vehicle is briefly described. The key research problem concerns a combined model of the vehicle motion including the loads of lift and hydrodynamic nature. The model takes into account the gravity and displacement forces, resistance and thrust forces, lift and other hydrodynamic forces....
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Model zużycia głównych podzespołów zespołu korbowo-tłokowego i rozrządu
PublikacjaW referacie na podstawie uszkodzeń zespołu korbowo-tłokowego i rozrządu silników Sulzer RD pobranych z syntetycznych danych o niezawodności wyposażenia wybranych statków PLO i PŻM zbudowany został model zużycia głównych podzespołów zespołu korbowo-tłokowego i rozrządu.
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The role and concept of sub-models in the smart fuzzy model of the internet mortgage market
PublikacjaThe paper introduces some challenges of the fast growing mortgage market in Poland. One of these challenges is the need for a model development that could be used for various predictions related to this market. At the current stage of the model evelopment process our main goal is to propose and introduce sub-models the role of which would be to describe three different economic environments: stable, fast growing, and recession....
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Comparison of Compact Reduced Basis Method with Different Model Order Reduction Techniques
PublikacjaDifferent strategies suitable to compare the performance of different model order reduction techniques for fast frequency sweep in finite element analysis in Electromagnetics are proposed and studied in this work. A Frobenius norm error measure is used to describe how good job a reduced-order model is doing with respect to the true system response. In addition, the transfer function correct behavior is monitored by studying the...
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Simulation model for evaluation of QoS routing algorithm in large packet networks
PublikacjaThe variety of traffic transferred via current telecommunication networks includes also voice, which should meet quality requirements. One of mechanisms, which can support QoS in current packet networks, is routing. There exist many routing proposals which should introduce the QoS into the network but practically they don't. Following paper presents the realization of simulation model for evaluation of a new routing algorithm DUMBRA...
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Model of the reciprocating engine using iterative procedures of the transient torque calculation
PublikacjaPrzedstawiony w pracy model silnika spalinowego uzależnia wartość dynamicznego momentu od sygnału sterowania po skokowej zmianie nastawy oraz od historii dynamicznej silnika i czasu jaki upłynął od tej zmiany. Przedstawione wyniki badań potwierdzają zasadność takiego opisu modelowanego zjawiska. Można również zauważyć, że po pewnym czasie od chwili rozpoczęcia procesu rozpędzania przebieg momentu dynamicznego będzie przebiegał...
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Efficient model order reduction for FEM analysis of waveguide structures and resonators
PublikacjaAn efficient model order reduction method for three-dimensional Finite Element Method (FEM) analysis of waveguide structures is proposed. The method is based on the Efficient Modal Order Reduction (ENOR) algorithm for creating macro-elements in cascaded subdomains. The resulting macro-elements are represented by very compact submatrices, leading to significant reduction of the overall number of unknowns. The efficiency of the model...
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A mechanistic model for fate and removal of estrogens in biological nutrient removal activated sludge systems
PublikacjaTwo estrogen fate and transformation models were integrated with a comprehensive activated sludge model (ASM) to predict estrogen removal based on biomass and solids production. Model predictions were evaluated against published full-scale plant data as well as results from a laboratory-scale sequencing batch reactor (SBR) fed synthetic wastewater. The estrogen fate model relating the rate of total estrogen degradation to soluble...
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Stable indirect adaptive control based on discrete-time T-S fuzzy model
PublikacjaThis paper presents an indirect adaptive fuzzy control scheme for uncertain nonlinear asymptotically stable plants.A discrete-time T-S fuzzy input-output model is employed to approximate the unknown plant dynamics. The T-S fuzzy model is fed with its own states, which are indeed its past outputs, rather than the measurements from the plants. Entirely based on this model, a feedback linearization control law is designed by using...
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Stable indirect adaptive control based on discrete-time T-S fuzzy model
PublikacjaThis paper presents an indirect adaptive fuzzy control scheme for uncertain nonlinear asymptotically stable plants.A discrete-time T-S fuzzy input-output model is employed to approximate the unknown plant dynamics. The T-S fuzzy model is fed with its own states, which are indeed its past outputs, rather than the measurements from the plants. Entirely based on this model, a feedback linearization control law is designed by using...
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A MULTI-MASS DISCRETE MODEL OF TRIBOMETER FOR THE RESEARCH ON DYNAMIC FRICTION CHARACTERISTICS = Wielomasowy dyskretny model tribometru do symulacyjnych badań dynamicznych charakterystyk tarcia
PublikacjaW artykule przedstawiono metodykę opracowaną w celu redukcji modelu fizycznego tribometru z ciągłym rozkładem masy (bezwładności), sztywności podparcia oraz tłumienia do modelu dyskretnego. W modelu dyskretnym zastosowano zastępcze masy skupione i elementy sprężysto - tłumiące, których właściwości są dobrane w taki sposób, że charakterystyka drgań własnych tego modelu odpowiada charakterystyce rzeczywistego układu fizycznego. Dzięki...
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The choice of parameters of induction motor model using a genetic algorithm.
PublikacjaRozważano problem doboru parametrów modeli matematycznych dużych 3 -fazowych silników indukcyjnych. Modele o prawidłowo dobranych parametrach mogą być pomocne podczas procedur projektowych. Podane silniki mogą być używane jako napędy sterów strumieniowych statków. Symulacje w środowisku Matlab, uwzględniają modele statyczne silników. Parametry silników dobierane są za pomocą przybornika Genetic Algorithm Toolbox. Skuteczność metody...
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Softly Switched Robustly Feasible Model Predictive Control for Nonlinear Network Systems
PublikacjaIt is common that an efficient constrained plant operation under full range of disturbance inputs require meeting different sets of control objectives. This calls for application of model predictive controllers each of them being best fit into specific operating conditions. It further requires that not only designing robustly feasible model predictive controllers is needed to satisfy the real plant state/output constraints, but...
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Reliable Greedy Multipoint Model-Order Reduction Techniques for Finite-Element Analysis
PublikacjaA new greedy multipoint model-order reduction algorithm for fast frequency-domain finite-element method simulations of electromagnetic problems is proposed. The location of the expansion points and the size of the projection basis are determined based on a rigorous error estimator. Compared to previous multipoint methods, the quality of the error estimator is significantly improved by ensuring the orthogonality of the projection...
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Laboratory Determination of Burger's Model Parameters for Visco-elastic Analysis of Road Pavement Materials
PublikacjaBurger's Model is one of those models that describes performance of asphalt mixtures. Its parameters can be used in road construction analysis based on visco-elastic properties in wide variety of temperatures using dedicated programs (e.g. Veroad) or in Finite Element Method (FEM). Parameters of Burger's Model can be used for example in prediction of low temperature cracking in low winter temperatures or permanent deformation...
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A material model of asphalt mixtures based on Monte Carlo simulations
PublikacjaThe 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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Model-based testing for execution algorithms in the simulation of cyber-physical systems
PublikacjaThe understanding of simulation semantics of a hybrid system is a challenge for computational engineers as it requires expertise in computer science, engineering, numerical methods, and mathematics at once. The testing methods for the execution of a simulation are being researched but not yet applied on the industrial level. Consequently, the semantics of the simulation becomes a critical artifact in the system development process....