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wszystkich: 351
Wyniki wyszukiwania dla: computer simulation
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Computer simulation of detonation of shaped charge in sea water
PublikacjaArtykuł zawiera opis systemu przeciwnimowego Głuptak, koncentrując się na opisie działania ładunku kumulacyjnego do niszczenia min morskich. Opisano sposób formowania wiązki plazmy uderzającej w obudowę miny po zdetonowaniu opisywanego ładunku kształtowego. Zaprezentowano obraz symulacyjny i zdjęcia poklatkowe penetracji plazmy w obiekcie niszczonym.
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Non-linear electrical properties of myocardium in computer simulation
PublikacjaPomiar impedancji elektrycznej jest obiecującą metodą monitorowania stanu mięśnia sercowego, szczególnie podczas niedokrwienia. Typową metodą pomiaru jest rejestrowanie odpowiedzi-napięcia na pobudzenie prądowe. Odpowiedź jest często aproksymowana jako liniowa względem pobudzenia. Artykuł jest poświęcony oszacowaniu rzędu wielkości nieliniowych komponentów w odpowiedzi.
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Mathematical Modelling and Computer Simulation of Activated Sludge Systems
PublikacjaPrzegląd systemów osadu czynnego. Rozwój modeli procesu osadu czynnego. Podstawowe definicje z zakresu modelowania matematycznego i symulacji komputerowej. Proces budowy modelu (model biokinetyczny, hydrodynamiczny, transferu tlenu, temperatury). Modelowanie procesów biochemicznych zachodzących w systemach osadu czynnego. Organizacja badań symulacyjnych. Praktyczne zastosowania modeli osadu czynnego.
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Computer simulation of induction heating system with series inverter
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Computer simulation of induction hardening of moving flat charge
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Modelling the set of earthworks machinery with the use of computer simulation
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Dynamics of Opposing Polymer Brushes: A Computer Simulation Study
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Computer Simulation in Predicting Biochemical Processes and Energy Balance at WWTPs
PublikacjaNowadays, the use of mathematical models and computer simulation allow analysis of many different technological solutions as well as testing various scenarios in a short time and at low financial budget in order to simulate the scenario under typical conditions for the real system and help to find the best solution in design or operation process. The aim of the study was to evaluate different concepts of biochemical processes and...
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Mathematical modelling and computer simulation of activated sludge systems.Second edition
PublikacjaMathematical Modelling and Computer Simulation of Activated Sludge Systems – Second Edition, provides, from the process engineering perspective, a comprehensive and up-to-date overview regarding various aspects of the mechanistic (“white box”) modelling and simulation of advanced activated sludge systems performing biological nutrient removal. In the new edition of the book, a special focus is given to nitrogen removal and an overview...
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Geo-engineering computer simulation seems attractive but is it the real world?
PublikacjaCorrect formulation of the differential equation system for equilibriom conditions of subsoil, especially in terms of controlled numerical calculation, is discussed. The problem of solution stability is also considered. The solution of problems, which are ill-posed, have no practical value in the majority of cases and is this way the engineering prognosis can lead to real disaster. The object of this paper is quite relevant if...
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Research of Emergency Modes of Wind Power Plants Using Computer Simulation
PublikacjaThe aim of this study is to investigate changes in the wind power plant energy production parameters under the conditions of sudden wind changes and voltage drop. To achieve these goals, a simulation of operation of wind power plants was performed. Twelve wind turbines with variable rotational speed equipped with a Fuhrländer FL 2500/104 asynchronous double-fed induction generator (DFIG) were used, each with an installed capacity...
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Experiences with computer simulation at two large wastewater treatment plants in northern Poland
PublikacjaPrzedstawiono wyniki symulacji pracy wielofazowych komór osadu czynnego w stanie ustalonym, uzyskanych za pomocą programu GPS-X. Jako dane wejściowe wykorzystano wyniki oznaczeń konwencjonalnych parametrów wykonywanych w trakcie eksploatacji oczyszczalni ścieków "Dębogórze" w Gdyni i "Wschód" w Gdańsku. Jako parametry kontrolne, służące do porównania wyników pomiarów i obliczeń, wykorzystano stężenie ChZT, azotu amonowego, azotanów...
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Computer simulation of current voltage response of elektrocatalytic sensor.Optoelectronic and Electronic Sensors V.
PublikacjaW pracy przedstawiono wyniki symulacji komputerowej działania czujnika elektrokatalitycznego. Do badań wykorzystano program D. Gossera opierający się na metodzie różnic skończonych.
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Surgical implant used in ventral hernia repair subjected to physiological pressure - computer simulation
PublikacjaW streszczeniu przedstawiono matemayczny model implantu wszczepionego pacjentowi podczas laparoskopowej naprawy przepukliny brzusznej. Wykonano go z użyciem metody elementów skończonych. Przyjęto ortotropowy model materiałowy implantu.
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Influence of addition of carbon nanotubes on rheological properties of selected liquid lubricants - a computer simulation study
PublikacjaThis work is motivated by the improvement of anti-friction properties of lubricants by addition of CNTs proved experimentally in literature. In particular, a methodology is developed to compute the shear viscosity of liquid lubricants (Propylene Glycol) based on Molecular Dynamics simulation. Non-Equilibrium molecular dynamics (NEMD) approach is used with a reactive force field ReaxFF implemented in LAMMPS. The simulations are...
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An Attempt to Develop a Model Selection Algorithm of Computer Simulation during the Design Process of Mechanical Response of Any Mechanical Body
PublikacjaIn the literature, there are algorithms associated with the design of simulations of technological processes, in which the material model has always been defined previously. However, in none of the studies of computer simulation modelling of technological processes known to the authors of this article, is there a detailed description of how the algorithm, or the selection of plastic model used, is subject to this process. This...
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An attempt to develop a model selection algorithm of computer simulation during the design process of mechanical response of any mechanical body
Publikacjan the literature, there are algorithms associated with the design of simulations of technological processes, in which the material model has always been defined previously. However, in none of the studies of computer simulation modelling of technological processes known to the authors of this article, is there a detailed description of how the algorithm, or the selection of plastic model used, is subject to this process. This article...
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Computer simulation of vibration surveillance of discretely idealised mechanical systems. Part II: Tool-workpiece vibration in a non-stationary model of the cutting process
PublikacjaPrzedmiotem rozważań jest problem nadzorowania drgań narzędzie-przedmiot obrabiany w procesie skrawania. Dokonano analizy obiektu badań oraz dynamiki skrawania. Utworzono niestacjonarny model obliczeniowy. Przedstawiono różne podejścia oraz przykłady symulacji komputerowych nadzorowania drgań z wykorzystaniem modelu niestacjonarnego. Bazowały one na sterowaniu optymalnym oraz sterowaniu skokową zmiana prędkości obrotowej wrzeciona....
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Computer simulation of vibration surveillance of discretely idealised mechanical systems. Part I: Optimal control at the energy performance index for open non-stationary systems
PublikacjaPraca dotyczy sposobów nadzorowania drgań mechanicznych z wykorzystanie elementów teorii sterowania, optymalizacji dynamicznej, nowoczesnych metod symulacji komputerowej oraz technik pomiarowych. Do modelowania niestacjonarnego układu sterowanego zastosowano mieszaną metodą sztywnych i odkształcalnych elementów skończonych. Opracowano metodę nadzorowania drgań w dziedzinie czasu, z wykorzystaniem sterowania optymalnego przy energetycznym...
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ACM Transactions on Modeling and Computer Simulation
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Computer simulations of hearing aid acoustical system performance
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Polymerization and Structure of Opposing Polymer Brushes Studied by Computer Simulations
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Star Polymers vs. Dendrimers: Studies of the Synthesis Based on Computer Simulations
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A new approach to modeling of selected human respiratory system diseases, directed to computer simulations
PublikacjaThis paper presents a new versatile approach to model severe human respiratory diseases via computer simulation. The proposed approach enables one to predict the time histories of various diseases via information accessible in medical publications. This knowledge is useful to bioengineers involved in the design and construction of medical devices that are employed for monitoring of respiratory condition. The approach provides the...
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Using On-line Measurement by Electronic Nose and Computer Simulations for Real-time Control at WWTP
PublikacjaContinuous investigation of wastewater quality can be carried out by a device called an e-nose. One important feature of the proposed real-time control system for WWTP is that using on-line measurements by e-nose together (Figure 1) with technological sets picked on this basis by means of computer models, it is possible to change treatment process parameters, depending on the current quality of wastewater. It can be used for the...
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Use of Innovative and Advanced Computer Simulations of Chemical Speciation of Heavy Metals in Soils and Other Environmental Samples
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Comparison of the exponential thermal transient parameterization methods with the SMTP method in the unipedicled DIEP flap computer modelling and simulation
PublikacjaThe aim of this paper is to compare the spatial contrast of the image descriptors obtained via three different thermal transient parameterization methods in Active Dynamic Thermography. The thermal constants and amplitude values of the one- and two- exponential parametrization are compared to the Simplified Magnitude-Temporal Parametrization method (SMTP). The comparison is performed using the data obtained by simulating the cold...
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Innovations in Wastewater Treatment: Harnessing Mathematical Modeling and Computer Simulations with Cutting-Edge Technologies and Advanced Control Systems
PublikacjaThe wastewater treatment landscape in Central Europe, particularly in Poland, has undergone a profound transformation due to European Union (EU) integration. Fueled by EU funding and rapid technological advancements, wastewater treatment plants (WWTPs) have adopted cutting-edge control methods to adhere to EU Water Framework Directive mandates. WWTPs contend with complexities such as variable flow rates, temperature fluctuations,...
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Short-range order structure and free volume distribution in liquid bismuth: X-ray diffraction and computer simulations studies
PublikacjaThe structure of liquid bismuth was studied by X-ray diffraction and computer simulation methods. The contraction of the atomic structure within the first coordination sphere in the temperature interval of 575- 1225 K is reported. The temperature dependencies of the coordination numbers and of the free volume are analysed. On the basis of the temperature dependencies of the free volume, the temperature dependencies of viscosity...
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Trees as a Shading System for Streets on the East–West Axis: Computer Simulations for the Selected Geometrical Proportions of Building Developments in Humid Continental Climate
PublikacjaThe study is aimed at investigating the possibilities for solar protection provided to the street canyon located on the E–W axis and with the following profiles: shallow (height/width (H/W) = 0.2, 0.6, and 1) and deep (H/W = 2) by two rows of trees located at a distance of 3 m away from southern and northern façades. The research was based on numerical simulation analyses conducted in the Rhinoceros® program, with the application...
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Summer Computer Simulation Conference
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Symposium Model Analysis and Simulation of Computer and Telecommunications Systems
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Mathematical Models and Computer Simulations
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Three dimensional fluid equations from distribution function with discontinuity in velocity space
PublikacjaUkład równań typu hydrodynamicznego dla rozwarstwionego gazu w polu grawitacyjnym jest wyprowadzony z równania BKG przy użyciu metody kawałków ciągłej funkcji dystrybucji. Otrzymany układ równań uogólnia układ Naviera-Stokesa dla dowolnych liczb Knudsena.
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Software Agents for Computer Network Security
PublikacjaThe chapter presents applications of multi-agent technology for design and implementation of agent-based systems intended to cooperatively solve several critical tasks in the area of computer network security. These systems are Agent-based Generator of Computer Attacks (AGCA), Multi-agent Intrusion Detection and Protection System (MIDPS), Agent-based Environment for Simulation of DDoS Attacks and Defense (AESAD) and Mobile Agent...
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Computer support of analysis optical spectra measurements
PublikacjaVerification of measurement errors has a big impact on assessment of accuracy of conducted measurements and obtained results. In many cases computer simulation results are compared with measurement results in order to evaluate measurement errors. The purpose of our research was to check the accuracy of measurements made with Fabry-Perot interferometer working in the transmission mode. In measurement setup, a 1310 nm superluminescent...
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Computer Support of Analysis of Optical Spectra Measurements
PublikacjaThe verification of measurement errors has a big impact on the assessment of the accuracy of conducted measurements and obtained results. In many cases, computer simulation results are compared with measurement results in order to evaluate measurement errors. The purpose of our research was to check the accuracy of measurements made with a Fabry–Perot interferometer working in the transmission mode. In the measurement setup, a...
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Tracing of dynamic objects in distributed interactive simulation systems
PublikacjaDistributed interactive simulation systems require integration of several areas of computer science and applied mathematics to enable each individual simulation object to visualize effectively dynamic states of other objects. Objects are unpredictable,i.e., controlled by their local operators, and are remote, i.e., must rely on some transmission media to visualize dynamic scene from their local perspectives. The paper...
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Supporting development of the smart ship technology by CFD simulation of ship behavior in close to real operational conditions
PublikacjaThe shipping industry is at the milestone of technological development – autonomous ships. Involving smart technologies accelerates development of green and safe shipping. Also IMO regulations, especially EEDI en-hanced application of new technologies. Meeting economic and ecological requirements future ships need to be designed with respect to increased reliability and operational performance. Design process of ships may be improved...
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Possible uses of crisis situation aiding system in virtual world simulation
PublikacjaMany of the real world crisis situations like spreading fire, hostile units attack, flood, and etc. are commonly used in computer games where a simulation of extensive virtual world is crucial. This paper presents some ideas for possible uses of existing crisis situation aiding system in such environments. Moreover it shows how this kind of system can be taught during subsequent games with a large number of players.
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Simulation of fluid structure interaction in a novel design of high pressure axial piston hydraulic pump
PublikacjaA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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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....
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Computer Supported Analysis of the Human Body Surface Area
PublikacjaRecent scientific studies show the growing importance of the coefficients: BSA and TBSA, as an alternative to the widely used BMI. The relevant indicators are widely used in medicine, including such areas as: the treatment of burns, chemotherapy, dermatology and toxicology; as benchmarks when calculating doses of drugs and fluids. The particular problems concerning this subject are: the change of the reference parameter value which...
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Possible uses of crisis situation aiding system in virtual world simulation
PublikacjaMany of the real world crisis situations like spreading fire, hostile units attack, flood, and etc. are commonly used in computer games where a simulation of extensive virtual world is crucial. This paper presents some ideas for possible uses of existing crisis situation aiding system in such environments. Moreover, it shows how this kind of system can be taught during subsequent games with a large number of players. As an example...
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Molecular dynamics and verisimilitude - to what extent can one trust a computational simulation?
PublikacjaFor the last several tens of years, computer simulations have become of undeniable importance. Molecular Dynamics (MD) simulation techniques are used to examine the phenomena which occur at the level that cannot be observed directly. Thus, they can be successfully exploited in many different scientific fields such as: materials science, applied mathematics and theoretical physics, biochemistry, biophysics or drug design. Despite...
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Comparative analysis of coaxial magnetocumulative generators
PublikacjaThis paper presents the results of a computer simulation of coaxial magnetocumulative current generators (MCGs). The simulation tests were carried out for different values of the internal diameter, length and speed of the deformation of the MGP element.
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Mathematical Models in Design Process of Ship Bow Thrusters
PublikacjaThe paper describes an application of simulation models for computer-aided design of ship bow thrusters. Generation of simulation models of ship bow thruster requires development and verifying of mathematical models of system component elements. Using the results of simulation the expert system is able to determine, that the rules of classification societies are met. Design procedures and mathematical models are part of an expert...
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Mathematical Models in Design Process of Ship Bow Thrusters
PublikacjaThe presentation is about an application of simulation models for computer-aided design of ship bow thrusters. Generation of simulation models of ship bow thruster requires development and verifying of mathematical models of system component elements. Using the results of simulation the expert system is able to determine, that the rules of classification societies are met. Design procedures and mathematical models are part of an...
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PROBLEMS OF THE STARTING AND OPERATING OF HYDRAULIC COMPONENTS AND SYSTEMS IN LOW AMBIENT TEMPERATURE (PART IV) MODELLING THE HEATING PROCESS AND DETERMINING THE SERVICEABILITY OF HYDRAULIC COMPONENTS DURING THE STARTING-UP IN LOW AMBIENT TEMPERATURE
PublikacjaDesigners of hydraulically driven machines and devices are obliged to ensure during design process their high service life with taking into account their operational conditions. Some of the machines may be started in low ambient temperature and even in thermal shock conditions (due to delivering hot working medium to cold components). In order to put such devices into operation appropriate investigations, including experimental...
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Computational simulation of motion of a rescue module during its launching from ship at rough sea
PublikacjaThis paper is a continuation of the work titled : “A comp utational model for simulation of motion of rescue module during its launching from stern ramp of a ship at rough sea”. It presents results of computer simulations of motion of a rescue module with embarked persons during its launching on rollers along stern ramp of a ship at rough sea. The simulations were conducted for a selected ship fitted with a launching ramp , for...
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AN ATTEMPT AT IDENTIFYING THE INFLUENCE OF TEST HEAD ASSEMBLY STIFFNESS ON THE RESULTS OF A TRIBOLOGICAL EXPERIMENT CONDUCTED UNDER MICRO-OSCILLATION CONDITIONS
PublikacjaThe outcome of experimental research on a group of dry bearing materials carried out under small oscillation conditi ons and using a test rig designed and made at Gdansk University of Technology inspired the decision to find out if the stiffness of test head elements in fluenced the generated results. Therefore, a computer model utilising finite elements was devised and used to simulate the workings of the test head. The mode l...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston pump
PublikacjaA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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An facile Fortran-95 algorithm to simulate complex instabilities in three-dimensional hyperbolic systems
Dane BadawczeIt is well know that the simulation of fractional systems is a difficult task from all points of view. In particular, the computer implementation of numerical algorithms to simulate fractional systems of partial differential equations in three dimensions is a hard task which has no been solved satisfactorily. Here, we provide a Fortran-95 code to solve...
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The flux compression generator load parameters selection
PublikacjaComputer simulation results of the flux compression generator (FCG) loaded with an inductor has been presented in this paper. Simulation research has been performed in order to select the parameters of FCG load coil properly. The influence of the load inductance and resistance on the current gain factor and the magnetic field energy accumulated in a load coil has been investigated.
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Semantics for an Interdisciplinary Computation
PublikacjaSemantics for an interdisciplinary computation is becoming increasingly difficult to capture while dealing with multi-domain problems. Expertise from Computer Science, Computer Engineering, Electrical Engineering, and other disciplines merges as engineering challenges in modern systems, such as, Cyber-Physical Systems, Smart Cities, and Bionic Systems must be tackled in a methodological manner. In this paper, a paradigm for formalization...
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The Multiplatform Environment for Simulation and Features Estimation of Mixed-Signal Devices
PublikacjaThe use of simulation laboratories is gaining popularity in thedomains of engineering programs. However, the experience in teaching showsthat the simulation itself is not very effective in didactic processes. Teachingprocesses in thefield of specialist subjects, designed for students of technicaluniversities, should be based on direct operations performed by the student onreal devices. At the same time, at the later stages of didactic...
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Agent-based social network as a simulation of a market behaviour
PublikacjaRecent years and the outbreak of world's economic crisis in 2008 proved the crucial importance of reliable analysis of market dynamics. However, werarely apply models of proper detail level (the global prosperity forecast of 2007 can be seen as a grim proof). The behaviour of individuals and companies is far from being ideal and rational. Many claims that the economic paradigm of rational expectations (coming from J. Muth and R....
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MAlSim - Mobile Agent Malware Simulator
PublikacjaOne of the problems related to the simulation of attacks against critical infrastructures is the lack of adequate tools for the simulation of malicious software (malware). Malware attacks are the most frequent in the Internet and they pose a serious threat against critical networked infrastructures. To address this issue we developed Mobile Agent Malware Simulator (MAISim). The framework uses the technology of mobile agents and...
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Hybrid stepless distribution transformer with four-quadrant AC/DC/AC converter at low voltage side - simulation tests
PublikacjaThe article presents the work of the stepless hybrid distribution transformer (HT), as an alternative to the so far applied Automatic Voltage Regulator (AVR) solutions, used to control the voltage in the power system in terms of the fundamental harmonic. The HT is a combination of a conventional distribution transformer and an AC/DC/AC converter connected in series with the transformers secondary winding. In the work the basic...
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Developments in manufacturing engineering and machining process planning
PublikacjaCurrent research conducted in the Department of Manufacturing Engineering and Automation is presented in the paper. This includes: abrasive cutting off, grinding with lapping kinematics, rapid prototyping and machining procrss planning. Experimental results and computer simulation are presented and analysed.
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Reinforcement Learning Algorithm and FDTD-based Simulation Applied to Schroeder Diffuser Design Optimization
PublikacjaThe aim of this paper is to propose a novel approach to the algorithmic design of Schroeder acoustic diffusers employing a deep learning optimization algorithm and a fitness function based on a computer simulation of the propagation of acoustic waves. The deep learning method employed for the research is a deep policy gradient algorithm. It is used as a tool for carrying out a sequential optimization process the goal of which is...
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Hybrid Expert System for Computer-Aided Design of Ship Thruster Subsystems
PublikacjaThe article presents an expert system supporting the design of ship's power subsystems, in particular the thruster subsystem. The proposed hybrid expert system uses the results of simulation tests as the additional source of knowledge. The results of system operation are collated in a report which can be used as part of ship design description. The work oriented on developing the expert system is the continuation of the research...
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Evolutionary Sets of Safe Ship Trajectories: simulation results
PublikacjaThe Evolutionary Sets of Safe Ship Trajectories is a method solving multi-ship encounter situations. For given positions and motion parameters the method finds a near optimal set of safe trajectories of all ships involved in an encounter. The paper briefly presents foundations of the method and focuses on simulation results for selected test cases based on the Baltic Basin. The computer simulations cover both open waters and restricted...
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Analysis of economical lighting of highways in the environment of SMOL language
PublikacjaThe paper puts forward and implements a method of designing and creating a modelling simulation environment for eztensive and complete analysis of economical lighting on highways. From a general design viewpoint, the proposed solution explores the concept of a network description language (SMOL), which has been designed to describe the necessary network functions, mechanisms, and devices; for the purpose of their computer simulation...
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Novel analysis methods of dynamic properties for vehicle pantographs
PublikacjaTransmission of electrical energy from a catenary system to traction units must be safe and reliable especially for high speed trains. Modern pantographs have to meet these requirements. Pantographs are subjected to several forces acting on their structural elements. These forces come from pantograph drive, inertia forces, aerodynamic effects, vibration of traction units etc. Modern approach to static and dynamic analysis should...
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Quadratic stochastic operators as a tool in modelling the dynamics of a distribution of a population trait
PublikacjaQuadratic stochastic operators can exhibit a wide variety of asymptotic behaviours and these have been introduced and studied recently. In the present work we discuss biological interpretations that can be attributed to them. We also propose a computer simulation method to illustrate the behaviour of iterates of quadratic stochastic operators.
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Modelling of Different Aeration Modes Influencing Processes in SBR Bioreactor
PublikacjaCurrently, computer modelling together with the simulation tools tailored for that purpose constitute a very important element in planning technological changes within wastewater treatment plant. From the point of view of the WWTP operator every modification should be introduced in order to improve the quality of treated sewage with the lowest financial outlays. These requirements can be met by using computer programmes to effectuate...
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Simulation analysis of a production process with selected six sigma ratios
PublikacjaComputer technologies allow more and more to model as well as to perform simulation experiments of various processes. The simulation analysis provides a better understanding of the interdependencies between various stages of production processes.The results of simulation studies were presented, the aim of them was to show the opportunities of the analysis of the process according to the scenarios and variants developed in connection...
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Dynamic Positioning System with Vectorial Backstepping Controller
PublikacjaThe problem of synthesis a dynamic positioning system for low frequency model of surface vessel was considered in this paper. The recursive vectorial backstepping control design was used to keep a fixed position and heading in presence of wave disturbances. The passive observer was introduced to smooth the measurements and to estimate the velocities needed for the control algorithm. Some parameters of observer were optimized off-line...
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An algorithm to generate high dense packing of particles with various shapes
PublikacjaDiscrete Element Method (DEM) is one of available numerical methods to compute movement of particles in large scale simulations. The method has been frequently applied to simulate the cases of grain or bulk material as the major research issue. The paper describes a new method of generating high dense packing with mixed material of two different shape used in DEM simulation. The initial packing is an important parameter to control,...
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The experimental evaluation and modeling of SBR removing nutrients under varied aeration conditions
PublikacjaSequencing batch reactors (SBR) are mainly characterized by sequential process phases of fill, react, settle, decant and idle periods that allow considerable flexibility in the design and operation in different conditions. This flexibility and the unique features of SBRs used to wastewater treatment by activated sludge systems operated in laboratory scale, allow not only conducting experiments for the standard conditions but also...
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Tuning of the plasmon resonance location in Au nanostructures coated with a ultrathin film of Al2O3 – Optical measurements and FDTD simulations
PublikacjaThe Au nanostructures have been coated with an ultra-thin films of amorphous aluminium oxide. Optical absorption spectra show the influence of the thickness of Al2O3 on plasmon resonance wavelength. The observed red-shift of the resonance location with the increase of the thickness of the Al2O3 film, can be explained by the change in the dielectric function of this film. It allows control of the optical spectra of the coated particles....
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New Generation of Water lubricated Foil bearing - Numerical Models and Experimental Verification
PublikacjaIn the paper a new idea of foil water lubricated bearing and methodology of hydrodynamic characteristics calculations is presented. To assesses the theoretical characteristics of these bearings two different computer models were built. First is structural model coupled with fluid model. It takes into account: fluid flow in the deformed fluid gap, specific design of bearing support and friction in bearing support. The second is...
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A New Quaternion Encryption Scheme for Image Transmission
PublikacjaQuaternions are hypercomplex number of rank 4. They are often applied to mechanics in three-dimensional space and considered as one of the best ways to represent rotations. In this paper a new encryption scheme, based on the rotation of data vector in three-dimensional space around another quaternion (key) is proposed. A computer-based simulation was created to analyze the potential of the proposed encryption technique.
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Designing acoustic scattering elements using machine learning methods
PublikacjaIn the process of the design and correction of room acoustic properties, it is often necessary to select the appropriate type of acoustic treatment devices and make decisions regarding their size, geometry, and location of the devices inside the room under the treatment process. The goal of this doctoral dissertation is to develop and validate a mathematical model that allows predicting the effects of the application of the scattering...
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FPGA Based Real Time Simulations of the Face Milling Process
PublikacjaThe article presents a successful implementation of the milling process simulation at the Field-Programmable Gate Array (FPGA). By using FPGA, very rigorous Real-Time (RT) simulation requirements can be met. The response time of the FPGA simulations is significantly reduced, and the time synchronization is better than in a typical RT system implemented in software. The FPGA-based approach is characterized by enormous flexibility...
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Numerical simulation of temperature distribution of heat flow on reservoir tanks connected in a series
PublikacjaThe flow of temperature distribution through a medium in thermodynamic studies plays an important role in understanding physical phenomena in chemical science and petroleum engineering, while temperature distribution indicates the degree of reaction that must be undergone to obtain the final product. Therefore, this paper aims to present and apply the exponential matrix algorithm (EMA), differential transformation algorithm (DTA),...
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Coarse-grained simulation - an efficient approach for studying motions of large proteins
PublikacjaOne of the most important challenges in performing Molecular Dynamics (MD) simulations of large protein complexes is to accommodate the model accuracy and the simulation timescale. Hitherto, for the most relevant dynamics of protein aggregates in an explicit aqueous environment, the timescale reachable for the all-atoms simulations is of hundreds of nanoseconds. This range is four to six orders of magnitude smaller than processes...
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Efficient knowledge-based optimization of expensive computational models using adaptive response correction
PublikacjaComputer simulation has become an indispensable tool in engineering design as they allow an accurate evaluation of the system performance. This is critical in order to carry out the design process in a reliable manner without costly prototyping and physical measurements. However, high-fidelity computer simulations are computationally expensive. This turns to be a fundamental bottleneck when it comes to design automation using numerical...
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Computer vision techniques applied for reconstruction of seafloor 3D images from side scan and synthetic aperture sonars data
PublikacjaThe Side Scan Sonar and Synthetic Aperture Sonar are well known echo signal processing technologies that produce 2D images of the seafloor. Both systems combines a number of acoustic pings to form a high resolution image of seafloor. It was shown in numerous papers that 2D images acquired by such systems can be transformed into 3D models of seafloor surface by algorithmic approach using intensity information, contained in a grayscaled...
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Shaping of the workpiece surface in single-disc lapping
PublikacjaShape errors of the tool exert a dominant influence on the shape accuracy of the workpiece. The correlation between flatness errors of the lap and flatness errors of the workpieces was checked experimentally and determined analytically. Computer model of the workpiece shaping by lapping was developed. Evaluation method of the workpiece orientation as well as some simulation results for a lap with shape errors of convexity and cincavity...
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Modeling energy consumption of parallel applications
PublikacjaThe paper presents modeling and simulation of energy consumption of two types of parallel applications: geometric Single Program Multiple Data (SPMD) and divide-and-conquer (DAC). Simulation is performed in a new MERPSYS environment. Model of an application uses the Java language with extension representing message exchange between processes working in parallel. Simulation is performed by running threads representing distinct process...
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Experimental Study of Silent Sonar
PublikacjaStealth is a frequent requirement in military applications and involves the use of devices whose signals are difficult to intercept or identify by the enemy. The silent sonar concept was studied and developed at the Department of Marine Electronic Systems of the Gdansk University of Technology. The work included a detailed theoretical analysis, computer simulations and some experimental research. The results of the theoretical...
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Errors in the analysis of series resonant inverter/converter assuming sinusoidal waveforms of voltage and current
PublikacjaIn this paper the theory and simulation results of the series resonant inverter / converter are presented. In this work the authors carried out a detailed comparative analysis of results obtained using the method of AC analysis in the steady state for the first harmonic with the results of computer simulation. The AC analysis under certain conditions can lead to errors disqualifying this method. In particular, these errors appear...
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Control System Design for Dynamic Positioning using Vectorial Backstepping
PublikacjaThe problem of synthesis a dynamic positioning system for low frequency model of surface vessel was considered in this paper. The recursive vectorial backstepping control design was used to keep a fixed position and heading in presence of wave disturbances. The passive observer was introduced to smooth the measurements and to estimate the velocities needed for the control algorithm. The computer simulation results were given to...
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Quaternion Encryption Method for Image and Video Transmission
PublikacjaQuaternions are hyper-complex numbers of rank 4. They are often applied to mechanics in 3D space and are considered to be one of the best ways of representing rotations. In this paper a quaternion encryption method, based on algorithm by Nagase et al. (2004) has been proposed. According to a computer-based simulation the results of the performed research yield a high level of security, which is additionally strengthened by the...
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Image projection in Immersive 3D Visualization Laboratory
PublikacjaIn recent years, many centers in the world attempted to build a virtual reality laboratory. The main idea of such laboratory is to allow the user to “immerse” into and move in a computer-generated virtual world. In the paper, the underlying principles of the system of virtual reality (VR) are described. The selected implementations constructed by the research centers of the world are also presented. The cave automatic virtual environment...
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Ship’s de-perming process using coils lying on seabed
PublikacjaA ship built from ferromagnetic steel disturbs the uniformity of the Earth’s magnetic field. Changes of ship’s signature are due to the magneto-mechanical interaction of the hull with the Earth’s magnetic field. The ship’s magnetic field can be detected by a magnetic naval mine. For this reason, the vessel has to be demagnetized. There are several methods of ship’s de-perming. The results of experimental and computer simulations...
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Mathematical Modelling of Drive System with an Elastic Coupling Based on Formal Analogy between the Transmission Shaft and the Electric Transmission Line
PublikacjaIn the paper, the kinematic structure of the transmission shaft between the driving motor and the working mechanism is studied. The analysis is based on electrical and mechanical similarities. The equivalent circuits, typical for electrical systems, are defined for the transmission shaft concerned. Modelling of the transmission shaft based on a formal analogy between the transmission shaft and the electric transmission line is...
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Silent Sonar with matched filtration
PublikacjaRadars with continuous wave frequency (CW FM sonars) are used in radiolocation as 'silent sonars'. They determine the distance to target by measuring the difference between the frequency of the sounding signal and echo signal. The article presents the principle of operation and parameters of silent CW FM sonars. Target distance determined by these sonars is based on the signal at the output of the matched filter. The Doppler effect...
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Young’s modulus distribution in the FEM models of bone tissue
PublikacjaThis paper presents how differences of Young’s modulus in adjacent finite elements typical for organic materials such as bone tissue, influence stress calculating. Emphasizing high computational cost of variable Young’s modulus in parts of the model, where the number of finite elements has been raised, the authors wants to prove that new model of finite element which has variable Young’s modulus in its volume needs to be created....
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Modelling of sequencing batch reactor operating at various aeration modes
PublikacjaThe presented study involved designing a computer model of a sequencing batch reactor (SBR) at laboratory scale. The data pertaining to the technical aspects of the bioreactor and quality indicators of wastewater constituted the input for the employed simulation tool, i.e. GPS-X software package. The results of a simulation involving a 12-hour operation cycle are presented in this work; each cycle included 6 phases: filling, mixing,...
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Software for calculation of noise maps implemented on the supercomputer
PublikacjaThis paper presents investigation results relevant to the implementation of the algorithms for the calculation of noise maps. The aim of the implementation of the algorithms on the computer cluster is explained. Selected implementation details of the software called the noise propagation model are described. The interaction of the software with the data acquisition system is presented. Noise maps obtained by exploitation of the...
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FEM ANALYSIS AND EXPERIMENTAL TESTS OF RIGID RISER HANGING SYSTEM
PublikacjaThe article presents the analysis, project, and experimental examination of an original rigid riser for Coil Tubing Pipes. The principle of riser operation is based on the use of friction forces. The research included the FEM analysis of the designed riser, calculations of the required bolt tensions, and checking the effect of the clamping force on stress distribution in the pipeline. The results of computer simulation were verified...
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Influence of statistical errors on damage detection based on structuralflexibility and mode shape curvature
PublikacjaDamage detection procedures based on measured natural frequencies and building structure mode shapes are discussed in this paper. Modal curvature and structural flexibility approaches are tested. Attention is paid to the modal identification errors that influence damage detection. This problem is studied using a computer simulation of a simple supported beam. For practical cases, the peak picking methodand its statistical errors...
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Distribution Transformer with Multi-Zone Voltage Regulation for Smart Grid System Application
PublikacjaThe article presents four concepts of the multi-zone voltage regulation (MZVR) system. It is a combination of a distribution transformer with an on-load tap-changer, for step voltage regulation, and a power electronic converter, dimensioned for a fraction of MZVR power, realizing continuous voltage regulation, supplemented by a special switch, the so-called bypass. This allows voltage regulation at high resolution, wide range and...
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Kamil Andrzej Rybacki mgr inż.
OsobyBorn on 23 October 1993 in Gdańsk. In 2017, I have received the M.Sc. Degree at the Faculty of Applied Physics and Mathematics, Gdańsk University of Technology, Poland. My main fields of interest include computer simulations of molecular systems, parallel computing in application to computational physics methods and development of various simulation software. Currently, my research is focused on the development of hybrid Molecular...
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Scalable Maintenance of Address Mapping and Autodetecion in Environments Where Agents are Uncapable of Self-Registration
PublikacjaWhen working with multi-agent systems it is often desirable to manage the agent set. The existing methods of central monitoring stems from two different fields of application. The first has its roots in in computer network monitoring, the other in mutli-agent simulation environments. Both approaches are not general enough to cater for loosely controlled environments, where the total agent population is not known and often fluctuating,...
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Response Feature Technology for High-Frequency Electronics. Optimization, Modeling, and Design Automation
PublikacjaThis book discusses response feature technology and its applications to modeling, optimization, and computer-aided design of high-frequency structures including antenna and microwave components. By exploring the specific structure of the system outputs, feature-based approaches facilitate simulation-driven design procedures, both in terms of improving their computational efficiency and reliability. These benefits are associated...
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DETERMINATION OF ADDITIONAL TENSION IN TOWED STREAMER CABLE TRIGGERED BY COLLISION WITH UNDERWATER MOVING OBJECT
PublikacjaThe paper deals with issues connected with the behaviour of a streamer cable towed by a survey seismic vessel when the cable undergoes a strike triggered by collision with an underwater moving object. The consequences of such collisions may be both threat to the life of marine animals or damage to underwater units and large economic losses suffered by vessel owners. The risk of such collisions has increased over the last years...