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Wyniki wyszukiwania dla: simulation of pneumatic drive
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Speed sensorless induction motor drive with motor choke and predictive control
PublikacjaArtykuł przedstawia układ napędowy z silnikiem indukcyjnym, zasilanym z falownika napięcia przy zastosowaniu filtru silnikowego. System pracuje bez czujnika prędkości obrotowej. Głównym aspektem pracy jest zwrócenie uwagi na to, że zastosowanie dławika silnikowego wymaga odpowiednich zmian w strukturach sterowania i estymacji zmiennych. Zaproponowano odpowiednie rozwiązanie dla układu napędowego z regulatorem predykcyjnym prądu....
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Automatic control systems for ships fitted with podded propulsion drive (POD).
PublikacjaW artykule ukazano celowość i możliwości automatyzacji układów napędowych, zwłaszcza typu POD, przewidzianych do zastosowania na projektowanych w ramach projektu Eureka BALTECOLOGICAL SHIP czterech statkach bałtyckich: kontenerowca, pojazdowa i tankowca oraz statku rzeczno - morskiego. Zawarte w artykule informacje ułatwiają dokonanie wyboru właściwych założeń projektowanego układu sterowania napędem wymienionych wyżej statków.
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Thermo-Mechanical Simulation of Underwater Friction Stir Welding of Low Carbon Steel
PublikacjaThis article investigates the flow of materials and weld formation during underwater friction stir welding (UFSW) of low carbon steel. A thermo-mechanical model is used to understand the relation between frictional heat phenomena during the welding and weld properties. To better understand the effects of the water environment, the simulation and experimental results were compared with the sample prepared by the traditional friction...
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COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION
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International Journal of Tomography and Simulation
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Journal of Building Performance Simulation
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Journal of Computational Simulation and Modeling
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International Journal of Modelling and Simulation
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JOURNAL OF STATISTICAL COMPUTATION AND SIMULATION
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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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Building Simulation
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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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Simulation Results of Dynamic Capacity Reallocation in Hierarchical Cell Structure of UMTS Network
PublikacjaIn the paper simulation results of dynamic capacity reallocation between different layers of hierarchical cell structure of UMTS network has been described. This approach for load management seems to be useful for improving the resource utilization perfmorance.
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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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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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Simulation of the Dynamics of Renewable Energy Sources with Energy Storage Systems
PublikacjaThe intermittency of renewable energy sources (RES) constitutes a challenge for effective power system control. Fossil-fuel-based units offering ancillary power services to meet the short-term power imbalance are a financial and environmental burden for the society. Energy storage systems (ESS) can be the solution in view of the electricity market development and growing environmental concern. The major questions are, in what circumstances...
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Simulation of influence of the air gap asymmetryon voltage waveforms of a synchronous machine
PublikacjaResults of simulation of a synchronous generator with the air gap asymmetry characterised by eccentricity are presented in the paper. The Lagrange's energy method has been used in derivation of the model equations. Analysis of influence of the air gap asymmetry on characteristics of self and mutual inductances of windings, as well as analysis of induced voltage waveforms as a function of the air gap asymmetry have been performed....
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Numerical simulation of grouding experiment
PublikacjaJednym z możliwych sposobów zwiększenia odporności kon strukcji statku na kolizje jest zaprojektowania jej w taki sposób, aby podczas zderzenia absorbowała możliwie dużą ilość energii. Jednym z nowych pomysłów jest idea, będąca tematem projektu CORET (EUREKA E!3614), zwiększenia odporności na rozdarcie poszycia poprzez dodanie do obecnej konstrukcji półelastycznej polimerowo-betonowej bariery ochronnej. Proces projektowania nowej...
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Simulation of incremental encoder signals
PublikacjaPrzedstawiono generator sygnału impulsowego do symulacji sygnału z przetwornika obrotowo-impulsowego w stanach przejściowych. Omówiono algorytmy wyznaczenia przedziałów międzyimpulsowych dla trzech rodzajów zmian prędkości obrotowej: liniowej, wykładniczej oraz sinusoidalnej. Przeanalizowano błędy kwantowania wynikające z cyfrowej realizacji generatora.
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Teaching simulation methods in a university
PublikacjaZmiany, jakie zachodzą we współczesnym środowisku gospodarczym wymagają od menedżerów stosowania narzędzi umożliwiających identyfikację pojawiających się szans i zagrożeń oraz wspomagających procesy podejmowania decyzji. Symulacje komputerowe było stosowane przez firmy już w latach pięćdziesiątych w celu rozwiązywania problemów z zakresu zwiększenia wydajności, obniżki kosztów czy też zwiększenia dochodowości . Współcześnie modelowanie...
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Experimental study and numerical simulation of the dynamic penetration into dry clay
PublikacjaTests of dry clay were carried out in a uniaxial stress state using the experimental setup which implements the split Hopkinson pressure bar method. Based on the results of these experiments, the compressive strength of clay was determined as an important element of S.S. Grigoryan’s model of the soil medium. In addition, the parameters of this model are determined from the results of experiments using the modified Kolsky method...
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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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Electrochemical simulation of enzymatic transformations studied for the selected antitumor acridine derivatives
PublikacjaThe elucidation of the metabolic pathways and the biotransformation mechanisms of potential drugs is a crucial point in drug development. It allows to know the activation routes of the new biologically active compounds, especially in respect to their possible toxicity. Generally, in vivo or in vitro experiments with liver microsomes or hepatocytes are performed. However, these testing schemes are tedious, time consuming and of...
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A Simulation Model for Risk and Pricing Competition in the Retail Lending Market
PublikacjaWe propose a simulation model of the retail lending market with two types of agents: borrowers searching for low interest rates and lenders competing through risk-based pricing. We show that individual banks observe adverse selection, even if every lender applies the same pricing strategy and a credit scoring model of comparable discrimination power. Additionally, the model justifies the reverse-S shape of the response rate curve....
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Speed and load torque observer application in high-speed train electric drive
PublikacjaW artykule przedstawiono zastosowanie diagnostyczne obserwatorów prędkości obrotowej i momentu obciążenia w układzie napędowym z silnikiem asynchronicznym. System diagnostyczny jest dedykowany do napędu pociągu szybkiego. Celem diagnostycznym jest monitorowanie stanu czujnika prędkości obrotowej wału silnika oraz układu przeniesienia momentu trakcyjnego. Analiza sygnałów obliczanych w obserwatorach stanu pozwala na wykrycie uszkodzeń...
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Increases in leptin levels, sympathetic drive, and weight gain in obstructive sleep apnea
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Transient torsional vibrations control in the geared drive trains of the hot rolling mills
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Analysis of Interspike-Intervals for the General Class of Integrate-and-Fire Models with Periodic Drive
PublikacjaWe study one-dimensional integrate-and-fire models of the general type x˙=F (t, x) and analyze properties of the firing map which iterations recover consecutive spike timings. We impose very week constraints for the regularity of the function F (t, x), e.g. often it suffices to assume that F is continuous. If additionally F is periodic in t, using mathematical study of the displacement sequence of an orientation preserving circle...
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Application of renewable energy sources to drive organic Rankine cycle micro CHP
PublikacjaOdnawialne źródła energii rzadko znajdują zastosowanie przy stawianych obecnie wymaganiach przez nowoczesne ciepłownie. Pojawiła się unikalna okazja pomocy przy wprowadzeniu na rynek elektrowni zoptymalizowanej dla tych nieużywanych i pomijanych źródeł ciepła. Organiczny obieg Rankine'a jest podobny do konwencjonalnych turbin parowych, wyjątkiem jest płyn napędzający turbinę, którym jest płyn roboczy o dużej masie cząsteczkowej....
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Improving Control Dynamics of PMSM Drive by Estimating Zero-Delay Current Value
PublikacjaDynamic performance of current control loop still remains crucial for position-, speed-, and torque-controlled drives. In the study, a current loop solution has been designed for field oriented control of permanent magnet synchronous motors (PMSM). It enhances typical PI controller with an estimator of zero-delay current (ZDC) value. The ZDC estimation allows for selecting substantially higher controller gain. It reduces control...
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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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Probabilistic sensitivity of the limit states of structures using Monte Carlom simulation
PublikacjaThe paper presents the concept of probabilistic sensitivity of structural limit states with respect to given design variables. A general idea is presented, illustrated by a simple case solved in an analytical way. More general approach is presented for the engineering structures, in this case a dedicated Monte Carlo simulation procedure is involved as part of the methodology. Illustration of the engineering case is done, by means...
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Hybrid fuzzy-ontological project framework of a team work simulation system
PublikacjaThe aim of this article is to present the project framework for constructing a Software Process Simulation Modeling (SPSM) system. SPSM systems can be used as a virtual environment for the selection of methods and tools of project management in IT support organizations. The constructed system simulates the Scrum methodology, including the management processes and the project roles. For the implementation of Scrum processes, the...
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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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Cardiovascular and Perceptual Responses to Resistance Training with Practical Blood Flow Restriction Induced by a Non-Elastic Band vs. Pneumatic Cuff: A Crossover Randomized Study
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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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Simulation of large thrust-bearing performance at transient states, warm and cold start-up
PublikacjaThe start-up of a large hydrodynamic thrust bearing of a vertical hydrogenerator is one of the most critical situations during the lifetime of a bearing. Hydrodynamic load capacity is low due to low speed and higher thermal deformations of the pad. A new approach to the simulation of a hydrodynamic bearing is shown in this article. A combination of finite elements method and computational fluid dynamics is used to perform the transient...
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Design of microstrip antenna subarrays: a simulation-driven surrogate-based approach
PublikacjaA methodology for computationally efficient simulation-driven design of microstrip antenna subarrays is presented. Our approach takes into account the effect of the feed (here, a corporate network) on the subarray side-lobe level and allows adjustment of both radiation and reflection responses of the structure under design within a single automated process. This process is realized as surrogate-based optimization that produces...
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Multi-source-supplied parallel hybrid propulsion of the inland passenger ship STA.H. Research work on energy efficiency of a hybrid propulsion system operating in the electric motor drive mode
PublikacjaIn the Faculty of Ocean Engineering and Ship Technology, Gdansk University of Technology, design has recently been developed of a small inland ship with hybrid propulsion and supply system. The ship will be propelled by a specially designed so called parallel hybrid propulsion system. The work was aimed at carrying out the energy efficiency analysis of a hybrid propulsion system operating in the electric motor drive mode and at...
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Simulation-Based Design of Microstrip Linear Antenna Arrays Using Fast Radiation Response Surrogates
PublikacjaFast yet accurate technique for simulation-based design of linear arrays of microstrip patch antennas is presented. Our technique includes: (i) optimization of the corrected array factor of the antenna array under design for a phase excitation taper resulting in reduced side lobes; (ii) simulation-driven optimization of the array element for element dimensions resulting in matching at and about operational frequency, and (iii)...
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Numerical simulation of cold flow and combustion in a swirl stabilized combustor
PublikacjaA numerical simulation model was developed to investigate the cold flow and combustion using Ansys FLUENT 2021R1. The governing equations were solved using the pressure-based method, and pressure–velocity coupling was performed using the SIMPLE method. To model the turbulent process, the RSM model was used. Non-premixed model is chosen to solve the chemical kinetics between fuel and oxigen. Radiation heat transfer was calculated...
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Hybrid Fuzzy-Ontological Project Framework of a Team Work Simulation System
PublikacjaThe aim of this article is to present the project framework for constructing a Software Process Simulation Modeling (SPSM) system. SPSM systems can be used as a virtual environment for the selection of methods and tools of project management in IT support organizations. The constructed system simulates the Scrum methodology, including the management processes and the project roles. For the implementation of Scrum processes, the...
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Implementation of high-precision computation capabilities into the open-source dynamic simulation framework YADE
PublikacjaThis paper deals with the implementation of arbitrary precision calculations into the open-source discrete element framework YADE published under the GPL-2+ free software license. This new capability paves the way for the simulation framework to be used in many new fields such as quantum mechanics. The implementation details and associated gains in the accuracy of the results are discussed. Besides the "standard" double (64 bits)...
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Effect of the working liquid compressibility on the picture of volumetric and mechanical losses in a high pressure displacement pump used in a hydrostatic drive. Part I Energy losses in a drive system, volumetric losses in a pump
PublikacjaŚciśliwość cieczy roboczej może znacząco zmienić wartości i proporcje współczynników strat objętościowych i mechanicznych w pompie wyporowej zastosowanej w układzie napędu hydrostatycznego. Wpływ ten jest szczególnie widoczny w trakcie pracy pod wysokim ciśnieniem a także wówczas, gdy występuje zapowietrzenie cieczy roboczej. W części I przedstawiono wykres zaproponowany przez autora, wzrostu mocy w układzie napędu hydrostatycznego...
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Effect of the working liquid compressibility on the picture of volumetric and mechanical losses in a high pressure displacement pump used in a hydrostatic drive. Part I Energy losses in a drive system, volumetric losses in a pump
PublikacjaŚciśliwość cieczy roboczej może znacząco zmienić wartości i proporcje współczynników strat objętościowych i mechanicznych w pompie wyporowej zastosowanej w układzie napędu hydrostatycznego. Wpływ ten jest szczególnie widoczny w trakcie pracy pod wysokim ciśnieniem a także wówczas, gdy występuje zapowietrzenie cieczy roboczej. W części I przedstawiono wykres zaproponowany przez autora, wzrostu mocy w układzie napędu hydrostatycznego...
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Simulation of signal acquisition from a rotary flowmeter
Dane BadawczeThe dataset contains results of simulation measuring the flow of homogeneous substances by rotational flow meter: a moment of impulse at the output of flow meter, time between successive pulses, number of pulses counted from standard generator and relative error of measurement.
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Mechanical simulation of artificial gravity in torus-shaped and cylindrical spacecraft
PublikacjaLarge deformations and stress analyses in two types of space structures that are intended for people to live in space have been studied in this research. The structure under analysis is assumed to rotate around the central axis to create artificial gravitational acceleration equal to the gravity on the Earth's surface. The analysis is fully dynamic, which is formulated based on the energy method by using the first-order shear deformation...
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Cost-efficient simulation-driven design of compact impedance matching transformers
PublikacjaIn this paper, an algorithmic framework for cost-efficient design optimization of miniaturized impedance matching transformers has been presented. Our approach exploits a bottom-up design that involves translating the overall design specifications for the circuit at hand to its elementary building blocks (here, compact microstrip resonant cells, CMRCs), as well as fast surrogate-assisted optimization of the cells followed by simulation-based...
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Modular high precision high current source for special applications — Simulation and verification
PublikacjaThis paper presents selected issues concerning realization of high precision high current source for special applications, where high demands of output parameters of such device are required. A new 80 kW prototype of modular high precision high current source is presented, where output current accuracy reaches 5x10-5. This paper presents also results of operation of the simulation model and of the prototype converter. In order...
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Long-term hindcast simulation of currents in the Baltic Sea
Dane BadawczeThe dataset contains the results of numerical modelling of currents over a period of 50 years (1958-2007) in the Baltic Sea . A long-term hindcast simulation was performed using a three-dimensional hydrodynamic model PM3D (Kowalewski and Kowalewska-Kalkowska, 2017), a new version of the M3D model (Kowalewski, 1997). The hydrodynamic model was coupled...