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Search results for: MODELLING%20SIMULATION%20AND%20OPTIMIZATION
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Anomalous diffusion modeling using ultracapacitors in domino ladder circuit
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Understanding the Ukrainian Migrants Challenges in the EU: A Topic Modeling Approach
PublicationConfronted with the aggression against Ukraine in 2022, Europe faces one of the most important humanitarian challenges - the migration of war refugees from Ukraine, most of them women with children and the elderly. Both international institutions such as the European Union and the United Nations, but also national governments and, above all, local governments, which are the main providers of services and resources for refugees,...
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Soft modeling support for managing knowledge-based information technology (IT)
PublicationW pracy omówiono metody miękkiego modelowania. Wskazano na możliwości zastosowania tych metod do wspomagania tworzenia systemów opartych na wiedzy. Omówiono także metody oparte na teorii zbiorów rozmytych.
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Limitations of WSSUS modeling of stationary underwater acoustic communication channel
PublicationPerformances of underwater acoustic communication (UAC) systems are strongly related to specific propagation conditions of the underwater channel. Due to their large variability, there is a need for adaptive matching of the UAC systems signaling to the transmission properties of the channel. This requires a knowledge of instantaneous channel characteristics, in terms of the specific parameters of stochastic models. The wide-sense...
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Computational Approaches to Modeling Artificial Emotion – An Overview of the Proposed Solutions
PublicationCybernetic approach to modeling artificial emotion through the use of different theories of psychology is considered in this paper, presenting a review of twelve proposed solutions: ActAffAct, FLAME, EMA, ParleE, FearNot!, FAtiMA, WASABI, Cathexis, KARO, MAMID, FCM, and xEmotion. The main motivation for this study is founded on the hypothesis that emotions can play a definite utility role of scheduling variables in the construction...
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Temperature-dependent structure-property modeling of viscosity for ionic liquids
PublicationIn this paper we present the methodology for assessing the ionic liquids' viscosity at six temperature points (25, 35, 45, 50, 60 and 70 [C]), which utilizes only the in silico approach. The main idea of such assessment is based on the "correction equation" describing the correlation between experimentally measured viscosity and theoretically derived density (calculated with use of molecular mechanics), given at 6 different temperature...
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Performance and Power-Aware Modeling of MPI Applications for Cluster Computing
PublicationThe paper presents modeling of performance and power consumption when running parallel applications on modern cluster-based systems. The model includes basic so-called blocks representing either computations or communication. The latter includes both point-to-point and collective communication. Real measurements were performed using MPI applications and routines run on three different clusters with both Infiniband and Gigabit Ethernet...
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Modeling of conducted emission of dc-dc switch-mode converter
PublicationW publikacji zaprezentowano sposób modelowania i wyznaczania emisji przewodzonej zaburzeń elektromagnetycznych w przekształtnikach energoelektronicznych. Na przykładzie przekształtnika DC-DC, zostały dobrane odpowiednie narzędzia CAD do szerokopasmowego modelowania i symulacji przekształtnika energoelektronicznego. Otrzymane rezultaty zostały eksperymentalnie potwierdzone i porównane zarówno w dziedzinie czasu jak i częstotliwości...
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Numerical modeling of force and contact networks in fragmented sea ice
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Molecular Modeling of Interaction of the Vasopressin Analogs with Vasopressin and Oxytocin Receptors
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Modeling of broadband light source to use with optical coherenttomography system
PublicationW pracy przedstawiono modelowanie źródeł szerokopasmowych na potrzeby systemów koherentnej tomografii optycznej z punktu widzenia uzyskiwanej zdolności podłużnej i jakości otrzymywanych obrazów. Pokazano na przykładzie źródła szerokopasmowego wykorzystującego światłowód fotoniczny do generacji w wyniku zjawisk nieliniowych ''supercontinuum'' wpływ kształtowania wiązki na możliwości pomiarowe systemu OCT.
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Modeling of production planning and control process consistent with theory of constraint
PublicationArtykuł dotyczy problematyki zastosowania metody werbel-bufor-lina do planowania produkcji w systemach produkcyjnych z wielokrotnymi buforami. W artykule przedstawiono algorytm - jego funkcje, dane wejściowe i wyjściowe - który może mieć zastosowanie do modelowania procesu planowania i sterowania produkcją. Algorytm umożliwia określenie wielkości czasowych buforów w systemie oraz terminów rozpoczęcia i zakończenia realizacji zadań....
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Application of PL-Grid Platform for Modeling of the Selected Acoustic Phenomena
PublicationDomain grids are specific computational environments, developed within the PLGrid Plus project. For the Acoustic domain grid two supercomputer grid based services were prepared. Dedicated software consists of the outdoor sound propagation module and psychoacoustical noise dosimeter. The results are presented in a form of maps of sound level and Temporary Threshold Shift (TTS) values, therefore the services may play an informative...
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Urban noise propagation modeling in the Multimedia Noise Monitoring System
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Modeling of textural anisotropy in granular materials with micro-polar hypoplasticity
PublicationW artykule przedstawiono wyniki numerycznej wpływu anizotropii strukturalnej w materiałach granulowanych na powstawanie lokalizacji odkształceń. Obliczenia wykonano dla ściskania w płaskim stanie odkształcenia stosując metodę elementów skończonych na bazie mikropolarnego prawa hipoplastycznego. Wpływ anizotropii modelowano stosując skorelowane pola początkowego wskaźnika porowatości.
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Modeling of generator performance of BLDC machine using mathematica software
PublicationW artykule porównano trzy modele maszyny bezszczotkowej prądu stałego z magnesami trwałymi(BLDC) w przypadku pracy prądnicowej. Najprostszy model qd0 sprowadzono do dwóch osi prostopadłychzwiązanych z wirnikiem [3]. Zakłada on sinusoidalny rozkład pola w szczelinie. Model opisany wosiach naturalnych wyprowadzono w oparciu o formalizm Lagrnage'a [4] i moŜe uwzględniać dowolnyrozkład pola wzbudzonego przez magnesy trwałe. Model pośredni...
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FEM modeling of structures based on close range digital photogrammetry
PublicationPraca dotyczy metodologii przygotowania modelu konstrukcji istniejącej do analizy mechanicznej metodą element ow skończonych. MOdelowanie geometrii budowli jest oparte na danych pozyskanych z pomiarów fotogrametrycznych. Praca wskazuje na możliwości oraz efektywność zastosowania metod optometrycznych w rewitalizacji budowli zabytkowych, an przykładzie modelu dachu drewnianego.
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Modeling of Ozonation of Reactive Black 5 Through a Kinetic Approach
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Modeling the Influence of Salts on the Critical Micelle Concentration of Ionic Surfactants
PublicationWe show for the first time that a phenomenological, augmented volume-based thermodynamics (aVBT) model is capable to predict the critical micelle concentrations of ionic surfactants, including ionic liquids, with added salts. The model also adjusts for the type of salt added by including its molecular volume, which might form a connection to the Hofmeister effect. The other physico-chemically relevant quantities included in the...
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GROUP COMPOSER - System for Modeling Agents’ Team Building for Tasks
PublicationMulti-agent systems consist of many autonomous units, called agents, that can interact when trying to achieve their goals. The selection of interaction partners is called team formation. Three basic approaches can be considered to match multi-agent system resources to the problem at hand. To research the properties of different approaches, a software for modeling team formation in multi-agent systems has been created and is presented...
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Improving performance of large thrust bearings through modeling and experimentation
PublicationLarge thrust bearings are highly loaded machine elements and their failures cause serious losses. Start ups and stoppages of the bearing under load are specially critical regimes of operation. Load carrying capacity depends on the profile of the oil gap. In transient states this profile is also changing. In the design of large thrust bearings minimizing thermo-elastic deformations is an important goal, which can be accomplished...
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Accurate modeling of quasi-resonant inverter fed IM drive
PublicationIn this paper wide-band modeling methodology of a parallel quasi-resonant dc link inverter (PQRDCLI) fed induction machine (IM) is presented. The modeling objective is early-design stage prediction of conductive electromagnetic interference (EMI) emissions of the considered converter fed IM drive system. Operation principles of the selected topology of PQRDCLI feeding IM drive are given. Modeling of the converter drive system is...
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New approach to railway noise modeling employing Genetic Algorithms
PublicationMain goal of this paper was to describe an innovative method of noise prediction based on Genetic Algorithms. First part of the paper addresses the problem of growing noise, mainly in the context of a unified method for measuring noise. Further, Genetic Algorithms are described with regards to their fundamental features. Further a description is provided as to how Genetic Algorithms were used in the area of noise modeling. Next...
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Thermodynamic modeling of combustion process of the internal combustion engines – an overview
PublicationThe mathematical description of combustion process in the internal combustion engines is a very difficult task, due to the variety of phenomena that occurring in the engine from the moment when the fuel-air mixture ignites up to the moment when intake and exhaust valves beginning open. Modeling of the combustion process plays an important role in the engine simulation, which allows to predict incylinder pressure during the combustion,...
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Modeling of a Combined Cycle Gas Turbine Integrated with an Adsorption Chiller
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Assessment of chemical‐crosslink‐assisted protein structure modeling in CASP13
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Modeling of Wireless Traffic Load in Next Generation Wireless Networks
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Modeling of luminance distribution in CAVE-type virtual reality systems
PublicationAt present, one of the most advanced virtual reality systems are CAVE-type (Cave Automatic Virtual Environment) installations. Such systems are usually consisted of four, five or six projection screens and in case of six screens arranged in form of a cube. Providing the user with a high level of immersion feeling in such systems is largely dependent of optical properties of the system. The modeling of physical phenomena plays nowadays...
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Modeling of lapping plate wear and conditioning in single-sided lapping
PublicationIn order to achieve higher quality on worked surfaces with lower roughness, very high accuracy of shape and dimensions it is crucial to improve conventional finishing technologies and to develop new working principles. Single-sided lapping is one of the most effective planarization technologies and it is determined by a number of factors and boundary conditions. The most significant influence over a dimensional and profile accuracy,...
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Modeling the impact of surface currents in a harbor using graph theory
PublicationEnsuring security in a harbor requires research into its infrastructure using spatial environmental data. This paper presents a methodology that defines the design of a graph for modeling the interactions between surface currents and moving objects. Combining this graph with port charts that integrate electronic navigation charts with coastal orthophotographs allows us to perform a multidimensional analysis. In addition, the complete...
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Applicability of an effective conductivity approach in modeling thoracic impedance changes
PublicationThis paper describes numerical simulations of the influence of conductivity changes inside a volume conductor on impedance changes measured on its surface. A simple model based on the finite element method has been developed to estimate an applicability of the effective conductivity theory in human chest modeling. The model consisted of a cylinder with two concentric spheres inside. Simulations were performed for two cases: first...
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Modeling of traffic safety indictors on Polish national road network
PublicationAlthough decreased from 2001 to 2013, Poland’s road deaths improved at a slower rate than the rest of the EU, leaving Poland as one of the worst road safety performing countries in the EU. The national road network in Poland, despite the dynamic transformation and development, still does not conform to the EU safety standards. Similar situation exists in other EU countries, particularly those in Central and Eastern Europe. Safety...
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Modeling of multi-cavity Fabry-Perot optical fiber sensors
PublicationReflectance characteristics of a two-cavity extrinsic Fabry-Perot optical fiber sensor were investigated using computer modeling. Calculations were performed using a plane wave-based approach, selected for clarity of results. Based on the modeling results, it can be concluded that the two-cavity Fabry-Perot interferometer can be used to measure two different quantities, such as refractive index and temperature, independently. It...
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Modeling of Ice Passage Through Reservoirs System on the Vistula River
PublicationNumerical model was used to assess ice passage through proposed reservoir on the lower Vistula River. Model results were compared with observation on the Vistula River, but because the dam is not constructed yet, the direct comparison was not possible. The study focused on ice movement and accumulation in the reservoir for variety of low flow condition with and without wind effect. Bridge’s piers in the upper part of the reservoir...
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Numerical modeling of sound intensity distributions around acoustic transducer
PublicationThe aim of this research study is to measure, simulate and compare sound intensity distribution generated by the acoustic transducers of the loudspeaker. The comparison of the gathered data allows for validating the numerical model of the acoustic radiation. An accurate model of a sound source is necessary in mathematical modeling of the sound field distribution near the scattering obstacles. An example of such obstacle is a human...
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Analytical modeling of electric drives for vehicle traction control systems
PublicationWheel-torque control bandwidth in vehicle dynamics model is crucial in evaluating optimal tracking ability of tire slip and in analysis of control system stability. Electric drives’ control dynamics are influenced by timing of digital control events, e.g. by sampling instant of motor currents. Reflecting this timing in drive analytical models is therefore important for analysis of vehicle traction systems. The paper considers five...
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Modeling the global atmospheric transport and deposition of mercury to the Great Lakes
PublicationMercury contamination in the Great Lakes continues to have important public health and wildlife ecotoxicology impacts, and atmospheric deposition is a significant ongoing loading pathway. The objective of this study was to estimate the amount and source-attribution for atmospheric mercury deposition to each lake, information needed to prioritize amelioration efforts. A new global, Eulerian version of the HYSPLIT-Hg model was used...
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Determinants of the Internationalization of Family Firms - a Structural Eqquation Modeling Analysis
PublicationCurrently, international behaviors of family businesses (FBs) attract a growing interest of researchers. In an increasingly competitive environment, numerous FBs are forced to expand into foreign markets in search for ways to survive or grow. The article is both theoretical and empirical. In the theoretical part it presents theoretical concepts of FBs internationalization, especially determinants for their going international....
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Modeling of truss with cold-formed section and positive eccentricity in the node
PublicationThis work is dedicated to establishing the load carrying capacity of tensed and compressed truss’ nodes made of cold-formed open cross sections. The occurrence of bending in the truss’ nodes is the result of a specific production technology for system lattice girders assumed by the designer and the producer. The aim of this research is to present the methodology of conduct for creation of computational models that best depict the...
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Design and modeling of the piezoelectric motor based on three resonance actuators
PublicationThis paper describes a piezoelectric motor which combines advantages from two existing piezoelectric motors topologies. The research work presents the design, simulations and measurements of the piezoelectric motor with three rotation-mode actuators. The aim of the project was to obtain the high speed piezoelectric motor. Other advantages of this conception are blocking torque, short response times, the ability to work in a hostile...
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Reliable Microwave Modeling By Means of Variable-Fidelity Response Features
PublicationIn this work, methodologies for low-cost and reliable microwave modeling are presented using variable-fidelity response features. The two key components of our approach are: (i) a realization of the modeling process at the level of suitably selected feature points of the responses (e.g., S-parameters vs. frequency) of the structure at hand, and (ii) the exploitation of variable-fidelity EM simulation data, also for the response...
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Characterization of Defects Inside the Cable Dielectric With Partial Discharge Modeling
PublicationThe continuous monitoring of power system devices is an important step toward keeping such capital assets safe. Partial discharge (PD)-based measurement tools provide a reliable and accurate condition assessment of power system insulations. It is very common that voids or cavities exist in every solid dielectric insulation medium. In this article, different voids are modeled and analyzed using an advanced finite element (FE)-based...
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Electromagnetic Modeling of Microstrip Elements Aided with Artificial Neural Network
PublicationThe electromagnetic modeling principle aided withartificial neural network to designing the microwave widebandelements/networks prepared in microstrip technology is proposedin the paper. It is assumed that the complete information is knownfor the prototype design which is prepared on certain substratewith certain thickness and electric permittivity. The longitudinaland transversal dimensions of new design...
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Mispronunciation Detection in Non-Native (L2) English with Uncertainty Modeling
PublicationA common approach to the automatic detection of mispronunciation in language learning is to recognize the phonemes produced by a student and compare it to the expected pronunciation of a native speaker. This approach makes two simplifying assumptions: a) phonemes can be recognized from speech with high accuracy, b) there is a single correct way for a sentence to be pronounced. These assumptions do not always hold, which can result...
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SIMPLIFIED MODELING OF STRESS AND DEFLECTION LIMIT STATES OF UNDERGROUND TANKS
PublicationFuel tanks are designed with regard to standard actions and operating conditions. The work analyses the impact of corrosion and other means to variation of stresses and deformation of a horizontal underground tank shell. The computations are preliminary. Due to the long computational time of the entire tank the analysis is restricted to its part only. The full analysis is bound to assess structural reliability, further allowing...
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Two-Stage Variable-Fidelity Modeling of Antennas with Domain Confinement
PublicationSurrogate modeling has become the method of choice in solving an increasing number of antenna design tasks, especially those involving expensive full-wave electromagnetic (EM) simulations. Notwithstanding, the curse of dimensionality considerably affects conventional metamodeling methods, and their capability to efficiently handle nonlinear antenna characteristics over broad ranges of the system parameters is limited. Performance-driven...
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Systems, Environments, and Soliton Rate Equations: Toward Realistic Modeling
PublicationIn order to solve a system of nonlinear rate equations one can try to use some soliton methods. The procedure involves three steps: (1) find a ‘Lax representation’ where all the kinetic variables are combined into a single matrix ρ, all the kinetic constants are encoded in a matrix H; (2) find a Darboux–Bäcklund dressing transformation for the Lax representation iρ˙=[H,f(ρ)], where f models a time-dependent environment; (3) find...
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A Novel Approach to Fully Nonlinear Mathematical Modeling of Tectonic Plates
PublicationThe motion of the Earth's layers due to internal pressures is simulated in this research with an efficient mathematical model. The Earth, which revolves around its axis of rotation and is under internal pressure, will change the shape and displacement of the internal layers and tectonic plates. Applied mathematical models are based on a new approach to shell theory involving both two and three-dimensional approaches. It is the...
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Wideband Modeling of DC-DC Buck Converter with GaN Transistors
PublicationThe general wideband modeling method of the power converter is presented on the example of DC-DC buck converter with GaN High Electron Mobility Transistors (HEMT). The models of all basic and parasitic components are briefly described. The two methods of Printed Circuit Board (PCB) layout parameter extraction are presented. The results of simulation in Saber@Sketch simulation software and measurements are compared. Next, the model...
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Modeling the Structure, Dynamics, and Transformations of Proteins with the UNRES Force Field
PublicationThe physics-based united-residue (UNRES) model of proteins ( www.unres.pl ) has been designed to carry out large-scale simulations of protein folding. The force field has been derived and parameterized based on the principles of statistical-mechanics, which makes it independent of structural databases and applicable to treat nonstandard situations such as, proteins that contain D-amino-acid residues. Powered by Langevin dynamics...