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wszystkich: 598
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Wyniki wyszukiwania dla: MATHEMATICAL MODELING AND COMPUTER SIMULATION
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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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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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Release of Encapsulated Bioactive Compounds from Active Packaging/Coating Materials and Its Modeling: A Systematic Review
PublikacjaThe issue of achieving controlled or targeted release of bioactive compounds with specific functional properties is a complex task that requires addressing several factors, including the type of bioactive, the nature of the delivery system, and the environmental conditions during transportation and storage. This paper deals with extensive reporting for the identification of original articles using Scopus and Google Scholar based...
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Multifrequency self-optimizing narrowband interference canceller
PublikacjaThe problem of cancellation of a nonstationary sinusoidal interference, acting at the output of a linear stable plant, is considered. It is assumed that disturbance is a multifrequency narrowband signal, and that system output is contaminated with wideband noise. It is not assumed that the reference signal is available. Two disturbance cancelling schemes are proposed, one for disturbances with unrelated frequency components, and...
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Synchronous generator model taking into account the non-uniform saturation of the pole shoes
PublikacjaFor the evaluation of modern electric power systems with regard to their behavior, weight, and reliability a novel modeling and simulation tools have been developed. The paper presents circuit model of synchronous generator taking into account both the non-sinusoidal distribution of the stator and rotor winding, and non-uniform saturation of the pole shoes. This model is suitable for simulation of both salient and no-salient pole...
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Operational Enhancement of Numerical Weather Prediction with Data from Real-time Satellite Images
PublikacjaNumerical weather prediction (NWP) is a rapidly expanding field of science, which is related to meteorology, remote sensing and computer science. Authors present methods of enhancing WRF EMS (Weather Research and Forecast Environmental Modeling System) weather prediction system using data from satellites equipped with AMSU sensor (Advanced Microwave Sounding Unit). The data is acquired with Department of Geoinformatics’ ground...
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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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Determination of Mathematical Model Parameters of a Medium Frequency Transformer
PublikacjaThe paper presents the results of experimental studies of the medium frequency transformer. The object of the research was a prototype of a single-phase transformer with a core made of ferrite I-core elements and windings made of Litz conductors. The research was carried out to determine the parameters of the transformer's mathematical model. The scope of the tests included determining the magnetic hysteresis loop and measuring...
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Non-Adaptive Speed and Position Observer of Doubly-Fed Induction Generator
PublikacjaThe non-adaptive speed and position estimation of a doubly-fed induction generator (DFIG) is presented in this paper. The speed observer is based on the mathematical model of DFIG and to stabilize the structure the Lyapunov method is used. The classic stator field-oriented control to active and reactive power control is used in the sensorless control system. The performance of the proposed algorithm of a speed observer is validated...
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Numerical Simulation of Catastrophic Flood: the Case Study of Hypothetical Failure of the Bielkowo Hydro–Power Plant Reservoir
PublikacjaThe numerical modeling of flood wave propagation following the hypo-thetical breaks of the embankments of the Bielkowo hydro–power plant storage reservoir (Kolbudy II Reservoir) on the Radunia River in Poland have been presented. The results of computations were used to estimate the parameters of the flood waves, which are indispensable for the flood zone determination and mapping and then for the flood risk analysis. When estimating...
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Expedited EM-Driven Design of Miniaturized Microwave Hybrid Couplers Using Surrogate-Based Optimization
PublikacjaMiniaturization of microwave hybrid couplers is important for contemporary wireless communication engineering. Using standard computer-aided design methods for development of compact structures is extremely challenging due to a general lack of computationally efficient and accurate simulation models. Poor accuracy of available equivalent circuits results from neglecting parasitic cross-couplings that greatly affect the performance...
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Low-Cost and Highly-Accurate Behavioral Modeling of Antenna Structures by Means of Knowledge-Based Domain-Constrained Deep Learning Surrogates
PublikacjaThe awareness and practical benefits of behavioral modeling methods have been steadily growing in the antenna engineering community over the last decade or so. Undoubtedly, the most important advantage thereof is a possibility of a dramatic reduction of computational expenses associated with computer-aided design procedures, especially those relying on full-wave electromagnetic (EM) simulations. In particular, the employment of...
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Application of mesh deformation for modeling of conformal RF components with 3D FEM
PublikacjaIn this paper, a method of analysis of conformal RF components has been proposed. In this approach, modeling of a curved structure is based on mesh deformation of planar objects rather than the construction of conformal geometry at CSG level. Since the model is represented as a 3D mesh, the deformation only requires the calculation of nodes position in the bent structure. The results of the proposed algorithm have been validated...
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Dynamiczna aplikacja Internetowa ASP.NET silnika indukcyjnego jako elementu wirtualnego laboratorium maszyn elektrycznych
PublikacjaTematem referatu jest dynamiczna aplikacja internetowa, która umożliwia symulację obwodową silnika indukcyjnego trójfazowego Sg 100 L2 z wykorzystaniem interfejsu przeglądarki WWW. Model matematyczny silnika jest zdefiniowany w tzw. osiach naturalnych i sformułowany na podstawie metody energetycznej Lagrange’a. Do implementacji modelu maszyny w aplikacji internetowej wybrano projekt typu Web Forms, który jest składnikiem środowiska...
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Analytical method of determining dynamic properties of thermocouples used in measurements of quick – changing temperatures of exhaust gases in marine diesel engines
PublikacjaThe article presents selected issues of mathematical modeling of heat exchange between the thermocouple and the exhaust gas flowing them, in unsteady conditions. On the way of energy balancing consideration of thermodynamic processes developed differential equations describing the dynamic properties for three versions of the design sheathed thermocouples: with weld isolated from the sheath, with weld welded the sheath and with...
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Combining Road Network Data from OpenStreetMap with an Authoritative Database
PublikacjaComputer modeling of road networks requires detailed and up-to-date dataset. This paper proposes a method of combining authoritative databases with OpenStreetMap (OSM) system. The complete route is established by finding paths in the graph constructed from partial data obtained from OSM. In order to correlate data from both sources, a method of coordinate conversion is proposed. The algorithm queries road data from OSM and provides...
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Modeling two phase flow in large scale fractured porous media with an extended multiple interacting continua method
PublikacjaWe present a two phase flow conceptual model, the corresponding simulator (2pMINC) and a workflow for large-scale fractured reservoirs, based on a continuum fracture approach which uses the multiple interacting continua (MINC) method complemented with an improved upscaling technique. The complex transient behavior of the flow processes in fractured porous media is captured by subgridding the coarse blocks in nested volume elements...
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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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Hydrodynamic Model of the New Waterway through the Vistula Spit
PublikacjaThe decision to build a new waterway (strait) in the Polish part of the Vistula Spit was made in 2017. The new connection between the Gulf of Gdańsk and the Vistula Lagoon is planned as an artificial navigable channel with a lock and a small port. During storm surges and wind tides in the gulf or in the lagoon, sluicing will be re-quired for vessels to tackle the Vistula Spit. This procedure does not require significant water flow...
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New data acquisition system for birch sap concentrate production using the reverse osmosis technology
PublikacjaThe work presents a simple electronic device that helps to monitor the basic parameters of the reverse osmosis (RO) system during the concentration of birch tree sap. The construction costs are low (around 150 Euro) but the functionality of the device is high. It has an in-build two channel conductometer and can measure the volumetric flow rate of two streams of liquids. The collected data are transmitted wirelessly via Bluetooth...
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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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Fuzzy Sets in the GIS Environment in the Location of Objects on the Surface of Water Bodies
PublikacjaThe issue presented here focuses on concerns about the localization of the object on water surface. The article shows how to facilitate localization process by applying mathematical solutions characterized by simplicity, rapid action and delivering credible results. The paper shows the results of background experiments, which enabled to collect technical parameters needed for conducting simulation testing. The research has been...
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Performance and Power-Aware Modeling of MPI Applications for Cluster Computing
PublikacjaThe 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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Performance-Based Nested Surrogate Modeling of Antenna Input Characteristics
PublikacjaUtilization of electromagnetic (EM) simulation tools is mandatory in the design of contemporary antenna structures. At the same time, conducting designs procedures that require multiple evaluations of the antenna at hand, such as parametric optimization or yield-driven design, is hindered by a high cost of accurate EM analysis. To certain extent, this issue can be addressed by utilization of fast replacement models (also referred...
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Reduced-Cost Microwave Modeling Using Constrained Domains and Dimensionality Reduction
PublikacjaDevelopment of modern microwave devices largely exploits full-wave electromagnetic (EM) simulations. Yet, simulation-driven design may be problematic due to the incurred CPU expenses. Addressing the high-cost issues stimulated the development of surrogate modeling methods. Among them, data-driven techniques seem to be the most widespread owing to their flexibility and accessibility. Nonetheless, applicability of approximation-based...
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A comprehensive approach to double inverted pendulum modelling
PublikacjaThe problem of mathematical modelling and indication of properties of a DIP has been investigated in this paper. The aim of this work is to aggregate the knowledge on a DIP modelling using the Euler-Lagrange formalism in the presence of external forces and friction. To indicate the main properties important for simulation, model parameters identification and control system synthesis, analytical and numerical tools have been used....
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Variable-fidelity CFD models and co-Kriging for expedited multi-objective aerodynamic design optimization
PublikacjaPurpose – Strategies for accelerated multi-objective optimization of aerodynamic surfaces are investigated, including the possibility of exploiting surrogate modeling techniques for computational fluid dynamic (CFD)-driven design speedup of such surfaces. The purpose of this paper is to reduce the overall optimization time. Design/methodology/approach – An algorithmic framework is described that is composed of: a search space reduction,...
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Triangulation-based Constrained Surrogate Modeling of Antennas
PublikacjaDesign of contemporary antenna structures is heavily based on full-wave electromagnetic (EM) simulation tools. They provide accuracy but are CPU-intensive. Reduction of EM-driven design procedure cost can be achieved by using fast replacement models (surrogates). Unfortunately, standard modeling techniques are unable to ensure sufficient predictive power for real-world antenna structures (multiple parameters, wide parameter ranges,...
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Finite element modeling of plastic hinges based on ductility demand-capacity method using nonlinear material for dynamic analysis
PublikacjaThe article discusses modeling plastic hinges in reinforced concrete interme-diate supports using finite elements methods. The ductility demand-capacitymethod was used to determine the geometrical parameters of cross-section plas-ticization zones, their ability to move and rotate, as well as their ductility. Dueto the varied geometry and stiffness of the supports and their nonlinear behav-ior under dynamic load, this method was...
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Flexomagneticity in buckled shear deformable hard-magnetic soft structures
PublikacjaThis research work performs the first time exploring and addressing the flexomagnetic property in a shear deformable piezomagnetic structure. The strain gradient reveals flexomagneticity in a magnetization phenomenon of structures regardless of their atomic lattice is symmetrical or asymmetrical. It is assumed that a synchronous converse magnetization couples both piezomagnetic and flexomagnetic features into the material structure....
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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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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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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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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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FEA analysis of the multicell piezoelectric motor
PublikacjaThe presented paper concerns a design, modeling and chosen tests of the prototype multicell piezoelectric motor (MPM). The principle of operation based on three independent traveling wave actuators is presented. The main materials and technologies used in the fabrication process are described. The structure of the motor is modeled using static and modal FEM analysis. The process of traveling wave generation in the MPM structure...
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On deterministic procedures for low-cost multi-objective design optimization of miniaturized impedance matching transformers
PublikacjaPurpose This paper aims to investigate deterministic strategies for low-cost multi-objective design optimization of compact microwave structures, specifically, impedance matching transformers. The considered methods involve surrogate modeling techniques and variable-fidelity electromagnetic (EM) simulations. In contrary to majority of conventional approaches, they do not rely on population-based metaheuristics, which permit lowering...
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Novel method of estimation of inertial and dissipative parameters of a railway pantograph model
PublikacjaAn increase in electric railway vehicles service velocity requires that correct interaction between the pantograph and the catenary is ensured. This implies the need for developing mathematical models of pantographs and catenaries and determining their parameters. The article presents a method to determine parameters of mechanical joints of a railway pantograph based on analysis of pantograph subassemblies in swinging motion. The...
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THE PHASE SHIFTERS INFLUENCE ON THE POWER SYSTEM STABILITY
PublikacjaThe paper presents the effect of phase shifters as FACTS devices on the possibility of improving the angle stability. Presented results obtained by the dynamic simulation performed on the mathematical model of the three machine system cooperating with the 400 kV network. The generative blocks models include turbine models with their controllers and models of synchronous generators with their excitation systems and voltage regulation....
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Five-phase squirrel-cage motor. Construction and drive properties
PublikacjaThis paper presents the simulation and experimental results of a five-phase squirrel-cage induction motor. The new machine has been designed to operate in a drive system with third harmonic rotor flux injection in order to improve the motor torque utilization. The motor structure, the mathematical model as well as the laboratory prototype have been described. The motor speed-torque characteristics and transients are elaborated...
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Kompleksowa analiza symulacyjna układu napędowego zespołu trakcyjnego
PublikacjaThe paper describes an approach to comprehensive analysis of traction electric drive. The drivetrain of ED-74 electric unit equipped with four inverter-fed induction motors was modeled in Matlab/Simulink. The model consists of functional blocks as: motors, inverters, drive controllers, filters. Structure and operation of the model was described. Chosen simulation results were presented and discussed. Two methods of modeling the...
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Semi-definite programming and quantum information
PublikacjaThis paper presents a comprehensive exploration of semi-definite programming (SDP) techniques within the context of quantum information. It examines the mathematical foundations of convex optimization, duality, and SDP formulations, providing a solid theoretical framework for addressing optimization challenges in quantum systems. By leveraging these tools, researchers and practitioners can characterize classical and quantum correlations,...
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Cross-Platform Real-Time Nuclear Reactor Basic Principle Simulator
PublikacjaAbstract—In the paper several approaches to building the real-time basic principle simulators of nuclear reactor processes are presented and their characteristics are analyzed. The characteristics of developed simulators for MATLAB/Simulink including their limitations, and the idea of a cross-platform simulator independent of specific hardware or software are presented. Mathematical models of selected nuclear reactor’s processes...
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A New Fuzzy Sliding Mode Controller with PID Sliding Surface for Underwater Manipulators
PublikacjaDesign of an accurate and robust controller is challenging topic in underwater manipulator control. This is due to hydrodynamic disturbances in underwater environment. In this paper a sliding mode control (SMC) included a PID sliding surface and fuzzy tunable gain is designed. In this proposed controller robustness property of SMC and fast response of PID are incorporated with fuzzy rules to reduce error tracking. In the control...
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A Perspective on Fast-SPICE Simulation Technology
PublikacjaThis chapter presents an introduction to the area of accelerated transistor-level (‘fast-SPICE’) simulation for automated verification and characterization of integrated circuits (ICs) from technologist’s perspective. It starts with outlining goals, expectations and typical usage models for fast-SPICE simulators, stressing how they differ from regular SPICE tools. It continues with presenting and classifying core technologies typically...
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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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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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SERVICE ORIENTED SCENARIOS FOR SUPPORT ENTERPRISE PROJECT MANAGEMENT
PublikacjaIn the paper, a service oriented architecture is used to describe various scenarios of human-oriented enterprises. They can be modeled by BPMN to show basic information flow. We consider business scenarios to present another modeling solution called service orchestration or service mashup. That approach gives an opportunity for the right management through taking the best possible choice of services, or composition of services....
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GROUP COMPOSER - System for Modeling Agents’ Team Building for Tasks
PublikacjaMulti-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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New concept and analysis of the multicell piezoelectric motor
PublikacjaThis work presents the design, modeling and tests of the prototype multicell piezoelectric motor (MPM). A new concept of the electromechanical structure of the considered prototype is based on three rotating-mode actuators. The electromechanical structure of each actuator has been considered as an independent one - referred to as a ”single cell” (single actuator). Combined three resonant actuators generate three traveling waves...