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Search results for: finite elements method
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Prediction of metal deformation due to line heating; an alternative method of mechanical bending, based on artificial neural network approach
PublicationLine heating is one of the alternative methods of forming metals and this kind of forming uses the heating torch as a source of heat input. During the process, many parameters are considered like the size of the substrate, thickness, cooling method, source power intensity, the travel speed of the power source, the sequence of heating, and so on. It is important to analyze the factors affecting the...
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Reliability-Based Stability Analysis of a Baltic Cliff by the Combined Response Surface Method
PublicationA simple, straightforward computational procedure was proposed, incorporating the Response Surface Method (RSM) linked with the standard Monte Carlo (MC) simulation method and the Point Estimate Method (PEM). PEM samples make it possible to analyse the sensitivity of the cliff’s stability to variation in subsoil parameters and to reduce the number of random variables of the problem. The proposed methods were tested in two cases:...
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A Method of Real-Time Non-uniform Speech Stretching
PublicationDeveloped method of real-time non-uniform speech stretching is presented.The proposed solution is based on the well-known SOLA algorithm(Synchronous Overlap and Add). Non-uniform time-scale modification isachieved by the adjustment of time scaling factor values in accordance with thesignal content. Dependently on the speech unit (vowels/consonants), instantaneousrate of speech (ROS), and speech signal presence, values of the scalingfactor...
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Using the Fingerprinting Method to Customize RTLS Based on the AoA Ranging Technique
PublicationReal-time Locating Systems (RTLSs) have the ability to precisely locate the position of things and people in real time. They are needed for security and emergency applications, but also for healthcare and home care appliances. The research aims for developing an analytical method to customize RTLSs, in order to improve localization performance in terms of precision. The proposed method is based on Angle of Arrival (AoA), a ranging...
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METHOD OF TRAINING THE ENDOSCOPIC VIDEO ANALYSIS ALGORITHMS TO MAXIMIZE BOTH ACCURACY AND STABILITY
PublicationIn the article a new training and testing method of endoscopic video analysis algorithms is presented. Classical methods take into account only eciency of recognizing objects on single video frames. Proposed method additionally considers stability of classiers output for real video input. The method is simple and can be trained on data sets created for other solutions. Therefore, it is easily applicable to existing endoscopic video...
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Research on Temporal Leachability of Trace Elements from Opoka-Rocks in The Aspect of Geochemical Environmental Indicators
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Structure of high-resolution Kβ1,3 x-ray emission spectra for the elements from Ca to Ge
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Experimental and numerical simulations of flow and heat transfer in heatexchanger elements using liquid crystal thermography.
PublicationPrzedstawienie koncepcji badań eksperymentalnych i numerycznych oraz ich wyników podczas wymiany ciepła w modelach klasycznych i płytowych wymienników ciepła w warunków przepływów przejściowych i turbulentnych.
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Fatigue ''safe-life'' criterion for metal elements under multiaxial static and dynamic random loads.
PublicationRozpatrywane jest stacjonarne naprężenie, którego kartezjańskie składowe są zadane w postaci sumy losowej wartości średniej i procesu stochastycznego o znanych charakterystykach probabilistycznych. Dla uwzględnienia naprężenia średniego wykorzystano uogólnioną formułę Soderberga dla materiałów ciągliwych. Zdefiniowano naprężenie równoważne o okresowych (w sensie średniokwadratowym) składowych i sformułowano kryterium zmęczenia,...
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Evaluation of quality of electric power distribution network elements in order to maintain functional and technical safety
PublicationPraca dotyczy wieloatrybutowego systemu oceny elementów sieci elektroenergetycznej do celów zapewnienia jej bezpieczeństwa funkcjonalnego i technicznego. Rozważana sieć składa się z dużej liczby elementów, ocenianych jakościowo i ilościowo. Zaproponowana metoda składa się z dwóch etapów: (i)wstępnego wyboru niewielkiej liczby elementów niebezpiecznych w oparciu o małą liczbę informacji (ii) wykonaniu uszeregowania wybranych elementów...
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Experimental study on earthquake-induced pounding between structural elements made of different building materials
PublicationCelem artykułu jest pokazanie wyników dwóch eksperymentów dotyczących zderzeń pomiędzy elementami wykonanymi z różnych materiałów budowlanych, takich jak: stal, beton, drewno i ceramika. Pierwszy z nich polegał na zrzucaniu kul na płaską powierzchnię, drugi dotyczył zderzeń modeli konstrukcji poddanych wymuszeniom sejsmicznym na stole wstrząsowym. Wyniki testów pokazują, iż wpływ materiału elementów kolidujących ze sobą na zachowanie...
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Binary Grating of Subwavelength Silver and Quantum Wires as a Photonic-Plasmonic Lasing Platform With Nanoscale Elements
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Determination of PAHs, PCBs, minerals, trace elements and fatty acids in Rapana thomasiana as an indication of pollution
PublicationW trakcie badań wykorzystano różne metodyki analityczne do oznaczania zawartości szerokiego spektrum składników (anality z grupy WWA i PCB), metali ciężkich i innych pierwiastków oraz kwasów tłuszczowych w próbkach tkanek miękkich mięczaków morskich pochodzących z miejsc o różnym poziomie antropopresji (obszary zanieczyszczone i niezanieczyszczone w bułgarskiej strefie przybrzeżnej Morza Czarnego).Analiza statystyczna uzyskanych...
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Serum trace elements in animal models and human depression: Part III. Magnesium. Relationship with copper
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Analysis of strain localization in reinforced concrete elements with explicit second-gradient strain damage approach
PublicationArtykuł omawia obliczanie elementów żelbetowych przy zastosowaniu modelu zniszczeniowego z degradacją sztywności z uwzględnieniem lokalizacji odkształceń. Obliczenia wykonano dla belek żelbetowych.
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ADOPTED ISOCHRONE METHOD IMPROVING SHIP SAFETY IN WEATHER ROUTING WITH EVOLUTIONARY APPROACH
PublicationThe paper is focused on adaptation of an isochrone method necessary for application to a weather routing system with evolutionary approach. Authors propose an adaptation of the isochrone method with area partitioning assuring that the route found by the adopted method would not cross land. In result, when applied to a weather routing system with evolutionary approach, this proposal facilitates creation of initial population, resulting...
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Proton Conducting Ceramic Powder Synthesis by a Low Temperature Method
PublicationMolten salt synthesis (MSS) is a simple method for the preparation of ceramic powders with specific morphology. The main role of the molten salts is to increase the reaction rate and lower the reaction temperature. It occurs because of much higher mobility of reactants in the liquid medium than in the solid state. In this work the molten salt synthesis was applied to produce ceramic powders of La0995Ca0005NbO4 and BaCe09−xZrxY01O3....
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Method for Assessing Rail Transport Competitiveness in Poland and the United Kingdom
PublicationBoth in Poland and United Kingdom, as well as worldwide, railways have to compete with other modes of transport, and the rail industry seeks for possibilities of achieving a competitive advantage over them. Thus, there is a need for methods for assessment of rail transport competitiveness and detection of areas for improvement. This paper presents a method developed for the Polish regional transport market and verified according...
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Method of lines for nonlinear first order partial functional differential equations.
PublicationClassical solutions of initial problems for nonlinear functional differential equations of Hamilton--Jacobi type are approximated by solutions of associated differential difference systems. A method of quasilinearization is adopted. Sufficient conditions for the convergence of the method of lines and error estimates for approximate solutions are given. Nonlinear estimates of the Perron type with respect to functional variables...
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Adaptive Multiplex Resource Allocation Method for DAB+ Broadcast System
PublicationIn this paper an adaptive multiplex resource allocation method for the DAB+ broadcast system is presented. An analysis of content transmitted over different radio programs with respect to their profile is discussed. Simulation results of an adaptive multiplexer, as well as the technological demonstrator, fully compatible with the DAB+ standard, are described. The concept is verified by a subjective quality assessment study of real-time...
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Method of estimating the rolling resistance coefficient of vehicle tyre using the roller dynamometer
PublicationThe tendency in the past few years has been to introduce tyres with lower rolling resistance coefficients to the market. This paper presents a mathematical method for determining the rolling resistance coefficients variation depending on the speed. The method uses power balance which results from automobile dynamics while rolling on chassis dynamometer. The rolling resistance coefficients of tyres obtained through ‘drum test method’,...
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The new investing effectiveness evaluation multi-criteria method in modern supply systems
PublicationThe important problem in the processes of modelling and programming the development of sustainable energy sector is the multi-criteria manner of assessing the effectiveness of investments. The goal of this paper is to show how to take into account the impact of investments in multidimensional modelling decision-making processes. This goal can be achieved through the development, presentation, and use of a new multi-criteria method...
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Use of the AHP Method for Preference Determination in Yacht Design
PublicationA sailing yacht is a human-centred product, the design of which revolves primarily around the wants and desires of the future owner. In most cases, these preferences are not measurable, such as a personal aesthetic feeling, or a need for comfort, speed, safety etc. The aims of this paper are to demonstrate that these preferences can be classified and represented numerically, and to show that they are correlated with the type of...
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Use of the AHP Method for Preference Determination in Yacht Design
PublicationA sailing yacht is a human-centred product, the design of which revolves primarily around the wants and desires of the future owner. In most cases, these preferences are not measurable, such as a personal aesthetic feeling, or a need for comfort, speed, safety etc. The aims of this paper are to demonstrate that these preferences can be classified and represented numerically, and to show that they are correlated with the type...
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Simplified method of water cooled exhaust system design.
PublicationThe water cooled exhaust systems are not often used onboard ships. Prime goal is to lower temperature of exhaust gas from main propulsion and auxiliary engines to the defined limit. The design of such systems require detailed analysis of propulsion system operational parameters to meet designer expectations. The paper outlines the cooled exhaust system design problems in specific application. The simplified method of evaluation...
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Interior Point Method Evaluation for Reactive Power Flow Optimization in the Power System
PublicationThe paper verifies the performance of an interior point method in reactive power flow optimization in the power system. The study was conducted on a 28 node CIGRE system, using the interior point method optimization procedures implemented in Power Factory software.
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Validation of Hydraulic Mechanism during Blowout Trauma of Human Orbit Depending on the Method of Load Application
PublicationThe more we know about mechanisms of the human orbital blowout type of trauma, the better we will be able to prevent them in the future. As long as the buckling mechanism’s veracity is not in doubt, the hydraulic mechanism is not based on equally strong premises. To investigate the correctness of the hydraulic mechanism’s theory, two different methods of implementation of the hydraulic load to the finite element method (FEM) model...
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Reliability assessment of truss towers using Monte Carlo Method, PEM and RSM
PublicationThe paper discusses reliability assessment of simple random truss structures using three different probabilistic methodologies: the Monte Carlo Method (MCM), the Point Estimate Method (PEM) and the Response Surface Method (RSM). A benchmark truss structure and a simplified full–size engineering tower are both analyzed. A set of ultimate load numerical calculations is performed and the results are taken as the basis of advanced...
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A Method for Underwater Wireless Data Transmission in a Hydroacoustic Channel under NLOS Conditions
PublicationWireless data transmission in the hydroacoustic channel under non-line-of-sight (NLOS) propagation conditions, for example, during a wreck penetration, is difficult to implement reliably. This is mostly due to the multipath propagation, which causes a reduction in the quality of data reception. Therefore, in this work an attempt has been made to develop a reliable method of wireless underwater communication test it under the NLOS...
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A Generalized SDP Multi-Objective Optimization Method for EM-Based Microwave Device Design
PublicationIn this article, a generalized sequential domain patching (GSDP) method for efficient multi-objective optimization based on electromagnetics (EM) simulation is proposed. The GSDP method allowing fast searching for Pareto fronts for two and three objectives is elaborated in detail in this paper. The GSDP method is compared with the NSGA-II method using multi-objective problems in the DTLZ series, and the results show the GSDP method...
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Investigations of size effect in concrete at aggregate level - experiments and calculations results using discrete element method
PublicationSize effect is a fundamental phenomenon in concrete. It is characterised by decreasing strength and increasing brittleness of concrete with increasing size. The thesis includes experimental and theoretical elements. The main goal of the thesis were investigations of a size effect at the aggregate level by taking fracture into account with the discrete element method (DEM) for various failure modes. Comprehensive experiments on...
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AgileSafe – a method of introducing agile practices into safety-critical software development processes
PublicationThis article introduces AgileSafe, a new method of incorporating agile practices into critical software development while still maintaining compliance with the software assurance requirements imposed by the application domain. We present the description of the method covering the process of its application and the input and output artefacts.
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Discrete Green's function approach to disjoint domain simulations in 3D FDTD method
PublicationA discrete Green’s function (DGF) approach to couple 3D FDTD subdomains is developed. The total-field/scattered-field subdomains are simulated using the explicit FDTD method whilst interaction between them is computed as a convolution of the DGF with equivalent current sources measured over Huygens surfaces. In the developed method, the DGF waveforms are truncated using the Hann’s window. The error varies in the range -65 to -40...
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A new diagnostic method for evaluation of cardiosurgery wound healing
PublicationOne of important and still unsolved problems in medicine is the question of objective and quantitative evaluation of post-surgery wound healing. The aim of this research is to analyse possibility and value of using the newly elaborated infrared imaging procedure – Active Dynamic Thermography (ADT) – for quantitative description of wound healing processes in cardiosurgery. Both, classical thermal figures of merit as well as ADT...
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Polynomial description of dynamic impedance spectrogram—introduction to a new impedance analysis method
PublicationThis paper presents a polynomial description of spectrograms obtained using Dynamic Electrochemical Impedance Spectroscopy. A method to fit the polynomial degree correctly is discussed. A simple electrical system of a diode connected in parallel with a capacitor was used for testing. Dynamic impedance measurements during potentiodynamic polarization were conducted. This paper presents an alternative analysis method that allows...
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Method of Decision-Making Logic Discovery in the Business Process Textual Data
PublicationGrowing amount of complexity and enterprise data creates a need for novel business process (BP) analysis methods to assess the process optimization opportunities. This paper proposes a method of BP analysis while extracting the knowledge about Decision-Making Logic (DML) in a form of taxonomy. In this taxonomy, researchers consider the routine, semi-cognitive and cognitive DML levels as functions of BP conceptual aspects of Resources,...
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Improvement of Fingerprinting Method based on Hill Cipher by using Frequency Domain
PublicationThe main goal of this paper is to present the advantages of a digital fingerprinting in a frequency domain over a pixel domain, in case of VoD services (Video on Demand). The paper presents basic issues of a multimedia data protection by digital fingerprinting. It also describes threats to embedded fingerprints from both collusion attacks and from a transmission itself. Possible solution was presented on the example of the DCT...
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On the validation of the LS-DYNA Geo Metro numerical model
PublicationThe paper presents experiences gained during work with numerical model of Geo Metro vehicle used for simulations of crash tests with road safety barriers. Attention is drawn to the subject of tire/wheel breakage during collision events. Some methods for improvement of the model are presented in the paper. Several results for the normative vehicle numerical tests are introduced. Simulations were carried out using LS-DYNA finite...
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Method of selecting programming practices for the safety-critical software development projects
PublicationIn recent years a plan-driven approach traditionally used in safety-critical software development has been put to a test by rapidly changing technologies, more diverse group of clients and volatile market requirements. The need to deliver good quality systems, faster and at lower cost in comparison to competitors encouraged companies to look for more efficient solutions. Agile methodologies are known to successfully address these...
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A Novel Bitrate Adaptation Method for Heterogeneous Wireless Body Area Networks
PublicationIn the article, a novel bitrate adaptation method for data streams allocation in heterogeneous Wireless Body Area Networks (WBANs) is presented. The efficiency of the proposed algorithm was compared with other known algorithms of data stream allocation using computer simulation. A dedicated simulator has been developed using results of measurements in the real environment. The usage of the proposed adaptive data streams allocation...
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Reliability Analysis of Sea Cliff Slope Stability by Point Estimate Method
PublicationThe paper presents a reliability analysis of a sea cliff slope. The cliff, located in Jastrzębia Góra, is characterised by a complicated geological structure. Although currently stable, it is in fact close to the limit state. The objective of this paper is to present the point estimate method (PEM) of determining the mean value and standard deviation of the safety factor of the slope. Assuming its normal distribution, these statistical...
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A Novel Bitrate Adaptation Method for Heterogeneous Wireless Body Area Networks
PublicationIn the article, a novel bitrate adaptation method for data streams allocation in heterogeneous Wireless Body Area Networks (WBANs) is presented. The efficiency of the proposed algorithm was compared with other known algorithms of data stream allocation using computer simulation. A dedicated simulator has been developed using results of measurements in the real environment. The usage of the proposed adaptive data streams allocation...
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Reliability Analysis of Sea Cliff Slope Stability by Point Estimate Method
PublicationThe paper presents a reliability analysis of a sea cliff slope. The cliff, located in Jastrzębia Góra, is characterised by a complicated geological structure. Although currently stable, it is in fact close to the limit state. The objective of this paper is to present the point estimate method (PEM) of determining the mean value and standard deviation of the safety factor of the slope. Assuming its normal distribution, these statistical...
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Parallelization Method for a Continuous Property
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A dressing method in mathematical physics
PublicationMetodę ubierania stosuje się do równań nieliniowych całkowalnych i w teorii potencjałów całkowalnych mechaniki kwantowej.
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A method of RTS noise identification in noise signals of semiconductor devices in the time domain
PublicationIn the paper a new method of Random Telegraph Signal (RTS) noise identification is presented. The method is based on a standardized histogram of instantaneous noise values and processing by Gram-Charlier series. To find a device generating RTS noise by the presented method one should count the number of significant coefficients of the Gram-Charlier series. This would allow to recognize the type of noise. There is always one (first)...
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Detection of the First Component of the Received LTE Signal in the OTDoA Method
PublicationIn a modern world there is a growing demand for localization services of various kinds. Position estimation can be realized via cellular networks, especially in the currently widely deployed LTE (Long Term Evolution) networks. However, it is not an easy task in harsh propagation conditions which often occur in dense urban environments. Recently, time-methods of terminal localization within the network have been the focus of attention,...
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EXPERIMENTAL AND NUMERICAL VALIDATION OF THE IMPROVED VORTEX METHOD APPLIED TO CP745 MARINE PROPELLER MODEL
PublicationThe article presents a numerical analysis of the CP745 marine propeller model by means of the improved vortex method and CFD simulations. Both numerical approaches are validated experimentally by comparing with open water characteristics of the propeller. The introduced modification of the vortex method couples the lifting surface approach for the propeller blades and the boundary element method for the hub. What is more, a...
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DiSTFAG method robust to gross errors in monitoring displacements and strains in unstable reference systems
PublicationThe DiSTFA method (Displacements and Strains using Transformation and Free Adjustment) was presented in Kamiński (2009). The method has been developed for the determination of displacements and strains of engineering objects in unstable reference systems, as well as for examining the stability of reference points. The DiSTFAG (Gross errors) method presented in the paper is the extension of the DiSTFA method making it robust to...
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Proposal of a method for effective tasks distribution in the execution of compolex problems
PublicationAn access to a great number of various services allows for decomposition of complex problems into smaller and less complex tasks. Those tasks can be presented in a form of a dependency graph. This paper shows an idea of executing such a problem using cooperating autonomous agents. Main focus of this work is cooperation covering effective tasks distribution among executors. This paper presents an algorithm for dynamic executor selection...