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Search results for: APPROXIMATION THEORY , INTERPOLATION , MONOPOLE ANTENNAS , PARETO OPTIMISATION , STATISTICAL ANALYSIS , ULTRA WIDEBAND ANTENNAS
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Geometrically Nonlinear Analysis of Functionally Graded Shells Based on 2-D Cosserat Constitutive Model
PublicationIn this paper geometrically nonlinear analysis of functionally graded shells in 6-parameter shell theory is presented. It is assumed that the shell consists of two constituents: ceramic and metal. The mechanical properties are graded through the thickness and are described by power law distribution. Formulation based on 2-D Cosserat constitutive model is used to derive constitutive relation for functionally graded shells. Numerical...
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Interface analysis of compatibilized polymer blends
PublicationThis chapter seeks to address the interface location in the compatibilized polymer blends and paves the way for quantitative analysis of interface in terms of interfacial tension and interfacial adhesion to provide support for understanding the relationship between morphology and ultimate properties in the compatibilized polymer blends through the lens of interface. Since understanding and analysis of interfacial phenomena in the...
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Security aspects in functional safety analysis
PublicationA security level of distributed control and protection system may have a significant impact on the results of functional safety analysis. However, the issue of integrating the safety and security aspects is difficult and usually is neglected during the functional safety analysis. This article presents a method of functional safety analysis which takes into consideration a concept of integrating these two aspects. It is based on...
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On analysis of nanocomposite conical structures
PublicationThis research examines the analysis of rotating truncated conical baskets reinforced by carbon nanotubes around the two independent axes. A time-dependent analysis is considered, and the nonlinear dynamic governing equations are extracted using the energy method. Carbon nanotubes (CNTs) reinforced the conical basket, and the structure's mechanical properties are determined based on the several distributions of carbon nanotubes....
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WORK MOTIVATION PROFILES AND WORK PERFORMANCE IN A GROUP OF CORPORATE EMPLOYEES: A TWO-STEP CLUSTER ANALYSIS
PublicationFew studies have applied a person-centered approach to work motivation using cluster or profile analyses. Thus, little is known about which configurations of work motivations characterize professionals. The aim of this study is to establish the structure of work motivation profiles under the framework of self-determination theory and to examine the relationship between work motivation and subjective work performance. The study...
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Customized crossover in evolutionary sets of safe ship trajectories
PublicationThe paper presents selected aspects of evolutionary sets of safe ship trajectories-a method which applies evolutionary algorithms and some of the assumptions of game theory to solving ship encounter situations. For given positions and motion parameters of the ships, the method finds a near optimal set of safe trajectories of all ships involved in an encounter. The method works in real time and the solutions must be returned within...
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Video Semantic Analysis Framework based on Run-time Production Rules - Towards Cognitive Vision
PublicationThis paper proposes a service-oriented architecture for video analysis which separates object detection from event recognition. Our aim is to introduce new tools to be considered in the pathway towards Cognitive Vision as a support for classical Computer Vision techniques that have been broadly used by the scientific community. In the article, we particularly focus in solving some of the reported scalability issues found in current...
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Kriging metamodels and design re‐utilization for fast parameter tuning of antenna structures
PublicationThe paper addresses the problem of computationally efficient electromagnetic (EM)‐driven design closure of antenna structures. The foundations of the presented approach are fast kriging interpolation metamodels, utilized for two purposes: (a) producing a good starting point for further parameter tuning, and (b) yielding a reasonable Jacobian matrix estimate to jump‐start the optimization procedure. The models are rendered using...
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A Mesh Deformation Technique Based on Solid Mechanics for Parametric Analysis of High-Frequency Devices With 3-D FEM
PublicationIn this paper, a versatile technique for mesh defor- mation is discussed, targeted at the electromagnetic (EM) field simulation of high-frequency devices using the 3-D finite element method (FEM). The approach proposed applies a linear elasticity model to compute the displacements of the internal mesh nodes in 3-D when the structure geometry is changed. The technique is compared with an alternative approach...
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Analysis of aircraft magnetic interference
PublicationThe magnetometric method is used among other things on mobile platforms (planes, helicopters) in military systems and in geological research. Optically-pumped and SQUID magnetometers are used in magnetic systems on airplanes. To be able to attain the sensitivity of modern magnetometers in flight, it is important that maneuver-related magnetic interference effects be minimized. The mathematical model of an aircraft as a source of...
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Analysis of aircraft magnetic interference
PublicationThe magnetometric method is used among other things on mobile platforms (planes, helicopters) in military systems and in geological research. Optically-pumped and SQUID magnetometers are used in magnetic systems on airplanes. To be able to attain the sensitivity of modern magnetometers in flight, it is important that maneuver-related magnetic interference effects be minimized. The mathematical model of an aircraft as a source of...
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Analysis of Reasons of Accidents Between Cyclists and Public Transport Vehicles in Cities
PublicationIn European cities, a bicycle is now or is systematically becoming an equal means of transport. Unfortunately, the growth of bicycle traffic is associated with an increase in the number of accidents involving cyclists. Some of these accidents, are events with cyclists and public transport vehicles - and therefore means of transport, which together are to constitute a serious alternative to a car. Although the share of these kind...
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Particulate Material Analysis in Air
PublicationThe chapter presents the methods and techniques used to asses the PM10 in air and different instruments typically used in analysis of PM, including sampling of particle by using filters and other systems. Besides the methods recommended by different national standards the other methods, especially electronic microscopy are also described.
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APPLICATION OF THE THEORY OF SEMI-MARKOV PROCESSES TO DETERMINE A LIMITING DISTRIBUTION OF THE PROCESS OF CHANGES OF ABILITY AND INABILITY STATES OF FUEL SUPPLY SYSTEMS IN HEAVY FUEL DIESEL ENGINES
PublicationThe paper presents applicability of the theory of semi-Markov processes to determine a limiting distribution of the process of changes of technical states of fuel systems for marine engines running on heavy fuel oils. The proposed study of this process includes the components of such fuel systems like: 1 - injectors, 2 - high pressure hoses, 3 - injection pumps, 4 - low pressure hoses, 5 – fine filters, 6 - coarse filters, 7 – fuel-feed...
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Correlation between Fractal Dimension and Areal Surface Parameters for Fracture Analysis after Bending-Torsion Fatigue
PublicationThis paper investigates the fracture surface topography of two steel and aluminum alloys subject to bending-torsion fatigue loadings, as well as their susceptibility to fatigue performance and failure mechanisms. Using fracture surface topography data analysis, elements with different geometries were elaborated. A correlation between the fractal dimension, other selected parameters of surface topography such as areal Sx, and...
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Analysis of leakage flux in deenergized transformer
PublicationThe article presents the numerical analysis of the magnetic field that occurs around the transformer after it has been switched off. The purpose of this analysis was to determine if it is possible to define the residual fluxes in the legs of transformer based on the measurements of this field. These studies have allowed us to determine the quantity and location of the sensors. The influence of the Earth's magnetic field has also...
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Assessment of User Mobility’s Influence on System Loss in Several Body-to-Body Scenarios
PublicationIn this paper, Body-to-Body communications in indoor and outdoor environments for different on-body antenna configurations and different mobility scenarios were studied, based on system loss measurements at 2.45 GHz. The main objective is to properly characterise the influence of the Transmitter-Receiver configuration on system loss and fast fading behaviour, the latter being modelled by the Rice Distribution. Globally, it is observed...
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Acceleration of the DGF-FDTD method on GPU using the CUDA technology
PublicationWe present a parallel implementation of the discrete Green's function formulation of the finite-difference time-domain (DGF-FDTD) method on a graphics processing unit (GPU). The compute unified device architecture (CUDA) parallel computing platform is applied in the developed implementation. For the sake of example, arrays of Yagi-Uda antennas were simulated with the use of DGF-FDTD on GPU. The efficiency of parallel computations...
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Analysis of Signalized Intersections in the Context of Pedestrian Traffic
PublicationGdynia is a city in the Pomeranian Voivod e ship of Poland with a population of about 250,000. It faces a growing motorization rate th at needs to be addressed. Car ownership in Gdynia now exceed s 500 vehicles per 1000 residents. Travel by public transport is decreasing and the rate of walking and cycling remains low. It is necessary to reverse these negative trends by implementing solu tions based...
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Green adsorbents and solvents in food analysis
PublicationGreen analytical chemistry aims to minimize the negative impact of analytical procedures on the environment and human health. This can be achieved through the use of non-toxic and environmentally friendly reagents. Classical green solvents include water, ethanol, acetone, and supercritical fluids. Water has been used for the extraction of water-soluble compounds (sugars, amino acids). Ethanol and acetone have been used for the...
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Evaluation of possibilities of genotyping of Candida glabrata clinical isolates with RAPD-PCR method and microsatellite analysis
PublicationThe aim of the study was to compare the discriminatory power of RAPD-PCR method using RSD10 primer and microsatellite (GACA)4 analysis for genotyping clinical isolates of C. glabrata. Isolates were received from patients of two Polish hospitals: Children's Memorial Health Institute in Warsaw (n=17) and Medical University of Gdansk (n=37). Species identification was confirmed by two phenotypic methods: growth on chromagar plates...
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Practical Approach to Large-Scale Electronic Structure Calculations in Electrolyte Solutions via Continuum-Embedded Linear-Scaling Density Functional Theory
PublicationWe present the implementation of a hybrid continuum-atomistic model for including the effects of a surrounding electrolyte in large-scale density functional theory (DFT) calculations within the Order-N Electronic Total Energy Package (ONETEP) linear-scaling DFT code, which allows the simulation of large complex systems such as electrochemical interfaces. The model represents the electrolyte ions as a scalar field and the solvent...
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Physics-guided neural networks (PGNNs) to solve differential equations for spatial analysis
PublicationNumerous examples of physically unjustified neural networks, despite satisfactory performance, generate contradictions with logic and lead to many inaccuracies in the final applications. One of the methods to justify the typical black-box model already at the training stage and lead to many inaccuracies in the final applications. One of the methods to justify the typical black-box model already at the training stage involves extending...
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Circularly Polarized Metalens Antenna Design for 5G NR Sub-6 GHz Communication Systems
Publication5G NR (new radio) FR1 range refers to as Sub-6GHz band (410MHz to 7125MHz and 3.4GHz to 6GHz). In this paper, the frequency range of interest is from 3.4 to 6GHz, as many cellular companies are focusing on this Sub-6GHz band. A wideband circularly polarized (CP) antenna radiator is designed with diamond shape patches, fed by a microstrip line at the bottom through a rectangular shape wide slot on a ground plane. The proposed CP...
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Numerical analysis of a temporary steel grandstand
PublicationThe purpose of this paper is to present the results of the numerical analysis focused on the response of the temporary steel scaffolding grandstand subjected to human-induced vibrations due to jumping. Shell as well as beam elements have been used in the numerical model. Its first stage has involved conducting modal analysis in order to determine the modes of free vibrations and the corresponding natural frequencies for the empty...
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Improved Efficacy Behavioral Modeling of Microwave Circuits through Dimensionality Reduction and Fast Global Sensitivity Analysis
PublicationBehavioral models have garnered significant interest in the realm of high-frequency electronics. Their primary function is to substitute costly computational tools, notably electromagnetic (EM) analysis, for repetitive evaluations of the structure under consideration. These evaluations are often necessary for tasks like parameter tuning, statistical analysis, or multi-criterial design. However, constructing reliable surrogate models...
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Fractal analysis of the bending-torsion fatigue fracture of aluminium alloy
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Multimodal Genetic Algorithm with Phase Analysis to Solve Complex Equations of Electromagnetic Analysis
PublicationIn this contribution, a new genetic-algorithm-based method of finding roots and poles of a complex function of a complex variable is presented. The algorithm employs the phase analysis of the function to explore the complex plane with the use of the genetic algorithm. Hence, the candidate regions of root and pole occurrences are selected and verified with the use of discrete Cauchy's argument principle. The algorithm is evaluated...
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Contour Analysis of Bleeding Regions in Endoscopic Images
PublicationThis paper investigates the problem of detecting bleeding regions in images acquired from endoscopic examinations of gastrointestinal tract. The purpose is to identify the characteristic features of bleeding areas' contours in order to develop an accurate method for discriminating between true bleeding regions and missed detections, which could lead to a significant reduction of the false alarm rate of existing blood-detection...
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The Analysis of Vodka: A Review Paper
PublicationVodka is the most popular alcoholic beverage in Poland, Russia and other Eastern European countries, made from ethyl alcohol of agricultural origin that has been produced via fermentation of potatoes, grains or other agricultural products. Despite distillation and multiple filtering, it is not possible to produce 100 % ethanol. The solution with a minimum ethanol content of 96 %, which is used to produce vodkas, also contains trace amounts...
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Hydrophobic PVDF hollow fiber membranes with narrow pore size distribution and ultra-thin skin for the fresh water production through membrane distillation
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Sensitivity analysis of free torsional vibration frequencies of thin-walled laminated beams under axial load
PublicationThe paper addresses sensitivity analysis of free torsional vibration frequencies of thin-walled beams of bisymmetric open cross-section made of unidirectional fibre-reinforced laminate. The warping effect and the axial end load are taken into account. The consideration is based upon the classical theory of thin-walled beams of non-deformable cross-section. The first-order sensitivity variation of the frequencies is derived with...
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Optimisation of pressurised liquid extraction for elimination of sulphur interferences during determination of organotin compounds in sulphur-rich sediments by gas chromatography with flame photometric detection
PublicationOpracowano metodę analizy osadów dennych na zawartość związków cynoorganicznych (MBT, DBT, TBT, MPhT, DPhT, TPhT) przy użyciu przyspieszonej ekstrakcji rozpuszczalnikiem i chromatografii gazowej z detektorem płomieniowo-fotometrycznym. Detektor ten pozwala selektywnie wykrywać niewielkie ilości pochodnych cynoorganicznych. Niestety, bardzo często spotykana w osadach siarka oraz jej pochodne zakłócają sygnał detektora. Z tego względu...
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Design and optimisation of combinational digital circuits using modified evolutionary algorithm.Projektowanie i optymalizacja kombinacyjnych układów cyfrowych przy użyciu zmodyfikowanego algorytmu ewolucyjnego.
PublicationW pracy przedstawiono możliwości projektowania i optymalizacji układów kombinacyjnych przy użyciu zmodyfikowanych algorytmów ewolucyjnych. Modyfikacja algorytmów polega na wprowadzeniu chromosomów wielowarstwowych i operatorów działających na nich. Wyniki projektowania czterech układów kombinacyjnych uzyskanych uzyskane tą metodą porównano z następującymi metodami opisanymi w literaturze jak: Mapy Karnaugh, metoda Quine-McCluskey...
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On the use of enhanced strain formulation in 6-field nonlinear shell theory with asymetric strain measures
PublicationW pracy zbadano możliwość zastosowania techniki wzbogaconych odkształceń do usunięcia zjawiska blokady w elementach skończonych opracowanych w ramach 6-parametrowej nieliniowej teorii powłok z niesymetrycznymi miarami odkształceń membranowych. Przedstawiono i porównano 4 warianty pol wzogacających odkształcenia
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Experimental evidence about misconception of Terzaghi's 1-D consolidation theory in terms of degree of consolidation
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Adsorption of a metalorganic complex at a metal surface: A density functional theory study vs. model description
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Relationships between work ethic and motivation to work from the point of view of the self-determination theory
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Application of an extended DLVO theory for the calculation of the interactions between emulsified oil droplets in alcohol solutions
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Synthesis and Comprehensive Structural and Chiroptical Characterization of Enones Derived from (−)-α-Santonin by Experiment and Theory
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Study of passive deck-flaps flutter control system on full bridge model. I: Theory
PublicationSformułowano modele matematyczne drgań mostu z zamontowanym pasywnym systemem sterowania flatterem w formalizmie metody elementów skończonych. System wykorzystuje stateczniki dołączone bezpośrednio do przęsła mostu. Siły aerodynamiczne działające bezpośrednio na most i stateczniki sformułowane są w przestrzeni czasu.
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On the theory and numerical simulation of acoustic and heat modes interaction in a liquid with bubbles: acoustic quasi-solitons
PublicationTeoria rzutowania zaburzenia ogólnego na mody. Zastosowanie metody do badań układu równań typu Korteweg`a-de Vries`a. Rozwiązania analityczne i simulacje numeryczne.
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Modulation of dielectric properties in low-loss polypropylene-based composites at GHz frequencies: theory and experiment
PublicationPolymer composites with high dielectric constant and low loss tangent are highly regarded as substrates for modern high-speed electronics. In this work, we analyze the high-frequency dielectric properties of two types of composites based on polypropylene infused with high-dielectric-constant microparticles. Two types of fillers are used: commercial ceramics or titanium oxide ( TiO2) with different concentrations. The key observation...
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Multiple solutions of indefinite elliptic systems via a Galerkin-type Con- ley index theory
PublicationW pracy wykazano prawdziwość hipotezy Angenenta i van der Vorsta dotyczącąilości rozwiązań pewnego układu eliptycznego. Liczbę rozwiazań szacuje się zdołu przy pomocy niezmiennika topologicznego zwanego uogólnionym indeksemMorse`a. W dowodzie stosuje sie niezmienniczy index Conleya w przestrzeniachHilberta.
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Numerical analysis of elastic wave propagation in unbounded structures
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Water uptake analysis of acceptor-doped lanthanum orthoniobates
PublicationIn this work, lanthanum orthoniobates doped with either antimony, calcium, or both have been synthesized and studied. The water uptake of the investigated materials has been analyzed by means of thermogravimetric studies. The results show the difference between the thermodynamics of hydration between the lanthanum orthoniobate system and other proton conducting ceramics. The relation between the water uptake and effective acceptor...
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Spectral Analysis of Capital Markets
PublicationIn this paper the problem of cycles existence in capital markets is addressed. A spectral analysis algorithm, which reduces signal-to-noise ratio, is proposed to derive cycle periodograms for the yield function of DJIA, WIG~20, and NIKKEI 225 indices. Peaks of the the periodograms provide premises to postulate the existence of some possible cycles. The 3.5 year periodicity in all 3 indices, which can be related to Kitchin cycle...
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UE ETS: an in-depth descriptive analysis.
PublicationThe European Emission Trading System (EU ETS) plays a pivotal role in the EU’s strategy to address climate change, serving as a fundamental instrument for cost-effective reduction of greenhouse gas emissions. Notably, it inaugurated the word’s first major carbon market and it continues to the largest one. Chapter 1 provides an in-depth examination of the EU ETS, spanning from its inception in 2005 to 2020. After providing a descriptive...
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Adapting new tools of urban freight management based on Gdynia’s dedicated delivery bays example – an analysis of the process
PublicationThe article presents an analysis of a process which ultimately helped Gdynia to designate pilot delivery sites in its downtown area using international experience. A verification was conducted of policy transfer theory and its practical implementation based on an URBACT Freight Tails project. While the choice of the solution was based on critical analysis of existing practical examples, it needed to be adapted to the local conditions...
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Agile Media Management Approach – an analysis
PublicationThis article studies media management and demonstrates a fresh perspective on the new approach based on agile methodologies of project management. The analysis sequentially presents a literature overview of media and its management, the characteristics of media projects, agile project management, an analysis of agile approaches and media management along with the proposal of a...