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Search results for: ELECTROMAGNETIC FIELD THEORY
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Moddeling urban processes based on requirements ofself-organization theory.
PublicationW artykule przedstawiono ogólne podstawy symulacji rozwoju urbanistycznego w oparciu o modele komórkowe. Nowa teoria, wykorzystująca aparat matematyczny stworzony do badań i modelowania dynamiki układów nieliniowych, rozszerza również możliwości poznawcze i wykorzystanie systemów GIS w szeroko pojmowanym planowaniu przestrzennym. Jej szybki rozwój w ostatnich latach i niezwykłe osiągnięcia w poznaniu procesów rządzących podstawową...
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Seafloor backscattering: numerical simulation vs. filter theory approach.
PublicationPrzedstawiono model opisujący rozpraszanie sygnału akustycznego na nierównomiernej, regularnie sfalowanej powierzchni dna morskiego jako filtr liniowy z odpowiedzią impulsową o zmieniającej się w czasie chwilowej dominującej częstotliwości. Porównano przewidywania modelu z wynikami otrzymanymi w wyniku złożonych obliczeniowo symulacji numerycznych opartych na fizycznym modelu zjawiska wykorzystującym aproksymację Kirchhoffa. Wstępnie...
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Thermodynamically consistent gradient theory of damage coupled with gradient plasticity
PublicationPrzedstawiono termodynamicznie zgodną teorię plastycznego zniszczenia w zakresie mechaniki Newtona-Eshelbego. Poza klasycznymi równaniami ruchu w przestrzeni fizycznej sformułowano dynamiczne równania równowagi sił powiązanych z defektami w przestrzeni materialnej oraz pierwsze i drugie prawo termodynamiki w przestrzeni fizycznej i materialnej. Ogólne równania konstytutywne przyjęto jako funkcję gradientu deformacji, jego składników...
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pH gradient high-performance liquid chromatography: theory and applications
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The Poland-United States Security Relations in the light of Asymmetry Theory
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Application of percolation theory for description of electrical properties of conducting coatings
PublicationPrzedstawiono pomiary elektryczne i elektrochemiczne powłok organicznych przewodzących prąd elektryczny i mogących pełnić rolę anody w systemie ochrony katodowej żelbetonu. Za pomocą pomiarów impedancyjnych dokonano oceny rezystancji powłoki w funkcji zawartości grafitu. Na tej podstawie oszacowano próg perkolacji powłoki epoksydowej domieszkowanej elektrografitem. Ocenę obciążalności prądowej powłok przewodzących dokonano wykonując...
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On the FEM implementation of the large rotation shell theory for elasticanisotropic shells.
PublicationW pracy przedstawiono problemy implementacji MES teorii powłok o dużych obrotach w statycznej, geometrycznie nieliniowej analizie konstrukcji warstwowych. Zwrócono uwagę na właściwą interpretacje rotacyjnych stopni swobody w algorytmie MES. Omówiono wariant dużych i skończonych obrotów. Przedstawiono wyniki obliczeń dla znanego w literaturze przykładu analizy paneli kompozytowej w zakresie dużych obrotów.
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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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On shear correction factors in the non-linear theory of elastic shells
PublicationW pracy wyprowadzono analitycznie wartości korekcyjnych współczynników ścinania dla ścinania poprzecznego oraz dla momentów owinięcia w ramach nieliniowej sześcioparametrowej teorii powłok. Wartości wyprowadzono poprzez odpowiednie sformułowanie komplementarnej energii sprężystej. Na drodze analizy przy pomocy MES, badano wpływ wartości współczynników na położenie punktów bifurkacji, deformacje, całkowitą energię sprężystą układu...
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Analysis of the objects images on the sea using Dempster-Shafer Theory
PublicationThe paper presents the concept of using aerial and satellite imagery or images coming from the marine radar to identify and track vessels at sea. The acquired data were subjected to a highly advanced image analysis. The development of remote sensing techniques allows to gain a huge amount of data. These data are useful information source however usually we have to use different data mining methods to gain interested information....
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Chemical Theory of Machines, basic principles of strength with examples of calculations
PublicationThis book encompasses the essential range of information on technical aspects of mechanical design. It was written primarily for the students and staff of chemistry faculties of technical universities, yet it may also be utilized by everyone, who ether would like to try or already enjoys designing, but cannot take advantage of typical stress & machine construction handbooks. These handbooks often require familiarity with the concepts...
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Application of Multiplexed Replica Exchange Molecular Dynamics to the UNRES Force Field: Tests with α and α+β Proteins
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Nonlocal three-dimensional theory of elasticity for buckling behavior of functionally graded porous nanoplates using volume integrals
PublicationIn this paper, the buckling of rectangular functionally graded (FG) porous nanoplates based on threedimensional elasticity is investigated. Since, similar researches have been done in two-dimensional analyses in which only large deflections with constant thickness were studied by using various plate theories; therefore, discussion of large deformations and change in thickness of plates after deflection in this study is examined....
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A Regional ITRF Densification by Blending Permanent and Campaign Data — The CEGRN campaigns and the Central European Velocity Field
PublicationThe CERGOP Project of the Central European Countries initiated six GPS observation campaigns from 1994 to 2001. By the high standards set within this project for site selection, observation and analysis a consistent set of epoch solutions with a precision in the 3–5 mm range was created. The network contains about 19 permanent and 38 epoch stations. In this paper a first combination solution over the seven years with a velocity...
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Karolina Zielińska-Dąbkowska dr inż. arch.
PeopleKarolina M. Zielinska-Dabkowska, Ph.D., Eng. Arch., M. Arch., is an Assistant Professor at the Faculty of Architecture of Gdańsk University of Technology (GUT). In 2002, she completed her studies of Architecture and Urban Planning at Gdańsk University of Technology (Gdańsk Tech) and in 2004, Architectural Engineering at the University of Applied Sciences and Arts (HAWK) in Hildesheim, Germany. After graduation, she worked for several...
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Complex modulus of Cement Bitumen Treated Material Mixture C3E4 cores obtained from the field section (28-365 days of curing at the field and later in laboratory at 20C)
Open Research DataDataset presents data of complex modulus determined for cold recycled mixture – cement bitumen treated material mixture with following binding agents: 3% cement, 4% emulsion (C3E4). Mixture was designed according to Polish requirements for the base course of pavement. Specimen were obtained from the field at 28, 180, 270 and 365 days after compaction....
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Considerations about the applicability of the Reynolds equation for analyzing high-speed near field levitation phenomena
Publicationequation for analyzing near field levitation (NFL) phenomena. Two separate approaches were developed, experimentally verified, and applied to meet the research objective. One was based on the Reynolds equation and the other was based on general conservation equations for fluid flow solved using computational fluid dynamic (CFD). Comparing the calculation results revealed that, for certain operating conditions, differences in the...
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[NF] Physical Research Methods III: Scattering Theory
e-Learning Courses{mlang pl} Dyscyplina: NF Zajęcia obowiązkowe dla doktorantów II i III roku Prowadzący: Prof. Simone Taioli Liczba godzin: 15 Forma zajęć: wykład/seminarium {mlang} {mlang en} Discipline: NF Obligatory course for 2-nd and 3-rd year PhD students Academic teacher: Prof. Simone Taioli Total hours of training: 15 teaching hours Course type: lecture/seminar {mlang}
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Low Frequency Electromagnetic Interferences Impact on Transport Security Systems Used in Wide Transport Areas
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Selected issues regarding the reliability-operational assessment of electronic transport systems with regard to electromagnetic interference
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The Impact of Strong Electromagnetic Pulses on the Operation Process of Electronic Equipment and Systems Used in Intelligent Buildings
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Protective and Suppressing Electromagnetic Interference Properties of Epoxy Coatings Containing Nano-Sized NiZn Ferrites
PublicationNano-crystalline ferrites with the chemical formula NixZn(1−x)Fe2O4, where x = 0, 0.2, 0.4, 0.6, 0.8, 1.0, were synthesized using a co-precipitation method. The obtained ferrites were investigated by X-ray diffraction (XRD). The corrosion inhibiting behavior of nano-sized ferrites was tested using carbon steel samples and 10% aqueous ferrite extracts. Results were compared with previous data obtained for micro-sized ceramic ferrites....
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Jakub Konkol dr inż.
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Exploring perceptions of pro environmental educational mobile applications based on semantic field analysis
PublicationThe paper aims to identify multidimensional perceptions of mobile apps by their users. Special attention has been paid to pro-environmental educational apps. Semantic field analysis and measurement of emotional temperatures were performed to achieve this goal. Transcripts from seven focus group interviews were used as research material. The results indicate that functionality based on a reward or benefit system reinforces environmentally...
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Old Problems - New Solutions: Conversion of Capitals as a Tool for Shaping the Competitive Position in the Economic Field
PublicationThe acts and operations any social actor effectuates in each of the logically distinguished spheres of reality are conditioned by many factors, among which a reliable analysis of the strengths and weaknesses of an agent should be considered of utmost importance. The concept of capitals presented in this article divides the quantity of resources available to all acting agents into four main categories (which allows for determining...
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Old Problems - New Solutions: Conversion of Capitals as a Tool for Shaping the Competitive Position in the Economic Field
PublicationThe acts and operations any social actor effectuates in each of the logically distinguished spheres of reality are conditioned by many factors, among which a reliable analysis of the strengths and weaknesses of an agent should be considered of utmost importance. The concept of capitals presented in this article divides the quantity of resources available to all acting agents into four main categories (which allows for determining...
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Deterministic versus stochastic modelling of unsaturated flow in a sandy field soil based on dual tracer breakthrough data
PublicationThe 216 km2 Neuenhagen Millcreeck catchment can be characterized as a drought sensitive landscape in NE Germany. It is therefore a fundamental human interest to understand how water that fell as precipitation moves through the unsaturated soils and recharges groundwater. Additionally, a better knowledge of nutrient transport from soil to groundwater is important also, especially in landscapes with light sandy soils. For a better...
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Electro-chemo-mechanical properties in nanostructured Ca-doped ceria (CDC) by field assisted sintering
PublicationRecent investigations have shown that highly oxygen defective cerium oxides generate non-classical electrostriction that is superior to lead-based ferroelectrics. In this work, we report the effect of field-assisted spark plasma sintering (SPS) on electro-chemo-mechanical properties of calcium doped ceria (CDC). Nanometric powders of Ca.10 nm are rapidly consolidated to form polycrystalline nanostructures with a high degree of...
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2022/2023_LATO Modern Techniques in Control Theory - Nowy
e-Learning CoursesWykład i ćwiczenia z przedmiotu Nowoczesne metody teorii sterowania
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Theory of Urban Design sem I MGR ARCH
e-Learning CoursesW ramach kursu zamieszcozne zostaną treści programowe dla grupy angielskiej na kierunku magisterkim Architektura
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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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Low-cost multiband compact branch-line coupler design using response features and automated EM model fidelity adjustment
PublicationDesign closure of compact microwave components is a challenging problem because of significant electromagnetic (EM) cross-couplings in densely arranged layouts. A separate issue is a large number of designable parameters resulting from replacement of conventional transmission line sections by compact microstrip resonant cells. This increases complexity of the design optimization problem and requires employment of expensive high-fidelity...
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Machine-Learning-Based Global Optimization of Microwave Passives with Variable-Fidelity EM Models and Response Features
PublicationMaximizing microwave passive component performance demands precise parameter tuning, particularly as modern circuits grow increasingly intricate. Yet, achieving this often requires a comprehensive approach due to their complex geometries and miniaturized structures. However, the computational burden of optimizing these components via full-wave electromagnetic (EM) simulations is substantial. EM analysis remains crucial for circuit...
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Microfluidically Frequency-Reconfigurable Compact Self-Quadruplexing Tunable Antenna with High Isolation Based on Substrate Integrated Waveguide
PublicationThis communication presents a novel concept of microfluidically frequency-reconfigurable self-quadruplexing tunable antenna for quad-band applications. At the initial design stage, a substrate-integrated square cavity is divided into four unequal quarter-mode cavity resonators by inserting an X-shaped slot on the top surface of the cavity. Applying four 50-ohm microstrip feed-lines to these four quarter-mode cavity resonators enables...
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Variable Data Structures and Customized Deep Learning Surrogates for Computationally Efficient and Reliable Characterization of Buried Objects
PublicationIn this study, in order to characterize the buried object via deep-learning-based surrogate modeling approach, 3-D full-wave electromagnetic simulations of a GPR model has been used. The task is to predict simultaneously and independent of each characteristic parameters of a buried object of several radii at different positions (depth and lateral position) in various dispersive subsurface media. This study has analyzed variable...
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Accelerated Parameter Tuning of Antenna Structures by Means of Response Features and Principal Directions
PublicationPopularity of numerical optimization has been steadily on the rise in the design of modern antenna systems. Resorting to mathematically rigorous parameter tuning methods is a matter of practical necessity as interactive techniques (e.g., parameter sweeping) are no longer adequate when handling several performance figures over multi-dimensional parameter spaces. The most common design scenarios involve local tuning since decent...
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An electric ring thruster as auxiliary manoeuvring propulsion system for watercraft - construction analysis
PublicationThe reported project aimed at examining properties and purposefulness of use of modern electromagneticbearings for a screw propeller in a prototype version of a synchronous ring motor with rare earths magnets.Bearings of this type generate electromagnetic forces which keep the rotor in a state of levitation. Therotating machine with magnetic bearings can work in any environment which reveals diamagnetic properties(air, vacuum,...
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Study of anticorrosion and microwave absprption properties of NiZn ferrite pigments
PublicationPurpose - The purpose of this paper is to report the electrochemical verification of anticorrosive properties of NiZn ferrites as pigments in protective coatings and evaluation of their microwave absorbing properties. Design/methodology/approach - Ferrites, represented by formula NixZn(1-x)Fe2O4, where x=0, 0.2, 0.4, 0.6, 0.8, 1.0, were synthesized using a ceramic method. The samples of ferrites were examined by X-ray diffraction...
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Low-Cost and Highly-Accurate Behavioral Modeling of Antenna Structures by Means of Knowledge-Based Domain-Constrained Deep Learning Surrogates
PublicationThe 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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Rapid Yield Optimization of Miniaturized Microwave Passives by Response Features and Variable-Fidelity EM Simulations
PublicationThe operation of high-frequency devices, including microwave passive components, can be impaired by fabrication tolerances but also incomplete knowledge concerning operating conditions (temperature, input power levels) and material parameters (e.g., substrate permittivity). Although the accuracy of manufacturing processes is always limited, the effects of parameter deviations can be accounted for in advance at the design phase...
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Rapid Antenna Optimization with Restricted Sensitivity Updates by Automated Dominant Direction Identification
PublicationMeticulous tuning of geometry parameters turns pivotal in improving performance of antenna systems. It is more and more often realized using formal optimization methods, which is demonstrably the most efficient way of handling multiple design variables, objectives, and constraints. Although in some cases a need for launching global search arises, a typical design scenario only requires local optimization, especially when a decent...
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Expedited Metaheuristic-Based Antenna Optimization Using EM Model Resolution Management
PublicationDesign of modern antenna systems heavily relies on numerical opti-mization methods. Their primary purpose is performance improvement by tun-ing of geometry and material parameters of the antenna under study. For relia-bility, the process has to be conducted using full-wave electromagnetic (EM) simulation models, which are associated with sizable computational expendi-tures. The problem is aggravated in the case of global optimization,...
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Low-cost multi-objective optimization and experimental validation of UWB MIMO antenna
PublicationPurpose–The purpose of this paper is to validate methodologies for expedited multi-objective designoptimization of complex antenna structures both numerically and experimentally.Design/methodology/approach–The task of identifying the best possible trade-offs between theantenna size and its electrical performance is formulated as multi-objective optimization problem.Algorithmic frameworks are described for finding Pareto-optimal...
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Computationally Efficient Design Optimization of Compact Microwave and Antenna Structures
PublicationMiniaturization is one of the important concerns of contemporary wireless communication systems, especially regarding their passive microwave components, such as filters, couplers, power dividers, etc., as well as antennas. It is also very challenging, because adequate performance evaluation of such components requires full-wave electromagnetic (EM) simulation, which is computationally expensive. Although high-fidelity EM analysis...
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Improved Modeling of Microwave Structures Using Performance-Driven Fully-Connected Regression Surrogate
PublicationFast replacement models (or surrogates) have been widely applied in the recent years to accelerate simulation-driven design procedures in microwave engineering. The fundamental reason is a considerable—and often prohibitive—CPU cost of massive full-wave electromagnetic (EM) analyses related to solving common tasks such as parametric optimization or uncertainty quantification. The most popular class of surrogates are data-driven...
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Expedited Acquisition of Database Designs for Reduced-Cost Performance-Driven Modeling and Rapid Dimension Scaling of Antenna Structures
PublicationFast replacement models have been playing an increasing role in high-frequency electronics, including the design of antenna structures. Their role is to improve computational efficiency of the procedures that normally entail large numbers of expensive full-wave electromagnetic (EM) simulations, e.g., parametric optimization or uncertainty quantification. Recently introduced performance-driven modeling methods, such as the nested...
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Constrained multi-objective optimization of compact microwave circuits by design triangulation and pareto front interpolation
PublicationDevelopment of microwave components is an inherently multi-objective task. This is especially pertinent to the design closure stage, i.e., final adjustment of geometry and/or material parameters carried out to improve the electrical performance of the system. The design goals are often conflicting so that the improvement of one normally leads to a degradation of others. Compact microwave passives constitute a representative case:...
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Global Design Optimization of Microwave Circuits Using Response Feature Inverse Surrogates
PublicationModern microwave design has become heavily reliant on full-wave electromagnetic (EM) simulation tools, which are necessary for accurate evaluation of microwave components. Consequently, it is also indispensable for their development, especially the adjustment of geometry parameters, oriented towards performance improvement. However, EM-driven optimization procedures incur considerable computational expenses, which may become impractical...
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Reduced-Cost Design Optimization of High-Frequency Structures Using Adaptive Jacobian Updates
PublicationElectromagnetic (EM) analysis is the primary tool utilized in the design of high-frequency structures. In vast majority of cases, simpler models (e.g., equivalent networks or analytical ones) are either not available or lack accuracy: they can only be used to yield initial designs that need to be further tuned. Consequently, EM-driven adjustment of geometry and/or material parameters of microwave and antenna components is a necessary...
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Design-Oriented Two-Stage Surrogate Modeling of Miniaturized Microstrip Circuits with Dimensionality Reduction
PublicationContemporary microwave design heavily relies on full-wave electromagnetic (EM) simulation tools. This is especially the case for miniaturized devices where EM cross-coupling effects cannot be adequately accounted for using equivalent network models. Unfortunately, EM analysis incurs considerable computational expenses, which becomes a bottleneck whenever multiple evaluations are required. Common simulation-based design tasks include...