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Search results for: WIR
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Feedline Alterations for Optimization-Based Design of Compact Super-Wideband MIMO Antennas in Parallel Configuration
PublicationThis letter presents a technique for size reduction of wideband multiple-input-multiple-output (MIMO) antennas. Our approach is a two-stage procedure. At the first stage, the antenna structure is modified to improve its impedance matching. This is achieved through incorporation of an n-section tapered feedline, followed by reoptimization of geometry parameters. Reducing the maximum in-band reflection well beyond the acceptance...
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Characteristics of the polarised off-body channel in indoor environments
PublicationThis paper addresses the depolarisation effect in off-body body area networks channels, based on measurements performed at 2.45 GHz in an indoor environment. Seven different scenarios, involving both static and dynamic users, were considered, taking a statistical perspective. The analysis of the cross-polarisation discrimination is performed, as well as the analysis of path loss in co- and cross-polarised channels. Results show...
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A Stabilized Complex LOBPCG Eigensolver for the Analysis of Moderately Lossy EM Structures
PublicationThis letter proposes a stabilized locally optimal block preconditioned conjugate gradient method for computing selected eigenvalues for complex symmetric generalized non-Hermitian eigenproblems. Effectiveness of the presented approach is demonstrated for a moderately lossy dual-mode dielectric resonator, modeled using finite-element method with higher order elements
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Uniform sampling in constrained domains for low-cost surrogate modeling of antenna input characteristics
PublicationIn this letter, a design of experiments technique that permits uniform sampling in constrained domains is proposed. The discussed method is applied to generate training data for construction of fast replacement models (surrogates) of antenna input characteristics. The modeling process is design-oriented with the surrogate domain spanned by a set of reference designs optimized with respect to the performance figures and/or operating...
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RSS-based DoA Estimation Using ESPAR Antennas and Interpolated Radiation Patterns
PublicationIn this letter, it is shown how an algorithm, which employs received signal strength (RSS) values in order to estimate direction-of-arrival (DoA) of impinging signals in wireless sensor network (WSN) nodes equipped with electronically steerable parasitic array radiator (ESPAR) antennas, can easily be improved by applying an interpolation algorithm to radiation patterns recorded in the calibration phase of the DoA estimation process....
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Simple 2-D Direction-of-Arrival Estimation Using an ESPAR Antenna
PublicationIn this letter, it has been shown how an electronically steerable parasitic array radiator (ESPAR) antenna can be used for 2-D direction-of-arrival (DoA) estimation employing received signal strength (RSS) values only. The proposed approach relies on changes in RSS values recorded at the antenna output port observed for different vertical and horizontal directions, while antenna’s main beam sweeps 360° area around the ESPAR antenna. Based...
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Objective relaxation algorithm for reliable simulation-driven size reduction of antenna structure
PublicationThis letter investigates reliable size reduction of antennas through electromagnetic-driven optimization. It is demonstrated that conventional formulation of the design task by direct footprint miniaturization with imposing constraints on electrical performance parameters may not lead to optimum results. The reason is that—in a typical antenna structure—only a few geometry parameters explicitly determine the antenna footprint,...
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A Simple-Topology Compact Broadband Circularly Polarized Antenna With Unidirectional Radiation Pattern
PublicationIn this letter, a geometrically simple, reflector-backed single-point-fed circularly polarized (CP) antenna with unidirectional radiation pattern is presented. The structure comprises a simple coplanar waveguide (CPW) feeding circuit with an open slot etched on one side of the coplanar ground. The enhanced CP bandwidth is obtained by combining the loop mode, the slot mode, and the asymmetrical configuration of the coplanar ground...
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A Compact Circularly Polarized Antenna With Directional Pattern for Wearable Off-Body Communications
PublicationThis letter presents a geometrically simple and compact circularly polarized (CP) antenna with unidirectional radiation characteristics for off-body communications. The proposed antenna is based on a microstrip line monopole extension from a coplanar waveguide (CPW) and a protruded stub from one side of the coplanar ground plane along the length of the monopole. The orthogonal components of equal amplitudes required for circular...
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Pareto Ranking Bisection Algorithm for Expedited Multi-Objective Optimization of Antenna Structures
PublicationThe purpose of this letter is introduction of a novel methodology for expedited multi-objective design of antenna structures. The key component of the presented approach is fast identification of the initial representation of the Pareto front (i.e., a set of design representing the best possible trade-offs between conflicting objectives) using a Pareto-ranking bisection algorithm. The algorithm finds a discrete set of Pareto-optimal...
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On Reduced-Cost Design-Oriented Constrained Surrogate Modeling of Antenna Structures
PublicationDesign of contemporary antenna structures heavily relies on full-wave electromagnetic (EM) simulation models. Such models are essential to ensure reliability of evaluating antenna characteristics, yet, they are computationally expensive and therefore unsuitable for handling tasks that require multiple analyses, e.g., parametric optimization. The cost issue can be alleviated by using fast surrogate models. Conventional data-driven...
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Zero-Pole Electromagnetic Optimization
PublicationA fast technique for the full-wave optimization of transmission or reflection properties of general linear timeinvariant high-frequency components is proposed. The method is based on the zeros and poles of the rational function representing the scattering parameters of the device being designed and it is the generalization of the technique developed for the design by optimization of microwave filters. The performance of the proposed...
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Electromagnetic curtain effect and tunneling properties of multilayered periodic structures
PublicationArtykuł przedstawia analizę rozpraszania fali elektromagnetycznej na wielowarstwowych strukturach periodycznych. W analizowanych strukturach zaobserwowano efekt tunelowania fali oraz efekt przestrajania pasm zaporowych/przepustowych (efekt kurtyny elektromagnetycznej)
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Pin-on-Substrate Gap Waveguide: An Extremely Low-Cost Realization of High-Performance Gap Waveguide Components
PublicationConsidering the limitations of currently available technologies for the realization of microwave components and antennas, a trade-off between different factors including the efficiency and fabrication cost is required. The main objective of this letter is to propose a novel method for the realization of gap waveguides (GWGs) that take advantage of conventional PCB fabrication technology, thus are low cost and light weight. Moreover,...
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Absorbing Boundary Conditions Derived Based on Pauli Matrices Algebra
PublicationIn this letter, we demonstrate that a set of absorbing boundary conditions (ABCs) for numerical simulations of waves, proposed originally by Engquist and Majda and later generalized by Trefethen and Halpern, can alternatively be derived with the use of Pauli matrices algebra. Hence a novel approach to the derivation of one-way wave equations in electromagnetics is proposed. That is, the classical wave equation can be factorized...
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Emotions in Human-Computer Interaction Research Group (EMORG)
Research Teams* rozpoznawanie emocji użytkownika (ang. emotion elicitation) * reprezentację informacji o emocjach użytkownika (ang. emotion representation/ affect modelling) i zarządzanie nimi * ekspresję emocji lub reakcję na emocje przez programy np. przez wirtualne postaci (ang. affect expression) * wybrane zastosowania to badanie użyteczności oprogramowania rozszerzone o aspekty emocjonalne * badania wzorców behawioralnych w połączeniu...
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Katedra Inżynierii Zarządzania Operacyjnego
Research Teams* procesy i zarządzanie innowacjami w organizacjach gospodarczych * procesy i zarządzanie zmianą w systemach produkcyjnych * zarządzanie projektami, programami oraz portfolio projektów innowacyjnych i rozwojowych * modelowanie i doskonalenie procesów oraz systemów produkcyjnych * projektowanie i optymalizacja technologii informatycznych w inteligentnych systemach produkcyjnych * ilościowe metody wspomagania decyzji w systemach...
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Sposób regulacji silnika pierścieniowego zasilanego od strony wirnika z falownika prądu, od strony stojana z sieci zasilającej
Inventions -
Katedra Inżynierii Elektrycznej Transportu
Research Teams* Diagnostyka techniczna i monitoring w systemach transportu zelektryfikowanego * Metody diagnostyki technicznej i monitoringu odbieraków prądu oraz górnej sieci trakcyjnej, w szczególności metody wizyjne * Modele matematyczne i symulacyjne odbieraków prądu i górnej sieci trakcyjnej * Modelowanie i analiza elektrotrakcyjnych układów zasilania * Modelowanie i sterowanie napędami elektrycznymi pojazdów * Redukcja zużycia energii...
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An analysis and evaluation of the WeFold collaborative for protein structure prediction and its pipelines in CASP11 and CASP12
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Streamwise vortex interaction with a horseshoe vortex.
PublicationPrzedstawiono próbę oddziaływania wiru wzdłużnego na wir podkowiasty. Wir wzdłużny uzyskano dzięki generatorom powietrznym typu ''jet'' czyli poprzez wydmuch czynnika przez otwory przed opływanym ciałem. Wykazano, że oddziaływanie to może doprowadzić do zmiany struktury przepływu i dezintegrację wiru podkowiastego.
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Wykorzystanie programu LabVIEW do wyznaczania wielkości elektrycznych w układach trójfazowych.
PublicationPodano sposób do obliczania wybranych wielkości elektrycznych obwodów trój- fazowych przy wykorzystaniu programu wirtualnego LabVIEW. Cykl obliczeń przedstawiony jest na przykładziw układu trójprzewodowego z możliwością jego adaptacji na układ czteroprzewodowy. Stworzony do tego celu przyrząd wir- tualny oblicza w kolejności: potencjał punktu neutralnego, napięcia, prądy i kąty fazowe w układach trójprzewodowych i czteroprzewodowych.
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ENERGIEEFFIZIENZ DER ZAHLUNGSOPERATIONEN
PublicationHeute kannman nach verschiedenen Schätzungen mehr als zehn Möglichkeiten nutzen, um Einzelhandelswaren, Dienstleistungen oder geleistete Arbeit zu bezahlen. Die beliebtesten, bedeutendsten und sensibelsten sind Bargeld-und bargeldlose Zahlungen. Als die modernste kann man Kryptowährungzahlungen schätzen. Jede Zahlungsart ist mit Zeit-und Energiekosten für ihre Wartung und dementsprechend mit finanziellen Kosten verbunden....
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Influence of Nitriding and Laser Remelting on Properties of Austenitic Stainless Steel Type X10CrNi18-8 and Cavitation Erosion Resistance
PublicationThe paper presents properties of surface layers. Surface layers were obtained by using low temperature glow–discharge nitriding process and laser remelting carried out on austenitic stainless steel type X10CrNi18-8. Investigations were done by using an Ultra Nanoindentation Tester (UNHT) in the Warsaw Institute of Fundamental Technological Research. The influence of the above mentioned...
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Kurs szkoleniowy
e-Learning CoursesKurs szkoleniowy dla wykładowców - quizy i zadania, tutoriale i nagrania ze spotkań
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DEM investigations of two-dimensional granular vortex- and anti-vortex- structures during plane strain compression.
PublicationDEM investigations of two-dimensional granular vortex- and anti-vortex- structures during plane strain compression.