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Wyniki wyszukiwania dla: ANTENNA MINIATURIZATION, SURFACE MOUNT DESIGN (SMD), CONSTRAINED OPTIMIZATION, EM-DRIVEN DE-SIGN, MULTI-FIDELITY SIMULATIONS
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Expedited Re-Design of Multi-Band Passive Microwave Circuits Using Orthogonal Scaling Directions and Gradient-Based Tuning
PublikacjaGeometry scaling of microwave circuits is an essential but challenging task. In particular, the employment of a given passive structure in a different application area often requires re-adjustment of the operating frequencies/bands while maintaining top performance. Achieving this necessitates utilization of numerical optimization methods. Nonetheless, if the intended frequencies are distant from the ones at the starting point,...
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A Geometrically Simple Compact Wideband Circularly Polarized Antenna
PublikacjaA compact broadband wide-slot circular polarization (CP) antenna is proposed. An inverted L-shape parasitic strip at the open end of a microstrip line extension and a slot modification is applied to attain wideband CP. The advantage of this technique is simplicity which makes it readily re-designable for different frequency bands. To demonstrate the concept, three designs working at different frequencies are obtained. The redesign...
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Shielded HMSIW-based frequency-tunable self-quadruplexing antenna using different solid/liquid dielectrics
PublikacjaThis article proposes a frequency-tunable self-quadruplexing antenna based on a shielded half-mode substrate integrated waveguide (S-HMSIW). In order to reduce the size of the HMSIW cavity resonator and to obtain quad-band characteristics, a modied E-shaped slot is engraved on the top of the metal. The experimental validation is carried out after analyzing the data using a circuit model. Flexibility of each resonant frequency is...
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Accelerated simulation-driven design optimisation of compact couplers by means of two-level space mapping
PublikacjaIn this study, the authors discuss a robust and efficient technique for rapid design of compact couplers. The approach exploits two-level space mapping (SM) correction of an equivalent circuit model of the coupler structure under design. The first SM layer (local correction) is utilised to ensure good matching between the equivalent circuit and the electromagnetic model at the component level. Subsequent global correction allows...
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Compact Dual-Polarized Corrugated Horn Antenna for Satellite Communications
PublikacjaIn this paper, a structure and design procedure of a novel compact dual-polarized corrugated horn antenna with high gain and a stable phase center for satellite communication is presented. The antenna incorporates an Ortho-Mode Transducer (OMT), a mode converter, and a corrugated structure. The compact OMT section is designed to be fed by standard WR-75 waveguides. The proposed compact design utilizes only ten corrugated slots...
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A system for Direction-Of-Arrival estimation in ISM 2.4 GHz frequency band based on ESPAR antenna and SDR technology
PublikacjaDetermination of the direction of the signal arrival (DOA) finds many applications in various areas of science and industry. Knowledge of DOA is used, among others to determine the position of a satellite with a low Earth orbit (LEO), localization of people and things as well as in research of wireless communication systems, for instance the determination of the number of...
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Tolerance-Aware Optimization of Microwave Circuits by Means of Principal Directions and Domain-Restricted Metamodels
PublikacjaPractical microwave design is most often carried out in the nominal sense. Yet, in some cases, performance degradation due to uncertainties may lead to the system failing to meet the prescribed specifications. Reliable uncertainty quantification (UQ) is therefore important yet intricate from numerical standpoint, especially when the circuit at hand is to be evaluated using electromagnetic (EM) simulation tools. Tolerance-aware...
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Inverse and forward surrogate models for expedited design optimization of unequal-power-split patch couplers
PublikacjaIn the paper, a procedure for precise and expedited design optimization of unequal power split patchcouplers is proposed. Our methodology aims at identifying the coupler dimensions that correspond to thecircuit operating at the requested frequency and featuring a required power split. At the same time, thedesign process is supposed to be computationally efficient. The proposed methodology involves two typesof auxiliary models (surrogates):...
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Extraction of antenna pattern from near field antenna measurements distorted by undesired emission
PublikacjaIn this paper authors present experimental correction of antenna pattern obtained from near field measurements when they are distorted by determined electromagnetic emission. Such situation may be met e.g. when feeding or supply subsystem interacts with antenna radiation pattern due to self-emission. Presented results of experiments show effectiveness of extraction of antenna pattern utilizing near field antenna measurements.
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Efecto contagio en el uso del voto electrónico en Estonia: de las elecciones a otros niveles de la administración pública y la sociedad
PublikacjaEstonia, cuarto país más pequeño de la Unión Europea tras Luxemburgo, Chipre y Malta, con una población que no alcanza el millón y medio de habitantes, ha sido en los últimos años objeto de atención mediática internacional por considerarlo the World’s more digital country (GREENWALD, 2018) , the first “Digital” Country (LUFKIN, 2017) o the Digital Republic (HELLER, 2017); así como uno de los referentes en el mundo académico en...
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Influence of ESPAR antenna radiation patterns shape on PPCC-based DoA estimation accuracy
PublikacjaIn the article, we show the influence of three different electronically steerable parasitic array radiator (ESPAR) antenna radiation patterns on the overall direction of arrival (DoA) estimation accuracy when power-pattern cross-correlation (PPCC) algorithm, relying on received signal strength (RSS) values, is used for the estimation. The ESPAR antenna designs were obtained for three optimization goals, which resulted in different...
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Optimization of a Fabry-Perot Sensing Interferometer design for an optical fiber sensor of hematocrit level
PublikacjaContinuous measurement of the hemato crit level in blo o d can p otentially b e p erformed using optical bre sensors. The FabryPerot interferometric sensors are a promising candidate in this application. The most imp ortant step in the design of the sensor is design of the sensing interferometer. Adequate cavity length and high interference contrast are two most imp ortant requirements in this application. The design metho d of...
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Process Optimization for Acid Hydrolysis and Characterization of Bioethanol from Leftover Injera Waste by Using Response Surface Methodology: Central Composite Design
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Design-Oriented Two-Stage Surrogate Modeling of Miniaturized Microstrip Circuits with Dimensionality Reduction
PublikacjaContemporary 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...
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Book review: Simulation-Driven Design Optimisation and Modelling for Microwave Engineering
PublikacjaCelem książki jest przedstawienie aktualnego stanu badań dotyczących projektowania układów mikrofalowych poprzez modelowanie i optymalizacje wspomagane symulacjami elektromagnetycznymi. Grupa międzynarodowych ekspertów zajmujących się rożnymi aspektami komputerowo wspomaganego projektowania układów mikrofalowych, podsumowuje i dokonuje przeglądu ostatnich osiągnięć w tej dziedzinie oraz przedstawia szereg praktycznych zastosowań....
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Design of dimensionally stable composites using efficient global optimization method
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Initializing the EM Algorithm for Univariate Gaussian, Multi-Component, Heteroscedastic Mixture Models by Dynamic Programming Partitions
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Multicriteria Optimization Approach to Design and Operation of District Heating Supply System over its Life Cycle
PublikacjaDistrict Heating (DH) systems are commonly supplied using local heat sources. Nowadays, modern insulation materials allow for effective and economically viable heat transportation over long distances (over 20 km). In the paper a method for optimized selection of design and operating parameters of long distance Heat Transportation System (HTS) is proposed. The method allows for evaluation of feasibility and effectivity of heat transportation...
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Miniaturized Metal-Mountable U-shaped Inductive-Coupling-Fed UHF RFID Tag Antenna with Defected Microstrip Surface
PublikacjaThis study presents a novel miniature ultra-high frequency (UHF) radio frequency identification (RFID) tag for metallic objects. Its arrangement includes a U-shaped feeder, which is inductively coupled to two E-type connected patches. Size reduction is achieved by means of utilizing the U-shaped feeder, and introducing a defection in the connection between the two E-type patches. The defection in the connection area between the...
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OROMACS: A Design Framework for Multi-agent Control System
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Low-Cost Quasi-Global Optimization of Expensive Electromagnetic Simulation Models by Inverse Surrogates and Response Features
PublikacjaConceptual design of contemporary high-frequency structures is typically followed by a careful tuning of their parameters, predominantly the geometry ones. The process aims at improving the relevant performance figures, and may be quite expensive. The reason is that conventional design methods, e.g., based on analytical or equivalent network models, often only yield rough initial designs. This is especially the case for miniaturized...
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Cień Boga w ogrodzie filozofa. Parc de La Villette w Paryżu w kontekście filozofii chôry
PublikacjaKsiążka „Cień Boga w ogrodzie filozofa. Parc de La Villette w Paryżu w kontekście filozofii chôry” przedstawia filozoficzne dyskusje, jakie towarzyszyły projektowaniu rozległego parku w paryskiej dzielnicy La Villette. Na teoretyczne założenia parku złożyły się teksty Bernarda Tschumiego, w których kwestionował on tradycyjne sposoby tworzenia dzieła architektury postulując w zamian zastosowanie długiego szeregu...
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High-Gain Compact Circularly Polarized X-Band Superstrate Antenna for CubeSat Applications
PublikacjaIn this letter, a concept of high-gain circularly polarized X-band antenna employing a partially reflecting surface (PRS) has been presented. In the initial antenna analysis, the influence of parasitic elements size in the PRS structure on antenna radiation pattern parameters has been investigated and the optimal arrangement of the elements has been identified. The proposed antenna provides wide bandwidth of return loss above 10...
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Feedline Alterations for Optimization-Based Design of Compact Super-Wideband MIMO Antennas in Parallel Configuration
PublikacjaThis 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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An Efficient Framework For Fast Computer Aided Design of Microwave Circuits Based on the Higher-Order 3D Finite-Element Method
PublikacjaIn this paper, an efficient computational framework for the full-wave design by optimization of complex microwave passive devices, such as antennas, filters, and multiplexers, is described. The framework consists of a computational engine, a 3D object modeler, and a graphical user interface. The computational engine, which is based on a finite element method with curvilinear higher-order tetrahedral elements, is coupled with built-in...
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Sign Systems Studies
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Sign Language Studies
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Sign Language & Linguistics
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Strain energy density and entire fracture surface parameters relationship for LCF life prediction of additively manufactured 18Ni300 steel
PublikacjaIn this study, the connection between total strain energy density and fracture surface topography is investigated in additively manufactured maraging steel exposed to low-cycle fatigue loading. The specimens were fabricated using laser beam powder bed fusion (LB-PBF) and examined under fully-reversed strain-controlled setup at strain amplitudes scale from 0.3% to 1.0%. The post-mortem fracture surfaces were explored using a non-contact...
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Measurements of electrically small antenna radiation patterns in non-anechoic environments using TGM
Dane BadawczeThe dataset contains raw and processed measurements of radiation pattern characteristics performed in non-anechoic regime for four antenna structures: a spline-parameterized Vivaldi structure, a compact spline-based monopole, super-ultrawideband antenna, and a quasi-Yagi component. The responses have been obtained at the selected frequencies of interest...
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Shape similarity to alphanumeric sign - proposition of new criterion.
PublikacjaArtykuł opisuje różne podejścia do określania kształtu. Zawiera analizę ich użyteczności do wyznaczania podobieństwa do litery lub cyfry (znaku alfanumerycznego). Umiejętność sprawdzenia podobieństwa kształtu do znaku alfanumerycznego jest wymagana do oszacowania jakości wstępnego przetwarzania podczas automatycznego rozpoznawaniu maszynopisów. Konieczna jest również do znajdowania ''literopodobnych'' obszarów wśród innych kształtów...
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Języki migowe w Finlandii [Sign languages in Finland]
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Low-Cost Automated Design of Compact Branch-Line Couplers
PublikacjaBranch-line couplers (BLCs) are important components of wireless communication systems. Conventional BLCs are often characterized by large footprints which make miniaturization an important prerequisite for their application in modern devices. State-of-the-art approaches to design of compact BLCs are largely based on the use of high-permittivity substrates and multi-layer topologies. Alternative methods involve replacement of transmission-line...
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Single-Anchor Indoor Localization Using ESPAR Antenna
PublikacjaIn this paper a new single-anchor indoor localization concept employing Electronically Steerable Parasitic Array Radiator (ESPAR) antenna has been proposed. The new concept uses a simple fingerprinting algorithm adopted to work with directional main beam and narrow minimum radiation patterns of ESPAR antenna that scans 360° area around the base station, while the signal strength received from a mobile terminal is being recorded...
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Zdzisław Kowalczuk prof. dr hab. inż.
OsobyW 1978 ukończył studia w zakresie automatyki i informatyki na Wydziale Elektroniki Politechniki Gdańskiej, następnie rozpoczął pracę na macierzystej uczelni. W 1986 obronił pracę doktorską, w 1993 habilitował się na Politechnice Śląskiej na podstawie pracy Dyskretne modele w projektowaniu układów sterowania. W 1996 mianowany profesorem nadzwyczajnym, w 2003 otrzymał tytuł profesora nauk technicznych. W 2006 założył i od tego czasu...
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Molecular Dynamics to Predict Cryo-EM: Capturing Transitions and Short-Lived Conformational States of Biomolecules
PublikacjaSingle-particle cryogenic electron microscopy (cryo-EM) has revolutionized the field of the structural biology, providing an access to the atomic resolution structures of large biomolecular complexes in their near-native environment. Today’s cryo-EM maps can frequently reach the atomic-level resolution, while often containing a range of resolutions, with conformationally variable regions obtained at 6 Å or worse. Low resolution...
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Miniature reconfigurable antenna
PublikacjaThis work concerns the design of a miniature, low-profile reconfigurable antenna based on Huygens metamaterial sources for frequency f0 = 2.45 GHz. Two planar Huygens sources were designed consisting of near-field resonators. Sources are excited from a specially designed reconfigurable control system. Thanks to the two PIN diodes, the system can realize two cardioid radiation characteristics with...
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International Journal for Simulation and Multidisciplinary Design Optimization
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Simple 60 GHz Switched Beam Antenna for 5G Millimeter-Wave Applications
PublikacjaA new 60 GHz band single-input switched beam antenna is proposed for the fifth-generation (5G) millimeter-wave network applications. The presented design is capable of electronically switching the main beam in two different directions via a proposed microstrip-line-to-slotline single-pole dual-throw (SPDT) switch based on commercially available p-i-n diodes. The antenna is fabricated in a low-cost printed circuit board process...
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Survey of multi-objective portfolio optimization by linear and mixed integer programming
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Adaptive Wavelet-Based Correction of Non-Anechoic Antenna Measurements
PublikacjaNon-anechoic measurements represent an affordable alternative to evaluation of antenna performance in expensive, dedicated facilities. Due to interferences and noise from external sources of EM radiation, far-field results obtained in non-ideal conditions require additional post-processing. Conventional correction algorithms rely on manual tuning of parameters, which make them unsuitable for reliable testing of prototypes. In this...
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Tadeusz Stolarski prof. dr hab. inż.
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Acceleration of Electromagnetic Simulations on Reconfigurable FPGA Card
PublikacjaIn this contribution, the hardware acceleration of electromagnetic simulations on the reconfigurable field-programmable-gate-array (FPGA) card is presented. In the developed implementation of scientific computations, the matrix-assembly phase of the method of moments (MoM) is accelerated on the Xilinx Alveo U200 card. The computational method involves discretization of the frequency-domain mixed potential integral equation using...
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Design of cum driven hydrostatically discharged commutation unit of a new axial pump.
PublikacjaPrzedstawiono analizę wpływu zarysu krzywki sterującej mechanizmem rozrządu na własności pompy. Przeanalizowano zarysy sinusoidalne i złożone. W oparciu o wyniki analiz wytypowano optymalny zarys krzywki sterującej.
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Tecnología y Democracia ¿Un amor de pandemia o una relación estable?
PublikacjaPrologar una obra como esta es un privilegio y una responsabilidad. Es un privilegio en tanto que da paso a un seguido de contribuciones de gran calado y relevancia académica que contribuyen a la mejora del conocimiento existente acerca de la relación entre la tecnología y el funcionamiento de la democracia. Es una responsabilidad en el sentido que debe poner sobre la mesa algunas de las cuestiones abiertas de la disciplina y como...
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Microfluidically Frequency-Reconfigurable Compact Self-Quadruplexing Tunable Antenna with High Isolation Based on Substrate Integrated Waveguide
PublikacjaThis 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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Highly Miniaturized Self-Diplexed U-Shaped Slot Antenna Based on Shielded QMSIW
PublikacjaThis article presents an efficient yet simple design approach to highly miniaturized cavity-backed self-diplexing antenna (SDA) with high-isolation. The structure employs a shielded quarter-mode substrate integrated waveguide (QMSIW). Two U-shaped slots are engraved on the top conducting plane, which realize two frequency bands and significant size reduction. The slots are excited by two independent 50Ω orthogonal feed-lines to...
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Design of a microrobotic wrist for needle laparoscopic surgery
PublikacjaThe paper addresses the design of a micro wrist for needle laparoscopic surgery (needlescopy) using MEMS technology and an original 3 degree of freedom, 3D architecture. Advancement in needlescopy drives the development of multi-dof micro-tools 1-2mmin diameter with 3D mobility but standard available fabricationtechniques are for 2.5D structures. The paper discusses thedevelopment steps and design solutions for the realization...
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Dual-band antenna with improved gain for WLAN and ISM applications
PublikacjaIn this Letter, a dual-band antenna with an improved gain is proposed. The structure features 9.7 and 10.4 dBi gain within 2.4 GHz to 2.5 GHz and 5 GHz to 6 GHz bands, respectively. This makes it suitable for WLAN and ISM applications. The structure comprises an asymmetrical pair of radiators and slots suspended over a reflector. The antenna is optimised in a two-stage process using a trust-region-based gradient search algorithm....
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Prediction of manoeuvring abilities of 10000 DWT pod-driven coastal tanker
PublikacjaThis paper aims to present a new approach in the prediction of manoeuvring abilities of pod-driven ships. A new mathematical model of motions based on MMG methodology was developed and a new type of description of forces acting on azimuth drives is presented. Captive model tests of medium-size coastal tanker and pod open water tests were carried out in CTO S.A. (Ship Design and Research Centre S.A.) to obtain hull hydrodynamic derivatives...