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Search results for: UWB MONOPOLE
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Liver antioxidant defense after FAAH inhibitor - URB-597 administration to DOCA-salt-induced hypertension in rats
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Low-Cost Multi-Objective Optimization of Antennas By Means Of Generalized Pareto Ranking Bisection Algorithm
PublicationThis paper introduces a generalized Pareto ranking bisection algorithm for low-cost multi-objective design optimization of antenna structures. The algorithm allows for identifying a set of Pareto optimal sets of parameters (that represent the best trade-offs between considered objectives) by iterative partitioning of the intervals connecting previously found designs and executing a Pareto-ranking-based poll search. The initial...
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Design-Oriented Constrained Modeling of Antenna Structures
PublicationFast surrogate models are crucially important to reduce the cost of design process of antenna structures. Due to curse of dimensionality, standard (data-driven) modeling methods exhibit serious limitations concerning the number of independent geometry parameters that can be handled but also (and even more importantly) their parameter ranges. In this work, a design-oriented modeling framework is proposed in which the surrogate is...
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Kwartalnik Naukowy OAP UW "e-Politikon"
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Powszechny niedobór witaminy D u dorosłych z województwa pomorskiego po miesiącach niskiego i wysokiego promieniowania UVB
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Zbigniew Sikora prof. dr hab. inż.
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Triangulation-based Constrained Surrogate Modeling of Antennas
PublicationDesign of contemporary antenna structures is heavily based on full-wave electromagnetic (EM) simulation tools. They provide accuracy but are CPU-intensive. Reduction of EM-driven design procedure cost can be achieved by using fast replacement models (surrogates). Unfortunately, standard modeling techniques are unable to ensure sufficient predictive power for real-world antenna structures (multiple parameters, wide parameter ranges,...
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Accelerated multi-objective design optimization of antennas by surrogate modeling and domain segmentation
PublicationMulti-objective optimization yields indispensable information about the best possible design trade-offs of an antenna structure, yet it is challenging if full-wave electromagnetic (EM) analysis is utilized for performance evaluation. The latter is a necessity for majority of contemporary antennas as it is the only way of achieving acceptable modeling accuracy. In this paper, a procedure for accelerated multi-objective design of...
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SHORT REVIEW AND 3-D FEM ANALYSIS OF BASIC TYPES OF FOUNDATION FOR OFFSHORE WIND TURBINES
PublicationSome problems of the foundations of offshore wind turbines are considered in this paper. A short review is presented on the two basic types of foundations, i.e. monopiles and gravity foundations, including their basic features and applications as well as general design considerations. Also, some issues regarding analysis are discussed, including geotechnical problems and modelling techniques. A numerical model of offshores turbine...
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Low-Cost EM-Simulation-Driven Multi-Objective Optimization of Antennas
PublicationA surrogate-based method for efficient multi-objective antenna optimization is presented. Our technique exploits response surface approximation (RSA) model constructed from sampled low-fidelity antenna model (here, obtained through coarse-discretization EM simulation). The RSA model enables fast determination of the best available trade-offs between conflicting design goals. A low-cost RSA model construction is possible through...
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Numerical optimization of planar antenna structures using trust-region algorithm with adaptively adjusted finite differences
Open Research DataThe dataset contains initial designs and optimization results for three planar structures that include quasi-patch antenna for WLAN applications, compact spline-parameterized monopole dedicated for ultra-wideband applications, as well as rectifier for energy harvesting with enhanced bandwidth. The numerical results for the first two structures are also...
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Narrowband Transmission Quality in Presence of Modified IEEE 802.15.4a Impulse Radio Interference
PublicationThis paper presents results of measurement of narrowband transmission quality in presence of impulse radio UWB interference. IEEE 802.15.4a UWB signal is being used as interferer, also with frame structure modifications which lead to change spectrum of the interference. Equations and coefficients which allow to calculate ratio between power of useful and interference signal are also presented.
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Generalized Pareto ranking bisection for computationally feasible multi-objective antenna optimization
PublicationMulti-objective optimization (MO) allows for obtaining comprehensive information about possible design trade-offs of a given antenna structure. Yet, executing MO using the most popular class of techniques, population-based metaheuristics, may be computationally prohibitive when full-wave EM analysis is utilized for antenna evaluation. In this work, a low-cost and fully deterministic MO methodology is introduced. The proposed generalized...
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Multi-objective design optimization of antenna structures using sequential domain patching with automated patch size deter-mination
PublicationIn this paper, a simple yet efficient and reliable technique for fully automated multi-objective design optimization of antenna structures using sequential domain patching (SDP) is discussed. The optimization procedure according to SDP is a two-step process: (i) obtaining the initial set of Pareto-optimal designs representing the best possible trade-offs between considered conflicting objectives, and (ii) Pareto set refinement...
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Time-domine Dipole Fields in acoustic and Elektromagnetics
PublicationThe ultrawideband (UWB) radio technique presents a challenge not just for technology. The UWB carrier-free pulses act at a close distance, their electromagnetic fields being very different from classic monochromatic plane wave. The author proposes to adapt a time-domian approach to analysis of broadband spherical fields, both acoustic and electromagnetic, in fundamental cases of quasi-point physical sources.
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Database of the illustrative simulations of the nonstandard approximation of the generalized Burgers–Huxley equation
Open Research DataThe presented dataset is a result of numerical analysis of a generalized Burgers–Huxley partial differential equation. An analyzed diffusive partial differential equation consist with nonlinear advection and reaction. The reaction term is a generalized form of the reaction law of the Hodgkin–Huxley model, while the advection is a generalized form of...
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Deep Learning-Based LOS and NLOS Identification in Wireless Body Area Networks
PublicationIn this article, the usage of deep learning (DL) in ultra-wideband (UWB) Wireless Body Area Networks (WBANs) is presented. The developed approach, using channel impulse response, allows higher efficiency in identifying the direct visibility conditions between nodes in off-body communication with comparison to the methods described in the literature. The effectiveness of the proposed deep feedforward neural network was checked on...
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Cost-efficient multi-objective design optimization of antennas in highly-dimensional parameter spaces
PublicationMulti-objective optimization of antenna structures in highly-dimensional parameter spaces is investigated. For expedited design, variable-fidelity EM simulations and domain patching algorithm are utilized. The results obtained for a monopole antenna with 13 geometry parameters are compared with surrogate-assisted optimization involving response surface approximation modeling.
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Correction of far-field measurements obtained in non-anechoic test site
Open Research DataThe dataset contains raw and processed measurements of radiation pattern characteristics performed in non-anechoic regime for two geometrically small antenna structures: a spline-parameterized Vivaldi structure and a compact spline-based monopole. The responses have been obtained at the selected frequencies of interest as a function of mentioned structures...
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Localization in wireless sensor networks using switched parasitic antennas
PublicationA switched parasitic monopole antenna for 2.4 GHz ISM applications is design and investigated in this paper. One of the most promising applications for such switched-beam antennas is localization in wireless sensor networks (WSN). It is demonstrated that the use of this antenna improves accuracy of localization algorithms and allows for reduction of the number of reference nodes in localization system.
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Seiberg-Witten invariants the topological degree and wall crossing formula
PublicationFollowing S. Bauer and M. Furuta we investigate finite dimensional approximations of a monopole map in the case b 1 = 0. We define a certain topological degree which is exactly equal to the Seiberg-Witten invariant. Using homotopy invariance of the topological degree a simple proof of the wall crossing formula is derived.
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Measurements of radiation emission of a portable power bank with a capacity of 5200 mAh
Open Research DataThe dataset contains the emission measurement results that are part of comprehensive tests carried out for portable power banks with different capacities. The measurements were performed in the frequency range from 30 MHz to 3 GHz using a Gigahertz Transverse Electromagnetic (GTEM) cell. The test setup was configured to measure a portable power bank...
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Radiation pattern measurements of geometrically small antennas performed in non-anechoic environments
Open Research DataThe dataset contains unprocessed measurements of radiation pattern characteristics performed in non-anechoic regime for three geometrically small antenna structures: a spline-parameterized Vivaldi structure, a compact spline-based monopole, and a quasi-Yagi geometry with enhanced bandwidth. The responses have been obtained over broad frequency ranges...
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Measurements of electrically small antenna radiation patterns in non-anechoic environments using TGM
Open Research DataThe 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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Solar radiation (PAR, UV-B and UV-A) reaching the sea surface - Gdańsk Deep (2001-2005)
Open Research DataSolar radiation reaching the sea surface was measured in spring (2001, 2003, 2005) and autumn (2002, 2004). For measurements of the photosynthetic active radiation - PAR (400-700 nm), the Ejkelkamp SKP 210 / I 0896 13595 sensor was used, the UV-B radiation (280-315 nm) was measured with the Ejkelkamp SKU 430 0497 14854 sensor, while UV-A (315- 380 nm)...
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Dipolowe anteny planarne do zastosowań w standardzie Ultra-Wide band
PublicationW pracy dokonano przeglądu dipolowych anten planarnych projektowanych dla standardu UWB. Przedstawiono przykładowe promienniki oraz symetryzatory szerokopasmowe, które składają sie na antenę dipolową. porównano dopasowania anten dla wybranych kształtów promienników.
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Simulation-driven design of compact ultra-wideband antenna structures
PublicationPurpose–The purpose of this paper is to investigate strategies and algorithms for expedited designoptimization and explicit size reduction of compact ultra-wideband (UWB) antennas.Design/methodology/approach–Formulation of the compact antenna design problem aiming atexplicit size reduction while maintaining acceptable electrical performance is presented. Algorithmicframeworks are described suitable for handling various design situations...
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Dziedzictwo polsko-ukraińskie T.2 - recenzja pracy pod redakcją Selima Chasbijewicza, Marka Melnyka, Krzysztofa Kluczborskiego [wyd. Inst. Nauk Politycznych UWM w Olsztynie, Olsztyn 2008, s. 500]
PublicationZamierzeniem artykułu jest ukazanie dziedzictwa polsko-ukraińskiego na wielu płaszczyznach by podkreślić jego wieloaspektowość i wielokulturowość. Dziedzictwo polsko-ukraińskie jest możliwe do scharakteryzowania dzięki funkcjonującym przez wieki obszarom pogranicza, na którym dochodziło do zetknięcia się 2-ch społeczeństw i 2-ch kultur ukraińskiej i polskiej.
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Referendum jako wyznacznik modelu demokracji lokalnej (ze szczególnym uw zględnieniem referendum lokalnego w Stanach Zjednoczonych Ameryki)
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Person Tracking in a Ferry Environment Using Ultra-Wide Band Radio Interface
PublicationThis article presents research and analysis of effectiveness of tracking moving people in an environment of passenger ferry, using measurements of propagation time of ultra-wide band radio signal (UWB - Ultra-Wide Band). Constructed measurement stand and results of measurements carried out in a real propagation conditions were shortly discussed.
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Wojciech Toczek dr hab. inż.
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Design of a broadband microstrip crossover for ultra-wideband applications
PublicationW pracy przedstawiono badania skrzyżowań linii mikropaskowych do zastosowań w systemach UWB. W procedurze projektowej wykorzystany został model zastępczy skrzyżowania. W celu poprawy parametrów skrzyżowań zaprojektowano dwie konfiguracje obwodów kompensujących. Wyniki numeryczne zweryfikowane zostały eksperymentalnie. Uzyskano dobrą zgodność pomiędzy rezultatami symulacji oraz pomiarów.
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Lokalizacja osób w środowisku promu pasażerskiego z wykorzystaniem ultra szerokopasmowego interfejsu radiowego
PublicationW niniejszym artykule przedstawiono badania efektywności lokalizowania poruszających się osób w środowisku promu pasażerskiego stosując pomiar czasu propagacji ultraszerokopasmowego sygnału radiowego UWB (Ultra-Wide Band) pomiędzy węzłami odniesienia i terminalem ruchomym. Opisano zbudowane stanowisko badawcze oraz uzyskane wyniki pomiarów przeprowadzonych w warunkach rzeczywistych.
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Tracking body movement for radio channel measurements in BAN with indoor positioning system
PublicationThis paper presents indoor positioning system based on inertial navigation with additional distance measurements using UWB modems and map matching to increase accuracy and eliminate position drift. Such system may be used to track position of human body during radio channel measurements for body area networks. Performance of proposed system and limitations caused by inertial navigation are briefly described.
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Searching by heterogeneous agents
PublicationIn this work we introduce and study a pursuit-evasion game in which the search is performed by heterogeneous entities. We incorporate heterogeneity into the classical edge search problem by considering edge-labeled graphs: once a search strategy initially assigns labels to the searchers, each searcher can be only present on an edge of its own label. We prove that this problem is not monotone even for trees and we give instances...
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Detekcja warunków LOS i NLOS w środowisku wewnątrz budynkowym przy użyciu algorytmu głębokiego uczenia
PublicationW środowisku wewnątrzbudynkowym występuje wiele czynników negatywnie wpływających na transmitowane sygnały. Niniejszy artykuł przedstawia metodę opartą na koncepcji głębokich sieci neuronowych, służącą do detekcji warunków LOS i NLOS w środowisku wewnątrzbudynkowym. Algorytm opracowany i przetestowany został na podstawie pomiarów sygnałów UWB przeprowadzonych w rzeczywistym środowisku wewnątrzbudynkowym.
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IEEE 802.15.4a Impulse Radio Spectrum Shaping by Changes in Pulse Sequence
PublicationThis paper presents one of possible techniques of IEEE 802.15.4a ultra-wideband signal spectrum control, based on changes in sequences of transmitted pulses with very short duration time. This technique can reduce probability of mutual interferences between new ultra-wideband and existing narrowband devices, which may be helpful in further studies on allowing UWB transmission in wider range of spectrum in theEuropean Union.
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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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Narrowband interference suppression in IEEE 802.15.4a ultrawideband receiver
PublicationW referacie przedstawiono metodę redukcji wpływu silnych sygnałów wąskopasmowych na jakość transmisji ultraszerokopasmowej w standardzie IEEE 802.15.4a poprzez modyfikację sekwencji impulsów w odbiorniku korelacyjnym. Opisano strukturę rozpatrywanego odbiornika i sposób tworzenia zmodyfikowanych sekwencji wzorcowych, a także przedstawiono wyniki symulacji komputerowych jakości pracy łącza UWB w obecności zakłóceń o charakterze...
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Zarządzanie cenami w przedsiębiorstwie działającym na oligopolistycznym rynku produktów homogenicznych
PublicationW artykule pokazano ogólne prawidłowości w zakresie kształtowania cen na rynku konkurencji doskonałej, monopolu czystego oraz oligopolu homogenicznego wykorzystując analizę graficzną. Wskazano również możliwości zarządzania cenami w oligopolu działającym na rynku międzynarodowym na podstawie przybliżonego rozwiązania optymalnego dla branży.
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Measurements of radiation emission of a portable power bank with a capacity of 2600 mAh
Open Research DataThe dataset contains the emission measurement results that are part of comprehensive tests carried out for portable power banks with different capacities. The measurements were performed in the frequency range from 30 MHz to 3 GHz using a Gigahertz Transverse Electromagnetic (GTEM) cell. The test setup was configured to measure a portable power bank...
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Social Security. Theory. Law. Practice
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Ujednolicone kryterium oceny stanu kompatybilności międzysystemowej wąsko- i ultraszerokopasmowych systemów radiokomunikacyjnych
PublicationNiniejszy referat zawiera propozycję ujednoliconegokryterium oceny stanu kompatybilności międzysystemowej różnych systemów radiokomunikacyjnych zajmujących to samo pasmo częstotliwości. W szczególności pozwala to na porównywanie różnych typów transmisji ultraszerokopasmowych pod kątem ich odporności na zakłócenia wąskopasmowe oraz wpływu na jakość transmisji wąskopasmowych. Przedstawiono także sposób obliczania szerokościprzedziału...
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Experimental Study of the Influence of Noise Level on the Uncertainty Value in a Measurement System Containing an Analog-to-Digital Converter
Open Research DataFor newly developed measuring systems it is easy to estimate type B uncertainties based on the technical data of the measuring modules applied. However, it is difficult to estimate A type un-certainties due to the unknown type and level of interferences infiltrating into the measuring sys-tem. This is a particularly important problem for measurements...
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Systems of boundary value problems of advanced differential equations
PublicationThis paper considers the existence of extremal solutions to systems of advanced differential equations with corresponding nonlinear boundary conditions. The monotone iterative method is applied to obtain the existence results. An example is provided for illustration.
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Quasi-solutions for generalized second order differential equations with deviating arguments
PublicationThis paper deal with boundary value problems for generalized second order differential equations with deviating arguments. Existence of quasi-solutions and solutions are proved by monotone iterative method. Examples with numerical results are added.
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Fast Multi-Objective Antenna Design Through Variable-Fidelity EM Simulations
PublicationA technique for fast multi-objective antenna optimization is introduced. A kriging interpolation surrogate constructed from sampled coarse-mesh EM simulations is utilized by multi-objective evolutionary algorithm (MOEA) to obtain the initial Pareto front approximation. The surrogate is defined in a subset of the original design space, determined by means of independently optimized individual objectives. Response correction techniques...
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Estimation of a single balun parameters on the base of back-to-back measurements
PublicationA method of estimation of a single balun S parameters based on the measured parameters of back-to-back configuration is presented in the paper. Proposed approach is to measure two back-to-back circuits: i) direct connection of baluns and ii) connection with additional transmission line segment between the baluns. Coupling effects in both circuits are calculated from full-wave simulations. Next they are applied to estimate the parameters...
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Uniwersalny system bezprzewodowy do monitorowania zagrożeń bezpieczeństwa
PublicationW artykule przedstawiono budowę i działanie bezprzewodowego systemu monitorowania zagrożeń bezpieczeństwa, opartego na koncepcji samoorganizującej się sieci uniwersalnych węzłów telekomunikacyjnych(UWT). Na wstępie opisano schemat funkcjonalny systemu, uwzględniając szczególnie wynikające z niego zadania oraz budowę UWT. Następnie na wybranym przykładzie scharakteryzowano pracę samoorganizującejsię sieci UWT - sieci ad-hoc. W końcowej...
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Boundary problems for fractional differential equations
PublicationIn this paper, the existence of solutions of fractional differential equations with nonlinear boundary conditions is investigated. The monotone iterative method combined with lower and upper solutions is applied. Fractional differential inequalities are also discussed. Two examples are added to illustrate the results.