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Search results for: ELECTROMAGNETIC%20CLOAKINGWAVE%20PROPAGATIONMAXWELL%E2%80%99S%20EQUATIONSFRACTIONAL%20CALCULUS
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Application of titanium dioxide thin films in fiber optic sensors
PublicationThe advance in the nanotechnology and fabrication of micro- and nanostructures has significant impact on development of new optical sensors. Presented study focuses on the applications of the titanium dioxide (TiO2) thin films in fiber optic sensors. The concept of a sensing fiber optic interferometer integrating TiO2 thin film is presented. The cavity of this interferometer is delimited by a 80 nm film fabricated on the end-face...
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5-Bromo-2′-deoxycytidine—a potential DNA photosensitizer
PublicationA double-stranded oligonucleotide, 80 base pairs in length, was multiply labeled with 5-bromo-2′-deoxycytidine (BrdC) using polymerase chain reaction (PCR). The modified oligonucleotide was irradiated with 300 nm photons and its damage was assayed by employing DHPLC, LC-MS and denaturing polyacrylamide gel electrophoresis (PAGE). Two types of damage were demonstrated, namely, single strand breaks (SSBs) and intrastrand cross-links...
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Artificial-Hand Technology—Current State of Knowledge in Designing and Forecasting Changes
PublicationThe subject of human-hand versatility has been intensively investigated for many years. Emerging robotic constructions change continuously in order to mimic natural mechanisms as accurately as possible. Such an attitude is motivated by the demand for humanoid robots with sophisticated end effectors and highly biomimic prostheses. This paper provides wide analysis of more than 80 devices that have been created over the last 40 years....
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X-Ray Diffraction, Mössbauer Spectroscopy and Magnetoelectric Effect Studies of Multiferroic Bi5Ti3FeO15 Ceramics
PublicationBi5Ti3FeO15 ceramics belongs to multiferroic class of materials. In this work it was prepared by solid-state sintering method and investigated by X-ray diffraction, Mössbauer spectroscopy, and magnetoelectric effect measurements. As it was proved by X-ray diffraction studies the single-phase Bi5Ti3FeO15 compound was obtained. The Mössbauer investigations revealed paramagnetic character of the compound at room temperature as well...
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DYNAMIC MECHANICAL BEHAVIOUR OF GFRP COMPOSITES WITH SiO2 NANO PARTICLES REINFORCED EPOXY MATRIX
PublicationDynamic mechanic (DMA) tests were performed to compare the mechanical behaviour of glass fibre reinforced epoxy laminate composites with SiO2 nanoparticle reinforced matrix. The selection of the most promising nanoparticle concentrations was considered in terms of elastic modulus and glass transition temperature. The reference specimens (0% nanoparticles) did not contain diluent accordingly the results do not allow the exact comparison...
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Optymalizacja dewulkanizacji ciągłej rozdrobnionych odpadów gumowych
PublicationDynamiczny rozwój przemysłu motoryzacyjnego, przyczynił się do powstania ogromnej ilości odpadów gumowych, z których aż 80% stanowią zużyte opony samochodowe. Wydanie aktów praw-nych nakładających na producentów obowiązku zagospodarowania zużytych opon z jednoczesnym zakazem ich składowania, sprawiło iż recykling materiałowy odpadów gumowych nabiera obecnie coraz większego znaczenia, stanowiąc alternatywę dla powszechnie stosowanego...
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Numerical modeling of exciton impact in two crystalographic phases of the organo-lead halide perovskite (CH3NH3PbI3) solar cell
PublicationTo improve the power conversion efficiency of solar cells based on organo–lead halide perovskites, a detailed understanding of the device physics is fundamental. Here, a computational analysis of excitons impact is reported for these types of photocell. Numerical calculations based on the model, which take into account electronic charge carriers (electrons and holes), excitons and ions, have been carried out. The role of excitons...
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Visible light activity and photoelectrochemical properties of nitrogen-doped TiO2.
PublicationFotokatalizatory TiO2 domieszkowane azotem zostały zsyntetyzowane z propanolanu tytanu (IV) lub chlorku tytanu (IV) i tiomocznika. Żółte proszki otrzymane po ogrzewaniu w temperaturach 400-600 st.C fotokatalizowały mineralizację 4-chlorofenolu w zakresie światła widzialnego (delta większe lub równe 455nm. W odróżnieniu od uprzednio opublikowanych wyników, zsyntetyzowane fotokatalizatory nie zawierały siarki, lecz zamiast tego azot...
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Global EM-Driven Optimization of Multi-Band Antennas Using Knowledge-Based Inverse Response-Feature Surrogates
PublicationElectromagnetic simulation tools have been playing an increasing role in the design of contemporary antenna structures. The employment of electromagnetic analysis ensures reliability of evaluating antenna characteristics but also incurs considerable computational expenses whenever massive simulations are involved (e.g., parametric optimization, uncertainty quantification). This high cost is the most serious bottleneck of simulation-driven...
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ANALIZA STANU TECHNICZNEGO RUROCIĄGÓW: WODY PRZeMYSŁOWEJ I SOLANKI
PublicationPracę wykonano na zlecenie Przedsiębiorstwa Badawczo-Wdrożeniowego "HYDRO-POMP" Sp. z o.o. ul. Wróblewskiego 19, 93-578 Łódź. Wykonawcą zlecenia jest Politechnika Gdańska, Wydział Chemiczny, Katedra Elektrochemii, Korozji i Inżynierii Materiałowej, 80-233 Gdańsk, ul. G. Narutowicza 11/12. Celem pracy była analiza stanu technicznego i badania dwóch rurociągów: solanki oraz wody przemysłowej. Badania wykonywano w warunkach terenowych...
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Kreatywna destrukcja uniwersytetu = Creative destruction of the university
PublicationAutorzy podejmują problematykę zmian we współczesnym uniwersytecie. Wychodząc z założenia, że celem uniwersytetu jest, obok kształcenia masowego, wykształcenie elity przedsiębiorców intelektualnych przyszłych liderów społeczeństwa wiedzy, zaproponowano twórczą destrukcję organizacji uczelni, której istotą jest przeniesienie osi organizacyjnej z podstawowych jednostek uczelni, jakimi są wydziały na zespoły, a osi koordynacyjnej...
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Reduced-cost constrained miniaturization of wideband antennas using improved trust-region gradient search with repair step
PublicationIn the letter, an improved algorithm for electromagnetic (EM)-driven size reduction of wideband antennas is proposed. Our methodology utilizes variable-fidelity EM simulation models, auxiliary polynomial regression surrogates, as well as multi-point response correction. The constraint handling is implicit, using penalty functions. The core optimization algorithm is a trust-region gradient search with a repair step added in order...
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Does the low optical band gap of yellow Bi3YO6 guarantee the photocatalytical activity under visible light illumination?
PublicationBi3YO6, which is known as an ionic conductor, was tested here as an electrode and photoanode in contact with aqueous electrolytes. Bi3YO6 was deposited onto the Pt substrate and the such prepared electrode was polarized in various aqueous electrolytes. The optical energy band gap of the material equal to 1.89 eV was determined using the Kubelka-Munk function resulting from the UV-Vis spectrum (allowed indirect transition) and also...
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Low-fidelity model considerations for simulation-based optimisation of miniaturised wideband antennas
PublicationHere, variable-fidelity electromagnetic (EM)-based design optimisation of miniaturised antennas is discussed. The authors focus on an appropriate selection of discretisation density of the low-fidelity EM model, which results in good performance of the optimisation algorithm in terms of its computational complexity and reliability. Trust-region gradient search with low-fidelity model corrected by means of non-linear frequency scaling...
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Conducted emi identification in power electronic converters : modeling of EMI generation and propagation using circuit simulation and wiener filtering methods.
PublicationThis work presents the circuit simulations and the conventional signal processing technique (Wiener filtering) in order to reconstruct conducted ElectroMagnetic Interferences (EMI), generated and propagated in power electronics converters. In the simulation study, the most accurate presently available models of components of circuit have been used and improved. The proposed Wiener filtering method allows to identifying the transfer...
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Filtrujące struktury ebg w układzie zasilania planarnej anteny szczelinowej
PublicationW pracy zaprezentowano koncepcję miniaturyzacji systemu nadawczo/odbiorczego polegającą na wprowadzeniu filtrujących struktur EBG (ang. Electromagnetic BandGap) w torze zasilania anteny, dzięki czemu możliwa jest eliminacja dodatkowego komponentu filtrującego. Rozważono szerokopasmową antenę szczelinową o konwencjonalnej topografii, którą następnie zmodyfikowano poprzez umieszczenie w układzie zasilania prostej, pasmowo-zaporowej...
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A subdomain model for armature reaction field and open‐circuit field prediction in consequent pole permanent magnet machines
PublicationIn this paper, the machine quantity, such as electromagnetic torque, self and mutual inductances, and electromotive force, is analytically calculated for non-overlapping winding consequent pole slotted machine for open-circuit field and armature reaction. The sub-domain approach of (2-D) analytical model is developed using Maxwell's equations and divide the problem into slots, slot-openings, airgap and magnets region, the magnet...
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Identification and non-integer order modelling of synchronous machines operating as generator
PublicationThis paper presents an original mathematical model of a synchronous generator using derivatives of fractional order. In contrast to classical models composed of a large number of R-L ladders, it comprises half-order impedances, which enable the accurate description of the electromagnetic induction phenomena in a wide frequency range, while minimizing the order and number of model parameters. The proposed model takes into account...
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Rapid Yield Estimation and Optimization of Microwave Structures Exploiting Feature-Based Statistical Analysis
PublicationIn this paper, we propose a simple, yet reliable methodology to expediteyield estimation and optimization of microwave structures. In our approach,the analysis of the entire response of the structure at hand (e.g., $S$-parameters asa function of frequency) is replaced by response surface modeling of suitablyselected feature points. On the one hand, this is sufficient to determinewhether a design satisfies given performance specifications....
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On low-fidelity models for variable-fidelity simulation-driven design optimization of compact wideband antennas
PublicationThe paper addresses simulation-driven design optimization of compact antennas involving variable-fidelity electromagnetic (EM) simulation models. Comprehensive investigations are carried out concerning selection of the coarse model discretization density. The effects of the low-fidelity model setup on the reliability and computational complexity of the optimization process are determined using a benchmark set of three ultra-wideband...
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Diagnostics of pillars in St. Mary’s Church (Gdańsk, Poland) using the GPR method
PublicationThe main goal of this study was non-destructive evaluation of pillars in the St. Mary’s Church (Gdańsk, Poland) using the ground penetrating radar (GPR) technique. The GPR inspection was conducted on four brick masonry pillars and five pillars strengthened by reinforced concrete jacketing. Data were acquired with a 2 GHz antenna along longitudinal and transverse profiles. The study involved the estimation of the electromagnetic...
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Non-isolated resonant quasi-Z-source network DC–DC converter
PublicationA novel non-isolated resonant quasi-impedance (quasi-Z)-source network DC–DC converter is proposed. The resonant impedance source network is derived from the quasi-Z-source network by including the autotransformer-based resonant cell instead of the second inductor of the quasi-Z-network. The leakage inductance of the autotransformer and two resonant capacitors connected in series with the autotransformer windings constitute a high-frequency...
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Thermal conductivity of M0-M100 specimens
Open Research DataThermal conductivity and volumetric heat capacity values of M0, M20, M40, M60, M80, M100 samples
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Thermogravimetric measurement (TG) of 20wt.% Ce0.8La0.2O2-NiO-YSZ anode for DIR-SOFC
Open Research DataThe daataset includes the thermogravimetric measurement (TG) of Ce0.8La0.2O2-NiO-YSZ anode for DIR-SOFC. The mesurement was performed under synthestic air atmosphere. The anode was composed of NiO-YSZ cermet composite (80 wt%) and Ce0.8La0.2O2-s additive (20wt%) with the addition of poroformer - PMMA granules 8um diameter (40 vol.% of whole powder volume)....
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The structure, including stereochemistry, of levorin A1
PublicationThe constitution and stereostructure of levorin A1 1, an aromatic heptaeneantifungal antibiotic, was established on the basis of NMR studies, which contained DQFCOSY,ROESY, HSQC and HMBC experiments. Mycosamine moiety was used as an internalchiral probe to determine the absolute configuration of levorin A1 stereogenic centers: 13S,15R, 17S, 18R, 19S, 21R. The relative configuration of the remaining stereogenic centers wasassigned...
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Comparative conformance cases for monitoring multiple implementations of critical requirements
PublicationThe paper presents the concept and the mechanism of comparative conformance cases which support conformance monitoring in situations where a standard or other set of requirements are being implemented at multiple sites. The mechanism is enabled by NOR-STA services which implement the TRUST-IT methodology and are deployed in the cloud in accordance with the SaaS model. In the paper we introduce the concept of comparative conformance...
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Rapid dimension scaling of triple-band antennas by means of inverse surrogate modeling
PublicationGeometry scaling of antennas, i.e., finding optimum dimensions of the structure for given operating conditions and material parameters is an important yet challenging problem. In this paper, we discuss fast dimension scaling of triple-band antennas with respect to operating frequencies. We adopt the inverse surrogate modeling approach where the surrogate model is a function of the three operating frequencies of the antenna and...
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Open porosity and oven-dry density of concretes containing magnetite aggregate (M0-M100) mixes
Open Research DataRaw data for determination of open porosity and oven-dry densities of concretes containing different amount of magnetite aggregate (M0-M100) mixes. Sample designation is related to the publication associated with dataset.
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The XRD diffraction patterns of Ce0.9M0.1O2 prepared using the reverse microemulsion method
Open Research DataThe dataset includes XRD patterns of Ce0.9M0.1O2 (where M=Mn, Fe, Co, Ni, Cu) nanopowders prepared using the reverse microemulsion method. The powders were precipitated from organic-based solution using tetramethylammonium hydroxide (TMAOH). After the precipitation, the sediment was centrifuged and rinsed with alcohol several times. Precursors powder...
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Removal efficiency of phenol by ozonation process with calcium peroxide from aqueous solutions
PublicationPhenol has been introduced as a priority pollutant by the US Environmental Protection Agency. Advanced oxidation processes (AOPs) are one of the most efcient methods for removal of non-degradable organic pollutants in aqueous solutions. The removal efciencies of phenol and COD under optimal conditions pH=3, phenol concentration=5 mg/L, CaO2 concentration=0.025 mg/L, temperature 25 °C, 1 g/min ozonation rate and contact time=90...
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WYBRANE ASPEKTY ZMĘCZENIOWYCH USZKODZEŃ OKRĘTOWYCH WAŁÓW NAPĘDOWYCH
PublicationProblem zmęczeniowego pękania konstrukcji okrętowych w sposób istotny dla eksploatacji tychże obiektów ujawnił się na przełomie lat 70. i 80. ubiegłego stulecia. Ponieważ pęknięcia zmęczeniowe dotyczą głównie kadłubów statków i są szczególnie dotkliwe dla dużych jednostek (zbiornikowców, masowców i kontenerowców), dlatego też cała uwaga towarzystw klasyfikacyjnych i biur projektowych skupia się głównie na tym aspekcie uszkodzeń...
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Sustainable energy system combined biogas-feedSolid Oxide Fuel Cell and Microalgae technology
PublicationIn the new frontier of energy and environmental safety, new efficient and clean safe energy conversion systems are required. In this sense, the present work is framed within the context of Circular Economy and proposes a multidisciplinary study for the development of more efficient, economically viable and non-polluting energy conversion systems, based on the synergetic combination of different technologies: fuel cells, biofuels,...
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Potential Application of Solar Energy Systems for Electrified Urban Transportation Systems
PublicationThe paper presents a novel approach toward the use of solar energy systems in public transportation. The concept of energy generation in PV systems for supplying a trolleybus transportation system is proposed for the city of Gdynia (Poland). The suggested way of energy production allows reducing the environmental harm impact of the municipal transportation system. Moreover, the proposed way of green energy use can be a more profitable...
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The mechanical properties and bactericidal degradation effectiveness of tannic acid-based thin films for wound care
PublicationThe surface area is the most important aspect when considering the interactions between a material and the surrounding environment. Chitosan (CTS) and tannic acid (TA) were previously successfully tested by us to obtain thin films to serve as wound dressings or food packaging materials. However, surface properties as well as the antimicrobial activity of the material were not considered. They are important if the material is likely...
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Structure and electrical properties of nitrided NbN-TiN sol-gel derived films
PublicationW pracy przedstawiono rezultaty badań struktury oraz właściwości elektrycznych warstw NbN-TiN (o różnym stosunku molowym NbN/TiN)otrzymanych w wyniku termicznego azotowania warstw tlenkowych otrzymanych metodą zol-żel. Badania struktury przeprowadzono metodami AFM, XRD oraz XPS. Wynika z nich, iż głównymi fazami w wartstwach są NbN i TiN o rozmiarach ziaren około 100 nm. Jednakże zaobserwowano również istnienie niewielkiej ilości...
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Składowanie odpadów promieniotwórczych w Polsce.
PublicationGospodarka odpadami promieniotwórczymi i wypalonym paliwem jest obecnie największym problemem związanym z energetyką jądrową. Do początku lat 80-tych olbrzymie ilości odpadów niskoaktywnych wrzucane były do mórz i oceanów, obecnie są przechowywane na składowiskach lub poddawane recyklingowi. Składowanie odpadów (szczególnie tych wysokoaktywnych) staje się nie tylko problemem obecnych, ale i przyszłych pokoleń. Niniejszy artykuł...
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UCIĄŻLIWOŚĆ ZAPACHOWA Z WYSYPISKA ŚMIECI MONITOROWANA ZA POMOCĄ RÓŻNYCH TYPÓW ELEKTRONICZNEGO NOSA
PublicationPrzedstawiono wyniki badań klasyfikacji próbek powietrza atmosferycznego pobranych wokół miejskiego wysypiska śmieci pod kątem uciążliwości zapachowej. Badania przeprowadzono przy pomocy prototypu elektronicznego nosa i komercyjnego elektronicznego nosa typu Fast/Flash GC - HERACLES II. Prototyp był wyposażony w zestaw sześciu półprzewodnikowych czujników firmy FIGARO. Klasyfikację próbek powietrza w zależności od kierunku pobrania...
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Automatic recognition of therapy progress among children with autism
PublicationThe article presents a research study on recognizing therapy progress among children with autism spectrum disorder. The progress is recognized on the basis of behavioural data gathered via five specially designed tablet games. Over 180 distinct parameters are calculated on the basis of raw data delivered via the game flow and tablet sensors - i.e. touch screen, accelerometer and gyroscope. The results obtained confirm the possibility...
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Determination of Odour Interactions of Three-Component Gas Mixtures Using an Electronic Nose
PublicationThe paper presents an application of an electronic nose prototype comprised of six TGS-type sensors and one PID-type sensor to identify odour interaction phenomena in odorous three-component mixtures. The investigation encompassed eight odorous mixtures—toluene-acetone-triethylamine and formaldehyde-butyric acid-pinene — characterized by different odour intensity and hedonic tone. A principal component regression (PCR) calibration...
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STANOWISKO DO POMIARU SZEROKOŚCI KRAWĘDZI NARTY
PublicationRegeneracja sprzętu narciarskiego zapewnia nie tylko niezapomniane doznania na stoku, ale przede wszystkim bezpieczeństwo. Serwisowanie nart, poza smarowaniem, to w głównej mierze ostrzenie krawędzi na specjalistycznych szlifierkach. Poprawne wykonanie tej usługi polega na naostrzeniu krawędzi przy jednoczesnej minimalizacji ilości zebranego z narty materiału, co nie jest prostym zadaniem, gdyż typowa szerokość krawędzi narty jest...
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ODOUR IMPACT OF MUNICIPAL LANDFILL MONITORED WITH ULTRA-FAST GAS CHROMATOGRAPHY = ODDZIAŁYWANIE ZAPACHOWE SKŁADOWISKA ODPADÓW KOMUNALNYCH MONITOROWANE ZA POMOCĄ ULTRA SZYBKIEJ CHROMATOGRAFII GAZOWEJ
PublicationPrzedstawiono wyniki badań klasyfikacji próbek powietrza atmosferycznego pobranych wokół miejskiego składowiska odpadów komunalnych w okresie zimowym i letnim pod kątem uciążliwości zapachowej. Badania przeprowadzono przy pomocy komercyjnego elektronicznego nosa typu Fast/Flash GC - HERACLES II. Klasyfikację próbek powietrza atmosferycznego pobranych z różnych kierunków względem wysypiska śmieci przeprowadzano przy użyciu dyskryminacyjnej...
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TOPOLOGICAL CLUES FOR PREDICTING OUTCOMES OF MULTIPLAYER ONLINE BATTLE ARENA GAMES
PublicationWith 27 million people playing League of Legends every day, e-sports became more and more important part of our everyday life. Rise of its popularity builds a demand for better understanding e-sports mechanics on a deeper level. In the article, we test a hypothesis that it is possible to predict an outcome of Multiplayer Online Battle Arena game based on topological clues only (such as area of polygon where vertices are players...
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Ochronić ląd.
PublicationArtykuł poświęcony jest metodom ochrony brzegów morskich. W pierwszej jego części omówiono przyczyny powodujące, że prawie 80% polskiego brzegu cofa się, przy czym tempo cofania się stopniowo rośnie. Opisano zalety i wady stosowanych w świecie metod ochrony brzegów wraz z uwzględnieniem współczesnych zaleceń projektowania ochrony brzegu, tj. możliwie jak najmniejszej ingerencji w środowisko naturalne. Na koniec w pracy pokazano,...
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Inline Waveguide Filter With Compact Frequency-Dependent Coupling Producing Two Additional Poles and Three Transmission Zeros
PublicationThis work reports a compact frequency-dependent coupling (FDC) structure introduced in a rectangular waveguide, which allows to generate two additional in-band transmission poles and three transmission zeros (TZs). This serves to increase the order/selectivity of the waveguide bandpass filter in a compact inline topology, thus without the need for any additional space/volume or cross coupling. The proposed FDC consists of a partial-height...
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Rapid design closure of linear microstrip antenna array apertures using response features
PublicationA simple yet reliable approach to a rapid design closure of linear antenna array apertures at the electromagnetic (EM)-simulation level is proposed. Our methodology exploits an underlying array factor (AF) model suitably corrected by means of characteristic points (angles and levels) of the radiation pattern of the EM model of the antenna array aperture. This conveniently allows for controlling both the side lobe levels...
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Expedited Design Closure of Antennas By Means Of Trust-Region-Based Adaptive Response Scaling
PublicationIn the letter, a reliable procedure for expedited design optimization of antenna structures by means of trust-region adaptive response scaling (TR-ARS) is proposed. The presented approach exploits two-level electromagnetic (EM) simulation models. A predicted high-fidelity model response is obtained by applying nonlinear frequency and amplitude correction to the low-fidelity model. The surrogate created this way is iteratively rebuilt...
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A Subspace-Splitting Moment-Matching Model-Order Reduction Technique for Fast Wideband FEM Simulations of Microwave Structures
PublicationThis article describes a novel model-order reduction (MOR) approach for efficient wide frequency band finite-element method (FEM) simulations of microwave components. It relies on the splitting of the system transfer function into two components: a singular one that accounts for the in-band system poles and a regular part that has no in-band poles. In order to perform this splitting during the reduction process, the projection...
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Rapid antenna design optimization using shape-preserving response prediction
PublicationAn approach to rapid optimization of antennas using the shape-preserving response-prediction (SPRP) technique and coarsediscretization electromagnetic (EM) simulations (as a low-fidelity model) is presented. SPRP allows us to estimate the response of the high-fidelity EM antenna model, e.g., its reflection coefficient versus frequency, using the properly selected set of so-called characteristic points of the low-fidelity model...
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Fast Design Optimization of Waveguide Filters Applying Shape Deformation Techniques
PublicationThis paper presents an efficient design of microwave filters by means of geometry optimization using shape deformation techniques. This design procedure allows for modelling complex 3D geometries which can be fabricated by additive manufacturing (AM). Shape deforming operations are based on radial basis function (RBF) interpolation and are integrated into an electromagnetic field simulator based on the 3D finiteelement method (FEM)....
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Temperature Sensors Based on Polymer Fiber Optic Interferometer
PublicationTemperature measurements are of great importance in many fields of human activities, including industry, technology, and science. For example, obtaining a certain temperature value or a sudden change in it can be the primary control marker of a chemical process. Fiber optic sensors have remarkable properties giving a broad range of applications. They enable continuous real-time temperature control in difficult-to-reach areas, in...