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Search results for: WIDE BAND ANTENNAS, COMPACT ANTENNAS, WIDE-SLOT ANTENNAS, EM-DRIVEN DESIGN, CIRCULARLY POLARIZED ANTENNA
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Resonant Frequencies in the Open Microstrip Structures Placed on Curved Surfaces
PublicationThe paper presents the research on open microstrip structures placed on curved surfaces such as cylindrical, elliptical or spherical. The numerical analysis of investigated structures is based on expansion of electric and magnetic fields into suitable function series. Utilizing the continuity conditions the boundary problem is formulated which is solved with the use of method of moments. The investigated structures find application...
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Performance Evaluation of GAM in Off-Body Path Loss Modelling for Body Area Networks
PublicationThis paper addresses the performance evaluation of an off-body path loss model, based on measurements at 2.45 GHz, which has been developed with the use of the Generalised Additive Model, allowing to model a non-linear dependence on different predictor variables. The model formulates path loss as a function of distance, antennas’ heights, antenna orientation angle and polarisation, results showing that performance is very sensitive...
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Capacity of Surface Production of Band Sawing in Manufacture of Oak Floor Upper Layers
PublicationThin lamellae, corresponding to the layer components of structural glued members, i.e., 2-ply or 3-ply glued flooring, can be manufactured in re-sawing operations of kiln-dried wood blocks or in wet technologies, which currently seem to be more common because of the shorter drying time. The re-sawing process in wet technology is conducted on dedicated thin-cutting band sawing machines with stellite-tipped band saws. The goal of...
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Miniaturization of ESPAR Antenna Using Low-Cost 3D Printing Process
PublicationIn this paper, the miniaturized electronically steerable parasitic array radiator (ESPAR) antenna is presented. The size reduction was obtained by embedding its active and passive elements in polylactic acid (PLA) plastic material commonly used in low-cost 3D printing. The influence of 3D printing process imperfections on the ESPAR antenna design is investigated and a simple yet effective method to...
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Nonreciprocity of a ferrite coupled microstrip-slot lines junction
PublicationW oparciu o wyniki modelowania numerycznego zbadano efekty niewzajemne występujące w strukturze sekcji sprzężonych poprzez warstwę ferrytu linii mikropaskowej i szczelinowej. Wykazano występowanie zjawiska periodycznej transformacji energii rodzaju mikropaskowego w rodzaj szczelinowy i odwrotnie.
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Compact and Integrated High-Power Pulse Generation and Forming System
PublicationThis paper presents comprehensive analytical, numerical and experimental research of the compact and integrated high-power pulse generation and forming system based on the flux compression generator and the electro-explosive forming fuse. The paper includes the analysis of the presented solution, starting from the individual components studies, i.e., the separate flux compression generator tests in field conditions and the forming...
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Scientific research in the Department of Machine Design and Automotive Engineering
PublicationShort descriptions of various research subjects taken up at the Department of Machine Design and Automotive Engineering are included in the paper. The subjects cover a wide range of bearing systems and tribology research and the research on tires and road surfaces. A third field of activity is biomedical engineering – with the attempts to improve methods of modelling biological materials in FEM calculations. The Department has...
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Diagnostics of thermal processes in antenna systems of broadcast stations
PublicationDiagnostics is an important element associated with the operation of a radio antenna systems, allowing earlier detection of potential damage. Thermography is one of the diagnostic tools, which allows for non-invasive assessment of technical condition. It brings together both financial savings associated with the removal of the damage and the potential effects caused by it. The article presents an example of using a thermal imaging...
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MATERIALS & DESIGN
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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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Dis/Trust and data-driven technologies
PublicationThis concept paper contextualises, defines, and systematises the concepts of trust and distrust (and their interrelations), providing a critical review of existing literature so as to identify gaps, disjuncture, and continuities in the use of these concepts across the social sciences and in the context of the consolidation of the digital society. Firstly, the development of the concept of trust is explored by looking at its use...
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Application of the IMO standard manoeuvres procedure for pod-driven ships
PublicationInternational Maritime Organisation (IMO) in the resolution MSC.137(76) Standards for Ship manoeuvrability presents the manoeuvring criteria that has to be satisfied by majority of seagoing ships. Together with the criteria, procedures for carrying out the manoeuvring tests are also presented. They however do not correspond directly to ships with non-conventional steering-propulsion devices, like pod drives. IMO is aware of this...
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APPLICATION OF VORTEX FLOW MODEL IN PROPELLER-STATOR SYSTEM DESIGN AND ANALYSIS
PublicationThe paper covers basics of the vortex model used for propeller-stator systems. The outline of the design algorithm is given and the results of its application are shown. The designed propeller-stator system was the subject of model tests run at the CTO model basin and cavitation tunnel. Stator’s influence on the delivered power required by the propeller and its revolution rate has been examined by conducting self-propulsion...
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A CMRC-based compact rat-race coupler with harmonic suppression
PublicationIn this paper, an eective miniaturization technique exploiting compact microstrip resonant cells has been discussed and experimentally validated on the basis of a 3-dB microstrip rat-race coupler. The application of the method proposed has resulted in 91 % circuit area reduction in comparison to a conventional rat-race coupler. Experimental results show good agreement with theoretical characteristics, as well as an additional eect,...
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Role of nitrogen in optical and electrical band gaps of hydrogenated/hydrogen free carbon nitride film
PublicationWe report the optical and electrical band gap energy of amorphous hydrogenated carbon nitride (a-HCNx) and carbon nitride (a-CNx) as a function of nitrogen concentration (N/C). The optical band gap of a-HCNx and a-CNx films has been determined by means of Ellipsometry and UV-VIS. Both optical and electrical band gaps increase with elevated nitrogen concentration. Experimentally obtained electrical band gap is compared with the...
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Iridium 5d -electron driven superconductivity in ThIr3
PublicationA polycrystalline sample of superconducting ThI r 3 was obtained by arc-melting Th and Ir metals. Powder x-ray diffraction revealed that the compound crystalizes in a rhombohedral crystal structure (R-3m, s.g. #166) with the lattice parameters: a = 5.3394 ( 1 ) Å and c = 26.4228 ( 8 ) Å . Normal and superconducting states were studied by magnetic susceptibility, electrical resistivity, and heat capacity measurements. The results...
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Seminarium dyplomowe [EM] [2021/22]
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Wielkie Korki z WRS-em
e-Learning Courses -
A Cross-Polarisation Discrimination Analysis of Off-Body Channels in Passenger Ferryboat Environments
PublicationThere is a need for investigating radio channels for Body Area Networks considering the depolarisation phenomenon and new types of environments, since these aspects are becoming very important for systems design and deployment. This paper presents an analysis of cross-polarisation discrimination for off-body channels based on a measurement campaign performed in a passenger ferryboat, i.e., where all walls, floors and ceilings are...
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A Model-Driven Solution for Development of Multimedia Stream Processing Applications
PublicationThis paper presents results of action research related to model-driven solutions in the area of multimedia stream processing. The practical problem to be solved was the need to support application developers who make their multimedia stream processing applications in a supercomputer environment. The solution consists of a domain-specific visual language for composing complex services from simple services called Multimedia Stream...
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Polarized light pulses propagation and coupling in optical waveguides
PublicationGłównym celem tej pracy było zbudowanie modelu teoretycznego, na bazie równań Maxwella, który pozwoliłby na opis transmisji wielomodowej w falowodach dielektrycznych (światłowodach) z uwzględnieniem efektu nieliniowego typu Kerra. W pracy wyniki teoretyczne zostały porównane z wynikami doświadczalnymi. Do symulacji propagacji światła z uwzględnieniem efektu Kerra niezbędne było rozwiązanie sprzężonych nieliniowych równań Schrödingera...
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Education programmes as an element of limiting space and social barriers.CTA Home : Accessible Transportation : TRANSED 2007 [online]. [dostęp 2007.12.31]. Dostępny w World Wide Web: http: //www.tc.gca.ca - TRANSED 2007 COMOTRED
PublicationThe article presents education programme " Creating common space" introduced by Gdansk University of Technology - Architecture Department ( Poland) and local authorities. It also contains workshops " Cities without barriers" carried out in Pomeranian cities, where students are taught an additional subject " Designing common space". Liquidation of space barriers is necessary to help the disabled live their lives, develop and become...
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Em Questao
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A novel microstrip dual-layer rat-race coupler with compact size and enhanced bandwidth
PublicationMicrowave hybrid couplers are crucial components of mixers, phase shifters, amplifiers and other high-frequency systems. Conventional couplers are characterized by large size which limits their usefulness in modern applications. In this work, a novel compact rat-race coupler with enhanced bandwidth has been proposed. The structure consists of six compact microstrip resonant cells. It is implemented on two separate layers which permits...
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Prediction of manoeuvring abilities of 10000 DWT pod-driven coastal tanker
PublicationThis 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...
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Channel Impulse Response Measurements at mmWave Band in Office and Conference Rooms
PublicationIn this paper, the measurements of the channel impulse response at mmWave band in office and conference rooms are described. The central frequency is 27 GHz with a bandwidth of 400 MHz. The description of the used measurement stand and considered environments are presented. The initial analysis of the power delay profile, mean delay, and RMS delay spread allows preliminary conclusions to be drawn that there is a significant impact...
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On the low-cost design of abbreviated multisection planar matching transformer
PublicationA numerically demanding wideband matching transformer composed of three nonuniform transmission lines (NUTLs) has been designed and optimized at a low computational cost. The computational feasibility of the design has been acquired through the exploitation of low-fidelity NUTL models in most steps of the design procedure and an implicit space mapping optimization engine, providing high accuracy results with only a handful of EM...
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Simulation and experiment of radiating slot in a ground-plane of microstrip junction
PublicationW pracy przedstawiono badania numeryczne oraz eksperymentalne szczeliny promieniującej umieszczonej w płaszczyźnie masy złącza mikropaskowego. Złącze mikropaskowe składa się z linii mikropaskowej oraz rozwartego na końcu sęka. Szczelina umieszczona jest równolegle do linii mikropaskowej.
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Bayesian Optimization for solving high-frequency passive component design problems
PublicationIn this paper, the performance of the Bayesian Optimization (BO) technique applied to various problems of microwave engineering is studied. Bayesian optimization is a novel, non-deterministic, global optimization scheme that uses machine learning to solve complex optimization problems. However, each new optimization scheme needs to be evaluated to find its best application niche, as there is no universal technique that suits all...
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Parallel Implementation of the Discrete Green's Function Formulation of the FDTD Method on a Multicore Central Processing Unit
PublicationParallel implementation of the discrete Green's function formulation of the finite-difference time-domain (DGF-FDTD) method was developed on a multicore central processing unit. DGF-FDTD avoids computations of the electromagnetic field in free-space cells and does not require domain termination by absorbing boundary conditions. Computed DGF-FDTD solutions are compatible with the FDTD grid enabling the perfect hybridization of FDTD...
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Influence of ESPAR Antenna Radiation Patterns Shape on PPCC-Based DoA Estimation Accuracy
PublicationIn 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...
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Design of a microrobotic wrist for needle laparoscopic surgery
PublicationThe 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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A study of a compact high-efficiency zero-emission power plant with oxy-fuel combustion
PublicationThis paper discusses the application of global trends in gas cycles technology using oxy-fuel combustion. This is followed by a demonstration of a design solution for a new cycle with two enhanced energy-converting devices, namely a wet combustion chamber and a spray-ejector condenser. The proposed gas and steam cycle unit is contained within a single turbine, whose benefits combine those offered by gas turbines (high inlet temperatures)...
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Microfluidically Frequency-Reconfigurable Self-Quadruplexing Antenna Based on Substrate Integrated Square-Cavity
PublicationIn this article, a novel concept of self-quadruplexing tunable antenna (SQTA) enabled by microfluidic channels is investigated. The operating channels are either filled with air or dielectric liquids to enable frequency tunability. The proposed SQTA is implemented on the substrate-integrated square-cavity (SISC). A swastika-shaped slot is milled on the top-surface of the SISC to create four quarter-mode resonators. The resonators...
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Cost-Efficient Surrogate Modeling of High-Frequency Structures Using Nested Kriging with Automated Adjustment of Model Domain Lateral Dimensions
PublicationSurrogate models are becoming popular tools of choice in mitigating issues related to the excessive cost of electromagnetic (EM)-driven design of high-frequency structures. Among available techniques, approximation modeling is by far the most popular due to its versatility. In particular, the surrogates are exclusively based on the sampled simulation data with no need to involve engineering insight or problem-specific knowledge....
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A Study of Mutual Coupling Suppression between Two Closely Spaced Planar Monopole Antenna Elements for 5G New Radio Massive MIMO System Applications
Publication5G NR (new radio) introduces the concept of massive MIMO (multiple-input-multiple-output) technology, in which a larger number of antenna arrays are installed on the transceiver. Due to the increased number of antenna elements allocated close to each other (approximately at half-wavelength distance), mutual coupling becomes a serious problem leading to performance degradation of the MIMO communication system. In this communication,...
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Piotr Lorens prof. dr hab. inż. arch.
PeopleProf. Piotr Lorens - PhD, DSc., urban planner. Lecturer in urban design and development and - since 2007 - Head of the Department of Urban Design and Regional Planning at the Faculty of Architecture, Gdansk University of Technology. His university activities also include coordination of the research and EU Social Fund projects. Based on these projects he was responsible for organization and coordination of the post-graduate studies...
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Frequency-dependent coupling model for microwave band-pass filter
PublicationThe goal of this work was to create a circuit model which represents frequency-dependent coupling between microwave resonators. Our models are designed for in-line filters. The frequency-dependent coupling enables one to realize a transmission zero which is not possible in classical approach with frequency independent inverters. In addition, the proposed model allows us to observe out-of-band behavior, e.g. spurious resonance....
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Effects of Bromine Doping on the Structural Properties and Band Gap of CH3NH3Pb(I1–xBrx)3 Perovskite
PublicationAn experimental and theoretical study is reported to investigate the influence of bromine doping on CH3NH3Pb(I1−xBrx)3 perovskite for Br compositions ranging from x = 0 to x = 0.1, in which the material remains in the tetragonal phase. The experimental band gap is deduced from UV−vis absorption spectroscopy and displays a linear behavior as a function of bromine concentration. Density functional theory calculations are performed...
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FIR Filter Design Using Distributed Maximal Flatness Method
PublicationIn the paper a novel method for filter design based on the distributed maximal flatness method is presented. The proposed approach is based on the method used to design the most common FIR fractional delay filter - the maximally flat filter. The MF filter demonstrates excellent performance but only in a relatively narrow frequency range around zero frequency but its magnitude response is no greater than one. This ,,passiveness”...
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Role of nitrogen in evolution of sp2/sp3 bonding and optical band gap in hydrogenated carbon nitride
PublicationDrastic changes in the bonding are found in amorphous hydrogenated carbon nitride (a-CNx:H) film as a function of nitrogen concentration (or N/C ratio). The total C-sp3 fraction and hardness shows a sharp decrease (at N/C = 0.40) whereas optical band gap and resistivity shows a gradual increase as nitrogen concentration increases from 0.07 to 0.58. Raman spectrum of a-CNx:H film is fitted with both Gaussian (integrated intensity...
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Metamaterial-Based Series-Fed Antenna with High Gain and Wideband Performance for Millimeter Wave Spectrum Applications
PublicationThis paper presents a high-gain, wideband series-fed antenna designed for 5G millimeter-wave (MMW) applications. The structure employs a substrate-integrated waveguide (SIW)-based power splitter and metamaterials (MMs). The power divider functions effectively at 27.5 GHz, exhibiting an impedance bandwidth from 26.9–28.6 GHz. The series-fed dipole is assembled on the SIW-based power splitter, incorporating four dipoles with varying...
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Frequency Selective Surface Based MIMO Antenna Array for 5G Millimeter-Wave Applications
PublicationAbstract: In this paper a radiating element consisting of a modified circular patch is proposed for MIMO arrays for 5G millimeter-wave applications. The radiating elements in the proposed 2×2 MIMO antenna array are orthogonally configured relative to each other to mitigate mutual coupling that would otherwise degrade the performance of the MIMO system. The MIMO array was fabri-cated on Rogers RT/Duroid high frequency substrate...
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Compact broadband multi-way 1:6 power divider
PublicationThis paper introduces a design flow of a microstrip multi-way 1:6 power divider incorporating photonic bandgap (PBG) structures. Themethod proposed has enabled the achievement of considerable miniaturization (15%) together with transmission characteristics enhancement(141% bandwidth). Measured results show significant similarity to theoretical characteristics, which proves the attractiveness of presented design methodology.
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A strong preference for the TA/TA dinucleotide step discovered for an acridine-based, potent antitumor dsDNA intercalator, C-1305: NMR-driven structural and sequence-specificity studies
PublicationTriazoloacridinone C-1305, a potent antitumor agent recommended for Phase I clinical trials, exhibits high activity towards a wide range of experimental colon carcinomas, in many cases associated with complete tumor regression. C-1305 is a well-established dsDNA intercalator, yet no information on its mode of binding into DNA is available to date. Herein, we present the NMR-driven and MD-refined reconstruction of the 3D structures...
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Theory of architectural design V. Design for all
e-Learning CoursesThe aim of the course is to increase awareness of the needs of people with special needs and the idea of universal design. The subject is to introduce the social and legal conditions of the profession of architect, focused on the needs of all vulnerable user groups, including people with disabilities and the elderly. Knowledge of solutions related to Design for All is necessary due to the implementation of directives and standards...
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WORLD WIDE WEB-INTERNET AND WEB INFORMATION SYSTEMS
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Slot harmonics in cage motors due to saturation of a main magnetic circuit
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Rapid Microwave Design Optimization in Frequency Domain Using Adaptive Response Scaling
PublicationIn this paper, a novel methodology for cost-efficient microwave design optimization in the frequency domain is proposed. Our technique, referred to as adaptive response scaling (ARS), has been developed for constructing a fast replacement model (surrogate) of the high-fidelity electromagnetic-simulated model of the microwave structure under design using its equivalent circuit (low-fidelity model). The basic principle of ARS is...
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Global Complex Roots and Poles Finding Algorithm Based on Phase Analysis for Propagation and Radiation Problems
PublicationA flexible and effective algorithm for complex roots and poles finding is presented. A wide class of analytic functions can be analyzed, and any arbitrarily shaped search region can be considered. The method is very simple and intuitive. It is based on sampling a function at the nodes of a regular mesh, and on the analysis of the function phase. As a result, a set of candidate regions is created and then the roots/poles are verified...