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Search results for: KNOWLEDGE GRID
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The use of a 4 PB strain sweep fatigue test to evaluate characteristics of carbon grid reinforced asphalt beams
PublicationThe article presents research results concerning pre-bituminized carbon grids for asphalt pavement reinforcement, which are used to prevent cracking and crack reflection thus increasing bearing capacity and durability of pavement. Research program involved testing of large sized double-layer samples, both reinforced and unreinforced. The advantage of using a carbon grid was especially visible after crack initiation. The energy...
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Design and Evaluation of the Compact and Autonomous Energy Subsystem of a Wave Energy Converter
PublicationThis paper presents the results of the design process focused on the development of the energy subsystem (ES) of a wave energy converter (WEC). The ES is an important electrical part that significantly affects the energy reliability and energy efficiency of the entire WEC device. The designed ES was intended for compact WECs powering IoT network devices working in the distributed grid. The developed ES is an electronic circuit...
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Distributed System For Noise Threat Evaluation Based On Psychoacoustic Measurements
PublicationAn innovative system designed for the continuous monitoring of acoustic climate of urban areas was presentedin the paper. The assessment of environmental threats is performed using online data, acquired through a grid ofengineered monitoring stations collecting comprehensive information about the acoustic climate of urban areas.The grid of proposed devices provides valuable data for the purpose of long and short time acoustic climateanalysis....
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Techno-economic analysis of a hybrid energy system for electrification using an off-grid solar/biogas/battery system employing HOMER: A case study in Vietnam
PublicationThe electrification of off-grid /island villages is a critical step towards improving the techno-economic circumstances of rural regions and the overall general growth of the country. However, consistent supply from a single source is not possible in these areas. Thus, a hybrid renewable energy system performs better in these conditions. The research challenge now is to identify the optimal combinations of HRES from the available...
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A comprehensive review on economic, environmental impacts and future challenges for photovoltaic-based electric vehicle charging infrastructures
PublicationIn this paper, a comprehensive review of the impacts and imminent design challenges concerning such EV charging stations that are based on solar photovoltaic infrastructures is presented, which is based on state-of-the-art frameworks for PV-powered charging stations and the latest case studies. The main factors that are targeted in this review are the management of an EV charging system that is a composite of PV and public grid,...
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Wind Conditions in Urban Layout – Numerical and Experimental Research
PublicationThis paper presents research which compares the numerical and the experimental results for different cases of airflow around a few urban layouts. The study is concerned mostly with the analysis of parameters, such as pressure and velocity fields, which are essential in the building industry. Numerical simulations have been performed by the commercial software Fluent, with the use of a few different turbulence models, including...
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Acoustics - new services for urban planning, research and education
PublicationThe main purpose of the presented design is twofold, namely: providing detailed information about the noise threats that occur every day in city areas and preventing the noise induced hearing loss especially among young people. An experimental system designed for the continuous monitoring of the acoustic climate of urban areas was developed and implemented within the PLGrid Plus project. The assessment of environmental threats...
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Application of wireless communication to small WECS with induction generator
PublicationWind energy conversion systems (WECS) seem to be self-evident elements of the future smart grids. Among many generator types the squirrel cage induction generator (SCIG) characterizes robustness and low cost. A full-scale power converter can perform smooth grid connection over wide speed range of multiple-stage geared SCIG. Increasing number of sensors can improve the WECS control and diagnostics but increasing number of thin wires...
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Voltage Transients Transfer over Medium Voltage Instrument Transformers
PublicationThis paper presents voltage harmonic transfer accuracy problems through voltage transformers which are used in power quality monitoring systems in medium and high voltage grids. A simplified lumped parameters circuit model of the voltage transformer is proposed and verified by simulation and experimental investigations. A number voltage transformers typically used in medium voltage grid has been tested in the conducted disturbances...
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Measurements and visualization of sound field distribution around organ pipe
PublicationMeasurements and visualization of acoustic field around an organ pipe are presented. Sound intensity technique was applied for this purpose. Measurements were performed in free field. The organ pipe was activated with a constant air flow, produced by an external compressor, aimed at obtaining long-term steady state responses of generated acoustic signal. Sound energy distribution was measured in a defined fixed grid of points...
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Power Electronic Transformer For Smart Grid Application
PublicationIn this paper the control system of Power Electronic Transformer (PET) for the Smart Grid application is proposed. The structure of PET is based on two Cascaded H-bridge (CHB) converters. The electrical energy is transferred between converters using Dual-Active-Bridges (DAB) and high-frequency transformers. This type of coupling has been used to connect the DC-links of all H-bridges. The proposed control system for PET makes it...
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Measurement and visualization of sound intensity vector distribution in proximity of acoustic diffusers
PublicationIn this work, we would like to present analyses and visualizations of sound intensity distribution measured in proximity of an acoustic diffuser. Such distribution may be used for estimation of basic acoustic parameters of a diffuser. Measurement is performed with the use of a logarithmic sine sweep which allows for the analysis of waves scattered by the diffuser and rejecting the direct sound signal component. Pressure and sound...
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Reducing Air Pollutant Emissions from the Residential Sector by Switching to Alternative Energy Sources in Single-Family Homes
PublicationThe paper discusses a scenario for adapting residential buildings to the requirements of the EU climate and energy package. It analyzes the option of reducing pollutant emissions to ambient air by switching to alternative energy sources in a typical single-family residential building. The most common sources of energy in central heating and ventilation systems and water heating systems were compared, and the analyzed energy carriers...
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Electrical mapping of AISI 304 stainless steel subjected to intergranular corrosion performed by means of AFM-LIS in the contact mode
PublicationThe paper presents results of the AFM-based approach to local impedance spectroscopy (LIS) measurements performed in a 20 20 lm grid within an austenite grain–grain boundary region for sensitized AISI 304 stainless steel (SS). Maps of electrical parameters obtained on the basis of localized impedance spectra were demonstrated, presenting their changes and correlation with the sample topography. Performed research revealed significant...
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Inteligentne wspomaganie podejmowania decyzji z wykorzystaniem metod sztucznej inteligencji w środowisku obliczeniowym typu grid
PublicationPodejmowanie decyzji jest uważane za jedno z najbardziej krytycznych działań w organizacji. W celu wsparcia tego złożonego procesu dla osób odpowiedzialnych różne niezależne, samodzielne systemy wspomagania decyzji zostały opracowane głównie w ostatnich dwóch dekadach. Patrząc w sposób komplementarny na te systemy, wiążemy je z rolą i funkcją, którą musi spełniać z punktu widzenia użytkownika. W rozdziale opisano systemy wspomagania...
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Foundations of Grid Processing Architecture for the Comcute System
PublicationFundamental system algorithms and structures implemented in the Comcute system are described and analysed in detail. Layered architecture of the system model is highlighted. System tasks of the layers are elaborated, presented and described. Operational details of communication interfaces among layers are worked out and examined. The focus is put onto implemented system components with regard to their operability and efficiency....
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Imaging of Increasing Damage in Steel Plates Using Lamb Waves and Ultrasound Computed Tomography
PublicationThis paper concerns inspection of steel plates, with particular emphasis on the assessment of in-creasing damage. Non-destructive tests were performed on four plates, one of which was un-damaged, while the remaining three had a defects in the form of circular holes with a diameter of 2, 5, and 10 cm. Guided Lamb waves were used in the research, and the image reconstruction was performed using ultrasound computed tomography. The...
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Establishment of the Right of Electricity Transmission Easement Through Court Proceedings
PublicationIncluding the amendment of the Civil Code Act on May 30, 2008, issues related to the right of easement of transmission were introduced to it. Such a regulation was necessary in view of the need to define the legal status of transmission facilities, existing and designed on real estate property. The purpose of the study is to analyze issues related to the definition of the spatial extent of the law of transmission easement for power...
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Experimental research of the stability of steel cylindricalshell subjected to circumferential compression
PublicationAt the Department of Metal Structures Gdańsk University of Technology, experiments have been performed on the stability of shell of steel cylindrical models. The experiments have been carried on a test bench built at the Department. The design based on other test benches which were created in the past by other scientists, where modernized by the courtesy of companies that offer modern solutions. The test bench enables to generate...
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The Innovative Faculty for Innovative Technologies
PublicationA leaflet describing Faculty of Electronics, Telecommunications and Informatics, Gdańsk University of Technology. Multimedia Systems Department described laboratories and prototypes of: Auditory-visual attention stimulator, Automatic video event detection, Object re-identification application for multi-camera surveillance systems, Object Tracking and Automatic Master-Slave PTZ Camera Positioning System, Passive Acoustic Radar,...
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Conception and design of a hybrid exciter for brushless synchronous generator. Application for autonomous electrical power systems = Koncepcja i projekt hybrydowej wzbudnicy bezszczotkowego generatora synchronicznego. Zastosowanie w autonomicznych systemach elektroenergetycznych.
PublicationThis paper covers a subject of a hybrid excitation system for a brushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid). A hybrid excitation system (hybrid exciter) means a synchronous machine with wound-field and permanent magnet excitation. The hybrid exciter supply a dc field current to the synchronous generator field winding through a rotating rectifier....
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The finite-difference simulation of x-rays propagation through a system of lenses
PublicationThe propagation of X-ray waves through an optical system consisting of 33 aluminum X-ray refractive lenses is considered. For solving the problem, a finite-difference method is suggested and investigated. It is shown that very small steps of the difference grid are necessary for reliable computation of propagation of X-ray waves through the system of lenses. It is shown that the wave phase is a function very quickly increasing...
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Sound Field Intensity Measurements and Visualization around the Human Head Model . Rozkłąd natężenia pola akustycznego w komorze bezechowej obecności sztucznej głowy i w przypadku braku jej obecności
PublicationThe main goal of this research study was to measure and visualize sound field intensity distribution in and without presence of the human head model. Measurements were performed in the anechoic chamber with the 5 cm grid. Experimental setup consisted of a multitone generator, two loudspeakers, human head model, intensimetric probe, the Cartesian robot applied for precise positioning of the acoustic sensor, and an analyzer. Based...
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FDTD-Compatible Green's function based on scalar discrete Green's function and multidimensional Z-transform
PublicationIn this contribution, a new formulation of the discrete Green's function (DGF) is presented for the finitedifference time-domain (FDTD) grid. Recently, dyadic DGF has been derived from the impulse response of the discretized scalar wave equation (i.e., scalar DGF) with the use of the multidimensional Z-transform. Its software implementation is straightforward because only elementary functions are involved and a single function...
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Evolution of the HVDC Link Connecting Offshore Wind Farms to Onshore Power Systems
PublicationThis paper presents an overview of the DC link development and evolution dedicated to HVDC structure for connecting offshore wind power plants to onshore power systems. The growing demand for the green energy has forced investors in power industry to look for resources further out at sea. Hence, the development of power electronics and industrial engineering has enabled offshore wind farms to be situated further from the shore...
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Tracking Fluorescent Dye Dispersion from an Unmanned Aerial Vehicle
PublicationCommercial unmanned aerial vehicles continue to gain popularity and their use for collecting image data and recording new phenomena is becoming more frequent. This study presents an effective method for measuring the concentration of fluorescent dyes (fluorescein and Rhodamine WT) for the purpose of providing a mathematical dispersion model. Image data obtained using a typical visible-light camera was used to measure the concentration...
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Non-Salient Brushless Synchronous Generator Main Exciter Design for More Electric Aircraft
PublicationThis paper presents a prototype of high speed brushless synchronous generators (BSG) design for the application in autonomous electric power generation systems (e.g., airplane power grid). Commonly used salient pole field of the main generator part of BSG was replaced with a prototype non-salient pole field. The main objective of the research is an investigation into the advantages and disadvantages of a cylindrical field of the...
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Image Processing Techniques for Distributed Grid Applications
PublicationParallel approaches to 2D and 3D convolution processing of series of images have been presented. A distributed, practically oriented, 2D spatial convolution scheme has been elaborated and extended into the temporal domain. Complexity of the scheme has been determined and analysed with respect to coefficients in convolution kernels. Possibilities of parallelisation of the convolution operations have been analysed and the results...
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MODELOWANIE PROPAGACJI HAŁASU I JEGO WPŁYWU NA SŁUCH Z WYKORZYSTANIEM PLATFORMY OBLICZENIOWEJ PL GRID PLUS
PublicationW referacie przedstawiono usługi dostępne w gridzie dziedzinowym Akustyka, opracowane w ramach projektu PL Grid Plus. Przygotowane usługi umożliwiają modelowanie propagacji hałasu w środowisku aglomeracji miejskiej pochodzącego ze źródeł liniowych (drogi), punktowych lub powierzchniowych (hałas przemysłowy, imprezy plenerowe) z wykorzystaniem klastrów oblicze-niowych. Na podstawie uzyskanych wyników rozkładu poziomu hałasu możliwe...
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Dobór elementów instalacji fotowoltaicznych - instalacje on-grid
PublicationObecnie instalacje fotowoltaiczne dołączone do sieci stanowią 72% wszystkich systemów fotowoltaicznych.System PV podłączony do sieci elektroenergetycznej wytwarza energię, która jest w sposób ciągły przekazywana do sieci, co (przeciwnie niż w instalacjach off-grid) pozwala na całkowite niedopasowanie liczby zamontowanych w instalacji modułów fotowoltaicznych do zapotrzebowania obiektu na energię elektryczną. W efekcie instalacja...
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Parallel implementation of the DGF-FDTD method on GPU Using the CUDA technology
PublicationThe discrete Green's function (DGF) formulation of the finite-difference time-domain method (FDTD) is accelerated on a graphics processing unit (GPU) by means of the Compute Unified Device Architecture (CUDA) technology. In the developed implementation of the DGF-FDTD method, a new analytic expression for dyadic DGF derived based on scalar DGF is employed in computations. The DGF-FDTD method on GPU returns solutions that are compatible...
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Towards rainfall interception capacity estimation using ALS LiDAR data
PublicationIn this study we develop a spatial model for interception capacity of vegetation based on LiDAR data. The study is conducted in the natural wetland river valley dominated meadows, reeds and small bushes. The multiple regression model was chosen to relate the field measurements of interception capacity and LiDAR statistics at 2m grid. The optimal model was chosen by stepwise selection and further manual variables selection resulting...
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Modern technologies in energy demand reducing of public transport — Practical applications
PublicationCity of Gdynia (Poland) exploits one of the most modern trolleybus network in Europe, which has been involved in many projects related to the reduction of energy consumption. Some of them are connected with the improving of energy breaking recovery usage. An experimental stationary storage system at Północna substation, which was tested in 2012-2014, is a bright example of a system which is connected with the improving of the...
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Techno-economic assessment of cooperation of hybrid renewable energy sources with hydrogen storage
PublicationThe paper presents a technical and economic analysis of the power supply for a model industrial facility with the use of the most promising renewable energy sources (RES), supported by a hydrogen energy storage. This scenario was compared with the variants of supplying the facility directly from the grid and from RES without energy storage. A strategy was proposed for powering the plant aimed at maximising self-consumption of self-generated...
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Cost-Effective Piggyback Forward dc-dc Converter
PublicationThe novel piggyback dc-dc converter as a cost-effective solution is presented in this work. It provides a wide input voltage range of regulation with a low component count. The novel solution is an advanced forward dc-dc converter with an additional clamp output capacitor. The idea of such a type of converter is to transfer magnetizing energy of transformer to the output side, instead of using input clamp circuit. The design guidelines...
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Analytical Expression for the Time-Domain Discrete Green's Function of a Plane Wave Propagating in the 2-D FDTD Grid
PublicationIn this letter, a new closed-form expression for the time-domain discrete Green's function (DGF) of a plane wave propagating in the 2-D finite-difference time-domain (FDTD) grid is derived. For the sake of its verification, the time-domain implementation of the analytic field propagator (AFP) technique was developed for the plane wave injection in 2-D total-field/scattered-field (TFSF) FDTD simulations. Such an implementation of...
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Analysis of radiation and scattering problems with the use of hybrid techniques based on the discrete Green's function formulation of the FDTD method
PublicationIn this contribution, simulation scenarios are presented which take advantage of the hybrid techniques based on the discrete Green's function formulation of the finite-difference time-domain (DGF-FDTD) method. DGF-FDTD solutions are compatible with the finite-difference grid and can be applied for perfect hybridization of the FDTD method. The following techniques are considered: (i) DGF-FDTD for antenna simulations, (ii) DGF-based...
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Analytical Expression for the Time-Domain Green's Function of a Discrete Plane Wave Propagating in the 3-D FDTD Grid
PublicationIn this paper, a closed-form expression for the time-domain dyadic Green’s function of a discrete plane wave (DPW) propagating in a 3-D finite-difference time-domain (FDTD) grid is derived. In order to verify our findings, the time-domain implementation of the DPW-injection technique is developed with the use of the derived expression for 3-D total-field/scattered-field (TFSF) FDTD simulations. This implementation requires computations...
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LabVIEW-based intelligent system of protection against electric shock for photovoltaic installations
PublicationEvaluation of shock hazard in installations with photovoltaic sources of energy is more complicated than in a conventional low voltage system. In case of earth fault in photovoltaic generators, that are connected to the AC power public grid, a composite waveform of earth fault current in the installation may occur. For composite waveforms, the safety criteria should be modified. The paper considers the effect of the composite waveforms...
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Neural network model of ship magnetic signature for different measurement depths
PublicationThis paper presents the development of a model of a corvette-type ship’s magnetic signature using an artificial neural network (ANN). The capabilities of ANNs to learn complex relationships between the vessel’s characteristics and the magnetic field at different depths are proposed as an alternative to a multi-dipole model. A training dataset, consisting of signatures prepared in finite element method (FEM) environment Simulia...
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Numerical Issues and Approximated Models for the Diagnosis of Transmission Pipelines
PublicationThe chapter concerns numerical issues encountered when the pipeline flow process is modeled as a discrete-time state-space model. In particular, issues related to computational complexity and computability are discussed, i.e., simulation feasibility which is connected to the notions of singularity and stability of the model. These properties are critical if a diagnostic system is based on a discrete mathematical model of the flow...
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Photogrammetry image-based approach for imperfect structure modelling and FE analysis
PublicationThis study aims to model and analyse imperfect tructures using real measurements, employing photogrammetry technique commonly used in the geodesy. The study highlights the capability of the photogrammetry in aiding the structural analysis of imperfect engineering objects. Firstly, the photogrammetry measurements of a stiffened plate are carried out using a specially designed for the purpose experimental stand. Then, the plate surface...
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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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Interpolation methods in GPR tomographic imaging of linear and volume anomalies for cultural heritage diagnostics
PublicationThis paper presents results of a ground penetrating radar (GPR) survey conducted in St. Joseph’s Church in Gdańsk, Poland. The aim of the study was to produce tomographic imaging of a renovated floor as well as the objects buried under the floor to detect linear and volume inclusions. The assumed track spacing was meaningfully greater than the single signal spacing in each track, which induced the need for interpolation methods...
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Energy neutrality versus carbon footprint minimization in municipal wastewater treatment plants
PublicationThis work aimed to compare the carbon footprint (CF) of six full-scale wastewater treatment plants (WWTPs). The CF was estimated in the range of 23–100 kg CO2e per population equivalent. In the total CF, the direct emissions held the highest share (62–74%) for the plants with energy recovery from biogas. In the plants depending entirely on the power grid, the indirect emissions due to energy consumption dominated the total CF (69–72%)....
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The Influence of a Photovoltaic Micro-Installation on the Low-Frequency Parameters of Electricity at PCC and Its Impact on the Thermal Characteristics of Selected Devices
PublicationThis manuscript illustrates the measurement results of parameters describing the quality of energy at the PCC (point of common coupling) of a photovoltaic micro-installation that can significantly affect devices in the same power grid. The analyses reflecting heating of selected devices used in domestic installations, which were performed in an isolated laboratory environment, are also indicated. The conducted study aimed at checking...
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FEM modelling of stress and strain distribution in weld joints of steel sandwich panels
PublicationThe development of laser welding technology has enabled the mass production of thin-walled structures, including steel sandwich panels. The technology of joining plating panels with stiffeners by welding allows us to create joints with a specific geometry and material properties. In comparison with other types of joints, laser welds are characterized by their specific behaviour under cyclic load and, as a consequence, a different...
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A Wind Energy Conversion System Based on a Generator with Modulated Magnetic Flux
PublicationIn this work, the concept of an energy conversion system for wind turbines based on the modified permanent magnet synchronous generator (PMSG) is presented. In the generator, a pair of three-phase windings is used, one of which is connected in a “star” and the second in a “delta” configuration. At the outputs of both windings, two six-pulse uncontrolled (diode) rectifiers are included. These rectifiers are mutually coupled by a...
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Application of the discrete Green's function-based antenna simulations for excitation of the total-field/scattered-field interface in the FDTD method
PublicationIn this article, the discrete Green's function formulation of the finite-difference time-domain (DGF-FDTD) method is proposed for simulation of wire antennas irradiating inhomogeneous dielectric scatterers. Surface equivalence theorem in the discrete domain is used to separate the problem into an inhomogeneous domain and a wire antenna that are simulated with the use of FDTD and DGF-FDTD, respectively. Then, the excitation of the...
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Security Information Sharing for the Polish Power System
PublicationThe Polish Power System is becoming increasingly more dependent on Information and Communication Technologies which results in its exposure to cyberattacks, including the evolved and highly sophisticated threats such as Advanced Persistent Threats or Distributed Denial of Service attacks. The most exposed components are SCADA systems in substations and Distributed Control Systems in power plants. When addressing this situation...