Search results for: COMPUTER-AIDED ANTENNA DESIGN
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Introductory CDIO Project 2022/2023
e-Learning CoursesThe aim of this course is to make the students familiar with the team work to design, build and test simple electronic circuit. Also, how to write technical and engineering documentation taking in consideration electrical engineering, electronics, CAD and PCB design and computer simulation problems.
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Introductory CDIO Project [Energy Technologies][2020/21]
e-Learning CoursesThe aim of this course is to make the students familiar with the team work to design, build and test simple electronic circuit. Also, how to write technical and engineering documentation taking in consideration electrical engineering, electronics, CAD and PCB design and computer simulation problems.
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Introductory CDIO Project 2023/2024
e-Learning CoursesThe aim of this course is to make the students familiar with the team work to design, build and test simple electronic circuit. Also, how to write technical and engineering documentation taking in consideration electrical engineering, electronics, CAD and PCB design and computer simulation problems.
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Expedited antenna optimization with numerical derivatives and gradient change tracking
PublicationDesign automation has been playing an increasing role in the development of novel antenna structures for various applications. One of its aspects is electromagnetic (EM)-driven design closure, typically applied upon establishing the antenna topology, and aiming at adjustment of geometry parameters to boost the performance figures as much as possible. Parametric optimization is often realized using local methods given usually reasonable...
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Pareto Ranking Bisection Algorithm for EM-Driven Multi-Objective Design of Antennas in Highly-Dimensional Parameter Spaces
PublicationA deterministic technique for fast surrogate-assisted multi-objective design optimization of antennas in highly-dimensional parameters spaces has been discussed. In this two-stage approach, the initial approximation of the Pareto set representing the best compromise between conflicting objectives is obtained using a bisection algorithm which finds new Pareto-optimal designs by dividing the line segments interconnecting previously...
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Control System Design for Dynamic Positioning using Vectorial Backstepping
PublicationThe problem of synthesis a dynamic positioning system for low frequency model of surface vessel was considered in this paper. The recursive vectorial backstepping control design was used to keep a fixed position and heading in presence of wave disturbances. The passive observer was introduced to smooth the measurements and to estimate the velocities needed for the control algorithm. The computer simulation results were given to...
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NEW SOLUTIONS FOR THE SOLAR CHARGE CONTROLLERS DESIGN FOR OBTAINING TRUE MPP IN PARTLY SHADED PV MODULES
PublicationSoft shading sources such as tree limbs, structural elements of buildings and chimneys, scatter and refract sunlight, significantly reducing the amount of radiation reaching the surface of the module. The hard shadings located directly on the surface (i.e. bird droppings, leaves, snow) tend to stop sunlight completely. These phenomena significantly affects the output characteristics of photovoltaic modules and often contribute...
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Rapid Design Centering of Multi-Band Antennas Using Knowledge-Based Inverse Models and Response Features
PublicationAccounting for manufacturing tolerances as well as uncertainties concerning operating conditions and material parameters is one of the important yet often neglected aspects of antenna development. Appropriate quantification of uncertainties allows for estimating the fabrication yield but also to carry out robust design (e.g., yield maximization). For reliability reasons, statistical analysis should be executed at the accuracy level...
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Surrogate Modeling and Optimization Using Shape-Preserving Response Prediction: A Review
PublicationComputer simulation models are ubiquitous in modern engineering design. In many cases, they are the only way to evaluate a given design with sufficient fidelity. Unfortunately, an added computa-tional expense is associated with higher fidelity models. Moreover, the systems being considered are often highly nonlinear and may feature a large number of designable parameters. Therefore, it may be impractical to solve the design problem...
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Expedited Gradient-Based Design Closure of Antennas Using Variable-Resolution Simulations and Sparse Sensitivity Updates
PublicationNumerical optimization has been playing an increasingly important role in the design of contemporary antenna systems. Due to the shortage of design-ready theoretical models, optimization is mainly based on electromagnetic (EM) analysis, which tends to be costly. Numerous techniques have evolved to abate this cost, including surrogate-assisted frameworks for global optimization, or sparse sensitivity updates for speeding up local...
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Instrument detection and pose estimation with rigid part mixtures model in video-assisted surgeries
PublicationLocalizing instrument parts in video-assisted surgeries is an attractive and open computer vision problem. A working algorithm would immediately find applications in computer-aided interventions in the operating theater. Knowing the location of tool parts could help virtually augment visual faculty of surgeons, assess skills of novice surgeons, and increase autonomy of surgical robots. A surgical tool varies in appearance due to...
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Anti-theft lab security system based on RFID
PublicationThe aim of the project is to design and create an electronic system, which can be used to protect laboratory equipment against theft. The main task of the system is to warn a person responsible for the facilities about any attempts made to steal equipment from a laboratory. In a case of an alarm situation, the system emits a sound signal. The concept of the anti-theft security system based on RFID was developed on the basis of...
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Local mesh morphing technique for parametrized macromodels in the finite element method
PublicationThis paper presents a novel approach for enhancing the efficiency of the design process of microwave devices by means of the finite element method. It combines mesh morphing with local model order reduction (MOR) and yields parametrized macromodels that can be used to significantly reduce the number of variables in the FEM system of equations and acceleration of computer simulation. A projection basis for local reduction is generated...
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Reliable data-driven modeling of high-frequency structures by means of nested kriging with enhanced design of experiments
PublicationData-driven (or approximation) surrogate models have been gaining popularity in many areas of engineering and science, including high-frequency electronics. They are attractive as a way of alleviating the difficulties pertinent to high computational cost of evaluating full-wave electromagnetic (EM) simulation models of microwave, antenna, and integrated photonic components and devices. Carrying out design tasks that involve massive...
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Patryk Ziółkowski dr inż.
PeoplePatryk Ziolkowski is a graduate of the Faculty of Civil and Environmental Engineering at the Gdansk University of Technology, specializing in Building and Engineering Structures. He works as an Assistant Professor at the Department of Engineering Structures. He participated in international projects, including projects for the Ministry of Transportation of the State of Alabama (2015), he is also the winner of a grant from the Kosciuszko...
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Accelerated Gradient-Based Optimization of Antenna Structures Using Multi-Fidelity Simulations and Convergence-Based Model Management Scheme
PublicationThe importance of numerical optimization has been steadily growing in the design of contemporary antenna structures. The primary reason is the increasing complexity of antenna topologies, [ a typically large number of adjustable parameters that have to be simultaneously tuned. Design closure is no longer possible using traditional methods, including theoretical models or supervised parameter sweeping. To ensure reliability, optimization...
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Linux scheduler improvement for time demanding network applications, running on Communication Platform Systems
PublicationCommunication Platform Systems as ex. ATCA standard blades located in standardized chassis provides high level communication services between system peripherals. Each ATCA blade brings dedicated functionality to the system but can as well exist as separated host responsible for servicing set of task. According to platform philosophy these parts of system can be quite independent against another solutions provided by competitors....
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Artificial intelligence in architectural education - green campus development research
PublicationThe rapid advancement of artificial intelligence (AI) technologies has introduced new possibilities and challenges in design education. This article explores the need for changes and adaptations in the teaching process of design as AI-related technologies, based on image generation, transform the creative process and offer novel opportunities. In a research-by-design studio in an architectural faculty in Poland, students who utilised...
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Assessment of student language skills in an e-learning environment
PublicationThis article presents the role of various assessment structures that can be used in a VLE. e-Learning language courses offer tutors a wide range of traditional and computer-generated formative and summative assessment procedures and tools. They help to evaluate each student’s progress, monitor their activities and provide varied support, which comes from the tutor, the course structure and materials as well as other participants....
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Numerical Model of Surface and Quasi-Spherical Sea Noise and Its Application to Analysis of DIFAR Systems
PublicationVarious types of passive sonar systems are used to detect submarines. These activities are complex and demanding. Therefore, computer simulations are most often used at the design stage of these systems. For this reason, it is also necessary to simulate the acoustic ambient noise of the sea. The article proposes a new numerical model of surface and quasi-spherical sea noise and presents its statistical parameters. The results of...
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Multi Queue Approach for Network Services Implemented for Multi Core CPUs
PublicationMultiple core processors have already became the dominant design for general purpose CPUs. Incarnations of this technology are present in solutions dedicated to such areas like computer graphics, signal processing and also computer networking. Since the key functionality of network core components is fast package servicing, multicore technology, due to multi tasking ability, seems useful to support packet processing. Dedicated...
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Data-Driven Surrogate-Assisted Optimization of Metamaterial-Based Filtenna Using Deep Learning
PublicationIn this work, a computationally efficient method based on data driven surrogate models is pro-posed for the design optimization procedure of a Frequency Selective Surface (FSS)-based filtering antenna (Filtenna). A Filtenna acts as a as module that simultaneously pre-filters unwanted sig-nals, and enhances the desired signals at the operating frequency. However, due to a typically large number of design variables of FSS unit elements,...
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Linking music data in executable documents
PublicationThis paper presents the application of Interactive Open Document Architecture (IODA) to music and video data. This architecture was design to create multilayer documents which consist of many files. The paper shows the method of creating media documents on the basis of IODA. These kind of documents were called IODA Media Documents (IMD). IMD have links that connect many different kinds of files containing music and video data....
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Discussion on “Dynamic soil-structure interaction: A three-dimensional numerical approach and its application to the Lotung case study”. Poor performance of the HSS model
PublicationThe Hardening Soil Small (HSS) is a constitutive model being extension to the well established Hardening Soil Model (HS) accounting for the nonlinearity of small strain stiffness. It is implemented in commercial finite element computer codes for geotechnical analyses and used widely in research and design. The article deals with a problem known as overshooting after very small load reversals. It induces much higher stiffness than...
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On Computationally-Efficient Reference Design Acquisition for Reduced-Cost Constrained Modeling and Re-Design of Compact Microwave Passives
PublicationFull-wave electromagnetic (EM) analysis has been playing a major role in the design of microwave components for the last few decades. In particular, EM tools allow for accurate evaluation of electrical performance of miniaturized structures where strong cross-coupling effects cannot be adequately quantified using equivalent network models. However, EM-based design procedures (parametric optimization, statistical analysis) generate...
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Step on It Bringing Fullwave Finite-Element Microwave Filter Design up to Speed
PublicationThere are many steps in the design of a microwave filter: mathematically describing the filter characteristics, representing the circuit as a network of lumped elements or as a coupling matrix, implementing the distributed elements, finding the initial dimensions of the physical structure, and carrying out numerical tuning using electromagnetic (EM) simulators. The whole process is painstaking and time-consuming, and it requires...
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Topological modifications for performance improvement and size reduction of wideband antenna structures
PublicationCompact antennas belong to the key components of modern communication systems. Their miniaturization is often achieved by introducing appropriate topological changes such as simple ground plane slots or tapered feeds. More sophisticated modifications are rarely considered in the literature because they normally lead to significant increase of the number of tunable parameters, which makes the antenna design process more challenging....
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Performance-Driven Surrogate Modeling of High-Frequency Structures
PublicationThe development of modern high-frequency structures, including microwave and antenna components, heavily relies on full-wave electromagnetic (EM) simulation models. Notwithstanding, EM-driven design entails considerable computational expenses. This is especially troublesome when solving tasks that require massive EM analyzes, parametric optimization and uncertainty quantification be-ing representative examples. The employment of...
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Reduced-Cost Two-Level Surrogate Antenna Modeling using Domain Confinement and Response Features
PublicationElectromagnetic (EM) simulation tools have become indispensable in the design of contemporary antennas. Still, the major setback of EM-driven design is the associated computational overhead. This is because a single full-wave simulation may take from dozens of seconds up to several hours, thus, the cost of solving design tasks that involve multiple EM analyses may turn unmanageable. This is where faster system representations (surrogates)...
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Optimal selection of input features and an acompanying neural network structure for the classification purposes - skin lesions case study
PublicationMalignant melanomas are the most deadly type of skin cancers however detected early enough give a high chances for successful treatment. The last years saw the dynamic growth of interest of automatic computer-aided skin cancer diagnosis. Every month brings new research results on new approaches to this problem, new methods of preprocessing, new classifiers, new ideas to follow etc. In particular, the rapid development of dermatoscopy,...
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A technique of experiment aided virtual prototyping to obtain the best spindle speed during face milling of large-size structures
PublicationThe paper presents an original method concerning vibration suppression problem during milling of large-size and geometrically complicated workpieces with the use of novel way of selecting the spindle speed. This consists in repetitive simulations of the cutting process for subsequent values of the spindle speed, until the best vibration state of the workpiece is reached. An appropriate method of obtaining a computational model,...
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3D Computer Model of the Hip Joint Cartilage
PublicationThis paper presents 3D computer model of the hip joint cartilage in the ANSYS program. Model is made on the basis of anatomy and collected data on the material constants of bone and cartilage components. Analysis and comparison of biochemical model, viscoelastic and molecular mixed - aggregation serves to facilitate the creation of the next model of reality, which could be used in the design of joint prostheses. The correctness...
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Genetic Programming for Interaction Efficient Supporting in Volunteer Computing Systems
PublicationVolunteer computing systems provide a middleware for interaction between project owners and great number volunteers. In this chapter, a genetic programming paradigm has been proposed to a multi-objective scheduler design for efficient using some resources of volunteer computers via the web. In a studied problem, genetic scheduler can optimize both a workload of a bottleneck computer and cost of system. Genetic programming has been...
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A new approach to modeling of selected human respiratory system diseases, directed to computer simulations
PublicationThis paper presents a new versatile approach to model severe human respiratory diseases via computer simulation. The proposed approach enables one to predict the time histories of various diseases via information accessible in medical publications. This knowledge is useful to bioengineers involved in the design and construction of medical devices that are employed for monitoring of respiratory condition. The approach provides the...
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EFFECT OF WORKING FLUID SELECTION ON THERMAL PERFORMANCE OF HEAT EXCHANGER FILLED BY THE POROUS MATERIAL
PublicationThermal management of electronics semiconductor technologies that are located i.e. in a novel marine power plants or computer server rooms become very important issue for designers of such systems. Motivation and need for research in development of novel cooling strategies for modern electronics is of paramount importance. Heat exchangers filled by the porous material are a novel research topic in current heat pipe science. The...
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FEM ANALYSIS AND EXPERIMENTAL TESTS OF RIGID RISER HANGING SYSTEM
PublicationThe article presents the analysis, project, and experimental examination of an original rigid riser for Coil Tubing Pipes. The principle of riser operation is based on the use of friction forces. The research included the FEM analysis of the designed riser, calculations of the required bolt tensions, and checking the effect of the clamping force on stress distribution in the pipeline. The results of computer simulation were verified...
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Concrete-filled FRP tubular members in marine and bridge structures
PublicationConcrete core of the concrete-filled tubes (CFTs) with circular cross-section is in the case of an axial compression subjected to a spatial state of compressive stresses. This state leads to enhancement in the concrete strength. The enhancement is utilized in Eurocode 4 design procedures for CFSTs (i.e. CFTs with tube made of steel). The structural design of CFFTs (i.e. CFTs with tube made of Fibre Reinforced Polymer - FRP) is...
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A Geometrically Simple Compact Wideband Circularly Polarized Antenna
PublicationA compact broadband wide-slot circular polarization (CP) antenna is proposed. An inverted L-shape parasitic strip at the open end of a microstrip line extension and a slot modification is applied to attain wideband CP. The advantage of this technique is simplicity which makes it readily re-designable for different frequency bands. To demonstrate the concept, three designs working at different frequencies are obtained. The redesign...
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Efficient Multi-Fidelity Design Optimization of Microwave Filters Using Adjoint Sensitivity
PublicationA simple and robust algorithm for computationally efficient design optimiza-tion of microwave filters is presented. Our approach exploits a trust-region (TR)-based algorithm that utilizes linear approximation of the filter response obtained using adjoint sensitivity. The algorithm is sequentially executed on a family of electromagnetic (EM)-simulated models of different fidelities, starting from a coarse-discretization one, and...
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Cost-Efficient Design Methodology for Compact Rat-Race Couplers
PublicationIn this article, a reliable and low-cost design methodology for simulation-driven optimization of miniaturized rat-race couplers (RRCs) is presented. We exploit a two-stage design approach, where a composite structure (a basic building block of the RRC structure) is first optimized using a pattern search algorithm, and, subsequently, the entire coupler is tuned by means of surrogate-based optimization (SBO) procedure. SBO is executed...
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Low-cost multiband compact branch-line coupler design using response features and automated EM model fidelity adjustment
PublicationDesign closure of compact microwave components is a challenging problem because of significant electromagnetic (EM) cross-couplings in densely arranged layouts. A separate issue is a large number of designable parameters resulting from replacement of conventional transmission line sections by compact microstrip resonant cells. This increases complexity of the design optimization problem and requires employment of expensive high-fidelity...
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Rapid design closure of microwave components by means of feature-based optimization and adjoint sensitivities
PublicationIn this article, fast design closure of microwave components using feature-based optimization (FBO) and adjoint sensitivities is discussed. FBO is one of the most recent optimization techniques that exploits a particular structure of the system response to “flatten” the functional landscape handled during the optimization process, which leads to reducing its computational complexity. When combined with gradient-based search involving...
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Inverse modeling for fast design optimization of small-size rat-race couplers incorporating compact cells
PublicationIn the paper, a framework for computationally-efficient design optimization of compact rat-race couplers (RRCs) is discussed. A class of hybrid RRCs with variable operating conditions is investigated, whose size reduction is obtained by replacing ordinary transmission lines with compact microstrip resonant cells (CMRCs). Our approach employs a bottom-up design strategy leading to the development of compact RRCs through rapid design...
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Performance‐driven modeling of compact couplers in restricted domains
PublicationFast surrogate models can play an important role in reducing the cost of EM-driven design closure of miniaturized microwave components. Unfortunately, construction of such models is challenging due to curse of dimensionality and wide range of geometry parameters that need to be included in order to make it practically useful. In this letter, a novel approach to design-oriented modeling of compact couplers is presented. Our method...
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Surrogate-assisted EM-driven miniaturization of wideband microwave couplers by means of co-simulation low-fidelity models
PublicationThis article proposes a methodology for rapid design optimization of miniaturized wideband couplers. More specifically, a class of circuits is considered, in which conventional transmission lines are replaced by their abbreviated counterparts referred to as slow-wave compact cells. Our focus is on explicit reduction of the structure size as well as on reducing the CPU cost of the design process. For the sake of computational feasibility,...
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Accelerated multi-objective design of miniaturized microwave components by means of nested kriging surrogates
PublicationDesign of microwave components is an inherently multiobjective task. Often, the objectives are at least partially conflicting and the designer has to work out a suitable compromise. In practice, generating the best possible trade‐off designs requires multiobjective optimization, which is a computationally demanding task. If the structure of interest is evaluated through full‐wave electromagnetic (EM) analysis, the employment of...
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Surrogate modeling of impedance matching transformers by means of variable‐fidelity electromagnetic simulations and nested cokriging
PublicationAccurate performance evaluation of microwave components can be carried out using full‐wave electromagnetic (EM) simulation tools, routinely employed for circuit verification but also in the design process itself. Unfortunately, the computational cost of EM‐driven design may be high. This is especially pertinent to tasks entailing considerable number of simulations (eg, parametric optimization, statistical analysis). A possible...
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Fast geometry scaling of miniaturized microwave couplers with power split correction
PublicationRedesigning a microwave circuit for various operating conditions is a practically important yet challenging problem. The purpose of this article is development and presentation of a technique for fast geometry scaling of miniaturized microwave couplers with respect to operating frequency. Our approach exploits an inverse surrogate model constructed using several reference designs that are optimized for a set of operating frequencies...
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Numerically efficient algorithm for compact microwave device optimization with flexible sensitivity updating scheme
PublicationAn efficient trust-region algorithm with flexible sensitivity updating management scheme for electromagnetic (EM)-driven design optimization of compact microwave components is proposed. During the optimization process, updating of selected columns of the circuit response Jacobian is performed using a rank-one Broyden formula (BF) replacing finite differentiation (FD). The FD update is omitted for directions sufficiently well aligned...
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Dynamic Positioning System with Vectorial Backstepping Controller
PublicationThe problem of synthesis a dynamic positioning system for low frequency model of surface vessel was considered in this paper. The recursive vectorial backstepping control design was used to keep a fixed position and heading in presence of wave disturbances. The passive observer was introduced to smooth the measurements and to estimate the velocities needed for the control algorithm. Some parameters of observer were optimized off-line...
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Virtual reality technology in architectural education
PublicationContemporary virtual reality (VR) technology allows the recreation of non-existent architectural objects of which there may be no trace remaining. Virtual reality applications allow access to digital models, which visualise the lost architecture. The popularity of VR has resulted in it being applied not only to computer games, but also in visualising the past. Maps allow movement through historical trails and 3D models of architecture...
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PROBLEMS OF THE STARTING AND OPERATING OF HYDRAULIC COMPONENTS AND SYSTEMS IN LOW AMBIENT TEMPERATURE (PART IV) MODELLING THE HEATING PROCESS AND DETERMINING THE SERVICEABILITY OF HYDRAULIC COMPONENTS DURING THE STARTING-UP IN LOW AMBIENT TEMPERATURE
PublicationDesigners of hydraulically driven machines and devices are obliged to ensure during design process their high service life with taking into account their operational conditions. Some of the machines may be started in low ambient temperature and even in thermal shock conditions (due to delivering hot working medium to cold components). In order to put such devices into operation appropriate investigations, including experimental...
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An Improved Method of Minimizing Tool Vibration during Boring Holes in Large-Size Structures
PublicationThe paper presents a thoroughly modified method of solving the problem of vibration suppression when boring large-diameter holes in large-size workpieces. A new approach of adjusting the rotational speed of a boring tool is proposed which concerns the selection of the spindle speed in accordance with the results of the simulation of the cutting process. This streamlined method focuses on phenomenological aspects and involves the...
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On Improved-Reliability Design Optimization of High-Frequency Structures Using Local Search Algorithms
PublicationThe role of numerical optimization has been continuously growing in the design of high-frequency structures, including microwave and antenna components. At the same time, accurate evaluation of electrical characteristics necessitates full-wave electromagnetic (EM) analysis, which is CPU intensive, especially for complex systems. As rigorous optimization routines involve repetitive EM simulations, the associated cost may be significant....
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Globalized Knowledge-Based Simulation-Driven Antenna Miniaturization Using Domain-Confined Surrogates and Dimensionality Reduction
PublicationDesign of contemporary antenna systems encounters multifold challenges, one of which is a limited size. Compact antennas are indispensable for the new fields of application such as inter-net of things or 5G/6G mobile communication. Still, miniaturization generally undermines elec-trical and field performance. When attempted through numerical optimization, it turns into a constrained problem with costly constraints requiring electromagnetic...
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Fast EM-Driven Nature-Inspired Optimization of Antenna Input Characteristics Using Response Features and Variable-Resolution Simulation Models
PublicationUtilization of optimization technique is a must in the design of contemporary antenna systems. Often, global search methods are necessary, which are associated with high computational costs when conducted at the level of full-wave electromagnetic (EM) models. In this study, we introduce an innovative method for globally optimizing reflection responses of multi-band antennas. Our approach uses surrogates constructed based on response...
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Mutual Coupling Reduction in Antenna Arrays Using Artificial Intelligence Approach and Inverse Neural Network Surrogates
PublicationThis paper presents a novel approach to reduce undesirable coupling in antenna arrays using custom-designed resonators and inverse surrogate modeling. To illustrate the concept, two stand-ard patch antenna cells with 0.07λ edge-to-edge distance are designed and fabricated to operate at 2.45 GHz. A stepped-impedance resonator is applied between the antennas to suppress their mutual coupling. For the first time, the optimum values...
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Recent Advances in Performance-Driven Surrogate Modeling of High-Frequency Structures
PublicationDesign of high‐frequency structures, including microwave and antenna components, heavily relies on full‐wave electromagnetic (EM) simulation models. Their reliability comes at a price of a considerable computational cost. This may lead to practical issues whenever numerous EM analyses are to be executed, e.g., in the case of parametric optimization. The difficulties entailed by massive simulations may be mitigated by the use of...
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Designing acoustic scattering elements using machine learning methods
PublicationIn the process of the design and correction of room acoustic properties, it is often necessary to select the appropriate type of acoustic treatment devices and make decisions regarding their size, geometry, and location of the devices inside the room under the treatment process. The goal of this doctoral dissertation is to develop and validate a mathematical model that allows predicting the effects of the application of the scattering...
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Human-computer interactions in speech therapy using a blowing interface
PublicationIn this paper we present a new human-computer interface for the quantitative measurement of blowing activities. The interface can measure the air flow and air pressure during the blowing activity. The measured values are stored and used to control the state of the graphical objects in the graphical user interface. In speech therapy children will find easier to play attractive therapeutic games than to perform repetitive and tedious,...
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HARDWARE AND SOFTWARE OF DIAGNOSTIC SYSTEM OF WHEELED TRACTORS = Hardwer i softwer systemu diagnostycznego ciągników kołowych
PublicationPodstawowym elementem systemu diagnostycznego jest komputer pokładowy Fujitsu FUTURO S100 z chłodzeniem pasywnym w wykonaniu odpornym na drgania i wstrząsy, z pamięcią Compact Flesh 16Gb. Do komputera dołączony jest monitor dotykowy NVOX LCD 10" VGA/FVAT. Oprogramowanie komputera obejmujesystem operacyjny Windows XP-2000, driver konwertera USB/DeviceNet oraz opracowany program diagnostyczny. Komputer połączony jest łączem USB z...
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Modeling Object Oriented Systems via Controlled English Verbalization of Description Logic
PublicationThe need for formal methods for Object Oriented (OO) systems resulted in methods like UML and Lepus3 that are de-facto graphical languages equipped with formal tools that are able to handle the design of OO systems. However, they lack precise semantics which might lead to problems, such as inconsistencies or redundancies. On the other hand, to our knowledge, there is no approach that allows one to understand and follow the requirements...
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Sebastian Wilczewski dr inż.
PeoplePhD. Sebastian Wilczewski is employed as an Assistant Professor in the Department of Applied Informatics in Management, Faculty of Management and Economics. Additionally, he has been working in IT companies for over 20 years, where he held positions from an system engineer and consultant, through the position of Project Manager, Portfolio Manager and Process Owner to the position of Team Leader for a team of about 30 IT analysts. Areas...
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Antenna Modeling Using Variable-Fidelity EM Simulations and Constrained Co-Kriging
PublicationUtilization of fast surrogate models has become a viable alternative to direct handling of fullwave electromagnetic (EM) simulations in EM-driven design. Their purpose is to alleviate the difficulties related to high computational cost of multiple simulations required by the common numerical procedures such as parametric optimization or uncertainty quantification. Yet, conventional data-driven (or approximation) modeling techniques...
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New trends in development of micro heat exchangers for ORC's
PublicationIn the paper, new trends in development of micro heat exchangers for CHP are presented. Main attention is concentrated on the question, how channels size and thermal development lenght affect the heat transfer. New types of micro heat exchangers developed at the Institute of Fluid-Flow Machinery PAS and the methoda of their design are presented. The new experimental testing methods of the micro-channel heat exchangers, new algorithms...
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Control design for slow speed positioning
PublicationThe problem under study is a synthesis of position and heading control system for low frequency model of surface vessel described by 3 DOF mathematical model. The recursive vectorial backstepping control design was used to keep fixed position and heading in presence of wave disturbances. The controller has been simulated on computer model of scaled supply vessel. It has been assumed that the actuators produce generalized forces...
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Modelowanie losowych imperfekcji geometrycznych przestrzennych konstrukcji metalowych
PublicationImperfekcje geometryczne zbiorników, silosów i powłok siatkowych mogą znaczą-co wpłynąć na ich nośność, a więc powinny być one uwzględniane w obliczeniach komputerowych i w procesie projektowania. Wykazano, że przy podstawowych obcią-żeniach, działających na tego typu konstrukcje, tj. podciśnieniu oraz naporu wiatru i śniegu (w przypadku powłok siatkowych), wykazują wyraźne różnice w porównaniu z analogicznymi wynikami dla tych...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston hydraulic pump
PublicationA novel type of an axial, piston-driven high pressure hydraulic pump with variable capacity marks a significant improvement in the area of the hydraulic machinery design. Total discharge from hydrostatic forces eliminates a need for a servomechanism, thus simplifying operation, reducing weight and introducing the possibility of the pump displacement control by computer. PWK-type pumps, invented in the Gdansk University of Technology,...
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Robust and Efficient Machine Learning Algorithms for Visual Recognition
PublicationIn visual recognition, the task is to identify and localize all objects of interest in the input image. With the ubiquitous presence of visual data in modern days, the role of object recognition algorithms is becoming more significant than ever and ranges from autonomous driving to computer-aided diagnosis in medicine. Current models for visual recognition are dominated by models based on Convolutional Neural Networks (CNNs), which...
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DIAGNOSIS OF MALIGNANT MELANOMA BY NEURAL NETWORK ENSEMBLE-BASED SYSTEM UTILISING HAND-CRAFTED SKIN LESION FEATURES
PublicationMalignant melanomas are the most deadly type of skin cancer but detected early have high chances for successful treatment. In the last twenty years, the interest of automated melanoma recognition detection and classification dynamically increased partially because of public datasets appearing with dermatoscopic images of skin lesions. Automated computer-aided skin cancer detection in dermatoscopic images is a very challenging task...
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Wiktoria Wojnicz dr hab. inż.
PeopleDSc in Mechanics (in the field of Biomechanics) - Lodz Univeristy of Technology, 2019 PhD in Mechanics (in the field of Biomechanics) - Lodz Univeristy of Technology, 2009 (with distinction) List of papers (2009 - ) Wojnicz W., Wittbrodt E., Analysis of muscles' behaviour. Part I. The computational model of muscle. Acta of Bioengineering and Biomechanics, Vol. 11, No.4, 2009, p. 15-21 Wojnicz W., Wittbrodt E., Analysis of...
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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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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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A Generalized SDP Multi-Objective Optimization Method for EM-Based Microwave Device Design
PublicationIn this article, a generalized sequential domain patching (GSDP) method for efficient multi-objective optimization based on electromagnetics (EM) simulation is proposed. The GSDP method allowing fast searching for Pareto fronts for two and three objectives is elaborated in detail in this paper. The GSDP method is compared with the NSGA-II method using multi-objective problems in the DTLZ series, and the results show the GSDP method...
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Sources of inspiration in designing ecological buildings. If not Pinterest than what?
PublicationEfficiency of ecological measures for sustainable architecture depends greatly upon the moment in which it is defined as essential, and how early it can be applied during the design concept stage. The following article refers to inspiration, the initial stage of the design and means to combine it with substantial knowledge regarding ecological architecture. Means, such as computer programs...
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Rapid Design of 3D Reflectarray Antennas by Inverse Surrogate Modeling and Regularization
PublicationReflectarrays (RAs) exhibit important advantages over conventional antenna arrays, especially in terms of realizing pencil-beam patterns without the employment of the feeding networks. Unfortunately, microstrip RA implementations feature narrow bandwidths, and are severely affected by losses. A considerably improved performance can be achieved for RAs involving grounded dielectric layers, which are also easy to manufacture using...
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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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Emotion Monitor - Concept, Construction and Lessons Learned
PublicationThis paper concerns the design and physical construction of an emotion monitor stand for tracking human emotions in Human-Computer Interaction using multi-modal approach. The concept of the stand using cameras, behavioral analysis tools and a set of physiological sensors such as galvanic skin response, blood-volume pulse, temperature, breath and electromyography is presented and followed...
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Molecular dynamics and verisimilitude - to what extent can one trust a computational simulation?
PublicationFor the last several tens of years, computer simulations have become of undeniable importance. Molecular Dynamics (MD) simulation techniques are used to examine the phenomena which occur at the level that cannot be observed directly. Thus, they can be successfully exploited in many different scientific fields such as: materials science, applied mathematics and theoretical physics, biochemistry, biophysics or drug design. Despite...
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Deep learning approach on surface EEG based Brain Computer Interface
PublicationIn this work we analysed the application of con-volutional neural networks in motor imagery classification for the Brain Computer Interface (BCI) purposes. To increase the accuracy of classification we proposed the solution that combines the Common Spatial Pattern (CSP) with convolutional network (ConvNet). The electroencephalography (EEG) is one of the modalities we try to use for controlling the prosthetic arm. Therefor in this...
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ANALYSIS OF BEARING CLEARANCE AND WIDTH OF OIL GROOVE ON CHARACTERISTIC OF FLUID FILM IN HYDRODYNAMIC MAIN CRANKSHAFT BEARINGS
PublicationAbstract Paper represents analysis of influence of oil groove width and bearing clearance on characteristics of oil film in hydrodynamic journal main crankshaft bearing. Analysis was performed in purpose to define influence of bearing clearance and dimensions of oil groove on static characteristics and manufacturability of half shelf bearings in industrial high-volume production. Computer simulations was made using ARTbear program...
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Machine Learning Algorithm-Based Tool and Digital Framework for Substituting Daylight Simulations In Early- Stage Architectural Design Evaluation
PublicationThe aim of this paper is to examine the new method of obtaining the simulation-based results using backpropagation of errors artificial neural networks. The primary motivation to conduct the research was to determine an alternative, more efficient and less timeconsuming method which would serve to achieve the results of daylight simulations. Three daylight metrics: Daylight Factor, Daylight Autonomy and Daylight Glare Probability have...
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Recent Advances in Accelerated Multi-Objective Design of High-Frequency Structures using Knowledge-Based Constrained Modeling Approach
PublicationDesign automation, including reliable optimization of engineering systems, is of paramount importance for both academia and industry. This includes the design of high-frequency structures (antennas, microwave circuits, integrated photonic components), where the appropriate adjustment of geometry and material parameters is crucial to meet stringent performance requirements dictated by practical applications. Realistic design has...
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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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Uniwersalny program komputerowy do projektowania zmiany kierunku trasy
PublicationW pracy przedstawiono kolejny program komputerowy stanowiący implementację algorytmu obliczeniowego dotyczącego projektowania zmiany kierunku trasy kolejowej, dostosowanego do techniki ciągłych pomiarów satelitarnych. Program ten ma charakter uniwersalny, gdyż w ogólnym przypadku obejmuje wprowadzenie do układu geometrycznego dwóch łuków kołowych o różnym promieniu, czyli zastosowanie łuku koszowego. Może się to okazać szczególnie...
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Using EO satellite data in Safe City and Coastal Zone web-GIS
PublicationThe paper presents a novel design of a web-based Safe City & Coastal Zone GIS (SCCZ-GIS) which integrates data acquired from different remote sensing and geospatial data sources for monitoring the security of the coastal zone, its inhabitants and Critical Infrastructure. The system utilizes several innovative technologies and directly co-operates with different remote sensing data sources and services, like a satellite ground station...
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Optimization of the Hardware Layer for IoT Systems using a Trust Region Method with Adaptive Forward Finite Differences
PublicationTrust-region (TR) algorithms represent a popular class of local optimization methods. Owing to straightforward setup and low computational cost, TR routines based on linear models determined using forward finite differences (FD) are often utilized for performance tuning of microwave and antenna components incorporated within the Internet of Things systems. Despite usefulness for design of complex structures, performance of TR methods...
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Computer Simulation in Predicting Biochemical Processes and Energy Balance at WWTPs
PublicationNowadays, the use of mathematical models and computer simulation allow analysis of many different technological solutions as well as testing various scenarios in a short time and at low financial budget in order to simulate the scenario under typical conditions for the real system and help to find the best solution in design or operation process. The aim of the study was to evaluate different concepts of biochemical processes and...
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Bidirectional Fragment to Fragment Links in Wikipedia
PublicationThe paper presents a WikiLinks system that extends the Wikipedia linkage model with bidirectional links between fragments of the articles and overlapping links’ anchors. The proposed model adopts some ideas from the research conducted in a field of nonlinear, computer-aided writing, often called a hypertext. WikiLinks may be considered as a web augmentation tool but it presents a new approach to the problem that addresses the specific...
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Ensembling noisy segmentation masks of blurred sperm images
PublicationBackground: Sperm tail morphology and motility have been demonstrated to be important factors in determining sperm quality for in vitro fertilization. However, many existing computer-aided sperm analysis systems leave the sperm tail out of the analysis, as detecting a few tail pixels is challenging. Moreover, some publicly available datasets for classifying morphological defects contain images limited only to the sperm head. This...
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Cognitum Ontorion: Knowledge Representation and Reasoning System
Publication“If knowledge can create problems, it is not through ignorance that we can solve them.” (Isaac Asimov). Nevertheless, at any point of human activity, knowledge (besides practice) is a key factor in understanding and solving any given problem. Nowadays, computer systems have the ability to support their users in an efficient and reliable way. In this paper we present and describe the functionality of the Cognitum Ontorion system....
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Behaviour of steel columns under impact
PublicationOne of import issues related to the idea of sustainable society is the safety of civil engineering structures. The safety and reliability of steel structures under impact loading is among a number of different aims during the design state. The aim of this paper is to present the results of investigation focused on dynamic behaviour of steel columns under impact loading. Modal and transient dynamic analyses using Finite Element...
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Generalized access control in hierarchical computer network
PublicationThe paper presents the design of the security layer for a distributed system located in the multizone hierarchical computer network. Depending on the zone from which a client’s request comes to the system and the type of the request, it will be either authorized or rejected. There is one common layer for the access to all the business services and interactions between them. Unlike the commonly used RBAC model, this system enforces...
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Receiver of Doppler multistatic system for moving target detection and tracking
PublicationThe article presents a method for solving major structural problems that occur in the receiver used in the multistatic Doppler system, aimed at determination of the trajectory and velocity of a moving target. In the system two transmitters emit acoustic continuous sinusoidal waves at different frequencies. The signals, scattered from a moving target are received by four hydrophones. Beside of the echoes, much larger signals coming...
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Design of reverse curves adapted to the satellite measurements
PublicationThe paper presents a new method for designing railway route in the direction change area adapted to the Mobile Satellite Measurements technique. The method may be particularly useful in the situations when both tangents cannot be connected in an elementary way using a circular arc with transition curves. Thus, the only solution would be the application of two circular arcs of opposite curvature signs, that is, the use of an inverse...
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Parametry uziemień przy przebiegach udarowych i wysokoczęstotliwościowych
PublicationW artykule skupiono się na porównaniu dwóch metod badania impedancji uziemienia odgromowego: udarowej z wysoką częstotliwościową. Zestawiono wyniki pomiarów istniejących uziemień z wynikami komputerowych obliczeń symulacyjnych przeprowadzonych w środowisku programu PSIM. Uzyskane wyniki wskazują na poprawność przyjętego toku modelowania, a uzyskane w ten sposób dane mogą być przydatne w fazie projektowania do szacowania...
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Dimensionality-Reduced Antenna Modeling with Stochastically Established Constrained Domain
PublicationOver the recent years, surrogate modeling methods have become increasingly widespread in the design of contemporary antenna systems. On the one hand, it is associated with a growing awareness of numerical optimization, instrumental in achieving high-performance structures. On the other hand, considerable computational expenses incurred by massive full-wave electromagnetic (EM) analyses, routinely employed as a major design tool,...
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Performance-driven yield optimization of high-frequency structures by kriging surrogates
PublicationUncertainty quantification is an important aspect of engineering design, as manufacturing toler-ances may affect the characteristics of the structure. Therefore, quantification of these effects is in-dispensable for adequate assessment of the design quality. Toward this end, statistical analysis is performed, for reliability reasons, using full-wave electromagnetic (EM) simulations. Still, the computational expenditures associated...
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How Integration of a Brain-Machine Interface and Obstacle Detection System Can Improve Wheelchair Control via Movement Image
PublicationThis study presents a human-computer interaction combined with a brain-machine interface (BMI) and obstacle detection system for remote control of a wheeled robot through movement imagery, providing a potential solution for individuals facing challenges with conventional vehicle operation. The primary focus of this work is the classification of surface EEG signals related to mental activity when envisioning movement and deep relaxation...