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Wyniki wyszukiwania dla: CIRCULAR POLARIZATION , ANTENNA DESIGN , SIMULATION-DRIVEN DESIGN , WIDE-ANGLE BEAM , BROADBAND ANTENNA
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Implicit Space Mapping for Variable-Fidelity EM-Driven Design of Compact Circuits
PublikacjaSpace mapping (SM) belongs to the most successful surrogate-based optimization (SBO) methods in microwave engineering. Among available SM variations, implicit SM (ISM) is particularly attractive due to its simplicity and separation of extractable surrogate model parameters and design variables of the circuit/system at hand. Unlike other SM approaches, ISM exploits a set of preassigned parameters to align the surrogate with the...
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Compact Electromagnetic Lens Antennas Using Cascaded Metasurfaces for Gain Enhancement and Beam Steering Applications
PublikacjaElectromagnetic (EM) lens antenna designs using cascaded metasurfaces for gain enhancement and beam steering applications are proposed. Two different lens aperture designs are proposed and populated with aperiodic unit cells of size 0.2λo × 0.2λo. In lens Design 1, the unit cells of different phases are distributed in concentric circular zones, whereas in lens Design 2, the unit cells of different phases are distributed in vertical...
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Simple 60 GHz Switched Beam Antenna for 5G Millimeter-Wave Applications
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On Alternative Approaches to Design of Corporate Feeds for Low-Sidelobe Microstrip Linear Arrays
PublikacjaTwo design approaches, illustrated by simulations and measurements, aiming at a systematic computer-aided design of printed circuit feeds for low-sidelobe microstrip antenna arrays are described. The novelty of these approaches resides in identification of the optimal feed architectures with subsequent simulation-based optimization of the feed and array aperture dimensions. In this work, we consider microstrip corporate feeds realizing...
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Design of a microrobotic wrist for needle laparoscopic surgery
PublikacjaThe 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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Bayesian Optimization for solving high-frequency passive component design problems
PublikacjaIn 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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Influence of ESPAR Antenna Radiation Patterns Shape on PPCC-Based DoA Estimation Accuracy
PublikacjaIn 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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Ultra-Compact Self-Quadruplexing Microfluidically Frequency Reconfigurable Slot Antenna Using Half-Mode SIW
PublikacjaIn this brief, the design of an ultra-compact self-quadruplexing frequency reconfigurable antenna (SQFRA) utilizing a half-mode substrate-integrated waveguide (HMSIW) and microfluidic channels is discussed. Four HMSIW cavities fed by four microstrip lines and slots are used to construct a highly compact antenna. The microstrip feedings to the HMSIW cavities are applied in such a way that the proposed antenna exhibits self-quadruplexing...
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Frequency-Reconfigurable Hybrid SIW-Based Self-Diplexing Antenna Using Solid and Liquid Dielectric Loading
PublikacjaThis paper presents a novel frequencyreconfigurable self-diplexing antenna (SDA) utilizing a hybrid substrate-integrated waveguide (SIW). The antenna comprises a radiating slot, a feeding network, and a hybrid SIW cavity featuring half-mode circular and half-mode rectangular SIW structures. The unique feature of this antenna lies in its fine-tuning capability of each resonant frequency by inserting or injecting solid and liquid...
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Domain segmentation for low-cost surrogate-assisted multi-objective design optimisation of antennas
PublikacjaAbstract: Information regarding the best possible design trade-offs of an antenna structure can be obtained through multiobjective optimisation (MO). Unfortunately, MO is extremely challenging if full-wave electromagnetic (EM) simulation models are used for performance evaluation. Yet, for the majority of contemporary antennas, EM analysis is the only tool that ensures reliability. This study introduces a procedure for accelerated...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston pump
PublikacjaA 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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Rapid EM-Driven Design of Compact RF Circuits By Means of Nested Space Mapping
PublikacjaA methodology for rapid design of RF circuits constituted by compact microstrip resonant-cells (CMRCs) is presented. Our approach exploits nested space mapping (NSM) technology, where the inner SM layer is used to correct the equivalent circuit model at the CMRC level, whereas the outer layer enhances the coarse model of the entire structure under design. We demonstrate that NSM dramatically improves performance of surrogate-based...
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Fast surrogate-assisted frequency scaling of planar antennas with circular polarisation
PublikacjaIn this work, the problem of computationally efficient frequency scaling (re-design) of circular polarisation antennas is addressed using surrogate-assisted techniques. The task is challenging and requires the identification of the optimum geometry parameters to enable the operation of the re-designed structure at a selected (required) centre frequency. This involves handling several performance figures such as the antenna gain,...
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Expedited Design Closure of Antennas By Means Of Trust-Region-Based Adaptive Response Scaling
PublikacjaIn the letter, a reliable procedure for expedited design optimization of antenna structures by means of trust-region adaptive response scaling (TR-ARS) is proposed. The presented approach exploits two-level electromagnetic (EM) simulation models. A predicted high-fidelity model response is obtained by applying nonlinear frequency and amplitude correction to the low-fidelity model. The surrogate created this way is iteratively rebuilt...
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Wideband High-Gain Low-Profile Series-Fed Antenna Integrated with Optimized Metamaterials for 5G millimeter Wave Applications
PublikacjaThis paper presents a series-fed four-dipole antenna with a broad bandwidth, high gain, and compact size for 5G millimeter wave (mm-wave) applications. The single dipole antenna provides a maximum gain of 6.2 dBi within its operational bandwidth, which ranges from 25.2 to 32.8 GHz. The proposed approach to enhance both gain and bandwidth involves a series-fed antenna design. It comprises four dipoles with varying lengths, and a...
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Expedited EM-Driven Design of Miniaturized Microwave Hybrid Couplers Using Surrogate-Based Optimization
PublikacjaMiniaturization of microwave hybrid couplers is important for contemporary wireless communication engineering. Using standard computer-aided design methods for development of compact structures is extremely challenging due to a general lack of computationally efficient and accurate simulation models. Poor accuracy of available equivalent circuits results from neglecting parasitic cross-couplings that greatly affect the performance...
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RSS-Based DoA Estimation in 802.11p Frequency Band Using ESPAR Antenna and PPCC-MCP Method
PublikacjaIn this paper, the concept of direction of arrival (DoA) estimation using electronically steerable parasitic array radiator (ESPAR) antenna designed to operate in IEEE 802.11p vehicular communication standard has been investigated with respect to different possible elevation angles of a radio frequency (RF) signal impinging the antenna. To this end, two different possible sets of the 3D antenna radiation patterns have been used...
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Rapid Multi-band Patch Antenna Yield Estimation Using Polynomial Chaos-Kriging
PublikacjaYield estimation of antenna systems is important to check their robustness with respect to the uncertain sources. Since the Monte Carlo sampling-based real physics simulation model evaluations are computationally intensive, this work proposes the polynomial chaos-Kriging (PC-Kriging) metamodeling technique for fast yield estimation. PC-Kriging integrates the polynomial chaos expansion (PCE) as the trend function of Kriging metamodel...
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Low-cost multiband four-port phased array antenna for sub-6 GHz 5G applications with enhanced gain methodology in Radio-over-fiber systems using modulation instability
PublikacjaPhased array antenna (PAA) technology is essential for applications requiring high gain and wide bandwidth, such as sensors, medical, and 5G. Achieving such a design, however, is a challenging and intricate process that calls for precise calculations and a combination of findings to alter the phase and amplitude of each unit. Furthermore, coupling effects between these PAA structure elements can only be completed with the use of...
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Accelerated design optimization of miniaturized microwave passives by design reusing and Kriging interpolation surrogates
PublikacjaElectromagnetic (EM) analysis has become ubiquitous in the design of microwave components and systems. One of the reasons is the increasing topological complexity of the circuits. Their reliable evaluation—at least at the design closure stage—can no longer be carried out using analytical or equivalent network representations. This is especially pertinent to miniaturized structures, where considerable EM cross-coupling effects occurring...
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Adaptive Wavelet-Based Correction of Non-Anechoic Antenna Measurements
PublikacjaNon-anechoic measurements represent an affordable alternative to evaluation of antenna performance in expensive, dedicated facilities. Due to interferences and noise from external sources of EM radiation, far-field results obtained in non-ideal conditions require additional post-processing. Conventional correction algorithms rely on manual tuning of parameters, which make them unsuitable for reliable testing of prototypes. In this...
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Improved RSS-Based DoA Estimation Accuracy in Low-Profile ESPAR Antenna Using SVM Approach
PublikacjaIn this paper, we have shown how the overall performance of direction-of-arrival (DoA) estimation using lowprofile electronically steerable parasitic array radiator (ESPAR) antenna, which has been proposed for Internet of Things (IoT) applications, can significantly be improved when support vector machine (SVM) approach is applied. Because the SVM-based DoA estimation method used herein relies solely on received signal strength...
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Simulation of fluid structure interaction in a novel design of high pressure axial piston hydraulic pump
PublikacjaA 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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Economical wood sawing with circular saw blades of a new design (Ekonomicno piljenje drva kruznom pilom novog dezajna)
PublikacjaMaterial-saving and energy-saving belong to the basic requirements imposed on contemporary manufacturing processes. The realization of these processes gives measurable profi ts, not only economical butalso ecological. In the case of wood sawing with circular saw blades, material- and energy-savings are dependent on total overall set of teeth (theoretical kerf) and teeth position accuracy in relation to the workpiece. Hence, it...
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Dual-band Millimetre Wave MIMO Antenna with Reduced Mutual Coupling Based on Optimized Parasitic Structure and Ground Modification
PublikacjaIn this study, a high-isolation dual-band (28/38 GHz) multiple-input–multiple-output (MIMO) antenna for 5G millimeter-wave applications is presented. The antenna consists of two interconnected patches. The primary patch is connected to the inset feed, while the secondary patch is arc-shaped and positioned over the main patch, opposite to the feed. Both patches function in the lower 28 GHz band, while the primary patch is accountable...
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A framework for accelerated optimization of antennas using design database and initial parameter set estimation
PublikacjaThe purpose of this paper is to exploit a database of pre-existing designs to accelerate parametric optimization of antenna structures is investigated. Design/methodology/approach The usefulness of pre-existing designs for rapid design of antennas is investigated. The proposed approach exploits the database existing antenna base designs to determine a good starting point for structure optimization and its response sensitivities....
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A biochemical multi-species quality model of a drinking water distribution system for simulation and design
PublikacjaDrinking Water Distribution Systems (DWDSs) play a key role in sustainable development of modern society. They are classified as critical infrastructure systems. This imposes a large set of highly demanding requirements on the DWDS operation and requires dedicated algorithms for on-line monitoring and control to tackle related problems. Requirements on DWDS availability restrict the usability of the real plant in the design phase....
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Influence of User Mobility and Antenna Placement on System Loss in B2B Networks
PublikacjaIn this paper, the influence of user mobility and on-body antenna placement on system loss in body-to-body communications in indoor and outdoor environments and different mobility scenarios is studied, based on system loss measurements at 2.45 GHz. The novelty of this work lies on the proposal of a classification model to characterise the effect of user mobility and path visibility on system loss, allowing to identify the best...
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Novel Versatile Topologies and Design Optimization of Wide-Bandstop Frequency Selective Surfaces for X-Band, Ku-Band and Millimeter-Wave Applications
PublikacjaNovel designs of frequency selective surface (FSS) are presented for wideband applications in X, Ku and mmWave (millimeter Wave) bands. Two identical metallic layers of FSS are imprinted on both sides of the RO4003 substrate. The geometry parameters are optimized to maximize the bandstop at the specified in-band maximum transmission level of –10 dB; satisfaction of the latter condition is enforced through appropriate formulation...
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Performance-Driven Surrogate Modeling of High-Frequency Structures
PublikacjaThe 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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Improved Uniform Sampling in Constrained Domains for Data-Driven Modelling of Antennas
PublikacjaData-driven surrogate modelling of antenna structures is an attractive way of accelerating the design process, in particular, parametric optimization. In practice, construction of surrogates is hindered by curse of dimensionality as well as wide ranges of geometry parameters that need to be covered in order to make the model useful. These difficulties can be alleviated by constrained performance-driven modelling with the surrogate...
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Examination method of the effect of the incidence angle of laser beam on distance measurement accuracy to surfaces with different colour and roughness
PublikacjaInterest in the influence of the incidence angle of a laser beam to distance measurements can be seen in many areas of science and technology: geodesy, glaciology, archaeology, machine automation, and others. This paper presents results of measurements of the effect of the incidence angle of a laser beam to distance measurements to the surfaces of different colour and roughness by Topcon's electro-optical total station with an...
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Design-oriented computationally-efficient feature-based surrogate modelling of multi-band antennas with nested kriging
PublikacjaDesign of modern antenna structures heavily depends on electromagnetic (EM) simulation tools. EM analysis provides reliable evaluation of increasingly complex designs but tends to be CPU intensive. When multiple simulations are needed (e.g., for parameters tuning), the aggregated simulation cost may become a serious bottleneck. As one possible way of mitigating the issue, the recent literature fosters utilization of faster representations,...
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Pantographic metamaterials: an example of mathematically driven design and of its technological challenges
PublikacjaIn this paper, we account for the research efforts that have been started, for some among us, already since 2003, and aimed to the design of a class of exotic architectured, optimized (meta) materials. At the first stage of these efforts, as it often happens, the research was based on the results of mathematical investigations. The problem to be solved was stated as follows: determine the material (micro)structure governed by those...
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An attempt to develop a model selection algorithm of computer simulation during the design process of mechanical response of any mechanical body
Publikacjan the literature, there are algorithms associated with the design of simulations of technological processes, in which the material model has always been defined previously. However, in none of the studies of computer simulation modelling of technological processes known to the authors of this article, is there a detailed description of how the algorithm, or the selection of plastic model used, is subject to this process. This article...
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An Attempt to Develop a Model Selection Algorithm of Computer Simulation during the Design Process of Mechanical Response of Any Mechanical Body
PublikacjaIn the literature, there are algorithms associated with the design of simulations of technological processes, in which the material model has always been defined previously. However, in none of the studies of computer simulation modelling of technological processes known to the authors of this article, is there a detailed description of how the algorithm, or the selection of plastic model used, is subject to this process. This...
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Automatic Correction of Non-Anechoic Antenna Measurements using Low-Pass Filters
PublikacjaPrototype measurements belong to key steps in the development of antenna structures. They are normally performed in expensive facilities, such as anechoic chambers (ACs). Alternatively, antenna performance can be extracted (at a low cost) in non-anechoic conditions upon appropriate post-processing. Unfortunately, existing correction algorithms are difficult to set up and prone to failure, which limits their practical usefulness....
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Low-Cost Open-Hardware System for Measurements of Antenna Far-Field Characteristics in Non-Anechoic Environments
PublikacjaExperimental validation belongs to the most important steps in the development of antenna structures. Measurements are normally performed in expensive, dedicated facilities such as anechoic chambers, or open-test sites. A high cost of their construction might not be justified when the main goal of antenna verification boils down to demonstration of the measurement procedure, or rough validation of the simulation models used for...
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High gain/bandwidth off‑chip antenna loaded with metamaterial unit‑cell impedance matching circuit for sub‑terahertz near‑field electronic systems
PublikacjaAn innovative off-chip antenna (OCA) is presented that exhibits high gain and efficiency performance at the terahertz (THz) band and has a wide operational bandwidth. The proposed OCA is implemented on stacked silicon layers and consists of an open circuit meandering line. It is shown that by loading the antenna with an array of subwavelength circular dielectric slots and terminating it with a metamaterial unit cell, its impedance...
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Rapid Design of 3D Reflectarray Antennas by Inverse Surrogate Modeling and Regularization
PublikacjaReflectarrays (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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Local-Global Space Mapping for Rapid EM-Driven Design of Compact RF Structures
PublikacjaIn this work, we introduce a robust and efficient technique for rapid design of compact RF circuits. Our approach exploits two-level space mapping (SM) correction of an equivalent circuit model of the structure under design. The first SM layer (local correction) is utilized to ensure good matching between the equivalent circuit and the electromagnetic model at the component level. On the other hand, the global correction allows...
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Reinforcement Learning Algorithm and FDTD-based Simulation Applied to Schroeder Diffuser Design Optimization
PublikacjaThe aim of this paper is to propose a novel approach to the algorithmic design of Schroeder acoustic diffusers employing a deep learning optimization algorithm and a fitness function based on a computer simulation of the propagation of acoustic waves. The deep learning method employed for the research is a deep policy gradient algorithm. It is used as a tool for carrying out a sequential optimization process the goal of which is...
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The Way One Defines Specification Matters: On the Performance Criteria for Efficient Antenna Optimization in Aggregated Bi-Objective Setups
PublikacjaDesign of antenna structures for real-world applications is a challenging task that often involves addressing multiple design requirements at a time. Popular solution approaches to this class of problems include utilization of composite objectives. Although configuration of such functions has a significant effect on the cost and performance of the optimization, their specific structure is normally determined based on engineering...
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Fast Multi-Objective Optimization of Narrow-Band Antennas Using RSA Models and Design Space Reduction
PublikacjaComputationally efficient technique for multi-objective design optimization of narrow-band antennas is presented. In our approach, the corrected low-fidelity antenna model (obtained through coarse-discretization EM simulations) is enhanced using frequency scaling and response correction, sampled, and utilized to obtain a fast response surface approximation (RSA) antenna surrogate. The RSA model is constructed in the reduced design space....
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Key success factors for small design offices in the bidding process
PublikacjaCompetition in the design office market is high, therefore it is important to be aware of the conditions determining the competitive advantage, thus increasing the bidding effectiveness. For this reason, the aim of the article is to identify key success factors (KSF) increasing successful bidding of a small design office. The factors were identified and then analysed based on a literature review, expert interviews and using Group...
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Low-Cost Multi-Objective Optimization Yagi-Uda Antenna in Multi-Dimensional Parameter Space
PublikacjaA surrogate-based technique for fast multi-objective optimization of a multi-parameter planar Yagi-Uda antenna structure is presented. The proposed method utilizes response surface approximation (RSA) models constructed using training samples obtained from evaluation of the low-fidelity antenna model. Utilization of the RSA models allowsfor fast determination of the best possible trade-offs between conflicting objectives in multi-objective...
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Cost-efficient multi-objective design optimization of antennas in highly-dimensional parameter spaces
PublikacjaMulti-objective optimization of antenna structures in highly-dimensional parameter spaces is investigated. For expedited design, variable-fidelity EM simulations and domain patching algorithm are utilized. The results obtained for a monopole antenna with 13 geometry parameters are compared with surrogate-assisted optimization involving response surface approximation modeling.
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Detection and Direction-of-Arrival Estimation of Weak Spread Spectrum Signals Received with Antenna Array
PublikacjaThis paper presents a method for the joint detection and direction of arrival (DOA) estimation of low probability of detection (LPD) signals. The proposed approach is based on using the antenna array to receive spread-spectrum signals hidden below the noise floor. Array processing exploits the spatial correlation between phase-delayed copies of the signal and allows us to evaluate the parameter used to make the decision about the...
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Ultra-Wideband Vivaldi Antenna with an Integrated Noise-Rejecting Parasitic Notch Filter for Online Partial Discharge Detection
PublikacjaPower transformers and gas-insulated switchgear (GIS) play crucial roles in electrical power grids. However, they may suffer from degradation of insulation material due to wear and tear, leading to their imminent failure. Partial discharges (PDs) are an initial sign of insulation materials degradation which emit signals spanning various physical domains, including electromagnetic. PDs are temporally narrow, high-frequency, stochastic...
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Design thinking (DT) for the design and planning education of engineer-architects
PublikacjaEngineers are facing new challenges connected with globalisation, digitisation and the increased complexity of the design process. This calls for new, more interdisciplinary and user-oriented approaches to problem- solving. In this article, the authors analyse design thinking (DT) as a method to support the education of engineers specialising in architecture and urban planning. Identified in this study are the opportunities this...