Search
Search results for: EM SIMULATION
-
A compact microstrip rat-race coupler constituted by nonuniform transmission lines
PublicationIn this work, a step-by-step development of a compact microstrip rat-race coupler (RRC) has been presented and discussed. A high degree of miniaturization has been obtained by substituting six quarter-wavelength uniform atomic building blocks of a RRC by their nonuniform counterparts. The miniaturization procedure has been realized in three progressive steps: (i) the first layout solution of a miniaturized RRC has been acquired...
-
Rapid antenna design optimization using shape-preserving response prediction
PublicationAn approach to rapid optimization of antennas using the shape-preserving response-prediction (SPRP) technique and coarsediscretization electromagnetic (EM) simulations (as a low-fidelity model) is presented. SPRP allows us to estimate the response of the high-fidelity EM antenna model, e.g., its reflection coefficient versus frequency, using the properly selected set of so-called characteristic points of the low-fidelity model...
-
Comprehensive dimension scaling of multi-band antennas for operating frequencies and substrate parameters
PublicationIn this paper, low-cost and comprehensive redesign of multi-band antennas with respect to the operating frequencies and material parameters of the substrate is presented. Our approach exploits an inverse surrogate model identified based on a set of reference designs optimized at the level of coarse-discretization EM simulations of the antenna at hand. An iterative correction procedure is also implemented to account for the initial...
-
Development of Biocompatible Fe3O4@SiO2 Nanoparticles as Subcellular Delivery Platform for Glucosamine-6-phosphate Synthase Inhibitors
PublicationNumerous inhibitors of glucoseamine-6-phophate synthase (GlcN-6-P), the enzyme responsible from catalysis of the first step of metabolic pathway leading to metabolism 5’-diphospho-N-acetyl-D- glucosamine, were reported as effective agents for inhibiting the growth of various fungal pathogens. Among the reported inhibitors,...
-
Degradacja nawierzchni w świetle pomiarów drezyną EM-120
PublicationW referacie przedstawiono możliwości wykorzystania wyników pomiarów drezyną EM-120 do określania tempa zmian w położeniu toków szynowych w płaszczyźnie pionowej i poziomej. Zaprezentowana analiza umożliwia właściwy monitoring i planowanie terminów przeprowadzania regulacji położenia toru.
-
Cost-efficient multi-objective design optimization of antennas in highly-dimensional parameter spaces
PublicationMulti-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.
-
Urbansketching
PublicationKatalog wystawy prezentującej dorobek warsztatów Urban Sketchers em Benfica : viajar pelo bairro com um caderno, które odbyły się w Lizbonie w dzielnicy Benfica 6 listopada 2011. Na stronach 20 i 21 tekst autora i 4 rysunki
-
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...
-
EM-driven topology evolution for bandwidth enhancement of hybrid quadrature patch couplers
PublicationA broad operational bandwidth is one of the key performance figures of hybrid patch couplers. Due to the lack of systematic design procedures, bandwidth enhancement is normally obtained through manual modifications of the structure geometry. In this work, an optimization-based topology evolution for EM-driven design of patch couplers with enhanced bandwidth has been proposed. The method exploits a novel spline-based EM model where...
-
Statistical analysis and robust design of circularly polarized antennas using sequential approximate optimization
PublicationIn the paper, reliable yield estimation and tolerance-aware design optimization of circular polarization (CP) antennas is discussed. We exploit auxiliary kriging interpolation models established in the vicinity of the nominal design in order to speed up the process of statistical analysis of the antenna structure at hand. Sequential approximate optimization is then applied to carry out robust design of the antenna, here, oriented...
-
What is important for you makes you think about the pandemic differently: moral foundations, pandemic-related fears and convictions (Lo que cada uno consideramos importante nos hace reflexionar sobre la pandemia de forma distinta: fundamentos morales, temores y convicciones sobre la pandemia)
PublicationBuilding on the Moral Foundations Theory and findings regarding the linkage of values, convictions and beliefs, the aim of the study was to compare people displaying various constellations of moral foundations regarding their tolerance of ambiguity, fear of COVID-19 (FCV), endorsement of COVID-19 conspiracy theories and the extent to which they believed in the effectiveness of five COVID-19 preventive measures. This study was...
-
Dobre praktyki w zakresie wzmacniania interesariuszy regionalnych systemów innowacji
PublicationCelem Regionalnej Strategii Innowacji Województwa Podkarpackiego na lata 2021-2030 jest transformacja systemu gospodarczego województwa podkarpackiego w kierunku gospodarki konkurencyjnej, opartej na wiedzy i wykorzystaniu nowoczesnych technologii, uwzględniającej aspiracje przedsiębiorców, społeczeństwa oraz globalne uwarunkowania rozwoju. Do osiągnięcia tego celu niezbędna jest współpraca wszystkich elementów tworzących...
-
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...
-
Design of a compact planar transmission line for miniaturized rat-race coupler with harmonics suppression
PublicationThis paper presents an elegant yet straightforward design procedure for a compact rat-race coupler (RRC) with an extended harmonic suppression. The coupler’s conventional λ/4 transmission lines (TLs) are replaced by a specialized TL that offers significant size reduction and harmonic elimination capabilities in the proposed approach. The design procedure is verified through the theoretical, circuit, and electromagnetic (EM) analyses,...
-
Rapid tolerance‐aware design of miniaturized microwave passives by means of confined‐domain surrogates
PublicationThe effects of uncertainties, primarily manufacturing tolerances but also incomplete information about operating conditions or material parameters, can be detrimental to the performance of microwave components. Quantification of such effects is essential to ensure a meaningful evaluation of the structure, in particular, its reliability under imperfect fabrication procedures. The improvement of the circuit robustness can be achieved...
-
Generalized Formulation of Response Features for Reliable Optimization of Antenna Input Characteristics
PublicationElectromagnetic (EM)-driven parameter adjustment has become imperative in the design of modern antennas. It is necessary because the initial designs rendered through topology evolution, parameter sweeping, or theoretical models, are often of poor quality and need to be improved to satisfy stringent performance requirements. Given multiple objectives, constraints, and a typically large number of geometry parameters, the design closure...
-
Rapid design optimization of compact couplers using response features and adjoint sensitivities
PublicationA technique for rapid EM-driven design optimization of compact microwave couplers is presented. Our approach exploits response features and adjoint sensitivities and allows for low-cost design closure both in terms of performance enhancement and structure miniaturization. It is demonstrated using a compact rat-race coupler working at 1 GHz and compared to adjoint-based gradient optimization.
-
Kriging metamodels and design re‐utilization for fast parameter tuning of antenna structures
PublicationThe paper addresses the problem of computationally efficient electromagnetic (EM)‐driven design closure of antenna structures. The foundations of the presented approach are fast kriging interpolation metamodels, utilized for two purposes: (a) producing a good starting point for further parameter tuning, and (b) yielding a reasonable Jacobian matrix estimate to jump‐start the optimization procedure. The models are rendered using...
-
Performance-Driven Inverse/Forward Modeling of Antennas in Variable-Thickness Domains
PublicationDesign of contemporary antenna systems is a challenging endeavor. The difficulties are partially rooted in stringent specifications imposed on both electrical and field characteristics, demands concerning various functionalities, but also constraints imposed upon the physical size of the radiators. Furthermore, conducting the design process at the level of full-wave electromagnetic (EM) simulations, otherwise dictated by reliability,...
-
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...
-
Scattering in a section of ferrite coupled microstrip lines: theory and application in nonreciprocal devices
PublicationPrzeprowadzono analizę pełnofalową sekcji sprzężonych ferrytowych linii mikropaskowych wykorzystującą w rozwinięciu pola em fale prowadzone w izotropowych złączach wejściowych sekcji oraz jej fajl ferrytowych. W wyniku określono macierz S sekcji. Przeprowadzono modelowanie własności rozproszenia układu oraz symulację parametrów transmisyjnych układów niewzajemnych projektowanych z wykorzystaniem proponowanego układu ferrytowego.
-
Improved-Efficacy EM-Driven Optimization of Antenna Structures Using Adaptive Design Specifications and Variable-Resolution Models
PublicationOptimization-driven parameter tuning is an essential step in the design of antenna systems. Although in many cases it is still conducted through parametric studies, rigorous numerical methods become a necessity if truly optimum designs are sought for, and the problem intricacies (number of variables, multiple goals, constraints) make the interactive approaches insufficient. The two practical considerations of electromagnetic (EM)-driven...
-
Machine-Learning-Powered EM-Based Framework for Efficient and Reliable Design of Low Scattering Metasurfaces
PublicationPopularity of metasurfaces has been continuously growing due to their attractive properties including the ability to effectively manipulate electromagnetic (EM) waves. Metasurfaces comprise optimized geometries of unit cells arranged as a periodic lattice to obtain a desired EM response. One of their emerging application areas is the stealth technology, in particular, realization of radar cross section (RCS) reduction. Despite...
-
Design centering of compact microwave components using response features and trust regions
PublicationFabrication tolerances, as well as uncertainties of other kinds, e.g., concerning material parameters or operating conditions, are detrimental to the performance of microwave circuits. Mitigating their impact requires accounting for possible parameter deviations already at the design stage. This involves optimization of appropriately defined statistical figures of merit such as yield. Alt-hough important, robust (or tolerance-aware)...
-
Expedited Yield-Driven Design of High-Frequency Structures by Kriging Surrogates in Confined Domains
PublicationUncertainty quantification is an important aspect of engineering design, also pertaining to the development and performance evaluation of high-frequency structures systems. Manufacturing tolerances as well as other types of uncertainties, related to material parameters (e.g., substrate permittivity) or operating conditions (e.g., bending) may affect the characteristics of antennas or microwave devices. For example, in the case...
-
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...
-
Multi-Objective Design Optimization of Compact Quasi-Isotropic Dielectric Resonator Antenna
PublicationMulti-objective optimization of a quasi-isotropic dielectric resonator antenna (DRA) is presented. Utilization of variable-fidelity electromagnetic (EM) DRA models, response surface approximations, and response correction techniques, allows us to obtain—at a low computational cost—a set of alternative antenna designs representing the best possible trade-offs between three conflicting objectives: antenna size, its reflection response,...
-
Small Antenna Design Using Surrogate-Based Optimization
PublicationIn this work, design of small antennas using efficient numerical optimization is investigated. We exploit variable-fidelity electromagnetic (EM) simulations and the adaptively adjusted design specifications (AADS) technique. Combination of these methods allows us to simultaneously adjust multiple geometry parameters of the antenna structure of interest in a computationally feasible manner, leading to substantial reduction of the...
-
Reconstruction of thin films polyazomethine based on microscopic images
PublicationPurpose: The aim of this paper was to investigate changes in surface morphology of thin films ofpolyazomethine PPI. Thin films were prepared using low-temperature chemical vapor deposition (CVD)method.Design/methodology/approach: The changes in surface topography was observed by the atomicforce microscope AFM and scanning electron microscope SEM. The results of roughness have beenprepared in the software WSxM NanoTec Spanish...
-
Słowiańska psychomachia Mickiewicza (książka)
PublicationJest to praca na niebagatelny temat, o który nieraz potrącali autorzy publikacji o Mickiewiczu i historycy polskiej literatury romantycznej, ale - jeśli się nie mylę - nie czynili go dotychczas przedmiotem rozważań systematycznych i nie poświęcili mu osobnych monografii. Zbigniew Kaźmierczyk zdecydował się na całościowe sprawdzenie, jakie echa wierzeń religijnych zamierzchłej przeszłości dziejowej odzywały się w pisarstwie Mickiewicza...
-
Metal tolerance and Cd phytoremoval ability in Pisum sativum grown in spiked nutrient solution
PublicationIn the presented study, the effects of cadmium (Cd) stress and silicon (Si) supplementation on the pea plant (Pisum sativum L.) were investigated. The tendency to accumulate cadmium in the relevant morphological parts of the plant (roots and shoots respectively)—bioaccumulation, the transfer of this element in the plant (translocation) and the physiological parameters of the plant through...
-
The mediational role of future and past time perspectives in the relationship between negative affectivity and sense of coherence
PublicationSense of coherence (SoC) can promote positive coping, and one of its most prominent negative correlates is negative affectivity (NA). In the current study, we hypothesized that future and past time perspectives (TPs) will mediate the relationship between sense of coherence and negative affectivity, and the inverse relationship. The study was questionnaire-based, performed online. N = 719 participants aged 25-45 from...
-
The influence of plant protection by effective microorganisms on the content of bioactive phytochemicals in apples
PublicationThe phytochemicals of two apple cultivars (Yellow Transparent and Early Geneva) protected in two ways, conventionally with chemical pesticides or by effective microorganisms (EM), were compared. Two types of components were determined: lipids synthesised constitutively and generated via inducible pathways polyphenols along with antioxidant activity and profiles. The antioxidant activities assessed with ABTS, DPPH and Folin–Ciocalteu...
-
Selection of circuit geometry for miniaturized microwave components based on concurrent optimization of performance and layout area
PublicationThe paper presents a framework for automated EM-driven circuit geometry selection of miniaturized microwave components. Selection of a particular layout is based directly on miniaturization rates achieved for a set of candidate circuit geometries. Size reduction of the considered structures is obtained by replacing their main building blocks (i.e., conventional transmission lines) with slow-wave composite cells and meander lines....
-
Response features for fast EM-driven design of miniaturized impedance matching transformers
PublicationA framework for low-cost EM-driven design optimization of compact impedance matching transformers is presented. Our technique is based on a bottom-up design where design requirements for the transformer circuit are translated into specifications for its building blocks. These elementary cells are optimized using response features. Subsequently, the entire circuit is fine-tuned using local response surface approximation models and...
-
IR and microscopic studies of polyurethane surface in the polish extracorporeal ventricular assist device POLVAD-MEV
PublicationPurpose: The aim of this article is to show results of IR measurements and microscopicanalysis performed on layers prepared with dissolved VAD fragments and pieces ofventricular assist devices cut out of from determined VAD sectors.Design/methodology/approach: The objects of the study have been POLVAD-MEVVADs from POLCAS system. Four ventricular assist devices POLVAD-MEV have beeninvestigated with use M80 SPECORD IR spectrophotometer...
-
Reliable Surrogate Modeling of Antenna Input Characteristics by Means of Domain Confinement and Principal Components
PublicationA reliable design of contemporary antenna structures necessarily involves full-wave electromagnetic (EM) analysis which is the only tool capable of accounting, for example, for element coupling or the effects of connectors. As EM simulations tend to be CPU-intensive, surrogate modeling allows for relieving the computational overhead of design tasks that require numerous analyses, for example, parametric optimization or uncertainty...
-
Rapid Re-Design and Bandwidth/Size Trade-Offs for Compact Wideband Circular Polarization Antennas Using Inverse Surrogates and Fast EM-Based Parameter Tuning
PublicationDesign of compact wideband circularly polarized (CP) antennas is challenging due to the necessity of simultaneous handling of several characteristics (reflection, axial ratio, gain) while maintaining a small size of the structure. Antenna re-design for various operating bands is clearly more difficult yet practically important because intentional reduction of the bandwidth (e.g., by moving the lower edge of the operating band up...
-
Compact Electromagnetic Lens Antennas Using Cascaded Metasurfaces for Gain Enhancement and Beam Steering Applications
PublicationElectromagnetic (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...
-
Design of High-Performance Scattering Metasurfaces through Optimization-Based Explicit RCS Reduction
PublicationThe recent advances in the development of coding metasurfaces created new opportunities in realization of radar cross section (RCS) reduction. Metasurfaces, composed of optimized geometries of meta-atoms arranged as periodic lattices, are devised to obtain desired electromagnetic (EM) scattering characteristics. Despite potential benefits, their rigorous design methodologies are still lacking, especially in the context of controlling...
-
Novel Structure and EM-Driven Design of Small UWB Monopole Antenna
PublicationA novel structure of a small UWB monopole antenna is presented. In our approach, a compact size is achieved by means of a meander line for current path enlargement as well as the two parameterized slits that introduce additional degrees of freedom helping to ensure good impedance matching. The antenna design is carried out using surrogate-based optimization involving variable-fidelity EM simulations. This allows us to simultaneously...
-
A Concept and Design Optimization of Compact Planar UWB Monopole Antenna
PublicationA novel structure concept of a compact UWB monopole antenna is introduced together with a low-cost design optimization procedure. Reduced footprint is achieved by introduction of a protruded ground plane for current path increase and a matching transformer to ensure wideband impedance matching. All geometrical parameters of the structure are optimized simultaneously by means of surrogate based optimization involving variable-fidelity...
-
SYMULACJA SZEROKOPASMOWEGO GENERATORA SYGNAŁÓW ZAKŁÓCAJĄCYCH DLA POTRZEB OCHRONY PRZED RC-IED
PublicationReferat został poświęcony symulacji działania generatora zakłóceń szerokopasmowych z uwzględnieniem efektów występujących w rzeczywistym urządzeniu i determinujących kształt widma nadawanego sygnału. W artykule zawarto podstawowe informacje dotyczące projektu Aegis, w ramach którego powstaje mobilny generator kurtyny EM. Następnie opisano przyjęty model symulacyjny, uwzględniający czynniki warunkujące postać sygnału na wyjściu...
-
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.
-
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.
-
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.
-
Hostility bias or sadness bias in excluded individuals: Does anodal transcranial direct current stimulation of right VLPFC vs. left DLPFC have a mitigating effect?
PublicationExclusion has multiple adverse effects on individual’s well-being. It induces anger and hostile cognitions leading to aggressive behavior. The purpose of this study was to test whether exclusion would affect recognition of anger on ambivalent faces of the excluders. We hypothesized that exclusion would elicit more anger encoding (hostility bias) than inclusion, but this effect would be mitigated by anodal tDCS of right VLPFC...
-
Influence of LCVD technologicalparameters on propertiesof polyazomethine thin films
PublicationPurpose: The aim of this paper is to show influence of technological parameters (temperature and gas streamintensity) of low-temperature chemical vapour deposition (LCVD) on optical properties and morphology ofpolyazomethine thin films.Design/methodology/approach: Thin layers of poly (1,4-phenylene-methylenenitrilo-1,4-phenylenenitrilo-methylene) (PPI) were prepared by low temperature LCVD method with use of argon as a transport...
-
Studying of spin-coated oxad-Si properties
PublicationPurpose: The major aim of this paper was describing technical conditions of polymer thin film deposition byspin-coating techniques.Design/methodology/approach: Thin films of about nanometres thickness were prepared by spin-coatingand their properties were studied. As a material for preparing polymer thin films oxad-Si was used. The thinfilms were deposited with various spinning velocity from solution of different concentration....
-
Optical properties of polyazomethine with oxygen atom in the backbon
PublicationPurpose: The aim of this paper is to show results of optical measurement performed on poly –(1-(4-methylenephenoxy-1)phenylene-4-methylene-1.4-phenylnenitrylomethylene) (PPI2) polyazomethine thinfilms and to compare with poly - (1.4-phenylenemethylenenitrilo-1.4 phenylenenitrilomethylene) (PPI).Design/methodology/approach: Influence of oxygen atom in the polymer chain on optical properties ofpolyazomethine was investigated....