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Search results for: CRF
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LED Light Sources and Their Complex Set-Up for Visually and Biologically Effective Illumination for Ornamental Indoor Plants
PublicationOrnamental plants are often used in indoor environments as part of biophilic design to improve the health and wellbeing of occupants, and to support sustainable, green architecture. Unfortunately, many plants do not thrive and need to be continuously replaced, which is economically unsustainable. The wavelengths and spectrum ratio of commonly used light sources such as light emitting diode (LED), and the lack of an appropriate...
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Multiple transcriptional factors regulate transcription of the rpoE gene in Escherichia coli under different growth conditions and when the lipopolysaccharide biosynthesis is defective.
PublicationThe RpoE sigma factor is essential for the viability of Escherichia coli. RpoE regulates extracytoplasmic functions including lipopolysaccharide (LPS) translocation and some of its non-stoichiometric modifications. Transcription of the rpoE gene is positively autoregulated by EσE and by unknown mechanisms that control the expression of its distally located promoter(s). Mapping of 5′ ends of rpoE mRNA identified five new transcriptional...
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The effect of metal cluster deposition route on structure and photocatalytic activity of mono- and bimetallic nanoparticles supported on TiO2 by radiolytic method
PublicationTiO2 (P25) was modified with small and relatively monodisperse mono- and bimetallic clusters (Ag, Pd, Pt, Ag/Pd, Ag/Pt and Pd/Pt) induced by radiolysis to improve its photocatalytic activity. The as-prepared samples were characterized by X-ray fluorescence spectrometry (XRF), photoluminescence spectrometry (PL), diffuse reflectance spectroscopy (DRS), X-ray powder diffractometry (XRD), scanning transition electron microscopy (STEM)...
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Comparison of Tire Rolling Resistance Measuring Methods for Different Surfaces
PublicationThe rolling resistance of car tires is one of the most important parameters characterizing tires today. This resistance has a very significant contribution to the energy consumption of wheeled vehicles. The climate crisis has forced tire and car manufacturers to place great emphasis on the environmental impact of their products. Paradoxically, the development of electric vehicles has led to an even greater importance of rolling...
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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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Dissociative ionization dynamics of dielectric gas C3F7CN
PublicationFluoronitrile C3F7CN is a promising candidate for the replacement of SF6 dielectric gas in high-voltage insulation. We present a combined experimental and theoretical study on its ionization dynamics probed in the 0-100 eV energy range. We exploited the total ion collection technique to determine the absolute ionization cross section, mass spectrometry to determine the fragment branching ratios and ab initio nonadiabatic molecular...
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Host and pathogen factors in Klebsiella pneumoniae upper urinary tract infections in renal transplant patients
PublicationPurpose . To analyse the role of virulence factors (VFs) and host in Klebsiella pneumoniae upper urinary tract infections (UTIs) in renal transplant (RTx) recipients. Methodology. Clinical and demographic data were registered prospectively. Phylogenetic background of K. pneumoniae isolates was analysed by PCR melting profiles (MP) and the following VFs genes: fimH-1, uge, kpn, ycfM, mrkD, rmpA, magA, hlyA, cnf-1, irp-1, irp-2,...
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Fracture in Asymmetric Bonded Joints
PublicationAdhesion was studied in asymmetric bonded joints using fracture mechanics tests. The asymmetric bonded joints consist of two different type and/or thickness materials bonded by an adhesive. Mentions of asymmetric bonded joint tests employed so far are rare in the literature. They are imperfect and therefore are not standardized. Accordingly three new tests were introduced in this work to study bonded joints. The new metrological...
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A Multi Rig Screening Test for Thin Ceramic Coatings in Bio - Tribological Applications
PublicationA method is presented for the comparative testing of wear resistance of ceramic coatings made from materials potentially feasible in tribo - medical applications, mainly orthopaedic implants made from ceramics coated metals for low cost, long life and low wear particle emission into the body. The method was devised as the main tool for use in research and is comprised of flat on flat and ball on flat surface (sliding) tests. Seven...
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Progress in ATRP-derived materials for biomedical applications
PublicationThe continuing wave of technological breakthroughs and advances is critical for engineering well- defined materials, particularly biomaterials, with tailored microstructure and properties. Over the last few decades, controlled radical polymerization (CRP) has become a very promising option for the synthesis of precise polymeric materials with an unprecedented degree of control over mo lecular architecture. Atom transfer radical...
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Micro‑ and nano‑ bentonite to improve the strength of clayey sand as a nano soil‑improvement technique
PublicationNano-additives results in the formation of nano-cementation (NC). This process is recently used to improve the durability of various building materials. NC used to improve the strength of untreated soil materials, also known as nano soil-improvement (NSI). In few years, the role of nano-additives in various types of soils were developed. In this research, the role of micro- and nano- size of bentonite as soil stabilizer was evaluated...
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The role of the One-Belt One-Road initiative in China's exports and global value chains
PublicationResearch background: China is regarded as the “world factory” highly involved in international trade and plays an increasingly important role in the global value chains (GVC). Additionally, the “One-Belt One-Road” (OBOR) initiative was proposed by the Chinese government to further promote China in the international market. Purpose of the article: The article explores the role of the OBOR in China’s exports and global value...
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Magnetic field maps of an astable multivibrator in frequency range from 30 MHz to 3 GHz – spatial detection
Open Research DataThe data presents a result of near field measurements of electromagnetic emissions radiated from the PCB of a small electronic device. An efficient method of modelling the magnetic and electric field emissions is the measurements in the near field using electric and magnetic probes. The attached files contain magnetic field maps created on based measurements...
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Speciation of heavy metals in bottom sediments of drinking water reservoir for Gdansk, Poland – changes over the 14 years
PublicationThere was conducted a comparative study of the concentrations of heavy metals (Zn, Cu, Pb, and Cd) in the surface layer of sediments collected in two investigation periods: 1999–2000 and 2013. Theresults demonstrated that the degree of metals pollution decreased over time. The contamina-tion factors (Cf) calculated for Zn, Cu, Pb, and Cd were respectively 3.63, 3.86, 3.23, and 3.25 in the first period of research and 1.35, 3.42,...
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Magnetic field maps of an astable multivibrator in frequency range from 30 MHz to 3 GHz – selective detection
Open Research DataThe data presents a result of near field measurements of electromagnetic emissions radiated from the PCB of a small electronic device. An efficient method of modelling the magnetic and electric field emissions is the measurements in the near field using electric and magnetic probes. The attached files contain magnetic field maps created on based measurements...
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Increased inspiratory resistance affects the dynamic relationship between blood pressure changes and subarachnoid space width oscillations
PublicationBackground and objective Respiration is known to affect cerebrospinal fluid (CSF) movement. We hypothesised that increased inspiratory resistance would affect the dynamic relationship between blood pressure (BP) changes and subarachnoid space width (SAS) oscillations. Methods Experiments were performed in a group of 20 healthy volunteers undergoing controlled intermittent Mueller Manoeuvres (the key characteristic of the procedure...
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Development of fragility curves in adjacent steel moment-resisting frames considering pounding effects through improved wavelet-based refined damage-sensitive feature
PublicationFragility curves present useful information related to earthquake-induced probability assessment of steel moment-resisting frames (MRFs) and determine the probability of the damage exceedance at different floor levels of MRFs. The review of the literature shows that most of the previous studies dealing with the fragility curves were based on conventional measures, such as spectral acceleration at the first mode period, peak...
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Antibiotic resistance, virulence, and phylogenetic analysis of Escherichia coli strains isolated from free-living birds in human habitats
PublicationWild birds can be colonized by bacteria, which are often resistant to antibiotics and have various virulence profiles. The aim of this study was to analyze antibiotic resistance mechanisms and virulence profiles in relation to the phylogenetic group of E. coli strains that were isolated from the GI tract of wildfowl. Out of 241 faecal samples, presence of E. coli resistant to a cephalosporin (ESBL/AmpC) was estimated for 33 isolates...
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AFM analysis of duplex steel structure and composition
Open Research DataDue to the high content of alloying elements, duplex stainless steels are characterized by a complex structure of phase transitions. Among all types of intermetallic compounds, the sigma phase is of major interest due to its detrimental effect on both mechanical properties and corrosion behavior. It is an intermetallic phase enriched in Cr and Mo and...
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Speciation of heavy metals in bottom sediments of a drinking water reservoir for Gdańsk, Poland – changes over the 14 years
PublicationThere was conducted a comparative study of the concentrations of heavy metals (Zn, Cu, Pb, andCd) in the surface layer of sediments collected in two investigation periods: 1999–2000 and 2013.The results demonstrated that the degree of metals pollution decreased over time. The contaminationfactors (Cf) calculated for Zn, Cu, Pb, and Cd were respectively 3.63, 3.86, 3.23, and 3.25 in thefirst period of...
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Compression test results of fused filamend fabricated polylactyde and polylactyde with carbon fiber filler
Open Research DataThe DataSet contains the results of the mechanical behaviour of cube specimens with dimensions 30 x 30 x 30 cm3. The specimens were additively manufactured with the fused filament fabrication (FFF) method. They used two different materials polylactide (PURE PLA) and polylactide with carbon fibre filler (PLA+CF). The specimens were segregated into three...
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Regulated assembly of lipopolysaccharide and sensing of its alterations in Escherichia coli
PublicationThis thesis describes mechanism of the regulation of the transcription of the rpoE gene encoding an essential RNA polymerase subunit in Escherichia coli. The RpoE regulates extracytoplasmic stress response regulon and is required to initiate transcription of genes, whose products are involvedin the folding of periplasmic proteins and synthesis and transport of outer membrane components. The transcriptional regulation of the rpoE...
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Chemical investigation on the mechanism and kinetics of the atmospheric degradation reaction of Trichlorofluoroethene by OH⋅ and Its subsequent fate in the presence of O2/NOx
PublicationThe M06-2X/6-311++G(d,p) level of theory was used to examine the degradation of Trichlorofluoroethene (TCFE) initiated by OH⋅ radicals. Additionally, the coupled-cluster single-double with triple perturbative [CCSD(T)] method was employed to refine the single-point energies using the complete basis set extrapolation approach. The results indicated that OH-addition is the dominant pathway. OH⋅ adds to both the C1 and C2 carbons,...
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Music Information Retrieval – Soft Computing versus Statistics . Wyszukiwanie informacji muzycznej - algorytmy uczące versus metody statystyczne
PublicationMusic Information Retrieval (MIR) is an interdisciplinary research area that covers automated extraction of information from audio signals, music databases and services enabling the indexed information searching. In the early stages the primary focus of MIR was on music information through Query-by-Humming (QBH) applications, i.e. on identifying a piece of music by singing (singing/whistling), while more advanced implementations...
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Kontrola jakości i analityka techniczna [Moduł dyscyplinarny, grupa B]
e-Learning CoursesProwadzący: Dr hab. inż. Grzegorz Boczkaj prof. PG Terminy realizacji: 25 marca, 1 kwietnia, 15 kwietnia, 22 kwietnia, 13 maja w godz. od 09:15 do 12-tej /zajęcia online Tematyka realizowanego przedmiotu obejmuje: Pobieranie próbek do badań (on-line, off-line, at-line, in-line) Przygotowanie próbek do badań (techniki i przykłady metodyk dla próbek stałych, ciekłych i gazowych) Techniki i wybrane metodyki klasyczne (miareczkowanie,...
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Application of shifted Chebyshev polynomial-based Rayleigh–Ritz method and Navier’s technique for vibration analysis of a functionally graded porous beam embedded in Kerr foundation
PublicationPresent study is dealt with the applicability of shifted Chebyshev polynomial based Rayleigh-Ritz method and Navier’s technique on free vibration of Functionally Graded (FG) beam with uniformly distributed porosity along the thickness of the beam. The material properties such as Young’s modulus, mass density, and Poisson’s ratio are also considered to vary along the thickness of the FG beam as per the power-law exponent model....
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The Impact of Direct Normal Irradiation on the Solar Tower Power Plant Performance based on Real and Satellite Data: Analysis on Algerian Regions
PublicationThe present paper presents a deep study on the possibility of implementing Concentrated Solar Power (CSP) plants in Algeria for the production of the electrical energy. Indeed, this paper focusses mainly on the main parameters, which can have an important impact on the choice of the location, the dimension and the available thermal energy storage system. In this study, three main parameters are investigate...
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Caffeine Inhibits Differentiation Of Lung Cancer Stem Cells By Modulating Their Respiratory Metabolism
PublicationIt is ell established that many tumor types contain a fraction of cells, with stem cell-like properties, called cancer stem cells (CSCs), that are resistant to apoptosis induced by therapeutic agents. The presence of CSCs may explain why a standard anticancer treatment, that eliminates only differentiated cancer cells, does not lead to cancer cure.We previously showed the existence of caffeine-sensitive mechanism that controls...
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Technologie szczelinowania w eksploatacji gazu z łupków – predykcja składu płynu pozabiegowego
PublicationNiniejsza rozprawa składa się z dwóch głównych części: literaturowej i doświadczalnej. W części literaturowej przedstawiono modele literaturowe dotyczące płynu pozabiegowego. Wskazano, że dobrze opisane zostały modele wykorzystujące dane dotyczące płynu pozabiegowego do optymalizacji oczyszczania odwiertu i zwiększania produkcji. Modele nawiązujące do przedmiotu dysertacji są nieliczne, ograniczone do danych na wybranych formacjach....
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The values of Permutation Entropy for individuals with Normal Sinus Rhythm
Open Research DataThe dataset consists of calculated values of entropy of 75 000 intervals between consecutive heartbeats (RR intervals) for 54 patients with normal sinus rhythm (NSR). The original data were taken from PhysioNet Normal Sinus Rhythm RR Interval Database (cf. Goldberger A., Amaral L., Glass L., Hausdorff J., Ivanov P.C., Mark R., Mietus J.E., Moody G.B.,...
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Spinels in the Cu-Mn-(Fe, Ni, Zn, Cr)-O system: synthesis, studies of structure, physicochemical properties, and operando electrocatalytic activity
ProjectsProject realized in Katedra Inżynierii Materiałów Funkcjonalnych WETI according to UMO-2022/45/N/ST5/03627 agreement from 2023-01-17
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Model Pomorskiej Nagrody Jakości w świetle wyników badań opinii stron zainteresowanych
PublicationCel - prezentacja oryginalnego modelu wykorzystywanego do oceny/samooceny organizacji w regionalnym konkursie o Pomorską Nagrodę Jakości na podstawie oceny dotychczasowych doświadczeń oraz badania opinii i potrzeb głównych interesariuszy tej inicjatywy. Podstawowym założeniem przy opracowaniu tego modelu jest jego dostosowanie do współczesnych trendów dotyczących doskonałości organizacyjnej oraz upowszechnienie jego stosowania...
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The values of Block Entropy for individuals with Normal Sinus Rhythm
Open Research DataThe dataset consists of calculated values of entropy of 75 000 intervals between consecutive heartbeats (RR intervals) for 54 patients with normal sinus rhythm (NSR). The original data were taken from PhysioNet Normal Sinus Rhythm RR Interval Database (cf. Goldberger A., Amaral L., Glass L., Hausdorff J., Ivanov P.C., Mark R., Mietus J.E., Moody G.B.,...
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Tensile test results of fused filamend fabricated polylactyde and polylactyde with carbon fiber filler
Open Research DataThe Dataset contains the results of the mechanical behaviour of dog-bone shaped specimens. The specimens were additively manufactured with the fused filament fabrication (FFF) method. They used two different materials polylactide (PURE PLA) and polylactide with carbon fibre filler (PLA+CF). The specimens were segregated into three groups - unsterilized,...
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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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Analysis of circular polarization antenna design trade‐offs using low‐cost EM‐driven multiobjective optimization
PublicationCircular polarization (CP) antennas are vital components of modern communication systems. Their design involves handling several requirements such as low reflection and axial ratio (AR) within the frequency range of interest. Small size is an important criterion for antenna mobility which is normally achieved as a by‐product of performance‐oriented modifications of the structure topology. In this work, multiobjective optimization...
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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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Multi-objective design optimization of antennas for reflection, size, and gain variability using kriging surrogates and generalized domain segmentation
PublicationCost-efficient multi-objective design optimization of antennas is presented. The framework exploits auxiliary data-driven surrogates, a multi-objective evolutionary algorithm for initial Pareto front identification, response correction techniques for design refinement, as well as generalized domain segmentation. The purpose of this last mechanism is to reduce the volume of the design space region that needs to be sampled in order...
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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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Reduced-cost surrogate modeling of input characteristics and design optimization of dual-band antennas using response features
PublicationIn this article, a procedure for low-cost surrogate modeling of input characteristics of dual-band antennas has been discussed. The number of training data required for construction of an accurate model has been reduced by representing the antenna reflection response to the level of suitably defined feature points. The points are allocated to capture the critical features of the reflection characteristic, such as the frequencies...
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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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Recent advances in rapid multiobjective optimization of expensive simulation models in microwave and antenna engineering by Pareto front exploration
PublicationPractical engineering design problems are inherently multiobjective, that is, require simultaneous control of several (and often conflicting) criteria. In many situations, genuine multiobjective optimization is required to acquire comprehensive information about the system of interest. The most popular solution techniques are populationbased metaheuristics, however, they are not practical for handling expensive electromagnetic...
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Generalized Pareto ranking bisection for computationally feasible multi-objective antenna optimization
PublicationMulti-objective optimization (MO) allows for obtaining comprehensive information about possible design trade-offs of a given antenna structure. Yet, executing MO using the most popular class of techniques, population-based metaheuristics, may be computationally prohibitive when full-wave EM analysis is utilized for antenna evaluation. In this work, a low-cost and fully deterministic MO methodology is introduced. The proposed generalized...
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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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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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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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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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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...