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Search results for: COMPACT MICROWAVE STRUCTURES, GEOMETRY SCALING, INVERSE MODELING, MICROWAVE DESIGN, MINIATURIZED COUPLERS, SURROGATE MODELING
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Urban flash flood hazard identification and assessment applying geospatial techniques and hydrodynamic modeling; Erbil city case study, Kurdistan Region of Iraq
PublicationThis dissertation aims to investigate the factors behind flash flooding in Erbil's central district, located in the Kurdistan Region of Iraq, and develop a methodology for assessing flood hazards in the city, despite limited data accessibility. In this thesis, each factor was investigated, including analyzing extreme precipitation events in the last two decades, including their spatial and temporal distribution of rainfall, intensity,...
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An inverse algorithm for contact heat conduction problems with an interfacial heat source based on a first-order thermocouple model
PublicationInverse problems of contact heat conduction with an interfacial heat source are common in various fields of science, engineering and technology. In this study, an algorithm for their solution is developed based on an inverse parametric optimisation method with an impulse response function describing the heat partition and contact heat transfer. A first-order thermocouple model with a time constant parameter is embedded in the impulse...
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Scaling scrum with a customized nexus framework: A report from a joint industry‐academia research project
Publicationespite a wide range of scaling frameworks available, large-scale agile transformations are not straightforward undertakings. Few organizations have structures in place that fit the predefined workflows – while once one applies an off-the-shelf framework outside of its prescribed process, guidance quickly runs out. In this paper, we demonstrate how to instantiate a method configuration process using a lightweight experimental approach...
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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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Fast Low-fidelity Wing Aerodynamics Model for Surrogate-Based Shape Optimization
PublicationVariable-fidelity optimization (VFO) can be efficient in terms of the computational cost when compared with traditional approaches, such as gradient-based methods with adjoint sensitivity information. In variable-fidelity methods, the directoptimization of the expensive high-fidelity model is replaced by iterative re-optimization of a physics-based surrogate model, which is constructed from a corrected low-fidelity model. The success...
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Atomic-Scale Finite-Element Modeling of Elastic Mechanical Anisotropy in Finite-Sized Strained Phosphorene Nanoribbons
PublicationNanoribbons are crucial nanostructures due to their superior mechanical and electrical properties. This paper is devoted to hybrid studies of the elastic mechanical anisotropy of phosphorene nanoribbons whose edges connect the terminals of devices such as bridges. Fundamental mechanical properties, including Young’s modulus, Poisson’s ratio, and density, were estimated from first-principles calculations for 1-layer, 3-layer, and...
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Miniaturized methods of sample preparation
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Miniaturized solid phase extraction
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Ultra-Compact SIRC-Based Self-Triplexing Antenna with High Isolation
PublicationAn ultra-compact self-triplexing antenna realized on a substrate-integrated rectangular cavity (SIRC) is discussed in this study. The proposed structure employs two L-shaped slots and an in-verted U-shaped slot to radiate at three independent operating frequency bands. Three 50-ohm microstrip feed lines are used to excite the radiation in these slots. The operating frequency is individually tuned using the slot size. The slot placement...
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Modeling and control of a redundantly actuated variable mass 3RRR planar manipulator controlled by a model-based feedforward and a model-based-proportional-derivative feedforward–feedback controller
PublicationIn the paper, dynamics of a complex mechatronics system is considered. A redundantly actuated planar manipulator is the base of the mechanical part of it. It is a 3RRR 1 platform based parallel manipulator. To control its trajectory, a model-based feedforward controller is employed. Three aspects are fundamental in the presented investigations. The first focus is on development of an accurate numerical model used to solve the inverse...
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Role of public space in designing complex urban structures
PublicationThe aim of this article is to present the main assumptions about design studios as held in the Faculty of Architecture at Gdańsk University of Technology (FA-GUT), Gdańsk, Poland, adapted to the development of key competencies in the urban planning of complex urban structures. One of these competencies is the design of public spaces. The main goal of the studios was to deliver knowledge of the role of public spaces in the design...
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Investigations of broadband multilayered coupled line couplers
PublicationW pracy przedstawiono dwa układy szerokopasmowych sprzęgaczy 3dB. Pierwszy układ zrealizowany jest w oparciu o linie paskowe z rowkowanym ekranem. Drugi układ to zmodyfikowany układ sprzęgacza mikrofalowego zrealizowanego w oparciu o linie mikropaskowe ze wspólną masą. Zaproponowane układy sprzęgaczy odznaczają się szerszym pasmem pracy w porównaniu do układów prezentowanych w literaturze. Wyniki symulacji układów zostały zweryfikowane...
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Multi-objective antenna design by means of sequential domain patching
PublicationA simple yet robust methodology for rapid multiobjective design optimization of antenna structures has been presented. The key component of our approach is sequential domain patching of the design space which is a stencil-based search that aims at creating a path that connects the extreme Pareto-optimal designs, obtained by means of single-objective optimization runs. The patching process yields the initial approximation of the...
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Ontological Modeling for Contextual Data Describing Signals Obtained from Electrodermal Activity for Emotion Recognition and Analysis
PublicationMost of the research in the field of emotion recognition is based on datasets that contain data obtained during affective computing experiments. However, each dataset is described by different metadata, stored in various structures and formats. This research can be counted among those whose aim is to provide a structural and semantic pattern for affective computing datasets, which is an important step to solve the problem of data...
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Lightweight structures in architecture: scenarios for the future
PublicationLightweight structures - structures with a reduced weight, which otherwise retain the qualities necessary for the building performance, ensuring a proper durability and strength, safety, indoor environmental quality and energy efficiency; stuctures which strive for the optimization of structural systems - are in tune with current trends and socio-economic, environmental and technological factors. The growing interest in the lightweight...
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A note on compact and compact circular edge-colorings of graphs
PublicationW pracy rozważamy dwa warianty kolorowania krawędzi grafów prostych i ważonych, mianowicie kolorowania zwarte oraz zwarte cyrkularne. Rozważamy relacje pomiędzy nimi. Dowodzimy, że każdy zewnętrznie planarny graf dwudzielny posiada zwarte pokolorowanie krawędziowe oraz, że problem ten dla grafów ogólnych jest NP-zupełny. Podajemy również wielomianowy 1.5-przybliżony algorytm oraz pseudowielomianowy dokładny algorytm zwartego cyrkularnego...
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Compact City na Żernikach = Compact City in Żerniki
PublicationThe paper explores the impact of the new neighbourhood built within the framework of the European Capital of Culture 2016 in Wrocław on the future development of the city.
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Evaluation of accuracy of surrogate models
PublicationArtykuł przestawia statystyczne podejście do oceny dokładności modeli zastępczych. Prezentowana jest miara dokładności bazująca na dystrybucji błędów w zbiorze testowym. Praca zawiera dyskusję na temat oceny dokładności samego modelu oraz zasadności wyboru kryterium zatrzymującego proces automatycznego tworzenia modelu.
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Optimalization of TiO2 nanotube geometry using fuzzy reasoning approach
PublicationThe geometry of TiO2 nanotube layer on titanium, obtained by electrochemical anodization, has been determined by using fuzzy reasoning approach. A proposed method showed the possibility of nanotube array architecture optimization by choosing an appropriate anodization condition. A fuzzy logic controller (FLC) was utilized using Matlab Software.
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RANS-based design optimization of dual-rotor wind turbines
PublicationPurpose An improvement in the energy efficiency of wind turbines can be achieved using dual rotors. Because of complex flow physics, the design of dual-rotor wind turbines (DRWTs) requires repetitive evaluations of computationally expensive partial differential equation (PDE) simulation models. Approaches for solving design optimization of DRWTs constrained by PDE simulations are investigated. The purpose of this study is to determine...
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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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An Implementation of a Compact Smart Resistive Sensor Based on a Microcontroller with an Internal ADC
PublicationIn the paper a new implementation of a compact smart resistive sensor based on a microcontroller with internal ADCs is proposed and analysed. The solution is based only on a (already existing in the system) microcontroller and a simple sensor interface circuit working as a voltage divider consisting of a reference resistor and the resistive sensor connected in parallel with an interference suppression capacitor. The measurement...
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Compact 4 × 4 butler matrix with non‐standard phase differences for IoT applications
PublicationButler matrices represent a popular class of feeding networks for antenna arrays. Large dimensions and the lack of flexibility in terms of achievable output phase difference make conventional Butler structures of limited use for modern communication devices. In this work, a compact planar 4 × 4 matrix with non-standard relative phase shifts of –30º, 150º, –120º, and 60º has been proposed. The structure is designed to operate at...
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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...
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Minimal surfaces and conservation laws for bidimensional structures
PublicationWe discuss conservation laws for thin structures which could be modeled as a material minimal surface, i.e., a surface with zero mean curvatures. The models of an elastic membrane and micropolar (six-parameter) shell undergoing finite deformations are considered. We show that for a minimal surface, it is possible to formulate a conservation law similar to three-dimensional non-linear elasticity. It brings us a path-independent...
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Computer-aided evaluation of the railway track geometry on the basis of satellite measurements
PublicationIn recent years, all over the world there has been a period of intensive development of GNSS (Global Navigation Satellite Systems) measurement techniques and their extension for the purpose of their applications in the field of surveying and navigation. Moreover, in many countries a rising trend in the development of rail transportation systems has been noticed. In this paper, a method of railway track geometry assessment based...
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Physical modeling in sands in a wide range of stress level: Application to the calibration of CPTU i DMT tests.
PublicationPraca dotyczy badań modelowych w gruntach niespoistych ze szczególnym uwzględnieniem wpływu wysokiego poziomu naprężenia na zachowanie się podłoża gruntowego. Praca składa się z siedmiu rozdziałów. W pierwszym z nich opisano zachowanie się piasku w szerokim zakresie naprężeń z uwzględnieniem ściśliwości, kruszenia się ziaren, nieliniowości obwiedni zniszczenia oraz nieliniowości modułu odkształcenia związanych z poziomem naprężenia...
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Fast EM-driven size reduction of antenna structures by means of adjoint sensitivities and trust regions
PublicationIn this letter, a simple yet robust and computationally efficient optimization technique for explicit size reduction of antenna structures is presented. Our approach directly handles the antenna size as the main design objective, while ensuring satisfactory electrical performance by means of suitably defined penalty functions. For the sake of accuracy, the antenna structure is evaluated using high-fidelity EM simulation. In order...
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Inverse Potassium Hydride: A Theoretical Study
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Inverse Sodium Hydride: A Theoretical Study
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Microwave plasma treatment of simulated biomass syngas: Interactions between the permanent syngas compounds and their influence on the model tar compound conversion
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Pharmacological Profile and Molecular Modeling of Cyclic Opioid Analogues Incorporating Various Phenylalanine Derivatives
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Application of Bayesian Multilevel Modeling in the Quantitative Structure–Retention Relationship Studies of Heterogeneous Compounds
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Population Modeling of Filgrastim PK-PD in Healthy Adults Following Intravenous and Subcutaneous Administrations
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Numerical and physical modeling of water flow over the ogee weir of the new Niedów barrage
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Determination of Complex Permeability of Silicon Steel for Use in High-Frequency Modeling of Power Transformers
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<title>Modeling of broadband light source to use with optical coherent tomography system</title>
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Genre-Based Music Language Modeling with Latent Hierarchical Pitman-Yor Process Allocation
PublicationIn this work we present a new Bayesian topic model: latent hierarchical Pitman-Yor process allocation (LHPYA), which uses hierarchical Pitman-Yor pr ocess priors for both word and topic distributions, and generalizes a few of the existing topic models, including the latent Dirichlet allocation (LDA), the bi- gram topic model and the hierarchical Pitman-Yor topic model. Using such priors allows for integration of -grams with a topic model,...
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Decisional DNA for modeling and reuse of experiential clinical assessments in breast cancer diagnosis and treatment
PublicationClinical Decision Support Systems (CDSS) are active knowledge resources that use patient data to generate case specific advice. The fast pace of change of clinical knowledge imposes to CDSS the continuous update of the domain knowledge and decision criteria. Traditional approaches require costly tedious manual maintenance of the CDSS knowledge bases and repositories. Often, such an effort cannot be assumed by medical teams, hence...
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Numerical modeling of cross-flow heat exchanger for air-conditioning purposes in preliminary study.
PublicationPraca przedstawia wyniki obliczeń numerycznych krzyżowego płytowo-rurowego wymiennika ciepła przeznaczonego do celów klimatyzacyjnych w początkowym etapie jego projektowania.
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Modeling the electrical characteristics of P3HT:PCBM bulk heterojunction solar cells: Influence of the interface recombination
PublicationThe interface recombination of charge carriers located in the material with lower permittivity (Szmytkowski 2009 Chem.Phys.Lett. 470 123) has been implemented for the first time to calculate the electrical characteristics of the donor-acceptor P3HT:PCBM bulk heterojunction solar cell. In order to estimate the photocurrent density in this system, a simple analytical formula has been derived. We have obtained a very good agreement...
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Computing internodal conductivities in numerical modeling of two dimensional unsaturated flow on rectangular grid
PublicationW artykule porównano rozwiązania numeryczne dwuwymiarowego równania przepływu nienasyconego z użyciem różnych metod uśredniania współczynnika przewodności hydraulicznej między sąsiednimiwęzłami. Uwzględniono średnia arytmetyczną, geometryczną, "pod prad" oraz całkową, a także niedawno zaproponowany sposób uśredniania oparty na analizie przepływu ustalonego. Ten ostatni sposób okazałsię najbardziej uniwersalny, gdyż umożliwiał otrzymanie...
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Smart modeling support for managing complexities and dynamics of knowledge-based systems - part 2
PublicationPrzedstawiono i poddano analizie najnowsze trendy w zakresie kierunków badań dotyczących inteligentnego wspomagania zarządzania dynamiką i kompleksowością systemów opartych na wiedzy.
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Improvement of the Rhizoremediation efficiency of PAHs contaminated soil under cysteine treatment along with modeling
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Accurate modeling of layout parasitic to forecast EMI emitted from a DC-DC converter.
PublicationThis paper illustrates how to account for all parasitic due to the layout of a power converter (inductive and capacitive), in order to forecast electromagnetic interferences (EMI). The method is generic, and is validated here in the simple example of a DC-DC converter, realized on different technologies: insulated metal substrate (IMS), printed circuit board (PCB). In addition, several layouts aspects will be investigated. Conclusions...
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Modelowanie hydraulicznych skutków katastrofy zapory wodnej. Modeling of dam-break water flow
PublicationPrzedstawiono numeryczne rozwiązanie równań przepływu wody płytkiej wywołanego katastrofą zapory wodnej. Przestrzenną dyskretyzację równań wykonano metodą objętości skończonych. Metodę zastosowano do prognostycznych obliczeń propagacji fali wezbraniowej wywołanej katastrofą zapory wodnej w dolinie rzeki Toce. Wyniki obliczeń porównano z dostępnymi (obcymi) pomiarami wykonanymi na fizycznym modelu doliny. Uzyskano zadowalającą...
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NOx emission from a two-stroke ship engine. Part 1: Modeling aspect
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Submerged objects modeling and storing in a global reference context using multiresolution spline technique,
PublicationContemporary records from multibeam sonars or even elevations from 3D shuttle radar topography missions feature high resolution. On the other hand, bathymetric models of a different resolution from different sensors are available as well, beginning from very high resolution MBS records and low resolution records coming from regular scattered measurements. Approximating and eventually visualizing the high volume scattered 3D raster...
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Genre-Based Music Language Modeling with Latent Hierarchical Pitman-Yor Process Allocation
PublicationIn this work we present a new Bayesian topic model: latent hierarchical Pitman-Yor process allocation (LHPYA), which uses hierarchical Pitman-Yor pr ocess priors for both word and topic distributions, and generalizes a few of the existing topic models, including the latent Dirichlet allocation (LDA), the bi- gram topic model and the hierarchical Pitman-Yor topic model. Using such priors allows for integration of -grams with a topic...
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Sparse vector autoregressive modeling of audio signals and its application to the elimination of impulsive disturbances
PublicationArchive audio files are often corrupted by impulsive disturbances, such as clicks, pops and record scratches. This paper presents a new method for elimination of impulsive disturbances from stereo audio signals. The proposed approach is based on a sparse vector autoregressive signal model, made up of two components: one taking care of short-term signal correlations, and the other one taking care of long-term correlations. The method...