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Mechanical properties of mosquito nets in the context of hernia repair
PublicationThe paper deals with issue of applying mosquito nets as implants in hernia repair, which have already been used in resource-poor developing countries. Uniaxial tensile tests have been conducted on polyester mosquito meshes in two orthogonal directions. Non-linear elastic constitutive laws parameters have been identified to be applied in dense net material models. Mechanical performance of tested mosquito nets has been compared...
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DFT-based prediction of reactivity of short-chain alcohol dehydrogenase
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A pore-scale thermo–hydro-mechanical model for particulate systems
PublicationA pore scale numerical method dedicated to the simulation of heat transfer and associated thermo–hydro-mechanical couplings in granular media is described. The proposed thermo–hydro-mechanical approach builds on an existing hydromechanical model that employs the discrete element method for simulating the mechanical behavior of dense sphere packings and combines it with the finite volume method for simulating pore space fluid flow...
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Metoda chromatyczna i jej zastosowania techniczne
PublicationArtykuł ma charakter przeglądowy. Przedstawiono w nim najważniejsze modele koloryzowania grafów i ich zastosowania w wybranych problemach technicznych. Ponieważ jest to wiodąca tematyka badawcza Katedry Podstaw Informatyki Wydziału ETI Politechniki Gdańskiej, praca służy również upowszechnianiu dorobku naukowego pracowników Katedry oraz osób z nią współpracujących w opisywanej dziedzinie.
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A simple and efficient hybrid discretization approach to alleviate membrane locking in isogeometric thin shells
PublicationThis work presents a new hybrid discretization approach to alleviate membrane locking in isogeometric finite element formulations for Kirchhoff–Love shells. The approach is simple, and requires no additional dofs and no static condensation. It does not increase the bandwidth of the tangent matrix and is effective for both linear and nonlinear problems. It combines isogeometric surface discretizations with classical Lagrange-based...
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Behaviour of orthotropic surgical implant in hernia repair due to the material orientation and abdomen surface deformation
Publicationrelation to the different range of typical deformations observed in different directions and zones of abdomen surface due to the patients’ life activities, has a significant influence on the extreme junction forces in the mesh–tissue connections and hence the repair persistence. The finite element model of the orthotropic implant was developed, and the junction forces in the connections of tissue and mesh were studied. The kinematical...
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Mathematical modelling of implant in an operated hernia for estimation of the repair persistence
PublicationThis paper presents mathematical modelling of an implanted surgical mesh used in the repair process of the abdominal hernia. The synthetic implant is simulated by a membrane structure. The author provides a material modelling of the implant based on the dense net model appropriate for technical fabrics. The accuracy of the proposed solution is evaluated by comparing the simulations of the dynamic behaviour of the system with the...
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A selectively reduced degree basis for efficient mixed nonlinear isogeometric beam formulations with extensible directors
PublicationThe effect of higher order continuity in the solution field by using NURBS basis function in isogeometric analysis (IGA) is investigated for an efficient mixed finite element formulation for elastostatic beams. It is based on the Hu–Washizu variational principle considering geometrical and material nonlinearities. Here we present a reduced degree of basis functions for the additional fields of the stress resultants and strains...
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Active Kriging-based conjugate first-order reliability method for highly efficient structural reliability analysis using resample strategy
PublicationEfficient structural reliability analysis method is crucial to solving reliability analysis of complex structural problems. High-computational cost and low-failure probability problems greatly limit the efficiency in structural reliability analysis problems, causing the safety and reliability of the structure to be questioned. In this work, a highly efficient structural reliability analysis method coupling active Kriging algorithm...
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Chained machine learning model for predicting load capacity and ductility of steel fiber–reinforced concrete beams
PublicationOne of the main issues associated with steel fiber–reinforced concrete (SFRC) beams is the ability to anticipate their flexural response. With a comprehensive grid search, several stacked models (i.e., chained, parallel) consisting of various machine learning (ML) algorithms and artificial neural networks (ANNs) were developed to predict the flexural response of SFRC beams. The flexural performance of SFRC beams under bending was...
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Paweł Lubomski dr inż.
PeoplePaweł Lubomski is the director of the IT Services Centre at the Gdańsk University of Technology. He is responsible for developing and maintaining the central information systems of the university. He is also in charge of the R&D team and works on new approaches to IT systems’ protection. He also acts as the project manager of two big innovative IT projects co-financed by the European Funds. He received a PhD degree in computer...
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Leszek Zięba mgr inż.
PeopleHe is a graduate of the Faculty of Electronics (1979 M.Sc. Electronics majoring in Computer Science). In the years 1979-1994 he worked at the PG Computing Center as a senior programmer, chief technologist in the Department of Basic Software and Software Development Department, senior designer. From 1994, he was employed as a senior lecturer in the Department of Production Engineering at the Faculty of Management and Economics of...
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Sea ice floe size and shape data from a very high resolution satellite image (Knox Coast, East Antarctica)
Open Research DataThis dataset contains floe size distribution data from a very high resolution (pixel size: 0.3 m) optical satellite image of sea ice, acquired on 16. Feb. 2019 off the Knox Coast (East Antarctica). The image shows relatively small ice floes produced by wave-induced breakup of landfast ice between the Mill Island and Bowman Island. The ice floes are...
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The chemical and mechanical pressure influence on chromium luminescence
Open Research DataIn this study, we aim to compare the changes in the luminescence properties of Ga2O3:Cr3+ modified by Al or Sc ion substitution (chemical pressure) and hydrostatic pressure. We find the same behavior for Ga2–xAlxO3:Cr3+ and different behavior for Ga2–xScxO3:Cr3+ in terms of the optical properties under chemical and mechanical pressure. We consider Al...
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Identification and cloning of C. albicans SC5314 genes encoding L-methionine biosynthetic pathway enzymes.
Open Research DataEnzymes of fungal L-methionine biosynthetic pathway: homoserine O-acetyltransferase (Met2p), O-acetylhomoserine sulfhydrylase (Met15p) and cystathionine-γ-synthase (Str2p) could be exploited as molecular targets for antifungal chemotherapy. The goal of the study was to identify and clone genes encoding mentioned above enzymes. MET2, MET15 and STR2 genes...
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The luminescence study of LiGa5(1−x)O8:5xCr3+ coumpounds
Open Research DataInfrared luminescent materials have evoked much attention from chemists and material scientists. Although substantial progress is made in materials design, the luminescent mechanism remains ambiguous in the complex structures, presenting major barriers to developing novel infrared luminescent materials. Herein, this study aims to deliberate a complete...
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The effect of pH change of ketoprofen solutions on the germination of Sorghum bicolor (sorghum) seeds
Open Research DataIn these studies, an attempt was also made to determine whether (and, if so, to what extent) the change in pH affects the toxicity of ketoprofen will affect the germination of Sorghum bicolor (sorghum) seeds. As reported by Kudlak B, Wieczerzak M, Yotova G, Tsakovski S, Simeonov V, Namieśnik J (2016) Environmental risk assessment of Polish wastewater...
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Karolina Lademann mgr
PeopleCurriculum vitae
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Paweł Rościszewski dr inż.
PeoplePaweł Rościszewski received his PhD in Computer Science at Gdańsk University of Technology in 2018 based on PhD thesis entitled: "Optimization of hybrid parallel application execution in heterogeneous high performance computing systems considering execution time and power consumption". Currently, he is an Assistant Professor at the Faculty of Electronics, Telecommunications and Informatics, Gdańsk University of Technology, Poland....
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Igor Garnik dr inż.
PeopleIgor Garnik graduated from the Faculty of Electronics at the Gdańsk University of Technology (1992). He works at the Gdańsk University of Technology since 1997 - first employed as an assistant in the Department of Ergonomics and Maintenance of Technical Systems at the Faculty of Management and Economics, and then - after obtaining the degree of doctor in 2006 as an assistant professor. In the years 2009–2015 he was the coordinator...
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Network-aware Data Prefetching Optimization of Computations in a Heterogeneous HPC Framework
PublicationRapid development of diverse computer architectures and hardware accelerators caused that designing parallel systems faces new problems resulting from their heterogeneity. Our implementation of a parallel system called KernelHive allows to efficiently run applications in a heterogeneous environment consisting of multiple collections of nodes with different types of computing devices. The execution engine of the system is open for...
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Dynamic Re-Clustering Leach-Based (Dr-Leach) Protocol for Wireless Sensor Networks
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Jakub Jabłoński inż.
PeopleEducation In 2016 Jakub Jabłoński finished Zbigniew Herbert XX High School in Gdańsk (math-physics-IT profile). In 2017 he started an undergraduate course in Civil Engineering at the Faculty of Civil and Environmental Engineering of the Gdańsk University of Technology, which he graduated in 2021 with the title of Bachelor of Science in Engineering. During his studies he took active part in the scientific association "Hevelius". Employment About...
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Elsa Estevez dr
PeopleElsa Estevez is the chair holder of the UNESCO Chair on Knowledge Societies and Digital Governance at Universidad Nacional del Sur, an Independent Researcher at the National Council of Scientific and Technical Research (CONICET), and a Full Professor at the National University of La Plata, all in Argentina. She is also a consultant for the Inter-American Development Bank (IADB) on matters of digital government, particularly in...
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Hackathon HackVision
EventsJuż 4 listopada o 10:00 na Politechnice Gdańskiej (aula w budynku Wydziału Inżynierii Mechanicznej i Okrętownictwa – nr 40) rozpocznie się hackathon Hackvision – wydarzenie skierowane do studentów i doktorantów.
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Ryszard Jan Barczyński dr hab. inż.
PeopleRyszard Jan Barczyński (b. 24 June 1957 in Gdańsk), Polish scientist, engineer, a specialist in solid state physics and electronic measurement techniques. In 1976, he obtained a high school diploma in the IV High School Tadeusz Kosciuszko in Torun. Higher education he graduated in 1981 at the Institute of Physics, Technical University of Gdansk in specialty of solid state physics, obtaining master's degree in engineering. Since...
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Nina Rizun dr
PeopleNina Rizun is an assistant professor at the Faculty of Management and Economics at the Gdańsk University of Technology. In October 1999 she obtained a PhD degree in technical sciences in the Faculty of Enterprise Economy and Production Organization, National Mining Academy, Dnipropetrovsk, Ukraine. PhD thesis title: Development of Complex Subsystem of the Organization and Planning of Mining and Transport Processes. In the years...
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Andrzej Klimczuk
PeopleAndrzej Klimczuk, PhD, a sociologist and public policy expert, assistant professor in the Department of Social Policy of the Collegium of Socio-Economics at the SGH Warsaw School of Economics, Poland. Editor and correspondent of publications about computer and video games in the years 2002-2009. In 2011-2013, Vice President of the Foundation's Laboratory Research and Social Action "SocLab." External expert of institutions such...
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Anna Wałek dr
PeopleDr Anna Wałek, President of IATUL – International Association of University Libraries, director of the Gdańsk University of Technology Library. An experienced library manager, an expert in the field of Open Science, and organization and management of a scientific library. She conducts scientific research in data management in various scientific disciplines, metadata for research data, and data management support services - incl....
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Ireneusz Kreja dr hab. inż.
PeopleGraduated from the mathematical class at the Nicolaus Copernicus High School in Gdańsk (1974). Master of Sciences in Civil Engineering after studies at Gdansk University of Technology (GUT), Poland (1974-1979). Since 1979 became an employee of the GUT. In 1989 earned a Ph.D. degree in Civil Engineering (with grade "Summa cum Laude") from the GUT. In 2008 obtained a D. Sc. (Habilitation) degree in Civil Engineering (with grade...
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Grażyna Musiatowicz-Podbiał dr
PeopleNotka biograficzna Ph.D. Grażyna Musiatowicz-Podbiał is employed as an Assistant Professor in the Department of Informatics in Management, Faculty of Management and Economics of the Technical University of Gdańsk. A graduate of the Faculty of Mathematics and Computer Science at the Nicolaus Copernicus University in Toruń and the Faculty of Economics of the University of Gdańsk. In 2005, she obtained a doctoral degree in economics...
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Milena Marycz dr inż.
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Color-based Detection of Bleeding in Endoscopic Images
PublicationIn this paper a color descriptor designed for bleeding detection in endoscopic images is proposed. The development of the algorithm was carried out on a representative training set of 36 images of bleeding and 25 clear images. Another 38 bleeding and 26 normal images were used in the final stage as a test set. All of the considered images were extracted from separate endoscopic examinations. The experiments include color distribution...
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Relation-based Wikipedia Search System for Factoid Questions Answering
PublicationIn this paper we propose an alternative keyword search mechanism for Wikipedia, designed as a prototype solution towards factoid questions answering. The method considers relations between articles for finding the best matching article. Unlike the standard Wikipedia search engine and also Google engine, which search the articles content independently, requiring the entire query to be satisfied by a single article, the proposed...
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Efficiency comparison of selected endoscopic video analysis algorithms
PublicationIn the paper, selected image analysis algorithms were examined and compared in the task of identifying informative frames, blurry frames, colorectal cancer and healthy tissue on endoscopic videos. In order to standardize the tests, the algorithms were modified by removing from them parts responsible for the classification, and replacing them with Support Vector Machines and Artificial Neural Networks. The tests were performed in...
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Accelerating Video Frames Classification With Metric Based Scene Segmentation
PublicationThis paper addresses the problem of the efficient classification of images in a video stream in cases, where all of the video has to be labeled. Realizing the similarity of consecutive frames, we introduce a set of simple metrics to measure that similarity. To use these observations for decreasing the number of necessary classifications, we propose a scene segmentation algorithm. Performed experiments have evaluated the acquired...
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Endoscopy video analysis algorithms and their independence of rotation , brightness , contrast , color and blur
PublicationThe article presents selected image analysis algorithms for endoscopy videos. Mathematical methods that are part of these algorithms are described, and authors’ claims about the characteristics of these algorithms, such as the independence of rotation, brightness, contrast, etc. are mentioned. Using the common test on the real endoscopic image database and a set of image transformations, the validity of these claims was checked...
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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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Towards Facts Extraction From Texts in Polish Language
PublicationThe Polish language differs from English in many ways. It has more complicated conjugation and declination. Because of that automatic facts extraction from texts is difficult. In this paper we present basic differences between those languages. The paper presents an algorithm for extraction of facts from articles from Polish Wikipedia. The algorithm is based on 7 proposed facts schemes that are searched for in the analyzed text....
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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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Using Convolutional Neural Networks for Corneal Arcus Detection Towards Familial Hypercholesterolemia Screening
PublicationFamilial hypercholesterolemia (FH) is a highly undiagnosed disease. Among FH patients, the onset of premature coronary artery disease is 13 times higher than in the general population. Early diagnosis and treatment is essential to prevent cardiovascular diseases and their complications, and to prolong life. One of the clinical criteria of FH is the occurrence of a corneal arcus (CA) among patients, especially those under 45 years...
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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...
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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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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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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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Expedited simulation-driven design optimization of UWB antennas by means of response features
PublicationIn this work, a method for fast design optimization of broadband antennas is considered. The approach is based on a feature-based optimization (FBO) concept where reflection characteristics of the structure at hand are formulated in terms of suitably defined feature points. Redefinition of the design problem allows for reducing the design optimization cost, because the dependence of feature point coordinates on antenna dimensions...