Search results for: process modeling
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Rigid finite elements and multibody modeling in analyses of a robot shaped elastic/plastic deformations of a beam
PublicationDynamics analysis of a system composed of a parallel manipulator and of an elastic beam is presented in the paper. Classic 3RRR parallel manipulator is considered and used to deform the beam. Elasto-plastic deformations are investigated. Rigid-finite-elements technique is employed to deal with dynamics of the beam. A multibody structure is associated with the introduced hybrid system in order to model its dynamics. Idea of the...
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Improvements and new functionalities of UNRES server for coarse-grained modeling of protein structure, dynamics, and interactions
PublicationIn this paper we report the improvements and extensions of the UNRES server (https://unres-server.chem.ug.edu.pl) for physics-based simulations with the coarse-grained UNRES model of polypeptide chains. The improvements include the replacement of the old code with the recently optimized one and adding the recent scale-consistent variant of the UNRES force field, which performs better in the modeling of proteins with the β and the...
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Modeling of shear localization during confined granular flow in silos within non-local hypoplasticity.
PublicationW artykule przedstawiono wyniki numerycznej analizy lokalizacji odkształceń w materiałach granulowanych podczas przepływu w silosach. Obliczenia wykonano przy zastosowaniu metody elementów skończonych i mikropolarnego modelu hipoplastycznego. Zastosowano podejście ALE. Pokazano wpływ szorstkości ścian silosu i zagęszczenia materiału sypkiego na typ lokalizacji.
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Modeling of a cyclic plane strain compression-extension test in granular bodies within a polar hypoplasticity
PublicationW artykule przedstawiono wyniki numerycznej analizy wpływu cyklicznego ściskania-rozciągania na lokalizację odkształceń stycznych w materiałach granulowanych. Obliczenia wykonano stosując metodę elementów skończonych i mikropolarne hipoplastyczne prawo konstytutywne. Analizę przeprowadzono dla piasku zagęszczonego i luźnego dla różnych amplitud obciążenia.
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Markov Model of Disease Development and Recovery
PublicationMarkov models are commonly used to simulate diseases and allow modeling of multiple health states and outcomes. Starting with the well known Le Bras multistate model (cascading failure model) with time-independent transitions we will see how simple Markov mortality models may be pressed into the service of survival and event history analysis. We will focus on more complex models which will be able to take into account remission,...
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Seismic probabilistic assessment of steel and reinforced concrete structures including earthquake-induced pounding
PublicationRecent earthquakes demonstrate that prioritizing the retrofitting of buildings should be of the utmost importance for enhancing the seismic resilience and structural integrity of urban structures. To have a realistic results of the pounding effects in modeling process of retrofitting buildings, the present research provides seismic Probability Factors (PFs), which can be used for estimating collision effects without engaging in...
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Low-Cost Modeling of Microwave Components by Means of Two-Stage Inverse/Forward Surrogates and Domain Confinement
PublicationFull-wave electromagnetic (EM) analysis is one of the most important tools in the design of modern microwave components and systems. EM simulation permits reliable evaluation of circuits at the presence of cross-coupling effects or substrate anisotropy, as well as for accounting for interactions with the immediate environment. However, repetitive analyses required by EM-driven procedures, such as parametric optimization or statistical...
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<title>TESLA cavity modeling and digital implementation with FPGA technology solution for control system development</title>
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Usability of accident and incident reports for evidence-based risk modeling – A case study on ship grounding reports
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Structure–activity relationships study on biological activity of peptides as dipeptidyl peptidase IV inhibitors by chemometric modeling
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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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Modeling of the fascia-mesh system and sensitivity analysis of a junction force after a laparoscopic ventral hernia repair
PublicationW pracy rozpatrywano prosty model cięgnowy układu powięż-siatka do oszacowania siły połączenia siatki z powięzią po operacji laparoskopowej przepukliny brzusznej. Cięgno obciążone jest ciśnieniem wewnątrz brzusznym, symulującym kaszel, oraz przemieszczeniami jego końców wywołanymi skłonami pacjenta. Wpływ poszczególnych parametrów cięgna na siłę połączenia określono za pomocą analizy wrażliwości. Sformułowano pewne wnioski ważne...
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Modeling of wind wave induced sediment transport in the coastal zone of polish marine areas (Southern Baltic)
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The comparison of semiempirical and ab initio molecular modeling methods in activity and property evaluation of selected antimicrobial sulfonamides
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Fuzzy soft modeling of environmental data. A study of the impact of a Phosphatic Fertilizer Plant on the adjacent environment in Gdańsk
PublicationAnaliza podobieństwa obejmuje nie tylko zastosowanie logiki rozmytej, ale również wiele innych podejść matematycznych. Opracowano wiele algorytmów, których celem jest wyodrębnienie wyraźnych skupień (hard clusters) z danego zbioru danych. Prawdopodobnie najczęściej stosowanymi algorytmami są tzw. algorytmy c-średnie (c-means algorithms). Twarde c-średnie (hard c-means) służy do ostrej klasyfikacji, podczas której obiekt jest przypisany...
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Modeling of the M X-ray line structures for tungsten and L X-ray line structures for molybdenum
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An Example of Using Low-Cost LiDAR Technology for 3D Modeling and Assessment of Degradation of Heritage Structures and Buildings
PublicationThis article examines the potential of low-cost LiDAR technology for 3D modeling and assessment of the degradation of historic buildings, using a section of the Koszalin city walls in Poland as a case study. Traditional terrestrial laser scanning (TLS) offers high accuracy but is expensive. The study assessed whether more accessible LiDAR options, such as those integrated with mobile devices such as the Apple iPad Pro, can serve...
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Improved Efficacy Behavioral Modeling of Microwave Circuits through Dimensionality Reduction and Fast Global Sensitivity Analysis
PublicationBehavioral models have garnered significant interest in the realm of high-frequency electronics. Their primary function is to substitute costly computational tools, notably electromagnetic (EM) analysis, for repetitive evaluations of the structure under consideration. These evaluations are often necessary for tasks like parameter tuning, statistical analysis, or multi-criterial design. However, constructing reliable surrogate models...
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Modeling and optimization of chemical-treated torrefaction of wheat straw to improve energy density by response surface methodology
PublicationToday, torrefaction is important technique for extending the potential of biomass for improvement of energy density. The independent variables investigated for torrefaction study were temperature, retention time, acid concentration, and particle size. The experiment was designed by central composite design (CCD) method using design expert (version 11). The three dependent variables were higher heating value (HHV), energy enhancement...
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A LUMPED-CIRCUIT MODEL OF CIRCULAR PISTON TRANSDUCER FOR MODELING ITS PERFORMANCE IN DUAL FREQUENCY OPERATING MODES
PublicationThe paper presents novel network equivalent circuit of piezoceramic circular disc transducer that takes into account thickness and ra dial mode of vibrations. The starting point of the analysis is 4-port description of circular disc element representing the solution of wave equation set in radial and thickness directions. Th e approximate solution for harmonic case is represented in the form of 4x4 matrix, which is syn thesized...
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Experimental Comparison of Straight Lines and Polynomial Interpolation Modeling Methods in Ship Evolutionary Trajectory Planning Problem
PublicationPaper presents the application of evolutionary algorithms and polynomial interpolation in ship evolutionary trajectory planning method and its comparison to classic approach, where trajectory is modeled by straight lines. Evolutionary algorithms are group of methods that allows\ to find a collision free trajectory in real time, while polynomial interpolation allows to model smooth trajectory, which keeps continuity of velocity...
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How the “Liquid Drop” Approach Could Be Efficiently Applied for Quantitative Structure–Property Relationship Modeling of Nanofluids
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Modeling, simulation, and validation of a TB41 crash test of the H2/W5/B concrete vehicle restraint system
PublicationThe paper addresses numerical simulations of a concrete vehicle restraint system. The model is described in detail. The advanced material law of the continuous surface cap model was used to analyze the damage locations in concrete barrier segments. The results were validated against the TB41 full-scale crash test. The test was conducted in compliance with European standard EN 1317, and the validation was performed in accordance...
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Modeling of a Quasi-Resonant DC Link Inverter Dedicated to Common-Mode Voltage and Ground Current Reduction
PublicationIn this paper, the modeling methodology of the AC drive system with a Parallel Quasi-Resonant DC Link Inverter (PQRDCLI) is described. A presented modeling approach is an attractive tool used for the effective evaluation of a common-mode (CM) voltage and grounds current reduction methods. Designed models of inverter, induction machine (IM), and cable are simple, thus the methods for parameter extraction are not complicated. Verification...
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Two- and three-dimensional elastic networks with rigid junctions: modeling within the theory of micropolar shells and solids
PublicationFor two- and three-dimensional elastic structures made of families of flexible elastic fibers undergoing finite deformations, we propose homogenized models within the micropolar elasticity. Here we restrict ourselves to networks with rigid connections between fibers. In other words, we assume that the fibers keep their orthogonality during deformation. Starting from a fiber as the basic structured element modeled by the Cosserat...
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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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Cost-Efficient Two-Level Modeling of Microwave Passives Using Feature-Based Surrogates and Domain Confinement
PublicationA variety of surrogate modelling techniques has been utilized in high-frequency design over the last two decades. Yet, the curse of dimensionality still poses a serious challenge in setting up re-liable design-ready surrogates of modern microwave components. The difficulty of the model-ing task is only aggravated by nonlinearity of circuit responses. Consequently, constructing a practically usable surrogate model, valid across...
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Reliable computationally-efficient behavioral modeling of microwave passives using deep learning surrogates in confined domains
PublicationThe importance of surrogate modeling techniques has been steadily growing over the recent years in high-frequency electronics, including microwave engineering. Fast metamodels are employed to speedup design processes, especially those conducted at the level of full-wave electromagnetic (EM) simulations. The surrogates enable massive system evaluations at nearly EM accuracy and negligible costs, which is invaluable in parameter...
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Release of Encapsulated Bioactive Compounds from Active Packaging/Coating Materials and Its Modeling: A Systematic Review
PublicationThe issue of achieving controlled or targeted release of bioactive compounds with specific functional properties is a complex task that requires addressing several factors, including the type of bioactive, the nature of the delivery system, and the environmental conditions during transportation and storage. This paper deals with extensive reporting for the identification of original articles using Scopus and Google Scholar based...
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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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Polyurethanes as a Potential Medical-Grade Filament for Use in Fused Deposition Modeling 3D Printers – a Brief Review
PublicationThe possibility of using 3D printing technology (3DP) in medical field is a kind of revolution in health care. This has contributed to a rapid growth in demand for 3D printers, whose systems and materials are adapted to strict medical requirements. In this paper, we report a brief review of polyurethanes as a potential medical-grade filament for use in Fused Deposition Modeling (FDM) 3D printer technology. The advantages of polyurethanes...
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Modeling the impact of rotor movement on non-linearity of motor currents waveforms in high-speed PMSM drives
PublicationMotor current measurement techniques as well as predictive control algorithms for electric drives rely on an assumption of linear motor currents changes resulting from constant inverter output voltages. Recent research has reported that this assumption does not hold in motors with short electrical time constant, and in drives whose rotor position advances substantially during a control period. This paper proposes a simulation model...
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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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FE-modeling of shear resistance degradation in granular materials during cyclic shearing under CNS condition
PublicationW artykule przedstawiono wyniki numerycznej analizy degradacji wytrzymałości na ścinanie w materiałach granulowanych podczas cyklicznego ścinania z warunkiem stałej sztywności normalnej. Obliczenia wykonano przy zastosowaniu metody elementów skończonych i mikropolarnego modelu hipoplastycznego.
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Evaluation of open drone map toolkit for geodetic grade aerial drone mapping – case study
PublicationAn open source tool’s popularity has increased considerably, as well as micro aerial vehicles (MAV) technologies based on open source hardware. An open source software and hardware delivers a wide variety of applications and technology. The world’s most successful open source projects have their roots in the academy, and now its participation includes a wide variety of academic programs and research. Based on open source technology,...
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Static and Dynamic Mechanical Properties of 3D Printed ABS as a Function of Raster Angle
PublicationDue to the rapid growth of 3D printing popularity, including fused deposition modeling (FDM), as one of the most common technologies, the proper understanding of the process and influence of its parameters on resulting products is crucial for its development. One of the most crucial parameters of FDM printing is the raster angle and mutual arrangement of the following filament layers. Presented research work aims to evaluate different...
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A continual model of a damaged medium used for analyzing fatigue life of polycrystalline structural alloys under thermal–mechanical loading
PublicationThe main physical laws of thermal–plastic deformation and fatigue damage accumulation processes in polycrystalline structural alloys under various regimes of cyclic thermal–mechanical loading are considered. Within the framework of mechanics of damaged media, a mathematical model is developed that describes thermal–plastic deformation and fatigue damage accumulation processes under low-cycle loading. The model consists of three...
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Structures for parameterization, meshing and data exchange of topologically related surfaces of a ship hull
PublicationThis paper presents proposal of data structures for storage and processing of a parametric three-dimensional model of a midship hull sections. The model consists of coarse surfaces like: decks, frames, girders, stiffeners, brackets, partitions etc. bounded by topological relations. All workshop details are omitted as the model is intended for numeric calculations. Proposed data structures are prepared to facilitate changes in the...
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Model of a Maturity Capsule in Managing IT Projects
PublicationThe main purpose of this article is to present a report on the development of a model of information technology management (MITM). This model is an answer to the need to support decision making in the selection of methods and information technologies. This article presents a multisequential model (MSM) of technology selection and a model for initial processing procedures (IPP) necessary for the MITM model. The presentation of the...
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Efficient Multi-Objective Simulation-Driven Antenna Design Using Co-Kriging
PublicationA methodology for fast multi-objective antenna optimization is presented. Our approach is based on response surface approximation (RSA) modeling and variable-fidelity electromagnetic (EM) simulations. In the design process, a computationally cheap RSA surrogate model constructed from sampled coarse-discretization EM antenna simulations is optimized using a multi-objective evolutionary algorithm. The initially determined Pareto...
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Searching for Solvents with an Increased Carbon Dioxide Solubility Using Multivariate Statistics
PublicationIonic liquids (ILs) are used in various fields of chemistry. One of them is CO2 capture, a process that is quite well described. The solubility of CO2 in ILs can be used as a model to investigate gas absorption processes. The aim is to find the relationships between the solubility of CO2 and other variables—physicochemical properties and parameters related to greenness. In this study, 12 variables are used to describe a dataset...
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Concept of Multifactor Method and Non-Functional Requirements Solution to Increase Resilience through Functional Safety with Cybersecurity Analysis
PublicationIn the process of designing safety systems, an integrated approach in safety and cybersecurity analysis is necessary. The paper describes a new technique of increasing resilience through integrated analysis of functional safety and cybersecurity. It is a modeling methodology based on the combination of the multifactor method utilizing modified risk graphs, used previously for Safety Integrity Level (SIL) assessment, and the Non-Functional...
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Corporate social responsibility practices incomes and outcomes: Stakeholders' pressure, culture, employee commitment, corporate reputation, and brand performance. A Polish–German cross‐country study
PublicationThis study aims to compare employee perception of corporate social responsibility (CSR) practice incomes and outcomes in the construction industry in Poland and Germany. It proposes a model that examines the influence of stakeholder pressure, culture, and CSR practices on company brand performance, reputation, and employee identification. The findings suggest that the structure of relationships varies for project‐managed construction...
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Revisiting The Determination Of Cutting Power While Sawing Of Wood With Circular Saw Blades By Means Of Fracture Mechanics
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specific cutting resistance, which is in the case of wood cutting the function of more or less important factors. On the other hand, cutting forces (power) could be considered from a point of view of modern fracture mechanics. Cutting forces may be employed to determine not only toughness...
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Mathematical modelling and computer simulation of activated sludge systems.Second edition
PublicationMathematical Modelling and Computer Simulation of Activated Sludge Systems – Second Edition, provides, from the process engineering perspective, a comprehensive and up-to-date overview regarding various aspects of the mechanistic (“white box”) modelling and simulation of advanced activated sludge systems performing biological nutrient removal. In the new edition of the book, a special focus is given to nitrogen removal and an overview...
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Estimation of groundwater recharge in a shallow sandy aquifer using unsaturated zone modeling and water table fluctuation method
PublicationQuantification of groundwater recharge is one of the most important issues in hydrogeology, especially in view of the ongoing changes in climate and land use. In this study, we use numerical models of 1D vertical flow in the vadose zone and the water table fluctuation (WTF) analysis to investigate local-scale recharge of a shallow sandy aquifer in the Brda outwash plain in northern Poland. We show that these two methods can be...
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Some Aspects of Shear Behavior of Soft Soil–Concrete Interfaces and Its Consequences in Pile Shaft Friction Modeling
PublicationThis paper examines the stiffness degradation and interface failure load on soft soil–concrete interface. The friction behavior and its variability is investigated. The direct shear tests under constant normal load were used to establish parameters to hyperbolic interface model which provided a good approximation of the data from instrumented piles. Four instrumented piles were used to obtain reference soil–concrete interface behavior....
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Use of structural equation modeling in quantitative research in the field of management and economics: A bibliometric analysis in the systematic literature review
PublicationPURPOSE: This paper aims to provide a comprehensive review of scholarly research focusing on using quantitative methods and particularly structural equation modeling (SEM) in management and economics studies, as well as provide a bibliometric agenda including the time horizon of individual publications, the highest citation rate, geographic and industry areas, methodological context, and keywords. METHODOLOGY: A systematic literature...
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Expedited Acquisition of Database Designs for Reduced-Cost Performance-Driven Modeling and Rapid Dimension Scaling of Antenna Structures
PublicationFast replacement models have been playing an increasing role in high-frequency electronics, including the design of antenna structures. Their role is to improve computational efficiency of the procedures that normally entail large numbers of expensive full-wave electromagnetic (EM) simulations, e.g., parametric optimization or uncertainty quantification. Recently introduced performance-driven modeling methods, such as the nested...
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Quantum chemical modeling (DFT) of active species on the VWO catalyst surface in various redox conditions
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