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Nonlinear Modeling in Time Domain Numerical Analysis of Stringed Instrument Dynamics
PublikacjaMusical instruments are very various in terms of sound quality with their timbre shaped by materials and geometry. Materials' impact is commonly treated as dominant one by musicians, while it is unclear whether it is true or not. The research proposed in the study focuses on determining influence of both these factors on sound quality based on their impact on harmonic composition. Numerical approach has been chosen to allowed independent...
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Design-Oriented Two-Stage Surrogate Modeling of Miniaturized Microstrip Circuits with Dimensionality Reduction
PublikacjaContemporary microwave design heavily relies on full-wave electromagnetic (EM) simulation tools. This is especially the case for miniaturized devices where EM cross-coupling effects cannot be adequately accounted for using equivalent network models. Unfortunately, EM analysis incurs considerable computational expenses, which becomes a bottleneck whenever multiple evaluations are required. Common simulation-based design tasks include...
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On Inadequacy of Sequential Design of Experiments for Performance-Driven Surrogate Modeling of Antenna Input Characteristics
PublikacjaDesign of contemporary antennas necessarily involves electromagnetic (EM) simulation tools. Their employment is imperative to ensure evaluation reliability but also to carry out the design process itself, especially, the adjustment of antenna dimensions. For the latter, traditionally used parameter sweeping is more and more often replaced by rigorous numerical optimization, which entails considerable computational expenses, sometimes...
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Improved Modeling of Microwave Structures Using Performance-Driven Fully-Connected Regression Surrogate
PublikacjaFast replacement models (or surrogates) have been widely applied in the recent years to accelerate simulation-driven design procedures in microwave engineering. The fundamental reason is a considerable—and often prohibitive—CPU cost of massive full-wave electromagnetic (EM) analyses related to solving common tasks such as parametric optimization or uncertainty quantification. The most popular class of surrogates are data-driven...
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Dynamic Modeling of COVID-19 Disease with Impact of Lockdown in Pakistan and Malaysia
PublikacjaBeing researchers, it is an utmost responsibility to provide insight on social issues thus, this work addresses the dynamic modeling of first and most contagious disease named as COVID-19 caused by coronavirus. The first case of COVID-19 appeared in Pakistan was on 26th February 2020 and in Malaysia on 27th February 2020; both patients had foreign travel history. In the paper, the number of total affected cases and total deaths...
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Chosen aspects of skeletal system modeling: Numerical solid and shell models of femur part
PublikacjaThe purpose of this paper is to present a new method of femur part modeling by using the finite element method. This method treats a femur part as a system composed of cortical and trabecular bone. For the purpose of determining a proper shape of femur part model there were created three models: a) the first one describes a femur part as a solid structure; b) the second one describes a femur part as a connection of cortical bone...
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Modeling lignin extraction with ionic liquids using machine learning approach
PublikacjaLignin, next to cellulose, is the second most common natural biopolymer on Earth, containing a third of the organic carbon in the biosphere. For many years, lignin was perceived as waste when obtaining cellulose and hemicellulose and used as a biofuel for the production of bioenergy. However, recently, lignin has been considered a renewable raw material for the production of chemicals and materials to replace petrochemical resources....
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Achieving Efficient and Stable Deammonification at Low Temperatures—Experimental and Modeling Studies
PublikacjaThe short-term effects of temperature on deammonification sludge were evaluated in a laboratory-scale sequencing batch reactor (SBR). Mathematical modeling was used for further evaluations of different intermittent aeration strategies for achieving high and stable deammonification performance at decreasing temperatures. As for the biomass cultivated at high temperatures (e.g., 30 C), a higher temperature dependency (the adjusted...
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THE CONCEPT OF MODELING OF SNOW IMPACT ON THE STRUCTURE OF THE SUSPENDED TAURON ARENA ROOF IN CRACOW
PublikacjaThe article presents studies and numerical simulations on modeling snow influence on TAURON ARENA suspended roof structure in Cracow. The scope of work includes experimental tests, functions solutions taking into account various cases of snow impact according to PN and EC, as well as numerical simulations for the sport and entertainment arena in the Czyzyny district. The FEM roof structure model developed in the SOFISITK software...
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Weather Hazard Avoidance in Modeling Safety of Motor-Driven Ship for Multicriteria Weather Routing
PublikacjaWeather routing methods find the most suitable ocean?s route for a vessel, taking into account changeable weather conditions and navigational constraints. In the multicriteria approach based on the evolutionary SPEA algorithm one is able to consider a few constrained criteria simultaneously. The approach applied for a ship with hybrid propulsions has already been presented by one of the authors on previous TransNav?2009. This time...
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Modeling of Surface Roughness in Honing Processes by UsingFuzzy Artificial Neural Networks
PublikacjaHoning processes are abrasive machining processes which are commonly employed to improve the surface of manufactured parts such as hydraulic or combustion engine cylinders. These processes can be employed to obtain a cross-hatched pattern on the internal surfaces of cylinders. In this present study, fuzzy artificial neural networks are employed for modeling surface roughness parameters obtained in finishing honing operations. As...
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Rapid Design of 3D Reflectarray Antennas by Inverse Surrogate Modeling and Regularization
PublikacjaReflectarrays (RAs) exhibit important advantages over conventional antenna arrays, especially in terms of realizing pencil-beam patterns without the employment of the feeding networks. Unfortunately, microstrip RA implementations feature narrow bandwidths, and are severely affected by losses. A considerably improved performance can be achieved for RAs involving grounded dielectric layers, which are also easy to manufacture using...
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Modeling N2O behavior during denitrification with different carbon sources and electron acceptors
PublikacjaA mathematical model was developed for identification of the most important mechanism leading to nitrous oxide (N2O) accumulation in denitrifying activated sludge systems. The activated sludge model No. 2d (ASM2d) was extended to include intermediate three steps of the denitrification process. The formation and accumulation of nitric oxide (NO) was assumed to be very low in the performed laboratory experiments. These experiments...
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Modeling by finite element methods of impact of erosion on frequency of normal modes of L-0 blade
PublikacjaAfter some time of exploitation steam turbine rotors blades in energetic industry they are being eroded and also their frequency of normal modes is changed. Those changes can cause to unwanted shift of blades normal mode frequencies. It is necessary to find quick method of rating changes of frequency in connection of mass loss due erosion. The evaluation of this dependence was made by finite element modeling method using HyperWorks...
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Surrogate modeling of impedance matching transformers by means of variable‐fidelity electromagnetic simulations and nested cokriging
PublikacjaAccurate 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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Uniform sampling in constrained domains for low-cost surrogate modeling of antenna input characteristics
PublikacjaIn this letter, a design of experiments technique that permits uniform sampling in constrained domains is proposed. The discussed method is applied to generate training data for construction of fast replacement models (surrogates) of antenna input characteristics. The modeling process is design-oriented with the surrogate domain spanned by a set of reference designs optimized with respect to the performance figures and/or operating...
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Modeling Methodologies for the Environment EE Msc sem. II r.a. 23/24
Kursy OnlineZrozumienie procesów które mają wpływ na migrację i przemiany zanieczyszczeń w środowisku (ze szczególnym uwzględnieniem wód powierzchniowych). Zajęcia dotyczą podstaw i zasad budowy modeli jakości wody oraz służą pokazaniu jak te modele mogą być wykorzystywane do rozwiązywania problemów w inżynierii środowiska.
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Computational Analysis of Transformational Organisational Change with Focus on Organisational Culture and Organisational Learning: An Adaptive Dynamical Systems Modeling Approach
PublikacjaTransformative Organisational Change becomes more and more significant both practically and academically, especially in the context of organisational culture and learning. However computational modeling and formalization of organisational change and learning processes are still largely unexplored. This chapter aims to provide an adaptive network model of transformative organisational change and translate a selection of organisational...
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Journal of Advances in Modeling Earth Systems
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International Journal of Economics and Business Modeling
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Advanced Modeling and Simulation in Engineering Sciences
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Journal of Applied Structural Equation Modeling
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Multiscale and Multidisciplinary Modeling, Experiments and Design
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ACM Transactions on Modeling and Computer Simulation
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International Journal of Numerical Analysis and Modeling
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Structural Equation Modeling: A Multidisciplinary Journal
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USER MODELING AND USER-ADAPTED INTERACTION
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Expedited Acquisition of Database Designs for Reduced-Cost Performance-Driven Modeling and Rapid Dimension Scaling of Antenna Structures
PublikacjaFast 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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Modeling two phase flow in large scale fractured porous media with an extended multiple interacting continua method
PublikacjaWe present a two phase flow conceptual model, the corresponding simulator (2pMINC) and a workflow for large-scale fractured reservoirs, based on a continuum fracture approach which uses the multiple interacting continua (MINC) method complemented with an improved upscaling technique. The complex transient behavior of the flow processes in fractured porous media is captured by subgridding the coarse blocks in nested volume elements...
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The CFD modeling in bioreactor tracer studies
PublikacjaW artykule zaprezentowano badania traserowe w bioreaktorach z osadem czynnym. Przedstawiono efekty działania procesu dyspersji na podstawie obliczonych podłużnych profili koncentracji znacznika w komorach osadu czynnego zlokalizowanych na Oczyszczalni Ścieków "Wschód" w Gdańsku. W ramach badań wykonano symulację przepływu substancji nieaktywnej (bazując na pomierzonych profilach stężenia znacznika) stosując jednowymiarowe równanie...
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Computer modeling and testing of structural metamaterials
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Modeling of nonlinear generation in a bubble layer
PublikacjaPraca prezentuje numeryczne podejście do zagadnienia liniowego i nieliniowego rozpraszania w warstwie z pęcherzykami. Badania numeryczne niekoherentnego rozpraszania wykonano stosując metodę Monte Carlo. Propagację i wsteczne rozpraszanie sygnałów badano w oparciu o równanie Rayleigha-Plesseta.
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Molecular Modeling of Meta II Rhodopsin
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Modeling Dynamics of Autonomous Underwater Vehicle.
PublikacjaArtykuł dotyczy budowy modelu autonomicznego pojazdu podwodnego do celów syntezy układu sterowania pojazdem. Rozważany pojazd ma długośc ok. 1 m i 30 cm średnicy. Wyposażony jest w 5 pędników, które pozwalają na sterowanie w pięciu stopniach swobody. Do badań wykorzystano model o 4 stopniach swobody. Dokonano identyfikacji parametrycznej modelu. Model zrealizowano w środowisku programowym Matlab/Simulink.
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Systems modeling and simulation for environmental management.
PublikacjaW pracy omówiono podstawy systemowego modelowania i symulacji w szerokim zakresie zagadnień związanych z zarządzaniem przepływami informacji w środowisko naturalnym.
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On constitutive modeling for technical woven fabric
PublikacjaW pracy przestawiono kilka modeli konstytutywnych przyjmowanych do opisu zachowania się tkanin technicznych. Oprócz modeli zaczerpniętych z literatury autorzy prezentują własną koncepcje modelu stanowiąca rozszerzenie modelu sieci gęstej.This paper describes several types of the constitutive models used for the technical woven fabric description. Besides of the literatures examples of the constitutive models, the authors presented...
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A methodology of visual modeling language evaluation
PublikacjaMetody oceny jakości metod modelowania są istotnym elementem inżynierii języków modelowania wizualnego. W referacie zaproponowano metodę oceny języków modelowania wizualnego na podstawie wymiarów poznawczych. Zaprezentowano metodologiczną dyskusję zastosowania nauk psychologicznych do oceny metod modelowania, metodologię CD-VML, powiązaną z nią metodę CD-VML-UC do oceny przypadków użycia oraz weryfikację metodologii.
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Numerical modeling of quantum dynamical processes
PublikacjaIn this dissertation I present a high-precision (15, 18 or 33 decimal places) C++ implementation of quantum dynamics time propagation algorithms for both time-independent and time-dependent Hamiltonian with an inhomogeneous source term. Moreover I present an extension of both algorithms for time propagation to handle arbitrary number of coupled electronic levels. I have performed a careful validation of these implementations comparing...
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Modeling of light propagation in canine gingiva
PublikacjaThis study is a preliminary evaluation of the effectivenes of laser-based surgery of maxillary and mandibular bone in dogs. Current methods of gingivial surgery in dogs require the use of general anaesthesia.1, 2 The proposed methods of laser surgery can be performed on conscious dogs, which substantially reduces the associated risks. Two choices of lasers, Nd:YAG and a 930 nm semiconductor lasers were evaluated. The former is...
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Modeling DAC Application Execution Time
PublikacjaAn application written in the Divide And Conquer paradigm is more difficult to model than SPMD application because of complex algorithm, causing use of many coefficients in a computational complexity function. Processors are divided into various layers, each layer contains different number of processors. Data packets processed in different layers and transferred between layers have different length. Moreover first layer processors use...
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Modeling bioaugmentation with nitrifiers in membrane bioreactors
PublikacjaBioaugmentation with nitrifiers was studied using two pilot-scale membrane bioreactors, with the purpose of assessing the suitability of state-of-the-art activated sludge models (ASMs) in predicting the efficiency of bioaugmentation as a function of operating conditions. It was demonstrated that the temperature difference between seeding and seeded reactors (ΔT) affects bioaugmentation efficiency. Experimental data were accurately...
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Application of muscle model to the musculoskeletal modeling
PublikacjaThe purpose of this paper is to investigate new fusiform muscle models. Each of these models treats a muscle as a system composedof parts characterized by different mechanical properties. These models explain the influence of differences in the stiffness of lateral parts and the degree of muscle model discretization. Each muscle model is described by a system of differential equations and a single integro-differential equation....
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Alternative Modeling of Volunteer Based Systems
PublikacjaThe canonical approach to model a flow of a voluntary based computing, as presented in Chapter 7 may tax the capacity of the simulator, especially when a more complex model of Voluntary Computing, proposed in [1], is used which would imply that, for typical heterogeneous groups of volunteers, several thousands of threads would have to be run inside the simulator, to mimic closely the behaviour of every volunteer. This chapter presents...
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Low-Cost and Highly-Accurate Behavioral Modeling of Antenna Structures by Means of Knowledge-Based Domain-Constrained Deep Learning Surrogates
PublikacjaThe awareness and practical benefits of behavioral modeling methods have been steadily growing in the antenna engineering community over the last decade or so. Undoubtedly, the most important advantage thereof is a possibility of a dramatic reduction of computational expenses associated with computer-aided design procedures, especially those relying on full-wave electromagnetic (EM) simulations. In particular, the employment of...
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Accelerated multi-objective design optimization of antennas by surrogate modeling and domain segmentation
PublikacjaMulti-objective optimization yields indispensable information about the best possible design trade-offs of an antenna structure, yet it is challenging if full-wave electromagnetic (EM) analysis is utilized for performance evaluation. The latter is a necessity for majority of contemporary antennas as it is the only way of achieving acceptable modeling accuracy. In this paper, a procedure for accelerated multi-objective design of...
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Modeling and Strength Calculations of Parts Made Using 3D Printing Technology and Mounted in a Custom-Made Lower Limb Exoskeleton
PublikacjaThis study is focused on the application of 3D-printed elements and conventional elements to create a prototype of a custom-made exoskeleton for lower limb rehabilitation. The 3D-printed elements were produced by using Fused Deposition Modeling technology and acrylonitrile butadiene styrene (ABS) material. The scope of this work involved the design and construction of an exoskeleton, experimental testing of the ABS material and...
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Reliable data-driven modeling of high-frequency structures by means of nested kriging with enhanced design of experiments
PublikacjaData-driven (or approximation) surrogate models have been gaining popularity in many areas of engineering and science, including high-frequency electronics. They are attractive as a way of alleviating the difficulties pertinent to high computational cost of evaluating full-wave electromagnetic (EM) simulation models of microwave, antenna, and integrated photonic components and devices. Carrying out design tasks that involve massive...
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Results of modeling of pharmaceuticals mixtures toxicity with deviation ratio and best-fit functions models using Aliivibrio fischeri bacterium as model organism
Dane BadawczeThe research was concerned with verifying the impact of mixtures of nine pharmaceuticals against a selected organism, i.e., the bacterium Aliivibrio fischeri. A. fisheri is used as a model organism in the monitoring of acute toxicity in environmental and reference samples in Microtox® systems. Tested pharmaceuticals, namely: diclofenac (sodium salt),...
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Numerical modeling and experimental validation of full-scale segment to support design of novel GFRP footbridge
PublikacjaThe paper contains analysis of full-scaled three meters long segment of a novel composite footbridge. Both numerical modeling and experimental validation were performed. Analyzed object is a shell type sandwich channel-like structure made of composite sandwich with GFRP laminates as a skin and PET foam as a core. Several static load schemes were performed including vertical and horizontal forces. In FEM analysis multilayered laminate...
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Indirect adaptive controller based on a self-structuring fuzzy system for nonlinear modeling and control
PublikacjaIn this paper, a unified nonlinear modeling and control scheme is presented. A self-structuring Takagi-Sugeno (T-S) fuzzymodel is used to approximate the unknown nonlinear plant based on I/O data collected on-line. Both the structure and theparameters of the T-S fuzzy model are updated by an on-line clustering method and a recursive least squares estimation(RLSE) algorithm. The rules of the fuzzy model can be added, replaced or...