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Search results for: 4D modelling
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POM/EVA Blends with Future Utility in Fused Deposition Modeling
PublicationPolyoxymethylene (POM) is one of the most popular thermoplastic polymers used in the industry. Therefore, the interest in its potential applications in rapid prototyping is understandable. Nevertheless, its low dimensional stability causes the warping of 3D prints, limiting its applications. This research aimed to evaluate the effects of POM modification with ethylene-vinyl acetate (EVA) (2.5, 5.0, and 7.5 wt.%) on its processing...
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Mispronunciation Detection in Non-Native (L2) English with Uncertainty Modeling
PublicationA common approach to the automatic detection of mispronunciation in language learning is to recognize the phonemes produced by a student and compare it to the expected pronunciation of a native speaker. This approach makes two simplifying assumptions: a) phonemes can be recognized from speech with high accuracy, b) there is a single correct way for a sentence to be pronounced. These assumptions do not always hold, which can result...
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Two-Stage Variable-Fidelity Modeling of Antennas with Domain Confinement
PublicationSurrogate modeling has become the method of choice in solving an increasing number of antenna design tasks, especially those involving expensive full-wave electromagnetic (EM) simulations. Notwithstanding, the curse of dimensionality considerably affects conventional metamodeling methods, and their capability to efficiently handle nonlinear antenna characteristics over broad ranges of the system parameters is limited. Performance-driven...
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Systems, Environments, and Soliton Rate Equations: Toward Realistic Modeling
PublicationIn order to solve a system of nonlinear rate equations one can try to use some soliton methods. The procedure involves three steps: (1) find a ‘Lax representation’ where all the kinetic variables are combined into a single matrix ρ, all the kinetic constants are encoded in a matrix H; (2) find a Darboux–Bäcklund dressing transformation for the Lax representation iρ˙=[H,f(ρ)], where f models a time-dependent environment; (3) find...
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Electromagnetic Modeling of Microstrip Elements Aided with Artificial Neural Network
PublicationThe electromagnetic modeling principle aided withartificial neural network to designing the microwave widebandelements/networks prepared in microstrip technology is proposedin the paper. It is assumed that the complete information is knownfor the prototype design which is prepared on certain substratewith certain thickness and electric permittivity. The longitudinaland transversal dimensions of new design...
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Performance and Power-Aware Modeling of MPI Applications for Cluster Computing
PublicationThe paper presents modeling of performance and power consumption when running parallel applications on modern cluster-based systems. The model includes basic so-called blocks representing either computations or communication. The latter includes both point-to-point and collective communication. Real measurements were performed using MPI applications and routines run on three different clusters with both Infiniband and Gigabit Ethernet...
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Thermodynamic modeling of combustion process of the internal combustion engines – an overview
PublicationThe mathematical description of combustion process in the internal combustion engines is a very difficult task, due to the variety of phenomena that occurring in the engine from the moment when the fuel-air mixture ignites up to the moment when intake and exhaust valves beginning open. Modeling of the combustion process plays an important role in the engine simulation, which allows to predict incylinder pressure during the combustion,...
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Open Data Capability Architecture - An Interpretive Structural Modeling Approach
PublicationDespite of increasing availability of open data as a vital organizational resource, large numbers of startups and organizations fail when it comes to utilizing open data effectively. This shortcoming is attributable to the poor understanding of what types of capabilities are required to successfully conduct data related activities. At the same time, research on open data capabilities and how they relate to one another remains sparse....
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Performance-Based Nested Surrogate Modeling of Antenna Input Characteristics
PublicationUtilization of electromagnetic (EM) simulation tools is mandatory in the design of contemporary antenna structures. At the same time, conducting designs procedures that require multiple evaluations of the antenna at hand, such as parametric optimization or yield-driven design, is hindered by a high cost of accurate EM analysis. To certain extent, this issue can be addressed by utilization of fast replacement models (also referred...
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Comparative analysis of various transformation techniques for voiceless consonants modeling
PublicationIn this paper, a comparison of various transformation techniques, namely Discrete Fourier Transform (DFT), Discrete Cosine Transform (DCT) and Discrete Walsh Hadamard Transform (DWHT) are performed in the context of their application to voiceless consonant modeling. Speech features based on these transformation techniques are extracted. These features are mean and derivative values of cepstrum coefficients, derived from each transformation....
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Modeling 3D Objects for Navigation Purposes Using Laser Scanning
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CFD modeling of a diesel evaporator used in fuel cell systems
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ACID whey concentrated by ultrafiltration a tool for modeling bread properties
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Proposal of BPMN extension with a view to effective modeling of clinical pathways
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New approach to railway noise modeling employing Genetic Algorithms
PublicationMain goal of this paper was to describe an innovative method of noise prediction based on Genetic Algorithms. First part of the paper addresses the problem of growing noise, mainly in the context of a unified method for measuring noise. Further, Genetic Algorithms are described with regards to their fundamental features. Further a description is provided as to how Genetic Algorithms were used in the area of noise modeling. Next...
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Modeling of active fiber Bragg grating underwater acoustic sensor.
PublicationW pracy przedstawiono wyniki modelowania nowego typu przetwornika hydroakustycznego wykorzystującego światłowodową siatkę Bragga. Siatka ta, domieszkowana jonami pierwiastków ziem rzadkich, pracuje jako laser z rozłożonym sprzężeniem zwrotnym, co pozwala na znaczne zwiększenie czułości tego prztwornika w porównaniu z rozwiązaniami wykorzystującymi siatki pasywne. W celu uzyskania równomiernego rozkładu naprężeń siatki zastosowano...
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Comprehensive modeling of interferometric hydrophone with self-supported mandrel transducer.
PublicationW pracy przedstawiono wyniki modelowania nowego typu samonośnego przetwornika dla interferometrycznego hydrofonu światłowodowego. Zaprezentowano wyniki analizy statycznej, modowej i dynamicznej przeprowadzonej przy pomocy Metody Elementów Skończonych. W modelowaniu wykorzyastano techniki opracowane dla laminatów, co pozwoliło na uzyskanie dokładnych wyników przy względnie krótkim czasie obliczeń.
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Application of virtual reality modeling language for 3D seafloor imaging.
PublicationW artykule przedstawiono koncepcję wykorzystania języka opisu wirtualnej rzeczywistości do trójwymiarowej wizualizacji objektów znajdujących się na dnie morskim w zastosowaniu do danych pochodzących z systemów hydroakustycznych. W szczególności zaprezentowano technikę tworzenia trójwymiarowych scen przeznaczonych do szerokiego udostępniania w sieci Internet.
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Submerged object imaging using virtual reality modeling language.
PublicationArtykuł przedstawia sposób wykorzystania języka opisu wirtualnej rzeczywistości w archeologii podwodnej. Przedstawiono propozycję wizualizacji objektów znajdujących się na dnie morskim, a w szczególności zaprezentowano technikę rekonstrukcji obrazu trójwymiarowego z danych pochodzących z sonaru wielowiązkowego.
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Some aspects of physical and numerical modeling of water hammer in pipelines
PublicationCharakterystyki ciśnieniowe otrzymywane w wyniku symulacji numerycznych uderzenia hydraulicznego różnią się zasadniczo od charakterystyk obserwowanych na drodze doświadczalnej. Stosowane zabiegi matematyczne i numeryczne pozwalające na poprawę zgodności między obliczeniami a pomiarami okazują się skuteczne tylko w przypadku prostych rurociągów o stałej średnicy. Dla bardziej skomplikowanych przypadków prawidłowe odwzorowanie zjawiska...
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On bounded load routings for modeling k-regular connection topologies
PublicationW pracy analizowane są problemy modelowania k-regularnych topologii sieci komputerowych z punktu widzenia routingu typu point-to-point. Zaprezentowane są algorytmy oraz przeprowadzona jest analiza złożoności obliczeniowej.
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Soft modeling support for managing knowledge-based information technology (IT)
PublicationW pracy omówiono metody miękkiego modelowania. Wskazano na możliwości zastosowania tych metod do wspomagania tworzenia systemów opartych na wiedzy. Omówiono także metody oparte na teorii zbiorów rozmytych.
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Modeling of conducted emission of dc-dc switch-mode converter
PublicationW publikacji zaprezentowano sposób modelowania i wyznaczania emisji przewodzonej zaburzeń elektromagnetycznych w przekształtnikach energoelektronicznych. Na przykładzie przekształtnika DC-DC, zostały dobrane odpowiednie narzędzia CAD do szerokopasmowego modelowania i symulacji przekształtnika energoelektronicznego. Otrzymane rezultaty zostały eksperymentalnie potwierdzone i porównane zarówno w dziedzinie czasu jak i częstotliwości...
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Design and modeling of the piezoelectric motor based on three resonance actuators
PublicationThis paper describes a piezoelectric motor which combines advantages from two existing piezoelectric motors topologies. The research work presents the design, simulations and measurements of the piezoelectric motor with three rotation-mode actuators. The aim of the project was to obtain the high speed piezoelectric motor. Other advantages of this conception are blocking torque, short response times, the ability to work in a hostile...
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Reliable Microwave Modeling By Means of Variable-Fidelity Response Features
PublicationIn this work, methodologies for low-cost and reliable microwave modeling are presented using variable-fidelity response features. The two key components of our approach are: (i) a realization of the modeling process at the level of suitably selected feature points of the responses (e.g., S-parameters vs. frequency) of the structure at hand, and (ii) the exploitation of variable-fidelity EM simulation data, also for the response...
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Modeling of traffic safety indictors on Polish national road network
PublicationAlthough decreased from 2001 to 2013, Poland’s road deaths improved at a slower rate than the rest of the EU, leaving Poland as one of the worst road safety performing countries in the EU. The national road network in Poland, despite the dynamic transformation and development, still does not conform to the EU safety standards. Similar situation exists in other EU countries, particularly those in Central and Eastern Europe. Safety...
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Modeling of multi-cavity Fabry-Perot optical fiber sensors
PublicationReflectance characteristics of a two-cavity extrinsic Fabry-Perot optical fiber sensor were investigated using computer modeling. Calculations were performed using a plane wave-based approach, selected for clarity of results. Based on the modeling results, it can be concluded that the two-cavity Fabry-Perot interferometer can be used to measure two different quantities, such as refractive index and temperature, independently. It...
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Modeling of Ice Passage Through Reservoirs System on the Vistula River
PublicationNumerical model was used to assess ice passage through proposed reservoir on the lower Vistula River. Model results were compared with observation on the Vistula River, but because the dam is not constructed yet, the direct comparison was not possible. The study focused on ice movement and accumulation in the reservoir for variety of low flow condition with and without wind effect. Bridge’s piers in the upper part of the reservoir...
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Numerical modeling of sound intensity distributions around acoustic transducer
PublicationThe aim of this research study is to measure, simulate and compare sound intensity distribution generated by the acoustic transducers of the loudspeaker. The comparison of the gathered data allows for validating the numerical model of the acoustic radiation. An accurate model of a sound source is necessary in mathematical modeling of the sound field distribution near the scattering obstacles. An example of such obstacle is a human...
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Applicability of an effective conductivity approach in modeling thoracic impedance changes
PublicationThis paper describes numerical simulations of the influence of conductivity changes inside a volume conductor on impedance changes measured on its surface. A simple model based on the finite element method has been developed to estimate an applicability of the effective conductivity theory in human chest modeling. The model consisted of a cylinder with two concentric spheres inside. Simulations were performed for two cases: first...
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Improving performance of large thrust bearings through modeling and experimentation
PublicationLarge thrust bearings are highly loaded machine elements and their failures cause serious losses. Start ups and stoppages of the bearing under load are specially critical regimes of operation. Load carrying capacity depends on the profile of the oil gap. In transient states this profile is also changing. In the design of large thrust bearings minimizing thermo-elastic deformations is an important goal, which can be accomplished...
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Modeling Reservoir Gas Permeability Tests for Cylindrical and Spherical Geometry
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Modeling of broadband light source to use with optical coherenttomography system
PublicationW pracy przedstawiono modelowanie źródeł szerokopasmowych na potrzeby systemów koherentnej tomografii optycznej z punktu widzenia uzyskiwanej zdolności podłużnej i jakości otrzymywanych obrazów. Pokazano na przykładzie źródła szerokopasmowego wykorzystującego światłowód fotoniczny do generacji w wyniku zjawisk nieliniowych ''supercontinuum'' wpływ kształtowania wiązki na możliwości pomiarowe systemu OCT.
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Modeling of production planning and control process consistent with theory of constraint
PublicationArtykuł dotyczy problematyki zastosowania metody werbel-bufor-lina do planowania produkcji w systemach produkcyjnych z wielokrotnymi buforami. W artykule przedstawiono algorytm - jego funkcje, dane wejściowe i wyjściowe - który może mieć zastosowanie do modelowania procesu planowania i sterowania produkcją. Algorytm umożliwia określenie wielkości czasowych buforów w systemie oraz terminów rozpoczęcia i zakończenia realizacji zadań....
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Modeling SARS‐CoV‐2 proteins in the CASP‐commons experiment
PublicationCritical Assessment of Structure Prediction (CASP) is an organization aimed at advancing the state of the art in computing protein structure from sequence. In the spring of 2020, CASP launched a community project to compute the structures of the most structurally challenging proteins coded for in the SARS-CoV-2 genome. Forty-seven research groups submitted over 3000 three-dimensional models and 700 sets of accuracy estimates on...
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Modeling the Structure, Dynamics, and Transformations of Proteins with the UNRES Force Field
PublicationThe physics-based united-residue (UNRES) model of proteins ( www.unres.pl ) has been designed to carry out large-scale simulations of protein folding. The force field has been derived and parameterized based on the principles of statistical-mechanics, which makes it independent of structural databases and applicable to treat nonstandard situations such as, proteins that contain D-amino-acid residues. Powered by Langevin dynamics...
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Modeling and Evaluation of Electric Treeing Phenomena in Polymeric Cable Insulation
PublicationThis paper investigates the treeing phenomenon in polymeric materials such as crosslinked polyethylene (XLPE) that is widely used in medium and high voltage power cables as primary insulation. The modeling of electrical tree growth in the insulation from its initiation to breakdown is significant research work that illustrates the discharge dynamics and its impact on aging process in polymeric insulation. This study utilizes pulse...
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Global Surrogate Modeling by Neural Network-Based Model Uncertainty
PublicationThis work proposes a novel adaptive global surrogate modeling algorithm which uses two neural networks, one for prediction and the other for the model uncertainty. Specifically, the algorithm proceeds in cycles and adaptively enhances the neural network-based surrogate model by selecting the next sampling points guided by an auxiliary neural network approximation of the spatial error. The proposed algorithm is tested numerically...
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Mainstream shortcut N removal modeling current status and perspectives
PublicationThis work gives an overview of the state-of-the-art in modelling of short-cut processes for nitrogen removal in mainstream wastewater treatment and presents future perspectives for directing research efforts in line with the needs of practice. The modelling status for deammonification (i.e., anammox-based) and nitrite-shunt processes is presented with its challenges and limitations. The importance of mathematical models for considering...
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Wideband Modeling of DC-DC Buck Converter with GaN Transistors
PublicationThe general wideband modeling method of the power converter is presented on the example of DC-DC buck converter with GaN High Electron Mobility Transistors (HEMT). The models of all basic and parasitic components are briefly described. The two methods of Printed Circuit Board (PCB) layout parameter extraction are presented. The results of simulation in Saber@Sketch simulation software and measurements are compared. Next, the model...
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A Novel Approach to Fully Nonlinear Mathematical Modeling of Tectonic Plates
PublicationThe motion of the Earth's layers due to internal pressures is simulated in this research with an efficient mathematical model. The Earth, which revolves around its axis of rotation and is under internal pressure, will change the shape and displacement of the internal layers and tectonic plates. Applied mathematical models are based on a new approach to shell theory involving both two and three-dimensional approaches. It is the...
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SIMPLIFIED MODELING OF STRESS AND DEFLECTION LIMIT STATES OF UNDERGROUND TANKS
PublicationFuel tanks are designed with regard to standard actions and operating conditions. The work analyses the impact of corrosion and other means to variation of stresses and deformation of a horizontal underground tank shell. The computations are preliminary. Due to the long computational time of the entire tank the analysis is restricted to its part only. The full analysis is bound to assess structural reliability, further allowing...
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Modeling of luminance distribution in CAVE-type virtual reality systems
PublicationAt present, one of the most advanced virtual reality systems are CAVE-type (Cave Automatic Virtual Environment) installations. Such systems are usually consisted of four, five or six projection screens and in case of six screens arranged in form of a cube. Providing the user with a high level of immersion feeling in such systems is largely dependent of optical properties of the system. The modeling of physical phenomena plays nowadays...
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Modeling of lapping plate wear and conditioning in single-sided lapping
PublicationIn order to achieve higher quality on worked surfaces with lower roughness, very high accuracy of shape and dimensions it is crucial to improve conventional finishing technologies and to develop new working principles. Single-sided lapping is one of the most effective planarization technologies and it is determined by a number of factors and boundary conditions. The most significant influence over a dimensional and profile accuracy,...
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Modeling of the behavior of granular bodies using DEM with contact moments
PublicationW artykule przedstawiono wyniki symulacji badania trójosiowego dla materiałów granulowanych. Obliczenia wykonano przy zastosowaniu metody DEM. Pokazano wpływ momentów kontaktowych na wytrzymałość próbki. Zbadano wpływ parametrów mikroskopowych.
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Comparative modeling of shear localization in granular bodies with FEM and DEM
PublicationThe intention of the paper is to compare the calculations of shear zones in granular bodies using two different approaches: a continuum and a discrete one. In the first case, the FEM based on a micro-polar hypoplastic constitutive law was used. In the second case, the DEM was taken advantage of, where contact moments were taken into account to model grain roughness. The comparative calculations were performed for a passive case...
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Numerical modeling of shear localizations during granular flow in silos.
PublicationW artykule przedstawiono wyniki numerycznej analizy MES dotyczącej przepływów materiałów sypkich w silosach. Omówiono różne metody opisu lokalizacji odkształceń stycznych wewnątrz materiałów. Wyniki porónano z wynikami doświadczalnymi.
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Advances in Modelling and Analysis B: Signals, Information, Data, Patterns
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Influence of electric power generator structure on frequency control - mathematical modeliling
PublicationPodstawowym celem pakietu ''3x20'' Unii Europejskiej jest zmniejszenie o 20% emisji dwutlenku węgla. Z tego powodu oczekuje się w Polsce rozwoju energetyki wiatrowej, podobnie jak energetyki jądrowej, a także mini elektrociepłowni. Elektrownie wiatrowe i jądrowe wnoszą specyficzne problemy w regulacji automatycznej częstotliwości systemu elektroenergetycznego. farmy wiatrowe wymagają pod tym względem wspomagania przez elektrownie...
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25 kV–50 Hz railway supply modelling for medium frequencies (0–5 kHz)
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