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ACM Transactions on Modeling and Performance Evaluation of Computing Systems
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Energy Systems-Optimization Modeling Simulation and Economic Aspects
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Efektywność przewodowego transportu paliw gazowych. Część 1
PublicationW pracy przeprowadzono badanie możliwości podwyższenia efektywności transportu rurociągowego gazu ziemnego. Przeanalizowano różnorodne aspekty z zakresu procedur projektowania. Zaproponowano modele określania kosztów kapitałowych (inwestycyjnych) i kosztów zmiennych. Określono równania jednostkowych kosztów całkowitych (rocznych), które poddano „quasi-optymalizacji”, w celu wyznaczenia średnic racjonalnych dla gazociągów.
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Efektywność przewodowego transportu paliw gazowych. Część 2
PublicationW pracy przeprowadzono badanie możliwości podwyższenia efektywności transportu rurociągowego gazu ziemnego. Przeanalizowano różnorodne aspekty z zakresu procedur projektowania. Zaproponowano modele określania kosztów kapitałowych (inwestycyjnych) i kosztów zmiennych. Określono równania jednostkowych kosztów całkowitych (rocznych), które poddano „quasi-optymalizacji”, w celu wyznaczenia średnic racjonalnych dla gazociągów.
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Modelling of a medium-term dynamics in a shallow tidal sea, based on combined physical and neural network methods
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Combining Satellite Imagery and Numerical Modelling to Study the Occurrence of Warm Upwellings in the Southern Baltic Sea in Winter
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Effect of GIS parameters on modelling runoff from river basin. The case study of catchment in the Puck District
PublicationThe study was preceded to check the impact of the adopted digital elevation model resolution on the determination of catchment parameters and the further influence of the received information on calculations related to the hydrograph at the closing point of the basin after a synthetic 100-year precipitation episode. The study area are river basins located in the Puck commune convoying water directly to the Puck Bay. These studies...
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Design-oriented computationally-efficient feature-based surrogate modelling of multi-band antennas with nested kriging
PublicationDesign of modern antenna structures heavily depends on electromagnetic (EM) simulation tools. EM analysis provides reliable evaluation of increasingly complex designs but tends to be CPU intensive. When multiple simulations are needed (e.g., for parameters tuning), the aggregated simulation cost may become a serious bottleneck. As one possible way of mitigating the issue, the recent literature fosters utilization of faster representations,...
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Low-cost performance-driven modelling of compact microwave components with two-layer surrogates and gradient kriging
PublicationUtilization of electromagnetic (EM) simulation tools has become indispensable for reliable evaluation of microwave components. As the cost of an individual analysis may already be considerable, the computational overhead associated with EM-driven tasks that require massive simulations (e.g., optimization) may turn prohibitive. One of mitigation methods is the employment of equivalent network models. Yet, they are incapable of accounting...
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Sensitivity analysis based on non-intrusive regression-based polynomial chaos expansion for surgical mesh modelling
PublicationThe modelling of a system containing implants used in ventral hernia repair and human tissue suffers from many uncertainties. Thus, a probabilistic approach is needed. The goal of this study is to define an efficient numerical method to solve non-linear biomechanical models supporting the surgeon in decisions about ventral hernia repair. The model parameters are subject to substantial variability owing to, e.g., abdominal wall...
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Risk Modelling with Bayesian Networks - Case Study: Construction of Tunnel under the Dead Vistula River in Gdansk
PublicationThe process of decision-making in public procurement of construction projects during the preparation and implementation phases ought to be supported by risk identification, assessment, and management. In risk assessment one has to take into account factors that lead to risk events (background info), as well as the information about the risk symptoms (monitoring info). Typically once the risks have been assessed a decision-maker...
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Modelling of saturated, subcooled and post-dryout flow boiling with the energy dissipation based semi-empirical model
PublicationA comprehensive semi-empirical model for saturated, subcooled and post dryout heat transfer is presented based on considerations of energy dissipation in the flow. The fundamental hypothesis in the model is the fact that heat transfer during flow boiling can be treated as a sum of two contributions constituting the total energy dissipation in the flow, namely the energy dissipation due to the shearing flow without the bubbles and...
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Heavy Duty Vehicle Fuel Consumption Modelling Based on Exploitation Data by Using Artificial Neural Networks
PublicationOne of the ways to improve the fuel economy of heavy duty trucks is to operate the combustion engine in its most efficient operating points. To do that, a mathematical model of the engine is required, which shows the relations between engine speed, torque and fuel consumption in transient states. In this paper, easy accessible exploitation data collected via CAN bus of the heavy duty truck were used to obtain a model of a diesel...
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A performance-oriented risk-based method for assessment of safety of ships. Modelling uncertainties in hazard and risk analysis
PublicationW artykule podano informacje na temat alternatywnej metody oceny bezpieczeństwa statków, opartej na ocenie zachowania się statku i ocenie ryzyka. Zaproponowano użycie metody do projektowania statków w oparciu o ocenę ryzyka. W takim podejściu do projektowania bezpieczeństwo powinno być celem projektowym. Ocena bezpieczeństwa w proponowanej metodzie powinna być dokonywana na podstawie oceny ryzyka. Do oceny ryzyka zastosowano elementy...
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Modelling the Kerf Angle, Roughness and Waviness of the Surface of Inconel 718 in an Abrasive Water Jet Cutting Process
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Groundwater flow modelling of multi-aquifer systems for regional resources evaluation: the Gdansk hydogeological system, Poland
PublicationW celu oceny regionalnych zasobów gdańskiego systemu hydrogeologicznego zbudowano matematyczny model przepływu wód. Obszar badań objął około 2800 km2. Dane pozyskano z ponad 1700 otworów badawczych. Na podstawie modelu oszacowano zasoby dla wszystkich pieter wodonośnych: plejstoceńskiego, neogeńsko-paleogeńskiego i kredowego. Na podstawie analizy równania Bredehoef'a ustalono, że aktualna eksploatacja jest zbliżona do poziomu ''zrównoważonego...
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Flavonoids as tyrosinase inhibitors in in silico and in vitro models: basic framework of SAR using a statistical modelling approach
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Modelling the Viability of Microorganisms of Poly(lactic Acid) Melt-Blown Nonwoven Fabrics for the Use of Respiratory Protection
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Alkali-activated slag supplemented with waste glass powder: Laboratory characterization, thermodynamic modelling and sustainability analysis
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The Reliability and Exploitation Analysis Method of the ICT System Power Supply with the Use of Modelling Based on Rough Sets
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Mechanical response of 6061-T6 aluminium alloy subjected to dynamic testing at low temperature: Experiment and modelling
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Derivation of the scaling laws used in geotechnical centrifuge modelling-application of dimensional analysis and Buckingham Π theorem
PublicationGeotechnical centrifuge modelling has been a world-wide used technology in physical tests. In this paper a derivation of scaling laws by dimensional analysis for the centrifugal modelling is presented. Basic principles of centrifuge modelling are described. Scaling laws for slow events like consolidation and fast events like dynamic loads are shown. The differences in scale factors for both processes are noticed. The aim of this...
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Evaluation and behaviour of slowly biodegradable substrate on mathematical modelling of oxygen uptake rate in activated sludge systems
PublicationThe effect of the readily biodegradable (Ss) fraction in activated sludge systems has been extensively investigated, but only minor information can be found about the effect of Xs on OUR in activated sludge systems. The aim of this study was to determine the evaluation and behaviour of Xs on mathematical modelling of OUR using ASM2d and its modification. The essential study was divided into two major parts: experimental investigation...
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Modelling of the High Speed Multi-Pole Synchronous Generator for Application in More Electric Aircraft Power Systems
PublicationIn this paper different models of the synchronous generator are presented. The simulation results compared with the measurements are shown. Certain physical phenomena are included in described models for the porpoise of adequate analysis of the more electric aircraft power system. For different modelling levels, such as functional level or behavioural level, different physical phenomena have been included. Simulation results for...
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Problems of modelling toxic compounds emitted by a marine internal combustion engine for the evaluation of its structure parameters
PublicationThe paper presents the possibility of using an analytical study of the engine exhaust ignition to evaluate the technical condition of the selected components. Software tools available for the analysis of experimental data commonly use multiple regression model that allows the study of the effects and iterations between model input quantities and one output variable. The use of multi-equation models gives a lot of freedom in the...
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Interaction Between Storm Water Conduit Flow and Overland Flow for Numerical Modelling of Urban Area Inundation
PublicationNowadays we can observe increasing frequency of inundations in cities. This makes accurate predicting of inundations more important than ever. Numerical modeling of this issue requires complex approach with simultaneous calculations of pipe flow and surface flow. In this paper, after a short review of known methods used for solving pipe and surface flow, we will try to answer the question if presented methods would be sufficiently...
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Modelling long-term technological transition of Polish power system using MARKAL: Emission trade impact
PublicationThe need for technological transition of electricity production becomes a global problem. However, in coal-dominated Polish power system this need is even more crucial than anywhere, since technical lifetime of the most domestic power plants is ending. In this paper, the impact of the EU Emission Trading Scheme (EU ETS) for CO2 combined with sulfur dioxide (SO2) and nitrogen oxides (NOx) emission trading mechanism on power technology...
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Modelling and Control of a Brushless Multiphase Doubly-Fed Induction Generator in a Stand-Alone Wind Generation System
PublicationThe development of the novel multiphase brushless doubly-fed generator system and voltage controller for stand-alone mode configuration is proposed in this paper. The generator system is based on the new machine construction with multiphase control winding and traditional three-phase power winding. The dynamic model of multiphase brushless doubly-fed generator is presented, and the control strategy for voltage amplitude and frequency...
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Sustainable nitrogen removal in anammox-mediated systems: Microbial metabolic pathways, operational conditions and mathematical modelling
PublicationAnammox-mediated systems have attracted considerable attention as alternative cost-effective technologies for sustainable nitrogen (N) removal from wastewater. This review comprehensively highlights the importance of understanding microbial metabolism in anammox-mediated systems under crucial operation parameters, indicating the potentially wide applications for the sustainable treatment of N-containing wastewater. The partial...
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FE-modelling of concrete behaviour under mixed mode conditions with non-local and cohesive constitutive models.
PublicationW artykule przedstawiono wyniki symulacji rys zaokrąglonych w elementach betonowych w warunkach mieszanego sposobu obciążenia. Symulacje wykonano przy zastosowaniu modelu rys kohezyjnych i modeli mechaniki ośrodka ciągłego z nielokalnym osłabieniem.. Wyniki symulacji porównano z doświadczeniami.
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Modelling reinforced concrete beams under mixed shear-tension failure with different continuous FE approaches
PublicationThe paper presents quasi-static numerical simulations of the behaviour of short reinforced concrete beams without shear reinforcement under mixed shear-tension failure using the FEM and four various constitutive continuum models for concrete. First, an isotropic elasto-plastic model with a Drucker-Prager criterion defined in compression and with a Rankine criterion defined in tension was used. Next, an anisotropic smeared crack...
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Modelling of reinforced concrete beams under mixed shear-tension failure with different continuous FE approaches
PublicationW artykule omówiono wyniki modelowania numerycznego MES zachowania się wysokich belek żelbetowych podczas zniszczenia mieszanego ścinanie-rozciąganie. Obliczenia wykonano stosując różne modele dla betonu rozszerzone o długość charakterystyczną mikrostruktury w oparciu o teorie nielokalna. Otrzymano dobrą zgodność z wynikami doświadczalnymi.
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Micro-modelling of shear localization during quasi-static confined granular flow in silos using DEM
PublicationThe paper deals with the quasi-static confined flow of cohesionless sand in a plane strain model silo with parallel walls and a slowly movable bottom. Numerical modelling was carried out by the discrete element method (DEM) using spheres with contact moments to approximately capture a non-uniform shape of sand particles. Different initial void ratios of sand and silo wall roughness grades were employed. Regular triangular grooves...
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Modelling of Capillary Pressure-driven Water Flow in Unsaturated Concrete Using Coupled DEM/CFD Approach.
PublicationSformułowano nowatorskie, połączone podejście do modelowania dwufazowego przepływu wody napędzanego kapilarami w nienasyconym betonie. Dzięki połączeniu metody elementów dyskretnych (DEM) z obliczeniową dynamiką płynów (CFD) w warunkach izotermicznych proces został zbadany numerycznie w mezoskali w warunkach dwuwymiarowych. Niewielkie próbki betonu o uproszczonej mezostrukturze cząstek poddano w pełni sprzężonym hydromechanicznym...
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Sławomir Jerzy Ambroziak dr hab. inż.
PeopleSławomir J. Ambroziak was born in Poland, in 1982. He received the M.Sc., Ph.D. and D.Sc. degrees in radio communication from Gdańsk University of Technology (Gdańsk Tech), Poland, in 2008, 2013, and 2020 respectively. Since 2008 he is with the Department of Radiocommunication Systems and Networks of the Gdańsk Tech: 2008-2013 as Research Assistant, 2013-2020 as Assistant Professor, and since 2020 as Associate Professor. He is...
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<title>Modeling of noncontact temperature measurement system using multiwavelength pyrometry</title>
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Modeling of Imaging Mass Spectrometry Data and Testing by Permutation for Biomarkers Discovery in Tissues
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Signal Partitioning Algorithm for Highly Efficient Gaussian Mixture Modeling in Mass Spectrometry
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Nuclear Power Plant Steam Turbine - Modeling for Model Based Control Purposes
PublicationThe nature of the processes taking place in a nuclear power plant (NPP) steam turbine is the reason why their modeling is very difficult, especially when the model is intended to be used for on-line optimal model based process control over a wide range of operating conditions, caused by changing electrical power demand e.g. when combined heat and power mode of work is utilized. The paper presents three nonlinear models of NPP steam...
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THE CONCEPT OF MODELING OF SNOW IMPACT ON THE STRUCTURE OF THE SUSPENDED TAURON ARENA ROOF IN CRACOW
PublicationThe 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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Recent advances in high-frequency modeling by means of domain confinement and nested kriging
PublicationDevelopment of modern high-frequency components and circuits is heavily based on full-wave electromagnetic (EM) simulation tools. Some phenomena, although important from the point of view of the system performance, e.g., EM cross-coupling effects, feed radiation in antenna arrays, substrate anisotropy, cannot be adequately accounted for using simpler means such as equivalent network representations. Consequently, the involvement...
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Low-Cost Surrogate Modeling of Miniaturized Microwave Components Using Nested Kriging
PublicationIn the paper, a recently reported nested kriging methodology is employed for modeling of miniaturized microwave components. The approach is based on identifying the parameter space region that contains high-quality designs, and, subsequently, rendering the surrogate in this subset. The results obtained for a miniaturized unequal-power-split rat-race coupler and a compact three-section impedance transformer demonstrate reliability...
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Modeling an Industrial Revolution: How to Manage Large-Scale, Complex IoT Ecosystems?
PublicationAdvancements around the modern digital industry gave birth to a number of closely interrelated concepts: in the age of the Internet of Things (IoT), System of Systems (SoS), Cyber-Physical Systems (CPS), Digital Twins and the fourth industrial revolution, everything revolves around the issue of designing well-understood, sound and secure complex systems while providing maximum flexibility, autonomy and dynamics. The aim of the...
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Antenna Modeling Using Variable-Fidelity EM Simulations and Constrained Co-Kriging
PublicationUtilization of fast surrogate models has become a viable alternative to direct handling of fullwave electromagnetic (EM) simulations in EM-driven design. Their purpose is to alleviate the difficulties related to high computational cost of multiple simulations required by the common numerical procedures such as parametric optimization or uncertainty quantification. Yet, conventional data-driven (or approximation) modeling techniques...
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Modeling of Transient Photocurrent in Organic Semiconductors Incorporating the Annihilation of Excitons on Charge Carriers
PublicationThe role of the annihilation of excitons on charge carriers has been theoretically investigated in organic semiconductors. We have developed the numerical drift-diffusion model by incorporation terms which describe the annihilation process. The transient photocurrent has been calculated for different injection barrier heights, exciton mobilities, and annihilation rate constants. We have demonstrated that the annihilation has a...
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Modeling a Traffic Remapping Attack Game in a Multi-hop Ad Hoc Network
PublicationIn multi-hop ad hoc networks, selfish nodes may unduly acquire high quality of service (QoS) by assigning higher priority to source packets and lower priority to transit packets. Such traffic remapping attacks (TRAs) are cheap to launch, impossible to prevent, hard to detect, and harmful to non-selfish nodes. While studied mostly in single-hop wireless network settings, TRAs have resisted analysis in multi-hop settings. In this paper...
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Accelerated multi-objective design optimization of antennas by surrogate modeling and domain segmentation
PublicationMulti-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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Rapid dimension scaling of triple-band antennas by means of inverse surrogate modeling
PublicationGeometry scaling of antennas, i.e., finding optimum dimensions of the structure for given operating conditions and material parameters is an important yet challenging problem. In this paper, we discuss fast dimension scaling of triple-band antennas with respect to operating frequencies. We adopt the inverse surrogate modeling approach where the surrogate model is a function of the three operating frequencies of the antenna and...
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Key issues in modeling and optimization of lignocellulosic biomass fermentative conversion to gaseous biofuels
PublicationThe industrial-scale production of lignocellulosic-based biofuels from biomass is expected to benefit society and the environment. The main pathways of residues processing include advanced hydrolysis and fermentation, pyrolysis, gasification, chemical synthesis and biological processes. The products of such treatment are second generation biofuels. The degree of fermentation of organic substances depends primarily on their composition...
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Modeling protein structures with the coarse-grained UNRES force field in the CASP14 experiment
PublicationThe UNited RESidue (UNRES) force field was tested in the 14th Community Wide Experiment on the Critical Assessment of Techniques for Protein Structure Prediction (CASP14), in which larger oligomeric and multimeric targets were present compared to previous editions. Three prediction modes were tested (i) ab initio (the UNRES group), (ii) contact-assisted (the UNRES- contact group), and (iii) template-assisted (the UNRES-template...