Filters
total: 9933
-
Catalog
- Publications 9055 available results
- Journals 8 available results
- Conferences 8 available results
- People 96 available results
- Inventions 1 available results
- Projects 12 available results
- Research Equipment 8 available results
- e-Learning Courses 96 available results
- Events 5 available results
- Open Research Data 644 available results
displaying 1000 best results Help
Search results for: model order reduction
-
Implicit difference methods for nonlinear first order partial differential equations
PublicationW pracy klasyczne rozwiązania początkowo brzegowych problemów dla nieliniowych równań różniczkowych, szacowane są przez rozwiązania quasiliniowych układów uwikłanych równań różnicowych. Dowód zbieżności rozważanych metod opiera się na technice porównawczej z nieliniowym oszacowaniem typu Perrona dla funkcji danych. To nowe podejście do uwikłanych metod różnicowych dla równań nieliniowych opiera się na quasilinearyzacji tych metod...
-
Boundary value problems for first order differential equations of mixed type
PublicationPraca dotyczy równań różniczkowo-całkowych z nieliniowymi warunkami brzegowymi. Podano warunki dostateczne na istnienie jedynego rozwiązania oraz rozwiązań ekstremalnych takich problemów. Dyskutowane są nierówności różniczkowo-całkowe. Podano przykłady ilustrujące otrzymane wyniki teoretyczne.
-
Method of lines for nonlinear first order partial functional differential equations.
PublicationClassical solutions of initial problems for nonlinear functional differential equations of Hamilton--Jacobi type are approximated by solutions of associated differential difference systems. A method of quasilinearization is adopted. Sufficient conditions for the convergence of the method of lines and error estimates for approximate solutions are given. Nonlinear estimates of the Perron type with respect to functional variables...
-
Low order autoregressive (AR) models for FDTD analysis of microwave filters.
PublicationArtykuł opisuje zastosowanie modeli AR w celu poprawy efektywności analizy struktur filtrujących metodą różnic skończonych w dziedzinie czasu (FD-TD). Opisanych jest szereg kryteriów pozwalających na automatyczne tworzenie modeli AR sygnałów czasowych, w tym wybór fragmentu odpowiedzi układu stanowiący podstawę ekstrakcji współczynników modelu, współczynnika decymacji oraz rzędu modelu. Skuteczność wprowadzonych kryteriów...
-
Numerical method of lines for first order partial differential functional equations
PublicationUdowodniono zbieżność numerycznej metody prostych dla równań różniczkowofunkcyjnych o pochodnych cząstkowych pierwszego rzędu i ich rozwiązań klasycznych określonych na piramidzie Haara. Zastosowano metodę nierówności różniczkowych.
-
Numerical approximation of first order partial differential equations withdeviated variables.
PublicationKlasyczne rozwiązania nieliniowego zagadnienia Cauchy´ego określone na piramidzie Haara są aproksymowane za pomocą rozwiązań układów quasiliniowych równań różnicowych. Stabilność schematu różnicowego jest wykazana metodą porównawczą z zastosowaniem nieliniowych oszacowań typu Perrona dla danych funkcji. Podano przykłady numeryczne.
-
Finite difference approximations for nonlinear first order partial differential equations
PublicationKlasyczne rozwiązania nieliniowych równań różniczkowych o pochodnych cząst-kowych pierwszego rzędu są aproksymowane za pomocą równań quasiliniowych uk-ładów równań różniczkowych. Dowód zbieżności wykorzystuje metody porównawcze
-
Generalized Euler method for nonlinear first order partial differential equations.
PublicationKlasyczne rozwiązania nieliniowych równań różniczkowych cząstkowych pierwszego rzędu są aproksymowane w tej pracy za pomocą rozwiązań quasiliniowych układów równań różnicowych. Podstawowa idea pracy jest oparta na teorii charakterystyk. Podane są warunki wystarczające dla zbieżności metody. Dowód stabilności schematu różnicowego wykorzystuje metodę porównawczą z nieliniowymi oszacowaniami typu Perrona dla danych funkcji.Podane...
-
A Wideband Channel Model for Body Area Networks in Circular Metallic Indoor Environments
PublicationIn this paper, the wideband characterization of the propagation channel in circular metallic indoor environments is addressed, regarding Body Area Networks and 5G small cells, an analytical model for the dependence of the mean delay and the average delay spread on the circle radius, the working frequency and the distance between the transmitter and the receiver being proposed. The derivation of the model is initially done analytically,...
-
Precipitation of calcium carbonate in the presence of rhamnolipids in alginate hydrogels as a model of biomineralization
PublicationThis paper reports the effects of rhamnolipids presence in the alginate hydrogel and CO32- solution, on the precipitation of CaCO3 in the Ca2+ loaded alginate hydrogel. Characteristics of the formed particles are discussed. Model conditions containing alginate hydrogel and rhamnolipids were used in order to mimic the natural environment of biomineralization in biofilms. It has been shown that rhamnolipids affect the characteristics...
-
Adaptive CAD-Model Construction Schemes
PublicationTwo advanced surrogate model construction techniques are discussed in this paper. The models employ radial basis function (RBF)interpolation scheme or artificial neural networks (ANN) with a new training algorithm. Adaptive sampling technique is applied withrespect to all variables. Histograms showing the quality of the models are presented. While the quality of RBF models is satisfactory, theperformance of the ANN models obtained...
-
Stałoprądowy model tranzystora typu HSD MAGFET
PublicationZaproponowano stałoprądowy model dwudrenowego tranzystora polowego typu HSD MAGFET, wykorzystywanego jako czujnik pola magnetycznego o dużej czułości na zmiany pola magnetycznego i dużej geometrycznej rozdzielczości pomiarowej. Zaprezentowany model odzwierciedla zjawisko podziału prądu płynącego w kanale tranzystora na prądy drenów i uwzględnia wzajemne oddziaływanie napięć drenów VDS1 i VDS2 na prady drenów ID1 i ID2 poprzez wprowadzenie...
-
Nieliniowy model matematyczny transformatora trójfazowego = Non-linear mathematical model of a three-phase transformer
PublicationPrzedstawiono model transformatora trójfazowego o rdzeniu trójkolumnowym, który zawiera układ rów-nań opisujących obwód magnetyczny oraz oddzielnie układ równań obwodu elektrycznego. Wydzielenie re-luktancji elementów rdzenia umożliwia uwzględnienie zmian względnej przenikalności magnetycznej w funkcji bieżącej wartości strumienia w rdzeniu. Re-luktancje odpowiadające strumieniom rozproszenia obliczono wg zasad klasycznych. Funkcję...
-
Stress–strain model of lower corroded steel plates of normal strength for fitness-for-purpose analyses
PublicationThis study investigates the mechanical properties of specimens made of normal strength steel subjected to lower marine immersed corrosion degradation levels (below 25 %). The specimens were corroded in laboratory conditions, and only natural factors were controlled to raise the corrosion rate (reaching the level of 1 mm/year). Three different thicknesses of plates made of normal strength of shipbuilding steel are investigated (between...
-
A decentralised model of the regulating ancillary services market
PublicationThe article presents a model of regulating ancillary services provision in a dencetralised manner. A concept of the operation of local markets for ancillary services is presented.
-
Zdecentralizowany model rynku regulacyjnych usług systemowych
PublicationZaprezentowano model pozyskania regulacyjnych usług systemowych w sposób zdecentralizowany. Przedstawiono koncepcję funkcjonowania lokalnych rynków usług regulacyjnych.
-
Morse decompositions for a two-dimensional discrete neuron model (low resolution)
Open Research DataThis dataset contains selected results of rigorous numerical computations conducted in the framework of the research described in the paper “Topological-numerical analysis of a two-dimensional discrete neuron model” by Paweł Pilarczyk, Justyna Signerska-Rynkowska and Grzegorz Graff. A preprint of this paper is available at https://doi.org/10.48550/arXiv.2209.03443.
-
Morse decompositions for a two-dimensional discrete neuron model (limited range)
Open Research DataThis dataset contains selected results of rigorous numerical computations conducted in the framework of the research described in the paper “Topological-numerical analysis of a two-dimensional discrete neuron model” by Paweł Pilarczyk, Justyna Signerska-Rynkowska and Grzegorz Graff. A preprint of this paper is available at https://doi.org/10.48550/arXiv.2209.03443.
-
Morse decompositions for a two-dimensional discrete neuron model (full range)
Open Research DataThis dataset contains selected results of rigorous numerical computations conducted in the framework of the research described in the paper “Topological-numerical analysis of a two-dimensional discrete neuron model” by Paweł Pilarczyk, Justyna Signerska-Rynkowska and Grzegorz Graff. A preprint of this paper is available at https://doi.org/10.48550/arXiv.2209.03443.
-
Conceptual fuzzy model of the polish internet mortgage market
PublicationThe aim of this paper is to present the conceptual structure of basic fuzzy model representing Polish Internet mortgage market. The paper starts with introduction describing the market complexities and challenges, and description of previously created rule based model. Then the steps of the process of proposed model fuzzyfication are presented. Final part of the paper consists of conclusions and directions for future research.
-
Impedance spectra of RC model as a result of testing pulse excitation measurement method
Open Research DataThe impedance spectrum of RC model object obtained using pulse excitation EIS impedance spectrosocpy measurement method. The 1V voltage pulse excitation duration was set to 0.1s and the total acqusition time was set to 1000s. The object under test was built using RC components connected as Baunier model of anticorrosion coating with the following components...
-
Model-based identification of the dominant N2O emission pathway in a full-scale activated sludge system
PublicationActivated sludge models (ASMs), extended with an N2O emission module, are powerful tools to describe the operation of full-scale wastewater treatment plants (WWTPs). Specifically, such models can investigate the most contributive N2O production pathways and guide towards N2O and carbon footprint (CF) mitigation measures. A common practice is to develop and validate models using data from a single WWTP. In this study, a successfully...
-
Model osobistej wirtualnej biblioteki cyfrowej
PublicationSzybki rozwój Internetu umożliwiający publikowanie i czytanie artykułów online w skali globalnej, uzasadnia tworzenie bibliotek cyfrowych jako repozytoriów wiedzy. Ich rozwój napotyka jednak na liczne bariery natury psychologicznej, organizacyjnej i technologicznej. W artykule przedstawimy propozycje ich przełamania z punktu widzenia doświadczeń Biblioteki Głównej Politechniki Gdańskiej. W szczególności skoncentrujemy się na modelu...
-
A calibration model for gas sensor array in varying environmental conditions
PublicationAbstract: Gas-analyzing systems based on gas sensors, commonly referred to as electronic noses, are the systems which enable the recognition of volatile compounds in their working environment and provide the on-line results of analysis. The most commonly used type of sensors in such systems is semiconductor gas sensors. They are considered to be the most reliable in the long-term applications (more than 1 year), however,...
-
A calibration model for gas sensor array in varying environmental conditions
PublicationAbstract: Gas-analyzing systems based on gas sensors, commonly referred to as electronic noses, are the systems which enable the recognition of volatile compounds in their working environment and provide the on-line results of analysis. The most commonly used type of sensors in such systems is semiconductor gas sensors. They are considered to be the most reliable in the long-term applications (more than 1 year), however,...
-
Nowy empiryczny model propagacjny RTK
PublicationW referacie opisano i przeanalizowano nowy model empiryczny do szacowania tłumienia propagacyjnego w ruchomych łączach radiowych pracujących w środowisku terminalu kontenerowego. Na wstępie opisane zostały badania pomiarowe przeprowadzone w celu uzyskania danych empirycznych pozwalających na opracowanie nowego modelu oraz scharakteryzowano badane środowisko. W głównej części referatu omówiono postać analityczną modelu oraz przedstawiono...
-
Model tworzenia wartości w logistyce
PublicationWażnym zadaniem zarządzania logistycznego jest budowanie przewagi konkurencyjnej przedsiębiorstwa na bazie zdolności łańcucha dostaw (łańcucha logistycznego) do tworzenia wartości. Osiągnięcie oczekiwanego poziomu wzrostu wartości w procesach logistycznych wymaga połączenia wartości z użytecznością, szybkością działania i efektywnością kosztową. W pracy przedstawiono model procesu tworzenia wartości w działaniach logistycznych,...
-
Multisource model of ship electric field
PublicationA steel-hulled ship in sea water produces an electric field around itself. The source of this field are electrochemical processes and ship's cathodic protection. The analysis of the electric field around the ship is important by the reason of the ship's identification and counter-mine protection. The paper presents a simplified model of the ship's multisource electric field, which allows to calculate the electric field distribution...
-
Information retrieval with semantic memory model
PublicationPsycholinguistic theories of semantic memory form the basis of understanding of natural language concepts. These theories are used here as an inspiration for implementing a computational model of semantic memory in the form of semantic network. Combining this network with a vector-based object-relation-feature value representation of concepts that includes also weights for confidence and support, allows for recognition of concepts...
-
Model rozmyty zarządzania przedsięwzięciami informatycznymi.
PublicationPrzedstwiono budowę samonastrajalnego modelu rozmytego zarządzania przedsięwzięciami informatycznymi, który będzie wykorzystywany do wspomagania wytwarzania systemów opartych na wiedzy. Proponowany model bazuje on na rozwiązaniach opartych na wiedzy oraz teorii systemów dynamicznych i zbiorów rozmytych. W szczegółowej konstrukcji wykorzystano wiedzę dotyczącą zarządzania rzeczywistymi przedsięwzięciami informatycznymi (PATRIC i...
-
How to apply the probabilistic model of measurement processes successfully
PublicationApplicational aspects of probabilistic model of measurement processes, proposed by G.B. Rossi, are considered. The main idea of the model - using of Bayes-Laplace postulate for solution of inverse probability problem, is substituted by Fisher's concept of the likelihood function, expressed in the data translated format. This approach gives a clear-sighted solution of inverse probability. Some recommendations for application of...
-
Three-dimensional conceptual model for service-oriented simulation
Publicationn this letter, we propose a novel three-dimensional conceptual model for an emerging service-oriented simulation paradigm. The model can be used as a guideline or an analytic means to find the potential and possible future directions of the current simulation frameworks. In particular, the model inspects the crossover between the disciplines of modeling and simulation, service-orientation, and software/systems engineering. Finally,...
-
Mariusz Kaczmarek dr hab. inż.
PeopleReceived M.Sc., Eng. in Electronics in 1995 from Gdansk University of Technology, Ph.D. in Medical Electronics in 2003 and habilitation in Biocybernetics and Biomedical Engineering in 2017. He was an investigator in about 13 projects receiving a number of awards, including four best papers, practical innovations (7 medals and awards) and also the Andronicos G. Kantsios Award and Siemens Award. Main research activities: the issues...
-
Fine-Tuning the Photocatalytic Activity of the Anatase {1 0 1} Facet through Dopant-Controlled Reduction of the Spontaneously Present Donor State Density
PublicationThe present study highlights the importance of the net density of charge carriers at the ground state on photocatalytic activity of the faceted particles, which can be seen as a highly underexplored problem. To investigate it in detail, we have systematically doped {1 0 1} enclosed anatase nanoparticles with Gd3+ ions to manipulate the charge carrier concentration. Furthermore, control experiments using an analogical Nb5+ doped...
-
A Numerical Model Study on Ice Boom in a Coastal Lake
PublicationA numerical study on the effectiveness of the proposed ice boom to be installed near the entrance of Lake Notoro, Hokkaido, Japan to prevent sea ice moving into the lake is presented. A two-dimensional hydro–ice dynamics model was modified to allow for the treatment of ice-boom interaction with the effect of tidal current. The numerical model is a coupled hydrodynamic and ice dynamic model. The ice dynamic component uses a Lagrangian...
-
Practical Use of Generic IT Organization Evolution Model
PublicationIn the paper we analyze, basing on the practical experiences, how the Generic IT Organization Model could be used to describe evolution of real-world IT support organization in relation to IT Service Management area.
-
Fast multi-objective optimization of antenna structures by means of data-driven surrogates and dimensionality reduction
PublicationDesign of contemporary antenna structures needs to account for several and often conflicting objectives. These are pertinent to both electrical and field properties of the antenna but also its geometry (e.g., footprint minimization). For practical reasons, especially to facilitate efficient optimization, single-objective formulations are most often employed, through either a priori preference articulation, objective aggregation,...
-
Application of MARKAL model to optimisation of electricity generation structure in Poland in the long-term time horizon. Part II. Model and forecasts assumptions
PublicationIn this paper, the next in a series of publications on the subject, assumptions are presented of a power system development model in terms of electricity generation technology infrastructure in Poland, in the long term perspective until 2060. The model is based on the mathematical structure of the MARKAL optimization package. Among other things developed are a forecast of the final demand for electricity and heat, the current...
-
In Situ Verification of Numerical Model of Water Hammer in Slurries
PublicationThis paper presents a numerical model of transient flow in a pressure slurry pipeline network with verification based on in situ measurements. The model, primarily verified in laboratory conditions, has been extended and applied to the case of a large and complex slurry pipeline network in Poland. In the model, the equivalent density concept was applied. In situ experiments were performed for various unsteady flow episodes, caused by...
-
Bending analysis of functionally graded nanoplates based on a higher-order shear deformation theory using dynamic relaxation method
PublicationIn this paper, bending analysis of rectangular functionally graded (FG) nanoplates under a uniform transverse load has been considered based on the modified couple stress theory. Using Hamilton’s principle, governing equations are derived based on a higher-order shear deformation theory (HSDT). The set of coupled equations are solved using the dynamic relaxation (DR) method combined with finite difference (FD) discretization technique...
-
St. Adalberd church 3D point model
Open Research DataResearch data show the church of St. Adalbert in Gdansk, Poland. Two layers are presented in the .zip file: one represents the laser scanning result, the second represents the point cloud from 36 photogrammetry images from the UAV system. The aligned point clouds formed the basis to create the high-resolution 3D model. Reference data are laser scanning...
-
Development and validation of lumbar spine finite element model
PublicationThe functional biomechanics of the lumbar spine have been better understood by finite element method (FEM) simulations. However, there are still areas where the behavior of soft tissues can be better modeled or described in a different way. The purpose of this research is to develop and validate a lumbar spine section intended for biomechanical research. A FE model of the 50th percentile adult male (AM) Total Human Model for Safety...
-
A concept of heterogeneous numerical model of concrete for GPR simulations
PublicationThe Ground Penetrating Radar (GPR) method, which is increasingly being used in the non-destructive diagnostics of reinforced concrete structures, often needs more accurate interpretation tools for analysis of experimental data. Recently, there has been growing interest in developing of various numerical models for exhaustive understanding of GPR data. This paper presents the concept of a heterogeneous numerical model of concrete,...
-
Sustainable Knowledge Sharing Model for IT Agile Projects
PublicationIn order to overcome work environment challenges and remain competitive in the market, organisations must adapt. An organisation's competitiveness can be improved through knowledge sharing; however, improvement without responsibility can have a negative impact on the sociotechnical environment which people cannot fully comprehend. According to researchers, business involvement in sustainable development goals remains minimal [51]....
-
Determination of Mathematical Model Parameters of a Medium Frequency Transformer
PublicationThe paper presents the results of experimental studies of the medium frequency transformer. The object of the research was a prototype of a single-phase transformer with a core made of ferrite I-core elements and windings made of Litz conductors. The research was carried out to determine the parameters of the transformer's mathematical model. The scope of the tests included determining the magnetic hysteresis loop and measuring...
-
Spike patterns and chaos in a map-based neuron model
PublicationThe work studies the well-known map-based model of neuronal dynamics introduced in 2007 by Courbage, Nekorkin and Vdovin, important due to various medical applications. We also review and extend some of the existing results concerning β-transformations and (expanding) Lorenz mappings. Then we apply them for deducing important properties of spike-trains generated by the CNV model and explain their implications for neuron behaviour....
-
Dipolowy model pola elektrycznego okrętu
PublicationOkręt o kadłubie stalowym będący w wodzie morskiej wytwarza wokół siebie pole elektryczne. Źródłem tego pola są procesy elektrochemiczne i ochrona katodowa okrętu. Analiza pola elektrycznego wokół okrętu jest istotna z punktu widzenia identyfikacji oraz ochrony przeciwminowej. W pracy przedstawiono uproszczony model dipolowy pola magnetycznego okrętu, który pozwala na obliczenie rozkładu pola elektrycznego w tzw. strefie dalekiej...
-
Shading, Dusting and Incorrect Positioning of Photovoltaic Modules as Important Factors in Performance Reduction
PublicationThe amount of solar radiation reaching the front cover of a photovoltaic module is crucial for its performance. A number of factors must be taken into account at the design stage of the solar installation, which will ensure maximum utilization of the potential arising from the location. During the operation of a photovoltaic installation, it is necessary to limit the shading of the modules caused by both dust and shadowing by trees...
-
Reduction of spectral interferences in atmospheric pressure glow discharge optical emission spectrometry
Publication -
Critical study of crop-derived biochars for soil amendment and pharmaceutical ecotoxicity reduction
Publication