Filtry
wszystkich: 1567
-
Katalog
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: MULTI-CRITERION RATING
-
Porównanie algorytmów MGA i NGA do projektowania i optymlizacji kombinacyjnych układów cyfrowych z algorytmem MLCEA.
PublikacjaW artykule zaprezentowano porównanie algorytmów ewolucyjnych do projektowania i optymalizacji kombinacyjnych układów cyfrowych. Porównano algorytmy MGA (Multiobjective Genetic Algorithm) i NGA (Genetic Algorithm with N-cardinality Reprezentation) z utworzonym algorytmem MLCEA (Multi-Layer Chromosome Evolutionary Algorithm), bazującym na reprezentacji osobników w postaci chromosomów wielowarstwowych. Otrzymane wyniki dla algorytmu...
-
A Generative Approach to Hull Design for a Small Watercraft
PublikacjaIn the field of ocean engineering, the task of spatial hull modelling is one of the most complicated problems in ship design. This study presents a procedure applied as a generative approach to the design problems for the hull geometry of small vessels using elements of concurrent design with multi-criteria optimisation processes. Based upon widely available commercial software, an algorithm for the mathematical formulation of...
-
Benchmarking Parallel Chess Search in Stockfish on Intel Xeon and Intel Xeon Phi Processors
PublikacjaThe paper presents results from benchmarking the parallel multithreaded Stockfish chess engine on selected multi- and many-core processors. It is shown how the strength of play for an n-thread version compares to 1-thread version on both Intel Xeon and latest Intel Xeon Phi x200 processors. Results such as the number of wins, losses and draws are presented and how these change for growing numbers of threads. Impact of using particular...
-
Low harmonic multipulse voltage converters using coupled reactors
PublikacjaThis paper presents a novel approach to the multi pulse voltage converters (VC), especially voltage source inverters (VSI) and matrix converters (MC) based on several typical identical modules connected in parallel using coupled reactors. Such arrangements resulting in lower voltage distortions at extremely low switching frequency. The proposed arrangement was validated by simulation. Laboratory models of 18- and 24pulse 3-level...
-
Połączenie G3 dwóch kierunków prostych z użyciem krzywej NURBS
PublikacjaW artykule przedstawiono nową metodę projektowania układu geometrycznego toru kolejowego opartą na zastosowaniu krzywych NURBS (Non-Uniform Rational B-Spline) do opisu krzywizny. Punkty kontrolne krzywej NURBS wyznaczane są w procesie optymalizacji za pomocą algorytmu genetycznego. Jako kryterium optymalizacji przyjęto minimalizację oddziaływań dynamicznych występujących w układzie tor-pojazd przy spełnieniu warunków geometrycznych...
-
Projektowanie układów ramowych z zastosowaniem analizy wrażliwości
PublikacjaW pracy przedstawiono przykład projektowania układów ramowych z zastosowaniem analizy wrażliwości. Rozważane układy ramowe rozwiązano autorskim programem napisanym w środowisku MATLAB, metodą elementów skończonych. Badano wpływ zmiany modułu Younga oraz wpływ zmiany wielkości przekroju poprzecznego na wybrane przemieszczenia ramy. Przedstawiono wyniki dla analizy wrażliwości jedno i wieloparametrycznej.
-
Theory versus experiment for vacuum Rabi oscillations in lossy cavities
PublikacjaThe 1996 experiment by Brune et al. [Phys. Rev. Lett. 76, 1800 (1996)] on vacuum Rabi oscillation is analyzed by means of alternative models of atom-reservoir interaction. Agreement with experimental Rabi oscillation data can be obtained if one defines jump operators in the dressed-state basis and takes into account thermal fluctuations between dressed states belonging to the same manifold. Such low-frequency transitions could...
-
Quantitative assessment of the influence of tensile softening of concrete in beams under bending by numerical simulations with XFEM and cohesive cracks
PublikacjaResults of the numerical simulations of the size effect phenomenon for concrete in comparison with experimental data are presented. In-plane geometrically similar notched and unnotched beams under three-point bending are analyzed. EXtended Finite Element Method (XFEM) with a cohesive softening law is used. Comprehensive parametric study with the respect to the tensile strength and the initial fracture energy is performed. Sensitivity...
-
Cyclic behaviour modelling of additively manufactured Ti-6Al-4V lattice structures
PublikacjaThe present work is concerned with the numerical modelling of the cyclic behaviour of Ti-6Al-4V lattice structures. In the study, diamond structures of titanium alloy produced by the additive laser powder bed fusion (LPBF) method with different degrees of relative density were used. Realistic geometric models of the studied mesostructures were generated using computed microtomography, taking into account the imperfections of the...
-
On some problems in determining tensile parameters of concrete model from size effect tests
PublikacjaThe paper presents results of numerical simulations of size effect phenomenon in concrete specimens. The behaviour of in-plane geometrically similar notched and unnotched beams under three-point bending is investigated. In total 18 beams are analysed. Concrete beams of four different sizes and five different notch to depth ratios are simulated. Two methods are applied to describe cracks. First, an elasto-plastic constitutive law...
-
When all we have is not enough: a search for the optimal method of quantifying inflation expectations
PublikacjaAlthough inflation expectations are pivotal variables for central banks, they are not directly observable. Therefore, central banks use qualitative survey results to proxy consumer expectations, and their quantification in this manner is often criticized. In this study, we investigate and identify an optimal quantification procedure for survey results based on a set of regression and probabilistic models. Specifically, we seek...
-
A coupled constitutive model for fracture in plain concrete based on continuum theory with non-local softening and eXtended Finite Element Method
PublikacjaThe paper presents a constitutive model for concrete which combines a continuous and discontinuous fracture description. In a continuum regime, two different constitutive laws were used. First, a plasticity model with a Rankine failure criterion and an associated fl ow rule was used. Second, a constitutive law based on isotropic damage mechanics was formulated. In order to capture the width of a localized zone and to obtain mesh-independent...
-
Reliable computationally-efficient behavioral modeling of microwave passives using deep learning surrogates in confined domains
PublikacjaThe importance of surrogate modeling techniques has been steadily growing over the recent years in high-frequency electronics, including microwave engineering. Fast metamodels are employed to speedup design processes, especially those conducted at the level of full-wave electromagnetic (EM) simulations. The surrogates enable massive system evaluations at nearly EM accuracy and negligible costs, which is invaluable in parameter...
-
Smart Approach for Glioma Segmentation in Magnetic Resonance Imaging using Modified Convolutional Network Architecture (U-NET)
PublikacjaSegmentation of a brain tumor from magnetic resonance multimodal images is a challenging task in the field of medical imaging. The vast diversity in potential target regions, appearance and multifarious intensity threshold levels of various tumor types are few of the major factors that affect segmentation results. An accurate diagnosis and its treatment demand strict delineation of the tumor affected tissues. Herein, we focus on...
-
Testing the Effect of Bathymetric Data Reduction on the Shape of the Digital Bottom Model
PublikacjaDepth data and the digital bottom model created from it are very important in the inland and coastal water zones studies and research. The paper undertakes the subject of bathymetric data processing using reduction methods and examines the impact of data reduction according to the resulting representations of the bottom surface in the form of numerical bottom models. Data reduction is an approach that is meant to reduce the size...
-
Interdisciplinary research as a form of monument protection and preparation for the investment process on the example of the former Gdańsk Shipyard complex
PublikacjaThe multi-layered heritage of many industrial plants operating until the end of the 20th century creates a particular challenge for conservators, designers and investors. In the process of protecting its values, displaying qualities and managing the property, it is necessary to recognize a wider transformation of technology of the entire plant and the individual functions of its buildings, as well as the context of intangible...
-
Context-aware User Modelling and Generation of Recommendations in Recommender Systems
PublikacjaRecommender systems are software tools and techniques which aim at suggesting new items that may be of interest to a user. This dissertation is focused on four problems in recommender systems domain. The first one is context-awareness, i.e. how to obtain relevant contextual information, how to model user preferences in a context and use them to make predictions. The second one is multi-domain recommendation, which aim at suggesting...
-
Universal autonomous control and management system for multipurpose unmanned surface vessel
PublikacjaThe paper presents design, structure and architecture of the Universal Autonomous Control and Management System (UACAMS) for multipurpose unmanned surface vessel. The system was designed, installed and implemented on the multipurpose platform - unmanned surface vessel named HydroDron. The platform is designed to execute hydrographic survey missions with multi-variant configuration of the survey system (payload? ) including multi-beam...
-
Adaptive Positioning Systems Based on Multiple Wireless Interfaces for Industrial IoT in Harsh Manufacturing Environments
PublikacjaAs the industrial sector is becoming ever more flexible in order to improve productivity, legacy interfaces for industrial applications must evolve to enhance efficiency and must adapt to achieve higher elasticity and reliability in harsh manufacturing environments. The localization of machines, sensors and workers inside the industrial premises is one of such interfaces used by many applications. Current localization-based systems...
-
ZAAWANSOWANE SYMULACJE NUMERYCZNE MES DYNAMIKI MOSTÓW Z WYKORZYSTANIEM PROCEDURY EXPLICITE
PublikacjaDostęp do mocy obliczeniowej superkomputerów oraz możliwość wykorzystania nowoczesnych systemów, np. takich jak Ls-Dyna, pozwala na uzyskanie niezwykle szczegółowych rozwiązań bardzo skomplikowanych problemów inżynierskich. Zagadnienia te dotyczą zakresu statyki/stateczności jak i dynamiki dla rozbudowanych układów konstrukcyjnych zarówno w zakresie nieliniowości materiałowej jak i geometrycznej. Uzyskanie wiarygodnych wyników...
-
Ireneusz Kreja dr hab. inż.
OsobyAbsolwent klasy matematycznej I Liceum Ogólnokształcącego w Gdańsku im. Mikołaja Kopernika (1974). Absolwent Wydziału Budownictwa Lądowego Politechniki Gdańskiej (1979). Od 1979 pracuje na PG. W 1989 uzyskał doktorat (z wyróżnieniem), na Wydziale Budownictwa Lądowego, a w 2008 habilitował się (również z wyróżnieniem) na Wydziale Inżynierii Lądowej i Środowiska PG. Od 2011 jest profesorem PG. Na Politechnice Gdańskiej pełnił funkcje:...
-
Przygotowanie przemysłowego obiektu o stalowej konstrukcji nośnej do remontu po pożarze
PublikacjaW artykule przedstawiono warunki i sposób podejścia do naprawy stalowej konstrukcji nośnej kilkukondygnacyjnego obiektu przemysłowego, który uległ uszkodzeniu w wyniku oddziaływania wysokiej temperatury pożaru. Omówiono rodzaje badań i sprawdzeń oraz sposób przeprowadzenia kontroli konstrukcji, które stały się podstawą do wydania oceny technicznej o możliwości odbudowy i remontu obiektu, bez jego nadmiernej rozbiórki. Wskazany...
-
Elimination of impulsive disturbances from archive audio files – comparison of three noise pulse detection schemes
PublikacjaThe problem of elimination of impulsive disturbances (such as clicks, pops, ticks, crackles, and record scratches) from archive audio recordings is considered and solved using autoregressive modeling. Three classical noise pulse detection schemes are examined and compared: the approach based on open-loop multi-step-ahead signal prediction, the approach based on decision-feedback signal prediction, and the double threshold approach,...
-
Influence of nanoparticle concentration on thermal properties of thermal oil-MWCNT nanofluid
PublikacjaResults of the measurements of dynamic viscosity, thermal conductivity, electrical conductivity and pH of thermal oil-MWCNT (TO-MWCNT) nanofluid have been presented. Nanoparticles were tested at the concentration of 0.001%, 0.005%, 0.01%, 0.05%, and 0,1% by weight. Thermal oil (TO) was selected as a base liquid, because of possible application in ORC systems as an intermediate heating agent. Multi-walled carbon nanotubes were used...
-
Oznaczanie pozostałości pestycydów w próbkach żywności w wykorzystaniem metodyki QuEChERS = QuEChERS approach for the determination of pesticide residues in food matrixes
PublikacjaBez wątpienia, wartym uwagi podejściem do problemu oznaczania pestycydów, ze względu na różnorodność tej grupy związków, jest zastosowanie metodyk oznaczania pozostałości (multi-residue methods - MRMs). Niestety, w literaturze naukowej można znaleźć stosunkowo niewiele informacji na temat takiego podejścia do oznaczania pozostałości pestycydów w próbkach żywności. Stąd próba przybliżenia czytelnikom kilku najistotniejszych, zdaniem...
-
Selected Features of Dynamic Voting
PublikacjaIn multi-agent systems composed of autonomous agents with local knowledge, it is often desirable to aggregate their knowledge in order to make an educated decision. One of the methods of agreeing to a common decision is voting. A new history-based dynamic weight protocol allows for identification of the agents which contribute to the correct system decision. The main advantage of this approach, compared to static weighted system...
-
Performance Evaluation of the Parallel Codebook Algorithm for Background Subtraction in Video Stream
PublikacjaA background subtraction algorithm based on the codebook approach was implemented on a multi-core processor in a parallel form, using the OpenMP system. The aim of the experiments was to evaluate performance of the multithreaded algorithm in processing video streams recorded from monitoring cameras, depending on a number of computer cores used, method of task scheduling, image resolution and degree of image content variability....
-
Sensorless Disturbance Detection for Five Phase Induction Motor with Third Harmonic Injection
PublikacjaThe paper presents a sensorless disturbance detection procedure that was done on a five phase induction motor with third harmonic injection. A test bench was developed where a three phase machine serves as disturbance generator of different frequencies. The control of the machines is based on multi scalar variables that ensures an independent control of the motor EMF and the rotor flux. For disturbance identification a speed observer...
-
Synthesisand cytotoxic activity of conjugates of muramyl and normuramyl dipeptides with batracylin derivatives
PublikacjaOpisano syntezę analogów MDP oraz nor-MDP modyfikowanych w części peptydowej batracyliną i pochodnymi batracyliny. Opracowano udoskonaloną metodę syntezy batracyliny. Zaproponowana metoda pozwala na otrzymanie BAT w skali multi-gramowej. Zsyntetyzowane analogi nie wykazały aktywności cytotoksycznej w badaniach prowadzonych w NCI (Bethesda, USA). W testach in vitro przeprowadzonych w Akademii Medycznej w Gdańsku dwa analogi redukowały...
-
Special forms of echo visual representation in an ahead looking sonar.
PublikacjaThe paper discusses ways to organise visual representation in a multi-beam ahead looking sonars whose function is to detect objects on the bottom and in pelagic zones. Forms of visual representation are shown and illustrated on the basic screen (panoramic representation and setting, alarms) and on the auxiliary screen (type A, B and special). Special forms of visual representation are mainly used in detecting objects in difficult...
-
Moduł platformy SyMEC odpowiedzialny za współpracę serwera MEC z sieciami komórkowymi i bezprzewodowymi sieciami dostępowymi WLAN
PublikacjaZaprezentowano moduł współpracy z sieciami dostępowymi, będący istotnym elementem serwera MEC (Multi-access Edge Computing), budowanego w ramach projektu SyMEC i umożliwiającego uruchamianie elementów aplikacyjnych na brzegu sieci. Przedstawiono różnice w wymaganiach dotyczących sposobu realizacji tego komponentu w przypadku sieci dostępowych standaryzowanych przez 3GPP oraz sieci WLAN. Zaproponowana została architektura umożliwiająca...
-
Evidence-Based Risk Management for Civil Engineering Projects Using Bayesian Belief Networks (BBN)
PublikacjaThe authors are seeking new methods for improving the efficiency of the investments associated with the maintenance and operation of existing civil engineering structures. It is demonstrated how the knowledge about the elements of construction and operation phases and their relationships, combined with monitoring data can be used for more effective management of the risks associated with civil engineering projects. The methodology...
-
A Model for Risk Assessment and Management of Construction Projects in Urban Conditions
PublikacjaThe authors are seeking new methods for improving the efficiency of the investments associated with the maintenance and operation of existing civil engineering structures. It is demonstrated how the knowledge about the elements of construction and operation phases and their relationships, combined with monitoring data can be used for more effective management of the risks associated with civil engineering projects. The methodology...
-
Modelowanie bezpiecznika rozłącznikowego w układach formowania impulsów wielkiej mocy
PublikacjaProblem modelowania bezpieczników o dużej dynamice wyłączania prądu jest zagadnieniem szeroko opisywanym w literaturze. Układy takie mogą być wykorzystane w szczególności do formowania impulsów wysokiego napięcia o wartościach rzędu setek kV, charakteryzujących się czasem trwania rzędu ułamka μs. W niniejszej pracy przedstawiono empiryczny model bezpiecznika wielotopikowego, rozszerzony w oparciu o wyniki badań eksperymentalnych.
-
Modele numeryczne uwzględniające tarczową pracę pokrycia dachowego z blach trapezowych
PublikacjaW artykule porównano wybrane sposoby uwzględniania w modelowaniu numerycznym tarczowej pracy pokrycia dachowego z blachy trapezowej, możliwe do zrealizowania w programie Autodesk Robot Structural Analysis Professional 2015, w celu oceny słuszności stosowania ich do obliczeń konstrukcji nośnej współpracującej z poszyciem z blachy trapezowej. Analizy przeprowadzono dla pojedynczej przepony. Za pomocą powłokowych elementów skończonych...
-
Mapping of Flood-Prone Areas Utilizing GIS Techniques and Remote Sensing: A Case Study of Duhok, Kurdistan Region of Iraq
PublikacjaOne of the most common types of natural disaster, floods can happen anywhere on Earth, except in the polar regions. The severity of the damage caused by flooding can be reduced by putting proper management and protocols into place. Using remote sensing and a geospatial methodology, this study attempts to identify flood-vulnerable areas of the central district of Duhok, Iraq. The analytical hierarchy process (AHP) technique was...
-
Scheduling with Complete Multipartite Incompatibility Graph on Parallel Machines
PublikacjaIn this paper we consider a problem of job scheduling on parallel machines with a presence of incompatibilities between jobs. The incompatibility relation can be modeled as a complete multipartite graph in which each edge denotes a pair of jobs that cannot be scheduled on the same machine. Our research stems from the works of Bodlaender, Jansen, and Woeginger (1994) and Bodlaender and Jansen (1993). In particular, we pursue the...
-
Cutting model parameters from frame sawing of natural and impregnated Scots pine (Pinus sylvestris L.)
PublikacjaIn this paper, absolute and density normalized cutting model parameters of natural and impregnated Scots pine (Pinus sylvestris L.) are shown and a method for the calculation of their corresponding material properties in the principal material directions of wood is presented. The parameters were determined from measurements of cutting power on a sash gang saw, and are in detail the fracture toughness and the shear yield strength...
-
Analysis of circular polarization antenna design trade‐offs using low‐cost EM‐driven multiobjective optimization
PublikacjaCircular polarization (CP) antennas are vital components of modern communication systems. Their design involves handling several requirements such as low reflection and axial ratio (AR) within the frequency range of interest. Small size is an important criterion for antenna mobility which is normally achieved as a by‐product of performance‐oriented modifications of the structure topology. In this work, multiobjective optimization...
-
Frequency Response Functions for Sandvik CoroBore 825 XL boring tool, 733 mm
Dane BadawczeFrequency Response Functions (FRF) obtained for Sandvik CoroBore® 825 XL mounted at WHN 13-15 TOS VARNSDORF CNC machine at the minimum extension of the spindle adaptor. Tool set to bore a hole with a diameter 733mm
-
GPU based implementation of Temperature-Vegetation Dryness Index for AVHRR3 Satellite Data
PublikacjaPaper presents an implementation of TVDI (Temperature-Vegetation-Dryness Index) algorithm on GPU (Graphics Processing Unit). Calculation of this index is based on LST (Land Surface Temperature) and NDVI (Normalized Difference Vegetation Index). Discussed results are based on multi-spectral imagery retrieved from AVHRR3 sensors for area of Poland. All phases of TVDI implementation on GPU are modified in respect to CUDA platform....
-
DS-CDMA receiver in Software Defined Radio technology. Admission to the implementation of a RAKE receiver
PublikacjaProgrammable radio is one of the latest trends in the construction of multi-standard receivers. The technology, called Software Defined Radio (SDR), is also an ideal test platform that allows to try out different algorithms of signal receiving. This particular feature led to choose this platform to implement a DS-CDMA receiver (Direct Sequence Code Division Multiple Access). The use of SDR allows for a gradual upgrade of data processing...
-
Badanie jakości transmisji w interfejsie radiowym MC-CDMA
PublikacjaTechnika MC-CDMA (ang. Multi-Carrier Code Division Multiple Access) powstała z połączenia dwóch wcześniej stosowanych technik dostępu radiowego: CDMA (ang. Code Division Multiple Access) i OFDM (ang. Orthogonal Frequency-Division Multiplexing) i posiada zalety obu tych technologii. W referacie przedstawiona została budowa nadajnika i odbiornika dla tego interfejsu radiowego oraz wyniki badań symulacyjnych jakości transmisji w tym...
-
Performance Evaluation of Control Plane Functions in ASON/GMPLS Architecture
PublikacjaIt is assumed that demands of information society could be satisfied by architecture ASON/GMPLS comprehended as Automatically Switched Optical Network (ASON) with Generalized Multi-Protocol Label Switching (GMPLS) protocols. Introduction this solution must be preceded performance evaluation to guarantee society expectations. Practical realization is expensive and simulations models are necessary to examine standardized propositions....
-
Scalable Maintenance of Address Mapping and Autodetecion in Environments Where Agents are Uncapable of Self-Registration
PublikacjaWhen working with multi-agent systems it is often desirable to manage the agent set. The existing methods of central monitoring stems from two different fields of application. The first has its roots in in computer network monitoring, the other in mutli-agent simulation environments. Both approaches are not general enough to cater for loosely controlled environments, where the total agent population is not known and often fluctuating,...
-
Software tool for modelling of mechatronic systems with elastic continua
PublikacjaThe paper presents a systematic computational package for modelling and analysis of complex systems composed of multiple lumped and distributed parameter subsystems. The constructed computer program enables the frequency domain analysis of a class of linear systems and to obtain reduced order model in the form of bond graph. Obtained modal bond graph can be directly exported into 20-Sim package to further processing including nonlinear...
-
Finite element matrix generation on a GPU
PublikacjaThis paper presents an efficient technique for fast generation of sparse systems of linear equations arising in computational electromagnetics in a finite element method using higher order elements. The proposed approach employs a graphics processing unit (GPU) for both numerical integration and matrix assembly. The performance results obtained on a test platform consisting of a Fermi GPU (1x Tesla C2075) and a CPU (2x twelve-core...
-
Knowledge-Grid Modelling for Academic Purposes
PublikacjaNowadays, we face a huge amount of data and information sharing on the Web by different users worldwide. A multidimensional perspective in describing a university ontology seems to be very important for the modelling of higher education resources. This paper proposes a multi-dimensional knowledge model, designed to distribute and manage knowledge resources efficiently. We propose our model as the foundation of an advanced knowledge...
-
Vocalic Segments Classification Assisted by Mouth Motion Capture
PublikacjaVisual features convey important information for automatic speech recognition (ASR), especially in noisy environment. The purpose of this study is to evaluate to what extent visual data (i.e. lip reading) can enhance recognition accuracy in the multi-modal approach. For that purpose motion capture markers were placed on speakers' faces to obtain lips tracking data during speaking. Different parameterizations strategies were tested...
-
Elastoplastic nonlinear FEM analysis of FGM shells of Cosserat type
PublikacjaThe paper is a continuation of [1] where the formulation of the elastic constitutive law for functionally graded materials (FGM) on the grounds of nonlinear 6-parameter shell theory with the 6th parameter (the drilling degree of freedom) was presented. Here the formulation is extended to the elasto-plastic range. The material law is based on Cosserat plasticity and employs the well-known Tamura-Tomota-Ozawa (TTO) [2] mixture...