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Search results for: MULTI CONSTRAINED ROUTING
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Sensorless Control of Induction Machine Supplied by Current Source Inverter
PublicationThe paper describes the voltage control technique of induction machines supplied by a current source inverter. The control system is based on proposed new multi-scalar variables, which are named “r.” The control system contains the output filter capacitor's model. In the sensorless control system the Z type backstepping speed observer was applied. The mathematical dependences are confirmed by simulation and experimental research.
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Reliable renewable energy – application of electrochemical capacitors for electrical energy storage
PublicationThis paper presents electrical energy storage devices such as electrochemical capacitors, their principle of operation and electrode materials most commonly used in their manufacturing technology. Moreover, our research on development of new nanocomposite materials based on multi-walled carbon nanotubes and conducting polymer is shown. Additionally, the possibility and advantages of application of supercapacitors for accumulation...
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Impact of Urbanization on Stormwater Runoff from a Small Urban Catchment: Gdańsk Małomiejska Basin Case Study
PublicationThis paper deals with the impact of different forms of urbanization on the basin outflow. The influence of changes in land cover/use, drainage system development, reservoirs, and alternative ways of stormwater management (green roofs, permeable pavements) on basin runoff was presented in the case of a small urban basin in Gdańsk (Poland. Seven variants of area development (in the period of 2000-2012) – three historical and four...
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A repeated game formulation of network embedded coding for multicast resilience in extreme conditions
PublicationComputer networks and data sharing applications are vital for our current society and fundamental for any available ICT solution, so that networking is considered as one of the key critical infrastructures and its correct behavior should be always enforced, even in case of disasters or severe execution conditions. Resilience is a strongly demanding nonfunctional requirement for current computer networks, and one of the key factors...
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Reliable Surrogate Modeling of Antenna Input Characteristics by Means of Domain Confinement and Principal Components
PublicationA reliable design of contemporary antenna structures necessarily involves full-wave electromagnetic (EM) analysis which is the only tool capable of accounting, for example, for element coupling or the effects of connectors. As EM simulations tend to be CPU-intensive, surrogate modeling allows for relieving the computational overhead of design tasks that require numerous analyses, for example, parametric optimization or uncertainty...
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Reliable EM-driven size reduction of antenna structures by means of adaptive penalty factors
PublicationMiniaturization has become of paramount importance in the design of modern antenna systems. In particular, compact size is essential for emerging application areas such as internet of things, wearable and implantable devices, 5G technology, or medical imaging. On the other hand, reduction of physical dimensions generally has a detrimental effect on antenna performance. From the perspective of numerical optimization, miniaturization...
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Optimization-based antenna miniaturization using adaptively-adjusted penalty factors
PublicationThe continuing trend for miniaturization of electronic devices necessitates size reduction of the comprising components and circuitry. Specifically, integrated circuit-antenna modules therein require compact radiators in applications such as 5G communications, implantable and on-body devices, or internet of things (IoT). The conflict between the demands for compact size and elec-trical and field performance can be mitigated by...
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Cascaded Buck Hybrid Interlink Converter for Multiple-Input / Multiple-Output Operation
PublicationThe provision of isolated- and non-isolated DC output voltages by Power electronics power-conditioning devices in the recent ‘green-energy-revolution’ era is on course. In this paper, a structure for multi-input multi-output(MIMO) DC–DC buck converter is proposed to generate output voltages of varying levels with fewer component-count. The DC output voltage of each of the constituting buck converters can be used independently or...
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The need for new transport protocols on the INTERNET
PublicationThe TCP/IP protocol suite is widely used in IP networks, regardless of diverse environments and usage scenarios. Due to the fact of being the basic concept of organizing the work of the Internet, it is the subject of interest and constant analysis of operators, users, network researchers, and designers. The Internet is a "living" organism in which new needs appear all the time. This is particularly important due to the emerging...
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Compact antenna array comprising fractal-shaped microstripradiators
PublicationA design method of antenna array consisting of eight microstrip patches modified with Sierpinski fractal curves has been presented andexperimentally validated in this paper. Method proposed has enabled the achievement of considerable miniaturization of array length (26%),together with multi-band behavior of the antenna, which proves the attractiveness of presented design methodology and its ability to be implemented in more complex...
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Document Agents with the Intelligent Negotiations Capability
PublicationThe paper focus is on augmenting proactive document-agents with built -in intelligence to enable them to recognize execution context provided by devices visited durning the business process, and to reach collaboration agreement despite of their conflicting requirements. We propose a solution based on neural networks to improve simple multi-issue negotiation between the document and the device, practically with no excessive cost...
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DATABASE AND BIGDATA PROCESSING SYSTEM FOR ANALYSIS OF AIS MESSAGES IN THE NETBALTIC RESEARCH PROJECT
PublicationA specialized database and a software tool for graphical and numerical presentation of maritime measurement results has been designed and implemented as part of the research conducted under the netBaltic project (Internet over the Baltic Sea – the implementation of a multi-system, self-organizing broadband communications network over the sea for enhancing navigation safety through the development of e-navigation services.) The...
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Gains selection of non-proportional observers of an induction motor with dyadic methods
PublicationThe paper presents issues related to calculation of gains of non-proportional observers of magnetic fluxes of an induction motor. A transformation is discussed, based on dyadic matrices, that affords possibility of applying well-known methods used in single-output systems to observers of multi-output systems. The impact of dyadic transformation on possibility of poles placement of the observer is analyzed....
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Cheap Cancellation of Strong Echoes for Digital Passive and Noise Radars
PublicationThe problem of cancellation of strong, potentially nonstationary,echoes in noise radars and passive radars utilizing digitaltransmissions is considered. The proposed solution is a multi-stage procedure.Initial clutter estimates, obtained using the least mean squares(LMS) algorithm, are refined using specially designed filters, "matched"to spectral densities of targets and clutter. When the postprocessing filtersare noncausal, the...
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Implementation of high-speed data transmission technological demonstrator using software defined radio technology
PublicationIn the article implementation of a high-speed data transmission technological demonstrator using software defined radio technology is presented. A system architecture design including asymmetric framing transmission organization, which differs from the ones used in cellular systems is described. The construction of technological demonstrator consisting of a management unit, radio unit and programmable multi-threaded software performing...
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Optimal Multivariable Control for Modified Z-source Based IPT
PublicationThis paper describes Z-source based inductive power transfer topologies control approaches. The goal of this work is a multi-variable control approach which involves a constant voltage/constant current control along with an optimal frequency control to obtain maximum efficiency. This control is applied to the wireless power transfer system based on a modified Z-source topology. The description of the control method along with simulation...
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Increasing the Utilization of dc-link Voltage of a Five-Leg VSI Based on Rotor Angle Control of Dual Induction Motors
PublicationThis paper introduces an increased utilization of the dc-link voltage of a five-leg voltage source inverter (VSI) based on the rotor flux angle control technique for dual induction motors, IM. The main purpose is to utilize additional abilities provided by a multi-motor drive system in limited operating conditions. Generally, a multi-motor drive system is widely used in electric vehicles (EVs), traction systems and in several industrial...
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Nonlinear numerical simulation of earthquake-induced pounding between timber frame buildings
PublicationEarthquakes may induce serious dynamic loads acting on buildings, which can lead to damage or even destruction of the whole structure. In densely populated areas, it is quite common that buildings are located very close one to another which can result in pounding between them during ground motions. Due to the environmental awareness, multi-story timber frame buildings are gaining popularity and therefore there is a need to investigate...
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Simulation-Based Approach to a More Efficient Handling Strategy for a Container Terminal Storage Yard: Case Study of the Baltic Hub Container Terminal
PublicationThe primary objective of this research was to implement a more efficient handling strategy in the container terminal storage yard at the Baltic Hub Container Terminal (BHCT). Following an analysis of the current logistics system associated with starboard-side mooring, an attempt was made to shift the mooring to the port side. Two routing strategies corresponding to the analysed mooring operations were tested using a developed model....
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How Machine Learning Contributes to Solve Acoustical Problems
PublicationMachine learning is the process of learning functional relationships between measured signals (called percepts in the artificial intelligence literature) and some output of interest. In some cases, we wish to learn very specific relationships from signals such as identifying the language of a speaker (e.g. Zissman, 1996) which has direct applications such as in call center routing or performing a music information retrieval task...
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Hybrid approach to ontology specification and development
PublicationIn this chapter a first draft of a hybrid ontology development approach is presented. The context of this method encompasses the multi-agent system equipped with knowledge bases and inferring engine. The process of ontology engineering appears as a complex issue, as it addresses different point-views of both, a client and a modeler with a requirements/system analyst. Regarding this, an approach based on the knowledge preprocessing...
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Evolutionary Sets of Safe Ship Trajectories: the Method's Development and Selected Reaserch Results
PublicationThe Evolutionary Sets of Safe Ship Trajectories is a method solving ship encounter situations. The method combines evolutionary approach to planning ship trajectory with some of the assumption of game theory. For given positions and motion parameters the method finds a near optimal set of safe trajectories of all ships involved in an encounter. This paper presents framework of the method and its development. Additionally, selected...
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Environmental impact of construction. Methods of conscious shaping architecture in terms of ecological solutions
PublicationShaping an ecologically conscious society is a process that also affects architecture. Currently, designers are eagerly looking for solutions that are beneficial in terms of carbon footprint. For the proper multi-criteria assessment and selection of adequate solutions, it is necessary to use appropriate tools such as, for example, the Life Cycle Assessment (LCA) method or the rules of ecological certification (BREEAM and LEED)....
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UKŁADY KONSTRUKCYJNE LEKKIEJ OBUDOWY
PublicationW artykule przedstawiono rozwiązania konstrukcyjne przegród zewnętrznych lekkiej obudowy jednowarstwowych (nieizolowanych termicznie), wielowarstwowych (izolowanych termicznie) oraz szklano-metalowych. Omówiono procesy modyfikacji konstrukcji ścian. Podano przykładowe rozwiązania.
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Impact of the type of heat exchanger on the characteristics of low-temperature thermoacoustic heat engines
PublicationThermoacoustic technologies are considered an effective solution for harnessing low-temperature heat, whether from waste or renewable sources. However, in practice, developing and implementing high-performance ther- moacoustic systems is a complex challenge. In real waste heat recovery systems, heat exchange between ther- moacoustic engines (TAEs) and external heat sources is facilitated by auxiliary systems, such as circulation...
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The influence of a change in the meniscus cross-sectional shape on the medio-lateral translation of the knee joint and meniscal extrusion
PublicationObjective The purpose of this study was to evaluate the influence of a change in the meniscus cross sectional shape on its position and on the biomechanics of a knee joint. Methods One main finite element model of a left knee joint was created on the basis of MRI images. The model consisted of bones, articular cartilages, menisci and ligaments. Eight variants of this model with an increased or decreased meniscus height were then...
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Cost-Efficient Bi-Layer Modeling of Antenna Input Characteristics Using Gradient Kriging Surrogates
PublicationOver the recent years, surrogate modeling has been playing an increasing role in the design of antenna structures. The main incentive is to mitigate the issues related to high cost of electromagnetic (EM)-based procedures. Among the various techniques, approximation surrogates are the most popular ones due to their flexibility and easy access. Notwithstanding, data-driven modeling of antenna characteristics is associated with serious...
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Determination of stepped plate thickness distribution using guided waves and compressed sensing approach
PublicationGuided waves recently have attracted significant interest as a very promising research area. The signals registered by a specially designed sensor network are processed to assess the state of the tested structure. Despite the constant development of novel damage detection algorithms employing guided waves, the phenomenon of wave propagation still needs detailed recognizing and understanding for the further progress of non-destructive...
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Deep Learning Optimization for Edge Devices: Analysis of Training Quantization Parameters
PublicationThis paper focuses on convolution neural network quantization problem. The quantization has a distinct stage of data conversion from floating-point into integer-point numbers. In general, the process of quantization is associated with the reduction of the matrix dimension via limited precision of the numbers. However, the training and inference stages of deep learning neural network are limited by the space of the memory and a...
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Tomasz Zubowicz dr inż.
PeopleTomasz Zubowicz has received his M.Sc. Eng. degree in Control Engineering from the Faculty of Electrical and Control Engineering at the Gda{\'n}sk University of Technology (GUT) in $2008$. He received his Ph.D. Eng. (Hons.) in the field of Control Engineering from the same faculty in $2019$. In $2012$ he became a permanent staff member at the Department of Intelligent Control and Decision Support Systems at GUT and a member of...
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Ocena funkcjonowania klastrów przemysłowych
PublicationAutorzy artykułu w sposób kompleksowy opisali najbardziej popularne metody stosowane w badaniach struktur sieciowych typu klaster przemysłowy. Wśród opisanych metod znalazły się metody ilościowe (Input/Output, location quotient LQ, shift-share), jakościowe (m.in. opinie ekspertów, multi-sectoral qualitative analysis MSQA, przeglądy) oraz mieszane (m.in. analiza GEM, diagram pajęczynowy, szablon narodowy, analiza sieci współpracy).
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From Sequential to Parallel Implementation of NLP Using the Actor Model
PublicationThe article focuses on presenting methods allowing easy parallelization of an existing, sequential Natural Language Processing (NLP) application within a multi-core system. The actor-based solution implemented with the Akka framework has been applied and compared to an application based on Task Parallel Library (TPL) and to the original sequential application. Architectures, data and control flows are described along with execution...
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ALOFON corpus
Open Research DataThe ALOFON corpus is one of the multimodal database of word recordings in English, available at http://www.modality-corpus.org/. The ALOFON corpus is oriented towards the recording of the speech equivalence variants. For this purpose, a total of 7 people who are or speak English with native speaker fluency and a variety of Standard Southern British...
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Nowa metoda obliczania rozpływu prądów zwarciowych w przewodach odgromowych linii wysokiego napięcia
PublicationReferat przedstawia nowatorską metodę obliczania wartości prądów płynących w przewodach odgromowych w czasie zwarć, pozwalającą na dobór przewodów odgromowych pod względem wytrzymałości cieplnej. Proponowana metoda charakteryzuje się większą dokładnością i większą uniwersalnością niż powszechnie stosowane metody, pozwalając tym samym na dobór przewodów odgromowych z mniejszym ryzykiem niepewności. Prezentowana metoda obliczeniowa...
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A high-accuracy method of computation of x-ray waves propagation through an optical system consisting of many lenses
PublicationThe propagation of X-ray waves through an optical system consisting of many X-ray refractive lenses is considered. Two differential equations are contemplated for solving the problem for electromagnetic wave propagation: first – an equation for the electric field, second – an equation derived for a complex phase of an electric field. Both equations are solved by the use of a finite-difference method. The simulation error is estimated...
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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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Ireneusz Kreja dr hab. inż.
PeopleGraduated from the mathematical class at the Nicolaus Copernicus High School in Gdańsk (1974). Master of Sciences in Civil Engineering after studies at Gdansk University of Technology (GUT), Poland (1974-1979). Since 1979 became an employee of the GUT. In 1989 earned a Ph.D. degree in Civil Engineering (with grade "Summa cum Laude") from the GUT. In 2008 obtained a D. Sc. (Habilitation) degree in Civil Engineering (with grade...
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Surf Zone Currents in the Coastal Zone of the Southern Baltic Sea – a Modelling Approach
PublicationNearshore currents in a multi-bar non-tidal coastal zone environment located in the Southern Baltic Sea are studied. Spatiotemporal seaward-directed jets – so-called rip currents – are an important part of the nearshore current system. In previous research, Dudkowska et al. (2020) performed an extended modelling experiment to determine the wave conditions that are conducive to the emergence of rip currents. In this paper, the...
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Modulacja FMT: właściwości oraz efektywna realizacja modulatora z wykorzystaniem algorytmu overlap-add
PublicationW artykule omówiono koncepcję modulacji FMT (ang. Filtered Multi-Tone) z próbkowaniem krytycznym oraz niekrytycznym, a także porównano podstawowe właściwości sygnałów w ten sposób zmodulowanych. Szczegółowo omówiono efektywną implementację modulatora FMT z wykorzystaniem banku filtrów polifazowych oraz techniki overlap-add. Pokazano wpływ parametrów modulatora, w tym charakterystyk filtru oraz odstępów miedzy nośnymi na charakterystyki...
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O kształtowaniu stalowych, wieloprzęsłowych mostów drogowych
PublicationW referacie autor przedstawił główne trendy i swoje własne uwagi odnośnie koncepcyjnego projektowania wieloprzęsłowych mostów stalowych. Bazując na zakończonych projektach autor przedstawił teoretyczne i techniczne problemy które wystąpiły podczas projektowania bądź budowy wybranych obiektów mostowych.
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Modernizacja układów geometrycznych toru z wykorzystaniem metody oceny wielokryterialnej
PublicationW pracy przedstawiono główne założenia opracowanej metody wielokryterialnej oceny stosowanej przy przebudowie układów geometrycznych toru. Określono kryteria wpływające na inwestycje modernizacyjne. Zdefiniowano zastosowaną w analizie funkcję celu. Przedstawiono przykład zastosowania algorytmu optymalizacyjnego z wykorzystaniem programu komputerowego
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Validation of an Agent and Ontology-based Information Technology Assessment System
PublicationThe aim of this paper is to present a new method of the validation of an Agent and Ontology-based Information Technology Assessment System. In the introduction part of the paper, the characteristics of the proposed multi-agent system are presented. Next, some important details regarding the ontology functionality of this system are described and an approach to its verification process is proposed. The approach employs semantic...
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Analiza rozdrabniania mikroziaren ściernych w docieraniu powierzchni płaskich.
PublicationPrzedstawiono analizę porównawczą mikroziaren przed i po docieraniu. Badania przeprowadzono na skomputeryzowanym stanowisku do automatycznej analizy obrazu mikroskopowego wyposażonego w oprogramowanie Multi Scan. Docierano elementy stalowe w stanie miękkim i po ulepszeniu cieplnym o przekroju kołowym i trójkątnym. Stosowano mikroziarna elektrokorundu i węglika krzemu o różnej ziarnistości. Badano rozdrobnienie mikroziaren przy...
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The (Un)Real City by Magdalena Abakanowicz: Guidelines for Cities in Times of Planetary Crisis
PublicationThree decades have passed since Magdalena Abakanowicz presented her concept of Bois de Nanterre — Arboreal Architecture, in response to a call for a broader reflection on approaches to urban landscaping and a reinterpretation of the meaning and evolution of the Grand Axis in Paris. This paper analyses the work presented by the artist from an urban planning perspective. It shows how the rich and multi-layered metaphor for the 21st-century...
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An Analysis of Probe-Fed Rectangular Patch Antennas With Multilayer and Multipatch Configurations on Cylindrical Surfaces
PublicationA multi-patch configuration of probe-fed rectangular microstrip antennas mounted on a cylindrical body, with electrically small radius, with an arbitrary number of substrate and superstrate layers is investigated in this paper. A full-wave analysis and a moment-method calculation are employed. A unified procedure for creating proper matrices for the investigated geometry of the structure is outlined here. Numerical results for...
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AUTOMATED NEGOTIATIONS OVER COLLABORATION PROTOCOL AGREEMENTS
PublicationThe dissertation focuses on the augmentation of proactive document - agents with built-in intelligence to recognize execution context provided by devices visited during a business process, and to reach collaboration agreement despite conflicting requirements. The proposed solution, based on intelligent bargaining using neural networks to improve simple multi-issue negotiation between the document and thedevice, requires practically...
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Comparative Analysis of Salient and Non-Salient Pole Brushless Synchronous Generator for Application in Autonomous Electric Power System
PublicationThis paper presents a comparative study of two types of brushless synchronous generator for application in autonomous electric power systems (e.g. airplane power grid). Commercially used salient pole and a prototype non-salient pole high speed multi-pole brushless synchronous generator (BSG) have been presented. Comparative analysis of both types of the generator has been performed. Chosen simulation (using FEM and circuit models)...
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Application of Majority Voting Protocols to Supporting Trading Decisions
PublicationA broad spectrum of analysis and prediction indicators and methods exists to support trading decisions, but no hard knowledge exist to tell in advance which of them will fit best in a given timeframe. To support trading decisions, a multi-agent self-organizing system has been proposed. The system is based on history based dynamic weight voting and selects the right indicators based on their past performance. The formal analysis...
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APPLICATION OF MAJORITY VOTING PROTOCOLS TO SUPPORTING TRADING DECISIONS
PublicationA broad spectrum of analysis and prediction indicators and methods exists to support trading decisions, but no hard knowledge exist to tell in advance which of them will fit best in a given timeframe. To support trading decisions, a multi-agent self-organizing system has been proposed. The system is based on history based dynamic weight voting and selects the right indicators based on their past performance. The formal analysis...
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An Enhanced Reduced Basis Method for Wideband Finite Element Method Simulations
PublicationIn this paper, we present a novel strategy for selecting expansion points in the reduced basis method. A single computation of the error estimator is used to select a few expansion points in the multi-parameter space simultaneously. The number of selected points is determined adaptively, based on the accuracy of the current reduced model. The reliability and efficiency of this proposed approach are illustrated by numerical tests...