Search results for: distributed system
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On the complexity of distributed greedy coloring
PublicationW pracy rozważono problem kolorowania grafów przy dodatkowym założeniu, że kolor żadnego wierzchołka nie może zostać zmniejszony bez zmiany kolorów przynajmniej jednego z jego sąsiadów. Przeprowadzone rozważania dotyczyły złożoności obiczeniowej problemu w modelu Liniala obliczeń rozproszonych. Podano ograniczenia dolne i górne złożoności problemu oraz zestawiono problem z innymi pokrewnymi zagadnieniami grafowymi.
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Distributed Learning with Data Reduction
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The methods of secure data transmission in the KNX system
PublicationThe article presents the demands concerning data security in distributed building automation systems and shows the need for providing mechanisms of secure communication in the KNX system. Three different methods developed for KNX data protection are discussed: EIBsec, KNX Data Security and the author's method. Their properties are compared and potential areas of application are presented.
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Conception of interactive information and decision support system - model and evaluation
PublicationThis article presents conception of interactive information and decision support system for urban and industrial air quality management. The emphasis of the project is on real-time analysis and multi-media information, and support of distributed and mobile clients through the Internet.
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Distributed graph searching with a sense of direction
PublicationIn this work we consider the edge searching problem for vertex-weighted graphs with arbitrarily fast and invisible fugitive. The weight function w provides for each vertex v the minimum number of searchers required to guard v, i.e., the fugitive may not pass through v without being detected only if at least w(v) searchers are present at v. This problem is a generalization of the classical edge searching problem, in which one has...
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Geometric Algebra Model of Distributed Representations
PublicationFormalism based on GA is an alternative to distributed representation models developed so far-Smolensky's tensor product, Holographic Reduced Representations (HRR) and Binary Spatter Code (BSC). Convolutions are replaced by geometric products, interpretable in terms of geometry which seems to be the most natural language for visualization of higher concepts. This paper recalls the main ideas behind the GA model and investigates...
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Distributed Evacuation in Graphs with Multiple Exits
PublicationWe consider the problem of efficient evacuation using multiple exits. We formulate this problem as a discrete problem on graphs where mobile agents located in distinct nodes of a given graph must quickly reach one of multiple possible exit nodes, while avoiding congestion and bottlenecks. Each node of the graph has the capacity of holding at most one agent at each time step. Thus, the agents must choose their movements strategy...
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Data Partitioning and Task Management in the Clustered Server Layer of the Volunteer-based Computation System
PublicationWhile the typical volunteer-based distributed computing system focus on the computing performance, the Comcute system was designed especially to keep alive in the emergency situations. This means that designers had to take into account not only performance, but the safety of calculations as well. Quadruple-layered architecture was proposed to separate the untrusted components from the core of the system. The main layer (W) consists...
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Reliability data safety instrumented systems SIS from the functional safety analysis example critical instalation
Open Research DataThe dataset represents the results of an example of functional safety analysis systems is presented below. It is based on a control system, which consists of some basic components like sensors, programmable logic controllers and valves. It is a part of petrochemical critical installations. The communication between sensor logic controllers and actuators...
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Interactive information and decision support system for urban and industrial air quality management based on multi-agent system
PublicationThis article presents conception of interactive information and decision support system for urban and industrial air quality management. The emphasis of the project is on real-time analysis and multi-media information, and the support of distributed and mobile clients through the Internet. The approach integrates meteorological data and forecasts, air quality and emission monitoring, dynamic 3D simulation modelling and forecasting,...
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A consensus-based approach to the distributed learning
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Prototype selection algorithms for distributed learning
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An agent-based framework for distributed learning
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Distributed processing in medical, parametric imaging
PublicationArtykuł prezentuje metodę dystrybucji bazującej na JavaSpace do zastosowania w wyznaczaniu obrazów parametrycznych. Zaimplementowano metodologię Compute Server, którą użyto do aktywnej termografii i dynamicznych badań MRI mózgu.
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On greedy graph coloring in the distributed model
PublicationArtykuł traktuje o zachłannym kolorowaniu grafów w modelu rozproszonym. Zaprezentowano nowy probabilistyczny algorytm dający w wyniku pokolorowanie LF. Udowodniono, że jakakolwiek rozproszona implementacja LF wymaga co najmniej D rund, gdzie D jest maksymalnym stopniem wierzchołka w grafie.
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The methods of design reliable distributed networks
PublicationOpisano dwie metody projektowania niezawodnych sieci rozległych. W pierwszej metodzie przyjęto, że koszt konstrukcji każdego połączenia jest jednakowy, w drugiej koszty opisuje zadana macierz kosztów. Jako parametr niezawodnościowy przyjęto liczbę niezależnych dróg pomiędzy węzłami sieci. Pierwsza z metod jest metodą dokładną, druga heurystyczną. Zdefiniowano i oceniono błąd metody heurystycznej. Opublikowano wyniki otrzymane...
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Influence of Exception Handling on Distributed Applications.
PublicationW artykule przedstawiono metodologię oceny systemów rozproszonych w sytuacji występowania wyjątków i błędów. Analiza jest przeprowadzana przez zidentyfikowanie zmian stanów danych i wyprowadzenie ogólnych charakterystyk systemu. Rozproszone zależności są modelowane przez podstawowe zależności między metodami i złożone zależności występujące w sytemie. Analiza umożliwia odpowiedź na pytanie, jak zależności rozproszone wpływają na...
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Distributed wireless sensor for measuring humidity and temperature
PublicationHumidity and temperature monitoring is often required in industrial halls and laboratories and can be crucial, because many properties of electrical devices deteriorates under influence of these parameters. There are several useful commercial methods for measuring humidity and temperature, such as commercial hygrometers and humidity recorders. However, they do not allow data acquisition simultaneously from multiple sensors. This...
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A DISCRETE-CONTINUOUS METHOD OF MECHANICAL SYSTEM MODELLING
PublicationThe paper describes a discrete-continuous method of dynamic system modelling. The presented approach is hybrid in its nature, as it combines the advantages of spatial discretization methods with those of continuous system modelling methods. In the proposed method, a three-dimensional system is discretised in two directions only, with the third direction remaining continuous. The thus obtained discrete-continuous model is described...
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Towards Resource Theory of Coherence in Distributed Scenarios
PublicationThe search for a simple description of fundamental physical processes is an important part of quantum theory. One example for such an abstraction can be found in the distance lab paradigm: if two separated parties are connected via a classical channel, it is notoriously difficult to characterize all possible operations these parties can perform. This class of operations is widely known as local operations and classical communication....
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Distributed Detection of Selected Features in Data Streams Using Grid-class Systems
PublicationThis chapter describes basic methodology of distributed digital signal processing. A choice of distributed methods of detection of selected features in data streams using grid-class systems is discussed. Problems related to distribution of data for processing are addressed. A mitigating method for data distribution and result merging is described.
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Tracing of dynamic objects in distributed interactive simulation systems
PublicationDistributed interactive simulation systems require integration of several areas of computer science and applied mathematics to enable each individual simulation object to visualize effectively dynamic states of other objects. Objects are unpredictable,i.e., controlled by their local operators, and are remote, i.e., must rely on some transmission media to visualize dynamic scene from their local perspectives. The paper...
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Microgrid Energy Management System
PublicationIn the era of rapid development of "green energy” and storage devices, microgrids implemented in line with the concept of distributed generation can be an effective form of power management. There is a need for an efficient, optimal and reliable control of the combined infrastructure. The article presents a flexible, configurable microgrid's resources control system, which executes the task of meeting the electricity demand of...
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CMMI - an Assurance of Transferability of Knowledge andProjects in a Distributed Enterprise
PublicationCMMI (Capability Maturity Model Integrated)is a reference model fordefining and performing processes in software and systems engineeringorganizations.An organization implementing CMMI,among other things,assures thatacit knowledge is properly externalized into formal knowledge.This externalization gives an organization opportunity to assure that knowledge and development projects are easily transferable across adistributed enterprise...
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Possible uses of crisis situation aiding system in virtual world simulation
PublicationMany of the real world crisis situations like spreading fire, hostile units attack, flood, and etc. are commonly used in computer games where a simulation of extensive virtual world is crucial. This paper presents some ideas for possible uses of existing crisis situation aiding system in such environments. Moreover, it shows how this kind of system can be taught during subsequent games with a large number of players. As an example...
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Advanced surveillance and operational communication system employing mobile terminals
PublicationDistributed surveillance and operational communications system based on XMPP protocol is presented. Its architecture and assumptions leading to the depicted design are shown. Features of XMPP protocol are portrayed with the emphasis on those most important in the context of the application. Real-time multimedia transmission with the use of Jingle/XMPP extension is discussed. The use of PDA-class computers as mobile terminals is...
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Distributed Evolutionary Algorithm for Path Planning in Navigation Situation
PublicationThis article presents the use of a multi-population distributed evolutionary algorithm for path planning in navigation situation. The algorithm used is with partially exchanged population and migration between independently evolving populations. In this paper a comparison between a multi-population and a classic single-population algorithm takes place. The impact on the ultimate solution has been researched. It was shown that using...
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Ancillary services to grids provided with distributed generation
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A better practical algorithm for distributed graph coloring
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Distributed Data Reduction through Agent Collaboration
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Parallel processing subsystems with redundancy in a distributed environment
PublicationW pracy rozważano problem podziału systemu rozproszonego na spójne podsystemy złożone z przynajmniej trzech jednostek, pozwalające na detekcję i skorygowanie pojedynczych błędów. Wykazano, że problem maksymalizacji liczby takich jednostek jest NP-trudny nawet dla dwuspójnych kubicznych topologii sieci. Podano też nowe algorytmy przybliżone.
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Managing distributed architecture with Extendet WS-CDl
PublicationZaprezentowano problem wykorzystania języka WSCDL w warstwie zarzadzania usługami w architekturze systemu rozproszonego. Zaproponowano rozszerzenie modelu CDLExt uwzględniając istotne charakterystyki usług. Skoncentrowano się na zależności między usługami a innymi artyfaktami IT oraz określono atrybuty QoS wynikajace z tych zależności. Zaprezentowano implementację tego modelu oraz dalsze kierunki rozwoju CDLExt.
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RESTful atomic services for distributed digital libraries
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A distributed scheme for inter-domain routing optimization
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Real terrain visualisation with a distributed PC-cluster
PublicationJednym z zadań aplikacyjnych ogólnopolskiego projektu CLUSTERIX było opracowanie i wdrożenie metody interaktywnej wizualizacji terenu rzeczywistego z danych przestrzennych systemów GIS. Przedstawione wyniki osiągnięte w tym zadaniu wskazują na duży potencjał wykorzystania opracowanego modelu wizualizacji 3D dla potrzeb systemów zarządzania kryzysowego.
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Stepwise development of distributed interactive simulation systems.
PublicationMetoda krokowa pozwala na budowanie wydajnych i skalowalnych systemów symu-lacji rozproszonej obiektów rzeczywistych jak np. pojazdy terenowe, samocho-dy i śmigłowce. Dzięki uwzględnianiu parametrów operacyjnych oraz parametrównarzędzi wizualizacyjnych możliwe jest znaczne ograniczenie liczby komunika-tów przesyłanych między obiektami.
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Local information as a resource in distributed quantum systems.
PublicationZaproponowano nowy paradygmat dla kwantowego paradygmatu odległych laboratoriów w których informacja jest zasobem. W tym schemacie obserwatorzy dokonują destylacji informacji lokalnych stanów czystych.
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Distributed largest-first algorithm for graph coloring.
PublicationW artykule zaprezentowano rozproszony, probabilistyczny algorytm kolorowania grafów. Kolorowanie uzyskane jest optymalne lub prawie optymalne dla takich klas grafów jak koła dwudzielne, gąsienice czy korony. Udowodniono, że algorytm ten działa w czasie O(D^2 log n) rund dla dowolnego grafu n wierzchołkowegoo stopniu maksymalnym D.
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An experimental study of distributed algorithms for graph coloring.
PublicationW pracy podano algorytm rozproszonego kolorowania grafówi porównano ze znanym wcześniej algorytmem.
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Hunting for bindings in distributed object-oriented systems.
PublicationArtykuł dotyczy problemu identyfikacji grupy obiektów, które pozostają z danym obiektem w pewnej relacji. Problem ten jest szczególnie istotny w sytuacji, gdy należy wyodrębnić grupę obiektów w celu np. testowania czy monitorowania. W arykule zdefiniowano statyczną i dynamiczną relację powiązania pomiędzy obiektami w rozproszonym systemie obiektowym. Zaproponowano również architekturę umożliwiającą wyszukiwanie tych powiązań. Przedstawiono...
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A multi-agent method for periodicity detection in distributed events
PublicationMulti-agent systems working in constantly changing environments may be challenged by instantaneous unavailability of their autonomous agents caused e.g. by limited computing resources. A new method of self-organization of distributed service components is proposed, suitable for multi-agent systems. This method relies on particular agents carrying out separate analyzes of their individual processing loads or other specific events....
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Distributed Representations Based on Geometric Algebra: the Continuous Model
PublicationAuthors revise the concept of a distributed representation of data as well as two previously developed models: Holographic Reduced Representation (HRR) and Binary Spatter Codes (BSC). A Geometric Analogue (GAc - ''c'' stands for continuous as opposed to its discrete version) of HRR is introduced - it employs role-filler binding based on geometric products. Atomic objects are real-valued vectors in n-dimensional Euclidean space...
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Cartographic Representation of Route Reconstruction Results in Video Surveillance System
PublicationThe video streams available in a surveillance system distributed on the wide area may be accompanied by metadata are obtained as a result of video processing. Many algorithms applied to surveillance systems, e.g. event detection or object tracking, are strictly connected with localization of the object and reconstruction of its route. Drawing related information on a plan of a building or on a map of the city can facilitate the...
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Improving flexibility and performance of PVM applications by distributed partial evaluation
PublicationA new framework for developing both flexible and efficient PVM applications is described. We propose Architecture Templates Interface (ATI) that allows to control application granularity and parallelism. To ensure high application efficiency we extend partial evaluation strategy into domain of distributed applications obtaining Distributed Partial Evaluation (DPE). Both ATI and DPE were implemented using a new distributed programming...
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Distributed state estimation using a network of asynchronous processing nodes
PublicationWe consider the problem of distributed state estimation of continuous-time stochastic processes using a~network of processing nodes. Each node performs measurement and estimation using the Kalman filtering technique, communicates its results to other nodes in the network, and utilizes similar results from the other nodes in its own computations. We assume that the connection graph of the network is not complete, i.e. not all nodes...
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Distributed state estimation using a network of asynchronous processing nodes
PublicationWe consider the problem of distributed state estimation of continuous-time stochastic processes using a~network of processing nodes. Each node performs measurement and estimation using the Kalman filtering technique, communicates its results to other nodes in the network, and utilizes similar results from the other nodes in its own computations. We assume that the connection graph of the network is not complete, i.e. not all nodes...
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An application of multi-agent system for ship’s power systems design
PublicationDesign process of transport ship power system consists of structure (topology) and component elements selection. Compliance with the requirements for static components does not guarantee optimal dynamic characteristics of entire power system. Design steps are difficult to formalize and as a consequence to this reason expert and multi-agent systems are used for solving selected design issues. In the paper distributed multi-agent...
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Computational algorithm for the analysis of mechatronic systems with distributed parameter elements
PublicationThe paper presents a systematic computational package for analysis of complex systems composed of multiple lumped and distributed parameter subsystems. The algorithm is based on the transfer function method (DTFM). With this algorithm, a bond graph technique for the modelling is developed to simplify computations. Analysis of different systems requires only changing the inputs data in the form of the bond graph diagram
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Waldemar Korłub dr inż.
PeopleWaldemar Korłub obtained an Eng. degree in 2011, MSc.Eng. degree in 2012 and PhD in Computer Science in 2017 granted by the Faculty of Electronics, Telecommunications and Informatics at Gdansk University of Technology. His research interests include: distributed systems mainly grid and cloud computing platforms, autonomous systems capable of self-optimization, self-management, self-healing and self-protection, artificial intelligence...
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Integration of cloud-based services into distributed workflow systems: challenges and solutions
PublicationThe paper introduces the challenges in modern workflow management in distributed environments spanning multiplecluster, grid and cloud systems. Recent developments in cloud computing infrastructures are presented and are referring howclouds can be incorporated into distributed workflow management, aside from local and grid systems considered so far. Severalchallenges concerning workflow definition, optimisation and execution are...