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Search results for: POWER NETWORKS
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The searchlight problem for road networks
PublicationWe consider the problem of searching for a mobile intruder hiding in a road network given as the union of two or more lines, or two or more line segments, in the plane. Some of the intersections of the road network are occupied by stationary guards equipped with a number of searchlights, each of which can emit a single ray of light in any direction along the lines (or line segments) it is on. The goal is to detect the intruder,...
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Design and modeling of reliable networks
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Protection in elastic optical networks
PublicationIn this article, we analyze gains resulting from the use of EON architectures with special focus on transportation of cloud-ready and content-oriented traffic in the context of network resilience. EONs are a promising approach for future optical transport networks and, apart from improving the network spectral efficiency, bring such new capabilities as squeezed protection, which reduces resource requirements in failure scenarios....
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Resilient Routing in Communication Networks
PublicationThis important text/reference addresses the latest issues in end-to-end resilient routing in communication networks. The work highlights the main causes of failures of network nodes and links, and presents an overview of resilient routing mechanisms, covering issues related to the Future Internet (FI), wireless mesh networks (WMNs), and vehicular ad-hoc networks (VANETs). For each of these network architectures, a selection of...
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Multistage optical switching networks
PublicationEwolucja sieci szkieletowej w kierunku sieci DWDM o dużych szybkościach generuje nowe problemy dla kontynuacji. Ten element funkcjonalny musi także być oparty na technologii optycznej. Dla dużych pojemności nie może on być zrealizowany jako pojedynczy komutator, lecz jako wielosekcyjne pole komutacyjne. W artykule opisano trzy typy komutatorów: komutator światłowodów(FX), komutator długości fal (WSX) i komutator z konwersją długości...
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Survivability issues in multilayer networks
PublicationW artykule rozważa się zagadnienia zabezpieczenia i odtwarzania w wielowarstwowych architekturach sieciowych w celu osiągnięcia określonego poziomu przeżywalności po awarii węzła lub łącza. Problem optymalizacji polega na znalezieniu dla każdej optycznej ścieżki aktywnej, przenoszącej dany strumień IP, węzłowo-rozłącznej optycznej ścieżki zabezpieczającej w taki sposób, by awaria pojedyńczego węzła lub łącza spowodowana atakiem...
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Neural networks and deep learning
PublicationIn this chapter we will provide the general and fundamental background related to Neural Networks and Deep Learning techniques. Specifically, we divide the fundamentals of deep learning in three parts, the first one introduces Deep Feed Forward Networks and the main training algorithms in the context of optimization. The second part covers Convolutional Neural Networks (CNN) and discusses their main advantages and shortcomings...
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Voltage variations and their reduction in a rural low-voltage network with PV sources of energy
PublicationRenewable sources of energy (RES), especially photovoltaic (PV) micro-sources, are very popular in many countries. This way of clean power production is applied on a wide scale in Poland as well. The Polish legal regulations and tariffs specify that every prosumer in a low-voltage network may feed this network with a power not higher than the maximum declared consumed power. In power networks with RES, the voltage level changes...
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Fault detection in measuring systems of power plants
PublicationThis paper describes possibility of forming diagnostic relations based on application of the artifical neural networks (ANNs), intended for the identifying of degradation of measuring instruments used in developed power systems. As an example a steam turbine high-power plant was used. And, simulative calculations were applied to forming diagnostic neural relations. Both degradation of the measuring instruments and simultaneously...
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Optimization of Division and Reconfiguration Locations of the Medium-Voltage Power Grid Based on Forecasting the Level of Load and Generation from Renewable Energy Sources
PublicationThe article addresses challenges in optimizing the operation of medium voltage networks, emphasizing optimizing network division points and selecting the best network configuration for minimizing power and energy losses. It critically reviews recent research on the issue of network configuration optimization. The optimization of the medium voltage power grid reconfiguration process was carried out using known optimization tools....
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Neural Networks and the Evolution of Environmental Change
PublicationZmiany środowiskowe na Ziemii są odwieczne i liczą około 4 miliardy lat. Homo sapiens wpłynął na każdy aspekt środowiska ziemskiego w wyniku rozwoju ludzkości na przestrzeni ostatnich milionów lat. Ale nic tak nie wpłynęło na wzrost i szybkość zmian na Ziemi jak ludzka aktywność w ciągu ostatnich dwóch stuleci. Po raz pierwszy zmiany ekosystemów były tak intensywne i zachodziły na tka wielką skalę i z taką szybkością jak nigdy...
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Genetic ANFIS for scheduling in telecommunication networks
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Networks 2010 Conference in Warsaw, Poland
PublicationArtykuł sprawozdawczy z konferencji.
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Industrial computer networks and functional safety
PublicationW rozdziale monografii przedstawiono wybrane aspekty bezpieczeństwa funkcjonalnego na przykładzie przemysłowych sieci komputerowych stosowanych w obiektach infrastruktury krytycznej. Pierwszą cześć rozdziału poświęcono omówieniu klasycznych rozwiązań w zakresie sieci komputerowych. Drugą część rozdziału stanowi analiza przypadku typowej przemysłowej sieci komputerowej z uwzględnieniem aspektów bezpieczeństwa funkcjonalnego.
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The reliability of ring, star and hybrid networks
PublicationJednym z parametrów charakteryzującym jakość sieci jest jej niezawodność. Rozważono sieci o topologiach drzewiastych, gwiaździstych, pętlowych, wielo-pętlowych oraz mieszanych. Przyjęto następujący model uszkodzeń. Węzły oraz kanały sieci ulegają uszkodzeniom z określonym prawdopodobieństwem, uszkodzenia elementów sieci są od siebie statystycznie niezależne. Jako oceny niezawodności sieci przyjęto: średnią liczbę sprawnych par...
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<title>Intelligence in optical networks</title>
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Artificial Neural Networks for Comparative Navigation
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The Use of Semantic Networks for the Categorization of Prosumers
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Cost minimisation in multi-interface networks
PublicationPraca dotyczy problemu minimalizacji energii poprzez selektywne odłączanie urządzeń komunikacyjnych w wielointerfejsowych sieciach bezprzewodowych w taki sposób, by zapewnić realizację wymaganego grafu połączeń. Sformułowano problem optymalizacyjny, podano wyniki dotyczące jego trudności i zaproponowano algorytmy optymalizacyjne.
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Survivability analysis of scale-free networks
PublicationPraca dotyczy aspektów złośliwej kompromitacji stacji sieciowych poprzez epidemie wirusów komputerowych oraz ataki hackerskie. Opisano nowy autorski model analizy przeżywalności atakowanych sieci bezskalowych i ocenę metod zabezpieczeń. Pokazano wyniki modelowania efektywności środków powstrzymujących epidemie wirusów, polityk filtracji w ścianach ogniowych, efektywności blokowania adresów. Wszystkie wyniki są oryginalne i publikowane...
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Towards a classification of networks with asymmetric inputs
PublicationCoupled cell systems associated with a coupled cell network are determined by (smooth) vector fields that are consistent with the network structure. Here, we follow the formalisms of Stewart et al (2003 SIAM J. Appl. Dyn. Syst. 2, 609–646), Golubitsky et al (2005 SIAM J. Appl. Dyn. Syst. 4, 78–100) and Field (2004 Dyn. Syst. 19, 217–243). It is known that two non-isomorphic n-cell coupled networks can determine the same sets of...
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A Novel Multicast Architecture of Programmable Networks
PublicationIn the paper a multicast architecture for programmable networks based on separation of group management and network control tasks is proposed. Thanks to this separation, services which want to make use of multicast communications no longer have to implement low-level network functionalities and their operation is greatly simplified. Abstracting service’s view of the network into a fully connected cloud enables us to transparently...
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Communication Networks in the Service of the Environmental Monitoring
PublicationIn the paper selected issues relating to communication networks in the services of the environmental monitoring (EM) have been described. It is divided into three main parts: introduction, wire and wireless networks. At the beginning of the basic definitions were explained. The wire part focuses on a plain old telephone service (POTS), an integrated services digital network (ISDN), a digital subscriber line (DSL) and a fiber-optic...
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Quality Parameters in IMS/NGN Networks
PublicationThe Next Generation Network (NGN) architecture, including elements of the IP Multimedia Subsystem (IMS) concept, is a proposition of a telecommunication network dedicated to the needs of current and future information society. The main goal of NGN is to provide Quality of Service (QoS), for which proper network design is necessary with respect to among others standardized call processing performance parameters, including expected...
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Modelling fatalities on regional road networks
PublicationDuring the last decade Poland’s road fatalities went down by 44%. The trend differs from region to region. Effective road safetymanagement in regions requires tools for forecasting road safety measures and identifying factors influencing road fatality numbers. Mathematical models can provide such tools. They take into account local characteristics such as: demography, economy, infrastructure and motorization. Such models could...
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Survivability issues in IP-MPLS networks.
PublicationW pracy przedstawiono model oceny przeżywalności sieci IP-MPLS zaimplementowanej bezpośrednio na optycznej sieci WDM. Założono zaplanowane z góry zabezpieczenia aktywności ścieżek od krańca do krańca przez ścieżki węzłowo-rozłączne dedykowane bądź współdzielone. Przyjęto, że naprawa sieci zaczyna się w warstwie IP, a następnie obejmuje ścieżki optyczne. Zadanie optymalizacji tras IP i ich odwzorowanie na ścieżki optyczne zdekomponowano...
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Survivability issues in op-mpls networks
PublicationW pracy przedstawiono model oceny przeżywalności sieci IP-MPLS zaimplementowanej bezpośrednio na optycznej sieci WDM. Założono zaplanowane z góry zabezpieczenia aktywnych ścieżek od krańca do krańca przez ścieżki węzłowo-rozłączne dedykowane bądź współdzielone. Przyjęto, że naprawa sieci zaczyna się w warstwie IP, a następnie obejmuje ścieżki optyczne. Zadanie optymalizacji tras IP i ich odwzorowanie na ścieżki optyczne zdekomponowano...
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QoS Extensions for Flow-Awareness Networks
PublicationThe paper contains a description and research results of the proposal for distributed QoS extensions for Flow-Based Networking. These QoS extensions let the network accept or reject flows based on current network load and QoS promises for each of the flows. Proposed solution consists of two distributed components, each of them performing in every node, measurement system and access control. The solution could be applied in any...
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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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Problems of varistor quality assessment during exploitation
PublicationVaristors are commonly used elements which protect power supply networks against high-voltage surges or lightning. Therefore, quality and endurance of these elements is important to avoid losses when an expensive laboratory equipment would not be protected from random overvoltages. Additionally, excessive leakage currents generate serious costs due to high energy consumption. The paper presents shortly properties of varistors that...
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A Development of a Capacitive Voltage Divider for High Voltage Measurement as Part of a Combined Current and Voltage Sensor
PublicationThis article deals with the development of capacitive voltage divider for high voltage measurements and presents a method of analysis and optimization of its parameters. This divider is a part of a combined voltage and current sensor for measurements in high voltage power networks. The sensor allows continuous monitoring of the network distribution status and performs a quick diagnosis and location of possible network failures....
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Delamination Identification Using Global Convolution Networks
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Rearrangeability in multicast Clos networks is NP-complete
PublicationPrzestrajalność w polach Closa z połączeniami jeden do jeden jest problemem wielomianowym. W pracy pokazano, że w polach z połączeniami jeden do wiele problem ten jest NP zupełny.Three-stage elos networks are commutation networks with circuit switching. So far, graph theory has been very useful tool for solving issues related to these networks with unicast connections. This is so because if elos network is represented as a bipartite...
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RSVP-TE as a reservation protocol for optical networks
PublicationIn this paper, we consider the reservation of optical resources problem. We implement extensions for RSVP-TE (Resource ReSerVation Protocol with Traffic Engineering Extension) to achieve the new functionality for optical resources reservation. Based on ASON/GMPLS architecture we examine an open source implementation KOM RSVP-Engine and extend its functionality according to ITU-T and IETF recommendations. The transport plane consists...
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Applying artificial intelligence for cellular networks optimization
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Traffic Modeling in IMS-based NGN Networks
PublicationIn the modern world the need for accurate and quickly delivered information is becoming more and more essential. In order to fulfill these requirements, next generation telecommunication networks should be fast introduced and correctly dimensioned. For this reason proper traffic models must be identified, which is the subject of this paper. In the paper standardization of IMS (IP Multimedia Subsystem) concept and IMS-based NGN...
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Performance Evaluation of Preemption Algorithms in MPLS Networks
PublicationPreemption is a traffic engineering technique in Multiprotocol Switching Networks that enables creation of high priority paths when there is not enough free bandwidth left on the route. Challenging part of any preemption method is to select the best set of paths for removal. Several heuristic methods are available but no wider comparison had been published before. In this paper, we discuss the dilemmas in implementing preemption...
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Coordination of Traffic in Two-Way Street Networks
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Comparison of centralized and decentralized preemption in MPLS networks
PublicationPreemption is one of the crucial parts of the traffic engineering in MPLS networks. It enables allocation of high-priority paths even if the bandwidth on the preferred route is exhausted. This is achieved by removing previously allocated low-priority traffic, so as enough free bandwidth becomes available. The preemption can be performed either as a centralized or a decentralized process. In this article we discuss the differences...
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Service restoration in survivable networks under attacks
PublicationW artykule dokonano porównania jakości odtwarzania usług w przeżywalnych sieciach optycznych, uszkadzanych w wyniku awarii fizycznych oraz na skutek ataków. Przeanalizowano wariant ochrony ścieżek ('path protection') poprzez wyznaczane zawczasu ścieżki zabezpieczające. Z uwagi na NP-zupełność problemu optymalizacji doboru tras w przeżywalnych sieciach optycznych, zaproponowano efektywny algorytm heurystyczny SCNDP. Autorski symulator...
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Quality of service in optical burst switched networks
PublicationIn the paper analytical models of two service differentiation schemes for optical burst switched network: extended offset time based and PPS (Preemptive Priority Scheme) are revised. Also accordance of analytical models for those schemes is studied when complete class isolation is assumed. Furthermore authors introduce an analytical model which describes an effective degree of isolation when burst switched network employs both...
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Quality of service in optical burst switched networks
PublicationIn the paper analytical models of two service differentiation schemes for optical burst switched network: extended offset time based and PPS (Preemptive Priority Scheme) are revised. Also accordance of analytical models for those schemes is studied when complete class isolation is assumed. Furthermore authors introduce an analytical model which describes an effective degree of isolation when burst switched network employs both...
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Cost minimisation in unbounded multi-interface networks
PublicationW pracy badano problem odłączania niektórych urządzeń komunikacyjnych w wielointerfejsowych sieciach bezprzewodowych w taki sposób, by zapewnić realizację wymaganego grafu połączeń przy jednoczesnej minimalizacji zużycia energii. Sformułowano problem optymalizacyjny, podano wyniki dotyczące jego trudności i zaproponowano algorytmy optymalizacyjne dla wariantu, w którym liczba interfejsów komunikacyjnych jest potencjalnie nieograniczona...
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Cluster-Dependent Feature Selection for the RBF Networks
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AGENT-BASED APPROACH TO THE DESIGN OF RBF NETWORKS
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Trust Management Method for Wireless Sensor Networks
PublicationA Wireless Sensor Network (WSN) is a network of spatially distributed autonomous sensors to monitor physical or environmental conditions, such as temperature, sound, pressure, etc. and to cooperatively pass their data to the main location. The first wireless network that bore any real resemblance to a modern WSN is the Sound Surveillance System (SOSUS), developed by the United States Military in the 1950s to detect and track Soviet...
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DETERMINATION OF VERTICAL DISPLACEMENTS IN RELATIVE MONITORING NETWORKS
PublicationThe problem of determining displacements of objects is an important and current issue, in particular in terms of operational safety. This is a requirement that covers geodetic, periodic control measurements in order to determine horizontal and vertical displacements. The paper is focused on the analysis of vertical displacements. Geodetic measurements and their interpretation allow to reduce the risk of possible structural catastrophes....
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Service-based Resilience for Embedded IoT Networks
PublicationEmbedded IoT networks are the backbone of safety-critical systems like smart factories, autonomous vehicles, and airplanes. Therefore, resilience against failures and attacks should be a prior concern already in their design stage. In this study, we introduce a service-based network model as an MILP optimization problem for the efficient deployment of a service overlay to the embedded network by meeting QoS and resilience requirements....
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Robustness in Compressed Neural Networks for Object Detection
PublicationModel compression techniques allow to significantly reduce the computational cost associated with data processing by deep neural networks with only a minor decrease in average accuracy. Simultaneously, reducing the model size may have a large effect on noisy cases or objects belonging to less frequent classes. It is a crucial problem from the perspective of the models' safety, especially for object detection in the autonomous driving...
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Minimization of label usage in (G)MPLS networks
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