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Search results for: DC COLLECTOR NETWORK
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Resilient Routing in Communication Networks - A Systems Perspective
PublicationThis practically focused monograph addresses the latest issues of resilient routing in networked systems. It consists of three parts and offers an in-depth introduction to the resilience of networked systems (Part I), a detailed description of schemes of resilient routing (Part II), and examples of the application of resilience mechanisms in selected communication scenarios (Part III). Topics and features: presents the essentials...
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Trust-Based Model for the Assessment of the Uncertainty of Measurements in Hybrid IoT Networks
PublicationThe aim of this paper is to introduce a NUT model (NUT: network-uncertainty-trust) that aids the decrease of the uncertainty of measurements in autonomous hybrid Internet of Things sensor networks. The problem of uncertainty in such networks is a consequence of various operating conditions and varied quality of measurement nodes, making statistical approach less successful. This paper presents a model for decreasing the uncertainty...
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Experimental test results of an automatic voltage regulator with independent phase voltage controllers
PublicationThe growing number of distributed renewable energy sources and dynamic constant-power loads (e.g. electric vehicle charging stations) pose new challenges for network operators. These changes result in alterations to network load profiles and load flows, leading to greater voltage volatility. One effective solution to these problems can be the use of automatic voltage regulators (AVRs), which stabilize and symmetrize voltage output,...
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Optimum Choice of Randomly Oriented Carbon Nanotube Networks for UV-Assisted Gas Sensing Applications
PublicationWe investigated the noise and photoresponse characteristics of various optical transparencies of nanotube networks to identify an optimal randomly oriented network of carbon nanotube (CNT)-based devices for UV-assisted gas sensing applications. Our investigation reveals that all of the studied devices demonstrate negative photoconductivity upon exposure to UV light. Our studies confirm the effect of UV irradiation on the electrical...
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Efficiency of the Use of LTE System Radio Resources in Highway Transport Enironment
PublicationThe paper describes the problem of analysis of throughput-coverage characteristics of the LTE system. Simulation results of the efficiency of the use of LTE radio resources are presented. Simulation studies on the basis of original model of the LTE network simulator were carried out. In addition, the evaluation of throughput for a single connection, and available capacity were evaluated in the context of the use of the same...
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Scalable Maintenance of Address Mapping and Autodetecion in Environments Where Agents are Uncapable of Self-Registration
PublicationWhen 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,...
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Developing a Low SNR Resistant, Text Independent Speaker Recognition System for Intercom Solutions - A Case Study
PublicationThis article presents a case study on the development of a biometric voice verification system for an intercom solution, utilizing the DeepSpeaker neural network architecture. Despite the variety of solutions available in the literature, there is a noted lack of evaluations for "text-independent" systems under real conditions and with varying distances between the speaker and the microphone. This article aims to bridge this gap....
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Knowledge management in the IPv6 migration process
PublicationThere are many reasons to deploy IPv6 protocol with IPv4 address space depletion being the most obvious. Unfortunately, migration to IPv6 protocol seems slower than anticipated. To improve pace of the IPv6 deployment, authors of the article developed an application that supports the migration process. Its main purpose is to help less experienced network administrators to facilitate the migration process with a particular target...
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Enhancing Resilience of FSO Networks to Adverse Weather Conditions
PublicationOptical wireless networks realized by means of gigabit optical wireless communication (OWC) systems are becoming, in a variety of applications, an important alternative, or a complementary solution, to their fiber-based counterparts. However, performance of the OWC systems can be considerably degraded in periods of unfavorable weather conditions, such as heavy fog, which temporarily reduce the effective capacity of the network....
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Collision‐Aware Routing Using Multi‐Objective Seagull Optimization Algorithm for WSN‐Based IoT
PublicationIn recent trends, wireless sensor networks (WSNs) have become popular because of their cost, simple structure, reliability, and developments in the communication field. The Internet of Things (IoT) refers to the interconnection of everyday objects and sharing of information through the Internet. Congestion in networks leads to transmission delays and packet loss and causes wastage of time and energy on recovery. The routing protocols...
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Design of Cost-Efficient Optical Fronthaul for 5G/6G Networks: An Optimization Perspective
PublicationCurrently, 5G and the forthcoming 6G mobile communication systems are the most promising cellular generations expected to beat the growing hunger for bandwidth and enable the fully connected world presented by the Internet of Everything (IoE). The cloud radio access network (CRAN) has been proposed as a promising architecture for meeting the needs and goals of 5G/6G (5G and beyond) networks. Nevertheless, the provisioning of cost-efficient...
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5G/6G optical fronthaul modeling: cost and energy consumption assessment
PublicationIn fifth generation (5G) and the future beyond 5G (6G) radio access networks (RANs), the cost of fronthaul deployment is a main challenge for mobile network operators. Depending on different constraints, there are various solutions to deploy an efficient fronthaul. Fiber-optic-based fronthaul offers long-term support with regard to a rapid increase in capacity demands. When fiber connections, either point-to-point (P2P) or point-to-multipoint...
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Układy sterowania bramkowego tranzystorów z węglika krzemu SiC JFET w falownikach napięcia
PublicationZastosowanie technologii węglika krzemu (SiC) w falownikach napięcia pozwala na zwiększenie częstotliwości przełączeń oraz temperatury pracy przyrządów półprzewodnikowych. W celu zapewnienia minimalizacji strat oraz określonych właściwości dynamicznych tranzystorów z węglika krzemu wymagane jest stosowanie zaawansowanych układów sterowania bramkowego. W referacie przedstawiono analizę teoretyczną, wyniki badań symulacyjnych oraz...
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Bezczujnikowe sterowanie generatorem klatkowym w stanach lotnego startu elektrowni wiatrowej
PublicationElektrownie wiatrowe pracujące na sieć i wyposażone w przekształtniki dwukierunkowe AC-DC-AC, dzięki zastosowaniu generatorówindukcyjnych klatkowych mogą zapewniać efektywne generowanie energii w szerokim zakresie zmian wiatru. W artykule przedstawiono analizęlotnego startu elektrowni wiatrowej z generatorem klatkowym i cyfrowym układem sterowania. Przedstawiono wyniki symulacji lotnego startu generatora klatkowego w układzie ze...
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Determination of the ionic conductivity of Sr-doped lanthanum manganite by modified Hebb–Wagner technique
PublicationThe Hebb–Wagne rpolarization method with the electron blocking electrode has been discussed in this paper in aim to determine a partial ionic conductivity of Sr-doped lanthanum manganite.The “limiting current” in the proposed system was measured using the two-point DC technique with additional Pt electrode between LSM and blocking electrode.The electrochemical model based on bulk diffusion processes and Boltzmann statistics has...
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The domination of ionic conductivity in tetragonal phase of the organometal halide perovskite CH3NH3PbI3-xClx
PublicationOrganometal trihalide perovskites have recently gained extreme attention due to their high solar energy conversion in photovoltaic cells. Here, we investigate the contribution of iodide ions to a total conductivity of the mixed lead halide perovskite CH3NH3PbI3−xClx with a use of the modified DC Hebb–Wagner polarization method. It has been identified that an ionic conductivity dominates in tetragonal phase which is associated with room...
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Evaluation of Praseodymium and Gadolinium Doped Ceria as a Possible Barrier Layer Material for Solid Oxide Cells
PublicationIn this work, nanocrystalline layers based on the Pr, Gd co-doped CeO2 were investigated. For the preparation of thin layers, lowtemperature spray pyrolysis technique was used. Different stoichiometries of the layers were produced for comparison on polished sapphire substrates. The microstructure of the prepared thin layers was studied by scanning electron microscopy (SEM), energydispersive X-ray spectroscopy (EDS) and X-ray diffractometry (XRD)....
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Modified sliding mode control for seamless integration of P.V. energy in A.C. grid
PublicationSolar energy is a potentially abundant and reliable source of renewable energy. While it can undoubtedly increase grid reliability and efficiency, the inverted voltage generated from PV. sources may introduce distortion into the AC. grid. The proposed control mechanism, modified sliding mode control (MSMC), can seamlessly integrate the inverter output generated by obtaining DC. voltage from the boost converter linked with the PV....
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President and Manager of the court versus networking in justice system - "Extending of Delimitation"
PublicationCurrent knowledge and empirical studies concering the networks collaboration in public sector, the role of decision-making centre in the building of network structure, strategy formulation and evaluation is fragmentary.
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DST-Based Detection of Non-cooperative Forwarding Behavior of MANET and WSN Nodes
Publication. Selfish node behavior can diminish the reliability of a mobile ad hoc network (MANET) or a wireless sensor network (WSN). Efficient detection of such behavior is therefore essential. One approach is to construct a reputation scheme, which has network nodes determine and share reputation values associated with each node; these values can next be used as input to a routing algorithm to avoid end-to-end routes containing ill-reputed...
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E-Learning Service Management System For Migration Towards Future Internet Architectures
PublicationAs access to knowledge and continuous learning are among the most valuable assets in modern, technological society, it is hardly surprising that e-learning solutions can be counted amongst the most important groups of services being deployed in modern network systems. Based on analysis of their current state-of-the-art, we decided to concentrate our research and development work on designing and implementing a management system...
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The IPV6 Deployment - Best practices
PublicationThe new Internet Protocol IPv6 has been regarded for quite a long time as the only option to ensure uninterrupted operation for the Internet service providers andend-users in the current Internet. The article presents important faets about the IPv6, including current statistics of the IPv4 usage, the IPv6 statistics for Poland comparing to the whole Internet. Moreover, this paper shows important aspeets of migration from IPv4 towards...
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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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Photovoltaic module temperature stabilization with the use of phase change materials
PublicationThe worldwide growth of photovoltaics (PVs) has formed an exponential curve for more than four decades. During this period of time, PVs have evolved from a pure niche market of small-scale applications towards becoming a mainstream electricity source. The influence of temperature on the electrical parameters of crystalline silicon solar cells and solar modules is well described in the literature. In order to diminish these effects,...
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A new concept of PWM duty cycle computation using the Barycentric Coordinates in a Three-Dimensional voltage vectors arrangement
PublicationThe paper presents a novel approach to the Pulse Width Modulation (PWM) duty cycle computing for complex or irregular voltage vector arrangements in the two (2D) and three–dimensional (3D) Cartesian coordinate systems. The given vectors arrangement can be built using at least three vectors or collections with variable number of involved vectors (i.e. virtual vectors). Graphically, these vectors form a convex figure, in particular,...
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Control Strategy of a Five-Phase Induction Machine Supplied by the Current Source Inverter With the Third Harmonic Injection
PublicationIn the five-phase induction machine (IM), it is possible to better use the electromagnetic circuit than in the three-phase IM. This requires the use of an adequate converter system which will be supplied by an induction machine. The electric drive system described, in this article, includes the five-phase induction machine supplied by the current source inverter (CSI). The proposed novelty—not presented previously—is the control...
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UV-assisted fluctuation-enhanced gas sensing by ink-printed MoS2 devices
PublicationIn this work, MoS2 flakes were printed on ceramic substrates and investigated toward 1–10 ppm of nitrogen dioxide (NO2), 2–12 ppm of ammonia (NH3), and 2–12 ppm acetone (C3H6O) under UV light (275 nm). The structure of overlapping MoS2 flakes and UV light assistance affected high responsivity to NO2 when DC resistance was monitored, and superior sensitivity to NH3 was obtained from the low-frequency noise spectra. MoS2 exhibited...
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Magnetic anisotropy and structural flexibility in the f ield-induced single ion magnets [Co{(OPPh2) (EPPh2)N}2], E = S, Se, explored by experimental and computational methods
PublicationDuring the last few years, a large number of mononuclear Co(II) complexes of various coordination geometries have been explored as potential single ion magnets (SIMs). In the work presented herein, the Co(II) S = 3/2 tetrahedral [Co{(OPPh2)(EPPh2)N}2], E = S, Se, complexes (abbreviated as CoO2E2), bearing chalcogenated mixed donor-atom imidodiphosphinato ligands, were studied by both experimental and computational techniques. Specifically,...
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Dynamically positioned ship steering making use of backstepping method and artificial neural networks
PublicationThe article discusses the issue of designing a dynamic ship positioning system making use of the adaptive vectorial backstepping method and RBF type arti cial neural networks. In the article, the backstepping controller is used to determine control laws and neural network weight adaptation laws. e arti cial neural network is applied at each time instant to approximate nonlinear functions containing parametric uncertainties....
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A bound on the number of middle-stage crossbars in f-cast rearrangeable Clos networks
PublicationIn 2006 Chen and Hwang gave a necessary and sufficient condition under which a three-stage Clos network is rearrangeable for broadcast connections. Assuming that only crossbars of the first stage have no fan-out property, we give similar conditions for f-cast Clos networks, where f is an arbitrary but fixed invariant of the network. Such assumptions are valid for some practical switching systems, e.g. high-speed crossconnects....
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Filozofia sieci 5G - radioinformatyka i wirtualizacja. Część 2. Wirtualny system 5G.
PublicationPrzedstawiono najważniejsze właściwości sieci 5G z punktu widzenia istoty jej działania. Uporządkowano najistotniejsze pojęcia służące do opisu sieci 5G, zwłaszcza w kontekście rozwiązań softwarowych, wirtualizacji sieci oraz jej architektury fizycznej i funkcjonalnej. Wprowadzono i zdefiniowano wiele pojęć wynikających z nowej ery rozwoju radiokomunikacji, w tym pojęcie radioinformatyki, systemu radioinformatycznego, sieci radioinformatycznej....
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Conception and design of a hybrid exciter for brushless synchronous generator. Application for autonomous electrical power systems = Koncepcja i projekt hybrydowej wzbudnicy bezszczotkowego generatora synchronicznego. Zastosowanie w autonomicznych systemach elektroenergetycznych.
PublicationThis paper covers a subject of a hybrid excitation system for a brushless synchronous generator working with variable speed in an autonomous energy generation system (e.g. airplane power grid). A hybrid excitation system (hybrid exciter) means a synchronous machine with wound-field and permanent magnet excitation. The hybrid exciter supply a dc field current to the synchronous generator field winding through a rotating rectifier....
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Badania eksperymentalne prostownika osiemnastopulsowego o mocy 150 kVA z opcjonalnym szeregowym energetycznym filtrem aktywnym
PublicationW artykule przedstawiono system sterowania oraz wybrane wyniki badań eksperymentalnych przekształtnika AC / DC składającego się z osiemnastopulsowego diodowego prostownika na bazie dławików sprzężonych i szeregowego energetycznego filtra aktywnego. Przebadano i porównano trzy konfiguracje przekształtnika o mocy 150kVA: (1) osiemnastopulsowy prostownik bez dodatkowych elementów, (2) prostownik z dodatkowym dławikiem sieciowym oraz...
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Oddziaływanie przekształtników energoelektronicznych dużej mocy na jakość energii elektrycznej
PublicationW referacie przedstawiono zagadnienia związane z oddziaływaniem układów przekształtnikowych AC/DC na sieć zasilającą poprzez generowanie prądów odkształconych. Przedstawione wyniki badań porównawczych emisji zaburzeń przewodzonych układów prostownikowych klasycznych (diodowych) oraz nowoczesnych (tranzystorowych) wykazują znaczne zwiększenie emisji w zakresie stosowanych częstotliwości modulacji w typowych aplikacjach przemysłowych....
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Analytical fluctuation enhanced sensing by resistive gas sensors
PublicationResistance fluctuations across polarised resistive gas sensors were studied in detail to evaluate sensor working conditions for detecting methane and ammonia at various concentrations. The 1/f noise component typically dominates other noise sources up to a few kHz and can be utilised to improve gas selectivity when compared with measurements of the sensor DC resistance. The Arrhenius plot was created and the activation energy for...
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SAMPLE-AND-HOLDING METHOD FOR GAS SENSING APPLIED FOR RESISTANCE GAS SENSORS
PublicationThe DC resistance of a Taguchi gas sensor is influenced by the ambient gas. To improve the selectivity and sensitivity of a sensor the fluctuation enhanced sensing (FES) was used. The paper proposes a novel methodology of utilizing FES technique that sample composition of an ambient atmosphere and hold it for further processing (sample-and-holding technique). The method uses the heated gas sensor to sample an ambient atmosphere...
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Jakość usług w optycznej sieci wielodomenowej z hierarchiczną strukturą płaszczyzn sterowania
PublicationW rozprawie przedstawiono przegląd architektur sieci z gwarancją jakości klas usług oraz stan prac w zakresie realizacji optycznych sieci ASON, GMPLS oraz ASON/GMPLS. Opisano wymagania i zaawansowanie prac w realizacji sieci ASON/GMPLS z hierarchiczną strukturą płaszczyzn sterowania oraz problemy związane z zagadnieniem jakości klas usług w tej sieci. Zaprezentowano założenia, koncepcję oraz realizację modelu symulacyjnego optycznej...
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Clothes Detection and Classification Using Convolutional Neural Networks
PublicationIn this paper we describe development of a computer vision system for accurate detection and classification of clothes for e-commerce images. We present a set of experiments on well established architectures of convolutional neural networks, including Residual networks, SqueezeNet and Single Shot MultiBox Detector (SSD). The clothes detection network was trained and tested on DeepFashion dataset, which contains box annotations...
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Instrumental measurement of odour nuisance in city agglomeration using electronic nose
PublicationThe paper describes an operation principle of odour nuisance monitoring network in a city agglomeration. Moreover, it presents the results of investigation on ambient air quality with respect to odour obtained during six-month period. The investigation was carried out using a network comprised of six prototypes of electronic nose and Nasal Ranger field olfactometers employed as a reference method. The monitoring network consisted...
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Using Long-Short term Memory networks with Genetic Algorithm to predict engine condition
PublicationPredictive maintenance (PdM) is a type of approach for maintenance processes, allowing maintenance actions to be managed depending on the machine's current condition. Maintenance is therefore carried out before failures occur. The approach doesn’t only help avoid abrupt failures but also helps lower maintenance cost and provides possibilities to manufacturers to manage maintenance budgets in a more efficient way. A new deep neural...
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Neural Approximators for Variable-Order Fractional Calculus Operators (VO-FC)
PublicationThe paper presents research on the approximation of variable-order fractional operators by recurrent neural networks. The research focuses on two basic variable-order fractional operators, i.e., integrator and differentiator. The study includes variations of the order of each fractional operator. The recurrent neural network architecture based on GRU (Gated Recurrent Unit) cells functioned as a neural approximation for selected...
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Deep-Learning-Based Precise Characterization of Microwave Transistors Using Fully-Automated Regression Surrogates
PublicationAccurate models of scattering and noise parameters of transistors are instrumental in facilitating design procedures of microwave devices such as low-noise amplifiers. Yet, data-driven modeling of transistors is a challenging endeavor due to complex relationships between transistor characteristics and its designable parameters, biasing conditions, and frequency. Artificial neural network (ANN)-based methods, including deep learning...
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An Algorithm for Optimizing the Determination of Cycling Routes on the Example of the Gdansk Agglomeration
PublicationPhysical activity is an essential part of a healthy lifestyle. One of the manifestations of the change in a society type from consumer to information one is the understanding of the importance of ecology and a healthy lifestyle. This is evident, inter alia, in the inventiveness and involvement of the society in the start-up and solutions referred to as the Smart City. One example is the development of e-bike rental and local investments...
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A spice equivalent circuit for modeling the performance of dual frequency echo-sounder
PublicationThe paper presents novel network equivalent circuit of piezoceramic circular disc transducers that takes into account thickness and radial mode of vibrations. The starting point of the analysis is 4-port description of circular disc element representing the solution of wave equation set in radial and thickness directions. The approximate solution for harmonic case is represented in the form of 4x4 matrix, which is synthesised and...
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The networking of the justice system as part of public court networks
PublicationThe goal of this paper is to look at the organizational structure of the justice system and provide the answer to the basic question of the possible network relations, their force, and imapct. As part od the paper, I have defined public inetrorganisational court network, dividing them into regulatory inter-organisational networks nad voluntary inetrorganisational networks. Emphasis has also been placed on the benefits and threats...
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total number and biomass of bacteria in drinking water distribution systems.
PublicationIn the vast water supply network using traditional methods of treatment it is often impossible to maintain a constant and acceptable microbiological quality of water. In Poland the main reason of bacterial re-growth is presence of organic matter and nutrients in the circulating water and prolonged water retention in the network systems due to the decrease of water consumption, which has been observed for the last 20 years. In the...
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SIMULATION MODEL OF ASON/GMPLS ARCHITECTURE
PublicationGrowing demands of information society concerned with sophisticated applications could be satisfied by ASON/GMPLS architecture comprehended as Automatically Switched Optical Network (ASON) with Generalized Multi-Protocol Label Switching (GMPLS). The ASON/GMPLS proposition represents the future direction of Next Generation Network (NGN) architecture. Therefore considerable work has to be done to examine this solution. In this aspect...
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Resilience of 5G Mobile Communication Systems to Massive Disruptions
PublicationThis chapter discusses vital techniques to enhance the resilience of 5G systems. It starts with dependability assessment of 5G networks. Next, it describes (a) the frequency fallback technique to improve availability and survivability of 5G services, (b) segment interleaving scheme to enhance communications resilience between base stations and the remaining part of the network and (c) multi-operator protection to address the resilience...
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Influence of Dielectric Overlay Permittivity on Size and Performance of Miniaturized ESPAR Antenna
PublicationIn this paper, influence of dielectric overlay permittivity on miniaturized ESPAR antenna parameters is presented. ESPAR antenna is a low-cost and energy-efficient way to implement beam steering capability to a node and improve network performance. The antenna size reduction is obtained by embedding its active and passive elements in ABS based materials of relative permittivity equal to 4, 5.5 and 7.5 in order to achieve network...
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Energy efficient indoor localisation for narrowband internet of things
PublicationThere are an increasing number of Narrow Band IoT devices being manufactured as the technology behind them develops quickly. The high co-channel interference and signal attenuation was seen in edge Narrow Band IoT devices make it challenging to guarantee the service quality of these devices. To maximize the data rate fairness of Narrow Band IoT devices, a multi-dimensional indoor localization model is devised, consisting of...