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Search results for: QUALITY OF NETWORK
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Using Statistical Methods to Estimate The Worst Case Response Time of Network Software Running on Indeterministic Hardware Platforms
PublicationIn this paper we investigate whether the statistical Worst Case Execution Time (WCET) estimation methods devised for embedded platforms can be successfully applied to find the Worst Case Response Time (WCRT) of a network application running on a complex hardware platform such as a contemporary commercial off-the-shelf (COTS) system. Establishing easy-to-use timing validation techniques is crucial for real-time applications and...
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Adaptive Algorithm of a Tap-Changer Controller of the Power Transformer Supplying the Radial Network Reducing the Risk of Voltage Collapse
Publicationhe development of renewable energy, including wind farms, photovoltaic farms as well as prosumer installations, and the development of electromobility pose new challenges for network operators. The results of these changes are, among others, the change of network load profiles and load flows determining greater volatility of voltages. Most of the proposed solutions do not assume a change of the transformer regulator algorithm....
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Is Digitalization Improving Governance Quality? Correlating Analog and Digital Benchmarks
PublicationThe digitalization of public governance and the resulting concept of electronic governance is a characteristic feature of contemporary information society. Both can be defined as the process and outcome of digital transformation: transformation of the “analog” version of governance into “digital” governance. Measuring both versions of governance against typical performance measures of efficiency, effectiveness, equity, openness...
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Analysis of Denoising Autoencoder Properties Through Misspelling Correction Task
PublicationThe paper analyzes some properties of denoising autoencoders using the problem of misspellings correction as an exemplary task. We evaluate the capacity of the network in its classical feed-forward form. We also propose a modification to the output layer of the net, which we called multi-softmax. Experiments show that the model trained with this output layer outperforms traditional network both in learning time and accuracy. We...
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Verification of the Analytical Traffic Model of a Multidomain IMS/NGN Using the Simulation Model
PublicationIn this paper we verify the previously proposed analytical traffic model of a multidomain Next Generation Network (NGN), which is standardized for delivering multimedia services based on the IP Multimedia Subsystem (IMS). For this reason a proper simulation model used, in which not theoretical queuing system models but the operation of real network elements and standardized call scenarios are accurately implemented. Consequently,...
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Call processing performance in multidomain IMS/NGN architecture
PublicationThe Next Generation Network (NGN) architecture, which bases on the IP Multimedia Subsystem (IMS) concept, is a proposition of a telecommunication network dedicated to the needs of the modern information society. The main goal of NGN is to provide Quality of Service (QoS), for which proper network design and dimensioning are necessary. This also requires appropriate traffic models, which should be efficient and not excessively complicated...
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NetBaltic System-Heterogenous Wireless Network for Maritime Communications
PublicationIn case of maritime communications, we observe a growing interest in deployment of multitask satellite-based solutions and development of new maritime-specific systems intended for improvements in safety of e-navigation. Analysis of different types of currently used maritime communication systems leads, however, to a conclusion that neither global and still very expensive satellite systems nor cheaper, but short-ranged transmission...
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Cooperative Data Transmission in Wireless Vehicular Networks
PublicationThe paper presents issues related to the cooperative transmission in wireless vehicular networks. Cooperative transmission involves the use of mobile terminals as relay stations to improve the transmission quality, improve network performance and reduce energy consumption. The paper presents the methods used to implement cooperative transmission and the types of cooperative networks.
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Quality Analysis of Audio-Video Transmission in an OFDM-Based Communication System
PublicationApplication of a reliable audio-video communication system, brings many advantages. With the spoken word we can exchange ideas, provide descriptive information, as well as aid to another person. With the availability of visual information one can monitor the surrounding, working environment, etc. As the amount of available bandwidth continues to shrink, researchers focus on novel types of transmission. Currently, orthogonal frequency...
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Activity coordination of capacitor banks and power transformer controllers in order to reduce power losses in the MV grid
PublicationOne of the main issues related to the optimization of the MV (middle voltage) network is to reduce losses of active and reactive power. Lower losses of active and reactive power give not only economic advantage, but also improvement of energy quality. The object of regulation that can be used for these purposes are transformer with On-Load Tap Changer and capacitor's banks. This paper presents results of analysis of the possibility...
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Badanie jakości sieci komórkowych w przededniu technologii 5G na wybranym przykładzie
PublicationWraz z rosnącą popularnością i dostępnością urządzeń mobilnych, zwiększa się liczba abonentów w sieci. Fakt ten prowadzi do wzrostu świadomości użytkowników, pod kątem jakości treści, które konsumują. Wielu dostawców usług oraz operatorów skupia swoje działania na monitorowaniu parametrów jakościowych QoN (Quality of Network) i QoS (Quality of Service). Niniejsza praca przed-stawia wyniki badań przeprowadzonych na terenie kampusu...
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An interval estimator for chlorine monitoring in drinking water distribution systems under uncertain system dynamics, inputs and chlorine concentration measurement errors
PublicationThe design of an interval observer for estimation of unmeasured state variables with application to drinking water distribution systems is described. In particular, the design process of such an observer is considered for estimation of the water quality described by the concentration of free chlorine. The interval observer is derived to produce the robust interval bounds on the estimated water quality state variables. The stability...
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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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Personalized nutrition in ageing society: redox control of major-age related diseases through the NutRedOx Network (COST Action CA16112)
PublicationA healthy ageing process is important when it is considered that one-third of the population of Europe is already over 50 years old, although there are regional variations. This proportion is likely to increase in the future, and maintenance of vitality at an older age is not only an important measure of the quality of life but also key to participation and productivity. So, the binomial “nutrition and ageing” has different aspects...
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DIAGNOSIS OF MALIGNANT MELANOMA BY NEURAL NETWORK ENSEMBLE-BASED SYSTEM UTILISING HAND-CRAFTED SKIN LESION FEATURES
PublicationMalignant melanomas are the most deadly type of skin cancer but detected early have high chances for successful treatment. In the last twenty years, the interest of automated melanoma recognition detection and classification dynamically increased partially because of public datasets appearing with dermatoscopic images of skin lesions. Automated computer-aided skin cancer detection in dermatoscopic images is a very challenging task...
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Message Inter-Arrival and Inter-Departure Time Distributions in IMS/NGN Architecture
PublicationCurrently is it assumed that requirements of the information society for delivering multimedia services will be satisfied by the Next Generation Network (NGN) architecture, which includes elements of the IP Multimedia Subsystem (IMS) solution. In order to guarantee Quality of Service (QoS), NGN has to be appropriately designed and dimensioned. Therefore, proper traffic models should be proposed and applied. This requires determination...
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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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Modelling Coarse Particulate Matter PM10 Concentration in the Tricity Area Using GIS
PublicationEnvironmental pollution is an issue of global concern, with Particulate Matter (PM) poisoning being a prime cause of lung cancer. This has led the European Commission to establish strict daily and annual PM concentration limits. The monitoring of air quality in major cities is the responsibility of European Member States. The Tricity, a 414.81 km 2 area in northern Poland, is monitored by a network of only 9 stations operated by...
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JAKOŚĆ USŁUG W ARCHITEKTURZE SIECI ASON/GMPLS A MECHANIZMY REZERWACJI ZASOBÓW
PublicationW artykule przedstawiono mechanizmy rezerwacji zasobów w architekturze sieci ASON/GMPLS, która spełnia wymagania nowoczesnych sieci optycznych, a jednocześnie umożliwia sterowanie siecią z gwarancją jakości usług. W artykule porównano dwa mechanizmy rezerwacji zasobów z gwarancją jakości i podejściem typu POOL. Efektywność prezentowanych mechanizmów zweryfikowano metodą symulacji komputerowej w środowisku OMNeT++.
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Determining QoS in the Video Telephony Service in an IP Environment
PublicationIP networks are indispensable nowadays. They are among the most efficient platforms. The constantly growing number of users and new services in these networks - the largest being the Internet - requires a good quality of any application used.Determining the QoS in real-time services is particularly important. This work is dedicated to exactly this aspect of the real-time service Video Telephony over IP (VToIP). First, the ITU-T...
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Enhancing Security of Advanced Metering Infrastructure by Introducing Threshold Attendance Protocol
PublicationThe industry pushes towards smart grid systems in order to resolve current limitations of the unidirectional legacy power grid infrastructure. By introducing Advanced Metering Infrastructure (AMI) as an integral part of the smart grid solution, the utility company obtains an invaluable tool to optimize its network, lower the operational costs, and improve quality of service. Unfortunately, introducing two-way communication poses...
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Simulation model for evaluation of QoS routing algorithm in large packet networks
PublicationThe variety of traffic transferred via current telecommunication networks includes also voice, which should meet quality requirements. One of mechanisms, which can support QoS in current packet networks, is routing. There exist many routing proposals which should introduce the QoS into the network but practically they don't. Following paper presents the realization of simulation model for evaluation of a new routing algorithm DUMBRA...
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Approximation of Message Inter-Arrival and Inter-Departure Time Distributions in IMS/NGN Architecture Using Phase-Type Distributions
PublicationCurrently it is assumed that requirements of the information society for delivering multimedia services will be satisfied by the Next Generation Network (NGN) architecture, which includes elements of the IP Multimedia Subsystem (IMS) solution. In order to guarantee Quality of Service (QoS), NGN has to be appropriately designed and dimensioned. Therefore, proper traffic models should be proposed and applied. This requires determination...
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Overview of cooperative communication methods
PublicationThe paper presents issues related to the cooperative communication in wireless networks. Cooperative com-munication involves the use of mobile terminals as relay stations to improve the transmission quality, improve network performance and reduce energy consumption. It is also possible to use several different data transmission standards. The paper presents the methods used to implement cooperative communication. The types of cooperative...
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Metody doboru miejsc zainstalowania zasobników energii w sieciach elektroenergetycznych niskiego napięcia
PublicationW związku z rosnącą liczbą źródeł odnawialnych przyłączanych do sieci niskiego napięcia (nn) jakość energii elektrycznej w tej sieci ulega pogorszeniu. Jedną z metod jej poprawiania jest instalowanie zasobników energii, tj. baterii akumulatorów, superkondensatorów czy kół zamachowych. Zasobniki energii są w stanie złagodzić dobową zmienność obciążenia, skompensować moc bierną i wyższe harmoniczne oraz zmniejszyć asymetrię obciążenia...
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Tool Wear Monitoring Using Improved Dragonfly Optimization Algorithm and Deep Belief Network
PublicationIn recent decades, tool wear monitoring has played a crucial role in the improvement of industrial production quality and efficiency. In the machining process, it is important to predict both tool cost and life, and to reduce the equipment downtime. The conventional methods need enormous quantities of human resources and expert skills to achieve precise tool wear information. To automatically identify the tool wear types, deep...
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Cost-Efficient Multi-Objective Design of Miniaturized Microwave Circuits Using Machine Learning and Artificial Neural Network
PublicationDesigning microwave components involves managing multiple objectives such as center frequencies, impedance matching, and size reduction for miniaturized structures. Traditional multi-objective optimization (MO) approaches heavily rely on computationally expensive population-based methods, especially when exe-cuted with full-wave electromagnetic (EM) analysis to guarantee reliability. This paper introduces a novel and cost-effective...
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Sterowanie optyczną siecią wielodomenową z hierarchiczną strukturą płaszczyzn sterowania
PublicationW artykule przedstawiono problem sterowania wielodomenową siecią optyczną z hierarchiczną strukturą płaszczyzn sterowania. Autorzy proponują wykorzystanie koncepcji sieci ASON/GMPLS, która spełnia wymagania nowoczesnych sieci optycznych, a jednocześnie umożliwia sterowanie wielodomenową siecią z gwarancją jakości usług. W artykule zaproponowano algorytm sterowania z gwarancją jakości, którego efektywność zweryfikowano metodą symulacji...
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Service and Path Discovery Extensions for Self-forming IEEE 802.11s Wireless Mesh Systems
PublicationWith the rapid growth of the quantity and capabilities of end-user electronic devices, both stationary and mobile, they are employed in increasing number of applications. In this situation, wireless network technologies begin to play a crucial role as networks access technologies, as cable-based solutions tend to be of limited utility in case of easily portable or mobile devices. Resulting development of wireless technologies reached...
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The Method of a Two-Level Text-Meaning Similarity Approximation of the Customers’ Opinions
PublicationThe method of two-level text-meaning similarity approximation, consisting in the implementation of the classification of the stages of text opinions of customers and identifying their rank quality level was developed. Proposed and proved the significance of major hypotheses, put as the basis of the developed methodology, notably about the significance of suggestions about the existence of analogies between mathematical bases of...
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Traffic model for evaluation of call processing performance parameters in IMS-based NGN
PublicationIn the modern world requirements for accurate and fast information distribution are becoming more and more important, which creates a strong necessity for appropriate telecommunication network architecture. Proposition of such an architecture is the Next Generation Network (NGN) concept, which in order to guarantee Quality of Service (QoS), should be correctly designed and dimensioned. For this reason proper traffic models must...
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Performance Models of a Multidomain IMS/NGN Service Stratum
PublicationThis paper quantifies call processing performance (CPP) of a multidomain IMS/NGN architecture, which was proposed to deliver current and future telecommunication services with strict quality requirements, independently of the transport network technologies. A realistic simulation model is used as a reference for evaluation of the analytical results, in which vari-ous types of queuing systems are applied to model the opera-tion...
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Mobile navigation system for visually impaired users in the urban environment
PublicationThis paper describes the prototype version of a mobile application supporting independent movement of theblind. Its objective is to improve the quality of life of visually impaired people, providing them with navigationalassistance in urban areas. The authors present the most important modules of the application. The module forprecise positioning using DGPS data from the ASG-EUPOS network as well as enhancements of positioning...
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Study on transmission quality in cellular 4G and 5G networks between 2019–2021: Impact of the COVID-19 pandemic on the level of provided services by operating base transceiver stations
PublicationThe COVID-19 pandemic has significantly limited user mobility, not least among students. Remote learning had a particular impact on resource allocation in relation to using terrestrial cellular networks, especially 4G systems in urban agglomerations. This paper presents the results of a quality evaluation of an outdoor environment, carried out between 2019 and 2021 on the campus of a technical university. Annual studies are conducted...
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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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On Software Unit Testing For Security and Performance Gain At Unit Level
PublicationPerformance and security are software (SW) application attributes situated on the opposite corners of system design. In the most drastic example the most secure component is the one totally isolated from the outside world, with communication performance reduced to zero level (e.g. disconnected physically from the network, placed inside a Faraday cage to eliminate possible wireless accessibility). On the other hand the most performance-optimized...
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On Software Unit Testing For Improving Security And Performance Of Distributed Applications
PublicationPerformance and security are software (SW) application attributes situated on the opposite corners of system design. In the most drastic example the most secure component is the one totally isolated from the outside world, with communication performance reduced to zero level (e.g. disconnected physically from the network, placed inside a Faraday cage to eliminate possible wireless accessibility). On the other hand the most performance-optimized...
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Monitoring of Chlorine Concentration in Drinking Water Distribution Systems Using an Interval Estimator
PublicationThis paper describes the design of an interval observer for the estimation of unmeasured quality state variables in drinking water distribution systems. The estimator utilizes a set bounded model of uncertainty to produce robust interval bounds on the estimated state variables of the water quality. The bounds are generated by solving two differential equations. Hence the numerical efficiency is sufficient for on-line monitoring...
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Food analysis using artificial senses.
PublicationNowadays, consumers are paying great attention to the characteristics of food such as smell, taste, and appearance. This motivates scientists to imitate human senses using devices known as electronic senses. These include electronic noses, electronic tongues, and computer vision. Thanks to the utilization of various sensors and methods of signal analysis, artificial senses are widely applied in food analysis for process monitoring...
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Event driven MPC for networked control systems
PublicationBecause of variable delays and stochastic data packets loss networked control systems require suitable algorithms to ensure stability of the control system and guarantee desired control performance. This paper presents the idea of an event driven approach with MPC controller. In opposition to network compensation, where standard regulators are used, the presented solution integrates network with plant. A MPC based controller is...
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Detecting type of hearing loss with different AI classification methods: a performance review
PublicationHearing is one of the most crucial senses for all humans. It allows people to hear and connect with the environment, the people they can meet and the knowledge they need to live their lives to the fullest. Hearing loss can have a detrimental impact on a person's quality of life in a variety of ways, ranging from fewer educational and job opportunities due to impaired communication to social withdrawal in severe situations. Early...
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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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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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Reliability And Safety As An Objective Of Intelligent Transport Systems In Urban Areas
PublicationTechnologies that use transport telematics offer tools for strengthening urban transport systems. They rationalise the use of the existing infrastructure and transport management systems, increase their reliability and safety and improve the transport behaviour of residents, while reducing the operating costs of transport. The main reason for using Intelligent Transport Systems (ITS) is the need to implement measures to reduce...
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Analysis of IMS/NGN call processing performance using G/G/1 queuing systems approximations
PublicationThe paper concerns the Next Generation Network (NGN), which is standardized for distribution of multimedia services based on the IP Multimedia Subsystem (IMS). To guarantee quality, accurate traffic models of IMS/NGN should be proposed. In the paper we compare results obtained with our analytical and simulation model of a single IMS/NGN domain, where various queuing systems are used in the analytical model (M/G/1 and approximations...
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A Novel Method for the Deblurring of Photogrammetric Images Using Conditional Generative Adversarial Networks
PublicationThe visual data acquisition from small unmanned aerial vehicles (UAVs) may encounter a situation in which blur appears on the images. Image blurring caused by camera motion during exposure significantly impacts the images interpretation quality and consequently the quality of photogrammetric products. On blurred images, it is difficult to visually locate ground control points, and the number of identified feature points decreases...
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LSTM-based method for LOS/NLOS identification in an indoor environment
PublicationDue to the multipath propagation, harsh indoor environment significantly impacts transmitted signals which may adversely affect the quality of the radiocommunication services, with focus on the real-time ones. This negative effect may be significantly reduced (e.g. resources management and allocation) or compensated (e.g. correction of position estimation in radiolocalisation) by the LOS/NLOS identification algorithm. This paper...
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A Reputation Scheme to Discourage Selfish QoS Manipulation in Two-Hop Wireless Relay Networks
PublicationIn wireless networks, stations can improve their received quality of service (QoS) by handling packets of source flows with higher priority. Additionally, in cooperative relay networks, the relays can handle transit flows with lower priority. We use game theory to model a two-hop relay network where each of the two involved stations can commit such selfish QoS manipulation. We design and evaluate a reputation-based incentive scheme...
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Detection of debonding in reinforced concrete beams using ultrasonic transmission tomography and hybrid ray tracing technique
PublicationThis paper concerns inspection of reinforced concrete elements, with particular emphasis on assessing the quality of the adhesive connection between steel and concrete. A novel theoretical model was developed to determine the paths of transmitted, refracted and reflected elastic waves as well as a creeping wave propagated along the inclusion surface. Imaging the internal structure of tested beams was based on wave propagation measurements...