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Search results for: WIRELESS MESH NETWORKS
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Radio Link Measurement Methodology for Location Service Applications
PublicationThe aim of this paper is the methodology of measurements executed in a radio link for the realization of radiolocation services in radiocommunication networks, particularly in cellular networks. The main results of the measurements obtained in the physical layer of the universal mobile telecommunications system (UMTS) are introduced. A new method for the utilization of the multipath propagation phenomenon to improve the estimation...
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ESPAR Antenna-Based WSN Node With DoA Estimation Capability
PublicationIn this paper, we present a low-cost energy-efficient electronically steerable parasitic array radiator (ESPAR) antenna-based wireless sensor network (WSN) node designed for IEEE 802.15.4 standard that is capable of performing direction of arrival (DoA) estimation in real-life outdoor environments. To this end, we propose the WSN node architecture, design and realization that utilizes NXP JN5168 radio frequency (RF) wireless transceiver...
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Training of Deep Learning Models Using Synthetic Datasets
PublicationIn order to solve increasingly complex problems, the complexity of Deep Neural Networks also needs to be constantly increased, and therefore training such networks requires more and more data. Unfortunately, obtaining such massive real world training data to optimize neural networks parameters is a challenging and time-consuming task. To solve this problem, we propose an easy-touse and general approach to training deep learning...
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Utilization of a Non-Linear Error Function in a Positioning Algorithm for Distance Measurement Systems Designed for Indoor Environments
PublicationA new positioning algorithm for distance measurement systems is outlined herein. This algorithm utilizes a non-linear error function which allows us to improve the positioning accuracy in highly difficult indoor environments. The non-linear error function also allows us to adjust the performance of the algorithm to the particular environmental conditions. The well-known positioning algorithms have limitations, mentioned by their...
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Mechanical compatibility of implants used in hernia repair with abdominal wall
PublicationThe paper deals with a membrane model of a synthetic surgical mesh for treatment of abdominal hernia. The authors analyse the compatibility of two implant types with the human wall: Dualmesh Gore and Proceed. The finite element method is applied to simulate tjhe behavior of the proposed model. Due fact that recurrences are usually caused by connection failure, this study is focused on reaction forces in supports representing the...
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Macro-elements and Model Order Reduction for Efficient Three-Dimensional FEM Analysis
PublicationAn efficient model order reduction (MOR) methodology for three dimensional vector finite element method (FEM) is developed to accelerate simulations of the structures containing features that cause strong variations of mesh density. As the result of presented algorithm, FEM subsystems of equations corresponding to the selected refined region are converted into a very compact sets of linear equations, called macro-elements.Numerical...
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Rapid dimension scaling of triple-band antennas by means of inverse surrogate modeling
PublicationGeometry scaling of antennas, i.e., finding optimum dimensions of the structure for given operating conditions and material parameters is an important yet challenging problem. In this paper, we discuss fast dimension scaling of triple-band antennas with respect to operating frequencies. We adopt the inverse surrogate modeling approach where the surrogate model is a function of the three operating frequencies of the antenna and...
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Prevention of resonance oscillations in gear mechanisms using non-circular gears
PublicationOne of the main disadvantages of gear mechanisms is the occurrence of noise and vibrations. This study investigated the applicability of non-circular gears for preventing resonance oscillations in gear mechanisms. The influence of a small deviation of the gear centrodes from the nominal circles on kinematic and oscillatory characteristics was analysed. It was shown that a larger deviation results in a smaller resonance amplitude...
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Application possibilities of LBN for civil engineering issues
PublicationBayesian Networks (BN) are efficient to represent knowledge and for the reasoning in uncertainty. However the classic BN requires manual definition of the network structure by an expert, who also defines the values entered into the conditional probability tables. In practice, it can be time-consuming, hence the article proposes the use of Learning Bayesian Networks (LBN). The aim of the study is not only to present LBN, which can...
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Open-Set Speaker Identification Using Closed-Set Pretrained Embeddings
PublicationThe paper proposes an approach for extending deep neural networks-based solutions to closed-set speaker identification toward the open-set problem. The idea is built on the characteristics of deep neural networks trained for the classification tasks, where there is a layer consisting of a set of deep features extracted from the analyzed inputs. By extracting this vector and performing anomaly detection against the set of known...
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Reliable testbed for indoor positioning systems
PublicationThis paper proposes a test environment for indoor localization system, based on radio wave propagation prosperities. The following sections presents variety of problems from the assessment of the existing localization system to the analysis of inconveniences which occur when comparison of different localization systems is implemented. The problem is associated with different testing environments presented in published papers is...
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System Weryfikacji Autentyczności Podpisu Odręcznego
PublicationW referacie przedstawiono system statycznej i dynamicznej weryfikacji autentyczności podpisu odręcznego, składanego piórem biometrycznym, wyposażonym w 2 akcelerometry, 2 żyroskopy i 3 czujniki ścisku, na rezystancyjnej powierzchni dotykowej, łączącym się bezprzewodowo z urządzeniami komputerowymi. We wstępie przedstawiono architekturę sieciową wielomodalnego systemu biometrii. Przedstawiono warstwę sprzętową systemu weryfikacji...
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Validation of a virtual test environment for C2X communication under radio jamming conditions
PublicationIn this paper, we propose a novel car-2-x communication security testing methodology in the physical layer of wireless systems. The approach is dedicated to automated testing of autonomous vehicles and it is essential for such complex systems operation, especially with regard to safety and security issues. It is based on scenario-driven testing in virtual and real test environments created from collected or simulated data. The...
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Compensation Topologies in IPT Systems: Standards, Requirements, Classification, Analysis, Comparison and Application
PublicationWireless power transfer devices are becoming more relevant and widespread. Therefore, an article is devoted to a review, analysis and comparison of compensation topologies for an inductive power transfer. A new classification of topologies is developed. A lot of attention is paid to the problems of the physical fundamentals of compensation work, standards, safety, and five main topology requirements. It is determined, that topologies...
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Isogeometric Shell FE Analysis of the Human Abdominal Wall
PublicationIn this paper a nonlinear isogeometric Kirchhoff-Love shell model of the human abdominal wall is proposed. Its geometry is based on in vivo measurements obtained from a polygon mesh that is transformed into a NURBS surface, and then used directly for the finite element analysis. The passive response of the abdominal wall model under uniform pressure is considered. A hyperelastic membrane model based on the Gasser-Ogden-Holzapfel...
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Dynamics of mechanical model of implant-tissue system in ventral hernia repair
PublicationThe paper deals with a finite element modelling of implants in the problem of ventral hernia repair. The synthetic mesh implanted in the abdomen during surgery is here modelled as a membrane structure. Thesystem undergoes the internal abdominal pressure that occurs during the postoperative cough, the load identified in the literature as the main cause of the connection failure and hernia recurrence. The model can be used to estimate...
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Multipath routing for quality of service differentiation and network capacity optimization in broadband low-earth orbit systems
PublicationThis paper shows the importance of employing multiple different paths for routing in Inter-Satellite Link (ISL) networks in broadband Low-Earth Orbit (LEO) satellite systems. A theoretical analysis is presented and a routing concept is proposed to demonstrate three facts that make multipath routing especially important in broadband LEO networks: (1) differences in the propagation delays have a much greater impact on end-to-end...
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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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A method for testing the wide-sense stationary uncorrelated scattering assumption fulfillment for an underwater acoustic channel
PublicationWide-sense stationary and uncorrelated scattering (WSSUS) assumptions are often applied for the statistical description of wireless communication channels. However, in the case of underwater acoustic channels the WSSUS model is of limited value. The degree of similarity of in-phase and quadrature components of the channel impulse response, measured with the use of bandpass modulated signals, can be used as an indicator of WSSUS...
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Rozproszone systemy teleinformatyczne: inteligencja, autonomia, racjonalność i bezpieczeństwo kooperacji
PublicationWzrostowi inteligencji i autonomii podmiotów komunikacji systemów teleinformatycznych towarzyszy rozszerzanie paradygmatu analizy i projektowania w stronę podmiotów indywidualnie racjonalnych (egoistycznych). Wymaga to zastosowania metod teorii gier niekooperatywnych. W referacie pokazano przykłady zachowań egoistycznych określonych jako "wymuszanie pierwszeństwa" i "fałszywe tablice" odpowiednio w środowisku wireless multihoming...
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QoS w lokalnych sieciach bezprzewodowych.
PublicationZaprezentowano dwa najpopularniejsze obecnie rozwiązania lokalnych sieci bezprzewodowych (Wireless LAN - WLAN). Zarówno sieci standardu IEEE 802.11 jak i ETSI HIPERLAN/2, są postrzegane jako istotne elementy systemów łączności bezprzewodowej czwartej generacji (4G). Ze względu na ograniczoną szerokość pasma radiowego, w sieciach tych niebagatelną rolę zaczynają odgrywać mechanizmy dopasowujące jakość obsługi (QoS) do wymagań aplikacji...
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QoS w lokalnych sieciach bezprzewodowych
PublicationZaprezentowano dwa najpopularniejsze obecnie rozwiązania lokalnych sieci bezprzewodowych (Wireless LAN - WLAN). Zarówno sieci standardu IEEE 802.11, jak i ETSI HIPERLAN/2, są postrzegane jako istotne elementy systemów łączności bezprzewodowej czwartej generacji (4G). Ze względu na ograniczoną szerokość pasma radiowego, w sieciach tych niebagatelną rolę zaczynają odgrywać mechanizmy dopasowujące jakość obsługi (QoS) do wymagań aplikacji...
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International Conference on Emerging Ubiquitous Systems and Pervasive Networks
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International Conference on Collaborative Computing: Networks, Applications and Worksharing
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IEEE International Workshop on Cellular Nanoscale Networks and Applications
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International Conference on Artificial Neural Networks and Genetic Algorithms
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International Conference on Analysis of Images, Social Networks and Texts
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IEEE International Symposium on Security in Networks and Distributed Systems
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International Work-Conference on Artificial and Natural Neural Networks
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International Conference on Mobile and Ubiquitous Systems: Networks and Services
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IEEE International Workshop on Neural Networks for Signal Processing
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Infrastruktura ładowania pojazdów elektrycznych
PublicationW artykule przedstawiono przegląd zagadnień z zakresu infrastruktury ładowania pojazdów elektrycznych. Przeanalizowano wpływ dużej liczby pojazdów EV na system elektroenergetyczny. W analizie uwzględniono zarówno wzrastające zapotrzebowanie na moc jak też na zapewnienie wysokiej jakości energii elektrycznej. Pokazano ideę wykorzystania pojazdów EV jako magazynów energii w systemie elektroenergetycznym. Zaprezentowano podstawowe...
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Numeryczna analiza hydrauliki toru kajakarstwa górskiego w Drzewicy
PublicationW artykule zaproponowano wykorzystanie do analizy hydrodynamiki toru kajakarstwa górskiego symulacji numerycznej, wykorzystującej dwuwymiarowe równania ruchu wody w warunkach przepływu szybkozmiennego. Rozwiązanie równań hydrodynamiki wykonano samodzielnie z zastosowaniem metody objętości skończonych. Jako przykład zastosowania zaproponowanej metody przedstawiono analizę przepływu wzdłuż istniejącego, poddanego modernizacji toru...
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Performance evaluation of IEEE 802.11 fast BSS transition algorithms
PublicationSimultation experiments are conducted to answer the questions if multimedia services can be properly supported in IEEE 802.11r networks. The authors prove that handover delay can be reduced to 22 ms in the average case.
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Deep learning based thermal image segmentation for laboratory animals tracking
PublicationAutomated systems for behaviour classification of laboratory animals are an attractive alternative to manual scoring. However, the proper animals separation and tracking, especially when they are in close contact, is the bottleneck of the behaviour analysis systems. In this paper, we propose a method for the segmentation of thermal images of laboratory rats that are in close contact during social behaviour tests. For this, we are...
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Numerical analysis of open channel steady gradually varied flow using the simplified saint-venant equations
PublicationFor one-dimensional open-channel flow modeling, the energy equation is usually used. There exist numerous approaches using the energy equation for open-channel flow computations, which resulted in the development of several very efficient methods for solving this problem applied to channel networks. However, the dynamic equation can be used for this purpose as well. This paper introduces a method for solving a system of non-linear...
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Neural Network Subgraphs Correlation with Trained Model Accuracy
PublicationNeural Architecture Search (NAS) is a computationally demanding process of finding optimal neural network architecture for a given task. Conceptually, NAS comprises applying a search strategy on a predefined search space accompanied by a performance evaluation method. The design of search space alone is expected to substantially impact NAS efficiency. We consider neural networks as graphs and find a correlation between the presence...
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On the Importance of Resilience Engineering for Networked Systems in a Changing World
PublicationResilience is featured increasingly often in the media, usually applied to society when faced, for example, with disasters such as flooding and the enormous challenges that the Covid-19 pandemic posed. There are now many resilience-related discussion groups worldwide, and some standards initiatives devoted in particular to city resilience. However, there is relatively little explicit interest in resilience engineering for communication...
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Research on Quality Requirements of Data Transmission Services in RSMAD
PublicationThe paper presents a results and analysis of research of the quality of service requirements (defined by the QoS attributes) for imaging data transmission services using Radio System for Monitoring and Acquisition of Data from Traffic Enforcement Cameras (in short RSMAD). The paper also presents and discusses results of test on the impact of the size of photos from traffic enforcement cameras on the average transmission time. These...
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Accuracy analysis of the RSSI BLE SensorTag signal for indoor localization purposes
PublicationIn this paper we describe possibility of use the RSSI signal (Radio Signal Strength Indication) from Texas Instruments SensorTag CC2650 for indoor positioning purposes. This idea is not a new but in our opinion it is possible to use SensorTags with Bluetooth LE wireless interface for positioning inside buildings in such applications as people findings in hospitals, senior come care, etc. RSSI is mostly selected as the sensor localization...
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Remote current measurement with FPGA digital processing
PublicationThe work presents an implementation of a modular measurement and control systemthat controls variants of mains supply of 230V electrical equipment. The system allowsto supervise power consumption in the office electronic equipment. The system detectsthe instant of the reduced power consumption by a device and makes possible itsswitch-off in order to reduce energy cost. The current is measured with integratedcurrent/voltage converters....
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Data augmentation for improving deep learning in image classification problem
PublicationThese days deep learning is the fastest-growing field in the field of Machine Learning (ML) and Deep Neural Networks (DNN). Among many of DNN structures, the Convolutional Neural Networks (CNN) are currently the main tool used for the image analysis and classification purposes. Although great achievements and perspectives, deep neural networks and accompanying learning algorithms have some relevant challenges to tackle. In this...
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Application of Smart IoT Technology in Project Management Scenarios
PublicationThe report presents a low-cost and flexible solution to control and monitor home and industrial appliances. The popularity of automation devices has increased greatly in recent years due to higher affordability and simplicity through IoT phone and tablet connectivity. For this purpose, we have developed the IoT Outlet: a stand-alone communication unit, used to connect outlets to the internet. The IoT Plug is a power switch which...
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Lightweight glass and metal roof structures in the 19th century. Architecture and construction.
PublicationThe 19th century brought new construction possibilities. The usage of metal elements in mesh structures, filled in with glass, resulted in creating entirely new types of objects. They have distinguished themselves in architecture and technical solutions. The envelope structures giving spatial interiors were arising very quickly. They have been enabling large light penetration, triggering them extremely bright. Thus these building...
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Numerical Model of the Aortic Valve Implanted Within Real Human Aorta
PublicationCardiovascular system diseases are the main cause of deaths in developed and developing countries. The main reasons are myocardial infarction, heart failure, stroke and valvular diseases. These are caused mainly by arteriosclerosis. The valvular diseases involve a significant burden for the health care system and their frequency is rising with the patient age. This work describes the tools and numerical models appropriate for modeling...
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Bounds on isolated scattering number
PublicationThe isolated scattering number is a parameter that measures the vulnerability of networks. This measure is bounded by formulas de- pending on the independence number. We present new bounds on the isolated scattering number that can be calculated in polynomial time.
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Bounds on isolated scattering number
PublicationThe isolated scattering number is a parameter that measures the vulnerability of networks. This measure is bounded by formulas de- pending on the independence number. We present new bounds on the isolated scattering number that can be calculated in polynomial time.
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Machine Learning Applied to Aspirated and Non-Aspirated Allophone Classification—An Approach Based on Audio "Fingerprinting"
PublicationThe purpose of this study is to involve both Convolutional Neural Networks and a typical learning algorithm in the allophone classification process. A list of words including aspirated and non-aspirated allophones pronounced by native and non-native English speakers is recorded and then edited and analyzed. Allophones extracted from English speakers’ recordings are presented in the form of two-dimensional spectrogram images and...
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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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Experience-Based Cognition for Driving Behavioral Fingerprint Extraction
PublicationABSTRACT With the rapid progress of information technologies, cars have been made increasingly intelligent. This allows cars to act as cognitive agents, i.e., to acquire knowledge and understanding of the driving habits and behavioral characteristics of drivers (i.e., driving behavioral fingerprint) through experience. Such knowledge can be then reused to facilitate the interaction between a car and its driver, and to develop better and...