Institute of Electron Technology
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2189 research outputs found
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Focusing Operators and Tracking Moving Wideband Sources , Journal of Telecommunications and Information Technology, 2016, nr 4
Get PDFIn this paper, the localization of wideband source with an algorithm to track a moving source is investigated. To locate the wideband source, the estimation of two directions of arrival (DOA) of this source from two different arrays of sensors is used, and then, a recursive algorithm is applied to predict the moving source’s position. The DOA is estimated by coherent subspace methods, which use the focusing operators. Practical methods of the estimation of the coherent signal subspace are given and compared. Once the initial position is estimated, an algorithm of tracking the moving source is presented to predict its trajectory
Closed-form Distribution and Analysis of a Combined Nakagami-lognormal Shadowing and Unshadowing Fading Channel , Journal of Telecommunications and Information Technology, 2016, nr 4
Get PDFThe realistic wireless channels face combined (time shared) Nakagami-lognormal shadowing and unshadowing fading because of time varying nature of radio channel and mobile user. These channels can be modeled as time-shared sum of multipath-shadowing and unshadowing Rician distributions. These fading create severe problems in long distance wireless systems where multipath fading is superimposed on shadowing fading (called multipath-shadowing fading). The multipath effect can be modeled using Rayleigh, Rician, Nakagami-m or Weibull distribution and shadowing effect is modeled using lognormal distribution. In this paper, authors present a new closed-form probability distribution function of a Nakagami-lognormal fading channel. Using this result, the closed-form expression of combined Nakagamilognormal shadowing and unshadowing fading is presented. The obtained closed-form result facilitates to derive the important performance metrics of a communication system such as amount of fading, outage probability, and average channel capacity in closed-form expressions
Rozwój e-usług publicznych w Polsce na przykładzie projektów realizowanych przez administrację publiczną w ramach 7. osi POIG, Telekomunikacja i Techniki Informacyjne, 2016, nr 1-2
Get PDFArtykuł prezentuje rozwój e-usług publicznych w Polsce w latach 2010–2015. Szczególną uwagę zwrócono na znaczenie projektów realizowanych w ramach 7. osi Programu Operacyjnego Innowacyjna Gospodarka, które mają wspierać wzrost rozwoju e-usług publicznych w Polsce. Ponadto w artykule zwrócono uwagę na znaczenie projektu System Informacyjny o infrastrukturze szerokopasmowej i portal Polska Szerokopasmowa, którego systemy zapewniają wsparcie administracji rządowej w zarządzaniu oraz koordynacji projektów
Network Dimensioning with Maximum Revenue Efficiency for the Fairness Index, Journal of Telecommunications and Information Technology, 2016, nr 4
Get PDFNetwork dimensioning is a specific kind of the resource allocation problem. One of the tasks in the network optimization is to maximize the total flow on given pairs of nodes (so-called demands or paths between source and target). The task can be more complicated when different revenue/profit gained from each unit of traffic stream allocated on each demand is taken into account. When the total revenue is maximized the problem of starvation of less attractive paths can appear. Therefore, it is important to include some fairness criteria to preserve connections between all the demands on a given degree of quality, also for the least attractive paths. In this paper, a new bicriteria ratio optimization method which takes into account both, the revenue and the fairness is proposed. Mathematical model is built in a form of linear programming. The solutions are analyzed with some statistical measures to evaluate their quality, with respect to fairness and efficiency. In particular, the Gini’s coefficient is used for this purpose
Subjective Assessment for Standard Television Sequences and Videotoms - H.264/AVC Video Coding Standard, Journal of Telecommunications and Information Technology, 2015, nr 1
Get PDFThis paper presents comparison of videotoms and standard television sequences in terms of image distortions and perceived subjective quality a ected by H.264/AVC compression with changed bit rate. Results from initial tests, performed as laboratory exercise can be a reference to show scale of diversity in both level of degradation and Mean Opinion Score (MOS) evaluation. Results and comments included in this paper give overview on the codec influence on videotoms and can suggest approach for further tests and experiments
The Analysis of OpenStack Cloud Computing Platform: Features and Performance, Journal of Telecommunications and Information Technology, 2015, nr 3
Get PDFOver the decades the rapid development of broadly defined computer technologies, both software and hardware is observed. Unfortunately, software solutions are regularly behind in comparison to the hardware. On the other hand, the modern systems are characterized by a high demand for computing resources and the need for customization for the end users. As a result, the traditional way of system construction is too expensive, inflexible and it doesn’t have high resources utilization. Present article focuses on the problem of effective use of available physical and virtual resources based on the OpenStack cloud computing platform. A number of conducted experiments allowed to evaluate computing resources utility and to analyze performance depending on the allocated resources. Additionally, the paper includes structural and functional analysis of the OpenStack cloud platform
Analysis of Burst Ratio in Concatenated Channels, Journal of Telecommunications and Information Technology, 2015, nr 4
Get PDFBurst ratio is a parameter that quantifies packet loss patterns in transmission networks. It has been defined for an end-to-end scenario, therefore burst ratio can be determined only if the characteristics of the whole transmission path are known. In this paper, the burst ratio parameter applicability to cases when the transmission path consists of a series of transmission channels with known packet loss rate and burst ratio values is extended. The paper also presents the results of simulations performed with NS2 software, demonstrating the validity of the burst ratio analysis. Consequently, the research makes it possible to determine the value of the burst ratio parameter in concatenated packet networks, which in turn supports delivering higher quality VoIP services
Measured Interference of LTE Uplink Signals on DVB-T Channels, Journal of Telecommunications and Information Technology, 2015, nr 4
Get PDFBecause of the decision, taken during the ITU WRC-07, to allocate the upper part of the so-called digital dividend spectrum for mobile services on a co-primary basis with TV broadcast services, the involved stakeholders have a great interest in avoiding any interference caused by signals transmitted in adjacent bands. In this context the paper presents some experimental results of a study addressed to assess the effects produced by an interferential LTE signal transmitted from a user terminal when it is in proximity of a television antenna that receives DVB-T signals. The study has been conducted in the context of collaboration between Fondazione Ugo Bordoni and ISCTI, the scientific and technical body of the Italian Ministry of Economic Development, using high professional laboratory equipments and considering different experimental simulation test setups. Several simulation scenarios have been analyzed and results in terms of protection ratio and protection distance have been carried out
Supervised Kernel Principal Component Analysis by Most Expressive Feature Reordering, Journal of Telecommunications and Information Technology, 2015, nr 2
Get PDFThe presented paper is concerned with feature space derivation through feature selection. The selection is performed on results of kernel Principal Component Analysis (kPCA) of input data samples. Several criteria that drive feature selection process are introduced and their performance is assessed and compared against the reference approach, which is a combination of kPCA and most expressive feature reordering based on the Fisher linear discriminant criterion. It has been shown that some of the proposed modifications result in generating feature spaces with noticeably better (at the level of approximately 4%) class discrimination properties
Biometric Systems Based on Palm Vein Patterns, Journal of Telecommunications and Information Technology, 2015, nr 2
Get PDFThe work covers issues related to the design of biometric systems based on the hand vascular pattern. The study includes analysis of various stages of biometric systems design ranging from acquisition, feature extraction and biometric pattern creation for verification methods. The extraction methods based on two-dimensional density function and the extraction of the characteristic points { minutiae are presented. The article features the results of tests carried out on two different bases of blood vessels in a hand