No. 3 (2015)
Published:
2015-09-30
ARTICLES FROM THIS ISSUE
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A High Capacity Energy Efficient Approach for Traffic Transmission in Cellular Networks
Abstract
The efficiency of cellular networks can be improved in various aspects such as energy consumption, network capacity and interference between neighboring cells. This paper proposes a high capacity energy efficient scheme (HCEE) for data transmission in cellular networks in a country area. In this paper, the authors obtain a new equation to characterize the minimal required output power for traffic transmission between a base station (BS) and a mobile user (MU) based on the MU distance from the BS. Also, the cells boundaries (the boundary of overlapping areas of neighboring cells) by two static and dynamic approaches are specified. This work helps for better frequency allocation to MUs and allows increasing network capacity. In this paper, the analytical modeling in order to formulate the HCEE algorithm and evaluate its performance is used. The performance evaluation results show the simplicity of the HCEE algorithm and its effect on energy consumption decline, network capacity enhancement and the interference reduction.
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A Survey on Wireless Network Applications in Automated Public Utilities Control and Management
Abstract
Public utilities such as water, electricity and gas are essential services that play a vital role in economic and social development. Automation of public utility services addresses the huge losses faced by the utility services today, due to non-accounting of distributed utility resources. Automation improves government revenues. The different type of architectures are proposed and designed for automated metering, control and management of public utilities like water, gas, and electricity for effective management and control of resources. The various network topologies, hardware and software architectures to automation and management of public utilities are proposed by researchers. In this paper, the different technologies proposed by various researchers across the globe are surveyed and list of issues and challenges for automated meter reading and control of public utilities is identified.
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Comparison of Wavelet Decomposition Coefficients Transmission Systems Using Splines and Classical Types of Modulation
Abstract
Wavelets are becoming increasingly used as a tool for the analysis of non-stationary data. To transmit the coefficients resulting from the signal decomposition traditionally their combination into a single data packet is used, without including unequal energy contribution of each factor and impact of the decomposition level. This paper analyzes (at different transmission speeds) the signals properties produced by classical modulation methods and spline modulation for wavelet coefficients transmission proposed by the author. For all signal types the additive Gaussian noise is used as a noise disturbance.
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Iterative Algorithm for Threshold Calculation in the Problem of Routing Fixed Size Jobs to Two Parallel Servers
Abstract
At present, solutions of many practical problems require significant computational resources and systems (grids, clouds, clusters etc.), which provide appropriate means are constantly evolving. The capability of the systems to fulfil quality of service requirements pose new challenges for the developers. One of the well-known approaches to increase system performance is the use of optimal scheduling (dispatching) policies. In this paper the special case of the general problem of finding optimal allocation policy in the heterogeneous n-server system processing fixed size jobs is considered. There are two servers working independently at constant but different speeds. Each of them has a dedicated queue (of infinite capacity) in front of it. Jobs of equal size arrive at the system. Inter-arrival times are i.i.d. random variables with general distribution with finite mean. Each job upon arrival must be immediately dispatched to one of the two queues wherefrom it will be served in FCFS manner (no pre-emption). The objective is the minimization of mean job sojourn time in the system. It is known that under this objective the optimal policy is of threshold type. The authors propose scalable fast iterative non-simulation algorithm for approximate calculation of the policy parameter (threshold). Numerical results are given.
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Performance Evaluation of Cognitive Radio Network Based on 2-D Markov Chain
Abstract
The objective of cognitive radio network is to enhance the wireless network spectrum utilization. In such a network, two types of users are enlisted, namely primary user (PU) and secondary user (SU). The PU can access any channel in case of its availability, but SU users have lower priority and can access a channel only when it is unused by PUs. The performance of such a network solely depends on two traffic parameters: probability of false alarm and probability of misdetection. In this paper the performance of such a network is analyzed based on two dimensional Markov chain including those parameters. The main contribution of this paper is to evaluate blocking probability and PU and SU throughput using the state transition chain instead of existing statistical analysis.
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Multi-layered Bayesian Neural Networks for Simulation and Prediction Stress-Strain Time Series
Abstract
The aim of the paper is to investigate the differences as far as the numerical accuracy is concerned between feedforward layered Artificial Neural Networks (ANN) learned by means of Kalman filtering (KF) and ANN learned by means of the evidence procedure for Bayesian technique. The stressstrain experimental time series for concrete hysteresis loops obtained by the experiment of cyclic loading is presented as considered example.
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The Analysis of OpenStack Cloud Computing Platform: Features and Performance
Abstract
Over 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.
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The Use of Genetic Algorithms for Searching Parameter Space in Gaussian Process Modeling
Abstract
The aim of the paper is to present the possibilities of modeling the experimental data by Gaussian processes. Genetic algorithms are used for finding the Gaussian process parameters. Comparison of data modeling accuracy is made according to neural networks learned by Kalman filtering. Concrete hysteresis loops obtained by the experiment of cyclic loading are considered as the real data time series.
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A k-Nearest Neighbors Method for Classifying User Sessions in E-Commerce Scenario
Abstract
This paper addresses the problem of classification of user sessions in an online store into two classes: buying sessions (during which a purchase confirmation occurs) and browsing sessions. As interactions connected with a purchase confirmation are typically completed at the end of user sessions, some information describing active sessions may be observed and used to assess the probability of making a purchase. The authors formulate the problem of predicting buying sessions in a Web store as a supervised classification problem where there are two target classes, connected with the fact of finalizing a purchase transaction in session or not, and a feature vector containing some variables describing user sessions. The presented approach uses the k-Nearest Neighbors (k-NN) classification. Based on historical data obtained from online bookstore log files a k-NN classifier was built and its efficiency was verified for different neighborhood sizes. A 11-NN classifier was the most effective both in terms of buying session predictions and overall predictions, achieving sensitivity of 87.5% and accuracy of 99.85%.
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Historical Perspectives of Development of Antique Analog Telephone Systems
Abstract
Long distance voice communication has been always of great interest to human beings. His untiring efforts and intuition from many years together was responsible for making it to happen to a such advanced stage today. This paper describes the development time line of antique telephone systems, which starts from the year 1854 and begins with the very early effort of Antonio Meucci and Alexander Graham Bell and ends up to the telephone systems just before digitization of entire telecommunication systems. The progress of development of entire antique telephone systems is highlighted in this paper. The coverage is limited to only analog voice communication in a narrow band related to human voice.
