Institute of Electron Technology
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Performance Comparison of Homogeneous and Heterogeneous 3D Wireless Sensor Networks, Journal of Telecommunications and Information Technology, 2017, nr 2
Get PDFRecent developments in wireless sensor networks include their applications in safety, medical monitoring, environment monitoring and many more. Limited battery energy and efficient data delivery are most considered constraints for sensor nodes. Depletion of node battery ceases functioning of the node. The network lifetime can be enhanced with the help of Multi-Layer protocol (ML-MAC). This paper presents a practical approach including 3-dimensional deployment of sensor nodes and analyzes two different types of networks – homogeneous and heterogeneous WSNs. To analyze various QoS parameters, two types of nodes are considered in a heterogeneous network. The performance of both the networks is compared through simulations. The results show that ML-MAC performs better for a 3D heterogeneous WSNs
Parallel Mutant Execution Techniques in Mutation Testing Process for Simulink Models, Journal of Telecommunications and Information Technology, 2017, nr 4
Get PDFMutation testing – a fault-based technique for software testing – is a computationally expensive approach. One of the powerful methods to improve the performance of mutation without reducing effectiveness is to employ parallel processing, where mutants and tests are executed in parallel. This approach reduces the total time needed to accomplish the mutation analysis. This paper proposes three strategies for parallel execution of mutants on multicore machines using the Parallel Computing Toolbox (PCT) with the Matlab Distributed Computing Server. It aims to demonstrate that the computationally intensive software testing schemes, such as mutation, can be facilitated by using parallel processing. The experiments were carried out on eight different Simulink models. The results represented the efficiency of the proposed approaches in terms of execution time during the testing process
Monte Carlo Tree Search Algorithm for the Euclidean Steiner Tree Problem, Journal of Telecommunications and Information Technology, 2017, nr 4
Get PDFThis study is concerned with a novel Monte Carlo Tree Search algorithm for the problem of minimal Euclidean Steiner tree on a plane. Given p p p points (terminals) on a plane, the goal is to find a connection between all the points, so that the total sum of the lengths of edges is as low as possible, while an addition of extra points (Steiner points) is allowed. Finding the minimum Steiner tree is known to be np-hard. While exact algorithms exist for this problem in 2D, their efficiency decreases when the number of terminals grows. A novel algorithm based on Upper Confidence Bound for Trees is proposed. It is adapted to the specific characteristics of Steiner trees. A simple heuristic for fast generation of feasible solutions based on Fermat points is proposed together with a correction procedure. By combing Monte Carlo Tree Search and the proposed heuristics, the proposed algorithm is shown to work better than both the greedy heuristic and pure Monte Carlo simulations. Results of numerical experiments for randomly generated and benchmark library problems (from OR-Lib) are presented and discussed
Improving the GPR Detectability Using a Novel Loop Bowtie Antenna, Journal of Telecommunications and Information Technology, 2017, nr 3
Get PDFThe Ground Penetrating Radar (GPR) technique finds immense applications in civil engineering today, as the most suitable approach for non-destructive testing of pavements, highways, concrete structures, and more. The major challenge in carrying out a GPR evaluation is that the properties of the probed medium are usually unknown. The permittivity and conductivity of the medium may vary from those of air to water. The electromagnetic waves also have a frequency dependent attenuation. The ability of GPR to detect signals reflected and scattered by the targets largely depends upon the antenna performance. This paper studies a novel 11:1 wideband loop bowtie antenna with very good radiation properties in the entire operating bandwidth. Synthetic and experimental results are presented for the return loss and gain of the antenna. Furthermore, experimental results are presented for the radiation patterns in the E- and H-plane. We also used the antenna to measure B-scans over two different pipes, a bamboo, and a reinforced concrete structure. All results obtained with the proposed antenna have been compared with results obtained by using a RC loaded antenna. It has been found that the loop bowtie antenna has excellent detection capability and produces less clutter. The loop loading technique can be applied to existing antennas for improved GPR imaging. This will improve the detectability of GPR by improving the target return signal
Relay-assisted WDM-FSO System: A Better Solution for Communication under Rain and Haze Weather Conditions, Journal of Telecommunications and Information Technology, 2017, nr 4
Get PDFAmong various conventional wireless communication systems, Free Space Optics (FSO) may be distinguished as well, which provides a good level security, high data rates, an enormous bandwidth and negligible susceptibility to electromagnetic interference. The main problem arises with unfavorable weather conditions, which affect the system’s parameters and require an aversion to other paths. The weather conditions discussed are rain and haze. Elimination of their adverse effects is essential for establishing a better communication system. The routing path is a major issue, as its decreased parameters lead to the diversion of the transmitted signal or to its total loss. In this article, increased system path length and proficiency levels are demonstrated by using relays, which are assisted by Wavelength Division Multiplexing (WDM)
A Cloud-aided Group RSA Scheme in Java 8 Environment and OpenStack Software, Journal of Telecommunications and Information Technology, 2016, nr 2
Get PDFIn this paper a RSA based security system enabling the group of users to upload the single masked message to the cloud environment is proposed. Data stored are encrypted using RSA algorithm. The data receiver is able to encrypt the message retrieved from the cloud environment using private key. Two different separate RSA systems are used. The presented approach is divided into three parts. First, an RSA key is generated for each sender. Then masking the message by newly chosen mask proposed individually by every member, additionally encrypted by individual RSA private key of each member is proceed. Next, encrypting the gathered message inside the cloud environment, using the public key of the receiver is executed. In the third step, the message is decrypted by the receiver using his private RSA key. The scheme reduces the computational load on users side and transfers calculations and storage effort to the cloud environment. The proposed algorithm was developed for storing and sending the data that originally are produced by a group of users, but the receiver of the data is single. It was implemented using Java 8 and OpenStack software. Numerical test of different key length for RSA are presented
Application of Social Network Inferred Data to Churn Modeling in Telecoms, Journal of Telecommunications and Information Technology, 2016, nr 2
Get PDFThe subject of this work is the use of social network analysis to increase the effectiveness of methods used to predict churn of telephony network subscribers. The social network is created on the basis of operational data (CDR records). The result of the analysis is customer segmentation and additional predictor variables. Proposed hybrid predictor employs set of regression models tuned to specific customer segments. The verification was performed on data obtained from one of the Polish operators
Stackelberg Security Games: Models, Applications and Computational Aspects, Journal of Telecommunications and Information Technology, 2016, nr 3
Get PDFStackelberg games are non-symmetric games where one player or specified group of players have the privilege position and make decision before the other players. Such games are used in telecommunication and computational systems for supporting administrative decisions. Recently Stackleberg games became useful also in the systems where security issues are the crucial decision criteria. In this paper authors briefly survey the most popular Stackelberg security game models and provide the analysis of the model properties illustrated in the realistic use cases
A Practical Approach to Trac Engineering using an Unsplittable Multicommodity Flow Problem with QoS Constraints, Journal of Telecommunications and Information Technology, 2016, nr 3
Get PDFThe paper presents a practical approach to calculating intra-domain paths within a domain of a content-aware network (CAN) that uses source routing. This approach was used in the prototype CAN constructed as a part of the Future Internet Engineering project outcome. The calculated paths must satisfy demands for capacity (capacity for a single connection and for aggregate connections using the given path are considered distinctly) and for a number of path-additive measures like delay, loss ratio. We state a suitable variant of QoS-aware unsplittable multicommodity ow problem and present the solving algorithm. The algorithm answers to the needs of its immediate application in the constructed system: a quick return within a short and fairly predictable time, simplicity and modi ability, good behavior in the absence of a feasible solution (returning approximately-feasible solutions, showing how to modify demands to retain feasibility). On the other hand, a certain level of overdimensioning of the network is explored, unlike in a typical optimization algorithm. The algorithm is a mixture of: (i) shortest path techniques, (ii) simpli ed reference-level multicriteria techniques and parametric analysis applied to aggregate the QoS criteria (iii) penalty and mutation techniques to handle the common constraints. Numerical experiments assessing various aspects of the algorithm behavior are given
Digital Audio Broadcasting or Webcasting: A Network Quality Perspective, Journal of Telecommunications and Information Technology, 2016, nr 1
Get PDFIn recent years, many alternative technologies of delivering audio content have emerged, with different advantages and disadvantages. In this paper pros and cons of digital audio broadcasting and webcasting transmission techniques in a network quality perspective are described. A case study of user expectations with respect to currently available services is analyzed, and the perceived quality of real digital broadcasted and webcasted radio stations is examined