International Journal of Computers and Communications

E-ISSN: 2074-1294
Volume 9, 2015

Notice: As of 2014 and for the forthcoming years, the publication frequency/periodicity of NAUN Journals is adapted to the 'continuously updated' model. What this means is that instead of being seperated into issues, new papers will be added on a continuous basis, allowing a more regular flow and shorter publication times. The papers will appear in reverse order, therefore the most recent one will be on top.

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Volume 9, 2015 

Title of the Paper: Towards an Algorithm for Efficient Use of Social Network Resources by Using Web Scraping Techniques


Authors: Valon Xhafa, Blerim Rexha, Korab Rrmoku

Pages: 100-104

Abstract: The rapid growth of Web in recent years has changed everyday life. New applications for sharing social activities on the Web, such us Facebook, Twitter, Google+ etc. are becoming more and more popular. The interactivity and behavior among these users in Web is measured by number of likes, comments, posts and shares and their personal perception. But these new social applications have their limits and constraints regarding the usage of their networks resources. This paper presents an algorithm for efficient use of these resources and overcoming these limits. The algorithm is set as outcome of the survey conducted among community members. For better performance, the combined approach using the Web scraping techniques and reverse image search was used.

Title of the Paper: Robot Path Planning Algorithm


Authors: Velko Naumov, Milena Karova, Danislav Zhelyazkov, Mariana Todorova, Ivaylo Penev, Ventsislav Nikolov, Vilian Petkov

Pages: 96-99

Abstract: This paper presents an improvement of a classic Dijkstra algorithm to the domain of sampling based motion. The algorithm uses an image, obtained by a camera. The algorithm processes the image to convert it into a matrix, presenting the labyrinth with obstacles and walls. Afterwards the algorithm finds the shortest path to a final target in the labyrinth. In contrast to the classical Dijkstra’s algorithm, the presented algorithm compares the size of the robot to the size of the obstacles on the way. A simulation of the algorithm is developed to visualize the movement of the robot. Experimental results, obtained by the simulation, are presented. The potential of the proposed results is apparent both in terms of reliability and quality of solutions found.

Title of the Paper: Energy Efficient Multi-Hops Clustering Protocol for Wireless Sensor Networks


Authors: Saad Harous, Zibouda Aliouat

Pages: 88-95

Abstract: Wireless Sensor Networks (WSNs) are been used in many applications such as: health care monitoring, environmental/Earth sensing, industrial monitoring, data logging. But in order to reach their potential, researchers must find solution to some difficulties which are slowing down the wide spread use of these networks. These difficulties are inherent to their constrained specificities which require adapted solutions unrelated to classical wire networks. The number of packets sent/received by WSN has a huge impact on the amount of energy consumed. In order to reduce this number and to ensure at the same time WSN successful operation, hierarchical clustering protocols have been developed. In this paper, we present Well Balanced TEEN (WB-TEEN) and Well Balanced with Multi-hops intra-cluster TEEN (WBM-TEEN): two hierarchical routing protocols, based on nodes clustering and improving the well-known protocol Threshold sensitive Energy Efficient sensor Network protocol (TEEN). This improvement is accomplished in a way such that the number of nodes in each cluster is balanced and the total energy consumption between sensor nodes and cluster heads is minimized by using multi-hops intra-cluster communication. Simulation results (using NS2 simulator) show that the proposed protocols exhibit better performance than Low Energy Adaptive Clustering Hierarchy (LEACH) and TEEN in terms of energy consumption and network lifetime prolongation.

Title of the Paper: An Approach Based on Ontologies and Multi-Agent Systems to Hide Heterogeneity: Application to Port Information System


Authors: Mehdi Abid, Benayad Nsiri, Yassine Serhane

Pages: 82-87

Abstract: Nowadays everyone is conscious of the technology’s evolution that plays a key role in the development of information technology. The optimization of this complex system is based on a collaborative sharing of information and knowledge between each port inf

Title of the Paper: Computational Intelligence in Portfolio Optimization – the IPSOS Model


Authors: Loukeris N., Eleftheriadis I.

Pages: 76-81

Abstract: Although returns distributions are complex, they can’t avoid manipulation in any form. We propose a new methodology, the Intelligent Portfolio Selection & Optimisation System – IPSOS that takes into account hidden information within the extended accounting data and financial statements, among other values incorporates them on a new Jordan Elman hybrid network to provide safer financial evaluations.

Title of the Paper: Utilization of the Finnish National Security Auditing Criteria “KATAKRI” in the EU FP7 PERSEUS Project


Authors: Jyri Rajamäki

Pages: 68-75

Abstract: Protection of European borders and Seas through the Intelligent Use of Surveillance (PERSEUS) is an FP7 demonstration project supported by the FP7 Security Research theme under DG-Enterprise. Its purpose is to build and demonstrate an EU maritime surveillance system integrating existing national and communitarian installations and enhancing them with innovative technologies. When connecting together surveillance systems of two or more organizations, the trust for others and their cyber security is the main issue. Security audit is a way to demonstrate an organization’s security level. This multiple case study analysis consists of six individual case studies that research how the Finnish national security auditing criteria KATAKRI is suitable for different types of organizations when they are developing their security levels. The cross-case conclusions investigate, how KATAKRI could be applied when developing information security policies of different organizations in the perspective of information sharing. The results revealed that KATAKRI is a useful tool for developing organizations’ security policies. However, KATAKRI should be redeveloped towards a tool that encourages and simplifies information sharing instead of being a burden.

Title of the Paper: Comparison of Cryptographic Methods Triple DES, AES and a Method Based on the Arithmetic of Elliptic Curves (ECC) on the Android Mobile Platform


Authors: Milan Oulehla, David Malaník

Pages: 62-67

Abstract: The paper presents a comparison of three cryptographic methods on mobile devices with the Android operating system. Specifically, methods compared were these: cryptographic method based on the arithmetic of elliptic curves, Triples DES and AES. They were chosen because they seemed to be most appropriate due to the limited processing power of today’s mobile devices. For comparison purposes of cryptographic methods, a special cryptographic benchmark was created on the Android platform. Overall, 6660 test files were encrypted. The testing was performed on actual hardware, because tests carried out on an emulator might be misleading. The results were then processed using regression analysis. The tests have shown that the most appropriate cryptographic method for the Android platform is AES with 256-bit key.

Title of the Paper: Impossible Differential Attacks on 4 Round DES-Like Ciphers


Authors: Pavol Zajac

Pages: 56-61

Abstract: Data Encryption Standard was a main public encryption standard for more than 20 years, but now it is considered insecure. However, there are still numerous proposals of new lightweight cipher designs similar to DES, some of them only consisting of 4 Feistel rounds. It is known that there exist generic distinguishers for 4-round Feistel cipher, but their complexity scales exponentially with the cipher size. In the theoretical analysis, an ideal round function is considered. In this article we focus on a model of Feistel ciphers with design similar to DES. The round function consists of bit expansion, S-box application, and permutation of bits. We show that practical DES-like designs cannot have only 4-rounds, even if the S-boxes are key-dependent, due to the impossible differential attacks.

Title of the Paper: Next Generation Web - Intelligent Search, Question Answering, Summarization and More


Authors: Emdad Khan

Pages: 44-55

Abstract: Wouldn't it be nice to say or type "show me all the pictures from last Saturday party" on a browser and get all the requested pictures from Facebook? Or do specific transaction like "I would like to buy the following book - Artificial Intelligence by Stuart Russel, 3rd edition; please use my credit card on file and ship it to my home address (assuming that the user is already logged on to the specific website)" and receive the requested book on time? Or ask a question and get a specific answer? Or get summary of an article? Or get a much better prediction from a BI (Business Intelligence) or Analytics software? In fact, based on good research, we see a clear trend that the future Internet will be something that can provide very specific, more precise and direct information (like the examples mentioned above) in a very easy way so that anyone including an illiterate person can access and use it at ease. We call this Intelligent Internet (IINT). Existing search engines usually provide thousands to millions of search results for any typical search. It is not easy even for advanced users to find the desired results from such a large set. One cannot get a specific answer or a set of answers to a question typed in a search engine. There is no automated way to get a good summary of a document or get a good inference from a document. Similarly, there is no way to get some specific desired information like "basic information of last 3 flights I took on United Airlines". However, as mentioned, these are the key features that users would expect from next generation internet. Moreover, users would like to use such features in a natural way - like using a natural language sentence (by typing or preferably, by saying it; and for many cases using sentences that may not be grammatically correct). This is obviously a very complex task (and hence not solved yet). We would need multiple approaches, algorithms and technologies to achieve these. For example, Natural Language understanding (NLU), Big Data and Intelligent Agent (IA) are the 3 key areas we need to focus on. A Semantic Engine is the core engine that is needed for all these 3 major areas. In this paper we describe how a Semantic Engine using Brain-Like Approach (SEBLA) can address all key complexities of the next generation Internet and effectively provide all the key desired features mentioned above. We focus on Intelligent Search, Question Answering (Q & A System) and Summarization. We also show how NLU, IA and Big Data can be integrated with existing client-server based web application architecture using the design patterns (e.g. Model-View-Controller) and software frameworks (e.g. Java or Ruby-on-Rails).

Title of the Paper: An Efficient Multi-Stages Algorithm for the Determination of Communication Network Reliability


Authors: Musaria K. Mahmood, Fawzi M. Al-Naima, Lujain S. Abdulla

Pages: 36-43

Abstract: A new method for calculating network reliability is presented in this paper. This method allows the analysis of complex communication networks by the use of multistage algorithm based on the hybrid combination of reduction technique and tie set methods. The algorithm begins with the application of reduction technique to simplify the network topology by elimination all series and parallel connection of communication links. The second stage is the application of an algorithm consisting of finding all tie-sets of the reduced network. The simplifications of the network in the first stage will affect positively the number and the complexity of tie sets, keeping the final result of the network reliability unchanged. Links probabilities are used to generate the network topologies with imperfect communication nodes, and bidirectional links which will yield to a more general situation. Algorithms and calculation are executed on MATLAB, where all the above assumptions are taken into account.

Title of the Paper: A Solution for Applying IEC 61499 Function Blocks in the Development of Substation Automation Systems


Authors: Valentin Vlad, Cezar D. Popa, Corneliu O. Turcu, Corneliu Buzduga

Pages: 30-35

Abstract: This paper presents a solution for applying IEC 61499 function blocks along with IEC 61850 specifications in modeling and implementing control applications for substations automation. The IEC 61499 artifacts are used for structuring the control logic, while the IEC 61850 concepts for communication and information exchange between the automation devices. The proposed control architecture was implemented and validated in a simple fault protection scenario with simulated power equipment.

Title of the Paper: Orthogonal Chaotic Sequence for Use in Wireless Channels


Authors: Anamika Sarma, Kandarpa Kumar Sarma, Nikos Mastorakis

Pages: 21-29

Abstract: Chaotic sequences are effectively used for secure communication. Generation of chaotic sequences continues to be an evolving area. Recently, stress has been given to the generation of orthogonal chaotic codes.  In this paper, a chaotic spreading sequence based   direct sequence/spread spectrum (DSSS) communication system is proposed. Here, a logistic map is used for generation of chaotic sequences used as a spreading factor in a DSSS system in Rayleigh fading channel. We discuss a method to make the chaotic code orthogonal to mitigate several disadvantages of the channel. The paper also includes a detail explanation of all the experimental work done in order to use orthogonal chaotic code as a spreading factor in various channels and related results and discussion. The bit-error rate (BER) and symbol error rate (SER) of the proposed system is compared with Gold code. Results show that the proposed system has a significant improvement in BER and SER. The mutual information, autocorrelation function and computational time of the system are also analyzed.

Title of the Paper: Effect of Varying the Cyclic Prefix Length on OFDM System Performance over Different Wireless Channel Models


Authors: Amar A. Al-Jzari, Kostanic Ivica

Pages: 14-20

Abstract: Cyclic Prefix (CP) is a significant feature of an OFDM waveform. It is used to completely eliminate both Inter-Symbol Interference (ISI) and Inter-Carrier Interference (ICI) as long as the CP length is greater than the channel delay spread. By eliminating the ISI and ICI, the CP compensates for the effect of the multi-path dispersion; but it consumes a considerable amount of the scarce spectrum and the power. Conventional OFDM uses a fixed and large CP length to tolerate worst case channel condition. This technique, however, causes a loss in bandwidth efficiency as well as consumes relatively more transmitter energy. Therefore, there is a need to adopt the CP length according to instantaneous channel parameters. In this paper, we study the effect of varying the CP length on the OFDM system performance over different channel models, where the variable CP length is estimated based on the RMS delay spread of the channel. According to this method, the estimated CP length optimizes the system capacity and improves the overall system performance.

Title of the Paper: System Dynamics Modelling to Study the Diffusion of a Supply Chain Management Mobile Application


Authors: Anna C. Cagliano, Alberto De Marco, Carlo Rafele

Pages: 1-13

Abstract: The local fresh food supply chain is experiencing market fragmentation and little coordination among suppliers and customers, which demand for integrated management by means of a timely information exchange connecting all the supply chain echelons and enabling efficient logistics activities. Mobile communication technologies can support the achievement of such goals because of their large diffusion and ability to ensure real time information updates. In this context, a System Dynamics model is developed to study the diffusion pattern and the associated operational and economic impacts of a new application for mobile devices assisting supply chain operations. A fresh food supply chain in Northern Italy has been considered. The base application and the integration of three additional features allowing the management of product traceability, electronic payments, and time-sensitive deliveries are investigated. Simulation results provide an understanding of the mechanisms of adoption of the mobile services and help define business policies to disseminate their diffusion.