Volume 6, Issue 3, March 2015

Contribution to the Defragmentation of the Frequency Spectrum of Elastic Optical Networks by Using Independent Sets in a Graph
Pages: 1-6 (6) | [Full Text] PDF (477K)
KAMAGATE Beman Hamidja, BABRI Michel and OUMTANAGA Souleymane
Ecole Doctorale Polytechnique de l'Institut Nationale Polytechnique Félix Houphouët Boigny (EDP- INPHB), Côte D'ivoire/ Laboratoire de Mathématiques et des Nouvelles Technologies de l´Information
Laboratoire de Recherche en Informatique et Télécommunication

Abstract - This paper is about spectrum defragmentation in elastic optical network. Our proposal consists in creating independents sets with current connections in the network, so that they can easily be rerouted or reallocated to another position of frequency slots in the optical spectrum. We choose to reroute as much as possible connections to lowest slots indices in order to free more contiguous and continuous slots in the highest areas indices for future connections. In addition, we define a parameter for judging the need for the defragmentation operation. The simulation performed with Matlab has allowed us to observe a reduction in the rejection rate of connections in the order of 6% after defragmentation, especially for those with wide bandwidth.
 Index Terms - Elastic Optical Network, Fragmentation, Defragmentation, Frequency Slots and OFDM
A Novel Video Compression Scheme Based on Fast Curvelet Transform
Pages: 7-10 (4) | [Full Text] PDF (541K)
Ahmed M. Elmolla, Gouda I. Salama and Ashraf D. Elbayoumy
The Egyptian Armed Forces, Cairo, Egypt-11331

Abstract - This paper describes a method for video compression using a new technique: combining fast curvelet transform with both run length and Huffman encoding. By adjust the number of element in each matrix in the output of fast curvelet transform then applying Run length and Huffman encoding. Run length codec is suited for compressing any type of data regardless of its information content. Huffman coding the principle is to use a lower number of bits to encode the data that occurs more frequently. This technique works fairly well for grayscale as well as color videos.
 Index Terms - Video Compression, Curvelet Transform, Run Length Codec, Huffman Coding, SSIM and PSNR
Insuring Halal Food Interlocking Institutional Worlds Integrity Using an Ontology Server
Pages: 11-17 (7) | [Full Text] PDF (332K)
Abdelrahman Abbas Ibrahim, Robert M. Colomb and Abdelgaffar Hamid Ahmed
Software Engineering Dept., Faculty of Computer Science, Sudan University of Science and Technology
School of IT & Electrical Engineering, The University of Queensland, Queensland, Australia
Faculty of Computer Science, Sudan University of Science and Technology

Abstract - Ontology servers are used to manage ontologies; is an information system that provides a number of functionalities during design, commit, and run time. Ontologies are widely used to overcome the problem of interoperability and assist in simplify interoperability among participants. Interlocking institutional worlds (IWS) are a collection of organizations interact together in order to achieve some business goals. Ontologies are consisting of two types of entities, the first for describing data of specific domain (classes, subclasses, Attributes etc), and the second for describing actions that will take place within an specific domain and resulting in changing the first one status. To insure that all (Actions) transactions within the IWs are valid and done in legal way, all transactions must be recorded and make it available for all participants, but current ontology case tools do not nearly provide representation of Instances of these transactions. Furthermore, both endurants and perdurants of the ontology need to be managed in order to be stored, retrieved and inferred. This paper is reporting on this problem using Halal Food supply Chain as an instance of IWs.
 Index Terms - Perdurant Ontology, Information Systems Interoperability, Interlocking Institutional Worlds and Ontology Server
Performance Analysis of PAPR Reduction Techniques Using PTS and SLM in OFDM System
Pages: 18-22 (5) | [Full Text] PDF (392K)
J. P. Panwar and Y.K.Jain
Department of Technical Education, Haryana, India
Mewar University, Rajasthan, India

Abstract - One of the challenging issues for Orthogonal Frequency Division Multiplexing (OFDM) system is its high Peak-to-Average Power Ratio (PAPR). As we are using the linear power amplifier at the transmitter side so it’s operating point will go to the saturation region due to the high PAPR which leads to out-band radiation and in-band distortion. This can be avoided with increasing the dynamic range of power amplifier which leads to high cost and high consumption of power at the base station. In this paper we mainly focus on Partial Transmit Sequence (PTS) and Selected Mapping (SLM) method. A simulation result shows the comparison of these methods. SLM and PTS reduce PAPR about 5.6dB and 4.2dB respectively.
 Index Terms - Orthogonal Frequency Division Multiplexing (OFDM), Complementary Cumulative Distribution Function (CCDF), Peak-to-Average Power Ratio (PAPR), Partial Transmit Sequence (PTS) and Selected Mapping (SLM)
GRPS: Greedy Routing Predictive Score Base in VANET
Pages: 23-27 (5) | [Full Text] PDF (572K)
Mohammad Yosefzadeh, Reza Rafeh and Ramin Karimi
Department of computer engineering, Malayer Branch, Islamic Azad University, Malayer, Iran
Department of computer engineering, Malard Branch, Islamic Azad University, Tehran, Iran

Abstract - Vehicular Ad-Hoc Networks are highly mobile wireless ad hoc networks. Routing of data in VANETs is a challenging task due to rapidly changing topology and high speed mobility of vehicles. Considering the fact that vehicles often have predicable mobility, we propose GRPS (Greedy Routing Predictive Score Base) to forward packet to the most suitable next hop based on both current and predicable future situations. We evaluate the performance of the solutions via simulations in highway and urban senarioes. Simulation results show that our solutions outperform existing ones in terms of packet delivery ratio, end-to-end delay.
 Index Terms - Vehicular Ad-Hoc Networks, Mobility and Predictive

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