Wednesday, 18 June 2008 02:36

NAMP: Neighbor Aware Multicast Routing Protocol for Mobile Ad Hoc Networks

Al-Sakib Pathan1, Muhammad Monowar2, Md. Rabbi3, Muhammad Alam1, and Choong Hong1

1 Department of Computer Engineering, Kyung Hee University, South Korea

2 Department of Computer Science and Engineering, University of Chittagong, Bangladesh

3 CSE Departments, Shahjalal University of Science and Technology, Bangladesh

Abstract: A Mobile Ad Hoc Network (MANET) represents a system of wireless mobile nodes that can freely and dynamically self-organize into arbitrary and temporary network topologies without the presence of any fixed communication infrastructure. Reliable routing and robustness of the network are two important issues for MANETs. In this paper we propose Neighbour Aware Multicast Routings Protocol (NAMP), which is a tree based, hybrid multicast routing protocol for ad hoc networks. Our routing protocol aims at achieving robustness in the ad hoc networks as well as the improvement of the end-to-end delivery of data packets. For route creation, the protocol uses neighboring information and dominant pruning approach. It uses secondary forwarder method for route maintenance.

Keywords: Ad hoc networks, dominant pruning, secondary forwarder list, multicasting, NAMP.

Received September 18, 2006; Accepted November 13, 2006

 

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Wednesday, 18 June 2008 02:34

Neural Networks and Support Vector Machines Classifiers for Writer Identification Using  Arabic Script 

Sami Gazzah1 and Najoua Ben Amara2

 1National School of Engineers of Sfax, Tunisia

2National School of Engineers of Sousse, Tunisia

Abstract: In this paper, we present an approach for writer identification carried out using off-line Arabic handwriting. Our proposed method is based on the combination of global and structural features. We used genetic algorithm for feature subset selection in order to eliminate the redundant and irrelevant ones. A comparative evaluation between two classifiers is done using Support Vector Machines and Multilayer Perceptron (MLP). The best results have been achieved using optimal feature subset and MLP with an average rate of 94%. Experiments have been carried out on a database of 120 text samples. The choice of the text samples was made to ensure the involvement of the various internal shapes and letter locations within a subword.

Keywords: Writer identification, off-line Arabic handwriting, genetic algorithm, support vector machines, multilayer perceptron.

Received June 16, 2006; accepted July 23, 2006

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Wednesday, 18 June 2008 02:32

Applying Genetic Algorithms for Searching Key-Space of Polyalphabetic Substitution Ciphers

Ragheb Toemeh1 and Subbanagounder Arumugam2

1Department of Computer Science and Engineering, Government College of Technology, India

2Directorate of Technical Education, India

Abstract: In this paper the Cryptanalysis of polyalphabetic by applying Genetic algorithm is presented. The applicability of Genetic algorithms for searching the key space of encryption scheme is studied. In Vigenere cipher, guessing the key size is done by applying Genetic Algorithm. The frequency analysis is used as an essential factor in objective function.

Keywords: Polyalphabetic cipher, Vigenere cipher, genetic algorithm.

Received May 27, 2006; Accepted August 5, 2006

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Wednesday, 18 June 2008 02:29

A New Exam Scheduling Algorithm Using Graph Coloring

Mohammad Malkawi1, Mohammad Al-Haj Hassan2, and Osama Al-Haj Hassan3

1SUN Microsystems, Network Circle, USA

2Faculty of IT, Middle East University for Graduate Studies, Jordan

3Department of Computer Science, University of Georgia, USA

 

Abstract: This paper presents a graph-coloring-based algorithm for the exam scheduling application, with the objective of achieving fairness, accuracy, and optimal exam time period. Through the work, we consider few assumptions and constraints, closely related to the general exam scheduling problem, and mainly driven from accumulated experience at various universities. The performance of the algorithm is also a major concern of this paper.

Keywords: Exam scheduling, graph algorithms, graph coloring, performance analysis.

Received May 23, 2006; Accepted September 18, 2006

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Wednesday, 18 June 2008 02:28

Diagnosis of Distillation Column Problems Using New Generation Gamma-Ray Scanning Gauge

Khalid Laraki1, Rachad Alami1, Rajaa El Morsli2, Abdessalam Bensitel1, Lhachemi El Badri1, and El-Mehdi Hamzaoui1

1 National Centre of Nuclear Energy, Sciences and Techniques (CNESTEN), Morocco.

 2 LPNR, Mohammed V-Agdal University, Faculty of Sciences, Morocco.

Abstract: The Gamma-Ray scanning technique effective means for the diagnosis and identification of installations and process's problems in general and in particular in the case of distillation columns without aborting the production process.  Because of the different difficulties that can complicate a scan's profile interpretation and in order to benefit from the continuous advent of the new technologies in the electronics and the data processing fields, the team of the division of instrumentation and industrial application at the National Centre of Nuclear Energy,  Sciences and Techniques conducts a project aiming the elaboration of an expert system for acquisition, processing and interpretation of the data delivered by the gauge used for the Gamma-Ray scanning. This system consists of two main modules. The first one is for the preparation and control of the scans' progress conditions. The second is developed in order to make the automatic analysis and interpretation of the scans' profiles more reliable, easy and effective. In a first step, we have developed software which permits real time control of all the elements that come into play at the time of the realization of an exploration by Gamma-Ray scanning.

Keywords: Gamma-ray scanning, distillation columns, expert system.

Received May 22, 2006; accepted July 23, 2006

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Wednesday, 18 June 2008 02:26

A Novel Mechanism to Improve Performance of TCP Protocol over Asymmetric Networks

Wissam Al-Khatib and K. Gunavathi

Department of Electronics and Communication Engineering, PSG College of Technology, India

Abstract: In this paper, TCP performance issues in bandwidth asymmetric networks are investigated. Related works to improve TCP performance in bandwidth asymmetric networks are introduced and analyzed. A new mechanism to improve TCP performance in two way traffic over asymmetric networks is also proposed in this paper, which can further improve TCP performance by assigning the bandwidth rates over the reverse link dynamically. Simulation results show that the new mechanism has better performance compared to existing algorithms in terms of good utilization of the existing resources and higher throughput.

Keywords: asymmetric networks, TCP performance, ACK, bandwidth allocation.

Received May 1, 2006; Accepted August 8, 2006

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Wednesday, 18 June 2008 02:24

Comparative Performance of Hybrid SCM SAC-OCDMA System Using Complementary and AND Subtraction Detection Techniques

Ratna Sahbudin1, Syed Aljunid1, Mohd Abdullah1, Mohd bin Abdul Samad1,  Mohd Mahdi1, and Mahamod Ismail2

1Department of Computer and Communication System Engineering, Faculty of Engineering, Universiti Putra Malaysia, Malaysia.

2Department of Electrical, Electronics and Systems, Faculty of Engineering, Universiti Kebangsaan Malaysia, Malaysia.

Abstract: This paper presents the comparative performance of two detection schemes based on subtraction detection technique for a hybrid scheme of subcarrier multiplexed spectral-amplitude-coding optical code division multiple access (SCM SAC-OCDMA) system. SAC-OCDMA systems are receiving more attention because of their ability to completely eliminate multi access interference by using code sequences with fixed in-phase cross correlation. On the other hand, the SCM scheme is capable of improving the channel data rate of OCDMA systems. This hybrid scheme is proposed for the benefit of combining the advantages of both schemes. Consequently, the hybrid system is robust against interference and is much more spectrally efficient. Double weight code family is a new code structure used for SAC-OCDMA system. The experimental simulation results show that the proposed new AND subtraction detection technique improve the system performance significantly.  

Keywords: Hybrid SCM SAC-OCDMA, subtraction detection technique, multi access interference, optical communication system.

Received April 26, 2006; accepted July 31, 2006

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Wednesday, 18 June 2008 02:22

Implementation of a Novel Efficient Multiwavelet

Based Video Coding Algorithm

Sudhakar Radhakrishnan and Jayaraman Subramaniam

Department of Electronics and Communication Engineering, PSG College of Technology, India.

Abstract: The recent explosion in digital video storage and delivery has presented strong motivation for high performance video compression solutions. An efficient video compression technique must preserve the trade-off between compression ratio and the quality of the video. The performance of existing image and video coding standards generally degrade at low bit-rates because of the underlying block based Discrete Cosine Transform (DCT) scheme. Over the past decade, the success of wavelets in solving many different problems has contributed to its unprecedented popularity. Due to implementation constraints scalar wavelets do not posses all the properties which are needed for better performance in compression. New class of wavelets called ‘Multiwavelets’ which posses more than one scaling filters overcomes this problem. The objective of this paper is to develop an efficient compression scheme for the video stream by fast motion estimation algorithms up to half pixel accuracy as in newest international standard, ITU-T H.264/AVC, and to obtain better quality and higher compression ratio through multiwavelet transform and embedded coding of multiwavelet coefficients through Set Partitioning In Hierarchical Trees algorithm (SPIHT).

Keywords: video compression, quantization, prediction, entropy coding, multiwavelets, scaling functions.

Received April 7, 2006; Accepted December 1, 2006

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Wednesday, 18 June 2008 02:21

Novel Image Compression Using Multiwavelets with SPECK Algorithm

Sudhakar Radhakrishnan and Jayaraman Subramaniam

 Department of Electronics and Communication Engineering, PSG College of Technology, India.

Abstract: Compression is the process of representing information in a compact form so as to reduce the bit rate for transmission or storage while maintaining acceptable fidelity or data quality. Over the past decade, the success of wavelets in solving many different problems has contributed to its unprecedented popularity. For best performance in image compression, wavelet transforms require filters that combine a number of desirable properties, such as orthogonality and symmetry. Due to implementation constraints scalar wavelets do not possess all the properties which are needed for better performance in compression. New class of wavelets called ‘Multiwavelets’ which possess more than one scaling filters overcomes this problem. The objective of this paper is to develop an efficient compression scheme and to obtain better quality and higher compression ratio using Multiwavelet transform with Set Partitioned Embedded bloCK coder algorithm (SPECK). A comparison of the best known multiwavelets is made to the best known scalar wavelets. Extensive experimental results demonstrate that our techniques exhibit performance equal to, or in several cases superior to, the current wavelet filters.

Keywords: wavelet, multiwavelet, SPIHT, SPECK.

Received April 17, 2006; Accepted August 30, 2006

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Wednesday, 18 June 2008 02:19

Towards Ontology Extraction from Data-Intensive Web Sites: An HTML Forms-Based Reverse Engineering Approach

Sidi Benslimane1, Mimoun Malki1, Mustapha Rahmouni2, and Adellatif Rahmoun3

1Evolutionary Engineering and Distributed Information Systems Laboratory, Computer ScienceDepartment, University of Sidi Bel Abbes, Algeria

2Computer Science Department, University of Es-senia Oran, Algeria

3King Faisal University, CCS&IT, Hasa, KSA

 

Abstract:  The advance of the Web has significantly and rapidly changed the way of information organization, sharing and distribution. However, most of the information that is available has to be interpreted by humans; machine support is rather limited. The next generation of the web, the semantic web, seeks to make information more usable by machines by introducing a more rigorous structure based on ontology.  In this context we try to propose a novel and integrated approach for migrating data-intensive web into ontology-based semantic web and thus, make the web content machine-understandable. Our approach is based on the idea that semantics can be extracted from the structures and the instances of HTML forms which are the most convenient interface to communicate with relational databases on the current Web. This semantics is exploited to help build ontology. 

Keywords: information search and retrieval, online information services, applications and expert systems, semantic web, data-intensive web, reverse engineering.

Received August 4, 2006; Accepted November 20, 2006

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Wednesday, 18 June 2008 02:17

Internet Connectivity for Mobile Ad Hoc Networks Using Hybrid Adaptive Mobile Agent Protocol

Velmurugan Ayyadurai1 and Rajaram Ramasamy2

1Department of Electronics Engineering, Anna University, India.

2Department of Information Technology, Thiagarajar College of Engineering, India.

 

Abstract: Internet-based Mobile Ad Hoc Networking (MANET) is an emerging technology that supports self-organizing mobile networking infrastructures. This is expected to be of great use in commercial applications for the next generation internet users. A number of technical challenges are faced today due to the heterogeneous, dynamic nature of this hybrid MANET. A new hybrid routing scheme AODV ALMA is proposed, which act simultaneously combining mobile agents to find path to the gateway and on-demand distance vector approach to find path in local MANET is one of the unique solution. An adaptive gateway discovery mechanism based on mobile agents making use of pheromone value, pheromone decay time and balance index is used to estimate the path and next hop to the gateway. The mobile nodes automatically configure the address using mobile agents first selecting the gateway and then using the gateway prefix address. The mobile agents are also used to track changes in topology enabling high network connectivity with reduced delay in packet transmission to Internet. The performance tradeoffs and limitations with existing solutions for various mobility conditions are evaluated using simulation.

Keywords: Hybrid MANET, mobile agents, AODV ALMA, adaptive gateway discovery.

Received April 7, 2006; Accepted December 1, 2006

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Wednesday, 18 June 2008 02:13

Using WordNet for Text Categorization 

 

Zakaria Elberrichi1, Abdelattif Rahmoun2, and Mohamed Amine Bentaalah1

1EEDIS Laboratory, Department of Computer Science, University Djilali Liabès, Algeria

2King Faisal University, Saudi Arabia

                       

Abstract: This paper explores a method that use WordNet concept to categorize text documents. The bag of words representation used for text representation is unsatisfactory as it ignores possible relations between terms. The proposed method extracts generic concepts from WordNet for all the terms in the text then combines them with the terms in different ways to form a new representative vector. The effects of this method are examined in several experiments using the multivariate chi-square to reduce the dimensionality, the cosine distance and two benchmark corpus the reuters-21578 newswire articles and the 20 newsgroups data for evaluation. The proposed method is especially effective in raising the macro-averaged F1 value, which increased to 0.714 for the Reuters from 0.649 and to 0.719 for the 20 newsgroups from 0.667.

Keywords: 20Newsgroups, ontology, reuters-21578, text categorization, wordNet, and cosine distance.

Received April 5, 2006; Accepted August 1, 2006

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Wednesday, 18 June 2008 02:11

Integration of the Association Ends within

UML State Diagrams

Thouraya Bouabana-Tebibel1 and Mounira Belmesk2

1National Institute of Computer Science, INI BP 68 M Oued-Smar 16309, Algiers  

2Edouard Monpetit College, longueuil, Canada

 

Abstract: UML currently still lacks a rigorously defined semantics for its models, which makes formally analyzing a model and verifying its properties extremely difficult. To remedy that, we first present a technique for transforming the UML statechart diagrams into Petri nets. Then we develop an approach based on the class association ends. This approach shows how to validate the system invariants, expressed in the Object Constraint Language, on the Petri nets derived from the UML models. System property validation starts with an initialization of the model, extracted from the object and sequence diagrams. A case study is given throughout the paper to illustrate the methodology.

Keywords: UML, OCL, Petri nets, temporal logics, verification.

Received March 19, 2006; accepted September 7, 2006

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Wednesday, 18 June 2008 02:10

Message form the Editors  

  

Vectorial Information Structuring for Documents Filtering and Diffusion

Omar Nouali and Abdelghani Krinah

Basic Software Laboratory, CERIST, Algeria

Abstract: Information retrieval tries to identify relevant documents for an information need. The problems that an IR system should deal with include document indexing (which tries to extract important content from a document), user needs analysis (similar to document indexing but applied to a query), and their internal representation which makes them suitable for being explicitly manipulated by the corresponding algorithms (i.e., matching the query with the documents). This paper describes a vectorial approach for information organization, and its application to search/retrieval systems from a vast amount of textual data.

Keywords: Vectorial information structuring, information filtering, terms classification, documents diffusion.

Received March 7, 2006; accepted June 6, 2006

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