Volume 4, Issue 1, January 2013

Effect of Mobility Patterns on VoIP QoS in Mobile WiMAX

Muhammad Imran Tariq, Muhammad Ajmal Azad and Syed Khurram Rizvi

Japan Advanced Institute of Science and Technology, Japan
Faculty of Engineering, University of Porto, Portugal

Abstract - VoIP over Mobile WiMAX provides high data rate voice connectivity to high speed mobile as well as to fixed users. Voice over Internet Protocol (VoIP) enables the transport of voice data over internet protocol base networks. The WiMAX mobile network provides data services to both mobile as well as pedestrian users and the quality of voice is greatly affected with the mobility patterns of mobile users. The mobility behavior of the user plays an important role in determining the quality of Voice. For providing better quality of service to end user, the Mac layer of WiMAX defines various QoS classes for different types of applications. In this research paper, we analyze the performance of VoIP codecs over mobile WiMAX when resources are allocated to VoIP users using best effort Scheduling scheme. We analyze the performance of voice codecs under two conditions, first, the jitter buffer is enabled and disables, second the mobile user are moving at different speeds in random way point and group mobility patterns. Our comprehensive simulation results show that the performance of voice codecs remain same for random way point and group mobility patterns. Our results reveal that the G729 provides better voice quality as well as support more number of connections as compared to other voice codecs.

Index Terms - VoIP Codecs, Mobile WiMAX, Mobility Models and BE Scheduling Class

Finding the motif from DNA Sequences using Grid Computing System

Pages: 8-13 (6) | [Full Text] PDF (429K)

Trang Hong Son, Tran Van Lang and Le Van Vinh

Hoa Sen University, Vietnam Ministry of Education and Training, Vietnam
Institute of Applied Mechanics and Informatics, Vietnam Academy of Science and Technology, Vietnam
HCM City University of Technical Education, Vietnam Ministry of Education and Training, Vietnam

Abstract - The motif finding problem is one of high complex problems, as well as needs much time. Therefore, the accuracy and time consuming are two important goals in this problem. Many algorithms were proposed for solving the problem. However, execution time is still a challenge needing more research. In this paper, we proposed a parallel solution based on improving the Uniform Projection algorithm. Moreover, we implemented the program on the Grid computing environment to get better performance.

Index Terms - Biology Sequence, Finding Motif and Grid Computing

2D-LDA based Online Handwritten Kannada Character Recognition

Pages: 14-18 (5) | [Full Text] PDF (496K)

M. Mahadeva Prasad and M. Sukumar

Department of Studies in Electronics University of Mysore, Post Graduate Centre, Hassan, India
Department of Instrumentation Technology, S. J. College of Engineering, Manasagangothri Campus, Mysore, India

Abstract - Matrix based LDA (2D-LDA) is gaining importance as it overcomes the singularity problem in small sample size problem and also achieves better computational efficiency when compared to classical 1D-LDA. In 2D-LDA data is represented in matrix form rather than vector form before dimensionality reduction. In the present work, recognition performance of 2D-LDA for different feature combinations is compared in recognizing online handwritten Kannada Characters. Kannada basic character Set, popularly known as Kannada Varnamale is subjected to experimentation. Different feature combinations extracted from the size normalized characters are fed to 2D-LDA for dimensionality reduction and nearest neighbor classifier is used for classification. Writer independent experiments are carried out with 3750 samples for training and 1550 samples for testing. Among different feature combinations, second derivative feature and estimate feature combination has given a best average recognition accuracy of 88.3 %.

Index Terms - Kannada Characters, Kannada Varnamale Recognition, Online Handwriting and 2D-LDA

Towards a Viewpoint of Context-Aware Recommender Systems (CARS) and Services

Pages: 19-29 (11) | [Full Text] PDF (294K)

Nana Yaw Asabere

School of Software, Dalian University of Technology, Dalian, P.R. China

Abstract - Recommender Systems have been/are being researched and deployed extensively in various disciplines such as tourism and education. Most traditional recommender systems such as Collaborative Filtering (CF) and Content-Based Filtering (CBF) generate recommendations by using two main attributes, namely; users and items i.e. recommendations are generated based on a user having an interest or preference of a particular item resource. It has however been recently realized by researchers that it is important to incorporate context as part of a recommendation process in order to generate accurate and efficient recommendations for users of a particular system. Context such as location, time, activity, physical conditions, social interaction etc. according to research are very important and can be used in addition to users and items to generate trustworthy and accurate recommendation. Location and time context for examples are important in mobile computing recommendations, due to the fact that a user may require a recommendation at a particular location in a particular time. Such scenarios have introduced Context-Aware Recommender Systems (CARS) for further open research issues and challenges. This paper initially presents Background of CARS, specifically from the perspective of context types, context modeling architectures and algorithms. Furthermore, the paper, presents an overview of the state-of-the-art research in the area of CARS, and finally discusses relevant open issues of CARS.

Index Terms - Context-Awareness, Context-Aware Recommender Systems (CARS), Context and Services

FPGA Implementation of Modified Montgomery for RSA Cryptosystem

Pages: 30-34 (5) | [Full Text] PDF (190K)

Rupali Verma, Maitreyee Dutta and Renu Vig

PEC University of Technology, Chandigarh, India
National Institute of Technical Teachers Training and Research, Chandigarh, India
University Institute of Engineering and Technology, Panjab University, Chandigarh, India

Abstract - Modular multiplication is a key operation in public key cryptosystems like RSA. Among modular multiplication methods, Montgomery modular multiplication is an efficient algorithm suitable for hardware implementation. In this paper, a Modified Montgomery Modular Multiplication design is proposed with carry save adder architecture and parallel simplified quotient computation for the next iteration. The proposed design has a high clock frequency and high throughput. The proposed design and RSA are implemented on Virtex 2 and Virtex 5 FPGAs.

Index Terms - Carry Save Adders, Cryptography, Modular Multiplication and RSA Exponentiation

Gas Turbine LQR, INTEGRAL Controllers and Optimal PID Tuning by Ant Colony Optimization Comparative Study

Pages: 35-41 (7) | [Full Text] PDF (305K)

Ahmad M. Hamza, Mohamed S. Saad, Hassan M. Rashad and Ahmed Bahgat

Abstract - Gas turbine is considered one of the most significant sources for power generation in the last decades, its dynamics analysis become increasingly more important. There are two types of controllers for gas turbines which are classical and intelligent controllers. The Linear Quadratic Controller (LQR) and integral control are classical type. Ant Colony Optimization (ACO) is intelligent type. The Linear Quadratic Controller (LQR), Integral control and Ant Colony Optimization (ACO) are developed for controlling the responses of a Gas Turbine system. Several researches of controllers and algorithms are presented to obtain the optimal solutions of the cost function and controller parameters. In this paper, an implementation of the Linear Quadratic Controller (LQR), integral control and Ant Colony Optimization (ACO) are performed for the optimization of cost function and controller parameters using an objective function. Proposed work focus on classical verses intelligent controllers. Simulation results for the systems are presented in time domain. The simulation is performed using the Linear Quadratic Controller (LQR), integral control and Ant Colony Optimization (ACO). The results of LQR are compared with the others types. The results show that the LQR is the best according to rise time and settling time.

Index Terms - Gas Turbine, Transfer function, LQR, Integral Control, PID, ITSE and Ant Colony Optimization (ACO)

Image Edge Detection based on ACO Technique

Pages: 42-46 (5) | [Full Text] PDF (385K)

Mahendra Pratap Panigrahy and Shakil Ahmed

ECE, Institute of Technology Roorkee (ITR), India
CSE, Institute of Technology Roorkee (ITR), India

Abstract - Edges are the characteristic boundaries of any digital image and are therefore plays a fundamental importance in image processing task. Digital noisy Image Edge detection significantly reduces the amount of data and filters out the useless information, while preserving the important structural properties in an image. It is an important tool used in many applications: such as image processing, computer vision and pattern recognition. There exist several ant colony optimization algorithms, whereas the original algorithm, known as Ant System (AS), originates from the early nineties. Since then, a number of other algorithms, among the more successful variants MAX-MIN Ant System (MMAS) and Ant Colony System (ACS), were introduced. Several ACO-based approaches have been proposed to the edge detection problems. In this paper, a new ACO-based approach is applied to image edge detection. The approach makes use of improvements introduced in ACS, with the addition of a new direction control feature. The reason for introducing direction control is to make the ants better suited for detecting edges belonging to long and narrow openings, hence, edges belonging to cracks.

Index Terms - Image Processing, Noisy, Edge Detection, Filters, AS, MMAS and ACS

Agent Approach in Support of Enterprise Application Integration

Pages: 47-53 (7) | [Full Text] PDF (445K)

Djamel Benmerzoug

Faculty of NTIC, University of Constantine 2, Algeria

Abstract - The present approach highlights the synergies between application integration and interaction protocols. Since both fields have advanced in different directions, a number of important technical problems can be addressed by their proper synthesis. In our previous work [5], [6], [7], we proposed a methodological approach based on Interaction Protocols for Enterprise Application Integration (EAI). This approach permits to specify MAS (Multi-Agent System) interaction protocols, verify their behavior and use them to integrate multiple business applications. The result of the proposed approach is a validated interaction protocol. Based on this protocol, we define in this paper, an agent- based architecture for the EAI. It includes all the concepts necessary to support communication and coordination mechanisms such as inter-agent and agent-Web services communication.

Index Terms - Multi-agent System, Interaction Protocol and Enterprise Application Integration

Volume 4, Issue 1, January 2013

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