Message form the Editors  

Recognition of Printed Assyrian Character Based on Neocognitron Artificial Neural Network

Nazar Saaid Sarhan¹ and Laheeb Al-Zobaidy²

¹Department of Software Engineering, Al-Isra Private University, Jordan

²Department of Computer Science, University of Mosul, Iraq 

Abstract: This paper presents the development of Assyrian machine printed character recognition system. Well-known neocognitron artificial neural network is chosen for its fast processing time and its good performance for pattern recognition problems. The average recognition rate of 95% has been achieved this confirms that the proposed neocognitron artificial neural network approach is suitable for the development of Assyrian machine printed character recognition system. 

Keywords: Assyrian machine printed character recognition, neocognitron artificial neural network, whitespace, feature extraction. 

Non-Real Time Reliable Multicast Protocol

Using Sub Sub-Casting

Ali Alsaih¹ and Tariq Alahdal²

¹ Department of Electrical and Computer Engineering, Sana’a University, Yemen

²Department of Communication Technology and Networks, University Putra Malaysia, Malaysia 

Abstract: In this paper, a Reliable Multicast transport protocol over combined (fixed/mobile) networks using Sub Sub-casting called (RMSS) is proposed. RMSS is based on a hierarchical structure where receivers are grouped into local regions. In each local region there are special receivers, which are called Designated Receivers (DRs) and Mobile Agents (MAs). Each DR or MA is responsible for retransmission of requested packets to the receivers which belong to its local region. DRs and MAs send their acknowledgments periodically to the sender. They also process the acknowledgments sent to them from the Fixed Hosts (FHs) and Mobile Hosts (MHs) and they retransmit lost packets to the requesting receivers. A sub sub-casting technique is applied within these relatively smaller regions, where the repaired packets are retransmitted only to the requested receivers of the local group. These receivers form a sub group of the local group which itself is a subgroup of the global multicast group.  By applying sub sub-casting technique the number of duplicated packets due to retransmission of packets drops to zero which improves the system performance. Simulations (using C++) have demonstrated the scalability of RMSS with sub sub-casting technique. 

Keywords: Reliable multicast, designated receiver, mobile agent, sub sub-casting. 

Fault Detection in Dynamic Rule Bases Using Spanning Trees and Disjoint Sets

Nabil Arman

Palestine Polytechnic University, Palestine 

Abstract: Many fault detection techniques/algorithms for detecting faults in rule bases have appeared in the literature. These techniques assume that the rule base is static. This paper presents a new approach/algorithm for detecting faults in dynamic rule bases, where rules may be added/deleted in response to certain events happening in the system being controlled by the rule base. This is performed by maintaining a set of structures, where new rules can be added to the dynamic rule base without the need to rebuild the structures that represent the rule base. The approach makes use of spanning trees and disjoint sets to check a dynamic rule base for different kinds of faults. The algorithm devises a tree/forest of the underlying directed graph by treating the directed graph as an undirected graph, and then checks for various faults and properties. The algorithm devises a new rule base (which is a subset of the current rule base) that is equivalent, in terms of its reasoning capabilities, to the current rule base, with the properties that the new rule base is fault free. This is performed as rules are being added to the dynamic rule base one at a time.  

 Keywords: Dynamic rule bases, rule base faults, spanning trees. 

Received October 1, 2005; accepted March 15, 2006

A Service-Level Security Protocol for Bluetooth Scatternets

Fathi Taibi¹ and Toufik Taibi²

¹Faculty of Information Technology, University of Tun Abdul Razak, Malaysia

²College of Information Technology, United Arab Emirates University, UAE

Abstract: Bluetooth is the term used to describe the protocol of short-range, and frequency hopping radio link between devices. Bluetooth enables users to connect wirelessly to a wide range of computing and communication devices easily and it provides opportunities for rapid ad hoc connections. In this type of networks, security is one of the main issues. Bluetooth link-level security provides authentication of the communicating participants and exchange of encrypted data at the link-level. The existing Bluetooth security mechanism has limitations regarding strength, flexibility and efficiency. In this paper, a critical analysis on Bluetooth link-level security mechanism is provided, and a new Bluetooth service-level security protocol is proposed to overcome the limitations of the existing security mechanism. 

Keywords: Bluetooth, scatternet, service-level, security protocol. 

Fuzzy Active Queue Management for Congestion Control in Wireless Ad-Hoc

Essam Natsheh, Adznan B. Jantan, Sabira Khatun, and Shamala Subramaniam

 Department of Computer and Communication Systems, University Putra Malaysia, Malaysia 

Abstract: Mobile ad-hoc network is a network without infrastructure where every node has its own protocols and services for powerful cooperation in the network. Every node also has the ability to handle the congestion in its queues during traffic overflow. Traditionally, this was done through Drop-Tail policy where the node drops the incoming packets to its queues during overflow condition. Many studies showed that early dropping of incoming packet is an effective technique to avoid congestion and to minimize the packet latency. Such approach is known as Active Queue Management (AQM). In this paper, an enhanced algorithm, called Fuzzy-AQM, is suggested using fuzzy logic system to achieve the benefits of AQM. Uncertainty associated with queue congestion estimation and lack of mathematical model for estimating the time to start dropping incoming packets makes the Fuzzy-AQM algorithm the best choice. Extensive performance analysis via simulation showed the effectiveness of the proposed method for congestion detection and avoidance improving overall network performance.

 Keywords: Active queue management, ad-hoc networks, fuzzy systems, intelligent networks, network congestion. 

Can Function Points be Mapped to Object Points?

Ayman Issa¹, Mohammed Odeh1, and David Coward²

¹Centre for Complex Cooperative Systems, CEMS Faculty, University of the West of England, UK

²School of Computer Science, CEMS Faculty, University of the West of England, UK 

Abstract: Object points is a new software size metric that has emerged to cope with recent developments in software engineering, and to overcome the deficiencies of the traditional lines of code and function points size metrics. Moreover, object points has been utilized as the basis for several software cost estimation models with promising improvements in the accuracy of estimates. However, the infancy of the object points size metric means that there is a shortage of object points based software historical projects, on which to base the empirical validation of the new object points based software cost estimation models. Hence, the relationship between the extensively used function points and newly invented object points size metrics have been conceptualized and utilized in a novel forward approach to convert the function points projects data into their equivalent object points data. Empirical investigations of 66 function points projects have shown high correlation and significance, 88% and 0.33, respectively, between the resulting object points effort estimates and the actual function points effort. Furthermore, the resulting object points data have been utilized to model the embodied function points-object points relationship in two specialized productivity factors and function points type dependent linear models. The resulting models have shown high fitness, R2, values of 0.95, for both models.

Keywords: Software size metrics, function points, object points, software cost estimation.

A Framework for Quality of Service in Mobile

 Ad Hoc Networks

Francis Ogwu¹, Mohammad Talib¹, Ganiyu Aderounmu², and Adedayo Adetoye²

¹Department of Computer Science, University of Botswana, South Africa

²Department of Computer Science and Engineering, Obafemi Awolowo University, Nigeria 

Abstract: This paper presents a framework for specifying a probabilistic Quality of Service (QoS) guarantee in a mobile ad hoc network. The framework uses the mobility profiles of nodes in the network to establish probabilistic QoS. The network can deliver for a specified period of time. A mobility model was used to characterize the probabilities of path availability between two communicating nodes and QoS deliverable on the path. Mathematical models were developed for the probability of link and path availability, and bandwidth using continuous time stochastic mechanism. The proposed model was simulated using MATLAB version 5.2. The results of the research work show that the bandwidth guaranteed over a path diminishes with time, number of hops, and cell radius for a given mobility profile. Hence, a QoS-based routing algorithm can select more stable paths based on these metrics. This work provides a powerful paradigm for conception and dimensioning of the QoS deliverable by a MANET.

 Keywords: Probabilistic QoS guarantee, MANET, path availability, QoS prediction. 

Fuzzy Logic Control of Robot Manipulator in the Presence of Fixed Obstacle

Salah Kermiche, Saidi Mohamed Larbi, and Hadj Ahmed Abbassi

Automatic and Signal Laboratory, Faculty of Engineering, Annaba University, Algeria

 Abstract: This paper presents a solution for the problem of learning and controlling a 2R-plan robot manipulator in the presence of fixed obstacle. The objective is to move the arm from an initial position (source) to a final position (target) without collision. Potential field methods are rapidly gaining popularity in obstacle avoidance applications for mobile robots and manipulators. The idea of imaginary forces acting on a robot has been suggested by Andrews and Hogen [1983] and Khatib [1985]. Thus, we propose an approach based on potential fields principle, we define the target as an attractive pole (given as a vector directly calculated from the target position) and the obstacle as a repulsive pole (a vector derived by using fuzzy logic techniques). The linguistic rules, the linguistic variables and the membership functions are the parameters to be determined for the fuzzy controller conception. A learning method based on gradient descent for the self tuning of these parameters is introduced. Thus, it is necessary to have an expert person for moving the arm manually. During this operation of teaching, the arm moves and memorizes the data (inputs and outputs). This operation is used to find the controller parameters in order to reach the desired outputs for given inputs. 

Keywords: Robot manipulator, fuzzy logic control, obstacle avoidance method, self tuning, surface, deep structure. 

Routing Security in Open/Dynamic Mobile Ad Hoc Networks

Jameela Al-Jaroodi

College of Information Technology, United Arab Emirates University, UAE 

Abstract:Current technologies and security advances have made networked systems and applications very popular and widely used. The pervasive and practical aspects of wireless Mobile Ad Hoc Networks (MANET) made them very popular as well. This created the need for securing MANETs to provide users with authentic communications, secure and robust information exchange, and efficient security mechanisms. However, many of the security solutions devised for regular networks are not as efficient nor as effective on MANETs. This paper investigates the security issues of a common type of MANETs (open/dynamic MANET) at the network layer where routing protocols and forwarding mechanisms are used. In this paper, we identify the different security requirements specific to MANETs and survey some of the available secure routing techniques. The study has revealed some problems with the current routing protocols and identified the most important issue that needs to be resolved to ensure a secure network layer.   

Keywords: MANET, distributed routing, ad hoc networks, security, network layer, secure routing protocols.

Efficient Real Time Face Tracking Operator Study and Implementation Within Virtex FPGA Technology

Messaoud Mostefai¹, Mechta Djamila¹, and Youssef Chahir²

 ¹Computer Science Department, University of Bordj Bou Arreridj, Algeria

²Computer Science Department, University of Caen, France

Abstract: In this paper, we present the development of a new real time face-tracking operator. This last is based on motion detection techniques, less complex than techniques based on skin color, which are sensitive to illumination or those based on geometric standards which are efficient but expensive in computation tasks. The developed operator allows a robust face tracking with a considerable reduction in hardware resources, more particularly memory resources, which remains a powerful criterion in the construction of real time embedded systems. Moreover, the operator maps efficiently into a highly pipelined architecture, well suited for an implementation in reconfigurable technology. The developed operator is implemented on a Virtex FPGA architecture. The obtained experimental results show the effectiveness and correctness of our approach. 

Keywords: Face tracking, motion detection, real time, reconfigurable technology. 

Message form the Editors  

Area Flexible GF(2k) Elliptic Curve Cryptography Coprocessor

Adnan Abdul-Aziz

GutubComputer Engineering Department, King Fahd University of Petroleum and Minerals, SA 

Abstract: Elliptic Curve Cryptography (ECC) is popularly defined either over GF(p) or GF(2k). This research modifies a GF(p) multiplication algorithm to make it applicable for GF(2k). Both algorithms, the GF(p) and GF(2k), are designed in hardware to be compared. The GF(2k) multiplier is found to be faster and smaller. This GF(2k) multiplier is further improved to benefit in speed, it gained more than 40% faster speed with the cost of 5% more area. This multiplier hardware is furthermore adjusted to have area flexibility feature, which is used as the basic block in modeling a complete projective coordinate GF(2k) ECC coprocessor.