Emad E. Abdallah

Enhanced Fast Spread Replication strategy for Data Grid

Data replication is used in Data Grid to enhance data availability and fault tolerance. However, replication should be used wisely because the storage size of each node reside on the Data Grid is limited. Thus, the node must accommodate only the important replicas. In this paper, a dynamic replication strategy that takes into account the number and frequency of requests, the size of the replica, and the last time the replica was requested is proposed. This strategy is an enhanced version of Fast Spread replication strategy. The simulation results show that the new proposed strategy attained better performance than Fast Spread with Least Recently Used (LRU) and Fast Spread with Least Frequently Used (LFU) in terms of total response time and total bandwidth consumption.

An Energy-Efficient Threshold-Based Clustering Protocol for Wireless Sensor Networks

Energy-constrained wireless sensor networks (WSNs) have been deployed widely for monitoring and surveillance purposes. Since sensor nodes (SNs) have significant power constraints (battery life), energy-efficient protocols must be employed to prolong the network lifetime. In this paper, we propose an energy-efficient protocol which provides a new way of creating distributed clusters. This protocol is a modified version of Low Energy Adaptive Clustering Hierarchy (LEACH) protocol. The experimental results show that our protocol that takes into account both the residual energy at each SN and the distance between the SNs outperforms LEACH protocol in terms of first node death time and average residual energy.

Simplified features for email authorship identification

We present an investigation analysis approach for mining anonymous email content. The core idea behind our approach is concentrated on collecting various effective features from previous emails for all the possible suspects. The extracted features are then used with several machine learning algorithms to extract a unique writing style for each suspect. A sophisticated comparison between the investigated anonymous email and the suspects writing styles is employed to extract evidence of the possible email sender. Extensive experimental results on a real data sets show the improved performance of the proposed method with very limited number of features.

Assistive Technology for Deaf People Based on Android Platform

Abstract Social communication is one of the most important pillars that our society based on. It is well-known that the language is the only way to communicate and interact with each other verbally or non-verbal way. People with special needs are members of this society and have the right to enjoy the communication with the external environment in an easy and professional manner. This paper aims to provide an interesting application that guarantees ultimate communication with the disabled users and vice versa. The key feature of this application is employing the Arabic language as a medium of communication to learn all the sign language terms. The power of this application appears in two aspects: first of all, the ability of normal people to communicate with the targeted people without having any previous knowledge on signs language. This can be either achieved by voice recognition of words or by typing the words in the Arabic language. The application is then displays the appropriate image(s) in the sign language. Secondly, and more importantly, people with special needs communicate with normal people by choosing the signs images on their phones from the numerous categories stored in the databases which express their ideas and thoughts. Consequently, the set of images is transformed into a text paragraph. We evaluated our application by testing it on real deaf and dumb users. We carefully created scenarios on realistic situations. The early results are promising as all deaf found the proposed technology useful and 90% of them wanted to use it on daily basis.

Simplified approach for generating integrity tests in distributed database systems

Distributed database systems (DDBS) usually contain massive collections of data that rapidly evolve over time. It is extremely time consuming to make a perfect checking at each database update operation. This paper introduces a new algorithm to generate simplified integrity tests which could be used to automatically verify that database updates does not introduce any violation of integrity. The main attractive features of this approach are simplicity, flexibility in generating sufficient and complete integrity tests, and considering all conjunctive and disjunctive constraints. The experiment results show that the new algorithm provides more tests in comparison with existing techniques.

Checking the efficiency of integrity tests in distributed and parallel database

With the increased use of the applications that deal with massive collections of data, integrity checking became a critical problem. Efficient checking could be achieved by deriving a simplified form of the integrity constraints against the new database state before the update operation is performed. Most of the research projects in this area are concentrated on deriving sufficient integrity tests for distributed databases. However, no attention has been given to validating the appropriateness of these integrity tests. In this paper, we provide a complete solution for checking constraints in the distributed database system. The proposed technique is not limited to generate sufficient and complete integrity tests but it also selects the suitable test from several alternative tests. Experimental results showed how the complete tests can significantly improve the performance of the constraint checking mechanisms with respect to the amount of data transferred across the network.

Randomized geographic-based routing with nearly guaranteed delivery for three-dimensional ad hoc network

Several routing algorithms have been proposed for efficient routing in mobile ad hoc networks, most of them consider mobile nodes embedded in two-dimensional environments. However, in reality, these networks are embedded in three-dimensional environments. Usually, two-dimensional routing algorithms have several assumptions that are not valid for three-dimensional spaces. In this article, we propose four different randomized geographic-based routing algorithms that have the following properties: (1) nearly guaranteed delivery rate, by using randomize route to overcome local minimum problems; (2) low overhead, by extracting a virtual backbone of the network and then conducting the routing algorithms over the extracted backbone to decrease the search space; (3) low path dilation, by hybridizing the new algorithms with progress-based routing which have very low path dilation; and (4) works in three-dimensional environment. The first algorithm 3DRanDom chooses the next neighbor randomly from a dominating set of the network (extracted locally). The second algorithm 3DRanDomProb extracts a dominating set and sends to one of the resulted neighbors randomly with more probability for the nodes closer to the destination. The third algorithm G_3DRanDomProb tries to progress as much as possible to the destination, if the progress is not possible, the algorithm switches to 3DRanDomProb. The fourth algorithm G_3DRanDomProb_G uses progress-based routing as much as possible, then it switches to 3DRanDomProb until it overcomes the local minimum problem and then goes back to progress-based routing. We show experimentally that these hybrid randomized routing algorithms on three-dimensional mobile ad hoc networks can achieve nearly guaranteed delivery while discovering routes significantly closer in length to the shortest path and with low overhead.

An Index-Based Approach for Wireless Sensor Networks

Sensor nodes have significant power constraints (battery life). Thus, power-aware approaches must be employed to prolong the network lifetime. However, most of the literature considers only routing-based approaches to prolong it. In this paper, we propose an index-based approach that provides a new way for reducing the energy consumption. The idea behind this new proposed approach is having an index for each possible value for a sensed reading. The index length will have much less length than the reading if the possible values for the sensed reading are limited. In this case, sending the corresponding index for a reading instead of the reading itself will result in decreasing the size of the submitted packet and therefore reducing the consumed energy. The experimental results show that our approach reduces both the total energy consumption and total elapsed time in the case the number of the possible different values for each sensed reading is up to 32,768

An intelligent system for author attribution based on a hybrid feature set

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