Alaa Eddien Abdallah

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.

A Round-based Data Replication Strategy

Data Grid allows many organizations to share data across large geographical area. The idea behind data replication is to store copies of the same file at different locations. Therefore, if a copy at a location is lost or not available, it can be brought from another location. Additionally, data replication results in a reduced time and bandwidth because of bringing the file from a closer location. However, the files that need to be replicated have to be selected wisely. In this paper, a round-based data replication strategy is proposed to select the most appropriate files for replication at the end of each round based on a number of factors. The proposed strategy is based on Popular File Replicate First (PFRF) strategy, and it overcomes the drawbacks of PFRF. The simulation results show that the proposed strategy yields better performance in terms of average file delay per request, average file bandwidth consumption per request, and percentage of files found.

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.

Smart Partial Flooding Routing Algorithms for 3D Ad Hoc Networks

Abstract Mobile ad-hoc networks (MANETs) become an essential part of the current wireless communication infrastructure, thus efficient routing protocols takes an important consideration of the current research. In Geographic-Based routing algorithms, nodes use the location information about nodes to take routing choices. Current geographical routing algorithms usually address the routing environment in 2D space. However, in real life, nodes could be located in 3D space. In this paper, we propose two 3D geographical routing algorithms that uses the advantage of the high delivery rate of the flooding algorithms and the low overhead of the progress-based routing algorithms. The first algorithm (Progress-SGFlooding) uses geographical routing to progress as much as possible to the destination, if its not possible, a partial flooding is used over a sub-graph extracted locally. The second algorithm (Progress- SGFlooding-Progress) used geographical routing to progress to the destination, if the progress is not possible, a partial flooding is used over a sub-graph for one step only and then the algorithm goes back to the geographical routing. We evaluate our algorithm and compare it with current routing algorithms. The simulation results show a significant improvement in delivery rate up to 100% compared to 70% and a huge reduction in overall traffic around 60%.

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.

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.

A blind 3D watermarking technique using spherical coordinates and skewness measure

Three-dimensional watermarking is very useful for copyright protection, verification, and indexing. In this paper we propose a robust computationally inexpensive 3D polygonal mesh watermarking methodology. The new algorithm is based on vertex distribution and skewness measure. The core idea behind our algorithm is to modify the skewness measure based on a predefined secret message. The proposed algorithm is slightly altering the skewness distribution of several intervals extracted from a 3D model. The main attractive features of this approach is the improved performance of the data embedding system, perceptual invisibility and it is resistant to a variety of the most common attacks.

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

Authorship analysis is a long explored area in the computational research. Recently, there has been growing interest in developing intelligent systems that are capable of authorship identification. Inspired by recent works, we address the problem of author attribution of Arabic text. This area, in specific, has not been targeted in the literature except for few studies. However, it is a challenging problem as there are linguistic complexities associated with the Arabic language including elongation and inflection challenges. For this purpose, we propose a novel hybrid feature set consisting of: lexical, syntactic, structural and content-specific features for 456 instances belonging to seven different Arabic authors. For validation, we run extensive experiments with different intelligent classifiers and show the strength of the proposed feature set. Our results show that the proposed feature set has proved successful with a classification performance accuracy of 88% with the hold-out test and 82% with the cross-validation test.

Texture recognition by using a non-linear kernel

This study proposes the use of features combination and a non-linear kernel to improve the classification rate of texture recognition. The feature vector concatenates three different sets of feature: the first set is extracted using grey-level cooccurrence matrix, the second set is collected from three different radii of local binary patterns, and the third set is generated using Gabor wavelet features. Gabor features are the mean, the standard deviation, and the skew of each scaling and orientation parameter. The aim of the new kernel is to incorporate the power of the kernel methods with the optimal balance derived from the features. To verify the effectiveness of the proposed method, numerous techniques are tested using the three data sets, which consist of various orientations, configurations and lighting conditions.

Secure local algorithm for establishing a virtual backbone in 3D ad hoc network

Due to the limited lifetime of the nodes in ad hoc and sensor networks, energy efficiency needs to be an important design consideration in any routing algorithm. It is known that by employing a virtual backbone in a wireless network, the efficiency of any routing scheme for the network can be improved. Most of the current algorithms for electing the virtual backbone mainly focused on the energy balance among the network nodes without considering the nodes distribution in the real environment. In this paper, we use the nodes geometric locations to introduce a first secure algorithm that can construct the virtual backbone structure locally in 3D environment; we have proofed that our new algorithm construction time is constant.