Fawzy A. Torkey

Cloud task scheduling based on ant colony optimization

Cloud computing is the development of distributed computing, parallel computing and grid computing, or defined as the commercial implementation of these computer science concepts. One of the fundamental issues in this environment is related to task scheduling. Cloud task scheduling is an NP-hard optimization problem, and many meta-heuristic algorithms have been proposed to solve it. A good task scheduler should adapt its scheduling strategy to the changing environment and the types of tasks. In this paper a cloud task scheduling policy based on ant colony optimization algorithm compared with different scheduling algorithms FCFS and round-robin, has been presented. The main goal of these algorithms is minimizing the makespan of a given tasks set. Ant colony optimization is random optimization search approach that will be used for allocating the incoming jobs to the virtual machines. Algorithms have been simulated using Cloudsim toolkit package. Experimental results showed that the ant colony optimization outperformed FCFS and round-robin algorithms.

Virtual Machine Placement Based on Ant Colony Optimization for Minimizing Resource Wastage

Cloud computing is concept of computing technology in which user uses remote server for maintain their data and application. Resources in cloud computing are demand driven utilized in forms of virtual machines to facilitate the execution of complicated tasks. Virtual machine placement is the process of mapping virtual machines to physical machines. This is an active research topic and different strategies have been adopted in literature for this problem. In this paper, the problem of virtual machine placement is formulated as a multi-objective optimization problem aiming to simultaneously optimize total processing resource wastage and total memory resource wastage. After that ant colony optimization algorithm is proposed for solving the formulated problem. The main goal of the proposed algorithm is to search the solution space more efficiently and obtain a set of non-dominated solutions called the Pareto set. The proposed algorithm has been compared with the well-known algorithms for virtual machine placement problem existing in the literature. The comparison results elucidate that the proposed algorithm is more efficient and significantly outperforms the compared methods on the basis of CPU resource wastage and memory resource wastage.

A new methodology for Web testing

As Web sites becoming a fundamental component of businesses, quality of service will be one of the top management concerns. Users, normally, does not care about site failures, traffic jams, network bandwidth, or other indicators of system failures. To an online customer, quality of service means fast, predictable response service, level of a Web site noted in a real time. User measures the quality by response time, availability, reliability, predictability, and cost. Poor quality implies that the customer will no longer visit the site and hence the organization may loose business. The issues that affects the quality are, broken pages and faulty images, CGI-bin error messages, complex colour combinations, no back link, multiple and frequent links, etc. So we try to build a good program that can scan web site for broken links, broken images, broken pages and other common web sit e faults. Because web site cannot test as a whole in one attempt we rely in our implementation to decompose the behavior of the web site into testable components then mapping these components onto testable objects. Then we prove by using Jmeter performance testing tool that broken components on a web site has a bad effect in its performance.

A robust methodology for performance evaluation of communication networks protocols

Performance evaluation is required at every stage in the life cycle of a network protocol. Analytical modeling is the method of choice for fast and cost effective evaluation of a network protocol. One of the most efficient high level formalisms used for analytical modeling of network protocols is stochastic Petri nets (SPNs). Yet, complexity of nowadays network protocols, which results in the state space explosion of the underlying Markov Chains (MC) model, has hindered the wide use of SPNs in the analysis of these protocols. Decomposition techniques are considered one of the main methodologies used for the approximate solution of the state explosion problem. Unfortunately, most of these techniques either require special form of the model or give insufficient accuracy of the solution. Moreover, small rates of communication protocols have caused additional overhead on any proposed technique for approximate evaluation of these protocols. This paper presents a novel decomposition technique called behavior and delay equivalent block (BDEB) technique. This technique overcomes most of drawbacks of other techniques proposed in the literature. It introduces a new aggregation method that depends on using a new type of transitions called intelligent transition. The proposed technique adopts delay equivalent criteria but in a new philosophy different from other techniques using the same criteria. The new technique is explained by applying it to a scalable model of the courier protocol

Reducing the Wavelet Ringing Artifacts in a Low-Complexity Video Codec

A low-complexity wavelet-based video coding technique is proposed. The devised technique adopts JPEG-2000 image coding. The wavelet transformation and subband quantization are developed and optimized in order to reduce the ringing artifacts especially at very low bit rate. The proposed coding technique reduces the coding complexity and performs well at average PSNR. As compared to other rival coding methods the proposed coding policy has a good compression ratio and an improved visual quality.

REDUCING THE WAVELET RINGING ARTIFACTS IN A LOW-COMPLEXITY VIDEO CODEC

A low-complexity wavelet-based video coding technique is proposed. The devised technique adopts JPEG-2000 image coding. The wavelet transformation and subband quantization are developed and optimized in order to reduce the ringing artifacts especially at very low bit rate. The proposed coding technique reduces the coding complexity and performs well at average PSNR. As compared to other rival coding methods the proposed coding policy has a good compression ratio and an improved visual quality