Abdullah Mohd Zin

Performance study of selective encryption in comparison to full encryption for still visual images

Securing digital images is becoming an important concern in today’s information security due to the extensive use of secure images that are either transmitted over a network or stored on disks. Image encryption is the most effective way to fulfil confidentiality and protect the privacy of images. Nevertheless, owing to the large size and complex structure of digital images, the computational overhead and processing time needed to carry out full image encryption prove to be limiting factors that inhibit it of being used more heavily in real time. To solve this problem, many recent studies use the selective encryption approach to encrypt significant parts of images with a hope to reduce the encryption overhead. However, it is necessary to realistically evaluate its performance compared to full encryption. In this paper, we study the performance and efficiency of image segmentation methods used in the selective encryption approach, such as edges and face detection methods, in determining the most important parts of visual images. Experiments were performed to analyse the computational results obtained by selective image encryption compared to full image encryption using symmetric encryption algorithms. Experiment results have proven that the selective encryption approach based on edge and face detection can significantly reduce the time of encrypting still visual images as compared to full encryption. Thus, this approach can be considered a good alternative in the implementation of real-time applications that require adequate security levels.

Comparing the Accuracy of End-to-End Network Performance Measurement Testbed and Simulation Model for Data Transfers in Heterogeneous Environment

We present a novel approach for the measurement of one-way delays and throughput between network nodes in heterogeneous environment. This research investigates performance evaluation of remote data transfers on heterogeneous services and technologies environment. We propose an enhanced equation to evaluate the performance of network traffic management via Little Law and Queuing theory to improve the evaluation algorithm. To get accuracy results on the performance of simulation model, we measure (verify and validate) data from lab experiment. We use network management tool to capture those data and Ping Plotter application (network analyzer) to generate traffic. As a result, this simulation model can provide a good approximation of the real traffic (one-way delays and throughput) observed in the real network environment.

Development of simulation model in heterogeneous network environment: Comparing the accuracy of simulation model for data transfers measurement over wide area network

We present a novel approach for the measurement of one-way delays and throughput between network nodes in heterogeneous environment over Wide Area Network (WAN). This research investigates performance evaluation of remote data transfers on heterogeneous services and technologies environment. We propose an enhanced equation to evaluate the performance of network traffic management via Little Law and Queuing theory to improve the evaluation algorithm. To get accuracy results on the performance of simulation model, we measure (verify and validate) data from lab experiment. We use network management tool to capture those data and Ping Plotter application (network analyzer) to generate traffic. As a result, this simulation model can provide a good approximation of the real traffic (one-way delays and throughput) observed in the real network environment (Wide Area Network, WAN). Through laboratory and field experiments, it shows that the model via simulation is capable of approximating the performance of remote data transfers over heterogeneous services and techniques within a minimum error range.

A parallel membrane inspired harmony search for optimization problems

Display Omitted Harmony Search is enhanced by improving the speed of convergence while preventing premature convergence to a local minimum.Membrane computing model is employed to execute parallelized HS efficiently to increase the diversity of HS and improving the performance of HS.Simulation results showed that the application of the proposed approach to different variants of harmony search yielded better performance than previous approaches.We applied the parallel membrane-inspired HS to the flexible job shop scheduling problem and well-known benchmark instances to demonstrate the effectiveness of the proposed algorithm. Harmony search is an emerging meta-heuristic optimization algorithm that is inspired by musical improvisation processes, and it can solve various optimization problems. Membrane computing is a distributed and parallel model for solving hard optimization problems. First, we employed some previously proposed approaches to improve standard harmony search by allowing its parameters to be adaptive during the processing steps. Information from the best solutions was used to improve the speed of convergence while preventing premature convergence to a local minimum. Second, we introduced a parallel framework based on membrane computing to improve the harmony search. Our approach utilized the parallel membrane computing model to execute parallelized harmony search efficiently on different cores, where the membrane computing communication characteristics were used to exchange information between the solutions on different cores, thereby increasing the diversity of harmony search and improving the performance of harmony search. Our simulation results showed that the application of the proposed approach to different variants of harmony search yielded better performance than previous approaches. Furthermore, we applied the parallel membrane inspired harmony search to the flexible job shop scheduling problem. Experiments using well-known benchmark instances showed the effectiveness of the algorithm.

Parallel and distributed computing models on a graphics processing unit to accelerate simulation of membrane systems

Abstract Membrane systems are parallel distributed computing models that are used in a wide variety of areas. Use of a sequential machine to simulate membrane systems loses the advantage of parallelism in Membrane Computing. In this paper, an innovative classification algorithm based on a weighted network is introduced. Two new algorithms have been proposed for simulating membrane systems models on a Graphics Processing Unit (GPU). Communication and synchronization between threads and thread blocks in a GPU are time-consuming processes. In previous studies, dependent objects were assigned to different threads. This increases the need for communication between threads, and as a result, performance decreases. In previous studies, dependent membranes have also been assigned to different thread blocks, requiring inter-block communications and decreasing performance. The speedup of the proposed algorithm on a GPU that classifies dependent objects using a sequential approach, for example with 512 objects per membrane, was 82×, while for the previous approach ( Algorithm 1 ), it was 8.2×. For a membrane system with high dependency among membranes, the speedup of the second proposed algorithm ( Algorithm 3 ) was 12×, while for the previous approach ( Algorithm 1 ) and the first proposed algorithm ( Algorithm 2 ) that assign each membrane to one thread block, it was 1.8×.

A Framework for Context-Aware University Mobile Organizer

With appearance of mobile devices such as cell phones, PDAs and smart phones, context-aware applications are becoming increasingly popular. Therefore, developers are always seeking for new and powerful developing tools for context-aware programming. Developers prefer to use fast and convenient development tools that can support all required possibilities for implementing a complete and user-friendly context-aware systems. In this paper, we determined some essential principles for developing and implementing context-ware applications. Technologies for context-aware applications programming should support these principles. Among different technologies, we introduced four technologies, which are most practical for developing context-aware applications based on determined principles. Java agent development environment, java context-awareness framework and J2ME are java-based technologies, which were studied in this paper. We also introduced spring.net technology as a new technology for designing context-aware application because of its novel features that can present an easy interactive and easy developing area for context-aware applications. Eventually, the proposed context-aware framework for an intelligent university mobile organizer by using spring.net technology is illustrated. This framework draws on spring.net components for developing a context-aware application.

Developing learning software for children with learning disabilities through Block-Based development approach

Children with learning disability such as autism who have serious impairments with social, emotional, and communication skills require a high degree of personalization in using the educational software develop for them. The aim of this paper is to propose Block-Based Software Development method and approach that enables the end-users (such as parents and teachers) to build application software to suit the different need of an autistic child. This research hopefully can produce useful tailorable learning software in order to assist educating autistic children.

Development of simulation model: An ethernet case study in heterogeneous environment

We present a novel approach for the measurement and estimation of network traffic utilization between network nodes in heterogeneous environment. We propose an enhanced equation to evaluate the performance of network interface via little law and queuing theories to improve the evaluation algorithm. To get accuracy results on the performance of simulation model, we verify and validate data from local area network (real network environment). We use network management tool to capture those data and Fluke Optiview device to generate traffic. As a result, this simulation model can provide a good approximation of the real traffic observed in the real network environment.

Converting differential-equation models of biological systems to membrane computing

This paper presents a method to convert the deterministic, continuous representation of a biological system by ordinary differential equations into a non-deterministic, discrete membrane computation. The dynamics of the membrane computation is governed by rewrite rules operating at certain rates. That has the advantage of applying accurately to small systems, and to expressing rates of change that are determined locally, by region, but not necessary globally. Such spatial information augments the standard differentiable approach to provide a more realistic model. A biological case study of the ligand-receptor network of protein TGF-β is used to validate the effectiveness of the conversion method. It demonstrates the sense in which the behaviours and properties of the system are better preserved in the membrane computing model, suggesting that the proposed conversion method may prove useful for biological systems in particular.

Whip: A framework for mashup development with block-based development approach

The emerging of Web 2.0 and Web 3.0 technologies allows web users not only authoring and customizing web pages and their content but also integrating the contents of several web sites into one web page. This web integration is called web mashup. There are various End Users Programming development approaches in making mashup such as scripting, dataflow, widget, spreadsheet, and Programming By Demonstration (PBD). Whip design, as a tool lets casual users - those without programming skill - do the mashup easily through Block-Based Programming (BBP) approach. The design of Whip is guided by a number of principles that support this goal; ranging from situational application, users preference, Users skill level to code sharing. In this paper we expound the philosophy of Whip design and explain how the design of Whip supports those principles.