International Journal of New Computer Architectures and their Applications

797-809

Authors: Kenichi Takahashi, Takanori Matsuzaki, Tsunenori Mine, Takao Kawamura, Kazunori Sugahara

Some of Internet services require users to provide their information such as their name, address, credit card number, and an ID-password pair. In these services, the manner in which the provided information is used is solely determined by the service providers. As a result, even when the manner appears vulnerable, users have no choice to refuse, but to allow such usage. However, the owner of the information is the user. Thus, users along with the service providers should be able to determine the manner. In this paper, we propose such a framework that enables users to select. A policy defines the manner in which his/her information is to be protected, and its manner is incorporated into a program. By allowing a service provider to use the information through the program, the user can protect his/her information in his/her selected manner. Thus, in this scenario, both the service provider and the user can determine the type of protection for the user's information. Moreover, the responsibility of the service provider for information protection would be reduced as the user would determine the type of information protection. We show the validity of the proposed framework with an example scenario to protect user password.

821-837

Authors: Ahmed Al-Herz, Moataz Ahmed

Web applications testing and verification is becoming a highly challenging task. A number of model-based approaches has been proposed to deal with such a challenge. However, there is no criteria that could be used to aid practitioners in selecting appropriate approaches suitable for their particular effort. In this paper we present a set of attributes to serve as criteria for classifying and comparing these approaches and provide such aid to practitioners. The set of attributes is also meant to guide researchers interested in proposing new model-based Web application testing and verification approaches. The paper discusses a number of representative approaches against the criteria. Analysis of the discussion highlights some open issues for future research. In response to one of the issues, we present an approach for prioritizing components for testing to maximize confidence given a limited number of test cases to be executed. Some initial results are reported in the paper.

848-865

Authors: Mahamat Issa Haasn

Resource/service discovery is a very vital issue in Internet based distributed systems such as Grid and Cloud computing. In this paper we address the RD issue in intergrid. We design a service discovery framework by integrating semantic technology, peer-to-peer network and intelligent agents. The framework has two main components which are service description, and service registration and discovery models. The earlier consists of a set of ontologies that are used as a data model for service description and services to accomplish the description process. The service registration is based super-peer architecture to organize the nodes and on ontology to manage the node organization. In addition to that, we introduce intelligent agents to automate the discovery process. We evaluate the framework via simulation experiments, and the result confirms the effectiveness of the framework in satisfying the required RD features (interoperability, scalability, decentralization and dynamism).

879-893

Authors: Siti Arpah Ahmad, Mohd Nasir Taib, NoorElaiza Abd Khalid, Rohana Ahmad

Abnormalities are the main interest of dentists in examining the radiographs for determining any diseases that may appear at the apices of the teeth. However poor quality radiograph produces weak visual signal that may produce misleading interpretations. Hence the quality of radiograph influence dentists’ decision that reflects the success or failure of any suggested treatments. Therefore this work intend to analyze the abnormality found in intra-oral dental radiographs by comparing the original images with images that had been enhanced using compound enhancement algorithms (CEM) namely Sharp Adaptive Histogram Equalization (SAHE) and Sharp Contrast adaptive histogram equalization (SCLAHE). Results show that SCLAHE enhanced images provide slight improvement, compared to the original images, in detecting widen periodontal ligament space abnormality.

911-925

Authors: Nureize Arbaiy, Junzo Watada

This paper proposes a fuzzy goal programming that is developed by fuzzy random regression approach, to solve a multi-level multi-objective problem. Fuzzy random regression enables us to deal with fuzzy random circumstances and approximate the coefficients for the developed model. A numerical example of the production planning problem illustrates the proposed solution approach. The proposed method is important where the fuzzy random data is dealt in the mathematical model to solve the multi-level multi-objective decision making problem which can attain a satisfactory solution.

942-952

Authors: Zulkefli Mansor, Saadiah Yahya, Noor Habibah Hj Arshad

Software development project is one of the important areas in software engineering. Many researches have been conducted and looked into issues in software development project such as methodology used, costing, challenges, type of project and many more. However, the most crucial issues in software development project are costing. Moreover, current trend in software development project is adopting agile as methodology. Therefore, this paper aimed to discuss success factors that influence in traditional and agile cost estimation process for software development project. Literature survey is carried out from the past researches. Then, this paper presents the success factors that bring to the successful of traditional and agile cost estimation in software development project. Realisation these factors will help software development communities contribute positively to the success of traditional or agile cost estimation process in software development project.

977-990

Authors: Mahmood Ashraf, Masitah Ghazali

The natural interaction aspects of the user interface are more significant in the devices of impaired users than the devices of healthy users. This work investigates three controls as the wheelchair controllers according to the design and physicality principles; conventional joystick, isometric joystick, and quad-directional button. Our aim is to provide further ease of use to the impaired whilst strengthening link between embedded software engineering and human-computer interaction. We conclude that an improved multi-function interface design by using Nintendo‘s Wiimote quad-directional button is more intuitive, flexible and natural to use.

519-533

Authors: Fazal-e- Amin, Ahmad Kamil Mahmood, Alan Oxley

Software product lines and open source software are two emerging paradigms in software engineering. A common theme in both of these paradigms is „reuse‟. Software product lines are a reuse centered approach that makes use of existing assets to develop new products. At the moment, a motivation for using open source software is so as to gain access to source code, which can then be reused. The product line community is being attracted to open source components. The use of open source software in software product lines is not for one time reuse but, being a core asset, the component is intended to be used repeatedly for the development of other products in the family. In this paper the results of an exploratory study is presented; it was conducted to explore the factors affecting the reusability of open source components. On the basis of the results of the exploratory study a reusability attribute model is presented which makes use of established object oriented metrics accompanied with newly defined metrics. The assessment using the proposed metrics is compared with the rankings assigned by human evaluators.

542-552

Authors: Bilal Munir Mughal, Asif Ali Wagan, Halabi Hasbullah

Life safety on road is the key motivation behind the research in Vehicular Ad-hoc Network (VANET). As basic communication mechanism VANET-equipped vehicles broadcast periodic safety beacons to keep the neighboring vehicles aware of the situation at all times. Well known broadcast communication problems i.e. hidden/exposed nodes, collisions and inherent challenges in VANET e.g. dynamic environment, limited bandwidth, are prone to hinder the exchange of potentially lifesaving information. Furthermore, the most of vehicle-to-vehicle broadcast communication will comprise of single-hop periodic safety beacons thus it becomes important to measure their Quality of Service (QoS) under congested vehicular environment. With the help of extensive simulations, a detailed analysis is presented to assess the performance of single-hop periodic safety beacons. Parameters i.e. communication range, beacon generation interval and safety beacon size are effective in controlling the QoS levels. The QoS metrics used for the evaluation are packet delivery ratio, per-node throughput, end-to-end delay and Packet loss ratio breakup. Simulation results show that in congested environment it is very difficult to meet the safety application‟s QoS requirements.

565-580

Authors: Muhammad Qaiser Saleem, Jafreezal Jaafar, Mohd Fadzil Hassan

Currently most of the enterprises are using SOA and web services technologies to build their web information system. They are using MDA principles for design and development of WIS and using UML as a modelling language for business process modelling. Along with the increased connectivity in SOA environment, security risks rise exponentially. Security is not defined during the early phases of development and left onto developer. Properly configuring security requirements in SOA applications is quite difficult for developers because they are not security experts. Furthermore SOA security is cross-domain and all required information are not available at downstream phases. Furthermore, business process expert; who is the actual stakeholder of the business process model is unable to specify security objectives due to lake of security modelling elements in a general purpose modelling languages like UML. As a result, business process expert either ignore the security intents in their model or indicate them in textual way. A security intents DSL is presented as a UML profile where security intents can be modelled as stereotypes on UML modelling elements during the business process modelling. Aim is to facilitate the business process expert in modelling the security requirements along the business process modelling. This security annotated business process model will facilitate the architectural team in specifying the concrete security implementation. As a proof of work we apply our approach to a typical on-line flight booking system business process.

599-614

Authors: Sabrina Ahmad, Noor Azilah Muda

Negotiation is one promising effort during requirements elicitation process to improve the quality of software requirements. When negotiation is claimed beneficial theoretically, it is important that the deployment of negotiation is examined and the effectiveness of negotiation is evaluated through empirical study. This paper aims at providing an empirical framework design to examine the improvement in software requirements through negotiation. Besides, it elaborates the relevance of negotiation in requirements elicitation process and its effectiveness. An empirical study method is imposed to design the framework. The design is carefully established based the selection of population and participants, the experimental protocol, threats to validity and justification of measures.

624-639

Authors: Md. Mahedi Hassan, Poo Kuan Hoong

The working group of NetLMM has proposed a new approach, known as network-based mobility management protocol that is actively standardized by Internet Engineering Task Force called Proxy Mobile IPv6 where many mobility signaling messages are performed by a network entity on behalf of a mobile host. Proxy Mobile IPv6 is an effective mobility management protocol for next generation wireless networks that are expected to enable network access ubiquity. Proxy Mobile IPv6 has salient features that attract a lot of attention among the telecommunication and Internet communities. However, Proxy Mobile IPv6 stills suffer from lengthy handover latency and packet loss when Mobile Host moves away to a new network with high speed mobility during the handover process. In order to improve the performance of Proxy Mobile IPv6, we proposed a solution scheme with integration of Media Independent Handover and neighbor discovery message of IPv6 to reduce handover latency and packet loss. But, this proposed protocol does not have methods to prevent security threats such as replay attack and key exposure when mobile host first enters into Proxy Mobile IPv6 domain and also during the handover process. In order to protect this proposed protocol, an authentication method based on the authentication protocol is presented in this paper that can prevent security threats. Also, this authentication method reduces authentication latency.

652-664

Authors: Nurul Haszeli Ahmad, Syed Ahmad Aljunid, Jamalul-lail Ab Manan

Since early 70s, software vulnerabilities have been classified and measured for various purposes including software assurance. Out of many software vulnerabilities, C vulnerabilities are the most common subject discussed, classified and measured. However, there are still gaps in those early works as C vulnerabilities still exist and reported by various security advisors. The most common and highly ranked is C overflow vulnerabilities. Therefore, we propose this taxonomy, which classified all existing overflow vulnerabilities including four vulnerabilities that have never been classified before. We also provide a guideline to identified and avoid these vulnerabilities from source code perspective. We ensure our taxonomy is constructed to meet the characteristics of well-defined taxonomy. We also evaluate our taxonomy by classifying various software security advisories and reports using our taxonomy. As a result, our taxonomy is complete and comprehensive, and hence, is a valuable reference to be used as part of software assurance processes.

683-693

Authors: M Nordin A Rahman, Yuzarimi M Lazim, Farham Mohamed

The huge size of multimedia data requires for efficient data classification and organization in providing effective multimedia data manipulation. Those valuable data must be captured and stored for potential purposes. One of the main problems in Multimedia Information System (MIS) is the management of multimedia data. As a consequence, multimedia data management has emerged as an important research area for querying, retrieving, inserting and updating of these vast multimedia data. This research considers the rough set theory technique to organize and categorize the multimedia data. Rough set theory method is useful for exploring multimedia data and simplicity to construct multimedia data classification. Classification will help to improve the performance of multimedia data retrieving and organizing process.

714-720

Authors: Mehrdad Jangjou, Alireza Bagheri, Mohammad Mansour Riahi Kashani, Koosha Sadeghi Oskooyee

Interference and specially one of the most common kinds of it which is also known as physical interference, is among the most critical problems in terms of multi-robot co-operation. A simple way reducing interference is to make robots remain in unique work areas and move the objects to the next robot as soon as they intersect their areas’ borders. The problem of interference reduction, in this article, was investigated using complex task partitioning in the self-organized robotic swarms. The presented method is simulated, which eliminates some of the previous simulations’ limitations in many domains including the number and robots’ speed. These developments contribute to a more real impression of the natural world problems. The results show improvements in terms of operation cost.

743-756

Authors: Norzaliha Mohamad Noor, Rusli Abdullah, Mohd Hasan Selamat

Early warning system (EWS) is a technology to mitigate risk is used to disseminate timely information. Then knowledge management system (KMS) is used to support for decision facilitation will integrate with EWS to disseminate timely information with proactive early warning. Issues on timeliness for timely reporting and decision facilitation are regarded as main challenge for mitigation of risk. Therefore in this paper, we suggest the model of integration between KMS and EWS known as KMS@EWS as a solution to support early warning for timely reporting and to guide on decision facilitation. The integration model is to combine the knowledge management (KM) processes, activities and technologies with the EWS functionalities. The proposed model is based on empirical study by using literatures on EWS and KMS. In which we synthesize the analysis and findings of both EWS and KMS for the integration. We propose the implementation model in clinical diagnostic (CD) environment of dengue fever (DF) manifestation. This model is intended to provide early warning when any abnormalities or peculiar pattern of DF and symptoms arise and detected during the interaction between physicians and patients in the CD environment. Thus, this paper attempts to integrate relevant enabling KM technologies and processes with EWS components and functionalities into an environment that would support activities for early warning thru organizational knowledge creation, use and management for timely reporting and detection by providing decision facilitation and initiate early warning of DF during CD processes.

766-779

Authors: Zul Hilmi Abdullah, Nur Izura Udzir, Ramlan Mahmod, and Khairulmizam Samsudin

File is a component of a computer system that has importance value of its own, either in terms of availability, integrity, confidentiality and functionality to a system and application. If unintended changes happen on the related file, it may affect the security of related computer system. File integrity monitor (FIM) tools is widely used to minimize the file security risk. This paper proposed dynamic schedule for FIM. This paper presents a dynamic scheduling for FIM by combining on-line and off-line monitoring based on related files security requirement. Files are divided based on their security level group and integrity monitoring schedule is defined based on related groups. The initial testing result shows that our system is effective in on-line detection of file modification.

257-264

Authors: Ebtehal Alsaggaf, Prof.Dr. Fathy albouraey

The concept of building the best component-based application becomes very attractive. But, the reusable components must comply with specific underlying middleware architecture in order to interact with each other efficiently. This dependency on the underlying architecture creates compatibility problems. Anyway, software agents provide a powerful new method for implementing the information systems. Multi-Agent System (MAS) can communicate and cooperate with each other to solve complex problems and implement complex systems. So, in this research, we will define how component CORBA can interact with DCOM by using MAS. This will able to make us freedom to choose the best attributes from both systems and combine them to build the best possible application that specifically suits my environment.

275-281

Authors: Hoshang Kolivand, Mohd Shahrizal Sunar

In this paper two techniques of shadow generation are described. Volume shadow is geometric base but shadow mapping is image base. Silhouette detection is a most expensive step to create volume shadow. Two algorithms to recognize silhouette are introduced. Stencil buffer and Z- buffer are two other tools for creating shadow by volume shadow technique. Both algorithms are implemented in virtual environment with moveable light source. Triangular method and the Visible-non visible method are introduced. The recent traditional silhouette detection and implementation techniques used in volume shadow algorithm are improved. With introduce flowchart of both algorithms, the last volume shadow algorithm using stencil buffer is rewritten. A very simple algorithm to create volume shadow is proposed. The last shadow mapping algorithm is rewritten. These techniques are poised to bring realism into commercial games. It may be use in virtual reality applications.

292-303

Authors: Bogart Yail Márquez, Manuel Castañon-Puga, Juan R. Castro, Eugenio D. Suarez, José Sergio Magdaleno-Palencia

This work has as its main objective to apply the distributed agency methodology, which consists of several techniques used in computer science, to solve complex social problems. This approach allows the possibility of analyzing data from a macro level to a micro level where the intermediate part is highlighted, all in an organized integration of a social simulation displayed on geographic information with natural language quantifiers. We present a new model based on Distributed agencies Model and we use an interval type-2 fuzzy logic system is designed to evaluate the poverty levels.

316-324

Authors: Ta- Te Lu, Tsung-Hsuan Tsai, Jia-Yuan Wu

Video quality retrieval is an important issue in reconstruction video sequences. The amounts of transmission bitstreams are very large to achieve high video quality reconstruction. Thus, high video quality retrieval is still a challenge problem. The aim of this paper is to reduce the transmission bitstreams and raise reconstruction video quality. In this paper, we propose a scalable block compensation with index selection mechanism using eigenvalue and local variance statistics for each group of pictures (GOP), which are regarded as the feature parameters for compensating motion blocks for each video frame from low-resolution to high-resolution sequences at the receiver ends. To reduce transmission overhead, the index selection technique is then applied to those selective compensation blocks to have variances larger than a threshold. The results of index numbers from index selection are regarded as reconstruction information. Simulation results show the percentage of noncompensation blocks is nearly 30% saving for Mobile, 36% saving for Foreman, and 48% saving for News. These results indicate that the proposed algorithm offers a more efficient way to decrease the percentage of compensation blocks about 30~48%. The proposed algorithm, on average, outperforms H.264/AVC about 2.8~9.8 dB from 100 kbps to 1 Mbps.

336-343

Authors: Kamarularifin Abd. Jali, Zaid Ahmad, Jamalul-Lail Ab Manan

Ad hoc On Demand Vector (AODV) is a reactive routing protocol in Mobile Ad hoc Network (MANET). Although the protocol has been around for quite some time, but there is still security issue which made it vulnerable to various attacks such as black hole which tremendously affects the network performance. There have been several works done to mitigate this problem but most of the proposed methods introduce overhead to the existing protocol i.e. extra control messages. Most of MANET devices are resource constraint and therefore a light solution is needed. For this reason, in this paper we proposed a method called ERDA (Enhance Route Discovery for AODV). The proposed method is able to mitigate the aforesaid problem by introducing new conditions in the routing table update process and also by adding simple malicious node detection and isolation process to the AODV route discovery mechanism. The proposed method does not introduce any additional control message and moreover, it does not change the existing protocol scheme. In order to test the proposed method, a simulation model was developed. The simulation results show significant improvement to the network performance after ERDA is implemented in the AODV as compared to the existing AODV protocol.

358-370

Authors: Hu Ng, Hau-Lee Ton, Wooi-Haw Tan, Timothy Tzen-Vun Yap, Pei-Fen Chong, Junaidi Abdullah

This paper presents a human identification system based on automatically extracted gait features. The proposed approach consists of three parts: extraction of human gait features from enhanced human silhouette, smoothing process on extracted gait features and classification by three classification techniques: fuzzy k- nearest neighbour, linear discriminate analysis and linear support vector machine. The gait features extracted are height, width, crotch height, step-size of the human silhouette and joint trajectories. To improve the classification performance, two of these extracted gait features are smoothened before the classification process in order to alleviate the effect of outliers. The proposed approach has been applied on SOTON covariate database, which comprises eleven subjects walking bidirectional in a controlled indoor environment with thirteen different covariate factors that vary in terms of apparel, walking speed, shoe types and carrying objects. From the experimental results, it can be concluded that the proposed approach is effective in human identification from a distance over various covariate factors and different classification techniques.

384-395

Authors: Fazli Bin Mat Nor, Kamarularifin Abd Jalil, Jamalul-lail Ab Manan

Most remote authentication schemes use key exchange protocol to provide secure communication over an untrusted network. The protocol enables remote client and host to authenticate each other and communicate securely with prearranged shared secret key or server secret key. Many remote services environment such as online banking and electronic commerce are dependent on remote authentication schemes to validate user legitimacy in order to fulfill the authentication process. Unfortunately, these schemes are not able to provide trust or evidence of claimed platform identity. Therefore, these schemes are vulnerable to malicious software attacks that could compromise the integrity of the platform used for the communication. As a result, user identity or shared secret key potentially can be exposed. In this paper, we present a remote authentication scheme using secure key exchange protocol with hardware based attestation to resist malicious software attack. In addition, a pseudonym identity enhancement is integrated into the scheme in order to improve user identity privacy.

404-411

Authors: Rosmayati Mohemad, Abdul Razak Hamdan, Zulaiha Ali Othman, Noor MaizuraMohamad Noor

Portable Document Format (PDF) is the most comfortable way to publish information because of its operating system independent. However, information on PDF document is unstructured and are applicable only for human reader. In addition, PDF consists of non-tagged internal structure which make the extraction task difficult. Automatically details analyzing and recognizing of PDF document structures especially paragraph and tabular area is vital for extracting relevant information precisely for use in other domain applications. Motivation of this study is to support knowledge extraction and exploit its actual semantic for improving further analysis. This paper proposed an intelligent approach to identify and recognize automatically the layout and structure of PDF documents together with their text and then structure the extracted information into ontological- based representation. An experimental study has been conducted using a collection of construction tender documents in PDF to test the performance of the proposed approach. The accuracies of precision, recall and f-measures have shown significant results when detecting tabular and paragraph structure.

428-436

Authors: Siti Z. Z. Abidin, Nasiroh Omar, Muhammad H.M. Radzi and Mohammad B.C. Haron

Currently, an online forum is becoming one of the trends in social media. Social media allow people to communicate interactively so they can share their feelings and opinions. Even though, they are communicating through text, such digital element permits them to express their emotions. The information that is conveyed through texts has the potential to influent people’s mind sets. In this paper, we propose to quantify people’s perception in an online forum by analyzing their words. The number of occurrences for significant words is counted in order to measure their perception based on emotion and issues that they are discussing. This new approach significantly reduce the time for collecting, processing, and analyzing data, as well as visualizing results, specifically for seeking public’s perception and emotion of specific issues.

459-473

Authors: Rozmie R. Othman, Kamal Z. Zamli

The adoption of t-way strategies (also termed interaction testing) for combinatorial testing is the main focus of this paper. Unlike earlier work, this paper unifies the different possible use of t-way strategies including uniform interaction, variable strength interaction, and input output based relations. In order to help engineers make informed decision on the different use of t- way strategies, this paper highlights the current state-of-the-art on different t-way strategy implementations. In doing so, this paper also discusses a step-by-step example as practical application.

484-489

Authors: Nurul Asyikin Mohamed Radzi, Norashidah Md. Din, Mohammed Hayder AlMansoori, Mohd. Shahmi Abdul Majid

In order to accommodate the needs of very high-speed broadband access, the most attractive solution that is being used nowadays is Ethernet passive optical network (EPON). In upstream EPON, dynamic bandwidth allocation (DBA) algorithm is needed to avoid collision. By ensuring global priority inside DBA, bandwidth can be better utilized since we grant the upstream bandwidth to each queue according to the priority. In this paper, we analyze the delay performance of global priority DBA algorithm proposed that we called as EDBAGP and compare it to EDBA and Min’s DBA algorithms. We vary the number of ONUs to 16 and 32. We can see that EDBAGP can improve as high as 25.22% for 16 ONUs and 41.35% for 32 ONUs as compared to Min’s DBA. It can also improve as high as 20.69% compared to EDBA for 16 ONUs and 28.57% for 32 ONUs.

510-518

Authors: Alfi Khairiansyah Machfud, Abdul Rahman Ahmad Dahlan, Jawdat Khatib, Ahmed Abdulaziz Haji-Ahmed

This paper takes the form of a general review. It introduces the notion of government-industry collaboration and information sharing in the Halal industry that work together for achieving common goals such as in economic, health, environmental, and social well-being– moving towards making living more meaningful, productive, fruitful and profound. Technological empowerment –in particular inter-organizational information systems (IS) and information sharing– is regarded as the key driver for supporting a sustainable economic development at the global, regional and local levels. Through IS, it is viable and essential to establish a global knowledge base, shared, used, enhanced and contributed to by a variety of experts and professionals throughout the world in different fields toward achieving common goals. The paper raises awareness of relevant government-industry collaboration initiatives, leveraging on the strategic use of IS to promote individual and community growth as well as to facilitate sustainable development. As there are five main components of an IS –hardware, software, data, procedures/processes, and people– this also mean that many different skills and effective change management programs are required to ensure users’ acceptance, leadership commitment and business processes between organizations are improved in ensuring ISs are effective in delivering the business goals of participating partners and collaborators.

1-14

Authors: Salah I. Al-Mously

This paper presents a procedure for the evaluation of the Electromagnetic (EM) interaction between the mobile phone antenna and human body, i.e., head and hand, and investigates the factors may influence this interaction. These factors are considered for different mobile phone handset models, different form factors and different antenna types, operating in the GSM900, GSM1800/DCS, and UMTS/IMT- 2000 bands. A realistic usage of mobile phone handset next to head at cheek and tilt positions, in compliance with IEEE-standard 152, is considered during computations. Homogeneous and heterogeneous CADmodels are used to simulate the mobile phone user’s head, whereas, a homogeneous model with three different tissues is designed to simulate the user's hand-hold. A validation of our EM interaction computation using both Yee-FDTD and ADI-FDTD is achieved by comparison with previously published works.

25-33

Authors: Hassina Bensefia, Nacira Ghoualmi

Computer Forensics applies law to fight against unlawful and illegitimate use of computers and networks. It employs investigation methods to solve computer crimes. Knowing that the firewall is the unique input and output in a network, it is considered as the ideal location for recording network activities. The firewall log files trace all incoming and outgoing events in a network. Its content can include details about attacks and penetration attempts in the network. For this reason firewall forensics becomes a principal branch in computer forensics field. It uses the firewall log files content so as a source of evidence to lead an investigation in the aim to identify computer attacks. The investigation in firewall forensics consists of analyzing and interpreting the relevant information related to computer attacks which is contained in firewall log files. But the log files content is generally mysterious and difficult to decode. Its interpretation requires a qualified expertise. This paper proposes an intelligent system that automates the firewall forensics process and helps the security administrator to manage, exploit and interpret the firewall log files content. This system will assist the security administrator to make suitable decisions and judgments during the investigation step.

52-60

Authors: Mona Nafari, Mansour Nejati Jahromi, Gholam HoseinSheisi

In this paper, a reversible data hiding scheme has been proposed which is based on correlation of subsample images. The proposed method modifies the blocks of subsampled image to prepare vacant positions for data embedding. The PSNR of the stego image produced by the proposed method is guaranteed to be above 47.5 dB, while the embedding capacity is at least, almost 6.5 times higher than that of the Kim et al. techniques with the same PSNR. This technique has the capability to control the capacity-PSNR. Experimental results support that the proposed method exploits the correlation of blocked sub-sampled image, outperforms the prior works in terms of larger capacity and stego image quality both. On various test images, we demonstrate the validity of our proposed method by comparing to other existing reversible data hiding algorithms.

74-83

Authors: Othman Mohd Yusop, Suhaimi Ibrahim

Software Maintenance Testing is essential during software testing phase. All defects found during testing must undergo a re-test process in order to eliminate the flaws. By doing so, test cases are absolutely needed to evolve and change accordingly. In this paper, several maintenance testing approaches namely regression test suite approach, heuristic based approach, keyword based approach, GUI based approach and model based approach are evaluated based on software evolution taxonomy framework. Some of the discussed approaches support changes of test cases. Out of the review study, a couple of results are postulated and highlighted including the limitation of the existing approaches.

97-111

Authors: Gontlafetse Mosweunyane, Leslie Carr, Nicholas Gibbins

Computer systems provide users with abilities to create, organize, store and access information. Most of this information is in the form of documents in files organized in the hierarchical folder structures provided by operating systems. Operating systemprovided access is mainly through navigation of the file hierarchy, and through keyword search. An investigation with regard to access and utilization of these documents revealed a need to reconsider these navigation methods. An improved method of access to these documents is proposed based on previous effective metadata use in search system-retrieval and annotation systems. The underlying organization is based on a model for navigation whereby documents are represented using index terms and associations between them exposed to create a linked, similarity-based navigation structure. Evaluation of an interface instantiating this approach suggests it can reduce the user’s cognitive load and enable efficient and effective access and navigation of the file hierarchy. This is enabled by provision of keywords as reminders for discovering and associating documents.

123-132

Authors: Faiza Mekhalfa, Daoud Berkani

Based on the standard fractal transformation in spatial domain, simple relations may be found relating coefficients in detail subbands in the wavelet domain. In this work we evaluate a hybrid wavelet-fractal image coder, and we test its ability to compress radiographic images of weld defects. A comparative study between the hybrid coder and standard fractal compression technique have been made in order to investigate the compression ratio and corresponding quality of the image using peak signal to noise ratio. Numerical experiments using radiographic images of weld defects illustrate the superior performance of the hybrid coder compared to standard fractal algorithm.

149-161

Authors: Sofiane Hamrioui, Mustapha Lalam

In this paper, we propose an improvement to the transport protocol performance in Mobile Ad Hoc Network (MANET) by exploiting the backoff algorithm of Medium Access Control (MAC) protocol. We are especially interested in the TCP (Transmission Control Protocol) performance parameters like the throughput and end-to-end delay. This improvement is IB-MAC (Improvement of Backoff algorithm of MAC protocol) which proposes a new backoff algorithm based on a dynamic adaptation of its maximal limit according to the number of nodes and their mobility. The evaluation of our IB-MAC solution and the study of its incidences on TCP performance are done with AODV as like routing protocol, TCP New Reno as like transport protocol and varied network conditions such as load and mobility. The results are satisfactory and showed that our algorithm can outperform not only MAC standard, but also similar techniques that have been proposed in the literature like MAC-LDA and MAC-WCCP.

176-184

Authors: Malinka Ivanova, Georgi Ivanov

In this paper the experience gained at using low-cost interactive marker augmented reality (AR) technology during course Computer graphics is presented. The preliminary exploration of AR technology adoption for teaching support and learning enhancement is done and several benefits are identified, summarized and analyzed via a model. Two learning scenarios are designed based on human-computer interaction principles to present important concepts virtually in interactive and engaging way. The students’ opinion is gathered and the results describe AR as promising and effective technology that allows better understanding of theory and facts and that supports creative thinking and development of more realistic 3D models and scenes.

199-208

Authors: Khalil Challita, Hikmat Farhat

Our main goal in this paper is to give new insights and directions on how to improve existing methods of hiding secret messages, possibly by combining steganography and cryptography. We start by describing the main existing methods and techniques in steganography that allow us to hide the existence of a message, together with the mostly used steganalysis techniques to counter them. We then illustrate two different approaches that help us achieve a higher level of secrecy and security, together with their limitations. The first method is about combining steganography and cryptography in such a way to make it harder for a steganalyst to retrieve the plaintext of a secret message from a stego-object if cryptanalysis were not used. The second method does not use any cryptographic techniques at all and relies solely on steganographic ones.

223-235

Authors: T. taniguchi, Y. Karasawa, N. Natajima

Block diagonalization (BD) technique is widely used in multiple input multiple output (MIMO) multiuser downlink systems because of its simplicity and high ability for eliminating the interuser interferences. In this study, very simple weight design algorithms based on BD are proposed, in which the order of steps is swapped, namely, receiver weights are calculated first, and then transmisson weights are derived using zero forcing (ZF) approach. It is shown through computer simulations that the proposed method achieves better performance that the conventional BD under certain conditions. Additionally, the condition on the degrees of freedom is released, hence it can be utilized for the transmitters with small number of antennas to which BD cannot be applied.

245-256

Authors: Gianni Fenu, Marco Nitti

The aim of this paper is to find the best strategies to carry and forward packets within VANETs that follow a Delay Tolerant Network. In this environment nodes are affected by intermittent connectivity and topology constantly changes. When no route is available and the link failure percentage is high, the data must be physically transported by vehicles to destinations. Results show how, using vehicles cooperation and several carry and forward mechanisms with different deliver priorities, is possible to improve performance for free in terms of data transmissions. In our experiments we use realistic traffic data obtained by multi-agent traffic simulator and also study which are the best conditions to apply our mechanism in an everyday scenario.