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Science and, Saudi Arabia

Zarrad A.,Prince Sultan University | Bensefia A.,Imam Muhammad Bin Saud University
2013 9th International Conference on Innovations in Information Technology, IIT 2013

Modern Collaborative Virtual Environments (CVEs) are no longer developed as a one-piece to support specific applications such as online games, Virtual shopping, and E-health. In the traditional way, any modifications in VE applications require a service interruption in order to change both programming code and the supporting structure. As a consequence the ability to build and/or extend 3D VEs during the runtime becomes tedious task and requires long development time with advanced programming knowledge. Nowadays, it is important to offer an easy and rapid way for users and game developers to build and/or to extend CVE applications during the runtime without having the option to interrupt the system. In this paper, we propose a novel dynamic approach based on event atomic actions management, thanks to the state machine. We employ two different high-level scripting abstractions called class modeling and instance modeling. Class modeling controls what seems to be the simulation scenario, while, instance modeling controls objects and avatars behaviors in the virtual environment. Both class and instance modeling are implemented as a scripting plug-in and mastered respectively by atomic simulation and atomic behavior concepts. The atomic behavior concept is not only limited to object behaviors, it also handles the avatar facial animation parameters as defined in MPEG-4 SNHC standard. We evaluate the benefits of our proposed solution by describing a complex firefighter's game scenario. Through this scenario we explore the interaction between class and instance script modeling as well as the implication of atomic concepts on making code writing, when a VE application modification is required. © 2013 IEEE. Source

Piao Y.,Ajou University | Kim J.,Ajou University | Tariq U.,Imam Muhammad Bin Saud University | Hong M.,Ajou University
Computers and Mathematics with Applications

Secure group communication has become an important issue in many applications. Both intra-group and inter-group multicast traffic must be protected by shared secret keys. In order to communicate securely in the same group and among different groups, we employed a polynomial P to achieve efficient intra-group key refreshment and generated a polynomial H(x) to create an inter-group key. Proposed polynomial-based key management schemes have the following advantages: (1) Group members and the group controller can share the intra-group key without any encryption/decryption. (2) When the members of the group get changed, the group controller needs to update and distribute the renewed group keys. The proposed mechanism can reduce the number of re-keying messages. (3) The proposed mechanism lessens the storage overhead of group members and the group controller by adopting a polynomial-based key management scheme. (4) As compared with previous approaches, the group controller does not need to broadcast heavy messages which are necessary for creating an inter-group key. Hence, it introduces only a small amount of broadcast traffic to the group members. The analysis of the proposed mechanism is conducted to demonstrate the improvements. © 2012 Elsevier Ltd. All rights reserved. Source

Alhaidari I.S.,Imam Muhammad Bin Saud University | Yani-de-Soriano M.,University of Cardiff | Yousafzai S.Y.,University of Cardiff

The theory of reasoned action (TRA) and the theory of planned behavior (TPB) have been found to have predictive capability in a wide range of personal behaviors. The aim of the study is twofold: firstly, to assess the applicability of the TRA, the TPB, and a newly developed revised version of the TPB in the context of individuals’ monetary donations to charitable organizations; and secondly, to compare the explanatory and predictive power of these three theoretical models. Data relating to intention to give monetary donation, attitudes toward helping others and toward charitable giving, social norms, moral responsibility, and perceived behavioral control were collected in the first phase of the study by means of a self-completion mail questionnaire distributed to 432 residents of Riyadh, Saudi Arabia. In the second phase, 1 month later, telephone interviews were conducted with 221 of the first-phase respondents who had agreed to take part in a follow-up survey of their actual monetary-donating behavior. The findings show that the revised TPB is the best of the three models for predicting individuals’ intention to donate and their future monetary-donation behavior, mainly because moral responsibility is included in the theoretical framework. It thus offers superior explanatory and predictive power. © 2016 International Society for Third-Sector Research and The Johns Hopkins University Source

Elarbi-Boudihir M.,Imam Muhammad Bin Saud University | Rehman A.,Imam Muhammad Bin Saud University | Saba T.,Imam Muhammad Bin Saud University
International Journal of Physical Sciences

Motion estimation in image sequences is a fundamental issue in many applications as for instance in artificial vision and three-dimensional scene reconstruction. The basic problem of the recent spatiotemporal filtering techniques used in the perception of object motion from a time sequence of 2-D images is the computational burden. This is mainly due to the computation of the frequency responses of the images to the Gabor filters using the multi-resolution approach. In this paper we present a method for detecting and estimating object motion using spatio-temporal frequency information from image sequence. Our model of visual perception of object motion from a video stream is based on a contributory adaptation of spatiotemporal Gabor filters. This method uses a bank of Gabor filters which are frequency tuned and limited in spatial extent. Instead of testing the entire filter bank to determine the appropriate filter parameters, a genetic algorithm is used to derive the filter subset that provides the object texture information and optimize the search for its perceived motion. This model has been evaluated on artificial as well as natural image sequences. The results obtained show the feasibility of the approach which attains a reasonably fast output rate (several images/second) for a better resolution. ©2011 Academic Journals. Source

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