Today’s wireless networks are characterized by fixed spectrum assignment policy. The limited available spectrum and the inefficiency in the spectrum usage necessitate a new communication paradigm, referred to as Dynamic Spectrum Access (DSA) and cognitive radio networks. The dynamic spectrum access technology can allow unlicensed secondary systems to share the spectrum with the licensed primary...

Single data replica management strategy can not meet the complexity and diverseness in data grid. This paper proposes a dynamic self-adapting replica management architecture (DSA-RM) driven by software architecture (SA). In DSA-RM, architecture descriptions are shared by the whole grid environment as a system kernel to schedule various replica management components that are adapted to various a...

While threshold signature schemes have been presented before, there has never been an optimal threshold signature algorithm for DSA. Due to the properties of DSA, it is far more difficult to create a threshold scheme for it than for other signature algorithms. In this paper, we present a breakthrough scheme that provides a threshold DSA algorithm that is efficient and optimal. We also present a...

Like most common natural resources, spectrum is finite and prone to overuse and “crowding”. Most of today’s radio systems are not aware of the spectrum environment and operate in a pre-given, static frequency band. Technologies such as cognitive radio (CR) that enable dynamic spectrum access (DSA) have been proposed to improve efficiency and flexibility in the utilization of spectrum. Such tech...

higher education plays a very vital role in developing human resources as well as economic ones in every country. in so doing, the act of evaluation would help the decision makers as well as managers to spot the weaknesses to use the required provisions to work more effectively. the present study with a different approach toward the designing a comprehensive evaluation expert system using fuzzy...

Society is often guilty of taking our buried utilities for granted. However, just like every other type of infrastructure, their neglect can have catastrophic effects. Therefore urgent attention is needed in order to facilitate and improve upon the current buried utilities maintenance techniques. The underground world is sometimes denser than the above-ground world. A classic example of this is...

This paper explores domain arguments—arguments about why techniques, processes, and designs possess properties as believed by their domain experts. An elicitation technique for their recovery from domain documents is presented. This is followed by demonstrated application of the technique to several domain artifacts from aviation engineering. The elicited arguments are presented and analyzed fo...

In this report, we describe the design of a comprehensive eHealth system that offers a range of services allowing patients or elderly people to receive necessary care in the home setting. The system architecture allows home assistance to be offered by commercial entities, thus propelling its deployment. Since home assistance systems often have to handle sensitive medical information, protection...

An imposing number of lossy compression techniques used in medicine, represents a challenge for the developers of a Picture Archiving and Communication System (PACS). How to choose an appropriate lossy medical image compression technique for PACS? The question is not anymore whether to compress medical images in lossless or lossy way, but rather which type of lossy compression to use. The numbe...

although allameh majlisi has not intended to write a distinct ethical book on ethics or to present a coherent moral system in various volumes of behar al-anwar, but we can deduce a comprehensive ethical system through examination of the different discussions he has made about different  verses and traditions. this deduced ethical system not only emphasizes the role of reason in explaining the t...