Earticle

Context-awareness has been recognized as an important enabler for pervasive computing. Our aim is to provide a thorough survey of the state of the art in context representation and reasoning in the field of pervasive and context-aware computing. The review is organized in sections according to the knowledge representation techniques applied in the work included in the survey and an overview of the requirements for context representation is provided. We conclude the paper with a discussion of a number of identified limitations in the current solutions and point out opportunities for further research.

An important QoS factor for wireless network planning is delay. We should provide enough resources (bandwidth) for conveying the traffic load. Next generation wireless networks is going to be an all IP network. In this path, voice will be changed to packet. In this paper we introduce a queuing model and a radio resource management algorithm which maximize the system throughput (users), then compute their delays and show this delay is less than the mentioned delay in the 3GPP standards.

This paper describes a context extraction framework for a mobile device that equips a variety of sensors. The framework captures context about a user and her surrounding environment; the information is used to adapt the behavior of applications running on the mobile device. Our framework adopts the blackboard architecture to execute multiple analysis modules that analyze signals from respective sensors. Respective modules implement different algorithms to complement each other's results to retrieve accurate high-level context. Based on experiments with a sample application, we evaluate the feasibility of the framework and point out the possibilities and limitations of context extraction in mobile devices.

Due to the extensive availability of wireless internet connectivity and low cost light weight mobile devices, an omnipresent customizable service is not a vision anymore. With enhanced wireless connectivity, the handheld mobile devices (PDA, smart phone, cell phone, etc.) can act as a digital personal secretary, being employed in all aspects of life for the purposes ranging from accessing wide range of information to performing various types of activities with greater ease and comfort. If this type of service can be made a reality, it can be used by different types of users in different fields such as education, tourism, shopping or business, at any time and at any place. Here we present Ubiquitous Secretary, which is designed and developed to accomplish the above objectives. Ubiquitous computing applications developed so far are all independent and rich in their own domains but they suffer from the problem of non-inter operability and non scalability. Ubiquitous Secretary is developed upon the web services architecture that easily solves the interoperability and adaptability problem between different ubiquitous computing applications. We developed a prototype and presented how the implementation of the prototype satisfies the characteristics and features of Web Service based architecture.

Literature review revealed that, “Color Queuing Theory” (CQT) was applied for analyzing the variation of color intensity of surfaces of moving objects, studying the surface texture of solids etc. An attempt is made in this paper to investigate the application of CQT for Visual Computing (VC) of attributes of Geometric Solids like straight lines, planes, solids etc and its Engineering Applications. The computed values obtained under the current method and the corresponding values obtained under the conventional method using the theoretical values to investigate the effectiveness of the current method.