This paper discusses a computer vision based approach for enhancing a common device (display) with machine perception capabilities. Using techniques for assessing the distance and orientation of a target from the camera, a “smart device” becomes aware about user’s presence and his interaction intentions. In other words, the “smart device” is aware when it becomes the user’s focus of attention a...

Multi-server architecture is very popular in Distributed Virtual Environments. Although multi-server architecture has good scalability, the load balance and consistency are still challenging issues. Because of server resource limitations (computation, communication etc), the consistency of the virtual world cannot be guaranteed sometimes. In this paper, we address this problem by developing sch...

Cooperation between entities in e-business environments is based on trust; therefore trust is an essential precondition for every e-business transaction. Trust is too often treated as a hard security mechanism, which can fail when agents act deceitfully. Trust is a personal and subjective phenomenon and has to be treated accordingly. This especially holds true for emerging service oriented arch...

In this paper, we propose a framework of personalized information retrieval system for a wearer (a person who is equipped with a wearable computer) in ubiquitous computing environments. In ubiquitous computing environments, personalized information retrieval is indispensable for a wearer because desired or undesired information will be flooded around the wearer. Although there have been many re...

Virtual reality (VR) learning environments can provide students with concepts of the simulated phenomena, but users are not allowed to interact with real elements. Conversely, augmented reality (AR) learning environments blend real-world environments so AR could enhance the effects of computer simulation and promote students’ realistic experience. However, AR-based learning environments had a l...

Grid users always expect to meet some challenges to employ Grid resources, such as customized computing environment and QoS support. In this paper, we propose a new methodology for Grid computing – to use virtual machines as computing resources and provide Virtual Distributed Environments (VDE) for Grid users. It is declared that employing virtual environment for Grid computing can bring variou...

Abstract: This article presents a sensor-based path planner for mobile robots with the robot size and sensing uncertainties directly incorporated into the planning functions. The obstacle boundary is represented as a numbered set of distance sensing data rather than an analytical expression. Referring to the robot size and sensing uncertainties, the path safety and blocking boundaries are analy...

In this paper an overview of the reported parameters of the Ultra Wide Band (UWB) indoor wireless channel is presented. First, an introduction to UWB technology as well as UWB wireless channels is provided. Then, impulse response model for the wireless indoor channel is introduced. The available UWB channel measurements results in indoor environments are consulted and accordingly, the major UWB...

This study concerns the application of tools and methods of Open and Distance Learning (ODL) in the traditional class. More concretely, the design of an instructional aid called «lesson sheets» is discussed, according to specific guidelines, which evolve from the corresponding educational theories. Accordingly, the application of the proposed tool in four classes is described, as perceived by t...

Virtual worlds and animated computer avatars are becoming more realistic, more natural, and more widespread. Accordingly, we are looking at new ways of interacting with machines based on “old” methods for interacting with humans, such as talking, writing and gesturing. By applying a synergistic, multimodal approach to several application domains that incorporate avatars, augmented reality or vi...