This paper proposes a novel image tracking technique for the image-based positioning study on the mobile device. The study uses the panorama as the indoor map to localize the user. Since the number of feature points of the panorama is much larger than feature points from the image of the mobile device, the performance of matching mobile device image with the panorama will significantly affect the efficiency of the positioning. Hence, a Sorting Hat approach is proposed to filter out uncorrelated feature pairs as early as possible. The Sorting Hat is designed according to the characteristic of BRISK which is adopted as feature detection technique in this study. However, since the coordinates of the panorama is not the same as that of mobile device image, a coordinates unification is proposed to improve the effectiveness of image matching. To further improve the image matching speed during the positioning process, a Reckon-View mechanism on the panorama is also proposed. Our experiments show that the Sorting Hat approach can decide if two feature points are correlated within 0.824ms at 99.6% confidence. Furthermore, the experiment also prove that the Reckon-View mechanism can reduce the number of feature pairs computation to two-thirds of the original.

Most visual applications rely on matching keypoints between two images. Due to the physical constraints of embedded devices, a descriptor with high accuracy and low memory is preferred for visual applications on mobile devices. Fast Retina Keypoint (FREAK) are known as the fastest descriptor nowadays with robustness on scale, rotation and noise. Based on the sampling points of FREAK, this paper proposes a new descriptor, RETOP, that has similar matching effectiveness as FREAK with three times faster speed. RETOP is designed according to the topography of ganglion cell density map of human retina and earn its name accordingly. Benefit from RETOP's well symmetrical structure, our experiment shows that RETOP is more efficiency than FREAK in the change of environments. Hence, RETOP make the realization of real-time visual application on mobile device on step further.

We identified an important issue when supporting a large scale networked virtual environment (NVE) with a server cluster. This issue is similar to the process migration issue on the parallel computing study and we refer it as the avatar migration problem. That is, when an avatar of an NVE is moving from one region managed by a server to another region managed by a different server, the client site may perceive abrupt screen change due to the different contents managed by these two servers. This paper proposes equations to solve this problem and elaborates the proposed avatar migration mechanism with state diagrams. The implementing architecture is also given in this paper. Our experiments that successfully show the efficiency of the proposed mechanism are given at the last.

Locomotion is a virtual reality interface that enables the user to walk inside the virtual environment in any direction over a long distance without actually leaving the physical device. In order to enable the user to freely navigate the virtual world and get fully immersed into the virtual environment accordingly, a locomotion device must fulfill the following two distinct requirements. First, it should allow the user to navigate an infinite distance within a limited area. Secondly, the user should not need to wear any tracking devices to detect his motion. The paper presents a locomotion mechanism called omni-directional ball-bearing disc platform (OBDP), which allows the user to walk naturally on it and thus to navigate the virtual environment. The gait sensing algorithm that simulates the user's posture based upon his footstep data collected from the OBDP is then elaborated. Followed with an omnidirectional stroll-based virtual reality system to integrate the OBDP with the gait sensing algorithm. Significantly, instead of using the three-dimensional (3-D) tracker, the OBDP adopts arrays of ball-bearing sensors on a disc to detect the pace. No other sensor, except the head tracker to detect the user's head rotation, is required on the user's body. Finally, a prototype of an overhead crane training simulator that fully explores the advantage of the OBDP is presented along with the verification of the effectiveness of the presented gait sensing algorithm.

Electronic activities are realized on the Internet due to the growth of the Internet. As conference organization is getting more popular, we proposed an electronic virtual conference system (EVCS) to handle all activities of real-world conferences. The EVCS includes a virtual conference management system (VCMS) and a mobile conferencing system (MCS). Video conferencing is a trend of future communications. With the improvement of broadband network technologies, video conferencing becomes possible in the global society. It is feasible to use video conferencing technologies to organize future international conferences. As such, transportation and accommodation costs are saved. This paper proposed a total solution toward virtual conferencing. We use a mobile server/storage pre-broadcasting technique, as well as a communication network optimization algorithm, which is based on a graph computation mechanism. The system also relies on a network bandwidth reservation facility as well as a multicasting control function. With the assistance of the virtual conference management system, the system is able to support virtual conferencing in the future academic society.

With the enormous use of networks, many real-world activities are realized on the Internet. We propose a complete virtual conference system (VCS) to handle all activities of real-world conferences. The VCS includes a virtual conference management system and a mobile virtual conference system. Video conferencing is a trend of future communications. With the improvement of broadband network technologies, video conferencing becomes possible in the global society. It is feasible to use video conferencing technologies to organize future international conferences. This research proposes a total solution toward virtual conferencing. We use a mobile server/storage pre-broadcasting technique, as well as a communication network optimization algorithm, which is based on a graph computation mechanism. With the assistance of a conference management system, the system is able to support virtual conferencing in the future academic society.

The design, implementation and experimental results of a multiple-user 3D web-browsing system, called the SharedWeb system, are described in this paper. The system is based on the request–response method of the WWW server. The key features of this system include the ability of the WWW server to remember all the browsers connected to it in order to transmit the messages required to maintain consistent states among browsers. The dead-reckoning technique of distributive interactive simulation (DIS) is used by browsers in order to reduce the number of messages sent onto the network and to satisfy the timing requirement demanded by the virtual environment. The protocol data unit (PDU) defined in DIS is also adapted by the SharedWeb system not only to communicate information among browsers but also to integrate with the DIS environment in the near future. © 1998 John Wiley & Sons, Ltd.

Describes the design implementation and experimental results for a multi-user 3D World Wide Web (WWW) browsing system called SharedWeb, which is based on the request-response method of a WWW server. The key features of this system include: (i) the WWW server's ability to remember all the browsers connected to it in order to transmit those messages required to maintain consistent states among the browsers, (ii) the dead-reckoning technique of distributed interactive simulation (DIS) used by the browsers in order to reduce the number of messages sent out on the network and to satisfy the timing requirement demanded by virtual environments, and (iii) the protocol data unit (PDU), also used in DIS, adapted by the SharedWeb system in order not only to include more information about the browsers but also to integrate SharedWeb with DIS in the near future.