Catálogo de publicaciones - libros

The TPR*-tree is the most widely-used index structure for effectively predicting the future positions of moving objects. The TPR*-tree, however, has the problem that both of the in a bounding region and the overlap among bounding regions become larger as the prediction time point in the future gets farther. This makes more nodes within the TPR*-tree accessed in query processing time, which incurs serious performance degradation. In this paper, we examine the performance problem quantitatively via a series of experiments. First, we show how much the performance deteriorates as a prediction time point gets farther from the present, and also show how the frequent updates of positions of moving objects alleviate this problem. Our contribution would help provide important clues to devise strategies improving the performance of TPR*-trees further.

Location-based service is one of the most popular buzzwords in the field of U-city. Positioning a user is an essential ingredient of a location-based system on a U-city. For the outdoor positioning, GPS based practical solutions have been introduced. However, GPS measurement error is too big to be used for U-campus services because the size of a campus is relatively smaller than a city. We propose Relative-Interpolation Method in order to improve the correctness of outdoor positioning. Besides, indoor positioning is necessary for U-campus while GPS signal is not available inside buildings. For the indoor positioning, Cricket, Active Badge, and so on have been introduced. These methods require special equipments dedicated for positioning. Our method does not require such equipments because it determines the user’s position based on the receiver signal strength indicators (RSSI) from access points (AP) which are already installed for WLAN. The algorithm we are using for indoor positioning is a kind of finger prints method. However our algorithm builds a instead of a look-up table in the phase. Therefore, our method is faster than existing indoor positioning methods in the phase. We have integrated our indoor and outdoor positioning methods and implemented a prototype of our indoor-outdoor positioning method on a laptop. Our experimental results are discussed in this paper.

From both technical and economic viewpoints, DiffServ IP QoS architecture is accepted as a more practical solution in Internet world because the other IntServ architecture is more complex and has scalability problem. This paper presents a dynamic DiffServ Model called Indirect DiffServ to support dynamic QoS requirements of SIP-based ASP multimedia applications in broadband access networks. An operational model of QoS-enabled broadband access networks to support dynamic QoS for SIP is firstly proposed. Then the procedures to establish QoS-enabled SIP sessions of ASP applications are presented. The signaling interfaces for dynamic provisioning of DiffServ QoS are designed to be based on COPS and COPS-PR protocols. The inter-layer mapping of QoS attributes between SIP and underlying layers is also discussed in this paper. The underling broadband access networks are assumed to support largely-deployed Metro Ethernet 802.1 D/Q QoS.

Various advanced schemes have been proposed for the establishment of u-city. Especially, most of the schemes are based on ubiquitous networks. In this paper, it is assumed that the ubiquitous networks include some mobile agents. Therefore, an intelligent positioning scheme is presented for the efficient positioning of the mobile agents in the ubiquitous networks. The approach consists of location detection and location tracking. Simulation results indicate that using the algorithm, the excellent detection and tracking performance can be achieved in ubiquitous networks for u-city.

The web user interface offers many advantages; however, a fixed IP address is required to manage each server, it does not have a push function for completion or error messages, it suffers from problems associated with firewalls, and it is slow. To address these issues, we propose an efficient method for controlling information appliances in smart homes that uses a natural language processing technique and an instant messaging system (IMS). The proposed agent-based management system for smart homes provides a user-friendly interface, and can make use of add-on functionalities of the IMS such as voice chatting, SMS, and multimedia. Moreover, the proposed method can be applied using middleware technologies such as Jini [1] UPnP [2], OSGi [4], and HAVi [5].

Web services are based on a web-based system in which the performance of this system becomes a major factor in determining the quality of services.An improvement in the system performance can be achieved using a typeof load uniformity (hereinafter called load balancing) by producing a cluster system using several server systems from a web service provider’s point of view. In addition, certain frequently used web objects or objects that will be frequently applied during web caching from a web service user’s point of view are to be closely related to a nearby web server in clients. This study investigates a method that improves the acceleration performance in a web-based service. A method that distributes loads applied to a web system itself using a dynamic load balancing method, which uses various types of information between nearby servers, was investigated from a web service provider’s point of view.

Recently, with the rapid growth of digital and Internet technologies, the demand for using the Internet in the home have increased. Also, the development of various Internet-based remote controller for smart homes have been prompted, most of which adopt a web interface between people and machines. In this paper, we proposed new user interface (UI) for smart homes with natural language processing (NLP) agent. The aim in the proposed method is to provide the homeowner with the naturalness of the communication for the end-user. In the proposed method, the home server shows to be able to remotely control and monitor appliances, after analyze the plaintext, by using the natural language. Therefore, using the proposed method, almost all appliances of smart homes can be effectively managed through the integrated UI.

The purpose of this study is to present the prediction analysis of traffic accident and future applications by calculating accident risks based on ITS (Intelligent Transport Systems) data via VDS (Vehicle Detecting System). Many researches have described various traffic accident predictions and reductions. However, until recently, empirical studies considering real traffic environments are still insufficient. Site selections in this study were made from accident related data and collected data from VDS to calculate traffic accident rates. Results from analysis showed occurrence of traffic accident by time and explore possibilities for its application in future traffic accident management.

Based on ubiquitous networks, many schemes have been proposed for realization of u-city. For abundance of u-city services to be available, mobile agents can be utilized in ubiquitous networks. However, highly accurate positioning is required for the efficient use of the mobile agents in ubiquitous networks. In this paper, an intelligent diversity scheme is proposed to enhance the positioning performance. Simulation results indicate that using the suggested diversity scheme, the positioning performance can significantly be improved in mobile agents for u-city.

Radio Frequency Identification (RFID) systems can be applied to various areas. A RFID system is composed of tag, reader and host computer. The reader has an antenna for transferring the energy and sending/receiving of data. Cables are used for communication between reader of RFID system and host computer. If a RFID system is implemented in the existing building or gate, the data communication line should be installed in the wall of building or inside of the wall, and this causes some problems. We suggest a solution to this problem, as ID data from tag is transferred to host computer by wireless communication in the reader. In addition, TCP/IP communication can be used for recognizing ID data in long distance.

In this paper, we show a device that sends ID Data from reader to the receiver over wireless network using CC1020 chip and a device that sends ID data from the receiver to the host computer over internet network using W3100A chip. From this, the paper explains the system transferring ID data to the host computer over wireless and Internet network. There are main circuits for each device and block diagram for programming shown in the picture. The system contains a security agent for security managements and services. In addition, the actual data waveform and experimental device are shown in the picture as well as the result of identification in the host computer.