Tomoki Yoshihisa

A Broadcasting Scheme for Selective Contents Considering Available Bandwidth

Due to the recent popularization of digital broadcasting systems, selective contents, i.e., watching contents selected by users themselves, have attracted great attention. For example, in a news program, after a user selects an interesting content, he/she watches it. In selective contents broadcasting, since the server needs to deliver many contents, the necessary bandwidth for continuously playing the data increases. Conventional schemes reduce the necessary bandwidth by producing an effective broadcast schedule. However, they do not consider the upper limit in the bandwidth. When an upper limit exists in the bandwidth, users may wait to play the data. In this paper, we propose a broadcasting scheme that reduces waiting time by considering available bandwidth. In our proposed scheme, by acquiring the channel bandwidth that is the same as the data consumption rate, we effectively reduce the waiting time.

Ubiquitous Chip: A Rule-Based I/O Control Device for Ubiquitous Computing

In this paper, we propose a new framework for ubiquitous computing by rule-based, event-driven I/O (input/output) control devices. Our approach is flexible and autonomous because it employs a behavior-description language based on ECA (Event, Condition, Action) rules with simple I/O control functions. We have implemented a prototype ubiquitous device with connectors and several sensors to show the effectiveness of our approach.

A scheduling scheme for continuous media data broadcasting with a single channel

Recently, various schemes for broadcasting continuous media data such as audio and video have been studied. Some of them have focused on reducing the waiting time of clients under the condition that clients can play data without interruption from beginning to end. These schemes usually employ multiple channels to broadcast continuous media data. However, clients for most broadcast systems such as wireless LAN, DVB and ISDB-T cannot receive data from multiple channels concurrently. In this paper, we propose and evaluate a scheduling scheme to reduce the waiting time of clients with a single channel. Preliminary results suggest that this scheme outperforms existing schemes.

A Data Reception Method to Reduce Interruption Time in P2P Streaming Environments

In recent years, there has been an increasing interest in P2P (Peer-to-Peer) streaming environments. In P2P streaming environments, compared with the traditional server-client model, the load of the server can be reduced by transmitting the divided streaming data (pieces) among clients. However, when bandwidths between clients are narrow, interruption occurs since clients cannot receive the necessary piece of data until the time to play it. In this paper, we propose a data reception method to reduce interruption time in P2P streaming environments. Our proposed method calculates the importance of each piece which takes into account the immediacy and the scarcity of the piece. The evaluation results show that our proposed method can reduce the interruption time for peers in a P2P environment compared with conventional methods.

A Scheduling Method Considering Available Bandwidth in Selective Contents Broadcasting

Due to the recent popularization of digital broadcasting systems, selective contents, i.e., watching contents users selected themselves, have attracted great attention. For example, in a news program, after a user selects the desired content, he/she watches it. In selective contents broadcasting, since the server needs to deliver many contents, the necessary bandwidth for playing the data without interruptions increases. Although conventional methods reduce necessary bandwidth, they do not consider the upper limit in the bandwidth. When upper limit exists in the bandwidth, users have to wait to receive the data. In this paper, we propose a scheduling method to reduce waiting time by considering available bandwidth. In our proposed method, by acquiring the bandwidth that is the same as the data consumption rate, waiting time is effectively reduced.

A Broadcasting Scheme Considering Units to Play Continuous Media Data

Due to the recent proliferation of digital broadcasting systems, various schemes for broadcasting continuous media data such as music or movies have been studied. In general broadcasting systems, since clients have to wait until their desired data are broadcast, these schemes reduce the waiting time by dividing the data into several segments of equal size. However, continuous media data often have units for playing portions of the data. For example, data encoded by MPEG2 can be played every GOP (group of pictures). In this paper, we propose a scheme to reduce the waiting time considering the units. Our proposed scheme divides a continuous media data at every unit. By scheduling divided data so that clients finish receiving a unit before starting to play the unit, waiting time is effectively reduced.

Foot-Step Input Method for Operating Information Devices While Jogging

We propose an input interface using Foot-Step which is gestures of foot for information appliances while jogging. When we use information appliances while jogging, an input by Foot-Step is briefer way than conventional physical interfaces because of the hands-free capability.We developed a prototype of a Foot-Step system which enables a user to operate a menu selection system which is widely used for information appliances. The system equips 3-axes acceleration sensors on shoes and users operate a menu system by Foot-Step. As Foot-Step makes the operation of a menu system a part of jogging, we expect selecting menu motivates users to keep running and users enjoy jogging more.

A Scheduling Protocol for Continuous Media Data Broadcasting With Large-Scale Data Segmentation

Due to the recent popularization of mobile multimedia broadcasting, broadcasting continuous media data such as audio and video has attracted great deal of attention. In general continuous media data broadcasting, since clients have to wait to receive data before playing it, various schemes to reduce waiting time have been studied. Some reduce the waiting time by dividing the data into several segments and broadcasting preceding segments frequently with a single channel. However, by dividing the data into numerous segments and producing an effective broadcast schedule, the waiting time can be further reduced. In this paper, we propose a scheduling protocol to reduce waiting time with large-scale data segmentation.

A Division-Based Broadcasting Method Considering Channel Bandwidths for NVoD Services

Due to the recent proliferation of digital broadcasting, several methods for broadcast streaming data, i.e., movies or music, using the division-based broadcasting scheme have been studied. In the division-based broadcasting scheme, by dividing the data into several segments and broadcasting them via multiple channels, the waiting time for clients to start playing the data is reduced. These methods usually calculate appropriate channel bandwidths and allocate them to each channel. However, in many cases, channel bandwidths are fixed for the restrictions of the broadcasting system. Therefore, it is difficult to allocate arbitrary bandwidths to each channel. In this paper, we propose a division-based broadcasting method considering channel bandwidths. Our proposed method divides the data into several segments based on the given channel bandwidths. By dividing the data so that clients can receive the next segment immediately before finishing playing each segment, the waiting time is reduced satisfying the condition that clients can play the data without any interruptions.

A rule-based RFID tag system using ubiquitous chips

Because of the recent development of radio frequency identification (RFID) technologies, various systems for RFID tags have been proposed. Since RFID tags only have a simple function, i.e., sending data, they can be available for various purposes. Accordingly, by customizing RFID tag systems, we can expand their applications. However, previous systems have been usually proposed for one special purpose only. In this paper, we propose a rule-based RFID tag system using ubiquitous chips. Our previously proposed ubiquitous chips are rule-based I/O control devices. By applying rule-based principles, we can easily customize the RFID tag system and can construct flexible, scalable, and easy exploitable systems.