Showing papers by "Shojiro Nishio published in 2006"

A collaborative Web browsing system for multiple mobile users

Abstract: In mobile computing environments, handheld devices with low functionality restrict the services provided for mobile users. We propose a new concept of collaborative browsing, where mobile users collaboratively browse Web pages designed for desktop PC. In collaborative browsing, a Web page is divided into multiple components, and each is distributed to a different device. In mobile computing environments, the number of handheld devices, their capabilities, and other conditions can vary widely amongst mobile users who want to browse content. Therefore, we developed a page partitioning method for collaborative browsing, which divides a Web page into multiple components. Moreover, we designed and implemented a collaborative Web browsing system in which users can search and browse their target information by discussing and watching partial pages displayed on multiple devices.

Image classification for mobile web browsing

Abstract: It is difficult for users of mobile devices such as cellular phones equipped with a small screen and a poor input interface to browse Web pages designed for desktop PCs with large displays. Many studies and commercial products have tried to solve this problem. Web pages include images that have various roles such as site menus, line headers for itemization, and page titles. However, most studies of mobile Web browsing haven't paid much attention to the roles of Web images. In this paper, we define eleven Web image categories according to their roles and use these categories for proper Web image handling. We manually categorized 3,901 Web images collected from forty Web sites and extracted image features of each category according to the classification. By making use of the extracted features, we devised an automatic Web image classification method. Furthermore, we evaluated the automatic classification of real Web pages and achieved up to 83.1% classification accuracy. We also implemented an automatic Web page scrolling system as an application of our automatic image classification method.

Design of a Car Navigation System that Predicts User Destination

Abstract: Because of advances in information technologies, car navigation systems have come into widespread use as useful tools to guide drivers where they want to go. Conventional car navigation systems present the most suitable route according to a destination input into the system. However, since the required operation to input the destination costs so much, users do not usually use car navigation systems for daily driving. In this paper, to exploit the effective functions of car navigation systems, we propose a new system that automatically predicts user purpose and destination. The proposed car navigation system presents various information based on predicted purpose without interaction from users.

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

Abstract: 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.

Replica allocation considering power consumption in mobile ad hoc networks

Abstract: In ad hoc networks, it is effective that each mobile host creates replicas of data items held by other hosts for improving data accessibility. However, a mobile host holding data items frequently accessed by other hosts needs to transmit them many times and consumes more power than other hosts. In this paper, we propose a replica allocation method for not only improving data accessibility but also balancing the power consumption among mobile hosts. In this method, each mobile host replicates data items considering their access frequencies, the numbers of their replicas, and the remaining amount of its battery. We present simulation results to evaluate the performance of our proposed method.

Design and Implementation of a Real-Time Fingering Detection System for Piano Performance

Abstract: Fingering is an important aspect of piano performance because it affects a pianist’s musicality. If audience members, especially pianists, shared the real-time fingering of the performer in a concert, they would feel a sense of togetherness, and this could help them in learning techniques of professional piano performance. To realize such a possibility, the goal of our study is to construct a real-time fingering detection system for piano performance. Our system achieves real-time fingering detection by integrating a simple camerabased image-detection method and musical rules. We have developed a prototype system and evaluated in effectiveness by actual use.

On updated data dissemination exploiting an epidemic model in ad hoc networks

Abstract: In ad hoc networks, it is effective that each mobile host creates replicas of data items held by other mobile hosts for improving data accessibility In our previous work, we assumed an environment where data items are updated and proposed two updated data dissemination methods which efficiently update old replicas In these methods, the communication traffic is large since every mobile host necessarily requests updated data items when it knows that its own replicas are old In this paper, we propose an updated data dissemination method exploiting an epidemic model, which is a popular bio-inspired approach, for reducing the communication traffic In our proposed method, mobile hosts disseminate invalidation reports and discard old replicas when a mobile host updates a data item or when two mobile hosts are connected with each other Each mobile host which discards an old replica requests the updated data item with a certain probability We also present simulation results to evaluate the performance of our proposed method

Profile-based Query Routing in a Mobile Social Network

Abstract: Recently, there has been an increasing interest in a social network. In a social network, nodes and links represent participants and their friendships, respectively. We have designed and implemented a query propagation mechanism and its applications to realize a social network composed by cellular phone users. In these applications, users can retrieve information from their friends or their friends’ friends by propagating the query in the network. To propagate a query in a wide range and improve the query success ratio, most users who receive the query must relay it to all their friends. However, this increases communication packets. In this paper, we propose a query routing method to decrease the number of communication packets by using user profiles.

A data access method considering power consumption in ad hoc networks

Abstract: In ad hoc networks, it is effective that each mobile host creates replicas of data items held by other mobile hosts for improving data accessibility. When a mobile host requests a data item (replica) held by another mobile host, it usually uses the shortest path for the data transmission. In this case, mobile hosts at the center of the network relay many data items and consume much power. In this paper, we propose a data access method to balance the power consumption among mobile hosts. This method selects a path between the request issuing host and the requested data holder considering the path length and the remaining amount of batteries of mobile hosts along the path. We present simulation results to evaluate the performance of our proposed method.

Consistency Management among Replicas Using a Quorum System in Ad Hoc Networks

Abstract: Data replication is effective for improving data availability in ad hoc networks. In an environment where data updates occur, replicas of a data item may be inconsistent. To solve this problem, quorum based consistency management is a promising approach. To reduce communication overhead, it is better to make the number of mobile hosts in each quorum small. In this paper, we propose a consistency management method that constructs quorums with fewer mobile hosts.

On a Cooperation of Broadcast Scheduling and Base Station Caching in the Hybrid Wireless Broadcast Environment

Abstract: In this paper, based on the Hybrid Wireless Broadcast (HWB) model, we investigate a cooperative data management strategy to provide more efficient data delivery to the mobile clients. This strategy integrates broadcast scheduling with cache management of the base station by making effective use of the HWB data dissemination, namely push- and pull- based broadcast and pull-based point-topoint wireless communication. Simulation study demonstrates that the proposed cooperation strategy can improve the system performance.

Two Approaches to Browse Large Web Pages Using Mobile Devices

Abstract: In this paper, we introduce two our approaches to browse large Web pages designed for desktop PCs using mobile devices with small screens and poor input interfaces. In the first approach, multiple mobile users collaboratively browse large Web pages. We call this approach collaborative browsing. In the second approach, automatic scrolling in a large Web page is performed, where contents in the page are traversed. This enables users to rapidly view the page with the users’ minimum operations.

Two Approaches to Browse LargeWeb Pages Using Mobile Devices

Abstract: In this paper, we introduce two our approaches to browse large Web pages designed for desktop PCs using mobile devices with small screens and poor input interfaces. In the first approach, multiple mobile users collaboratively browse large Web pages. We call this approach collaborative browsing. In the second approach, automatic scrolling in a large Web page is performed, where contents in the page are traversed. This enables users to rapidly view the page with the users’ minimum operations.

A web browsing system based on adaptive presentation of web contents for cellular phones

Abstract: Cellular phones have already been widely used to access the Web. However, most existing Web pages are designed for desktop PCs, and thus, it is inconvenient to browse these large Web pages on a cellular phone with a small screen and poor interfaces. Users who browse a Web page on a cellular phone have to scroll the whole page to find an objective content, and then, have to scroll within the content in detail to get useful information. In this paper, we propose a novel browsing system to break off these burdensome operations by adaptively presenting Web contents according to their characteristics.

Update Log Dissemination in Mobile Ad Hoc Networks

Abstract: In mobile ad hoc networks where data items are updated, each mobile host cannot verify whether its own replica is the same version as the original when it does not connect to the mobile host holding the original (original holder). In this paper, we propose two update log dissemination methods that efficiently verify the validity of tentative accesses to replicas. In the first method, the original holder efficiently disseminates the update logs to other hosts. In the other method, mobile hosts which are not the original holder also manage the update logs and two newly connected mobile hosts re-disseminate the logs. We also present simulation results to evaluate the performance of our methods.

A Position DetectionMechanism for Location-aware Pin&Play

Abstract: We propose a position detection mechanism for locationaware Pin&Play. Though the positions of inserted pins are important for most applications, they could not be detected in previous systems. The proposed method detects the positions of pins by processing images taken with a camera placed in front of the board. The proposed method has a dynamic adjustment mechanism for image processing parameters to achieve higher accuracy even when the surrounding lighting condition changes. Moreover, it also has an error estimation mechanism to avoid the accumulation of position error. We also clarify the effectiveness of our proposed method through performance evaluations.

GeoNote.net: A Social Network System for Geographic Information

Abstract: GeoNote.net is a social network system which allows users to share geographic information among their friends network. The system has various notable features and uses several key technologies such as social network construction methods, security for personal information, geographic information management on mobile devices including cellular phones, retrieval of geographic information according to the friends network, and so on. In this paper, we describe the system under design aspects and implementation aspects.

A Query Processing Mechanism Based on the Broadcast Queue for Broadcast Database Systems

Abstract: In recent years, there has been an increasing interest in the broadcast database system, where the server periodically broadcasts contents of a database to mobile clients such as PDAs. There are three query processing methods in the broadcast database system: (i) the server processes a query and then broadcasts the query result to the client; (ii) the client stores all data that are necessary in processing the query and then processes it locally; and (iii) the server and the client collaborate in processing the query. Since the performance of each method changes according to the situation, such as the interval of query generation and the size of query results, it is difficult to decide the optimal method among them statically. In this paper, we propose a new query processing method which dynamically changes the order of queries submitted in the queue at the server and also changes processing methods for the queries according to the deadline of queries and the system situation. Our method not only improves the response time but also increases the success rate of query processing compared with the traditional methods.

Probabilistic replication based on access frequencies in unstructured peer-to-peer networks

Abstract: Recently, there has been increasing interest in research on data sharing through peer-to-peer networks. In this paper, assuming a data-sharing service, we propose a new replication strategy that achieves not only load balancing but also improvement of search performance. The proposed strategy creates replicas at each peer on the path along which a query is successfully forwarded, depending on the peer's rank of access frequency to the data. Moreover, we verify the effectiveness of the proposed strategy by simulation experiments.

Probabilistic replication based on access frequencies in unstructured peer-to-peer networks

Abstract: Recently, there has been increasing interest in research on data sharing through peer-to-peer networks. In this paper, assuming a data-sharing service, we propose a new replication strategy that achieves not only load balancing but also improvement of search performance. The proposed strategy creates replicas at each peer on the path along which a query is successfully forwarded, depending on the peer's rank of access frequency to the data. Moreover, we verify the effectiveness of the proposed strategy by simulation experiments.

Nine-Button Web Browsing System for Cellular Phone Users

Abstract: Cellular phones are widely used to access the Web. However, most available Web pages are designed for desktop PCs, and it is inconvenient to browse these large Web pages on a cellular phone with a small screen and poor interfaces. Users who carry cellular phones browse Web pages in various situations. Therefore, appropriate browsing styles are different based on their situations. In this paper, we propose a novel Web browsing system called nine-button browsing system, in which numerical keys of cellular phone have different functions for presenting Web pages. This system enables users to browse Web pages comfortably adapting their situations.

Ubiquitous Gadgets for Constructing Flexible Ubiquitous Services

Abstract: In the near future, small ubiquitous devices will be embedded into most of artifacts to support human dailylife. In such environments, we need multiple types of human-computer interfaces for enjoying ubiquitous services. This paper describes several ubiquitous gadgets; ubiquitous chip, Pin&Play, and VCC, to provide flexible ubiquitous services and user interfaces. The integrative use of these devices achieves the physical and intuitive interaction between users and ubiquitous services.

A Query Processing Method Considering Query Frequency for Broadcast Database Systems

Abstract: In recent years, there has been an increasing interest in broadcast database systems, where the server periodically broadcasts contents of a database to mobile clients such as PDAs. There are three query processing methods in the broadcast database system: (i) the server processes a query and then broadcasts the query result to the client; (ii) the client stores all data that are necessary in processing the query and then processes it locally; and (iii) the server and the client collaborate in processing the query. Since the performance of each method changes according to the system situation, such as query frequency, it is difficult to decide the optimal method among them statically. In this paper, we propose a new query processing method which dynamically changes the query processing method based on query frequency. This method improves not only the response time but also the success rate of query processing compared with the traditional methods.

TEMPEST: a text input system for musical performers

Abstract: Recently, due to the widespread use of computers, text-based communication methods, such as e-mail and chat, have attracted a great deal of attention. If pianists can apply their musical expressions to the text input, they can input texts with their own emotion richly. Therefore, the goal of our study is to construct TEMPEST (TExt input and Musical PErforming SysTem) that is a text input system to input texts with various musical expressions using a clavier. Since this system provides text input methods considering musical artistry, a performer can input texts like playing music.

Discovering Important Rules and Loyal Customer by Considering the Repetition in Association Rules

Abstract: In this paper, we present a study on association rule mining based on real POS data from a SME (small and medium enterprise). Our main contribution is proposing a new criterion, called R-repeat, to evaluate the significance of rules by focusing attention to the purchase pattern repeated by a certain customer. We also focus on detecting a special customer segment, called R-repeater. In addition, we make a comparison between R-repeater segment and the customer segments by REM analysis, and confirm that R-repeater is a loyal customer segment

TEMPEST : A text input system for musical performers

Abstract: Recently, due to the widespread use of computers, text-based communication methods, such as e-mail and chat, have attracted a great deal of attention. If pianists can apply their musical expressions to the text input, they can input texts with their own emotion richly. Therefore, the goal of our study is to construct TEMPEST (TExt input and Musical PErforming SysTem) that is a text input system to input texts with various musical expressions using a clavier. Since this system provides text input methods considering musical artistry, a performer can input texts like playing music.

A Hybrid Data Delivery Method of Data Broadcasting and On-demand Wireless Communication

Abstract: As the recent advances in the wireless technologies and mobile terminals, mobile users equipped with mobile devices are able to access wireless services through 3G cellular network, WiFi hotspot, or WiMAX link, as well as through satellite digital broadcast or terrestrial digital broadcast. By effectively taking advantage of these complementary communication modes, we explore a new hybrid data delivery model, i.e., Hybrid Wireless Broadcast (HWB) model to benefit from the optimal combination of the push-based and pull-based broadcast and on-demand point-to-point wireless communication. The HWB model can provide a flexible and complementary information service in different bandwidths and service ranges, and greatly improve the responsibility, scalability, and efficiency of the system. The results of simulation study show the proposed HWB approach achieves a significant improvement in system performance.

An information browsing system using a Java-based cellular phone in a remote display environment

Abstract: In this paper, we design and implement an information browsing system by using a Java-based cellular phone in the remote display environment that we have proposed. In this system, an application on a remote display displays various information for users, and a Java application on a cellular phone displays operational pages for users to operate the application on the remote display. Users can browse information on the remote display by operating the corresponding operational pages on the cellular phone. Both applications run according to their schedules that specify the behaviors and their execution times. In addition, the Java application personalizes operational pages based on the user's personal information. © 2006 Wiley Periodicals, Inc. Syst Comp Jpn, 37(10): 1–12, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/scj.20562