Daehyuck Park

Scalable mobile internet servers: selecting useful images from the web for mobile services

Mobile devices can be easily connected to network anywhere today. Therefore, there are many studies on a variety of contents for mobile devices. In order to provide mobile contents for personal computers in a ubiquitous environment. In this paper, the author propose a framework for obtaining Internet contents intended for personal computers on mobile devices. In other words, the primary concern of this paper is to select the best images for optimal performance and convert them into images that can be effectively reproduced on mobile devices. In case contents should be suitable to various platform devices for service, the load of the server is increased. For this, the performance of the server is to be optimized through selecting useful images among the many available images and converting them while considering the display pixel rates (DPR) and the image distribution areas

Transcoding pattern generation for adaptation of digital items containing multiple media streams in ubiquitous environment

Digital item adaptation (DIA) is one of main parts in MPEG21. The goal of the DIA is to achieve interoperable transparent access to multimedia contents by shielding users from network and terminal installation, management and implementation issues. In general, a digital item consists of multiple discrete or continuous media and adaptation process is to be applied to one of its multiple media. Therefore in the process of adapting the given digital item, the transcoding order of its media has great impact on the adaptation performance because the adaptation process may stop at the point of satisfying a adaptation QoS(Quality of Services). In order to reduce the transcoding time which result in reducing the initial delay time, we propose a pattern based transcoding model for DIA. Because the performance of the model is dependent on the pattern, we also suggest a EPOB based pattern generation method. Finally a sample pattern was suggested based on the experimental results of the method.

Content aware selecting method for reducing the response time of an adaptive mobile web service

One of the particulars to be considered for effective servicing of wireless Internet to mobile terminal is the information of terminal environment. It is because time cost is required in producing mobile contents to suit environment of the connected terminal. In other words, in order to provide mobile web service by considering terminal characteristics, methods to minimize response time and server capacity in accordance with transcoding time in server are required. In this paper, response time to occur in the course of mobile web contents servicing was analyzed and, as a solution for this, Pre-Service method was introduced. Also, this paper suggests two methods in Pre-Service process for selecting optimize content in Cache. One is Device Profile Aware Selection using mobile device information. The other is Content Aware Selection using component information of requested content. Performance level of each method proposed was compared through experiment and the result of analysis was described.

A method of selecting and transcoding content for mobile web service

A factor to be considered in browsing of an existing web page to a mobile terminal is the difference in hardware environments between average PCs and terminals. It is necessary to service contents effectively in accordance with diverse environmental information of various terminals caused by the rapid development in communication devices. This various terminal information needs much time to generate the content for a server and much capacity to load in the server. Therefore the method to minimize response time and server capacity is required. This paper proposes a CA(Content Aware Selecting) and HCT(Hyperlink Based Content Transcoding) method to provide a more rapid response time according to requirements of various terminals and illustrates the results of test system.

An automatic mobile web generation method from PC web using DFS and W-DFS

This thesis intends to suggest how to produce adaptable contents that can be replayed on a device by extracting web contents in order that an existing web page can be replayed by using a device that can replay multimedia technology such as mobile and TV. To perform a service by using MobileGate system and adaptively converting one HTML page existing on web to a device, a page defined as DIDL in MPEG-21 is used. To use numerous amount of web contents in a device having a limited interface, by extracting a contents through DFS method, Circular Doubly-Linked List is established and served. DIDL of average 18 pages to minimize scroll in one web page is generated and all contents on web can be approached and replayed by only up and down button. In this research, web contents service that can be offered by using PC can be offered from mobile and TV device that are under ubiquitous environment.

An Adaptive PC to Mobile Web Contents Transcoding System Based on MPEG-21 Multimedia Framework

The purpose of this paper is to supply web contents for PC to various multi platform device as PDA or portable device. The conventional studies could not consider these devices, so it created mobile contents beforehand, and then transmitted to the limited mobile device. In this point, the critical problem is to generate mobile contents which are suitable for all kinds of mobile device from PC Web content. This paper propose a service system for transmitting wire web content to various portable device by using MPEG-21 Multimedia Framework. It does not create mobile contents for each device. It just uses DIDL of MEPG-21 as intermediate language to express the structure, resource and description of mobile contents. In DIDL, the multimedia resource is transcoded in off-line previously. The description part is converted in real time as soon as service is requested by end-user. Mobile contents integrate adapted resource with appropriate description and then are transmitted. In addition, this paper proposes the Multi-level caching for reusing mobile contents and describes the result in experiment system.

Selecting Useful Images from the Web for Mobile Services

Mobile devices can be easily connected to network anywhere today. Therefore, there are many studies on a variety of contents for mobile devices. In order to provide mobile contents for personal computers in a ubiquitous environment. In this paper, the author propose a framework for obtaining Internet contents intended for personal computers on mobile devices. In other words, the primary concern of this paper is to select the best images for optimal performance and convert them into images that can be effectively reproduced on mobile devices. In case contents should be suitable to various platform devices for service, the load of the server is increased. For this, the performance of the server is to be optimized through selecting useful images among the many available images and converting them while considering the display pixel rates (DPR) and the image distribution areas

A design and implementation of transcoder for displaying diagram data of multimedia title on web browser

This thesis intends to suggest a way to convert it to VML code to play back diagram in internet browser to generate diagram contents used in production of multimedia title as Internet contents, and play it back. By converting multimedia title including excellent contents to web contents, web contents of high quality is intended to be generated. For this, it is rearranged to maintain spatial synchronization of object used inside title in web page by using the CSS Layer and generating VML code, location of playback of diagram contents and shape of the diagram are played back on web page through generation VML code. Through this research, diagram representation that is a difficult problem in converting multimedia title to web contents becomes possible. And furthermore, by using writing tool, diagram of web page can become designed by operating mouse without complex VML code.

Multimedia Content Transcoding for Displaying Space Synchronization on Web Browser

This paper suggests how to convert existing multimedia learning titles into independent multimedia learning Title platform by using XML DB. It stores resource information that takes care of large amount of interactive multimedia learning resources. In existing multimedia learning titles, that resource information is divided and stored at multiple locations, but it store and manage the information in a database. Also Internet browsers are used to play those titles regardless of which platform those are played, so there are no needs for dedicated Multimedia Learning players. As a result of this research, multimedia learning titles can be played in various environments, like local terminal and server, without computer specification limitations.

The Pre-Service and Post-Transcoding Method for Enhancing the Response Time of Mobile Web Service

ABSTRACT One of the particulars to be considered for providing wireless web service with PC web page is the hardware environment between PC and mobile device. It is because time cost is required in producing mobile contents to suit environment of the connected terminal. Therefore, server side should take account of response time and disk capacity of server. Response time is delayed by content conversion and disk capacity need to store various versions about one content. This paper suggests a pre-service and post-transcoding method to provide faster response time for a mobile terminal. The pre-service is to minimize response time by placing the top priority in servicing contents saved in cache as much as possible even if the quality of contents serviced to mobile terminal may be low. After pre-service is provided, the mobile content is transcoded for the terminal later. Performance level of method proposed was compared through experiment and the result of analysis was described.Key Words:Mobile Web Service, Pre-Service, Post-Transcoding, Cache, Mobile Gate