• Journal of Computing Science and Engineering
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• v.2 no.4
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• pp.321-338
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• 2008

This paper presents a Modified Multiple Depth First Search algorithm for the exploration of the indoor environments occupied with obstacles in random distribution. The proposed algorithm was designed and implemented to employ one or a team of Khepera II mini robots for the exploration process. In case of multi-robots, the BlueCore2 External Bluetooth module was used to establish wireless networks with one master robot and one up to three slaves. Messages are sent and received via the module's Universal Asynchronous Receiver/Transmitter (UART) interface. Real exploration experiments were performed using locally developed teleworkbench with various autonomy features. In addition, computer simulation tool was also developed to simulate the exploration experiments with one master robot and one up to ten slaves. Computer simulations were in good agreement with the real experiments for the considered cases of one to one up to three networks. Results of the MMDFS for single robot exhibited 46% reduction in the needed number of steps for exploring environments with obstacles in comparison with other algorithms, namely the Ants algorithm and the original MDFS algorithm. This reduction reaches 71% whenever exploring open areas. Finally, results performed using multi-robots exhibited more reduction in the needed number of exploration steps.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.367-369
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• 2022

With the development of web technology, the web provides customized information that meets the needs of users. Information is provided according to the input form and the user's query, and a web service that provides information that is difficult to search with a search engine is called an in-depth web. These deep webs contain more information than surface webs, but it is difficult to collect information with general crawling, which collects information at the time of the visit. The deep web provides users with information on the server by running script languages such as javascript in their browsers. In this paper, we propose an algorithm capable of exploring dynamically changing websites and collecting information by analyzing scripts for deep web collection. In this paper, the script of the bulletin board of the Korea Centers for Disease Control and Prevention was analyzed for experiments.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.10a
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• pp.871-874
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• 2007

Stream data need a efficient data management with high reliability and real time processing. The characteristics of these data are a large volume, a short report interval and asynchronous report time. The typical queries of these systems consist of the current query to search the latest signal value, the snapshot query to search the signal value of a past time, the historical query to search the signal value of a past time to current. This paper proposes the efficient method to manage the above signals by using a file structured database in QNX operating systems. The query model to accommodate various query for stream data is proposed. The proposed methods are applied to reactive protection system to verify their usefulness. The COM(Cabinet Operator Module) based on the QNX employs file database that adopts a delta version and a buffering method for the resource limit of a small storage and a low computing power.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.461-465
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• 2006

Recently, the operator modules to control external devices are concerned about automatic management system to process continuously changed signals. They need a efficient data management with high reliability and real time processing. The characteristics of these data are a large volume, a short report interval and asynchronous report time. The typical queries of these systems consist of the current query to search the latest signal value, the snapshot query to search the signal value of a past time, the historical query to search the signal value of a past tine to current. In this paper, we propose the efficient method to manage the above signals by using a file structured database in QNX operating systems. The data communications among the devices are done by Profibus-FMS protocol and the file databases are used for adjusting monitoring frequency and storing signals. The file database adopts a delta version and a periodical back up in due consideration of the resource limit of a small storage and a low computing power in QNX COM(Cabinet Operator Module).

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.5
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• pp.11-18
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• 2009

Ajax based on Java Script receives attention as an alternative to ActiveX technology. Most portal sites in korea show a tendency to reopen existing services by combining the technology, because it supports most web browsers, and has the advantages of such a brilliant interface, excellent speed, and traffic reduction through asynchronous interaction. This paper modeled and implemented a multilingual meta-search service using the Ajax and open APIs provided by international famous sites. First, a Korean query is translated into one of the language of 54 countries around the world by Google translation API, and then the translated result is used to search the information of the social web sites such as Flickr, Youtube, Daum, and Naver. Searched results are displayed fast by dynamic loading of portion of the screen using Ajax. Our system can reduce server traffic and per-packet communications charges by preventing redundant transmission of unnecessary information.

• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.6
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• pp.651-656
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• 2010

In the homepage of 16 municipal provincial office of education, school information service displays text-based results through search step or presents the simple information of the selected area when an area is clicked on the static image map. And it has several problems such as server load and slow transfer speed by the search of the synchronous transfer. Thus, in this study, we used the open API of Google map to provide location-based school information and implemented the mash up service for school information with the Ajax program of asynchronous transfer to reduce server load and to increase transmission speed. This service gives the efficiency and convenience to students, teachers, parents and education family members of various levels because it includes the location with school information on a dynamic map.

• Journal of Korea Society of Industrial Information Systems
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• v.4 no.4
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• pp.60-70
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• 1999

Internet based on web service is growing rapidly and the effort to standardize the next generation web is wold-widely being made. When the web was developed for the first time, HTTP, HTML, and URL were designed based on the structure of text background. Through those asynchronous search and simple unified expression patterns have been used But recently many data on internet me becoming complicated Consequently new structure and expression patterns including synchronous multimedia information are requested The currently used standard language among user interface domain of W3C is SMIL which is XML-based one SMIL describes where and how long the multimedia factors are integrated on the web. In this paper the standardization trend and important issues related to SMIL are reviewed and analysed Also the development of technology is discussed.

• Journal of Korea Society of Industrial Information Systems
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• v.6 no.3
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• pp.1-19
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• 2001

Internet based on web service is growing rapidly and the effort to standardize the next generation web is world-widely being made. When the web was developed for the first time, HTTP, HTML, and URL were designed based on the structure of text background. Through those, asynchronous search and simple, unified expression patterns have been used. But recently many data on internet are becoming complicated. Consequently new structure and expression patterns including synchronous multimedia information are requested. The currently used standard language among user interface domain of W3C is SMIL which is XML-based one. SMIL describes where and how long the multimedia factors are integrated on the web. In this paper the standardization trend and important issues related to SMIL are reviewed and analyzed. Also the development of technology is discussed.

• Journal of Korea Multimedia Society
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• v.7 no.11
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• pp.1556-1563
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• 2004

In this paper, we propose an efficient full mesh topology aggregation method in PNNI networks. The proposed scheme can search multi-links efficiently using the depth priority method based on hop count instead of searching the all links. To do this, we propose a modified line segment algorithm using two line segment method that represents two points which consist of delay-bandwidth pair to reduce topology information and provide a flexibility to the multiple-links aggregation. And we apply it to current full mesh topology aggregation. To evaluate performance of the proposed scheme, we compare/analyze the current method with the proposed scheme with respect to call success rate, access time and crank back rate. The result is that the proposed scheme is better than the current scheme in performance.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2012.07a
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• pp.215-218
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• 2012

반도체 기술 및 방송통신기술의 발달에 따라 소비자는 복잡하고 다양한 서비스 환경을 접하고 있으며, 개인당 소비되는 콘텐츠의 양은 기하급수적으로 증가 되고 있다. 스마트폰과 같은 멀티미디어기기의 발전으로 기존의 단순 시청에서 벗어나 멀티미디어 검색과 추천과 같은 다양한 서비스들이 제공되고 있으며, 웹과 인터넷을 기반으로 하는 정보기술은 모바일 전자 기술의 발달에 따라 데스크톱이라는 공간적인 한계를 벗어나 유기적인 유비쿼터스 환경으로 변화하고 있다. 이와 같이 소비자들이 접하는 멀티미디어의 양이 증가됨에 따라, 멀티미디어를 검색하기 위한 다양 서비스들이 사업자들을 통해 제공되고 있다. 그러나 사업자들이 구축한 서버들은 공유되어지지 못하며, 공유되더라도 공유하기 위한 방법이 제각각이다. 이에 MPEG에서는 멀티미디어 콘텐츠를 검색하기 위한 질의 구조를 표준화 하여, 서비스 제공자 및 소비자들에게 유용한 검색 인터페이스를 제공하였다. 이에 본 논문에서는 MPEG Query Format에 기반 하여 임베디드 환경에서 광대한 양의 음악 콘텐츠에서 사용자가 원하는 허밍 질의를 편리하게 검색하기 위한 방법을 성계 및 구현한다.