• Proceedings of the Korean Information Science Society Conference
• /
• 2011.06d
• /
• pp.149-152
• /
• 2011

본 논문에서는 무선 메쉬 네트워크에서 H.264 비디오 코딩을 이용한 대화형 멀티미디어 전송시 서비스 품질을 향상시키기 위한 Early Drop 기법을 제안한다. Early Drop 기법은 비디오 프레임의 재생시간과 H.264로 부호화된 비디오 프레임의 중요도를 고려하여 네트워크 혼잡 시 발생하는 큐잉 지연과 큐 오버플로우로 인한 비디오 서비스 품질 저하를 효과적으로 개선하기 위해 개발되었다. 계층간 최적화(Cross-Layer)기법을 사용하여 각 비디오 패킷 별로 재생시간까지 남은 시간을 의미하는 delay budget을 할당하고 전송 중 재생시간 초과로 인해 목적지 노드에서 재생되지 못하는 비디오 패킷을 전송 초기 손실 시켜 무선대역폭 낭비와 전송 지연을 최소화 한다. 또한, H.264 비디오 프레임 종류별 중요도를 고려하여 차별화 된 delay budget을 할당해 중요도가 높은 비디오 프레임의 전송을 보장하여 비디오 전송 품질을 높인다. 성능 검증을 통해 네트워크 혼잡 시 Early Drop 기법은 기존에 제안된 IEEE 802.11e 기반의 H.264 비디오 전송기법과 비교하여 전송지연과 프레임 손실률을 최소화해 향상된 비디오 품질을 보였다.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.04a
• /
• pp.603-606
• /
• 2002

최근 WWW의 기하급수적인 성장과 더불어 인터넷 서비스를 통한 정보 획득과 공유 및 원격 시스템 접속을 통한 인터넷 응용 처리 서비스에 대한 연구가 많이 이루어지고 있고, 이는 학습과 교수 업무지원 분야에서도 용용되고 있다. 특히 교수를 위한 복잡한 학교 업무의 관리와 학습자료 및 업무 자료를 지원하기 위해서는 확장성과 호환성, 편의성을 제공하는 XML 형태의 전자문서가 제공되어져야 한다. 따라서 웹을 기반으로 다수의 교수자들이 교수 업무 지원을 위해 XML 문서를 효율적으로 작성하고 공유할 수 있는 적절한 교수 지원 시스템이 필요하게 되었다. 이는 웹 상에서 XML 문서의 효과적인 생성과 검색 및 의도된 문서를 재사용 가능하도록 제공함으로써 교수자의 다양한 요구 사항을 융통성있게 수용할 수 있다. 따라서 본 논문에서는 웹 상에서 XML 문서 제공을 위한 교수 지원 시스템을 구현하였다. 본 시스템을 통해서 교수자들은 XML 문서를 효율적으로 생성, 등록, 수정하고 또한 문서를 대화적으로 검색하고 이해하며, 다양한 형태의 문서를 획득할 수 있다. 따라서 교수 지원시 업무처리의 효율성과 작성된 XML 문서의 재사용성을 증대시킬 수 있다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.719-721
• /
• 2010

VoIP over MANET is an important IP phone technique used in mobile ad-hoc networks. VoIP system over wired networks is based on SIP, SIP UA and SIP server which process the users invite, register and so on. Since no base stations in MANETs to perform as SIP servers, VoIP service on MANETs is being done with tiny SIP server which is done on each node. In this paper, VoIP system is implemented with pseudo SIP server which can process 1 call based on modification of standard SIP server which is used on communication environment such as wired networks. The propesed system is performed well and compatible with SIP and SIP UA.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.6
• /
• pp.125-134
• /
• 2009

A biological data acquisition based on web has emerged as a powerful tool for allowing scientists to interactively view entries form different databases, and to navigate from one database to another molecular-biology database links. In this paper, the biological conceptual model is constructed hybrid biological data model to represent interesting entities in the data sources to applying navigation rule property for each biological data source based on four biological data integrating layers to control biological data. When some user's requests for application service are occurred, we can get the data from database and data source via web service. In this paper, we propose a query processing model and execution structure based on integrating data layers that can search information on biological data sources.

• Annual Conference on Human and Language Technology
• /
• 2023.10a
• /
• pp.525-530
• /
• 2023

최근 소셜 네트워크 서비스(SNS) 및 모바일 서비스가 증가함에 따라 사용자들은 다양한 종류의 위험에 직면하고 있다. 특히 온라인 그루밍과 온라인 루머 같은 위험은 한 개인의 삶을 완전히 망가뜨릴 수 있을 정도로 심각한 문제로 자리 잡았다. 그러나 많은 경우 이러한 위험들을 판단하는 시점은 사건이 일어난 이후이고, 주로 법적인 증거채택을 위한 위험성 판별이 대다수이다. 따라서 본 논문은 이러한 문제를 사전에 예방하는 것에 초점을 맞추었고, 계속적으로 발생하는 대화와 같은 event를 실시간으로 감지하고, 위험을 사전에 탐지할 수 있는 Real-Time Early Risk Detection(RERD) 문제를 정의하고자 한다. 온라인 그루밍과 루머를 실시간 조기 위험 감지(RERD) 문제로 정의하고 해당 데이터셋과 평가지표를 소개한다. 또한 RERD 문제를 정확하고 신속하게 해결할 수 있는 강화학습 기반 새로운 방법론인 RT-ERD 모델을 소개한다. 해당 방법론은 RERD 문제를 이루고 있는 온라인 그루밍, 루머 도메인에 대한 실험에서 각각 기존의 모델들을 뛰어넘는 state-of-the-art의 성능을 달성하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.05a
• /
• pp.327-330
• /
• 2012

In the rapid growth of cities, road has heavy traffic and many buildings are under constructions. These kinds of environments make more difficulty for a person who is visually handicapped to walk comfortable. To alleviate the problem, we introduce Android based Portable Navigation System to help walking for Visually Impaired Person. It follows, service center give instant real time monitoring to visually impaired person for their convenient by this system. Android based Portable Navigation System has GPS, Camera, Audio and WI-FI(wireless fidelity) available. It means that GPS location and Camera image information can be sent to service center by WI-FI network. To be specific, transmitted GPS location information enables service center to figure out the visually impaired person's whereabouts and mark the location on the map. By delivered Camera image information, service center monitors the visually impaired person's view. Also, they can offer live guidance to visually impaired person by equipped Audio with live talking. To sum up, Android based Portable Navigation System is a specialized navigation system that gives practical effect to realize more comfortable walking for visually impaired person.

• Journal of the Korean Society for information Management
• /
• v.35 no.3
• /
• pp.215-244
• /
• 2018

The role of archives and records centers is expanding, however many potential users are not aware of the importance of the records and archives. As a method to improve the archival information services to users, in this study, we developed chatbot that supports the interaction between the users and the archives and records centers. Thus we examined the specific development procedures and methods, analyzed user requests and questions of the archives and records center of Myongji university as a case, and conducted a logical structure design for chatbot development. After building the chatbot based on IBM Watson Conversation and Kakaotalk messenger, we were able to find how the chatbot interacted with the users through a pilot run. Based on the experience of developing information service chatbot, the implications related the introduction of the chatbot were suggested which include determination of the level of the chatbot, analysis of the user requests, selection of the tool for the chatbot, and syntax setting for the conversational interaction.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.8C
• /
• pp.690-696
• /
• 2012

Recently, the need for telemedicine services and user's service requirements are increasing, the research for more convenient telemed service is underway in various fields. In this paper, we propose that Integrated telemedicine system possible to regular health care. unlike the existing telemedicine system, we combine the voice communications systems and biometric information based on CPS (Cyber Physical System) using wireless communication sensor and elderly people who disabilities are transmit the information comfortably, Also doctors in correspondent site are able to improves the accuracy of the medical treatment by received information about biometric and audio communication. In addition Health status information is stored selectively and then doctor can check the elders status everytime and everywhere. In this paper, we designed the telemedicine system suitable for korea aging society situation, therefore we could offer the Elderly-friendly medical service for seniors who live in silver town.

• The Transactions of the Korea Information Processing Society
• /
• v.4 no.8
• /
• pp.2080-2091
• /
• 1997

It is generally recognized that Video On Demand (VOD) service will become a promising interactive service in the emerging broadband integrated services digital networks. A centralized VOD system, all programs are stored in a single VOD server which is linked to each user via exchanges, is applicable when a small number of users enjoys the VOD service. However, in case of large service penetration, it is very important to solve the problems of bandwidth and load concentrating in the central video server(CVS) and program transmission network. In this paper, the architecture of the video distribution service network is studied, then a traffic characteristics and models for VOD system are established, and proposed program allocation method to video servers. For this purpose, we present an analysis of program storage amount in each LVS(Local Video Server), transmission traffic volume between LVSs, and link traffic volume between CVS and LVSs, according to changing the related factors such as demand, the number of LVS, vision probability, etc. A method for finding out storage capacity in LVSs is also presented on the basis of the tradeoffs among program storage cost, link traffic cost, and transmission cost.

• Korean Journal of Remote Sensing
• /
• v.13 no.1
• /
• pp.31-46
• /
• 1997

In recent years, as remotly-sensed image processing technologies have been improved and spread widely in the application areas, many new requirements for the image processing technologies have arisen. However, it is difficult and costly to access remotely-sensed image processing systems. Moreover, these systems have thier own processing facilities which are not easily accessible for general users. In this paper, those problems are challenged by adopting Internet as a universal information network for accessing remotly-sensed image DBMS and by allowing users to work remotely on the image processing. A remotly-sensed image processing system which can be accessed via Internet was designed and implemented. This system can be used to manipulate images over remote DBMS. The Illustra object-oriented relational DBMS with CGI(Common Gateway Interface) web interface was used in this project. The client consists of a WWW(World Wide Web) Netscap$e^{TM}$ browser, and the server consists of HTTPD(Web daemon), Illustra DBMS and Java modules in order to process the image being displayed. The developed system was tested on LAN environment and the service response time met the requirements.