• Nuclear Engineering and Technology
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• v.27 no.4
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• pp.562-570
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• 1995

The recent ABB/CE(Asea Brown Boveri Combustion Engineering) type pressurized oater reactor-s have the on-line monitoring system, i.e., the COLSS(core operating limit supervisory system), to prevent the specified acceptable fuel design limits from being violated during normal operation and anticipated operational occurrences. One of the main functions of COLSS is the on-line monitoring of the DNB(departure from nucleate boiling) overpower margin by calculating the MDNBR(mini-mum DNB ratio) for the measured operating condition at every second. The CETOP-D model, used in the MDNBR calculation of COLSS, is benchmarked conservatively against the TORC mod-el using an inlet flow factor of hot assembly in CETOP-D as an adjustment factor for TORC. In this study, a technique to optimize the CETOP-D inlet flow factor has been developed by elim-inating the excessive conservatism in the ABB/CE's. A correlation is introduced to account for the actual variation of the CETOP-D inlet flow factor within the core operating limits. This technique was applied to the core operating range of the YongGwang Units 3&4 Cycle 1, which results in the increase of 2％ in the DNB overpower margin at the normal operating condition, compared with that from the ABB/CE method.

• Journal of Chest Surgery
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• v.29 no.9
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• pp.1045-1049
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• 1996

Post-intubation tracheoesophageal fistula is rare, and its management causes a serious problems to surgeons. We have experienced 4 cases in 3 patients. Simple ditcision and closure of the fistulas were done by trans-cervical approach after weaning of ventilator. The tracheal defect was closed by simple suture, and the esophageal defect was closed in two layers before a viable muscle flap was interposed between the two suture lines in order to prevent recurrence. There was one delayed tracheal stenosls and one recurrent fistula, and these complications were also managed success ully.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.5
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• pp.416-422
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• 2013

This paper suggests a hybrid path planning method of multi-robots, where a path deviation prevention for maintaining a specific formation is implemented by using repulsive function, $A^*$ algorithm and UKF (Unscented Kalman Filter). The repulsive function in potential field method is used to avoid collision among robots and obstacles. $A^*$ algorithm helps the robots to find optimal path. In addition, error estimation based on UKF guarantees small path deviation of each robot during navigation. The simulation results show that the swarm robots with designated formation successfully avoid obstacles and return to the assigned formation effectively.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10c
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• pp.295-297
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• 2004

무선 ad-hoc 네트워크란 기반 시설의 도움 없이 노드들 간의 수평적인 통신을 제공하는 임시적인 네트워크이다. 이러한 네트워크 환경에서는 각 노드의 네트워크 창가 밀 이탈이 동적으로 가능하다. 현재 이러한 환경에서 높은 이동성을 지원하는 동시에 라우팅 오버헤드를 최소화하는 연구가 활발히 진행되고 있다. 기존에 제안된 무선 ad-hoc 라우팅 프로토콜들은 부하균형 메커니즘을 지원하지 않으므로 특정 노드에 많은 부하가 발생할 수 있다. 이로 인해 종단 간 지연시간이 길어지며 네트워크의 신뢰성이 낮아질 수 있다. 본 논문에서는 이러한 문제의 해결을 위해 각 노드가 자신의 부하를 측정하고, 경로 요청 시 노드의 부하 정보를 이용해서 부하가 적은 경로를 선택하도록 한다. 또한 데이터 전송 중에 해당 경로의 부하를 확인하여, 보조 경로를 이용하거나 새로운 경로를 검색하여 경로의 혼잡을 해결함으로써 종단 간 지연시간 및 네트워크의 신뢰성을 향상시키는 기법을 제안한다. 본 논문에서 제안하는 기법은 특정 노드에 라우팅 오버헤드가 집중되는 것을 방지하며 이로 인해 종단 간 지연시간을 줄이고 네트워크의 신뢰성 을 향상시킨다.

• Korean Management Science Review
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• v.21 no.3
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• pp.85-99
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• 2004

The retention of customer is an increasingly pressing issue in today's competitive environment. The proposes of this paper is a personalized defection detection and the procedure of prevention based on economic analysis of customer defection possibility, and behaviour state transition cost. This procedure is based on the observation that potential defectors have a tendency to take a couple of months or weeks to gradually change their behaviour before their eventual withdrawal. In this procedure, the SOM(Self-Organizing Map) is used to determine the possible states of customer behaviour from past behaviour data, and to prevent the defection of potential defectors, the proposed procedure recommends the desirable behaviour state for the next period based on the analysis of transition cost. and likelihood of defection. The case study has been conducted for a Korean on-line game provider to evaluate of this procedure.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.2
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• pp.198-210
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• 1999

산업 및 통신기술이 급속히 발전함에 따라, 다양한 형태의 침입기법을 통해 클라이언트-서버 구조의 정보 공유 및 서비스 개념으로 운영되는 시스템상에서 중요한 정보에 대한 유출 및 파괴로 인한 역기능이 심각할 정도로 증가하고 있다. 따라서, 정보시스템에서의 정보의 불법유출을 방지하고 문서나 시스템에 대한 불법행위를 감지할 수 있는 감사추적 기법이 요구된다. 이 논문에서는 능동데이타베이스의 능동규칙을 기존 기법보다 효과적으로 침입자를 감지할수 있는 새로운 감사추적 및 분석시스템 모델을 제안하였다. 이 모델은 시스템사용자에 의해서 발생되는 감사자료의 비정상 여부를 판단할수 있는 기법과 유형별 침입자를 감지하는 알고리즘을 제시하여 정상적인 사용자의 이탈된 행동을 판단할 수 있는 바업을 제시한다.

• Journal of the Korean Society for Library and Information Science
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• v.36 no.2
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• pp.25-38
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• 2002

Libraries today have to investigate the methods connecting the results from continuously collected customer information with their activities, policies, and procedures. In other to prevent customer secession and to obtain new customers, it is necessary to effectively offer the processes for every customer related service, that is, the contact, the reguest, satisfaction, etc. This is Customer Relationship Management(CRM). This study aims to introduce the concept, the constitution elements, and theories for importation and application of CRM, and to investigate the possibility for library application. Also, it is emphasized the necessity for new marketing strategy Putting the customer value Preferentially in libraries.

• Science of Emotion and Sensibility
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• v.10 no.3
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• pp.321-330
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• 2007

The objective of this study is to increase the credibility of online board game and to improve the process of user management system to resolve the negative and time consuming complaints of 'intended game over' caused by other online users who arbitrary stop the game. The suggested system would create profits to company with less investment in time and expenses regarding the forced game over through the online realtime game management system.

• Proceedings of the KIEE Conference
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• 2002.07d
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• pp.2770-2773
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• 2002

본 논문은 지능형 안전 자동차(ASV)의 범주인 차선이탈경보 및 방지시스템에 적용을 위한 차선검출 알고리즘을 나타낸다. 그러기 위해서는 차선검출의 높은 신뢰도가 우선 되어야 한다. 대부분의 고속도로는 직선로와 곡선로로 이루어져있고, 곡선 도로는 차선을 검출하는데 여러 가지 제약이 있다. 본 논문에서는 곡선 차선의 직선 근사화를 통한 신뢰성 있는 차선 검출을 위해서 입력되는 연속영상의 효율적인 처리 기법을 제안하고자 한다.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1021-1023
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• 2000

This paper presents the preventive measure and the cause for field coils breaking away from the rotor, which lately occurred when No.1 hydro generator was operating in Chung-Ju Dam No.2 Hydro Power Station. In findings, we ascertained the truth of contact between rotor rim and field coils, and think that field coils will break away from the rotor because of mechanical stress according as continuous operation after completion. 1985. Therefore, we conclude that the preventive measure for such a phenomenon is that stopper should be installed between rotor rim and field coils, and bolts should be tightened because of operating characteristic however there are not the design standards for installing stopper in generator rotor internationally.