• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.12 no.1
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• pp.20-25
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• 1998

This paper presents an algorithm for contingency ranking using line outage distribution factors(LODF) which are established by generation shift distribution factors(GSDF) from DC load flow solutions. By using the LODF, the line flow can be calculated according to the modification of base load flow if the contingency occur. To obtain faster contingency ranking, only the loading line more than 35[%](60[%] at 154[kV]) is included in the computation of Performance Index(PI). The proposed algorithm has been validated in tests on a 6-bus test system.system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2023.05a
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• pp.290-291
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• 2023

Outlier(이상치) 분석을 통한 등부표 선회안전반경 정보 제공에 관한 연구는 AIS 또는 RTU가 설치된 등부표에 대한 이탈 위험 인지, 항해안전 사고 예방 등 안전대책을 강화하기 위한 연구이다. 등부표는 조류, 바람 등 외력에 의해 이출거리가 발생하여 일정한 패턴으로 선회반경이 형성되나 외력으로 인하여 정상범위에서 벗어나 유실, 위치이동 등이 발생할 수 있고 이는 선박추돌 등 항해안전 사고로도 이어질 수 있다. 이러한 등부표 사고는 물적 피해비용과 이용자의 안전운항에 대한 심리적 부담감 또는 위험감수 등의 추가적인 행정소요 비용이 발생할 수 있다. Outlier(이상치)란 외력 등으로 인해 최대 이출거리 이내 정상범위에서 벗어나거나 존재할 수 없는 극단적인 위치 값으로써 21년도 등부표 위치 데이터를 일정 단위 방위별로 분석해 본 결과 Outlier(이상치)가 식별되었다. 따라서 등부표의 안전한 위치 상태를 시스템적으로 모니터링 하기 위해 Outlier(이상치) 분석을 통한 등부표 선회안전반경 정보 제공에 관한 연구를 하였다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.10a
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• pp.86-91
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• 2003

원자력발전소의 설계는 다중방호의 개념에 의해 이루어져, 그 구조가 복잡하고 운전 형태도 다양하며, 이에 따라 사고의 전개 과정도 다양하게 나타난다. 이로 인해 원자력발전소의 운전원들은 발전소의 유동적인 상황에 대처할 수 있는 고도의 능력이 요구된다. 특히 주제어실 운전원들은 발전소의 기동 및 전출력 운전, 정지, 그리고 비정상 및 비상 상황 시의 적절한 대처에 대한 책임을 지고 있다. 발전소의 사고 분석 결과에 의하면, 사고에 대한 운전원의 대응이 사고의 전개에 직접적인 영향을 미치게 되며, 결과 적으로 사고에 대한 운전원들의 적절한 대응 능력은 발전소의 안전성에 중요한 부분임이 밝혀졌다.(중략)

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.3
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• pp.654-662
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• 2016

As the number of gates and basic events in fault trees increases, it becomes difficult to calculate the exact probability of the top event. In order to overcome this difficulty the BDD methodology can be used to calculate the exact top event probability for small and medium size fault trees in short time. Fault trees are converted to BDD by using CUDD library functions and a failure path search algorithm is proposed to calculate the exact top event probability. The backward search algorithm is more efficient than the forward one in finding failure paths and in the calculation of the top event probability. This backward search algorithm can reduce searching time in the identification of disjoint failure paths from BDD and can be considered as an effective tool to find the cut sets and the minimal cut sets for the given fault trees.

• 전기의세계
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• v.42 no.2
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• pp.12-22
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• 1993

사고는 잠재적 사고원인에 대한 인식 부족이나 그 위험성을 등한히 함으로써 발생되는 것으로, 절대로 우발적으로 발생되지 않는다. 이 재해 발생 원인인 불안전한 상태 또는 행동은 사전에 발견할 수 있으며, 사고의 가능서은 제거가 가능하다. 그러므로, 전기로 인한 재해를 방지하기 위해서는 전기기기 설치시에는 관련규정에 적합하게 시설함은 물론 만약 기기 사고시에도 인체를 보호할 수 있는 각종 안전장치의 시설을 완비하는 것이 필요하며, 또한, 이와같은 기기가 정상적으로 작동될 수 있도록 평상시 안전점검을 철저히 하고 근로자의 불안전한 행동을 없애기 위하여 안전지식 및 안전의식 고취를 위한 안전교육 실시 등의 재해예방 활동에 만전을 기해야 할 것이다.

• Korean Journal of Psychosomatic Medicine
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• v.18 no.1
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• pp.40-47
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• 2010

Objectives：Body image is closely related to self-esteem and weight-control related behaviors. In particular, relationship between two factors would be stronger in female adolescents. False recognition on body image and weight can be a risk factor of eating disorder, depression, and suicidal ideation. This study aimed to examine the effects of body image and eating disorders on developing depressive symptoms and suicidal ideation in female adolescents. Methods：Two hundred thirty nine students of a Girls' Commercial High School in Seoul were recruited. Eating Attitude Test for Korean Adolescents, Self-Esteem Scales, Impulsiveness Scale, Beck's Depression Inventory and Beck's Suicidal Ideation Scale were used to measure eating attitude and severity of psychiatric symptoms. Results：Among 239 subjects, the estimated risk group of eating disorders was 10%(n=24). They experienced more depressive symptoms than the control group. The bigger discrepancy in current and ideal body mass index was significantly related with higher depressive mood, suicidal idea, abnormal eating habits and lower self-esteem. Discrepancy between current and idea BMI was the most meaningful predictive factor about depression and suicidal thoughts by linear regression analysis. Conclusion：In spite of normal weight range of enrolled subjects, they experienced significant depressive mood, suicide thoughts and lower self-esteem associated with the discrepancy of their own subjective body image and current body mass index. Hence educational approach regarding normal body image and healthy weight control is needed for their mental health and preventing eating disorder.

• Nuclear Engineering and Technology
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• v.26 no.2
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• pp.161-167
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• 1994

This paper presents a concept of a pressure tube-type water-cooled reactor without the emergency core cooling system. It adopts an innovative fuel channel design using metallic fuel matrix to improve heat transfer from fuel to moderator at loss of coolant cooling. The heat produced in the fuel is cooled by the coolant system during normal operation, but by the passive moderator system at loss of coolant cooling including the loss-of-coolant accident(LOCA). Simple analysis shows that the fuel channel temperature can be maintained within the permissible range for both normal operation and a complete LOCA.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.3
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• pp.615-625
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• 2015

This paper proposes new methods and examples for improving fraud detection rules based on banking customer's transaction behaviors focused on anomaly detection method. This study investigates real example that FDS(Fraud Detection System) regards fraudulent transaction as legitimate transaction and figures out fraudulent types and transaction patterns. To understanding the cases that FDS regard legitimate transaction as fraudulent transaction, it investigates all transactions that requied additional authentications or outbound call. We infered additional facts to refine detection rules in progress of outbound calling and applied to existing detection rules to improve. The main results of this study is the following: (a) Type I error is decreased (b) Type II errors are also decreased. The major contribution of this paper is the improvement of effectiveness in detecting fraudulent transaction using transaction behaviors and providing a continuous method that elevate fraud detection rules.

• Journal of Science and Technology Studies
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• v.10 no.2
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• pp.77-105
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• 2010

This essay aims to look into the possibility and limit of a technological fix with the PSD (platform screen door), which was proposed as the solution of subway risk problems. Subway risk problems may be classified into five categories-on-rail accidents, in-station accidents, platform accidents, spatial risks in underground, and risks due to a crime or terror-, and the platform accidents, which happens at the interface between the rail and the station, is the most serious and prominent. The PSD is considered as an effective technical means to prevent platform accidents. However, there remains a possibility of aggravating unexpected and invisible risks. When a fire breaks out in platforms, especially at exchange stations during the rush hour, the PSD can become a "wall of outcrying", since it may act as the "safety shutter" which killed many people in the 2003 Daegu subway disaster. This is why we need to look into the limit of a technological fix with the PSD.

• Journal of the Korea society of information convergence
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• v.7 no.1
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• pp.25-46
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• 2014

After examining the current situations of financial frauds and the reasons for their occurrence in the financial institutions through examples of financial frauds in domestic and abroad, this study presents ways to prevent such financial scams. The preventive measures consist of activities before and after the occurrence of financial frauds and during normal financial operations. The activities are as follows: 1. Preventive activity should be strengthened before the occurrence of financial frauds. That is, first, the enforcement of consistent internal control is needed. Second, in order to block the probability of financial frauds involved with employees, ethics education and a reward program for inside tippers need to be run. Third, financial institutions need to apply for comprehensive insurance policy to minimize the lost in case. 2. Preventive activity should be strengthened during normal financial operations. First, self authentication system for customers needs to be introduced. Second, dealings of day, week, and month need to be thoroughly checked and the system of audit needs to be expanded. Third, message service for the information on financial frauds and their preventive measures needs to be expanded. Fourth, public notification system against examples of financial frauds needs to be expanded. 3. Preventive activity after the occurrence of financial frauds should be strengthened. First, awareness for preventive measures such as imposing penalty on the manager needs to be enhanced. Second, strict restrictions on financial frauders such as a criminal charge needs to be strengthened. Third, there should be legal devices and resolutions in order to retrieve all the money deceived by financial frauds.