• Korean Journal of Social Welfare
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• v.63 no.3
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• pp.5-27
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• 2011

This study was based on the 'Escape Theory' model suggested by Baumeister(1990). Based on this analysis framework, this study attempted to examine that complicated direct and indirect effect of school risk factors(risk of academic scores, risk of relation with teacher and risk of peer relation) on suicide ideation in adolescence, through negative self-esteem, depression and withdrawal coping. To this end, this study used the data from the '2008 Gyeongsangbuk-Do youth crisis survey' conducted by the Youth service center in province of Gyeongsangbuk-Do. The target number of this study was 2,335 students in the age group of middle school and high school. The result of the Analysis indicate that risk of relation with teacher among school risk factors was only one which affected directly and indirectly on suicide ideation. The other side, risk of academic scores and risk of peer relation had indirect effects, via negative self-esteem, depression and withdrawal coping. In conclusion, this study confirmed that school risk factors had effects on suicide ideation directly or indirectly, they were complicatedly connected, through negative self-esteem, depression and withdrawal coping. Therefore, Prevention program for adolescence' suicide ideation or suicide risk require integrated strategies and tactics.

• Journal of Space Technology and Applications
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• v.3 no.3
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• pp.280-300
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• 2023

This paper includes the development and operational status of the space object collision risk management system operated by the Korea Aerospace Research Institute. Currently, it monitors 6 low-orbit satellites and 3 geostationary satellites for collision risks 24 hours, enabling prompt collision avoidance maneuvers to ensure safe and stable operations. Since Chinese anti-satellite test (ASAT) in 2007, the monitoring of collision risks between space objects and operational satellites has been taken seriously, leading to the development of various collision risk management systems to respond quickly and efficiently to such situations. This paper provides an introduction to the space object collision risk management system developed from 2007 to the present, the current status of artificial space objects around Earth, and the system currently in operation. Additionally, it outlines future prospects and plans for the system.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.264-264
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• 2019

The purpose of this paper is to establish development concepts for a novel collision avoidance system with preventing function of navigator's human error (Hu-CAS) in ship control behaviors. Hu-CAS consists of four modules: 1) collision risk assessment module to estimate collision priority between the ship and objects, 2) decision-making module to decide collision risk levels, 3) parameter estimation module needed in the ship control to avoid collisions and 4) control system to control the rudder angle and speed. Hu-CAS, proposed in this paper, can provide a novel system substitution current Autopilot and/or a CAS be teen manned vessel and Autonomous ship in a future.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2014.10a
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• pp.125-127
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• 2014

본 논문은 선박의 일대다 충돌상황에서 국제해상충돌예방규칙(COLREGs, International Regulations for Preventing Collisions at Sea, 1972)을 만족하도록 피항경로를 생성하는 충돌회피 알리고즘의 개발과 적용에 관해 기술한다. 본 연구에서 제안하는 알고리즘은 조우선박의 상대 방위각, 충돌위험정도 및 상호시계와 제한시계의 시계상태에 따라 피항동작을 분류하고, 규칙기반형태의 전문가시스템인 CLIPS(C Language Integrated Production System)를 이용하여 국제해상충돌예방규칙에 따른 피항행동공간을 생성한다. 검증을 위하여 Izuma problems의 3가지 충돌상황을 가정한 컴퓨터 시뮬레이션을 수행하였으며, 다양한 충돌상황에 대하여 안전한 충돌회피경로가 생성됨을 확인 할 수 있었다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.265-269
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• 2006

본 논문에서는 간헐성 카오스를 이용한 장해물 회피 문제를 다루었다. 본 본문은 Chua's 방정식을 이용한 카오스 회로를 이동 로봇에 내장하여 카오스 이동 로봇을 구성하고 이 카오스 이동 로봇이 어느 임의 평면을 카오스 궤적을 가지고 주행하다가 고정 장애물, 또는 은닉 이동 장애물을 만나면 이를 회피하는 알고리즘을 제시하였다. 간헐성 카오스 로봇의 장애물 회피의 경우 고정 장애 and, 이동 장애물, 장애물 위험에 따른 로봇의 접근 등에서 잘 회피됨을 확인하였으며 만족할 만한 결과를 얻었다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.81-86
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• 2003

The studies on automatic ship collision avoidance system, which have been carried out last 10 years, are facing on new situation due to newly developed high technology such as computer and other information system. It was almost impossible to make it used in real navigation 3-4 years ago because of the absence of the tool to get other ship's information, however recently developed technology suggests new possibility. This study is carried out to develop the algorithm of automatic ship collision support system. The NOMOTO ship's mathematic model is adopted in simulation for its simplicity. The fuzzy reason rules are used for course-keeping system and for the calculation of Collision Risk using TCPA/DCPA. Moreover‘encounter type’ between two ships is analyzed based on Regulations for Preventing Collisions at Sea and collision avoidance action is suggested, Some situations are simulated to verity the developed algorithm and appropriate avoidance action is shown in the simulation.

• Journal of Navigation and Port Research
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• v.27 no.4
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• pp.375-381
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• 2003

The studies on automatic ship collision avoidance system, which have been carried out last 10 years, are facing on new situation due to newly developed high technology such as computer and other information system. It was almost impossible to make it used in real navigation 3-4 years ago because of the absence of the tool to get other ship's information, however recently developed technology suggests new possibility. This study is carried out to develop the algorithm of automatic ship collision support system. The NOMOTO ship's mathematic model is adopted in simulation for its simplicity. The fuzzy reason rules are used for course-keeping system and for the calculation of Collision Risk using TCPA/DCPA. Moreover ‘encounter type’ between two ships is analyzed based on Regulations for Preventing Collisions at Sea and collision avoidance action is suggested. Some situations are simulated to verity the developed algorithm and appropriate avoidance action is shown in the simulation.

• Environmental and Resource Economics Review
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• v.17 no.4
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• pp.845-873
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• 2008

This study estimates the VSL(value of a statistical life) as well as the WTP(willingness to pay) for mortality risk reduction using sample selection model with data on liver cancer examination which is associated with little possibility of multi-purpose(i.e. joint production) in averting behavior. The marginal benefits of mortality risk reduction are estimated by applying for household production function model with medical expense and the time required for medical examination of liver cancer. Individuals are more likely to take liver cancer test if they are male, older, higher educated, those with spouse, smoker, more income of household, and more anxious about their health. The costs of liver cancer examination are statistically significantly affected with expected signs by size of mortality risk reduction, sex, period of eduction, those with spouse, and household income. The marginal effect of mortality risk reduction owing to taking liver cancer examination is estimated at 321,097 won. The costs of liver cancer examination are increased by 905 won with more one year of education period and by 1,743 won with more one million won in household income. On liver cancer examination, male spends more 12,310 won than female and those with spouse pay more 7,969 won than those without spouse. Therefore the VSL from mortality risk reduction due to liver cancer examination is 321.10 million won at mean size of mortality risk reduction and mean cost of liver cancer examination. The results of sensitivity tests on costs and effects of liver cancer test shows that the VSLs are estimated in a range from 160.55 million won to 642.19 million won.

• 해운
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• s.84
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• pp.10-16
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• 2011

2002년 이후 지속되어온 미국의 재정적자가 금융위기 중 확대되면서 미국 국가채무가 2012년에는 GDP를 초과할 것으로 전망된다. 미 의회는 5개월 이상 협상을 지속한 결과 2011년 8월 1일 국가채무 한도 상향조정을 포함한 예산통제법을 통과시켜 국가부도사태는 발발하지 않았다. 이러한 미 의회의 국가채무 한도 상향 조정에도 불구하고, S&P는 지난 8월 3일 미국의 국가신용등급을 AAA에서 AA+로 강등하였으며, 주식시장의 경우도 미국의 재정지출 감축으로 인한 경기회복지연, 신용등급 강등 영향으로 인한 국제금융시장의 위험자산 회피현상으로 급락하였다. 미국 재정지출 감축과 위험자산 회피현상에 따른 우리나라의 국내총생산 감소는 미미할 것으로 분석되지만, 재정긴축 계획으로 향후 5년 동안 미국 경제에 평균 -0.5%정도의 GDP 감소 효과가 있으며, 우리나라 GDP도 평균적으로 -0.02% 정도 감소시킬 것이다. 이에 따라 우리나라 기업들도 미국 재정긴축 및 신용등급 강등으로 인하여 발생할 수 있는 사항들을 다각적으로 분석하여 대처를 할 필요성이 제기되고 있다. 다음은 대외경제정책연구원에서 발표한 "미국 재정긴축 및 신용등급 강등의 효과분석"의 주요 내용을 정리 요약한 것이다.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.04a
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• pp.1017-1019
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• 2014

자본주의의 꽃이라 할 수 있는 주식시장은 기업의 정량화된 가치를 매매하는 곳이다. 또한 파생거래는 주식시장의 위험회피 목적으로 만들어졌다. 파생시장이 투기적인 목적으로 악용되기도 하지만 기관투자가에게는 헤지거래의 중요한 수단임은 명백한 사실이다. 파생거래에서 옵션 거래는 투기적인 성향의 개인 거래자와 시장을 선도하는 기관 거래자 간의 치열한 대결로 볼 수 있다. 옵션은 상품별로 시시각각 변하는 이론가와 실거래가가 존재한다. 이론가를 기준으로 한 이격도 매매는 레버리지가 큰 옵션 거래에서 효과적인 위험회피 방법이다. 하지만 이론가는 현실적인 시장가와 괴리가 있을 수밖에 없다. 보다 현실적인 평균값을 구하기 위해서는 실제 옵션가의 통계만이 확실한 방법이다. 이를 위해서 옵션 만기일에 상품별로 차트정보를 수집하여 데이터베이스화하면 효과적이다. 이는 매우 반복적인 작업으로 이를 효과적으로 수행할 수 있는 에 이전트를 개발하였다. 이를 이용하면 실거래가를 기본으로 하는 평균값을 추출할 수 있으며, 지수차이와 잔여일에 따른 옵션 평균값에 근거하여 이격도 매매에 활용할 수 있다.