• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1221-1224
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• 2003

비즈니스 룰은 이윤을 획득하기 위한 상용 시스템에서는 반드시 명확하게 기술되어야만 하며 시스템에서 비즈니스 룰의 충돌은 시스템에 대한 신뢰도를 떨어뜨리는 요인이 될 뿐만 아니라, 시스템의 계획 당시에는 예측하지 못했던 크고 작은 경제적인 손실을 발생하게 한다. 일반적으로 비즈니스 룰은 애매모호함을 가지고 있는 비정형 언어로 기술되는 경우가 많아서, 설정된 비즈니스 룰간의 충돌을 예측하기가 매우 어려울 뿐만 아니라, 개발 중에 룰이 추가되는 경우에 기존의 룰과의 충돌을 예측하기란 매우 어려운 일이다. 본 논문에서는 이 문제를 해결하기 정형 명세를 이용한 모델링을 사용하였다. 수학, 논리학에 기반을 둔 정형 모델링 방법으로 비즈니스 룰을 명확하게 표현하고, 해당 룰을 내포한 시스템 모델링을 구현하였다. 그 결과 작성된 비즈니스 룰의 충돌 여부를 판단할 수 있게 되었다. 시스템 개발 초기에 구현 후에 발생할 수 있는 문제를 미연에 발견하여 시스템 모델 혹은 비즈니스 룰의 수정하여 신뢰할 수 있는 시스템을 개발할 수 있도록 도움을 주고자 한다 본 논문에서는 명확한 표현을 위해서 비즈니스 룰을 일차 논리로 기술하고 룰과 모델링을 위해서 일차논리 기반의 정형 명세 언어인 Z 를 사용하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.271-273
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• 2004

태스크포스팀의 구성원들은 이전 조직에서 가졌던 역할 권한과 태스크포스팀으로 파견되어 갖게 되는 역할 권한 등으로 해서 복합적인 접근권한을 갖게 된다. 예를 들어 어떤 사용자가 어떤 객체에 대해 접근이 허가된 접근권한과 접근이 불허된 접근권한을 각각 다른 역할을 통해 갖게 되었음 때 사용자가 객체를 접근 하고자 할 때 이를 허용할 것이지 불허할 것인지 둘 중의 하나를 결정해 주어야 하는데 이를 권한 충돌 해결이라 한다. 권한 충돌 해결을 위해 많은 연구가 있어 왔으나 태스크포스팀과 같은 임시조직과 기존의 관료제 조직이 병존하는 상황에서 어떤 자원에 대한 접근 요구시 시스템에 의해 즉시 권한충돌 문제를 해결해 접근허가 여부를 판단해 줄 수 있는 방법으로는 적합하지 못했다. 본 논문에서는 기존의 관료제 조직과 태스크포스팀 조직과 같이 서로 다른 특성을 갖는 조직이 병존하는 환경에서 발생하는 권한충돌 문제를 해결하고자 한다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.89-94
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• 2004

Up to now a lot of the study on ship collision avoidance systems has proceeded actively. However the frequency of ship collision accidents didn't decreased. If there is collision risk in close quarters situation none the less manouvering ship for collision avoidance according to the system, only use of TCPA and DCPA as input factor for collision risk decision is not useful to avoiding collision action. For the recent 5 years by the analysis of first observation distance about approaching ship in domestic collision accidents, nearly $45\%$ of accidents is close first observation less than 2 miles. Therefor it is essential part for safety navigations to study for collision avoidance action in close encounter. In this paper, as foundation study of supporting collision avoidance manoeuvring for navigators, we proposed ship collision avoidance support model in close quarters situation through analysis of collision accidents for effective getting rid of the causes.

• Journal of the Earthquake Engineering Society of Korea
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• v.15 no.4
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• pp.13-21
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• 2011

Seismic structure pounding between adjacent superstructures may induce the destruction of pier and bridge superstructures and cause local damage that leads to the collapse of the whole bridge system. The pounding problem is related to the expansion of joints, gap distance and seismic response of the abutments. In this research, methods of the contact element approach, the linear spring model, the Kelvin-Voigt model and the Hertz model were studied to analyse the pounding characteristics. The shaking table test for a model specimen such as a bridge superstructure with elastomeric bearings was performed to evaluate the contact element approach methods. Relationships between the time history response from the numerical analysis results and the measured response from the shaking table test are compared. The experimental results were not well matched with the numerical analysis results using the existing pounding stiffness models. Therefore, in this study, coefficients are proposed to calculate the appropriate pounding stiffness ratio.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.827-832
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• 2004

Up to now a lot of the study on ship collision avoidance systems have proceeded actively. However the rate of ship collision accidents hasn't decreased yet. If there is collision risk in close quarters situation in spite of maneuvering ship for collision avoidance according to the system, only use of TCP A and DCP A as input factor for collision risk decision is not useful to avoiding collision action. For the recent 5 years by the analysis of first observation distance about approaching ship in domestic collision accidents, nearly $45\%$ of accidents is close first observation less than 2 miles. Therefore it is essential part for safety navigations to study for collision avoidance action in close encounter. In this paper, as a fundamental study of supporting collision avoidance maneuvering for navigators, we proposed ship collision avoidance support model in close quarters situation through analysis qf collision accidents to effectively get rid of the causes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.604-613
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• 2018

In recent years, numerous train derailment accidents caused by deterioration and high speed technology of railways have increased. Guardrails or barriers of railway bridges are installed to restrain and prevent the derailment of the train body level. On the other hand, it can result in a high casualties and secondary damage. Therefore, a Derailment Containment Provision (DCP) within the track at the wheel/bogie level was developed. DCP is designed for rapid installation because it reduces the impact load on the barrier and inertia force on the steep curve to minimize turnover, fall, and trespass on the other side track of the bridge. In this paper, DCP was analyzed using LS-Dyna with a parameter study as the impact loading location and interface contact condition. The contact conditions were analyzed using the Tiebreak contact simulating breakage of material properties and Perfect bond contact assuming fully attached. As a result, the Tiebreak contact behaved similarly with the actual behavior. In addition, the maximum displacement and flexural failure was generated on the interface and DCP center, respectively. The impact analysis was carried out in advance to confirm the DCP design due to the difficulties of performing the actual impact test, and it could change the DCP anchor design as the analysis results.

• Journal of the Korea Society for Simulation
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• v.25 no.4
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• pp.127-135
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• 2016

Even thought modernized marine navigation devices help navigators, marine accidents has been often occurred and ship collision is one of the main types of the accidents. Various studies on the assessment method of collision risk have been reported, and studies using fuzzy theory are remarkable for the reason that reflect linguistic and ambiguous criteria for real situations. In these studies, collision risks were assessed on the assumption that the current state of navigation ship would be maintained. However, navigators ignore or turn off frequent alarms caused by the devices predicting collision risk, because they think that they can avoid the collisions in the most of situations. This paper proposes a model of predicting ship collision risk considering the general patterns of collision avoidance, and the approach is based on fuzzy inference and discrete event system specification (DEVS) formalism.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.121-123
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• 2017

드론은 군사목적에서 개발되고 사용되어 왔으나 현재에는 촬영, 물류 등의 다양한 분야에서 연구 및 사용되고 있다. 앞으로 수많은 드론이 하늘에서 비행할 것으로 예상됨에 따라 때때로 비슷한 항로를 비행하는 드론간의 충돌 위험 또한 야기될 수 있다. 드론을 안전하게 비행하기 위한 많은 연구들이 진해되어 왔지만 공중 충돌에 의한 피해를 최소화 하려는 연구의 진행은 초기상태에 있다. 본 논문은 민간 항공기에 적용되어 사용되고 있는 1030/1090MHz 대역의 TCAS 시스템을 433MHz LoRa 네트워크를 사용하여 구현하였다. 충돌 위험을 판단하는 근거는 비행준인 드론의 진행 방향 및 비행 고도를 통하여 산출한다.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.353-356
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• 2003

본 논문은 이동로봇의 다양한 작업들 중에 선행하는 물체를 안정하게 추종하는 동작중 예기치 못한 움직이는 장애물의 효과적인 회피 방법을 고려한다. 센서 기반의 이동로보트에서는 이동물체 추종과 충돌회피를 센서정보에 의존해서 해결해야 하는데 동일한 센서 정보로 추종물체와 충돌물체를 구분하는 것이 쉽지 않은 문제이다. 또한 명확히 규정되지 않은 환경에서 적용하기 어렵다. 따라서 본 논문에서는 이와 같이 명확히 규정되지 않은 환경에서 선행물체의 안정한 추종과 추종 중에 마주치는 이동 장애물에 대한 충돌회피를 위하여 이동로봇의 상태 판단에 따라 구분된 행동 선택 모드를 제안하고 실험적으로 확인한다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.6
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• pp.642-648
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• 2019

Vessels sail according to the COLREG to prevent a collision. However, it is difficult to apply COLREG under special situation as heavy traffic, at this time personal skills of the operator are required. In this case, traffic control is required through the maritime traffic monitoring system. Therefore, maritime traffic management is globally implemented by VTS. In this system, VTS of icer uses the VTS system to assess risks and recommends possible safety operation to vessels with radio systems. This study considers that the risk analysis method with AI (Artificial Intelligence) technology from the operator's aspect. In addition, the research explains the Maritime Traffic Safety Monitoring System, Including AR (Augmented Reality) technology to increase vessel control efficiency. This system is able to predict hazards and risk priorities, and it leads to sequential elimination of dangerous situations. Especially, the hazard situations can be analyzed from operator's perspective of each vessel instead of the VTS officer's aspect, which is more practical than the conventional method. Furthermore, the result of analysis enables to comprehend quantitative hazardous areas and support recommended routes to avoid a collision. As a result, I firmly believe that the system will support to prevent a collision in complex traffic waters. In particular, it could be adopted as a collision prevention system for Maritime Autonomous Surface Ship, which occupies a significant proportion in Maritime 4th industrial revolution.