• Proceedings of the Korea Information Processing Society Conference
• /
• 2015.10a
• /
• pp.400-401
• /
• 2015

해상 교통 관제를 함에 있어서 선박간의 충돌 사고를 미연에 방지하기 위해 관제사의 의사 결정을 도울 수 있는 기술들이 많이 개발되고 있다. 관제 시 선박간의 충돌 위험을 판단하고 사고를 미연에 방지하기 위해, 관제사들이 가장 빈번하게 사용되는 기능이 CPA와 거리/방위각 측정기능이다. 하지만, 기존 해상관제 시스템들은 이러한 기능들이 독립적으로 구성되어 있어, 관제사들의 신속한 업무 처리를 방해할 뿐만 아니라, 관제사의 업무 피로도를 종종 증가시킨다. 본 논문에서 제안한 방법은 관제사 설문조사를 통해 수렴된 내용을 토대로 기존의 CPA, 거리/방위각 측정 기능을 보완하여 CPA 계산 시 선박 조우 정보를 제공하고, 관제사로 하여금 충돌예상 선박들에 대해 신속한 초동 조치 지시를 가능하게 한다.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.26 no.1
• /
• pp.8-14
• /
• 2020

According to the statistics provided by Korean Maritime Safety Tribunal for the year 2018, the majority of marine accidents in the past four years have occurred in fishing boats and small-sized boats. Negligent behavior resulting from not looking outside and non-compliance with navigation laws are the primary reasons behind ship collisions. Although safety education and training are reinforced to prevent such accidents, they still occur frequently. Hence, technical methods are continuously being developed to reduce ship collisions caused by human cause. The objective of this study is to reduce ship collisions by employing the WAVE communication system, which has short transmitting and receiving periods that can be incorporated for high-speed small-sized vessels. In this study, the suitability of the communication range was examined, and the appropriate range and timing for avoidance motion were accordingly selected, and a control algorithm based on the same was thereby designed. Consequently normal operation of the collision avoidance system was verified by connecting and simulating the proposed WAVE communication router-controller-steering equipment.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.16 no.1
• /
• pp.90-100
• /
• 2017

This paper investigates pedestrian-thrown distance pattern by pedestrian-vehicle collision position by madymo-simulation. The simulation were performed for every 2.5 cm interval between center and edge of bumper for various vehicle speeds and vehicle shapes. As a result, two critical points where thrown distance change rapidly were found. First critical point locate where pedestrian's shoulder do not contact the vehicle. Second point locate where the center of gravity of pedestrian are close to edge of bumper. Between 1st and 2nd critical points, thrown distance decrease rapidly where collision points move to the edge of vehicle. In other cases, the thrown distance does not change rapidly. This result gives more accurate guideline for pedestrian collision in traffic safety.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.34 no.3
• /
• pp.137-149
• /
• 2021

Cable-stayed bridges are infrastructure facilities of a highly public nature; therefore, it is essential to ensure operational safety and prompt response in the event of a collapse or damage caused by natural and social disasters. Among social disasters, impact accidents can occur in bridges when a vehicle collides with a pier or when crashes occur due to aircraft defects. In the case of offshore bridges, ship collisions will occur at the bottom of the pylon. In this research, a procedure to evaluate the structural behavior of a cable-stayed bridge for aircraft impact is suggested based on a numerical analysis approach, and the feasibility of the procedure is demonstrated by performing an example assessment. The suggested procedure includes 1) setting up suitable aircraft impact hazard scenarios, 2) structural modeling considering the complex behavior mechanisms of cable-stayed bridges, and 3) structural behavior evaluation of cable-stayed bridges using numerical impact simulation. It was observed that the scenario set in this study did not significantly affect the target bridge. However, if impact analysis is performed through various scenarios in the future, the load position and critical load level to cause serious damage to the bridge could be identified. The scenario-based assessment process employed in this study is expected to facilitate the evaluation of bridge structures under aircraft impact in both existing bridges and future designs.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.35 no.2
• /
• pp.93-100
• /
• 2022

The collision behaviors of the tripod and jacket structures, which are considered as support structures for offshore wind towers at the Southwest sea of Korea, were compared by nonlinear dynamic analysis. These structures, designed for the 3 MW capacity of the wind towers, were modeled using shell elements with nonlinear behaviors, and the tower structure including the nacelle, was modeled by beam and mass elements with elastic materials. The mass of the tripod structure was approximately 1.66 times that of the jacket structure. A barge and commercial ship were modeled as the collision vessel. To consider the tidal conditions in the region, the collision levels were varied from -3.5 m to 3.5 m of the mean sea level. In addition, the collision behaviors were evaluated as increasing the minimum collision energy at the collision speed (=2.6 m/s) of each vessel by four times, respectively. Accordingly, the plastic energy dissipation ratios of the vessel were increased as the stiffness of collision region. The deformations in the wind tower occurred from vibration to collapse of conditions. The tripod structure demonstrated more collision resistance than the jacket structure. This is considered to be due to the concentrated centralized rigidity and amount of steel utilized.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.29 no.5
• /
• pp.462-469
• /
• 2023

In this study, we propose a method for evaluating the risk of collision between ships to support determination on the risk of collision in a situation in which ships encounter each other and to prevent collision accidents. Because several uncertainties are involved in the navigation of a ship, must be considered when evaluating the risk of collision. We apply the Dempster-Shafer theory to manage this uncertainty and evaluate the collision risk of each target vessel in real time. The distance at the closest point approach (DCPA), time to the closest point approach (TCPA), distance from another vessel, relative bearing, and velocity ratio are used as evaluation factors for ship collision risk. The basic probability assignments (BPAs) calculated by membership functions for each evaluation factor are fused through the combination rule of the Dempster-Shafer theory. As a result of the experiment using automatic identification system (AIS) data collected in situations where ships actually encounter each other, the suitability of evaluation was verified. By evaluating the risk of collision in real time in encounter situations between ships, collision accidents caused by human errora can be prevented. This is expected to be used for vessel traffic service systems and collision avoidance systems for autonomous ships.

• Journal of Navigation and Port Research
• /
• v.43 no.6
• /
• pp.377-383
• /
• 2019

Naval ships that are navigating always have the possibility of colliding, but there is no clear maneuvering procedure for collision avoidance, and there is a tendency to depend entirely on the intuitive judgment of the Officer Of Watch (OOW). In this study, we conducted a questionnaire survey when and how to avoid collision for the OOW in a Constant Bearing, Decreasing Range (CBDR) situation wherein the naval ships encountered obstacles. Using the results of the questionnaire survey, we analyzed the CBDR situation of encountering obstacles, and how to avoid collision in day/night. The most difficult to maneuver areas were Pyeongtaek, Mokpo, and occurred mainly in narrow channels. The frequency appeared on average about once every four hours, and there were more of a large number of ships encountering situations than the 1:1 situation. The method of check of collision course confirmation was more reliable with the eye confirmation results, and priority was given to distance at closest point of approach (DCPA) and time at closest point of approach (TCPA). There was not a difference in DCPA between the give-way ship and stand-on ship, but a difference between day and night. Also, most navigators prefer to use maneuvering & shifting when avoiding collisions, and steering is 10-15°, shifting ±5knots, and the drift course was direction added stern of the obstacles to the direction of it. These results will facilitate in providing officers with standards for collision avoidance, and also apply to the development of AI and big data based unmanned ship collision avoidance algorithms.

• 한국HCI학회:학술대회논문집
• /
• 2006.02a
• /
• pp.368-373
• /
• 2006

본 연구는 다중 사용자가 존재하는 환경에서 각 사용자의 요구를 만족시킬 수 있는 서비스를 탐색하고, 선택된 서비스를 또 다른 사용자에게 제공되는 서비스와의 충돌 없이 제공하기 위한 서비스 선택 모델을 제안한다. 이 모델은 개별 사용자의 프로파일을 관리하는 사용자 에이전트(User Agent), 환경 정보를 인지하는 센서 매니저(Sensor Manager), 현 환경에 존재하는 기기들의 상태를 관리하는 장치 매니저(Device Manager), 그리고 개별 서비스들 사이의 충돌을 회피하고 서비스를 선택하는 서비스 브로커 (Service Broker) 의 4 가지 타입의 에이전트로 구성되어있다. 사용자 에이전트는 사용자의 과거 행동 정보로부터 사용자의 선호 패턴 및 프로파일을 추출해 낸다. 센서 매니저는 현재 환경에 존재하는 센서들로부터 전달받은 환경 정보를 조합함으로써, 현재 상황을 특징 짓는다. 사용자 에이전트와 센서 매니저로부터 현재 사용자의 특성과 현재 상황 정보를 전달 받은 서비스 브로커는 그 사용자가 현재 상황에서 어떠한 서비스를 필요로 하고 있는지 판단한다. 서비스 선택은 인지된 현재 상황에서 수행 가능한 서비스 목록 중에서, 사용자의 선호도 및 프로파일에 의해 적절한 서비스가 선택 된다. 이렇게 선택된 서비스는 그 서비스를 제공하기 위한 장치들의 작동을 제어함으로써 사용자에게 제공된다. 서비스를 위한 장치를 선택하고, 작업을 할당하기 위해 서비스 브로커는 장치 매니저를 통해 현재 사용 가능한 장치들의 상태와 제공하려는 서비스와 충돌을 일으킬 수 있는 장치들의 상태 정보를 받아와 서비스를 위한 최적의 장치들을 선택하고 동작에 대한 제어 정보를 작성한다. 이렇게 만들어진 서비스 제공 계획은 장치 매니저에게 전달되고, 장치 매니저는 계획에 따라 실제 장치들을 제어한다. 이상의 다중 에이전트 모델을 통해, 특정 상황에 존재하는 사용자 개개인에게 특성화된 서비스를 충돌 없이 제공할 수 있다.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.20 no.3
• /
• pp.113-118
• /
• 2012

Collision detection plays a key role in collision mitigation system. The malfunction of the collision mitigation system can result in another dangerous situation or unexpected feeling to driver and passenger. To prevent this situation, the collision time, offset, and collision decision should be determined from the appropriate collision detection algorithm. This study focuses on a method to determine the time to collision (TTC) and frontal offset (FO) between the ego vehicle and the target object. The path prediction method using the ego vehicle information is proposed to improve the accuracy of TTC and FO. The path prediction method utilizes the ego vehicle motion data for better prediction performance. The proposed algorithm is developed based on laser scanner. The performance of the proposed detection algorithm is validated in simulations and experiments.

• The Journal of the Petrological Society of Korea
• /
• v.23 no.4
• /
• pp.293-309
• /
• 2014

The Qinling-Dabie-Sulu-Hongseong-Odesan collision belt was formed by the collision between the North China and South China Cratons during late Permian to Triassic. During the collision, Triassic post-collision igneous rocks regionally intruded in the Qinling and the Hongseong-Odesan collision belts which represent the western and eastern ends of the collision belt, respectively. However, no and minor Triassic post-collision igneous activities occur in the Dabie and Sulu belts respectively. The peak metamorphic pressure conditions along the Qinling-Dabie-Sulu-Hongseong-Odesan belt indicate that the slab break-off occurred at the depth of ultra-high pressure (UHP) metamorphic condition in the Dabie and Sulu belts and at the depths of high pressure (HP) or high pressure granulite (HPG) metamorphic condition in the Qinling and Hongseong-Odesan belts. In the Dabie and Sulu belts the heat supply from the asthenospheric mantle through the gab formed by slab break-off could not cause an extensive melting in the lower continental crust and lithospheric mantle directly below it due to the very deep depth of slab break-off. On the other hand, in the Qinling and Hongseong-Odesan belts, shallower slab break-off caused the emplacement of regional post collision igneous rocks. The post-collision igneous rocks occur in the area to the north of the Mianlu Suture zone in the western Qinling belt and crop out continuously eastwards into the areas to the north of the Shangdan Suture zone in the eastern Qinling belt through the areas within the South Qinling block. This distribution pattern of post collision igneous rocks suggests that the Triassic collision belt in the Mianleu Suture zone may be extended into the Shangdan Suture zone after passing through the South Qinling block instead into the boundary between the South Qinling block and the South China Craton.