• Journal of the Korean Society of Marine Environment & Safety
• /
• v.2 no.S1
• /
• pp.63-73
• /
• 1996

The assesment of the safety of ship's transit in a curved narrow channl consists of the maneuvering safety determined by the chance of running aground, the maneuvering difficulty determined by shop's workload, and shiphandler's subjective evaluation. In this study to examine the correlation between shiphandler's subjectice evaluation and the maneuvering risk, the real-time and full-mission shiphandling simulator in the Korean Marine Training & Research Institutes(KMTRI) was utilized. In the conning bridge of the shiphandling simulator, 50 experienced masters conducted masters conducted the modeled vessel of 60,000 deadweight tonnage along the designed channel under 3 different envrinmental conditions. The findings were as follows: (1) The frequencies of stress levels, work difficulties, vessel controllability and overall workload of shiphandlers are similar irrespective of environmental conditions and they are able to be represented as shiphandler's subjective evaluation. (2) It is possible to assess and analyze theoretically the correlation between the shiphandler's subjective ecaluation and maneuvering risk each environmental cindition by quantifying the data obtioned from the tests. The results are as follows: ① As the degree of maneuvering risk increases, the shiphandler's subjective evaluation increases sharply near the curvature area of the desgined channel. ② In the area of the curvature of the designed channel, maneuvering risk increases sharply with the danger of running aground under the environmental condition of current and wind comung from the stem.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2017.11a
• /
• pp.8-10
• /
• 2017

최근 빈번한 항해 사고에 대응하여 항해 안전에 대한 관심이 높아지고 있으며 특히 항해중인 선박의 안전 항해에 대한 육상 감시기술 개발에 많은 노력이 기울려 지고 있다. 이러한 육상용 항해안전 감시시스템은 항만 교통 번잡도에 따른 조종 위험성 평가 기능 및 해양기상에 따른 선박 안전성능 평가 기능 등으로 구성되며, 선박 안전성능 평가를 위하여 선박에서 전송되는 AIS정보를 운항정보로 변환하여 구축된 선박별 동특성 정보와 연결한 후 안전성능지수를 도출하는 기술 구현이 필요하다. 본 연구에서는 이러한 항해안전 감시시스템 개발을 위하여 환경 요인에 의한 항해중 선박의 위험 요소를 분석, 항해안전 평가 모델을 개발한 후 개발된 평가 모델에 대한 평가 기준을 제시하였고 각 평가 모델의 결과를 정량적 지수형태로 도출하여 안전항해 감시시스템의 정량적 평가 기능을 지원하였다.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.38 no.1
• /
• pp.79-88
• /
• 2014

Enhancing the working speed and positional accuracy of high-speed press machines is essential for improving the parts accuracy and productivity. However it is known that the positional accuracy decreases and the risk of parts failure increases as the working speed of press machine increases. Therefore predicting such problems during the stage of press structure design is necessary for precise design of high-speed press machines. In the present investigation, the dynamic-elastic deformation of press drive module parts with eccentric masses was examined by finite element analysis and experiment. Then the positional accuracy and parts failure of high-speed press machines was evaluated.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.2 no.1
• /
• pp.35-45
• /
• 1996

The assesment of the safety of ship's transit in a curved narrow channel consists of the maneuvering safety determined by the chance of running aground, the maneuvering difficulty determined by ship's workload, and shiphandler's subjective evaluation. In this study to examine the correlation between shiphandler's subjective evaluation and the maneuvering risk, the real-time and full-mission shiphandling simulator in the Korea Marine Training & Research Institutes(KMTRI) was utilized. On the conning bridge of the shiphandling simulator, 50 experienced masters conducted the modeled vessel of 60,000 deadweight tonnage along the designed channel under 3 different environmental conditions. The findings were as follows : (1) The frequencies of stress levels, work difficulties, vessel controllability and overall workload of shiphandlers are similar irrespective of environmental conditions and they are able to be represented as shiphandler's subjective evaluation. (2) It s possible to assess and analyze theoretically the correlation between the shiphandler's subjective evaluation and maneuvering risk under each environmental condition by quantifying the data obtained from the test. The results are as follows : ① As the degree of maneuvering risk increases, the shiphandler's subjective evaluation increases sharply near the curvature area of the designed channel. ② In the area of the curvature of the designed channel, maneuvering risk sincreases sharply with the danger of running aground under the environmental condition of current and wind coming from the stern.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2018.10a
• /
• pp.166-169
• /
• 2018

캐시 부채널 공격 중 하나인 FLUSH+RELOAD 공격은 높은 해상도와 적은 오류로 그 위험성이 높고, 여러가지 프로그램에서도 적용되어 개인정보의 유출에 대한 위험성까지 증명 되었다. 따라서 이 공격을 막기 위해 실시간으로 감지 할 수 있어야 할 필요성이 있다. 본 연구에서는 4가지 실험을 통하여 이 FLUSH+RELOAD 공격을 받을 때 PCM(Performance Counter Monitor)를 사용해 각각의 counter들의 값의 변화를 관찰하여 3가지 중요한 요인에 의해 공격 탐지를 할 수 있다는 것을 발견하였다. 이를 이용하여 머신 러닝의 logistic regression과 ANN(Artificial Neural Network)를 사용해 결과에 대한 각각 학습을 시킨 뒤, 실시간으로 공격에 대한 탐지를 할 수 있는 프로그램을 제작하였다. 일정한 시간동안 공격을 진행하여 모든 공격을 감지하는데 성공하였고, 상대적으로 적은 오탐률을 보여주었다.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.31 no.2
• /
• pp.46-54
• /
• 2023

Helicopter pilots are required to perform many visual workloads in topographical avoidance, flight path modification and navigation, because helicopters operate at very low altitudes. The helicopter-specific instability also require the pilot to have precise perception and control. This has caused frequent human error in helicopter accidents. In Korea, two to three cases have occurred annually on average over the past 10 years, and this trend has not decreased. The purpose of this study was to identify human error risks in advance to prevent helicopter accidents and to help develop measures for missions and mission phases with high risk of human error. Through the study, the tasks and mission phases where accidents occur frequently were classified and the risk of human error was calculated for each mission phases. To this end, the task of frequent accidents during helicopter missions was first identified, detailed steps were classified, and the number of accidents was analyzed. Next, the AHP survey program was developed to measure the pilot's risk of human error and the survey was conducted on the pilots. Finally, the risk of human error by helicopter mission and by mission phases calculated and compared with the actual number of accidents.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.30 no.1
• /
• pp.74-81
• /
• 2024

In the near future, autonomous ships, ships controlled by shore remote control centers, and ships operated by navigators will coexist and operate the sea together. In the advent of this situation, a method is required to evaluate the safety of the maritime traffic environment. Therefore, in this study, a plan to evaluate the safety of navigation through ship control simulation was proposed in a maritime environment, where ships directly controlled by navigators and autonomous ships coexisted, using autonomous operation technology. Own ship was designed to have autonomous operational functions by learning the MMG model based on the six-DOF motion with the PPO algorithm, an in-depth reinforcement learning technique. The target ship constructed maritime traffic modeling data based on the maritime traffic data of the sea area to be evaluated and designed autonomous operational functions to be implemented in a simulation space. A numerical model was established by collecting date on tide, wave, current, and wind from the maritime meteorological database. A maritime meteorology model was created based on this and designed to reproduce maritime meteorology on the simulator. Finally, the safety evaluation proposed a system that enabled the risk of collision through vessel traffic flow simulation in ship control simulation while maintaining the existing evaluation method.

• Journal of Korean Society of Transportation
• /
• v.35 no.2
• /
• pp.160-168
• /
• 2017

In the past 10 years, the accidents caused by drowsy driving have occupied about 23% of all traffic accidents in Korea expressway network and this rate is the highest one among all accident causes. Unlike other types of accidents caused by speeding and distraction to the road, the accidents by drowsy driving should be managed differently because the drowsiness might not be controlled by human's will. To reduce the number of accidents caused by drowsy driving, researchers previously focused on the spot based analysis. However, what we actually need is a segment (link) and occurring time based analysis, rather than spot based analysis. Hence, this research performs initial effort by adapting link concept in terms of drowsy driving on highway. First of all, we analyze the accidents caused by drowsy in historical accident data along with their road environments. Then, links associate with driving time are analyzed using digital tachograph (DTG) data. To carry this out, negative binomial regression models, which are broadly used in the field, including highway safety manual, are used to define the relationship between the number of traffic accidents on expressway and drivers' behavior derived from DTG. From the results, empirical Bayes (EB) and potential for safety improvement (PSI) analysis are performed for potential risk segments of accident caused by drowsy driving on the future. As the result of traffic accidents caused by drowsy driving, the number of the traffic accidents increases with increase in annual average daily traffic (AADT), the proportion of trucks, the amount of DTG data, the average proportion of speeding over 20km/h, the average proportion of deceleration, and the average proportion of sudden lane-changing.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.23 no.2
• /
• pp.47-53
• /
• 1987

Many studies are conducted to evaluate the risk of maneuvering ships in the congested harbours and narrow channels. These studies are very important for the prevention of sea traffic accidents in those sea areas. In this paper, the author carried out a series of observations on sea traffic condition of the vessels entering and leaving the harbour of CHUNG MU, in order to evaluate the risk of grounding, the margin and burden of route keeping maneuver of vessels proceeding along the fairway of this harbour. The results obtained are as follows: 1. The grounding risk indices for the east bound and west bound vessels at the middle part and western part of the fairway were higher than those of them at the eastern part. 2. The margin of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for the east bound vessels, and the highest at the middle part for the west bound vessels, but the lowest at the western entrance for both of them. 3. The burden of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for both of the east bound and west bound vessels, but the lowest at the eastern part for both of them. 4. The influence of maneuvering indices T' on the grounding risk indices appeared to be larger than that of maneuvering indices K' on them.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.23 no.2
• /
• pp.1-1
• /
• 1987

Many studies are conducted to evaluate the risk of maneuvering ships in the congested harbours and narrow channels. These studies are very important for the prevention of sea traffic accidents in those sea areas. In this paper, the author carried out a series of observations on sea traffic condition of the vessels entering and leaving the harbour of CHUNG MU, in order to evaluate the risk of grounding, the margin and burden of route keeping maneuver of vessels proceeding along the fairway of this harbour. The results obtained are as follows: 1. The grounding risk indices for the east bound and west bound vessels at the middle part and western part of the fairway were higher than those of them at the eastern part. 2. The margin of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for the east bound vessels, and the highest at the middle part for the west bound vessels, but the lowest at the western entrance for both of them. 3. The burden of route keeping maneuver in the fairway appeared to be the highest at the western part of the fairway for both of the east bound and west bound vessels, but the lowest at the eastern part for both of them. 4. The influence of maneuvering indices T' on the grounding risk indices appeared to be larger than that of maneuvering indices K' on them.