• Title/Summary/Keyword: Safe distance

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A Study on the Minimum Safe Distance Index of Filipino Navigators in the Vicinity of Obstacles and in Adverse Weather Conditions

  • Dimailig, Orlando S.;Jeong, Jae-Young
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.3
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    • pp.250-257
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    • 2017
  • This paper investigates minimum safe distances relative to a ship's four cardinal sides, as perceived by Filipino navigators when encountering dangerous elements and in adverse weather conditions when maneuvering in and around harbors. It uses a descriptive research method in the form of a questionnaire survey for experienced Filipino navigators of various ranks. During the course of research, 71 responses were colleted and the resulting data is presented in graphical and tabulated forms. Statistical methods including Pearson-product moment correlations, Cronbach's Alpha and ANOVA were used to identify internal associations, consistencies and significances, respectively. It has been proven that there are no significant differences in minimum safe distances relative to a ship's four cardinal sides, whether maneuvering while approaching a port or within an inner harbor. This study has been deemed significant for training future navigators, managing traffic in fairways, and designing harbors and maneuvering areas in the approaches to ports, among other applications. This work can also be used as a preliminary study for comparison with the well known safe domains presently in use.

A Study on the Application of Reaction Time and Detailed Security Response (신체반응시간과 근접경호 대응논리 적용에 관한 연구)

  • Lee, Choong-Soo
    • Korean Security Journal
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    • no.15
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    • pp.303-316
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    • 2008
  • One of important protecting skill is securing the minimum safe distance from potential hazard to protect protectee in the emergency situation, that is basic thing for the detailed security in relation to the walking formation and the distance between protectee and crowed. This thesis is to provide the idea on the scientific countermeasure in the gun attack situation, by presenting logic on the reaction time and it's moving distance, on the safe distance between protectee and crowed. Handball goal keeper's reaction time of 0.33seconds is applied, because handball goal keeper's reaction style is very similar to security agent's reaction style. And 4m/sec of record is applied, that is average speed of 'go and return type run of 40m' to calculate it's moving distance. Several researches show that reaction time could be improved by continuing training, similarly security agents could improve their reaction time, providing better reaction skill. The important thing is that it make big difference in the protecting result, although the shortening of reaction time is too slight. Securing safe distance between protectee and crowed and the distance between protectee and security agent could provide effective reaction environment with 'natural protective wall effect' by security agent

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Derivations of Positive Pressure Condition for Development of Foldable Safe Pathway in Railway Tunnel Fires (철도터널화재용 접이식 대피통로 개발을 위한 양압 조건 도출)

  • Kim, JiTae;Ro, Kyoungchul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.284-289
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    • 2019
  • The Korea Foldable safe pathway system is an evacuation support system to get temporary evacuation route in railway tunnel and large space fires. A prevention smoke screen is unfolded in fires and it is needed to prevent heat and smoke from fire source. Therefore, ventilation system for positive pressure condition is equipped with foldable safe pathway system. Numerical analyses of temperature and pressure distribution with distance from fire source were performed considering fire scenario of new train vehicle. The smoke temperatures did not exceed $200^{\circ}C$ that distance from the fire source was more than 20 m and smoke pressure was reduced with distance from fire source. Maximum smoke pressure was 14 Pa and average pressure was 6 Pa in position of prevention smoke screen. As results, to install foldable safe pathway system, ventilation system is need to maintain 6 Pa positive pressure condition.

Muti-Path Search Algorithm for Safe Movement of Swarm of Unmanned Systems (군집 무인체계의 안전한 이동을 위한 다중 경로 탐색 기법)

  • Lee, Jong-Kwan;Lee, Minwoo
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.25 no.1
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    • pp.160-163
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    • 2021
  • In this paper, we present a path search scheme for the safe movement of the swarm of unmanned systems in unknown dangerous areas. Some of the swarm searches for the primary and secondary paths before the majority of swarm move through dangerous areas. In terms of rapid movement from the dangerous area and preparation for an accident, the primary path is searched first in the destination's direction. The secondary path is searched by considering the distance between the paths to guarantee a safe distance. The computer simulations show that the proposed scheme is suitable for the swarm of unmanned systems.

Adaptive Cruise Control of EV using Sliding Mode Controller (슬라이딩 모드 제어기를 이용한 EV의 차량 간격 자동 제어)

  • Lim, Hui-Seong;Shin, Soo-Cheol;Park, Sang-Hoon;Lee, Taeck-Kie;Kim, Young-Real;Won, Chung-Yuen
    • Proceedings of the KIPE Conference
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    • 2010.11a
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    • pp.312-313
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    • 2010
  • In this paper, the ACC(Adaptive Cruise Control) method of Electric Vehicle using sliding mode controller is proposed. The IPMSM is safely controlled as safe distance using distance sensor at front of vehicle. The speed of EV is controlled to ensure safe distance using sliding mode controller. The sliding mode controller is suitable to apply nonlinear system like EV. In this paper, IPMSM speed control ability is verified by simulation using PSIM.

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A Study on a Collision Case Under Dense Fog Dealt in the English Court (영국법원의 판결에 나타난 무중에서의 구체적인 항법 - Maloja II사건(영국항소원 1993.12.1) -)

  • 김인현
    • Journal of the Korean Institute of Navigation
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    • v.22 no.3
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    • pp.93-102
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    • 1998
  • This article aims at suggesting a practicla auide to navigation under restricted visibility by a study of an English court. This case os a good example of setting out safe speed. close-quarters situation, safe passing distance as the above factors are not enumerated in Collision Regulations.

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Predicting the Permanent Safe Donor Area for Hair Transplantation in Koreans with Male Pattern Baldness according to the Position of the Parietal Whorl

  • Park, Jae Hyun;Na, Young Cheon;Moh, Jae Seong;Lee, Seung Yong;You, Seung Hyun
    • Archives of Plastic Surgery
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    • v.41 no.3
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    • pp.277-284
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    • 2014
  • Background The most crucial factor in hair transplantation for male pattern baldness (MPB) patients is the efficient utilization of the donor-recipient ratio. However, there is no known factor that scientifically predicts the rate of progression of alopecia or indicates a permanently safe donor area. Methods The study considered 1,008 Korean adult males with MPB; of these, it excluded 56 males with an absence of parietal whorls (PWs). The authors investigated the distance from the vertical bimeatal line (VM) to the PW, from the PW to the upper border of the helical rim (HR), and the distance from the PW to the occipital fringe (OF) in 952 subjects with a PW. Furthermore, we examined the distance from the PW to the OF considering the duration of alopecia and age in 322 subjects with vertex alopecia. Results The distance between the VM and PW varied from 1.5 to 11 cm, with an average distance of 6.25 cm. The PW-HR distance ranged from 3.4 to 17.5 cm, and the average distance was 7.79 cm. The PW-OF distance ranged from 0.5 to 5.5 cm, and the average distance was 2.37 cm. Conclusions For the PW, very large variations existed in the vertical direction. The position of the PW could predict the progression range of the total alopecia of the vertex. Alopecia mostly progresses within 6 cm of the PW toward the occipital side.

Performance Analysis of Landing Point Designation Technique Based on Relative Distance to Hazard for Lunar Lander (달 착륙선의 위험 상대거리 기반 착륙지 선정기법 성능 분석)

  • Lee, Choong-Min;Park, Young-Bum;Park, Chan-Gook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.1
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    • pp.12-22
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    • 2016
  • Lidar-based hazard avoidance landing system for lunar lander calculates hazard cost with respect to the desired local landing area in order to identify hazard and designate safe landing point where the cost is minimum basically using slope and roughness of the landing area. In this case, if the parameters are only considered, chosen landing target can be designated near hazard threatening the lander. In order to solve this problem and select optimal safe landing point, hazard cost based on relative distance to hazard should not be considered as well as cost based on terrain parameters. In this paper, the effect of hazard cost based on relative distance to hazard on safe landing performance was analyzed and it was confirmed that landing site designation with two relative distances to hazard results in the best safe landing performance by an experiment using three-dimensional depth camera.

A Study about the interactions of vessels running parallely in proximity to one another and safe conducting of them in restricted waterways (제한수역에서 근접 항해하는 선박의 상호작용과 안전항해거리에 관한 연구)

  • Lee Chun-Ki
    • Journal of Navigation and Port Research
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    • v.29 no.8 s.104
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    • pp.647-652
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    • 2005
  • When a vessel passes near a channel boundary, the boundary creates forces and moments acting on the vessel. With the same reason passing of two vessels closely gives same effects to each other. The principal difference between the above two cases is that the channel boundary is long and constant shape compared to those of vessels. The interaction forces and moments between two vessels could be assumed to be functions of the longitudinal distance $chi_0$, transverse distance $y_0$ and speeds of the two vessels. Passage of one vessel close to another is important operationally from the viewpoint of replenishment at sea, avoidance of collisions and passage of two vessels in restricted channels. The authors studied the interactions between two vessels running closely and calculated safe conducting distances according to separated distances and speeds of the two vessels.