• Progress in Medical Physics
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• v.16 no.1
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• pp.10-15
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• 2005

IAEA's guidance levels have been provided for western people to the end. Guidance levels lower than the IAEA'S will be necessary in view of Korean people's proportions. Therefore, we need to develope the standard doses for Korean people. And we conducted a nationwide survey of patient dose from x-ray examinations in Korea. In this study, the 278 institutions were selected from Members Book of Korean Hospital Association. The valid response rate was approximately 57.9%. Doses were calculated from the questionnaires by NDD method. We obtained the results were as follows; 1) General radiographic equipments were distributed for 42.0%, fluoroscopic equipments 29.4%, dental equipments 13.2%, CT units 8.1 % and mamographic units 7.2%. 2) According to classification by rectification, three-phase equipments were 29.9%, inverter-type generators 29.5%, single-phase equipments 25.5%, constant voltage units 9.0% and unknown units 6.0%. 3) According to classification by receptor system, film-screen types were 46.8%, CR types 26.8%, DR types 17.7% and unknown types 8.9%. 4) The number of examinations were chest 49.2%, spine 16.8% and abdomen 12.7%. 5) Patient doses were head AP 3.44 mGy, abdomen AP 4.25 mGy and chest PA 0.39 mGy.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.83-90
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• 2022

About 90.5 % of barge-towing tugs weigh less than 200 gross tonnage and most are served by the master alone. They are also not subject to the regulations on the working hours and manning levels stipulated in the Seafarers' Act. Therefore, the master of barge-towing tugs cannot take sufficient rest during the navigational watch. Moreover, barge-towing tugs do not satisfy the human seaworthiness due to the inevitable performance of the navigational watch which must be alternately undertaken with an unqualified person, called the "Boatswain". Furthermore, there are many cases in which the master or owner of a tug fails to comply with the additionally required minimum manning levels stipulated in the Ship Of icers' Act when a tug tows a barge. This study reviews the following: (1) the regulations on the working hours and manning levels that are stipulated in the Seafarers' Act, (2) the regulations on the minimum manning levels for ship of icers of the tug's deck part that are stipulated in the Ship officers' Act, (3) marine accidents in the barge-towing tugs. As a result I suggested that one additional deck officer should be on board when a tug tows a barge through the revision of the minimum manning level for ship of icer on the deck part in order to prevent marine accidents of tugs effectively. Especially, the Act on the Punishment, etc. of the Serious Accident came into effect on January 27, 2022. If marine casualties occur continuously at sea due by the same cause, and the cause of such marine casualties would be turned out by the fatigue of the ship of icer caused by insufficient institutional arrangements, the administrator of competent Authorities of Maritime and Port could be punished, so it seems to prepare for it.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.1
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• pp.1-9
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• 2018

All ships should ensure stability in accordance with IMO regulations. However, GM is only used to determine ship stability because it takes a lot of time to validate all regulations. This is a problem given that the safety of vessels cannot be guaranteed, potentially leading to accidents. There is a need for a more intuitive and comprehensive method of confirming the stability of ships. This study developed a stability index that expresses ship stability in one value. An index equation is defined based on the 6 stability criteria for ships prescribed by IMO and the result of calculating the ship stability of a model ship. A stability index has been derived for each loading condition by applying the index equation to the same ship. It can clearly be seen that this stability index appropriately explains the criteria. In other words, it is possible to assess ship stability with one value and confirm whether the ship stability satisfies IMO regulations. This index will help masters and officers more easily and accurately check ship stability.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.3
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• pp.251-261
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• 2000

This paper deals with the precision analysis of GPS measurement referred to ITRF96 which is the new reference frame announced in 1996, and show the data processing results of short and long baselines with different methods. In this paper, we minimized the observation error of GPS using precise ephemerides which has provided by Jet Propulsion Laboratory and represents the comparative analysis results of baseline measurements using GIPSY-OASIS II software. Here, we also discussed the accuracy of data processing methods.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.11a
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• pp.61-70
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• 2004

This paper treats optimal route assessment system at seaway based on weather forecasting and wave measurement through observation. Since early times. captain & officer have been sailing to select the optimum route considering the weather ana ship status condition empirically. However. it is rare to find digitalized onboard route support system whereas weather fax or wave and swell chart are utilized for the officer. based on officer's experience. In this paper, optimal route assessment system which is composed of voyage efficiency and safety component is introduced. Optimum route minimized ETA (estimated time of arrival) ana fuel consumption is evaluated for efficient voyage considering speed loss and power increase based on wave added resistance of ship. In the view point of safety, seakeeping prediction is performed based on 3 dimensional panel method. Basically. the weather forecast is assumed to be prepared previously in order to operate this system.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.833-841
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• 2004

This paper treats optimal route assessment system at seaway based on weather forecasting and wave measurement through observation Since early times, captain & officer have been sailing to select the optimum route considering the weather and ship status condition empirically. However, it is rare to find digitalized onboard route support system whereas weather fax or wave and swell chart are utilized for the officer, based on officer's experience. In this paper, optimal route assessment system which is composed of voyage efficiency and safety component is introduced. Optimum route minimized ETA(estimated time of arrival) and fuel consumption is evaluated for efficient voyage considering speed loss and power increase based on wave added resistance of ship. In the view point of safety, seakeeping prediction is performed based on 3 dimensional panel method. Basically, the weather forecast is assumed to be prepared previously in order to operate this system.

• Proceedings of the Korea Water Resources Association Conference
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• 2005.05b
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• pp.850-854
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• 2005

본 연구에서는 홍수가 발생할 경우 그 피해에 대한 잠재위험도를 산정하는 방법론을 제시하고자 한다. 이를 위하여 대상유역의 연간 홍수피해 잠재위험도의 기대치를 나타내는 홍수피해 잠재위험 기대치(Expected Potential Risks of Flood Damage, EPR)라는 새로운 개념을 정의하고 이 개념을 이용해 잠재위험도를 산정하도록 한다. 우선 EPR을 선장하기 위한 요소로 대상유역의 노출성(E)과 취약성(V)을 정의하고, 빈도-유량 곡선, 수위-유량 곡선, 수위-노출성$\cdot$취약성 곡선, 빈도-노출성$\cdot$취약성 곡선을 정의하도록 한다. 빈도-유량 곡선은 대상유역의 하천정비기본계획 자료와 실측자료를 이용해 산정하고,, 수위-유량 곡선은 HEC-G대RAS 모형을 이용하여 산정하였다. 대상유역은 경기도 용인시에 위치한 금학천 유역으로, 산정결과는 최대 노출성 및 취약성 지수를 각각 100으로 볼 때, 노출성 지수는 28, 취약성 지수는 32.25이고, 50년 빈도 홍수피해 잠재위험도는 30.13로 산정되었다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.41-43
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• 2012

E-Navigation 아키텍쳐 상세화 과정에서 이용자 요구사항은 안전항해 기능정의 레벨과 사용자 요구서비스 상세화 레벨로 나누어 입력된다. 본 연구는 연안해역에서 선박안전 항해를 지원하기 위하여 필요한 기본정보 및 서비스 레벨에서 정보를 도출하는데 목적이 있다. 도선사, 선장 및 VTS 운영자, 해양경찰청에 근무하는 항해경험이 풍부한 전문가를 대상으로 설문을 행하고 그 결과는 해양기상 및 해상상태 정보, 상황인식 및 충돌방지를 위한 정보로 나누어 정리하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.06a
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• pp.585-587
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• 2012

관제구역에서 선박들이 서로 조우할 때, 관제사 입장에서는 서로 안전하게 통과할 수 있다고 생각되는 조우관계가 불과 몇 초, 몇 분 뒤 전혀 예상치 못한 상황으로 발전하는 경우가 많이 발생한다. 이러한 상황은 관제사와 선박의 항해사들의 관점과 상황에 대한 해석이 상이하여 의사결정과정의 불일치가 발생하기 때문이다. 본 연구에서는 관제사과 모니터링하고 있는 VTS image를 실시간으로 선박과 공유할 수 있는 방법을 제시함으로써 위와 같은 문제점을 해결함은 물론 상황이해에 대한 불일치로 인해 발생하는 불필요한 교신을 줄여서 해상교통안전에 기여하고자 하였다. 최근 항공분야 및 도로교통분야에서 스마트폰을 이용하여 정보를 제공함으로써 많은 성과를 올리고 있는 점에 착안하여 VTS 어플리케이션을 개발하여 실시간 VTS image를 선장, 항해사에게 제공할 수 있는 방안을 제시하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.186-188
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• 2016

전자항법시대의 도래로, 항해사의 의사결정시 항해설비 의존도는 점차 증가하고 있으며, 국제협약에 의해 ECDIS(전자해도 정보시스템)의 강제화로 전자항해설비 사용을 위한 친숙화는 필수적이다. 국제사회에서도 항해사 및 도선사들이 항해설비의 친숙한 사용을 도모하기 위한 표준이 필요함을 인식하고, 2015년 6월 IMO MSC 95차에서 항해설비에 표준모드 적용을 위한 S-Mode 가이드라인 개발이 2019년까지의 e-Navigation 주요개발 과제로 승인되었다. S-Mode는 주요 사용자인 항해사, 선장 및 도선사에게 표준화된 화면, 기능 제공을 통해 친숙한 업무환경을 통해 상황인식에 기여함으로써 항해안전성을 향상시키고, 교육 훈련 측면에서의 선원의 부담을 경감시키기 위한 목적으로 개발 예정이다. S-Mode 가이드라인 개발을 위해서, HCD(인간중심적 설계)에 기반 하여, 항해설비에 대한 인적측면에서의 개선이 이루어질 것으로 예상된다. 본 연구에서는 ECDIS를 활용하여 S-Mode 가이드라인 개발을 위한 주요 방안 및 항해화면의 개선방안을 연구하였다.