• International Journal of Highway Engineering
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• v.9 no.3
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• pp.29-38
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• 2007

This study investigated the effects of delineation systems on drivers' maneuver and how the effectiveness of delineation system can be further improved according to the road geometry. The experiments were conducted to collect lateral placement data and detection distance data using GPS equipped vehicles. The main results are summarizedas follows. Firstly, installing the delineation facilities on the roads helps drivers to recognize road alignment. Secondly, the detection distance is longer for delineators than for raised pavement marker in tangent section, while there is no difference in curve section. The chevron show the longest detection distance in the curve section, while the raised pavement markers showed no distinctive performance in terms of detection distance and lateral placement. Therefore, we can recommend install delineators in the tangent sections and chevrons in curve sections, based on the analysis results of effects of delineation facilities.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.297-306
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• 2022

AtoN is an acronym for aids to navigation that indicate the position or direction of navigable areas and obstructions. AtoN should be arranged in consideration of unfamiliar navigator's convenience when it is indicated as the limits of navigable areas. Several narrow channels exist on the SW coast of Korea owing to the geographical effect, and the lateral or cardinal marks by the IALA maritime buoyage system are arranged along the narrow channels. This is an actual case study that analyzed the AtoN's role for safety navigation after changes in the maritime traffic environment owing to aquarfarm's development on narrow channels in the Korean SW coast. The analysis results of 5 narrow channels indicated that certain marks did not function properly as lateral or cardinal marks owing to the aquarfarm's location on navigable areas. Therefore, the following were suggested to improve AtoN on narrow channels: changing the position of marks, installing aquafarm's marks, and expressing the aquafarm's position on the nautical chart.

• Journal of the Korean Institute of Navigation
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• v.25 no.2
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• pp.107-118
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• 2001

This paper describes prototype Aids to Navigation Simulation System (AtoNSiS) that we have recently developed Aids to Navigation (AtoN) training equipment based on the virtual reality technology. To produce an enhanced AtoN simulation experience, three-dimensional (3D) cardinal and lateral buoys are created, and then build up the virtual 3D waterway world according to the guidelines of IALA (International Association of Lighthouse Authorities) in region B. The AtoNSiS have Simulation Module (SM) and Explanatory Module (EM). SM is to learn about the IALA-B system using virtual navigation world varying with environmental factors. EM is to view more detailed marker characteristics using 3D objects. In this work, we present system design concepts, development processes, and simulation experiments of prototype AtoNSiS. Results from tests and evaluations with five subjects provide practical insight on the importance of AtoNSiS.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.5
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• pp.417-422
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• 2016

Aids to Navigation (AtoN) are marine traffic facilities to improve the safety and efficiency of shipping. "New Dangers" should be appropriately marked using lateral, cardinal or isolated danger marks or by using an Emergency Wreck Marking Buoy. However, Emergency Wreck Marking Buoys are difficult to implement in terms of speed and accuracy of installation. In the case of sinking accidents, it is often difficult to immediately install an Emergency Wreck Marking Buoy because of weather conditions, the marine environment or accident positioning. This study concerns Auto-Releasing Emergency Wreck Marking Buoys, which should be installed in all vessel for safe marine navigation and efficient maritime transport with reference to the Maritime Buoyage System (MBS). Auto-Releasing Emergency Wreck Marking Buoys include an auto-release unit, auto reel chain and auto lighting lantern. These buoys can be automatically released from the deck of a vessel and will float in the water for quick installation at the scene of an accident, even in the case of sinking accidents. Auto-Releasing New Mark Buoys are expected to reduce to installation process, prevent secondary accidents by the risk of navigation and be search and rescue rapidly.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2016.05a
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• pp.20-21
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• 2016

Aids to Navigation (AtoN) is marine traffic safety facility to facilitate the safe and efficient movement of shipping and enhance the protection of the marine environment by the regulation or guideline of The International Association of Marine Aids to Navigation and Lighthouse Authorities (IALA). By IALA NAVGUIDE, the term "New Danger" is defined as newly discovered hazards not yet shown in nautical documents and includes naturally occurring obstructions such as sandbanks or rocks or man-made dangers such as wrecks. 'New Dangers' should be appropriately marked using Lateral, Cardinal, Isolated Danger marks or by using the Emergency Wreck Marking Buoy. However, the Emergency Wreck Marking Buoy has difficulties with implementation conditions in terms of speed and accuracy to install the buoy. In case of sinking accidents, it is difficult immediately to install the Emergency Wreck Marking Buoy because of weather conditions, marine environments and accident position. This paper studies Auto Releasing New Danger Mark Buoy on the deck which can be automatically to release from the deck of a vessel and float in the water and quickly install the accident position in case of sinking accidents. The buoy will be to reduce the risk of navigation and prevent secondary collisions.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.263-265
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• 2011

우리나라 해역에서 선박의 대형화, 고속화와 선박교통량의 증가 및 항만과 해양개발 등으로 해상교통 환경은 급속하게 변화하고 있으며, 항로의 좌 우 측방 한계 표시, 항행위해요소의 표시 등의 용도로 사용되는 부표류는 항만, 연안해역 및 내륙수로에서 통항 선박의 안전을 위하여 그 수요가 점진적으로 늘어나고 있다. 변화하는 해양교통 환경에 능동적으로 대처하고 부표관리 업무의 효율성을 증대하기 위하여 경량화, 내부식성, 저비용 등 장점으로 정온도가 유지되는 항내나 내륙수로 등에서 국제적으로 항로표지용 부표로 이용되고 있는 플라스틱 부표의 국외 개발 동향, 제조 방법 및 시제품의 특성 평가를 통한 기술 향상 방안에 대하여 기술하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.07a
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• pp.15-17
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• 2015

입출항 선박의 증가와 선박의 대형화로 인하여 두 선박간의 항법규정을 기본으로 하는 해상충돌예방규칙 등 기존의 규정만으로는 연안해역과 항만의 출입항로에서 안전하고 원활한 해상교통을 기대하기 어렵게 되었다. 낚시 유어선과 항내운항선박 등 혼잡요인이 많은 항만의 항로환경을 해상교통공학적인 방법으로 연구하여 출입항 선박들의 혼잡을 감소하고 어선 및 어장의 간섭을 줄일 수 있는 시스템을 마련하여야 한다. 항로와 정박지, 교통안전특정해역, 항행보조시설 등 하드웨어 개선뿐만 아니라 소프트웨어라고 할 수 있는 도선사 승하선 구간의 해도표시, 출입항 선박간의 방향별 집단관리로 등으로 혼잡을 정리하는 개선이 필요하다. 항로의 혼잡과 위해요소의 감소 및 어민 등 항로주변 수역 이해관계의 조율에 기여할 수 있는 이러한 연구가 현실에 부합하기 위해서는 현장에서 항로를 이용하는 전문가의 축적된 경험을 바탕으로 연구함이 효과적이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.385-386
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• 2013

우리나라 해역에서 선박의 대형화, 고속화와 선박교통량의 증가 및 항만과 해양개발 등으로 해상교통 환경은 급속하게 변화하고 있으며, 항로의 좌 우 측방 한계 표시, 항행위해요소의 표시 등의 용도로 사용되는 등 명기는 항만, 연안해역 및 내륙수로에서 통항 선박의 안전을 위하여 그 수요가 점진적으로 늘어나고 있다. 항로표지에 사용하는 등명기의 정기검사는 항로표지법 제31조 및 "항로표지용장비 용품검사기준(해양수산부고시 제2013-101호, 2013.5.8)"에 따라 3년 주기로 수검하여 합격품에 한하여 사용토록 규정하고 있다. 등명기의 정기검사 유효기간에 대한 검증을 위하여 설치장소, 해상여건 등을 고려한 현장시험을 통하여 등명기의 사용 기간에 따른 열화 특성을 조사하고 적정 정기검사주기 및 교체 주기에 대한 분석의 필요성이 대두되고 있는 실정이다. 본 연구에서는 LED 등 명기의 실제 사용 환경에서 사용 경과 시간에 따른 광학적 특성, 전기적 특성 및 외관상태 등을 조사하고 분석하여 사용시간 경과에 따른 LED 등명기의 특성 변화에 대하여 기술하였다.

• Radiation Oncology Journal
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• v.20 no.4
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• pp.396-404
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• 2002

Purpose : Many papers support a correlation between rectal complications and rectal doses in uterine cervical cancer patients treated with radical radiotherapy. In vivo dosimetry in the rectum following the ICRU report 38 contributes to the quality assurance in HDR brachytherapy, especially in minimizing side effects. This study compares the rectal doses calculated in the radiation treatment planning system to that measured with a silicon diode the in vivo dosimetry system. Methods : Nine patients, with a uterine cervical carcinoma, treated with Iridium-192 high dose rate brachytherapy between June 2001 and Feb. 2002, were retrospectively analysed. Six to eight-fractions of high dose rate (HDR)-intracavitary radiotherapy (ICR) were delivered two times per week, with a total dose of $28\~32\;Gy$ to point A. In 44 applications, to the 9 patients, the measured rectal doses were analyzed and compared with the calculated rectal doses using the radiation treatment planning system. Using graphic approximation methods, in conjunction with localization radiographs, the expected dose values at the detector points of an intrarectal semiconductor dosimeter, were calculated. Results : There were significant differences between the calculated rectal doses, based on the simulation radiographs, and the calculated rectal doses, based on the radiographs in each fraction of the HDR ICR. Also, there were significant differences between the calculated and measured rectal doses based on the in-vivo diode dosimetry system. The rectal reference point on the anteroposterior line drawn through the lower end of the uterine sources, according to ICRU 38 report, received the maximum rectal doses in only 2 out of the nine patients $(22.2\%)$. Conclusion : In HDR ICR planning for conical cancer, optimization of the dose to the rectum by the computer-assisted planning system, using radiographs in simulation, is improper. This study showed that in vivo rectal dosimetry, using a diode detector during the HDR ICR, could have a useful role in quality control for HDR brachytherapy in cervical carcinomas. The importance of individual dosimeters for each HDR ICR is clear. In some departments that do not have the in vivo dosimetry system, the radiation oncologist has to find, from lateral fluoroscopic findings, the location of the rectal marker before each fractionated HDR brachytherapy, which is a necessary and important step of HDR brachytherapy for cervical cancer.

• Radiation Oncology Journal
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• v.16 no.1
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• pp.63-69
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• 1998

Purpose : This study is to evaluate the efficacy of small bowel displacement system(SBDS) in post-operative pelvic radiation therapy(RT) of rectal cancer patients by measurement of small bowel volume included in the radiation fields receiving therapeutic dose. Materials and Method : Ten consecutive new rectal cancer patients referred to the department of Radiation Oncology of Samsung Medical Center in May of 1997 were included in this study. All patients were asked to drink $Castrographin^(R)$ before simulation and were laid prone for conventional simulation and CT scans with and without SBDS. The volume of opacified small bowel on CT scans, which was to be included in the radiation fields receiving therapeutic dose, was measured using Picture archiving and communication system (PACS). Results : The average small bowel volumes with and without SBDS were 176.0ml(5.2-415.6ml) and 185.1ml(54.5-434.2ml), respectively The changes of small bowel volume with SBDS compared to those without SBDS were more than $10\%$ decrease in three, less than 10% decrease in two, less than $10\%$ increase in three, and more than $10\%$ increase in two patients. Conclusion : No significant advantage of using SBDS in post-operative pelvic RT for rectal cancer patients has been shown by small bowel volume measurement using CT scan considering additional effort and time needed for simulation and treatment setup.