• 한국측량학회지
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• 제31권6_2호
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• pp.529-538
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• 2013

Coastline is the most dynamic part of seascape since its shape is affected by various factors. Coastal zone is an area with immense geological, geomorphological and ecological interest. Monitoring coastal change is very important for safe navigation, coastal resource management. This paper shows a result of monitoring coastal morphological changes using Remote Sensing and GIS. Study was carried out to obtain intensity of erosion, deposition and sand bar movement in the Red River Delta. Satellite images of ALOS/AVNIR-2 and Landsat were used for the monitoring of coastal morphological changes over the period of 1975 to 2009. Band rationing and threshold technique was used for the coastline extraction. Tidal levels at the time of image acquisition varied from -0.89m to 2.87m. Therefore, coastline from another image at a different tidal level in the same year was considered to get the corrected coastline by interpolation technique. A series of points were generated along the coastal line from 1975 image and were established as reference points to see the change in later periods. The changes were measured in Euclidean distances from these reference points. Positive values represented deposition to the sea and negative values are erosion. The result showed that the Red river delta area expanded to the sea 3500m in Red river mouth, and 2873m in Thai Binh river mouth from 1975 to 2009. The erosion process occurred continuously from 1975 up to now with the average magnitude 23.77m/year from 1975 to 1989 and 7.85m/year from 2001 to 2009 in Giao Thuy area. From 1975 to 2009, total 1095.2ha of settlement area was eroded by sea. On the other hand, land expanded to the sea in 4786.24ha of mangrove and 1673.98ha of aquaculture.

• IEIE Transactions on Smart Processing and Computing
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• 제5권3호
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• pp.193-198
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• 2016

Lane change is an important issue in microscopic traffic flow simulations and active safety. Overtaking and changing lanes are dangerous driving maneuvers. This approach presents a lane-changing system based on speed and a minimum gap between vehicles in a vehicular ad hoc network (VANET). This paper proposes a solution to ensure the safety of drivers while changing lanes on highways. Efficient routing protocols could play a crucial role in VANET applications, safeguarding both drivers and passengers, and thus, maintaining a safe on-road environment. This paper focuses on the development of an intelligent transportation system that provides timely, reliable information to drivers and the concerned authorities. A test bed is created for the techniques used in the proposed system, where analysis takes place in an on-board embedded system designed for vehicle navigation. The designed system was tested on a four-lane road in Neemrana, India. Successful simulations were conducted with real-time network parameters to maximize quality of service and performance using Simulation of Urban Mobility and Network Simulator 2 (NS-2). The system implementation, together with the findings, is presented in this paper. Illustrating the approach are results from simulation using NS-2.

• 수산해양교육연구
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• 제12권2호
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• pp.199-212
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• 2000

It is very important to investigate the hull response of a fishing vessel in the sea to ensure the safe navigation and fishing operation in rough sea by preserving excellent sea keeping qualities. For this purpose, the author measured various responses of three stem trawlers in waves using real sea experimental measuring system. The author analyzed the experimental data using the statistical and spectral analyzing method to get the characteristics of the motion responses of the vessels according to the wave height and the ship's speed. The results obtained can be summarized as follows ; (1) Rather higher response of the pitch motion due to the wave height appeared in the head sea and the bow sea than any other wave direction without relevance to ship's size. In case of the roll motion, the beam sea and the quartering sea have a high response value. The period of peak of the pitch motion and the roll motion according to the wave height in each vessel has almost same value respectively. (2) The change of response of the pitch motions deeply depend on the ship's speed in the head sea and the bow sea, but not in the other wave direction. (3) The change of response of the roll motions in the beam sea, the quartering sea and the following sea are affected by the influence of the ship's speed in 5k't to 8k't, but not related to the ship's speed in out of that range.

• 대한인간공학회지
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• 제36권1호
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• pp.37-52
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• 2017

Objective: The present study developed a user-centered 3D virtual liver surgery planning (VLSP) system called Dr. Liver to provide preoperative information for safe and rational surgery. Background: Preoperative 3D VLSP is needed for patients' safety in liver surgery. Existing systems either do not provide functions specialized for liver surgery planning or do not provide functions for cross-check of the accuracy of analysis results. Method: Use scenarios of Dr. Liver were developed through literature review, benchmarking, and interviews with surgeons. User interfaces of Dr. Liver with various user-friendly features (e.g., context-sensitive hotkey menu and 3D view navigation box) was designed. Novel image processing algorithms (e.g., hybrid semi-automatic algorithm for liver extraction and customized region growing algorithm for vessel extraction) were developed for accurate and efficient liver surgery planning. Usability problems of a preliminary version of Dr. Liver were identified by surgeons and system developers and then design changes were made to resolve the identified usability problems. Results: A usability testing showed that the revised version of Dr. Liver achieved a high level of satisfaction ($6.1{\pm}0.8$ out of 7) and an acceptable time efficiency ($26.7{\pm}0.9 min$) in liver surgery planning. Conclusion: Involvement of usability testing in system development process from the beginning is useful to identify potential usability problems to improve for shortening system development period and cost. Application: The development and evaluation process of Dr. Liver in this study can be referred in designing a user-centered system.

• 해양환경안전학회지
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• 제15권3호
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• pp.223-228
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• 2009

2003년 태풍 매미로 인하여 안전한 피항지로 여겨졌던 진해만에서도 강풍에 의한 주묘로 좌초, 충돌 등 많은 해양사고가 발생하였다. 투묘에 대한 사항이나 주묘를 예측하기 위해서는 외력과 대항력에 대한 비교 검토가 필요하다. 하지만 풍압력에 대한 부분에서 스윙현상으로 인한 풍압면적 적용에 대한 연구가 진행되고 있으나, 여전히 논란의 대상이 되고 있다. 따라서 실습선 한바다호를 대상으로 선체에 작용하는 외력과 외력에 대한 대항력을 수치적으로 계산하고, 이를 실제로 주묘가 발생했던 실선계측자료와 상호 비교 분석함으로써 묘박 중선박에 가해지는 풍압력에 대한 평가를 실시하였다.

• 수산해양기술연구
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• 제53권2호
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• pp.187-195
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• 2017

We have studied the efficient operation of the radar and the appropriateness of the installation location, when constructing the VTS system. As the Civil-Military Complex Harbour (Kangjeong Port) is completed in 2016, we set the control area within 10 nautical miles centering on Kangjeong Port, and found out and removed the operational radar blind area of VTS system to provide safe navigation information for vessels that navigating this area. Assuming that two international cruise ships entering at the same time, we performed the radar simulation and compared the images by considering the three sites of Kangjeong Port, Miaksan and Seoguipo Port. Simulation results for a single radar installed at Kangjung Port indicate that the blind area was largely affected by two large cruise ships and the surrounding islands. The blind area due to Kogunsan was considerably large when installed in Miaksan, but the blind area due to the influences of Beomseom, Moonseom and Seopseom was negligibly large. It seems that additional radar installation is necessary as a complementary solution to solve this blind area. When two radars were installed at Miaksan and Kangjeong Port, the residual blind area due to the Seopseom was $0.25km^2$ at 0.1~0.33 nautical miles in the southeast direction from Seopseom. In addition, the remaining blind area with two cruise ships mutually influenced was $0.18km^2$, which did not occur with a single cruise ship.

• Journal of Advanced Marine Engineering and Technology
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• 제35권4호
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• pp.491-499
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• 2011

1999년부터 운영이 시작된 팔미도, 어청도 DGPS 해상 기준국을 시작으로 우리나라에서는 총 17개의 DGNSS 기준국을 운영하고 있는 명실상부한 DGNSS 운영 인프라의 강국이 되었다. 본 논문은 DGPS 해양 기지국을 근간으로 사용하여 우리나라의 대표적인 정기여객선 항로 구간인 제주에서 인천, 부산에서 제주, 제주에서 녹동 구간의 300 kHz 주파수의 해상 및 육상에서의 전파특성을 측정하여, 해안 DPGS 기준국에서 서비스 범위를 조사함으로써, 우리나라 DGNSS 서비스 영역을 측정하였다. 서 남해안의 선박 항로구간의 DGPS 서비스 도달범위를 확인해 본 결과 우수한 품질의 전파신호가 100 NM(권장서비스 범위) 이상 도달됨을 확인하였다. 또한 이를 통하여 선박 안전항행 및 다양한 해양안전시설물에 대하여 위치보정정보의 활용과 향후 DGPS 해양 기준국 확장에 유용할 것으로 판단된다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2003년도 추계학술발표회
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• pp.7-11
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• 2003

선박충돌사고는 많은 원인이 서로 복잡하게 상호작용을 하여 발생하고 있으며, 특히 인적요인에 의한 충돌사고가 가장 큰 비중을 차지하고 있다. 이러한 선박충돌사고 원인분석은 선박의 안전 운항상의 측면에서 매우 중요하다고 할 수 있다. 따라서 본 연구의 목적은 시스템다이내믹스법을 이용하여 선박충돌사고 인적요인 모델을 구축하고, 선박충돌사고를 감소시키기 위한 가장 효과적인 대책을 수립하기 위한 정책요소론 제시하고자 한다. 본 연구의 수행을 위해 ]nM법에 의한 충돌사고원인의 구조분석을 인과지도상의 정량적, 정성적, 피드백 루프로 변환하였다. 그리고 표준시뮬레이션모델과 8가지 정책시뮬레이션모델을 20년간(1993-2012) 시뮬레이션을 수행하였다.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2004년도 춘계학술발표회
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• pp.29-34
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• 2004

해양사고는 많은 원인이 서로 복잡하게 상호작용을 하여 발생하고 있다. 이러한 해양사고의 분석은 선박의 안전 운항상의측면에서 매우 중요하다고 할 수 있다. 따라서 본 연구의 목적은 시스템다이내믹스법을 이용하여 해양사고 원인과 개선책에 대한 모델을 구축하고, 요소의 개선에 대한 효과를 분석하고자 한다. 본 연구의 수행을 위해 해양사고 원인과 개선책의 요소를 브레인스토밍법에 의해 추출하고, 인과지도상의 정량적, 정성적, 피드백루프로 변환하였다. 그리고 표준모델과 4가지 정책모델에 대해 23년간($1997\~2020$) 시뮬레이션을 수행하였다.

• 한국정보통신학회논문지
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• 제20권3호
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• pp.519-526
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• 2016

해양사고가 빈번히 발생함에 따라 해상교통관제를 통해 항해의 안전성과 효율성을 개선하기 위한 해상 트래픽 모니터링 시스템을 구축할 필요성이 대두되고 있다. 이와 같은 목적을 위해, 최근에 X-대역 해양 레이더는 해수면 정보를 수집하는데 사용하고 있는데, 파랑 정보를 정확하게 측정하여 해상교통관제 영역 내에서 선박의 안전하고 효율적인 움직임을 제공하는 것이 요구된다. 본 논문에서는 세 가지의 다른 해류 속도를 산출하는 방법 즉, 최소자승법을 이용한 방법, 해류 속도를 반복 최소자승 갱신 방법, 가변적인 해류 속도의 정규화된 스칼라 곱을 극대화하여 해류 속도 추정치를 제공하는 방법 등에 대해 부이 데이터와 비교하고, 그런 후에 반복 갱신 방법을 수정하여 초기의 해류 속도를 개선하여 효과적으로 파랑 정보를 예측하도록 설계된다. 다수의 실험을 통하여 제안한 방법은 기존 방식에 비해 파랑 정보를 효과적으로 추출할 수 있음을 보인다.