• Journal of Navigation and Port Research
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• v.26 no.2
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• pp.161-166
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• 2002

In view of the great disparity between forecasts of Shanghai port container handling capacity and its real results, we choose a dynamic forecast method by the causality model dynamic compensation to predict Shanghai port container handling capacity. And we forecast Shanghai port container handling capacity by using this method. We have made a satisfactory achievement, which provides a more reliable and practical way to forecast container handling capacity.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.124-127
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• 2017

선박에서 배출되는 환경오염 물질 및 온실가스에 대한 규제가 강화됨에 따라, 환경오염 물질 및 온실가스의 배출과 직접적으로 관련있는 연료 소모량을 줄이려는 다양한 연구가 진행되고 있다. 연료 소모량을 줄이기 위한 방안 중 하나는 환경 및 기상 예보를 이용하여 연료가 가장 적게 소모되는 항로를 찾는 것이다. 기존 연구에서는 연료 소모량을 주된 목적함수로 최소화 하되, 도착 시간에 대한 조건을 평가하기 위해 도착 시간의 기댓값을 계산하고 추가적인 목적함수로 고려하는 경우가 많았다. 그러나 선박 운항 예측 시 적용되는 환경 외란 정보는 상당한 불확실성을 포함하고, 이로 인해 발생하는 운항 속도 및 도착 시간에 대한 불확실성도 상당히 클 수 있기 때문에, 도착 시간의 기댓값뿐만 아니라 도착 시간에 대한 불확실성을 기반으로 제한 시간 내에 선박이 도착할 확률을 정량적으로 평가하는 것이 필요하다. 본 연구에서는 다목적 최적화 기법을 이용해 도착 시간의 기댓값과 연료 소모량에 대한 Pareto set을 구하되, 환경 외란으로부터 발생하는 도착 시간의 불확실성을 계산하여, 제한 시간 내에 선박이 도착할 확률을 계산하고 이를 항로 최적화 시 적용한다. 제안하는 방법의 유용성을 검증하기 위해 실제 환경에 가까운 맵을 기반으로 부산-도쿄 간의 항로를 최적화하고, 그 결과에 대해 논의한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.490-495
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• 2004

안목항의 방파제 확장 건설로 인하여 항남측에 심각한 침식현상이 광범위하게 발생하고 있는 데 이를 규명하기 위하여 현재 주변 해안선 변형 현상을 기초로 연안 표사 이동(littoral drift)도를 정성적으로 작성하였으며 수치 모형실험을 통하여 상세할 표사이동의 변화를 살펴보았다. 수치모형 실험은 파랑 변형 및 해빈류 예측 모형인 WADEM-P, DISEM-R로 수행되었다. 항 내 매몰 및 하천 폐색을 근본적으로 해결하면 해안선 침식문제를 완화 시 킬 수 있는 장치로서 모래운송장치(sand transfer)의 필요성이 언급되었으며 앞으로 연안 표사량이 많은 동해안에서의 항만 건설시 꼭 필요한 부대장치임을 강조한다. 또한 주기적인 연안관측 프로그램을 수립하여 연안 표사량 및 해안 침식율을 산정한 후 모래이송장치의 설치 여부 및 그 규모를 판단할 필요가 있다.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.293-293
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• 2019

최근 도심지 침수예방을 위해 구조적 비구조적인 대책 등이 수행되어 왔으나, 도심지의 국지성 호우의 발생빈도가 증가함에 따라 단시간의 도심지 침수예측의 중요성이 다시 대두되고 있다. 이에 도심지 침수 예측을 위해서는 수치모의 프로그램을 사용한 연구가 진행되어 왔으나, 국지성 호우에 의한 침수를 막을 만킁의 실시간 위험예측은 아직까지 힘든 실정이다. 한편 해양재난의 침수를 예방하기 위해서 국립재난안전연구원(2017)에서는 과학적 보간법을 적용한 침수예측 모형인 SIND(Scientific Interpolation for Natural Disaster) Model을 개발한 바 있다. 따라서 본 연구에서는 SIND Model을 도심지 침수예측에 적용하여 집중호우와 같은 단기간의 침수를 예방하고자 한다. SIND Model은 기 구축된 침수예상도를 활용하여 모든 시나리오에 대한 침수 위험도 등급을 실시간으로 평가하는 모형이다. 국토부에서 제공하는 국가홍수위험지도와 내수침수지도를 활용하였고, SIND Model은 Comsol Multyphisic를 활용하여 침수예측지도를 생성하였다. 기존에 해양재난 예측을 위해 사용하였던 Risk Grade 방정식에 시간 항(time term)과 도심지의 최초 침수 발생위치에 생성 항(source term)을 추가하여 도심지 침수특성을 반영하였다. 결과를 평가하기 위하여 CRITIC(CRiteria Importance Through Intercriteria Correlation) 방법을 활용한 형상유사도를 산출하였다. 그 결과, 기 구축된 홍수위험지도와 형상유사도는 전체 구역 중 80%의 구역이 0.8 이상의 값을 나타내었다. 20%의 구역에서는 복잡한 도심지의 건물, 구조물 등의 침수특성을 반영하지 못하여 형상유사도가 낮게 평가된 것으로 판단되며, 향후 위험도 예측을 위해 배수시스템 등의 영향인자를 고려한다면 위험도 등급 예측의 정확도를 높일 수 있을 것이라 기대된다.

• Journal of the Korean Geotechnical Society
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• v.19 no.5
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• pp.123-132
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• 2003

The final purpose of driveability analysis is to confirm whether a selected hammer drives a pile to a desired penetration depth and/or capacity without damage. The capacities from static analysis methods are meaningless if the pile cannot be driven to the required design depth and the ultimate capacity without damage. It often occurs that there are big differences between the capacities from measurements and calculations. It may be because the driveability is not evaluated due to the lack of engineers' understanding of the driveability of pile driving. The engineers in the field sometimes assume simply the penetration depth with standard penetration value only. In this study some test pilings with dynamic pile loading tests were performed to give an understanding about the driveability. The influence factors(driving resistance, impedance, material strength, hammer) on the driveability of steel piles were analysed with the monitoring data obtained from the dynamic load tests. It was shown that more cost-effective design can be made in case the driveability analysis and high strength steel pile are appropriately adopted in the design.

• Journal of Navigation and Port Research
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• v.41 no.3
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• pp.137-148
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• 2017

Port service level is a metric of competitiveness among ports for the operating/managing bodies such as the terminal operation company (TOC), Port Authority, or the government, and is used as an important indicator for shipping companies and freight haulers when selecting a port. Considering the importance of metrics, we developed software to objectively define and manage six important service indicators exclusive to container and bulk terminals including: berth occupancy rate, ship's waiting ratio, berth throughput, number of berths, average number of vessels waiting, and average waiting time. We computed the six service indicators utilizing berth 1 through berth 5 in the container terminals and berth 1 through berth 4 in the bulk terminals. The software model allows easy computation of expected ship's waiting ratio over berth occupancy rate, berth throughput, counts of berth, average number of vessels waiting and average waiting time. Further, the software allows prediction of yearly throughput by utilizing a ship's waiting ratio and other productivity indicators and making calculations based on arrival patterns of ship traffic. As a result, a TOC is able to make strategic decisions on the trade-offs in the optimal operating level of the facility with better predictors of the service factors (ship's waiting ratio) and productivity factors (yearly throughput). Successful implementation of the software would attract more shipping companies and shippers and maximize TOC profits.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.8 no.3
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• pp.239-245
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• 2010

There are 11,811 LWR spent fuels stored at reactor sites, as of 2009. Source terms based on reference spent fuel which represents entire spent fuels with bounding values in the aspect of source term has been applied to a design of nuclear installations, instead of those which are generated by weighting respective source term for each spent fuel. Simplified regression models to estimate total decay heat, radioactivity, and ingestion hazard index for spent fuel from Westinghouse-type reactors were developed in this study, because it can be used as a fundamental model for weighting source term for respective spent fuel to exclude conservativeness in source terms. It was found that the estimated source terms agreed with calculated value from ORIGEN-ARP within 5%. It was also found that the conservativeness could be excluded if the weight source terms were used as reference source term in the design. Therefore, it is expected that the developed regression model could be widely used in the conceptual design process of nuclear facilities related with storage and disposal of spent nuclear fuel.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.2 s.29
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• pp.133-140
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• 2007

Since early times, captain have been sailing to select the optimum route considering the weather, ship loading status condition and operational scheduling empirically. However, it is rare to find digitalized onboard route support system whereas weather facsimile or wave and swell chart are utilized for the officer, based on captain's experience. In this paper, optimal route safety assessment system which is composed of voyage efficiency and safety component is introduced. Optimum route minimizea ETA(estimated time of arrival) and fuel consumption that shipping company and captain are requiring to evaluate 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. Finally, It is assistance measure for ship's optimum navigation route safety planning & assessment.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.4
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• pp.361-371
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• 2015

This study analyzed the 91 cases of the statements for the Sea Area Utilization Consultation according to the developmental projects of ports and fishery harbors for 2012 2014 and the status of the record of document, and suggested the improvement way to go. The marine environmental timpact assessment items both marine chemistry such as water quality, sediment and marine biology such as benthic animal, plankton, and fisheries show highly rate of site survey. But, the utilization of those data through site survey is too low, and it is necessary to adopt the QA/QC for the reliability of survey data. The items of marine physics such as tide, tidal current analyzed based on references not a site survey. However, the simulation performed actively without calibration and verification compared to the result of site survey. When the projects of port and fishery harbor perform, it is necessary to monitor the physical parameter such as wave, tide and tidal current especially. Based on the scale and the type of project, we need introduce the system of scoping for prediagnosis the key assessment items and checklists.

• Journal of Korea Port Economic Association
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• v.23 no.4
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• pp.159-175
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• 2007

The purpose of this study is to examine the causal relationship between trading volume of freight and industrial growth in Korea ports, and to induce policy implications. In order to test whether time series data is stationary and the model is fitness or not, we put in operation unit root test, cointegration test. And we apply Granger causality based on an error correction model, Hsiao(1981) method and variance decomposition. The results indicate that the extent of causality between trading volume of freight and industrial growth is strong in order of Incheon port, Busan port, Gwang Yang port, Ulsan port. We can infer policy suggestions as follows; The port policy of government must be focused on re-adjusting investment among Korea ports and raising competitive power of Korea ports