• 대한조선학회논문집
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• 제49권2호
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• pp.164-173
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• 2012

Landing ship tank with well dock has the important mission transferring troops or landing equipments from sea to shore. Such transfers are usually carried out using landing crafts, which are loaded or unloaded in flooded well dock. In this situation, as relative motions are occur between well dock and landing craft, safety verifications are demanded. In this paper, seakeeping and safety performances are investigated through model test. First of all, well dock dimensions are reviewed and model tests are performed with sea state 3&4 in 180degree wave direction. Model tests are conducted for three relative positions and seakeeping performances are investigated each position.

• Structural Engineering and Mechanics
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• 제74권4호
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• pp.521-532
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• 2020

A floating dry dock is an advanced structure that can provide a solution for dry dock space shortages. The critical point in floating dock operation is compensating the deflection caused by a heavy payload by adjusting the water level in the ballast system. An appropriate ballasting plan warrants safe and precise construction on a floating dock. Particularly, in the case of a 2D floating dock, ballasting plan evaluation is crucial due to complex deformation modes. In this paper, we developed a method to calculate the optimal ballasting plan for accurate and precise construction on a 2D floating dock. The finite element method was used for considering the flexibility of the floating dock as well as the construction blocks. Through a gradient-based optimization algorithm, the optimal ballasting plan for the given load condition was calculated in semi-real time (5 min). The present method was successfully used for the actual construction of an offshore structure on the 2D floating dock.

• Ocean Systems Engineering
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• 제4권2호
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• pp.99-115
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• 2014

When caissons are mounted on a floating transportation barge and towed by a tug boat in waves, motion of the floating dock creates inertia and gravity-induced slip forces on the caisson. If its magnitude exceeds the corresponding friction force between the two surfaces, a slip may occur, which can lead to an unwanted accident. In oblique waves, both pitch and roll motions occur simultaneously and their coupling effects for slip and friction forces become more complicated. With the presence of strong winds, the slip force can appreciably be increased to make the situation worse. In this regard, the safety of the transportation process of a caisson mounted on a floating dock for various wind-wave conditions is investigated. The analysis is done by both frequency-domain approach and time-domain approach, and their differences as well as pros and cons are discussed. It is seen that the time-domain approach is more direct and accurate and can include nonlinear contributions as well as viscous effects, which are typically neglected in the linear frequency-domain approach.

• 한국항만경제학회지
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• 제33권1호
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• pp.1-10
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• 2017

물류센터의 생산성 및 안전도 향상을 위한 기계화 및 자동화가 급속도로 진행되고 있으며, 작업자들의 효율적이고 안전한 작업 지원을 위한 다양한 연구들이 진행되고 있다. 하지만, 집배송차량과 물류센터 간 연결 역할을 하고 있는 하역작업장의 경우는 아직까지도 지게차 위주의 작업이 이루어지고 있다. 또한 지게차와 작업자가 같은 공간에서 함께 작업함에 따라 이로 인한 안전사고도 자주 발생하고 있다. 따라서 본 연구에서는 상하역자업장의 기계화 및 자동화를 통해 생산성과 안전성 향상의 문제를 해결하기 위해 여러 개의 팔레트를 한꺼번에 작업할 수 있는 일괄 하역장비들에 대해 소개하였다. 일괄 하역장비들은 새로운 개념의 하역장비로 적용 시 효율적인 운영을 위해 필요한 적정 장비 대수는 범용 4대, 전용 3대이다. 작업장 면적은 장비크기와 부가공간을 포함하여 범용 $256.28m^2$, 전용 $207.00m^2$가 필요하며 이를 기반으로 작업장 면적 및 일괄 상하역장비를 고려한 상하역작업장을 설계하였다. 또한 NPV, IRR, PBT 등 경제성 분석을 실시하였으며 주요 변수에 대한 민감도 분석을 수행하였다.

• Structural Engineering and Mechanics
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• 제54권5호
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• pp.999-1016
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• 2015

In this paper, we introduce a new method for assembly of shipbuilding blocks at sea and present its feasibility focusing on structural safety. The core concept of this method is to assemble ship building blocks by use of bolting, gluing and welding techniques at sea without dock facilities. Due to its independence of dock facilities, shipyard construction capability could be increased considerably by the proposed method. To show the structural safety of this method, a bulk carrier and an oil tanker were employed, and we investigated the structural behavior of those ships to which the new block assembly method was applied. The ship hull models attached with connective parts are analyzed in detail through finite element analyses, and the cargo capacity of the bulk carrier is briefly discussed as well. The results of these studies show the potential for applying this new block assembly method to practical shipbuilding.

• Bulletin of the Korean Chemical Society
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• 제29권5호
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• pp.921-927
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• 2008

Discovery of $\alpha$-glucosidase inhibitors has been actively pursued with the aim to develop therapeutics for the treatment of diabetes and the other carbohydrate mediated diseases. As a method for the discovery of new novel inhibitors of $\alpha$-glucosidase, we have addressed the performance of the computer-aided drug design protocol involving the homology modeling of $\alpha$-glucosidase and the structure-based virtual screening with the two docking tools: FlexX and the automated and improved AutoDock implementing the effects of ligand solvation in the scoring function. The homology modeling of $\alpha$-glucosidase from baker’s yeast provides a high-quality 3-D structure enabling the structure-based inhibitor design. Of the two docking programs under consideration, AutoDock is found to be more accurate than FlexX in terms of scoring putative ligands to the extent of 5-fold enhancement of hit rate in database screening when 1% of database coverage is used as a cutoff. A detailed binding mode analysis of the known inhibitors shows that they can be stabilized in the active site of $\alpha$- glucosidase through the simultaneous establishment of the multiple hydrogen bond and hydrophobic interactions. The present study demonstrates the usefulness of the automated AutoDock program with the improved scoring function as a docking tool for virtual screening of new $\alpha$-glucosidase inhibitors as well as for binding mode analysis to elucidate the activities of known inhibitors.

• 한국항해항만학회지
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• 제44권3호
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• pp.181-186
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• 2020

지금까지 컨테이너 자동화 터미널의 설계 및 운영 모델 개발은 주로 수출입 화물의 양적·하 기능에 특화된 서구 항만을 대상으로 수행되었기 때문에, 부산항처럼 다양한 On-Dock 서비스가 요구되는 컨테이너 항만에서는 자동화 터미널의 도입과 운영에 많은 제약이 따른다. 이에 본 연구의 목적은 부산항을 사례로 현재 컨테이너 물동량 구조와 터미널 내부 운영 특성을 진단하고, 기존 자동화 터미널 운영 모델의 부분적인 변경을 통해 효과적인 공컨테이너 관리와 함께 터미널 운영비용을 절감하는 방안을 제시하는 것이다. 기존 수직 배열 자동화 컨테이너 터미널에 '인터체인지 이송 모델'을 적용하여 시뮬레이션 한 결과, 수정된 운영 모델은 구내 이송장비를 추가로 투입해야 하는 불리함에도 불구하고 기존 운영 모델 대비 최대 22%의 TAT 단축과 함께 연간 터미널 매출의 9.4%에 달하는 운영비용 절감이 가능한 것으로 나타났다.

• 한국해양공학회지
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• 제23권1호
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• pp.104-108
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• 2009

As the demands of ocean resource development increase, many offshore structures are required. To cope with the active ocean developments, many types of construction methods have been applied for offshore facilities, including oil, gas and harbors. One of the challenges is to transport and install the heave bridge caisson. Several construction methods are well understood. However, for the sake of safety and reliability, the F/D installation method can be utilized. While the caisson is carried by an F/D, the mooring force of the tug boat and the structure stability from exiting motions in the dock should be checked against external loadings and sea conditions. The external loads can be classified with wind force, current force, and wave force. In the stability analysis, transportation velocity and draft of F/D are important factors. The dynamic stability and hook load for crane barge installation for the same caisson are also studied. Considering external loads and dominant factors, the stability of caisson during transportation has been investigated.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 심포지엄 논문집 정보 및 제어부문
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• pp.246-248
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• 2005

The power plants have a loading dock and unloading device for the diverse kinds of fuel such as the bituminous coal and natural gas imported by the sea from all over the world. To unload the coal in the ship not only in the environment-friendly manner but also in the cost-effective way, the new type of heavy equipment loaded with additional features as well as excavator and the remote controller to maneuver this equipment are developed. This heavy equipment, which can be used to unload the coal in the ship in conjunction with CSU (Continuous Ship Unloader), and the remote controller are endorsed by the related code and laws. With the remote controller, the field workers can operate the unloading equipment at the remote place far from the equipment as well as in the cabin for themselves without tile remote controller.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제15권12호
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• pp.881-890
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• 2009

고에너지 물리나 생명공학 분야의 거대 문제를 풀기 위해서는 다수의 계산 자원이 요구되는데 이는 하나의 그리드 환경을 통해서는 확보되기가 어려울 수 있다. 각 그리드 환경에서 각각의 사용자 인터페이스를 통해서 작업을 제출할 수 있지만, 수 백 개 이상의 작업들로 이루어지는 거대 문제를 각기 다른 그리드 환경에서 따로 관리하기에는 많은 비용과 노력이 요구될 수 있다. 본 논문에서는 이와 같은 문제점을 그리드 사용자 인터페이스 시스템인 Ganga의 Gridway 백엔드와 InterGrid 백엔드를 개발하여 이 기종의 그리드 환경에서 동일한 사용자 인터페이스를 제공하여 해결하고자 한다. 우리는 Globus 기반의 그리드 자원을 백엔드로 사용할 수 있도록 Ganga의 Gridway 백엔드 모듈을 개발하였다. 또한 gLite 기반의 그리드 자원과 Globus 기반의 그리드 자원을 함께 사용할 수 있도록 지원하기 위해서 InterGrid 백엔드 모듈도 개발하였다. 이와 함께, 개발된 백엔드 모듈들의 실용성을 보여주기 위해서 WISDOM 프로젝트에서 사용되고 있는 AutoDock 프로그램을 지원하는 Autodock application 플러그인을 개발하여, Globus 기반의 PRGMA 자원과 gLite 기반의 EGEE 자원을 동시에 활용하는 연동실험을 수행하였다.