• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.1091-1096
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• 2010

This study was conducted to provide reference data for designing an alarm system that can help prevent the overturning of a container crane under wind load. Two methods, namely, fluid-structure interaction (FSI) analysis and windtunnel test, were adopted in this investigation. To evaluate the effect of wind load on the stability of the crane, a 50-ton-class container crane that is widely used in container terminals was adopted as the analysis model and 19 values were considered as design parameters for wind direction. First, the wind-tunnel test for the reduced-scale container crane model was performed according to the wind direction by using an Eiffel type atmospheric boundary-layer wind tunnel. Next, the FSI analysis for the real-scale container crane was conducted using ANSYS and CFX. Then, the uplift force determined from the FSI analysis was compared with that determined from the wind-tunnel test. Finally, a formula to compensate for the difference between the results of the FSI analysis and the wind-tunnel test was proposed.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.413-421
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• 2005

Intra-block remarshalling is the task of rearranging into some target bays those containers which are scattered within around the block. If multiple transfer cranes installed in the block are all used together we may be able to complete the remarshalling task as early as possible. However, when multiple cranes are used simultaneously, there may occur significant delays if we do not carefully consider interferences between the cranes at the time of scheduling. Especially, delays caused by interferences occur more frequently in case of using non-crossing cranes. This paper presents an efficient heuristics method for assigning moves of containers to each crane and for determining an appropriate container moving order in a manner sensitive to the interferences. Simulation experiments have shown that the proposed method can effectively reduce delays in various environments.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.447-455
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• 2005

Intra-block remarshalling is the task of rearranging into some target bays those containers which are scattered within around the block. If multiple transfer cranes installed in the block are all used together we may be able to complete the remarshalling task as early as possible. However, when multiple cranes are used simultaneously, there may occur significant delays if we do not carefully consider interferences between the cranes at the time of scheduling. Especially, delays caused by interferences occur more frequently in case of using non-crossing cranes. This paper presents an efficient heuristic method for assigning moves of containers to each crane and for determining an appropriate container moving order in a manner sensitive to the interferences. Simulation experiments have shown that the proposed method can effectively reduce delays in various environments.

• Journal of Navigation and Port Research
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• v.36 no.8
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• pp.665-671
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• 2012

A remarshalling is studied as an important operational strategy in an automated container terminal to enhance the productivity of container handling. This means the rearrangements of the containers scattered at a vertical yard block. The dispatching problem for remarshalling is selecting the remarshalling operation considering the available operation time and deciding the operation sequencing to maximize the effectiveness of remarshalling. This study develops the optimal mathematical model for yard crane dispatching problem with mixed integer program and explains dispatching problem using an example. However it is difficult to apply this model to a field problem because of its computational time. Therefore, we compare the representative 5 dispatching rules for real world adaption. In a numerical experiment, maximum weight ratio(MR) rule shows an overall outstanding performance.

• Journal of Navigation and Port Research
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• v.32 no.10
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• pp.851-856
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• 2008

Construction of large-scale container ports with the productivity improvements in container cranes shortened time of staying port to increase the level of service it harbors efforts accelerated. About container crane system exerted on the input, which is designed to look good performance considering the states feedback control system. The states observer designed of container cranes state variables that are expected to measurement noise or particular measurement signal. In the status of existing research, the feedback gain matrix and the state observer gain matrix are searched by being separated solving. But the feedback gain matrix and the state observer gain matrix are searched by RCGAs at once that be used robust search method in this paper.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.287-301
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• 2022

This study aims to propose a crane-tip control method to intuitively control the end-effector vertically or horizontally for improving the crane work efficiency and to confirm the control performance. To verify the control performance based on experimental variables, a laboratory-scale crane was manufactured using an electric cylinder. Through a forward and reverse kinematics analysis, the crane was configured to output the position coordinates of the current crane-tip and the joint angle at each target point. Furthermore, a method of generating waypoints was used, and a dead band using lateral boundary offset (LBO) was set. Appropriate parameters were selected using bang-bang control, which confirmed that the number of waypoints and LBO radius were associated with positioning error, and the cylinder speed was related to the lead time. With increased number of waypoints and decreased LBO radius, the positioning error and the lead time also decreased as the cylinder speed decreased. Using the proportional control, when the cylinder velocity was changed at every control cycle, the lead time was greatly reduced; however, the actual control pattern was controlled by repeating over and undershoot in a large range. Therefore, proportional control was performed by additionally applying velocity gain that can relatively change the speed of each cylinder. Since the control performed with in a range of 10 mm, it was verified th at th e crane-tip control can be ach ieved with only th e proportional control to which the velocity gain was applied in a control cycle of 20 ms.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.31-32
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• 2006

본 논문은 중형엔진 조립과정에서 실린더 프레임 회전 작업에 사용하는 지그의 구조해석을 수행한 후, 지그의 안전성을 검토하고 지그의 경량화를 통하여 실용적인 지그 설계안을 제안하였다. 현장 작업자가 들 수 있는 최대 무게를 넘는 지그를 구조해석 모델로 선정한 후, 해석모델은 지그, 실린더 프레임, 볼트, 너트, 샤클 핀을 3차원 입체요소로 구성하고 ABAQUS/Standard를 사용하여 재료 비선형 및 접촉을 고려한 구조해석을 수행하였다. 구조최적화를 위하여 응력이 상대적으로 낮은 부위와 작업성을 고려하여 설계변수를 선정하고, 실험계획법의 직교배열표를 활용하여 설계변수에 대한 각 부위의 민감도와 경량화 모델을 도출하였다.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.775-778
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• 2008

기초의 지지방식 중 깊은 기초로 분류되는 말뚝기초는 일반적으로 고강도의 기성강관(Spiral Steel Pipe)을 재료로 한 말뚝을 사용하는 것이 설계 및 시공측면에서 유리하나, 현재 국내 외의 치솟는 건설원자재 비용 및 고유가에 따른 장거리 운반비용의 증가와 더불어 건설현장에서의 경제적 부담이 상당부분 증가되고 있는 실정이다. 특히, 개발후진국을 비롯한 건설 산업의 국제적 진출에 대한 활기와 더불어 해외현장 변동상황(원자재의 수급 문제에 따른 공기지연 및 경제성) 등을 고려하면 이에 대한 능동적인 대처가 절실할 수 있다. 본 사례는 중동지역 $\bigcirc\bigcirc$조선소의 이러한 현장여건을 고려하여 중 소하중 규모의 크레인 기초에 적용된 말뚝의 구조 해석적 검토와 지역 지반조건을 반영하여 안정하고 현지조달이 가능한 말뚝 재료의 변경을 제안한 경우이다. 본 검토에서는 기초 말뚝의 정역학적 허용지지력과 기초지반 조건을 고려한 항타관입 분석 및 크레인 이동하중을 고려한 응력해석을 실시하여 최대연직력, 모멘트, 전단력, 응력비 등을 비교하였으며, 동일한 검토조건하에서 결과를 바탕으로 변경 가능한 말뚝을 선정하였다. 기초지반에 대한 적정안전율을 갖는 허용지지력 및 구조적 안정성의 확보가 가능한 콘크리트 말뚝으로의 변경이 가능하며 상부하중 규모에 따라 설치간격에 따른 파일본수의 증 감이 발생되었다.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.131-139
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• 2009

It is critical to select the appropriate type of tower cranes for the construction of super tall buildings. However the selection is often made based on subjective personal experiences due to the lack of historical and analytical data. As a result, planning mistakes and efficiency errors sometimes occur. This research is to develop a system of hoisting analysis for appropriate tower crane selection and to provide a flexible statistical model based on the Burj Dubai project. In addition, this system hassupporting functions that can estimate the target construction period per floor, and a decision-making construction period computation method which is based on the characteristic of the selected tower cranes.

• Journal of Navigation and Port Research
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• v.30 no.6 s.112
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• pp.525-531
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• 2006

In the port, the yard crane is very important. If a container crane or a transfer crane is broken down, it costs a lot because of the delay of work during the period of repair or reorder. But, we don't have enough spare parts because of the high cost. It is necessary to maintain high reliability of the crane through effective preventive maintenance and failure analysis. In this paper, we analyse the function and failure mechanism of the transfer crane which is a main equipment in the yard Also, we standardize failures and maintenance works using the historical data of failure and maintenance. This study which is a basic work for effective equipment operation and maintenance will support reliability engineers to decide the optimal design of the next generation equipment and operational policy of equipment.