• Korean Journal of Construction Engineering and Management
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• v.10 no.6
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• pp.127-134
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• 2009

This study aims to provide an optimal model for the layout of multiple tower cranes and material stockyards which have multiple candidate positions. In a high-rise building construction, the positional allocation of tower cranes and material stockyard has an effect on the travel time of material hauling. In addition, in case of using multiple tower cranes, specific location of a tower crane allocated to each material determines the efficiency of the works. Current optimal model limited to the optimization of position of single tower crane and material stockyards. This study suggests optimal model both for the positions of multiple tower cranes and material stockyards. Layout of multiple tower cranes requires additional allocation of each crane to each material hauling and control on the minimum distance between tower cranes. This optimization model utilizes genetic algorithm to deal with complex interaction on the candidate positions of multiple tower cranes, material stockyards, and types of materials. In order to identify its utility, case study was performed.

• Proceedings of the Korea Society for Simulation Conference
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• 1998.10a
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• pp.25-35
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• 1998

정부는 자동화컨테이너터미널을 구축하기 위한 기초연구를 수행하고 있다. 자동화컨테이너터미널은 선박하역을 담당하는 컨테이너 크레인과 애드크레인을 무인 혹은 유/무인 자동제어가 가능하도록 설계하고 선박과 야드간 이동은 AGV를 이용하여 자동화함으로써 생산성 향상, 인건비 절감 등을 목표로 하고 있다. 본 연구에서는 1척의 선박이 접안할 수 있는 가상의 자동화컨테이너터미널에서 컨테이너 크레인 수, AGV 대수, 야드 크레인수 등을 변화시켜가면서 터미널의 생산량을 추정할 수 있는 시뮬레이션 모델을 개발하여 제시하였다. 또한 향후 자동화컨테이너터미널의 최적 설계 및 운영을 위한 시뮬레이터를 개발하기 위한 구상을 제시하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.5D
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• pp.705-717
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• 2011

The number of horizontal tower cranes, major hoisting machineries for lifting approximately 50% of entire materials in construction projects, is rapidly increasing, but a number of accidents related to the tower cranes are being continuously occurred in construction sites as well. In particular, telescoping works in the horizontal tower cranes have showed the greatest safety concerns such as falls and collapses. It is due to the fact that tasks inserting a new mast in the space made after raising telescoping cage by fluid pressure and ascending it to the required height in the telescoping works include a series of dangerous factors in safety aspects, and might cause very serious and unexpected accidents in construction sites. The primary objective of this research is to propose two conceptual models for automating the telescoping work in horizontal tower crane and conduct their technical feasibility analyses. In this study, a design concept, a position control system using hydraulic cylinders is suggested as a better alternative for automating the telescoping work. Its potential safety improvement rate compared to the conventional method is also analyzed and presented in this study.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.192-195
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• 2010

본 논문에서는 해상 크레인과 중량물의 동적 거동을 시뮬레이션하기 위해, 유한 요소 정식화(finite element formulation)를 이용하여 해상 크레인의 붐(boom)을 탄성체로 모델링 하였다. 붐은 3차원 탄성 빔(beam) 요소로 가정하고, 각 요소의 변형에 의한 변위는 형상 함수(shape function)과 절점 좌표(nodal coordinate)를 이용하여 정의하였다. 변형 변위를 이용하여 탄성 붐의 강성 행렬(stiffnes matrix)을 유도하고, 탄성 변위를 포함하는 위치 벡터를 이용하여 질량 행렬을 유도한다. 해상 크레인과 중량물로 이루어진 운동 방정식에 탄성 붐을 포함하여 유연 다물체계(flexible multibody system) 운동 방정식을 구성한다. 외력으로는 선박 유체정역학적 힘, 유체동역학적 힘, wire rope의 장력, 중력 그리고 계류력(mooring force)이 고려되었다. 먼저 요소의 개수를 변경하며 탄성 붐의 동적 거동을 시뮬레이션 하여, 유한 요소 정식화를 이용한 모델링의 타당성을 검증하였다. 그리고 해상 크레인과 중량물의 동적 거동 시뮬레이션에 탄성 붐 모델을 적용하였다.

• Journal of the Korea Society of Computer and Information
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• v.20 no.1
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• pp.237-246
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• 2015

In this paper, Improved productivity models of container terminal are provided by utilizing a simulation considering Tandem-lift Quay Crane and transport vehicle of container's high productivity 'Alternative ship-to-yard vehicles.' Feature of this method is deriving the data of tandem-lift Quay Crane and Alternative ship-to-yard vehicles, estimating the productivity model of tandem-lift Quay Crane by using regression analysis. Tandem-lift Quay Crane is equipment of loading and unloading to increase productivity approximately by 2 time existing (single, twin) Quay Crane by dealing with four 20ft containers or two 40ft containers at the same. Alternative ship-to-yard vehicles can transfer containers(4TEU) more than existing Yard Tractor. This paper is deriving the optimal combination showing the highest productivity by using simulation considering Tandem-lift Quay Crane and Alternative ship-to-yard vehicles on container terminals and developing estimating model of productivity by using regression analysis using data of simulation.

• Journal of Navigation and Port Research
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• v.35 no.1
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• pp.63-70
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• 2011

This paper discusses the problem of scheduling berth and container cranes simultaneously in port container terminals. A mixed-integer programming model is formulated by considering various practical constraints. A heuristic algorithm is suggested for solving the mathematical model. A numerical experiment was conducted to test the performance of the suggested heuristic algorithm.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.191-196
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• 2015

해상 pedestal 크레인은 각종 운송물을 선박에 싣거나 내리는 해상 운송에 필수적인 장비이다. 따라서 구조적 안전성을 가지는 크레인 설계가 요구된다. 그의 일환으로 수행된 '해상 pedestal 크레인의 설계 개선을 위한 연구'에서는 기존 크레인의 기초 설계에 대해서 구조적 안전성올 평가하여 개선 방안을 제시하였다. 또한 좌굴 안정성 향상을 위한 보강재 설계를 수행하였다. 하지만 상세설계 관점에서 미비한 점이 있어 이를 보완할 필요성이 있다. 안전성 평가를 위해 필요한 응력을 계산하기 위해 EDISON-CSD프로그램을 통해 유한요소모델 해석을 활용한 구조해석을 수행하였다. 효율적인 해석을 위해 상세설계에 필요한 부분영역을 선택하여 모델링 하였으며 전체영역에서의 해석 결과 값을 등가 힘, 등가 모멘트로 환산하여 경계조건으로 부여하였다. 보강재간의 교차점 형상이 안전성에 미치는 영향을 보기위해 stiffener와 diaphragm의 교차점 형상(반원, 정사각형, 사다리꼴)에 따라 안전성 평가를 수행하였고, 안전 여유의 유효한 차이를 보이지 않음을 확인하였다. 평가에 필요한 응력계산을 위해 또한 Diaphragm의 좌굴에 대한 영향을 고려하기 위해 설계 규격 DNV-RP-201 8장(Buckling of girders)을 분석하였고, 안전성 평가에 반영하였다. 또한 실제 현장에서 보편적으로 사용되는 angle 형상 stiffener의 치수 도출을 위해 최적설계를 수행하였고, 모든 설계 제한조건을 만족하면서 최소의 무게를 가지는 합리적인 치수를 도출하였다.

• Journal of Navigation and Port Research
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• v.33 no.5
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• pp.331-337
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• 2009

Container crane is main equipment in container terminals and it determines the productivity and the efficiency of container terminals. The typical type of container cranes has the single trolley and one among advanced types of them has the dual trolley. The objective of this paper is to analyze the buffer size of a container crane with the dual trolley in container terminals. We present a simulation model for analysing the buffer space of a container crane with the dual trolley. The buffer space is located between main trolley in sea-side and second trolley in yard-side. We performs various simulation experiments and analyze the buffer size to estimate the required productivity.

• Journal of Navigation and Port Research
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• v.29 no.5 s.101
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• pp.409-413
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• 2005

The existing control techniques for the operation of a container crane satisfy the terminal condition of controlled variables, but the outcome of input computation is inadequate for the operation of the crane due to heavy movement of inputs. In this study, a new control technique employing a nonlinear model of the crane is proposed to compute the inputs approximated with the 4th-order Chevyshev function. The control objective of sum of absolute deviations is minimized, and the optimization is conducted with the simplex algorithm. The inputs and outputs computed from the proposed technique were compared with the results of the previous study to show that they give more stable crane operation than the existing control technique.

• Korean Journal of Construction Engineering and Management
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• v.7 no.1 s.29
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• pp.80-88
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• 2006

Construction graphical simulations usually do not reflect physical properties of construction equipment and material because there are restricted to the geometric model. The complete description of construction operations is difficult for graphical simulation without a physical modeling. The object of this research is to enhance the functionality of restricted simulation system to geometric model. And research is conducted to overcome the limitation of current construction graphical simulation system through the connection geometric model and physical model with the physical properties of construction equipment and material such as crane's cable oscillation. The motion equations for the oscillation of crane cable as a result of the trolley's movement and the boom's rotation were derived. The equations were solved through numerical analysis and the results were simulated visually. The realistic description with physical modeling of construction operations will contribute for ensuring preliminary against risks and improving constructability as well as the application of various fields.