• Journal of Korean Institute of Industrial Engineers
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• v.33 no.1
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• pp.110-125
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• 2007

Various different types of yard cranes are used in container terminals. Examples are rubber tired gantry cranes,rail mounted gantry cranes, overhead bridge cranes, dual rail-mounted gantry cranes, and automated stacking cranes. The kinematics and handling characteristics of these yard cranes are different from each other. Ttiis study analyses charactehstics of generic types of yard cranes which represent various yard cranes m practice Demg used in several types of block layouts, Considering specifications of yard cranes and block layouts, expected cycle times and variances of the cycle time are estimated for different handling activities.

• The Korean Journal of Ecology
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• v.24 no.2
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• pp.77-80
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• 2001

We investigated the habitat use of cranes, and suggested the proper way to protect and manage the cranes in Cheolwon Basin, which is the most important wintering ground of cranes in Korea. Field surveys were conducted in the wintering seasons from Nov. 1994 to Feb. 1995, and from Nov. 1997 to Feb. 1998. The habitat loss and environmental changes by the road construction and agricultural field rearrangement might have affected the distribution of the cranes. The distribution of cranes seemed to be related with the density of rice grains remained in rice paddies.

• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.1
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• pp.95-102
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• 2018

This paper proposes a dual lifting and its cooperative control system with two different kinds of floating cranes. The Mega-erection and Giga-erection in the ship building are used to handle heavier and wider blocks and modules as ships and off-shore platforms are enlarged. However, there is no equipment to handle such Tera-blocks. In order to overcome the limit on performance of existing floating cranes, the dual lifting is proposed in this research. In the dual lifting, two floating cranes are well-coordinated to add up the lift capabilities of both cranes without any loss such that virtually a single crane is lifting, maneuvering and unloading. Two main constraints for the dual lifting are as follows: First, two barges of floating cranes should be constrained as a rigid body not to cause a relative motion between two barges and main hooks of the two cranes should be controlled as main hooks of a single crane. In order words, it is necessary to develop the cooperative control of two floating cranes in order to sustain a center of gravity of the module and minimize the tilting angle during the lifting and unloading by the two floating cranes. Two floating cranes are handled as a master-slave system. The master crane is able to gather information about all working conditions and make a decision to control the individual hook speed, which communicates the slave crane by TCP/IP. The developed control system has been embedded in the real floating crane systems and the dual lifting has been demonstrated five times at SHI shipyard in 2015. The moving angles of the lifting module are analyzed and verified to be suitable for hoisting control. It is verified that the dual lifting can be applied for many heavier and wider blocks and modules to shorten the construction time of ships and off-shore platforms.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.7
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• pp.717-724
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• 2013

Industrial cranes are indispensable equipment in heavy industry. However, unwanted vibrations in cranes often cause accidents. Input shaping is widely accepted as a useful tool for removing residual vibration in cranes. A unity magnitude zero vibration (UMZV) input shaper is often used for cranes driven by on-off-type motors. However, although a UMZV input shaper minimizes residual vibration, the input shaper cannot prevent the crane from moving slightly further than expected from the original command. This paper describes an improved method of input shaping that can compensate for position inaccuracies, as well as remove the residual vibration of cranes. Experiments were performed to validate the proposed input-shaping method, illustrated through numerical simulations.

• IE interfaces
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• v.14 no.1
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• pp.67-78
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• 2001

This paper describes the simulation study which estimates the container crane efficiency in container terminal. In most simulation studies, it is assumed that container cranes are available at any time. Though the failures of container cranes don't occur often, they are very serious problems on terminal efficiency. As usual, the failures of container crane cause arrived ships to delay the departure time. In this study, a queueing simulation model for container terminal, which focuses on the failures of container cranes, is designed. The simulation approach appears to be the most appropriate one because it allows to avoid the usual exponential assumption on interarrivals of ships and service times of container cranes. Using the developed model, we tested the efficiency of container cranes considering failures with a real system size and performed the simulation experiment on real container terminal to validate the developed simulation model. The results of simulation experiment were analyzed using output statistics, which include the waiting times of vessels and yard tractors, the utilization for container cranes, and the berth occupancy rates.

• Journal of the Korea Institute of Building Construction
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• v.12 no.3
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• pp.358-368
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• 2012

On most construction sites, the arrangement of tower cranes is decided by site engineers based on their own experience, which can cause cost overruns and delays in the lifting work. Although many researchers have conducted studies on tower crane arrangement using computer modeling and knowledge-based expert systems as well as mathematical models, no research has aimed to develop an algorithm to identify an optimum solution among several alternatives for installation areas of tower cranes satisfying the conditions of lifting work. The objective of this study is to develop an automatic arrangement algorithm for tower cranes used in high-rise apartment construction. First, as a new concept, a possible installation area of tower cranes was suggested. Second, after proposing several alternatives based on the installation points suggested in this study, an algorithm analyzing the economic feasibility of tower cranes was developed considering the rental, installation and removal costs. Third, a case study was conducted to prove the validity of the developed algorithm for selecting and installing an effective set of tower cranes at minimum cost.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.9
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• pp.1032-1039
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• 2011

This paper presents results of input shaping to industrial cranes. A brief theoretical background for input shaping is described. Several examples of input shaping application to sway regulation for industrial cranes are presented. The presented results show that input shaping is very useful for industrial cranes.

• 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.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.6
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• pp.510-517
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• 2005

In this paper, an open architecture control system for automated container cranes is investigated. The hardware architecture for automating cranes is first discussed. A standard reference model for cranes based upon the OSACA platform is proposed, in which three modules are suggested: hardware module, operating system module, and application software module. Finally, a hybrid control system combining deliberative and reactive controls for autonomous operations of the cranes is implemented.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.12
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• pp.1919-1925
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• 2001

Overhead cranes consist of trolley, girder, rope, objects, trolley motor, girder motor, and hoist motor. If objects are regarded as mass point, and the acceleration of hoisting motion for objects is neglected, analytical model of overhead cranes becomes a nonlinear model because the length of a rope changes. Equations of motion this model is derived of simultaneous differential equations fur motors and object. Positions of the model are controlled by optimal inputs which obtain from a nonlinear optimal control method. From the results of computer simulation, even if initial states of objects suing, it is founded that position of overhead cranes is controlled, and that swing of objects is suppressed.