• Journal of the Society of Naval Architects of Korea
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• v.48 no.2
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• pp.165-170
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• 2011

In this paper, wind force coefficient by wind tunnel experiment is obtained to compute the accurate wind force of the gantry crane model to be used for mobile harbor ship. The first crane model was tested under 20, 30, 40, 52m/s, partially 58m/s and the wind force coefficient is about 2.0 which is very close to the suggested theoretical value. The other is the more reliable crane model and tested under 20, 30, 40m/s also giving the similar realistic wind force coefficient. Also structural analysis of crane model was performed giving the reliable stress level. Since the rolling effect is important for mobile harbor ship, the safety of the crane on the ship needs to be guaranteed. For this, using the computed reaction forces, a tie-down design is suggested which connects the crane and ship to resist the turnover motion of the crane.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2005.10a
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• pp.235-240
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• 2005

Articulation type container cranes are the boom forms an inverted L shape when raise. The inner boom section is nearly vertical when raise and the outer boom section is nearly horizontal. Articulation type container cranes were developed as a lower height crane to meet aircraft clearance requirements. Because the height of an Articulation type container crane is about 70m, the crane is subjected to the effect of Wind load. Therefore, the problem on the effect of Wind load is receiving carefully study. The researches for the effect of wind load on the structural stability of a conventional container crane are conducted. In this study, we carried out the investigation for an articulation type container crane. When a wind load is applied to a container crane, we analyzed the reaction force distribution at each supporting point of a crane with respect to a wind load direction and the effect of the change of the machinery house location on the structural stability rf a crane by carrying out Finite Element Analysis.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.30 no.3
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• pp.57-67
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• 2012

This study draws the following conclusions about the nature garden culture with crane that is a dynamic landscaping factor introduced into nature garden by analyzing the literatures on cranes written and landscapes painted in Chosun Dynasty. First, crane symbolizes such Buddhist, Taoist and Confucius media as appearance of Buddha, desire for Taoist hermit world and long life, and a solitary's life of proud loneliness. It has been recorded that crane was raised from the Three Nations Era till the Japanese occupation and Confucius scholars in Chosun Dynasty opened shows concerning crane or formed literature groups enjoying poems of it, and often using crane as their denial of going into government service. Second, in order to introduce crane to nature garden, people caught wild crane and made a fence and some kind of pond for their growth. In addition, crane was strictly managed by appointed slaves and they trained crane for dancing and then tended to allow a crane to play on the yard in terms of abstract meaning or got two cranes free in consideration of their ecology. Third, for more appreciation of crane and the expression of some symbolism matching for it, both plum and pine, which mean a solitary's life and long life respectively, were planted in nature garden. And, Confucius scholars in Chosun Dynasty also enjoyed their refined tastes with appreciation, napping, reading and playing the harp, accompanied by crane. As aforementioned, Confucius scholars in Chosun Dynasty did not only draw the meaning symbolized by cranes and write poems about such symbolic meaning, but also positively introduce crane into nature garden as a dynamic landscaping factor, so that they enjoyed synesthetic senses including looks, motions and sounds of cranes for their refined tastes.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.4
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• pp.128-135
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• 2005

Overhead crane systems consist of trolley, girder, rope, objects, trolley motor, girder motor, and hoist motor. The dynamic system of these systems becomes a nonlinear state equations. These equations are obtained by the nonlinear equations of motion which are derived from transfer functions of driving motors and equations of motion for objects. From these state equations, Lyapunov functions of overhead crane systems are derived from integral method. These functions secure stability of autonomous overhead crane systems. Also constraint equations of driving motors of trolley, girder, and hoist are derived from these functions. From the results of computer simulation, it is founded that overhead crane systems is secure.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.2
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• pp.344-348
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• 2012

The knuckle crane design in Korea has been performed by assuming a cantilever beam type structure and numerically analyzing design data and finally improving the stiffness by replacing material. In our study, a complete finite element model of the knuckle crane is constructed and finite element analysis is conducted using Optistruct. Structural optimization to reduce the weight of the knuckle crane is processed by applying maximum loading condition at the largest radius of motion, which is the worst case of loading condition. As the results, existing over stiff design in a knuckle crane is corrected to meet a desired design limit and overall weight is reduced, which eventually leads to a reduction of $CO_2$ emission.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.4
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• pp.142-147
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• 2000

An overhead crane system which transports an object by girder motion, trolley motion, and hoist motion becomes a nonlinear system because the length of a rope changes. To develope the position control algorithm for the nonlinear crane systems, we apply a nonlinear optimal control method which uses forward and backward difference methods and obtain optimal inputs. This method is suitable for the overhead crane system which is characterized by the differential equation of higher degree and swing motion. From the results of computer simulation, it is founded that the position of the overhead crane system is controlled, and the swing of the object is suppressed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.746-751
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• 2004

Demands for higher productivity in container terminal environments continues to escalate consideration of equipment upgrades. And then transportation of containers using the automated container crane becomes more and more important for productivity enhancements. Introducing a hybrid control architecture to the container crane, it provides a effective means to the automated operation of the container crane. This paper addresses the methodology for automation of container cranes. In addition, this paper proposes a new control architecture for the automated container crane and explains each component of that architecture. The control architecture is composed of a deliberative control layer, a sequencing layer, and a reactive control layer. The proposed architecture is applied to a dual-hoist double-trolley container crane.

• Journal of Advanced Research in Ocean Engineering
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• v.1 no.2
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• pp.85-93
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• 2015

The nonlinear time-domain analysis method was implemented to carry out a series of integrated simulations for a deep-water crane vessel system composed of four sub components, including a floating vessel, lifted equipment, hoisting cable and dynamic positioning (hereinafter DP) system. The analysis of the coupled dynamics consists of the crane vessel and equipment connected using the crane wire, and the DP is modeled according to the wind, wave and current conditions. The DP systems were numerically implemented using a classical PD feedback controller, and various simulations of the deepwater installation were conducted using different conditions in order to evaluate the global performance of the floating crane vessel combined with the DP system.

• Proceedings of the Korean Society for Quality Management Conference
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• 2006.11a
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• pp.315-320
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• 2006

Container crane in container terminal have a lot of parts, and a crane breakdown affects the productivity of terminal. In this paper, we decide Preventive Maintenance (PM) schedules for container crane in container terminals. We define structure of container crane using three model. Also we develop a simulation system and genetic algorithm for decision PM schedules based on failure and maintenance data collected from container terminal. We compare the work schedule with PM schedules of container crane, then regulate PM schedules using heuristic method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.465-470
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• 2004

In this paper, an open architecture control system for automatic container cranes is investigated. A standard reference model for cranes, which consists of three modules； hardware module, operating system module, and application software module, is proposed. A hybrid control architecture combining deliberative and reactive controls for the autonomous operation of the cranes is proposed. The main contributions of this paper are as follows： First, a new reference platform for the crane control system is proposed. Second, by analyzing the structure of a container crane, implementation strategies for the automatic container crane are described.