• The Journal of the Korea Contents Association
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• v.15 no.8
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• pp.46-52
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• 2015

Most stage directors and designers make use of controling and moving lots of stage set or device as a large automation device or machine to achieve dramatic effect in their performances. Specially, it is very important to use a programmable multi-chain hoist system which is able to move high speed as well as to lift heavy loads. This paper proposes a multi chain hoist servo system to lift or lower a heavy load of about l ton for public performances' stage. It is automatically operated, electrically driven by a control console with a PTP trajectory generation algorithm, a realtime network control algorithm, and 4 step sequential safety algorithm. The efficiency and performance of the developed system are verified through a series of experiments.

• 전자공학회논문지 IE
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• v.47 no.2
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• pp.47-53
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• 2010

The purpose of this paper is to build on automatic system for the shot ball transfer hoist. The shot ball is used to remove completely paint or leftovers before spreading the new paint on a large vessels surface. The shot ball is made of melted iron through cooling process, and it is transferred to hopper by electromagnet of hoist. Currently, the transfer process of the shot ball is performed by manual operation, and the transfer process is inefficient. So we have developed an automatic system to replace the manual system. The developed automation systems have efficient and accurate position control performance.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.10
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• pp.1109-1116
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• 2014

The wheelchair mechanism for a car that is proposed in this study primarily consists of a transfer mechanism and storage mechanism. The wheelchair transfer mechanism consists of a manipulator installed in the roof of a car, and performs the function of transferring the wheelchair from the driver's seat to the trunk. The wheelchair storage mechanism consists of a lifting hoist installed in the trunk of car, and performs the function of storing the transferred wheelchair in the trunk and safely fastening it in place. This study analyzed and reviewed various manipulators, including a vertical type, Scara type, and telescopic type, with the goal of selecting the best type of manipulator for the wheelchair transfer mechanism. The telescopic type was selected and applied because of its good load support and storage capabilities. In addition, with regard to the wheelchair storage mechanism, a slide hoist type that used a slide rail and lift wire and a rotating link hoist type that used a rotating mechanism consisting of a worm gear and link were analyzed and reviewed. The slide hoist type was selected and applied because it had an advantage in relation to trunk space utilization. This study proposed a wheelchair transfer mechanism for a car to support a conventional wheelchair user's movements, and in order to conform to the structure of a domestic welfare car for the disabled.

• The Safety technology
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• s.140
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• pp.62-63
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• 2009

• The Safety technology
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• no.148
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• pp.62-63
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• 2010

• Transactions of The Korea Fluid Power Systems Society
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• v.4 no.1
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• pp.1-6
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• 2007

The typical hydraulic system of hoist is composed of a hydraulic supply unit, a directional control valve, two pilot operated check valves, two flow control valves. The capacity coefficients of flow control valves should be adjusted for the hoist to operate at moderate speed and minimize the hydraulic energy loss. However, it is difficult to adjust the four capacity coefficients of flow control valves by trial and error for optimal operation. The steady state model of the hoist hydraulic system is derived and the optimal capacity coefficients of flow control valves are obtained using the complex method that is one kind of constrained direct search method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.543-548
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• 2006

This paper presents the vibration characteristics of scaffolding structures with a hoist according to payloads. In order to analyze the vibrational and structural characteristics for 20-step scaffolding structure, structural and vibrational characteristics for 2-step scaffolding structure were compared with some experimental results. The numerical results for natural frequencies of scaffolding structures have a good agreement with experimental ones. Through the numerical analysis, firstly, it is shown that the maximum stress of scaffolding structures is lower than von-mises yield criteria when four persons with total weight of 280kgf are working at the top of the scaffolding structures. Secondly vibration characteristics including natural frequencies and modes for scaffolding structures are shown in case of various kinds of moving masses.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.5
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• pp.1347-1354
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• 1994

This paper deals with the experimental research, including measurement and analysis and field survey, on the causes of occurring noise defective gear boxes in hoist production plant in order to reduce the fraction of their occurrence. In this reserch following investigations are performed : measurement and gear-boxes, examination of each machining process of production, measurement and analysis of dimensional accuracy of each part, comparative vibration test with exchanging inaccurate parts. From these investigations, it is found that the machining accuracy of pinion gear tooth thickness is the most sensitive factor of noise problem. By maintaining the tooth thickness error within 0.05 mm tolerance in the gear cutting process, the fraction of noise defective gear-boxes are greatly reduced to less than 2%, where the usual rate of it has been 20-50%.

• Transactions of The Korea Fluid Power Systems Society
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• v.5 no.1
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• pp.13-19
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• 2008

The typical hydraulic system of hoist is composed of a hydraulic supply unit, a directional control valve, counter balance valve, and flow control valves. The flow capacity coefficients of flow control valves should be adjusted so that the hoist is operated at moderate speed and the hydraulic energy loss is minimized. However, it is difficult to adjust the flow coefficients of flow control valves by trial and error for optimal operation. Here, the steady state model of the hoist hydraulic system including the differential cylinder circuit is derived and the optimal flow capacity coefficients of flow control valves are obtained using the complex method that is one kind of constrained direct search method.

• Journal of the Korean Society of Marine Environment & Safety
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• v.21 no.1
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• pp.91-96
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• 2015

In this study, we performed a study on prevention of the escape hoist heavy objects on the basis of the case of a disaster occurring during crane operations. A safety hook of the automatic fastening and coupling method by the conventional coupling method, the weight of the outside consisting of a combination of a safety ring structure was designed and manufactured. The main mechanism three-dimensional detail design and structural analysis confirmed the structure and stability of small strain than the allowable stress of the Safety Hook with X-jog through. Safety factor was confirmed to represent the average 1.5 to 1.2 higher than the safety factor to be considered in the general design structure. Therefore, Safety Hook and X-jog in the present study is to be operated upon structural stability is a structure attached to the hoist and crane are considered sufficient.