• Proceedings of the KIEE Conference
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• 2004.05b
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• pp.156-158
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• 2004

In the ATs(Auto-Transformers)-fed AC electric railroad system, the trolley wire with high power is supported with a messenger by the dropper. As the dropper maintains the height of the trolley wire and plays a role in distributing the supply power, it should be stabilized in that an electric and mechanical character accord ins the change of the open air circumstance and constructed easily. Consequently, this paper propose C5111 Sn(3.5$\sim$4.5%) and hexagonal round bolt for the way of the efficient stabilization as a result of the test that the correlation of the Sn content and the change of temperature affect a character of product.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.10a
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• pp.424-429
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• 2013

The trolley carrying the pod moves along by the airfield runway. The pod through the trolley are subjected to vibration arising from the ground state, the precision optical components in the pod can have a significant impact. The road tests were conducted by using the measurement pod to remove the risk for the project. The measurement pod was composed with the ACRA, sensors, battery. The accelerometers were attached to get the acceleration through the road condition. The PSD envelop was calculated by FFT from the acceleration. The driving safety was proven through comparing the measurement data and MIL-STD-810G specification.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.9
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• pp.166-171
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• 1999

An overhead crane system consists of trolley, girder, rope, object, trolley motor, girder motor, and hoist motor. An analytic model which derived from the modelling of the overhead crane system is nonlinear model which includes the swing and the twist angle of the object. this model consists of the equation of motion for motors and object. If the swing angle and the acceleration of Z for the object are small, this model becomes a simple nonlinear model which doesn't include the swing and the twist angle of the object. From the results of computer simulation, the characteristics of an actual overhead crane system could be predicted by the simple nonlinear model.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.719-727
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• 2021

In the field of architecture, retractable devices capable of responding flexibly to the environment have been applied widely to large structures. Among these devices, the aesthetically pleasing retractable membrane is lightweight so that the membrane can be opened easily using only a traction device. On the other hand, because the towed membrane moves as it is connected to the main cable by a trolley, the number of trolleys needed increases in proportion to the roof's area. This study proposes an optimal model for an open-type trolley (OTT), which is used widely in these devices, using topology optimization. The analysis used the ANSYS program. A new model was proposed based on the results and reviewed through the feedback. Through this process, it was possible to develop a prototype with increased durability and reduced weight. For OTT, optimization was performed based on static analysis and the boundary conditions, so three prototypes were designed. A comparison of the proposed trolley with the conventional one under the same conditions revealed an up to 71.04% decrease in volume while the yield-strength reached 8.67 to 11.43%. In conclusion, the optimal trolley proposed was found to be reliable in terms of economy and stability.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.10a
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• pp.717-718
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• 2012

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.1
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• pp.37-44
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• 2001

This paper describes the position control method in yard crane drive system using Lonworks network, which is a leading industrial control network. The network is composed of host computer and three motor drive systems for both gantry and trolley position controls of both gantry and trolley are controlled with the simulator of yard crane, the size of which is about 1/10 with the real yard crane.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.10a
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• pp.561-562
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• 2006

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1622-1625
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• 2003

RMQC, rail mounted quay crane, lifts and moves large container by means of hoist and trolley motion on the dock. Our company is trying to develop advanced RMQC applying the concepts of elevator hoist and container conveyer for the automation and high efficiency in handling the boxes. Prior to the development of new products, it is necessary to check the capacity of conventional crane for reference. The program simulates container-handling rates and gives some design factors for the conventional cranes.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1109-1113
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• 2004

RMQC, rail mounted quay crane, lifts and moves large container by means of hoist and trolley motion on the dock. Our company is trying to develop advanced RMQC applying the concepts of elevator hoist and container conveyer for the automation and high efficiency in handling the boxes. Prior to the development of new products, it is necessary to check the capacity of the new systems using simulation program. The program simulates container-handling rates and gives some design factors for the new-type cranes.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1991.10a
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• pp.111-114
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• 1991

The KMRR 4-wheel crane which has a span of 30.6m long shall be designed to maintain its structural integrity during and after seismic shocks. Horizontal and vertical FRS for OBE and SSE conditions at the crane support are after seismic shock. Horizontal and vertical FRS for analysis are 4% for OBE and 7% for SSE. The crane consists of girder, saddle main and auxiliary trolley, and necessaries. They are modeled as beam elements and lumped masses for the following 4 cases ; trolley at center of the crane with and without the rated load, trolley at end with and without the rated load. The static analysis as well as the linear dynamic analysis including frequency and response spectrum analysis are performed for the seismic qualification of the crane using the Finite Element Method. For the simplicity of the analysis, the decoupling criteria are considered for the crane rope and the crane supporting beams. The main sections of the crane are stiffened until the calculated stresses satisfy the allowable limits. The seismic resultant loads are used to design the seismic restraints of the saddle and the trolley to protect the clue from the seismic uplifting loads the study results have show that the seismic design of the KMRR crane is governed by the OBE condition. not by the SSE condition. This paper briefly describes the analysis procedure used in the seismic design of the KMRR crane, and summarizes the analysis results.