• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.5
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• pp.493-500
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• 2000

The battery charger for high speed trail car is very important power source for the purpose of safety and system stability It provides control power of VVVF, CVCF, DC/DC converter and inverter for traction motor. This paper included power circuit of the ZVZCS type battery charger for high speed trail car and battery charging algorithm. Also the optimum parallel operation of 50kW battery charger for high speed trail car, and charring control method of Ni-Cd battery illustrates validity and effectiveness through the experiments.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.268-271
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• 1993

Discharge pumped high power excimer laser is a very useful light source of ultraviolet region. In this paper. the design and operation characteristics of UV pre-ionized discharge pumped XeCl laser are discussed. Maximum output power of 890mJ at the efficiency of 1.4% was achieved with 35kV charging voltage, 3.4atm of total pressure and 10pps of pulse repetition rate. Optimum HCl pressure is considered to be between 2.5 and 3.5torr.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.04a
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• pp.1020-1024
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• 1997

Recently the use of ceramic materals has been greatly increased in the industries. But machining of the ceramics is quite unproductive because of their high stength,high hardness,and brittleness. The efficiency of the grinding operation of ceramics depends on the preparation of diamond grinding wheel, i.e.,truning and dressing. This paper describes some experimental results on the dressing conditions of diamond grinding wheel. The dressing performance is evaluated by the magnitude of normal grinding force. The better dressed wheels result in the lower normal grinding forces. The dressing performances of copper plate and aluminum oxide dressing stick are compared. The optimum dressing conditions including the grit size of dressing sticks, the depth of the dressing operation, and the dressing speed qre determined.

• Journal of Animal Environmental Science
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• v.4 no.2
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• pp.113-126
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• 1998

This study was conducted to develop pig-housings based on the forecasting models of swine production, the weather conditions, and so on in Korea. The Korean pig-housings were developed according to the following basis : 1. They should be suitable to domestic weather conditions. 2. They should be designed based on the forecasting models of swine production of farrow to finish operation among the forecasting models of swine production in Korea. 3. Proper environments should be offered to pigs according to the growth. 4. The environmental control, the treatment of swine wastewater, and so on should be interrelated. 5. Manual energy should be saved by effective arrangements of pig-housings. In the future, performance test of the Korean pig-housings and development of facility automation systems which are suitable to these should be accomplished.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.816-822
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• 2010

A comprehensive review for the selection of urban rail vehicle systems that best suit Gimpo railway line is taking place with consideration of the project area characteristics in light of line planning, passenger demand, supply of rolling stock, and railway construction and operation. Various aspects of vehicle systems including passenger demand on concerned lines, regional characteristics, vehicle types, and railway construction and operational settings should be taken into consideration. In addition, request for the introduction of customized vehicle systems reflecting the convenience of transit users such as wide and hospitable inner space, low noise, flexible operation of 2 to 4 car train-set and eye catching slim bridge piers is increasing. A study on alternatives to place an order to opt for optimum rolling stock systems considering line characteristics of Gimpo City's urban railway and future passenger demand while meeting the needs of Gimpo City has been conducted.

• Journal of the Korean Institute of Telematics and Electronics
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• v.17 no.6
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• pp.72-77
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• 1980

We analyze several problems concerning the operation of the optical feedback prebias control scheme in the loser diode optical transmitter and present a LD simulation circuit as a way of adjusting the component's optimum value without using the Laser - triode. 1.5% light power decrease was observed between the temperature range of $0^{\circ}C$ and 36$^{\circ}C$ in which the total light power of LD was used for feedback loop and fairly good operation was demonstrated when a star coupler was employed as a beamsplitter by which approximately 1% portion of the light power was feedbacked.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.3
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• pp.63-73
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• 1993

In this paper, fuzzy control algorithm for the speed ratio control of the electro-hydraulic rig type continuously variable transmission(CVT) was proposed and the CVT performance tests were carried out for the optimal operation of the engine simulator. The experimental results for the constant throttle and the acceleration modes showed that the engine can be run on the optimum operating line, representing the power and economy mode, by the fuzzy control of the CVT speed ratio. Comparing the PID control with the fuzzy control, it was found that the fuzzy control showed better performance with the faster rising time and smaller steady state error. The result of this study can be used as basic design materials for developing the transmission control unit of the CVT.

• Journal of Welding and Joining
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• v.28 no.5
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• pp.58-63
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• 2010

The purpose of this study is to develop improved boom structures with reliable fatigue strength of weldment and lower production cost. For that purpose, multibody dynamic analysis was performed to evaluate forces acting on arm & boom cylinders and joints of boom structure during operation of an excavator for three working postures, then stress analysis was made to investigate stress distribution around diaphragms at the bottom plate of boom structures which was known to be susceptible to fatigue failures of welded joints, and finally boom structure with optimum arrangement of diaphragms was proposed. This work basically consists of the following two parts: part 1 focuses on multibody dynamic analysis of excavators during operation and part 2 includes evaluations of fatigue strength of welded joints for modified boom structures.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.4
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• pp.410-415
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• 2011

A cylindrical type of self-controlled restrictor is designed for hydrostatic bearing of crank shaft for a grinding wheel spindle. The effect of operation parameters, clearance between spindle and housing on bearing stiffness are analyzed to determine the optimum conditions of operation parameters. The lowest values of the supply pressure and the loads by the theoretical and experimental results assuming oil film thickness and shape of pocket are compared.

• Journal of Korean Society for Quality Management
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• v.36 no.1
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• pp.40-48
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• 2008

The purpose of this study is to rationally manage service facilities of convention center. This study is to develop the algorithm to consider optimal assignment and optimal operation system planning for convention center. The scheduling algorithm of this study develops through constructing the mathematical model and analyzing the mathematical structure of variables and constraints in model. The scheduling algorithm develops to consist eight stage of optimal operation planning and five stage of optimal assignment planning. Especially, this study indicates that optimum answer through mathematical model and results of algorithm is nondiscrimination.