• Journal of Advanced Marine Engineering and Technology
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• v.15 no.5
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• pp.38-46
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• 1991

In the design of an electric power plant, the capacity to meet the peak load demand is one of the important factors to be considered. This peak load usually occurs when the most of the cooling air-conditioning systems are being operated during daytime in summer season. Therefore, it is necessary to construct an additional electric power plant and to develop the new air-conditioning system for relieving the peak load. This paper analysed the performance characteristics of this experimental regenerative ice energy system by means of a bundle of the heat-pipes. And the result of this analysis was applied to the simulation of an air-conditioning system model. Also, an operation program of moisture air was made according to air load and in order to computerize the air-conditioning system a CAD program was developed by the properties of moisture air.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.1
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• pp.104-113
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• 2002

An accumulator in hydraulic systems stores kinetic energy during braking action and then that controls hasty surge pressure. An energy recovery system using accumulator seems to be advantageous far ERBS due to its high energy density. This study suggests a method to decide suitable accumulator volume far ERBS. The method is based upon energy conservation between kinetic energy of moving inertia and elastic energy of accumulator. The energy conversion was analyzed and a simple formula was derived. A series of computer simulation was done to verify effectiveness of the formu1a. The results of the simulation work were compared with those of experiments and these results show that the proposed design is effective far decision of accumulator volume in ERBS.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.623-628
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• 2009

Desiccant based air conditioning system offers a promising alternative to conventional one using vapour compression refrigeration for energy saving and greenhouse gas reduction. It is a heat driven cycle which has high potential for the use of low grade heat source such as the waste heat from the cogeneration plant or the solar thermal energy. In this study, the cooling performance of a desiccant cooling system incorporating a regenerative evaporative cooler was characterized in various operation conditions through numerical simulation. The cooling capacity and COP were evaluated at various outdoor conditions, regeneration temperatures, and supply flow rates. Based on the performance characteristics, the optimal control scheme was discussed to minimize the cooling cost at part load condition.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.1 no.1
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• pp.1-8
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• 1989

This paper treats the temperature effectiveness of the two-fluid counterflow regenerator in a rotary type. To avoid continual interpolation and to obtain the simple result in calculating that, it obtained the particular solution for the direct-transfer-type counterflow heat exchanger by the graphical procedures. Also, it introduced the empirical formula for the influence of the ratio of rotor matrix to minimum working fluid heat capacity rate with the particular solution induced. Particularly, substituting the published results of temperature effectiveness into the program, it obtained the simple and convenient equation which can applicate in the counterflow regenerator in a rotary type. To compare and discuss the results induced, selecting the regenerative air preheater and applying the their running datum and specifications to the related results, it shows that the above results are agree with the published results within absolute relative error, 3.0%.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.34 no.3
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• pp.115-123
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• 1985

A two phase chopper system with two separate groups of DC motors for regenerative braking is dealt with in this article. The main circuit consists of two sets of chopping parts, four diodes and two separate groups of DC motors. Although the proposed chopper circuit requires more circuit elements than the conventional two phase chopper system with combined output, it has the following advantages`(1). Ripple frequency of smoothing reactor current becomes twice as high as that of the conventional system, so the continuous current range and the ripple ratio are improved greatly. Therefore, the efficiency becomes even higher, the capacity of commutation equipment is reduced and the inductive interference become less.(2). Load current division becomes equalized. Therefore it is possible to drive not only series motors but also shunt, separately excited and compound motors.

• Natural Product Sciences
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• v.28 no.3
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• pp.105-114
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• 2022

Tinospora crispa (L.) is a medicinal plant traditionally used to treat various ailments including diabetes. The stem has been widely studied for its antidiabetic properties, however the antidiabetic potential of its leaves has not been explored. This study investigates the antidiabetic properties of methanolic T. crispa stem and leaves extracts on alloxan-induced diabetic rats. The stems and leaves were extracted using Soxhlet extraction with methanol as solvent. Crude extracts were administered at 500 mg/kg body weight (BW) (high dose) and 250 mg/kg BW (low dose) via oral route to alloxan induced diabetic rats. T. crispa stem and leaves extracts was found to significantly reduce blood glucose following a twelve-week treatment period. The highest mean difference in blood glucose level was exhibited by animals in the high dose treated stem and low dose leaf extracts. Both extracts showed approximately 75% percentage recovery from hyperglycaemia. The highest regenerative capacity was observed in animals treated with the low dose leaf extract.

• Journal of Periodontal and Implant Science
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• v.38 no.4
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• pp.621-628
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• 2008

Purpose: Osteopontin is one of the major non-collagenous protein of hard tissue. Use of peptide domain of biologically active protein has some advantages. The objective of this experimental study is evaluation of periodontal regenerative potency of synthetic peptide gel which containing collagen binding domain of osteopontin in the degree III periodontal defect of beagle dogs. Material and Methods: Experimental degree III furcation defect was made in the mandibular third and fourth premolar of beagles. Regenerative material was applied during flap operation. 8 weeks after regenerative surgery, all animals were sacrificed and histomorphometric measurement was performed to calculate the linear percentage of the new cementum formation and the volume percentage of new bone formation. Result: The linear percent of new cementum formation was 41.6% at control group and 67.1% at test group and there was statistically significant difference. The volume percent of new bone formation was 52.1% at control group and 58.9% at test group. Conclusion: As the results of present experiment, synthetic peptide gel containing collagen binding domain of osteopontin significantly increase new bone and cementum formation in the degree III furcation defect of canine mandible.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1159-1163
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• 2014

This paper have been dealt with the analysis for energy efficiency improvement effect of unity storage capacity as a part of the energy storage application study to improve energy efficiency in the electric railway systems. Especially, in order to estimate the amount of energy saving according to the variation of power capacity of each storage, the current limit module was mounted on an existing DC electric railway loadflow program which is based on the analysis model for railway system and storages, and combined optimization algorithm to determine optimal voltage boundary.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.697-700
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• 2007

Six thousands of vehicles are operated on Korean urban transit system. 95% of them have regeneration system. Especially, the VVVF-Inverter vehicle has a merit of the highest regeneration rate. Therefore, the energy storage system is needed to be developed to use regeneration energy when the vehicle is braking. Therefore, Measuring regeneration energy in the substation need to know how much regeneration energy occurs, how much capacity of energy storage system is needed. After measuring regeneration energy, we design the capacity of energy storage system.

• Proceedings of the KIPE Conference
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• 2014.11a
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• pp.75-76
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• 2014

This study deals with a isolation type MIC(Module Integrated Converter) for AC module with advantages such as DC Wireless, freely selectable installation capacity, minimized shadow effect etc. In this paper, MIC circuit with the function which can remove the ripple voltage of PV module and give the discharging path for charged energy in leakage inductance of isolation transformer. The validity of proposed circuir is verified by the simulation with PSIM.