• Proceedings of the Membrane Society of Korea Conference
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• 1992.04a
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• pp.11-28
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• 1992

In this paper we will first give a short overview of the more recent developments in MF, UF and RO. This is followed by a closer look on newer technologies applied in environmental problems. The applications looked an are the recovery of organic components from solvent laden gas streams and the separation of organic volatiles from aqueous waste waters via pervaporation. Technical solutions, the advantages and disadvantages of the processes and, where possible, cost estimations will be presented.

• Journal of Electrical Engineering and Technology
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• v.6 no.1
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• pp.86-93
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• 2011

To minimize the cost and power consumption of PDP TV, a practical sustain circuit topology is presented with an address-and-display-period-separated driving scheme. The proposed sustain driver employs bidirectional switches to reduce the number of components. Operational principles and corresponding features are illustrated and compared with the conventional approach. The valuable contributions of the proposed high-performing sustainer has been proven by computer-aided simulations and experiments by using a prototype equipped with 7.5-inch diagonal panel operated at 200 kHz switching frequency.

• Journal of Power Electronics
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• v.9 no.6
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• pp.892-902
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• 2009

This paper deals with the dynamic voltage control problem at the inverter end of a HVDC link when connected to a weak AC system which has the potential for harmonic instability and commutation failures. The dynamic voltage control problem is tackled with a STATCOM (Static Compensator), which not only provides a rapid recovery from harmonic instability and commutation failures but also offers a lower cost filter design for HVDC systems. PSCAD/EMTDC simulations are presented to validate the proposed topology and to demonstrate its robust performance.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1551-1554
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• 2008

In this paper, some important driving issues pertaining to the sustain-driving circuit are examined A new driving circuit is also proposed The new circuit is cost effective and has a simple PCB layout in comparison to the conventional one. Some additional driving advantages are noted as well.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.489-490
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• 2010

A novel soft-switching two-switch flyback converter is proposed in this paper. This converter is composed of two active power switches, a flyback transformer, and two passive regenerative clamping circuits.The proposed converter has the advantages of a low cost circuit configuration, a simple control scheme, a high efficiency, and a wide operating range. The circuit topology and experimental results of the new flyback converter are presented.

• International Journal of Safety
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• v.3 no.1
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• pp.15-19
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• 2004

A new tower internal, which is called CSE, is presented. The CSE is composed of a nozzle perforated in its bottom along the entire periphery and equipped with a multi vane axial swirler at the inlet and hollow cylindrical separator at the outlet of the nozzle. According to the experimental work for obtaining the necessary hydraulic information of the CSE, which is used for preliminary design of a separation column, the CSE showed a stable operation over the wide rage of gas/liquid ratio. However, it caused large pressure drop due to the high gas velocity which should carry liquid droplets through the element. The high pressure drop may cause problems in energy recovery and the application of the CSE can be limited to the high pressure columns. Assuming that the tray efficiency of the CSE is the same with the existing separation columns, the results of the column design showed the size reduction of the column diameters by 30 to $40\%$ and investment cost saving, depending on operating conditions. The application of the CSE to separation column may also contribute to the de-bottlenecking the existing column.

• Journal of Power Electronics
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• v.13 no.5
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• pp.779-786
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• 2013

A highly efficient sustaining driver is proposed for plasma display panels (PDPs). When the PDP is charged and discharged, the proposed sustaining driver employs an address voltage source used in an addressing period. A voltage source is used for fully charging the panel to the sustaining voltage, and an initial inductor current helps the panel discharge to 0 V. The resonance between the panel and an inductor is made by shifting the voltage and current bias level when charging and discharging the panel. As a result, the proposed circuit can reduce power consumption, switching loss, heat dissipation, and production cost. Experimental results of a 42-inch PDP are provided to verify the operation and features of the proposed circuit.

• Journal of Institute of Control, Robotics and Systems
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• v.1 no.2
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• pp.119-126
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• 1995

The purpose of this study is to develop the technique of energy recovery and energy saving by using the optimization of heat exchanger network synthesis. This article proposes a new method of determining the optimal target of a heat exchanger network synthesis problem of which data feature multiple pinch points. The system separation method we suggest here is to subdivide the original system into independent subsystems with one pinch point. The optimal cost target was evaluated and the original pinch rules at each subsystem were employed. The software developed in this study was applied to the Alko prosess, which is an alcohol production process, for the synthesis of heat exchanger network. It was possible to save about 15% of the total annual cost.

• The Journal of Internal Korean Medicine
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• v.40 no.6
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• pp.1237-1247
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• 2019

Post-stroke oculomotor nerve palsy occurs more frequently than previously reported, but only a few studies of traditional Korean medicine treatments have been reported. The symptoms are severe and difficult to treat, and current treatments are high-cost, short-lasting, insufficient for shortening the therapeutic period and promoting better recovery, or involve the risk of post-operative over-correction or under-correction. Traditional Korean medicine treatments may be comparatively effective at lower cost and less harmful. Thus, we report three cases of post-stroke oculomotor nerve palsy treated with traditional Korean medicine.

• Journal of Korean Society on Water Environment
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• v.31 no.6
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• pp.625-631
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• 2015

In this study, low cost bio-flocculants, chitosan, cationic starch and Mg-sericite, were used as a flocculant to harvest freshwater microalgae, Chlorella vulgaris. Chitosan, cationic starch and Mg-sericite separated successfully >98% of C. vulgaris at following optimal parameters: 90 mg/L chitosan at pH 6-7, 70 mg/L cationic starch at pH 9-10 and 50 mg/L Mg-sericite at pH 4-5. A relatively high correlation coefficient (R²) of 0.9993 for chitosan, 0.9971 for catonic starch and 0.9924 for Mg-sericite was obtained. The investigated flocculants amount increased linearly with increasing the microalgae amount. The biopolymer, Mg-sericite, was more effective than that of other investigated flocculants. These results indicated that a bio-flocculants, chitosan, cationic starch and Mg-sericite, could prove to be an effective flocculant for economical production of microalgae biomass. In addition, Mg-sericite was more effective comparing to the other investigated flocculants.