• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.108-112
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• 2002

A new pixel driving method for organic light-emitting diode (OLED) flat-panel display (FPD) is proposed. The new charge-pump passive-matrix pixel driver consists only of a storage capacitance and a rectifying diode, and no thin-film transistor (TFT) is needed. The new driver not only supplies a constant current to the OLED throughout the whole period of panel scanning like an active-matrix driver, but also provides a highly linear gray-scale control through a pure digital manner.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.665-672
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• 2004

Chemical cleaning of boiler pipelines is necessary before the commissioning of thermal power plant after many years of construction. Fluid-Dynamic study for the chemical cleaning of boiler piplelines in Young-Heung thermal power plant is carried out. First, flow velocity necessary to sustain and exhaust solid particles in the vertical pipelines is calculated. Second, the flowrate necessary to make the calculated velocities in each vertical pipelines is calculated. Third, all the pipelines are analyzed with the Piping Systems Fluid Flow software to calculated the pressure loss in the pipelines. Finally, the operating point of the applied pump is calculated with the help of the same software.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.3
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• pp.94-102
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• 2019

Mono pump rotors are widely used in wastewater treatment plants, medicine, cosmetics, paint, paper, and chemical manufacturing, dairy production, public works, agriculture, and so on. A mono pump comprises two main parts: the rotor and stator. Typically, the rotor is machined using an expensive whirling machine. In this study, we developed an algorithm for 4-axis machining of the rotor on machining center (MCT). NC-code was obtained by applying the algorithm and finally the rotor of the mono pump was machined on a 4-axis MCT. Results of four sample experimental works showed close agreement with design geometries.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.22 no.5
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• pp.325-340
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• 1993

• Journal of the Korean Society of Industry Convergence
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• v.8 no.4
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• pp.191-196
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• 2005

This study was carried out to investigate the heat storage/release characteristics of the thermochemical reaction of the calcined dolomite with the packed bed shape experimental apparatus for development of chemical heat pump system. In the present study, it was found that MgO of the calcined dolomite was not hydrated during the hydration process under the experimental conditions. Therefore, the MgO of the calcined dolomite can be regard as an inert material. As a result, it was found that all of CaO packed kept the reaction temperature of about $510^{\circ}C$ through the entire part of the bed. The dehydration reaction was incurred first at the wall side area as the supplied heat was transferred through the wall side into the packed bed. As a result of the temperature and concentration spread, the reaction was completed at the wall side progressed into the center.

• Clean Technology
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• v.7 no.2
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• pp.151-159
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• 2001

Mathematical modeling and numerical simulation studies have been conducted for a falling film type absorber of the ammonia absorption heat pump. A rigorous absorber model has been developed by considering temperature effects on physical properties and its predictability proved far superior to that of existing models, which has been confirmed by the experimental data. Using the developed model, effects of cooling water condition - temperature and flow rate - on the efficiency of absorber has been examined. As the result of simulation, the efficiency of absorber has increased as the cooling water temperature has decreased and flow rate has increased.

• Journal of the Korean Society for Precision Engineering
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• v.34 no.2
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• pp.101-106
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• 2017

The chemical mechanical planarization (CMP) process combines the chemical effect of slurry with the mechanical effect of abrasive (slurry)-wafer-pads The slurry delivery system has a notable effect on polishing results, because the slurry distribution is changed by the supply method. Thus, the investigation of slurry pumps and nozzles with regard to the slurry delivery system becomes important. This paper investigated the effect of a centrifugal slurry pump on a spray nozzle system in terms of uniform slurry supply under a rotating copper (Cu) wafer, based on experimental results and computational fluid dynamics (CFD). In conventional tools, the slurry is unevenly and discontinuously supplied to the pad, due to a pulsed flow caused by the peristaltic pump and distributed in a narrow area by the tube nozzle. Adopting the proposed slurry delivery system provides a higher uniformity and lowered shear stress than usual methods. Therefore, the newly developed slurry delivery system can improve the CMP performance.

• Journal of Surface Science and Engineering
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• v.51 no.4
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• pp.218-223
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• 2018

In this study, we proposed a new ultrasonic-chemical decontamination process for decontaminating radioactive corrosion products during the maintenance of reactor coolant pump (RCP). The actual decontamination process was reproduced in the laboratory. And the corrosion characteristics of stainless steel (STS), constituting the RCP interior parts, were examined. The weight-loss measurment and polarization experiment were carried out in order to determine the corrosion characteristics of STS 304 and STS 415 by repeated decontamination processes. The STS 304 presented a little corrosion damage, which was almost indistinguishable from visual observation. The weight-loss rate of STS 304 was also significantly lower. On the other hand, STS 415 showed severe corrosion damage on its surface, greater weight-loss rate and higher corrosion current density than STS 304.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.12
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• pp.1192-1203
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• 2005

A technical analysis was conducted to predict the development trend for heat pump system. The study was based on a submitted patent from 1983 to 2002 in Korea, U.S.A. and Japan. The total number of raw data from the registered database was 19,261 and the obtained data to be analyzed through the filtering process was 5,143. Technical development of compression type heat pump was more dominant than the other types, absorption, adsorption, and chemical heat pump. The patents for compression type made up over $80\%$ in each country, Most of patents were developed for the defrosting and controlling technology of the compression type heat pump system. Approximately $24\%\;and\;62\%$ of the patents about compression type heat pump were for defrosting and control technologies, respectively.

• Proceedings of the PSK Conference
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• 2000.10a
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• pp.271.1-271.1
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• 2000