• Proceedings of the KIEE Conference
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• 2005.05b
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• pp.62-63
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• 2005

Recently, sectionalizing switches have been coming to be operated by remote control through the distribution SCADA system. However, the problem of determining the optimal switching sequence is a combinatorial optimization problem, and is quite difficult to solve, Hence, it is imperative to develop practically applicable solution algorithms create a new arbitral distribution system configuration from an initial configuration, and some of these algorithms do not show a load transfer sequence to reach the objective system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.11a
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• pp.381-383
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• 2004

Recently, sectionalizing switches have been coming to be operated by remote control through the distribution SCADA system. However, the problem of determining the optimal switching sequence is a combinatorial optimization problem, and is quite difficult to solve. Hence, it is imperative to develop practically applicable solution algorithms create a new arbitral distribution system configuration from an initial configuration, and some of these algorithms do not show a load transfer sequence to reach the objective system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.418-420
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• 2005

Recently, sectionalizing switches have been coming to be operated by remote control through the distribution SCADA system. However, the problem of determining the optimal switching sequence is a combinatorial optimization problem, and is quite difficult In solve. Hence, it is imperative to develop practically applicable solution algorithms create a new arbitral distribution system configuration from an initial configuration and some of these algorithms do not show a load transfer sequence to reach the objective system.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2000.04a
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• pp.268-271
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• 2000

Based on the rapid development of information technology (IT) including networks, manufacturing environment faces more customer engagement, global collaboration, greater emphasis on agility, increasing reach and connectivity through world-wide web, and micro transaction tracking and intelligence to name a few. The new ideas of manufacturing concept, eManufacturing is discussed in view of IT. In specific, a framework to identify. IT application in the product realization process and collaboration and coordination to implement eManufacturing is proposed.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.669-679
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• 2003

Through AIS(Automatic Identification System), ITU-R suggested the navigational data communication between ships and between ships and shore stations for the better safety of navigation, and it requires two different the transmitting output power level depending on its operating mode. According to ITU's recommendation, these levels should reach within 20% of its final value in 1ms. In this paper, an adequate feedback control circuit for power amplifier module is designed and implemented.

• Journal of Ginseng Research
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• v.17 no.3
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• pp.236-239
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• 1993

We studied the chloroplast rearrangement, short-term regulation depending on the light conditions in plants, and the characteristic of photosynthic rate as affected by in Panax ginseng C.A. Meyer. The chloroplast rearrangement of ginseng mesophyll cell was induced with the irradiation of blue light (400~500 nm) and through this process the rate of leaf transmittance increased 5~7.5%. The time to reach the maximum value of photosynthesis was shorter above 20 minutes with the blue light irradiation than that of the red light.

• Water for future
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• v.17 no.2
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• pp.85-97
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• 1984

Measuring the river flow and water quality in the midstream of the Nakdong River, the natural purification status in examined through the analyses of the elements which affect the variation of dissolved oxygen, and DO model is evaluated to the midstream reach of the river. The major results of this study are as follows; the pruification factor of the of the river is relatively high, it is worried over eutrophication considering much production of algae, and it is evaluated that important factor affecting the DO value computed by the proposed DO model are in order of reaeration coefficient, carbonaceous BOD and deoxygenation constant.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.2
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• pp.239-243
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• 2008

The fluctuation of inlet flow to a water treatment plant makes a serious problem that it can change the outlet flow-rate from each process abruptly, and ultimately occur the detachment of the attached particles inside each unit process. Also, since it takes very short time for the surface wave occurred from the fluctuation of inlet flow to reach the latter processes, it is impossible for operators to cope with that stably. Therefore this study was conducted to suggest the methodology for accurately predicting the travel time of surface wave occurred from the fluctuation of inlet flow to reach the latter process. Through the experiment, which was carried out for the full-scale water treatment plants(capacity : 2,000m3/d), it could be confirmed that the flow rate fluctuation from equalization tank produce the surface wave. And the wave transfer velocity is a function of the hydraulic radius and the length of each open type tanks which are comprised in the latter processes.

• Journal of Wetlands Research
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• v.3 no.2
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• pp.119-131
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• 2001

This study uses HEC-RAS for the quantitative aspects and the QUAL2E model for the qualitative aspects of the flow of urban streams, where the natural recovery system is applied. The instream flow of the small streams is estimated using the numerical model by verifying the existing data with the acquired data. The characteristics of the model reach place more weight on the drought discharge around the ordinary discharge, and this is caused by the natural recovery system that maintains the existing bank. The data of direct discharge to the sewage treatment plant through the inception pipe, BOD, DO, temperature, and so forth, are the official data from the department of environment. Considering the characteristics of small streams, the factors for the QUAL2E model are estimated with the focus on the hydraulic conditions and the stream view. This study proposes the future improvements for the natural recovery system by investigating the practical use of the waterfront and the application of the proper instream flow. Also, the hydraulic and hydrological investigation of the covering rate by the natural vegetation and the meandering by the varying river way is performed.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.2
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• pp.280-288
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• 2003

We need refrigeration system which can maintain the freshness of agricultural products, because of being distance from a tiller to a consumer. Vacuum Pre-cooling system has an advantage in quality maintenance through vapid cooling down by using latent heat of evaporation of stored products. A number or thawing methods in current use have also several disadvantages in thawing time. discoloration mass loss caused by drying, capital costs and running cost. These damages are, it is claimed, either eliminated or improved by the vacuum thawing system. An experimental study on the pre-cooling for the bean sprouts and cabbage, and thawing for hairtail and croaker by the low temperature vacuum system were carried out. The cabbage cooling time with this Pre-cooling vacuum system took about 60 minutes to reach from $23.2^{circ}C to 4.5^{\circ}C$ at 5 mmHg abs. ($6.66\times10^{-4}$ MPa). The croaker thawing time with this low temperature vacuum thawing system took about 170 minutes to reach from $-10.3^{circ}C to -0.8^{\circ}C$ at 20 mmHg abs ($2.67\tiems10^{-3}$MPa). The vacuum Pre-cooling and thawing system have merits compared with present systems in their short intervals to cool down and to thaw without any quality losses.