• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.223-229
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• 2010

This study is to analyze location conditions for erosion control dams to be constructed in Chungcheongnam-do, Daejeon Metropolitan City, Chungcheongbuk-do and Gyeongsangbuk-do in order to establish proper conditions for erosion control dams in the future. 199 sites where erosion control dams are expected to be built in 2010 were chosen and investigated in terms of 12 factors including basin area, basin slope, and landslide risk. The results showed that erosion control dams for Chungcheongnam-do and Daejeon Metropolitan City are mostly impermeable gravity dams mainly composed of concrete. In contrast, Chungcheongbuk-do and Gyeongsangbuk-do are increasing the number of permeable or compound erosion control dams. Basin analysis at planned erosion control dam sites showed that at least 44.5% of the total area has high landslide risk. Gyeongsangbuk-do had the largest basin area for erosion control dam sites at 157.3ha, followed by Chungcheongbuk-do at 64.4ha and Chungcheongnam-do at 54.8ha. Analysis of sand deposits in the Chungcheongnam-do erosion control dam built in 2010 confirmed an average deposit of 971.8m3. The sand deposit capacity and amount of sediment control for erosion control dams have a very low correlation with basin area or flow path slope, and this needs to be addressed in future sand deposit capacity designs.

• Journal of Korean Society on Water Environment
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• v.29 no.1
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• pp.107-113
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• 2013

The major tributaries in Sapgyo-reservoir watershed at Chungcheongnam-do were monitored for flowrate and water quality in order to analyze the characteristics of watershed and to prepare for implementation of total maximum daily load (TMDL). According to the analytical results of flowrate and water quality monitoring data of sixteen tributaries, the tributaries with the value of flowrate over $0.5m^3/s$ were 62.5% among the monitored tributaries and the value of flowrate in the Cheonancheon, Namwoncheon, Shinyangcheon except Gokgyocheon, Muhancheon, Sapgyocheon was relatively greater than the other tributaries. However, 37.5% of the tributaries were exceeded the water quality standards of Sapgyocheon sub-basin ($BOD_5$ 5 mg/L and/or below) and the concentration of water pollutants regardless of water quality parameters in Cheonancheon, Maegokcheon, Oncheoncheon including Gokgyocheon located in Gokgyocheon catchment were relatively higher than the other tributaries. The tributaries for improving the water quality, according to stream grouping method based on the results of flowrate and water quality monitoring data, were selected. In the Sapgyo-reservoir watershed, the tributaries for improving water quality, which has a large flowrate and a high concentration of water pollutants, were selected at Cheonancheon, Gokgyocheon, Maegokcheon, Namwoncheon, Oncheoncheon. The various water quality improving plans for those tributaries, in accordance with the reduction of point source pollution by population and livestock, should be established and implemented.

• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.18-25
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• 2012

For effective watershed management, it is very important to select the tributaries through selection and concentration of targeted tributary catchments for improving water quality within the limited financial conditions. This study introduced the selection and diagnosis procedure of tributary catchments for improving water quality at Chungcheongnam-do based on water quality and flowrate monitoring, stream grouping method. The tributaries with high value of water quality and flowrate were selected for improving water quality according to stream grouping method. The diagnosis of selected tributaries for improving water quality was performed with analysis of the pollution load (generated, discharged, delivered) and point source discharged pollution load density. The plans for improving water quality of tributaries were suggested thorough various diagnosis of tributary catchments. For improving water quality of tributaries in Chungcheongnam-do, the tributary catchments in the Dangjin, Asan, Yesan, Cheonan, Hongseong area should be preferentially considered. The water quality improving plans for those tributary catchments, in accordance with the reduction of sources of pollution by population and livestock, should be established.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.286-289
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• 2002

In this paper, we use the PI dual control using do transformation(dq stationary frame and dq synchronous rotating frame) for series voltage sag and swell compensation algorithm. Analysis, simulation results are presented for voltage sags and swells on a three-phase unbalanced voltage source.

• Korean Journal of Agricultural Science
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• v.37 no.3
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• pp.515-522
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• 2010

The purpose of this research was to construct an efficient management system in developing and supplying a 'management standard diagnostic table' for the improvement of chestnut cultivation farmhouse. 'Chestnut management standard diagnostic table' were based from the actual condition of chestnut management in Chungcheongnam-do, selected 'appraisal factor item and by consulting 'agricultural plant standard diagnostic table' and various kinds of data which had already been developed. This research also consulted the classification systems and degree of importance. The developed 'Chestnut management diagnostic table' consisted of 3 first classified items, 19 second classified items and 2 product indicator items.

• Journal of Positioning, Navigation, and Timing
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• v.10 no.3
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• pp.169-177
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• 2021

In this paper, we propose a novel global navigation satellite system (GNSS) spoofing detection technique through an array antenna-based direction of arrival (DoA) estimation of satellite and spoofer. Specifically, we consider a sophisticated GNSS spoofing attack scenario where the spoofer can accurately mimic the multiple pseudo-random number (PRN) signals since the spoofer has its own GNSS receiver and knows the location of the target receiver in advance. The target GNSS receiver precisely estimates the DoA of all PRN signals using compressed sensing-based orthogonal matching pursuit (OMP) even with a small number of samples, and it performs spoofing detection from the DoA estimation results of all PRN signals. In addition, considering the initial situation of a sophisticated spoofing attack scenario, we designed the algorithm to have high spoofing detection performance regardless of the relative spoofing signal power. Therefore, we do not consider the assumption in which the power of the spoofing signal is about 3 dB greater than that of the authentic signal. Then, we introduce design parameters to get high true detection probability and low false alarm probability in tandem by considering the condition for the presence of signal sources and the proximity of the DoA between authentic signals. Through computer simulations, we compare the DoA estimation performance between the conventional signal direction estimation method and the OMP algorithm in few samples. Finally, we show in the sophisticated spoofing attack scenario that the proposed spoofing detection technique using OMP-based estimated DoA of all PRN signals outperforms the conventional spoofing detection scheme in terms of true detection and false alarm probability.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.230.1-230.1
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• 2002

In this study, anti-cancer effect of N-phenyl-O-phenylthionocarbamate (PPTC) substitutes was investigated. and the apoptotic mechanism by these substrates was examined on SK-MEL -28 human skin cancer cell line. SK-MEL -28 cell was treated at various concentrations for 48hr. and then MTT assay was performed to gain IC$\sub$50/ value and examine cytotoxicity of PPTC substitutes, and quantitative structure-activity relationship (QSAR) between cell and these PPTC substitutes was examined. (omitted)

• Proceedings of the Korean Vacuum Society Conference
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• 2008.02a
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• pp.99-99
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• 2008

• Proceedings of the Korean Vacuum Society Conference
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• 2008.02a
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• pp.101-101
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• 2008

• Proceedings of the Korean Vacuum Society Conference
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• 2008.02a
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• pp.199-199
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• 2008