• Journal of Electrical Engineering and Technology
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• v.1 no.1
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• pp.28-34
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• 2006

Recently, in accordance with the development of IT technology, it is prevalent for power quality monitors to be connected to each other via networks and share their data because such networks provide system-wide insights to customers concerning power quality. Those systems can alarm and display power quality events for the convenience of customers. However, if a power quality event occurs, it is difficult for customers to determine its cause and solution because the systems do not provide appropriate power quality diagnosis functions. The power quality management system presented in this paper has been developed to provide customers with various power quality diagnosis functions so that they can cope well with power quality problems with the right measure in the right place. This paper presents the structure and functions of the developed power quality management system and shows some results of the power diagnosis functions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7761-7772
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• 2015

This study describes the spatio-temporal distributions in phytoplankton community such as species composition, standing crops and dominant species from April to November 2008 in the Jeju Marine Ranching Area (JMRA). A total of 106 species of phytoplankton belonging to 63 genera was identified. In particular, diatoms and dinoflagellates were occupied more than 61% and 35% of total species, respectively. The annual dominant species were Skeletonema costatum-like species(ls) in April, Torodinium teredo, Cylindrotheca closterium, Scrippsiella trochoidea in June, S. costatum - ls, Thalassionema nitzschioides, Pseudo-nitzschia pungens, Ebria tripartita in September and Corethron pennatum, Dictyocha fibura, Neoceratium teres in November. Phytoplankton cell density ranged between $0.6cells{\cdot}mL^{-1}$ in June and $64.0cells{\cdot}mL^{-1}$ in April. It fluctuated with an annual mean of $11.7cells{\cdot}mL^{-1}$ between the lowest value of $0.9cells{\cdot}mL^{-1}$ in November and the highest value of $37.0cells{\cdot}mL^{-1}$ by S. costatum -ls in April. Diversity index in September was higher than diatom blooming seasons in April. According to the phytoplankton community structure, the biological oceanographic characteristics of the JMRA was characterized by nanoplankton during a year. That is, primary production is deemed to have a higher possibility of being adjusted by a reproduction by material cycle in the ecosystems than nutrients supply from the lands.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.188-198
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• 2015

This study was conducted in order to investigate the distribution pattern of weeds and ecological characteristics on the dry field in the Eastern region of Korea. The weed species data were obtained from 12 regions in Gangwon-do and Gyeongsang-do. 150 taxa were recorded from three main distinguished habitats; inside of dry field (IDF), embankment around the end of dry field (EDF), levee slope of dry field (LS). The weed species of three different habitats were IDF 83 taxa, EDF 133 taxa and LS 105 taxa. The species showing higher rNCD value was Portulaca oleracea in IDF, Digitaria sanguinalis in EDF and Humulus japonicus in LS. Compositae was dominant family followed by Gramineae, Polygonaceae and Leguminosae. Life form was distinguished as Th-R5-D4-e and three different habitats showed the same results. Disturbance index was analysed as IDF 83.1%, EDF 68.4%, and LS 62.9%. Naturalized rate was analysed as IDF 28.9%, EDF 22.6%, and LS 20.0%. These results indicate that the weeding management, land use intensity, and human interference effect on the distribution index and naturalized rate of weed.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.77_78
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• 2009

한국형 에너지 관리 시스템 (이하 K-EMS)의 운영에 있어 현장 데이터 취득은 EMS의 기본 기능이라 할 수 있는 SCADA의 중요 요소이다. 특히 단일 통신 회선으로 구성된 K-EMS의 구조적 특성으로 인해 RTU 통신 회선의 단절은 주요 EMS Application의 운영에 영향을 미칠 수 있으므로, 예비회선 역할을 할 수 있는 데이터 Path를 확보하는 것은 이중화된 통신 회선을 갖는 것과 동일한 효과를 가질 수 있다. 이에 센터 간(Local, Remote1 and Remote2) FEP(Front End Processor)를 통해 RTU 데이터를 교환하는 데이터링크 시스템을 개발하였다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.290-292
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• 2002

In this paper, we present a simple design method and measurement results for circular loop antenna arrays, which can be used for LS band operation, such as access point antennas in the wireless LAN system. It has been shown that the input impedance of a circular loop can be adjusted near 100 $\Omega$ using a short stub. The length of the stub can be immediately determined in the work place through the measurement of S11 with a network analyzer. Fabricated arrays show high antenna gains as much as 12.4㏈i and 15.1 ㏈i at the center frequency of 2.45 ㎓ for 4${\times}$l and 4${\times}$2 array, respectively. These types of loop arrays can be fabricated at a low cost.

• Proceedings of the KOSOMBE Conference
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• v.1989 no.05
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• pp.45-49
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• 1989

In this paper the feature of background EEG is extracted by LS Prony Method for the analysis of background EEG in the time domain. From the experimential results the alpha band amplitude is the largest among bands and beta band amplitude is larger than that of the delta band and theta band. The sustained time for the alpha band, the beta band, the delta band and the theta band is 2.3461(sec), 1.8980(sec), 0.3120(sec), 0.2930(sec) respectively. Consequently the alpha band and the beta band are maintained in the whole, segment. The delta band, the theta band are existed intermittently in the segment.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.1
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• pp.55-59
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• 2016

In Europe, polypropylene-insulated HV class cable with high temperature and no cross-linking was commercialized following the MV class. Our company also started a study of the polypropylene-insulated cable in 2013 and was carried out thermal, physical and electrical test. In addition, polypropylene-insulated cable was tested for compatibility with conventional joints and terminations in emergency condition and the accelerated life test for verifying their design life is in progress. The results of this study will be used to establish a standard specification and operation conditions of the polypropylene-insulated cable.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1210-1212
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• 2005

High temperature superconducting(HTS) power cable system consists of HTS cable, termination and cryogenic system. And the HTS cable consists of the former, HTS phase conductor, electric insulation, HTS shield and cryostat. Taking the advantage of HTS shield, the cold dielectric has been adopted. The phase conductor and the shield have been designed to minimize the AC loss below 1W/m/phase. The former has been designed to transport the fault current of 25kA, at fault condition. This paper describes the design process of 22.9kV HTS cable considering AC losses at normal state and the stability at fault condition.

• Journal of the Korean Society of Radiology
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• v.17 no.7
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• pp.1149-1155
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• 2023

This study aims to investigate the effect of changes in the Sub ROI on exposure index(EI) and to present indicators of changes in EI values that may occur when changing Sub ROI in clinical practice. This study was conducted on a subject of 20 cm of acrylic for a setting similar to abdominal radiography, and the specifications of one acrylic sheet is 20 × 20 × 5 cm. The survey conditions were the same as 80 kVp , 320 mA, 25 ms, SID 110 cm and the Sub ROI obtained 30 images for each type using five types provided by the equipment company. The EI value provided by the equipment and entrance skin exposure(ESE) were compared and analyzed. The mean value of EI according to the change in Sub ROI was 101.18±0.27 for LS, 106.57±0.31 for AEC, 107.74±0.39 for VR, 107.90±0.38 for HR, and 109.72±0.32 for SS (p<0.01). The average value of ESE by sub ROI type (LS, AEC, VR, HR, SS) was measured to be 476.45±1.71 μGy, 476.92±1.48 μGy, 476.14±2.30 μGy, 475.61±1.96 μGy, and 477.14±1.46 μGy, with statistically significant differences (p<0.01). As a result of this study, the EI according to the sub ROI type is based on LS(109.72), which represents the minimum value. AEC increased 5.3%, VR increased 6.4%, HR increased 6.6%, SS increased 8.4%, and overall, increased by about 5.3%. As for the average value of ESE, HR(475.61 μGy)type showed the minimum value, and based on this, AEC increased 0.27%, VR increased 0.11%, LS increased 0.17%, SS increased 0.32%, and overall, increased by about 0.17%.

• Journal of Plant Biology
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• v.35 no.3
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• pp.237-245
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• 1992

To understand the properties of the cauliflower mosaic virus (CaMV) 35S promoter and the effect of the deleted maize alcohol dehydrogenase I-S (Adhl-S) intron 1 on the expression of the CaMV $35S{\beta}-glucuronidase$ (GUS) gene in potato (Solanum tuberosum L. cv. Superior), we constructed a chimeric gene and transferred it into potato with Agrobacterium tumefaciens mediated method. The pLS201, a gene transfer vector of 17.7 kilobase pairs, was composed of the CaMV 35S promoter, the 249 base pairs of deleted maize Adhl-S intron 1, the GUS reporter gene, and the kanamycin resistance gene as a selectable marker for transformation. The GUS activity was examined by histochemical and spectrophotometric assay in transformed potato plants. The GUS activity was found primarily around the vascular tissue cells in stem and root. In the spectorophotometric assay, the level of GUS activity of transgenic potato transformed with CaMV 35S/249 bp of intron 1 fragment-GUS (pLS201) was compared with that of potato transformed with CaMV 35S-GUS (pBI121). The quantitative spectrophotometric assay showed that the level of GUS activity in potato transformed with pLS201 was higher in leaf, stem and root by 30-, 34- and 42-fold, respectively than those in potato transformed with pBI121. This results indicate that the inclusion of the deleted maize Adhl-S intron 1 resulted in increament of the GUS gene expression in transgenic potato.potato.