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Development of the digital protection relay which displays the trip area in real time (실시간 사고영역을 표현하는 디지털 보호계전기 개발)

  • Cho, Chul-Hee;Lee, Byeong-Ho;Kim, Yoon-Hoe
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.499-500
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    • 2007
  • The existing digital protection relay is continuously growing with an improvement in technology. In this paper, we propose the development of the digital protection relay which displays the trip area in real time. In most of the digital protection relays monitor whether analog signal enters into the pre-determined trip area, but those aren't provide the trip area information for a operator in real time. Therefore, if the digital protection relay continuously displays the trip area in real time, the operator analysis power system status easily. This paper particularly introduces selective ground protective relay and differential protective relay with trip area and presents a method of providing the trip area information to operator in real time.

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Analysis of Changes in Land Use and Pollution Load for the Unit Watersheds of Total Maximum Daily Loads (총량관리 단위유역의 토지이용 변화 및 오염물질 배출형태 분석)

  • Park, Jun Dae;Oh, Seung Young;Choi, Ok Youn
    • Journal of Korean Society on Water Environment
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    • v.30 no.2
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    • pp.128-137
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    • 2014
  • The land use of the unit watersheds should be maintained appropriately in order to keep the load allotment stable for the management of Total Maximum Daily Loads (TMDLs). This study classified the land area in four types and analyzed the use of each land type and its changing pattern by calculating the occupation and conversion ratios for the unit watersheds in three river basins. The forest land showed the greatest occupation ratio with 63.0%, followed by the farm land with 23%, the other area with 8.0% and the site area with 6.0% in 2003. The occupation ratio of the site and the other area increased by 0.4% and 0.2% respectively, and that of the farm and the forest land decreased by 0.4% and 0.2% respectively in 2007. The conversion ratio for the site area ranged from 1.65% to 1.97%, for the farm land from -0.47% to -0.33%, for the forest land from -0.10% to -0.04% and for the other area from 0.17% to 1.97%. It can be inferred that the decrease in the farm and the forest land contributed to the increase in the site area and that the increase in the other area was mainly made by the decrease in the forest land. It could be more effective to take into account the changes in the site area and in the forest land in the process of developing the TMDL plans.

Adaptability of the high first pod height, shattering-resistant soybean cultivar 'Saegeum' to mechanized harvesting (고착협 내탈립 기계수확 적응 장류·두부용 콩 품종 '새금')

  • Kim, Hyun Tae;Han, Won Young;Lee, Byung Won;Ko, Jong Min;Lee, Yeong Hoon;Baek, In Youl;Yun, Hong Tai;Ha, Tae Joung;Choi, Man Soo;Kang, Beom Kyu;Kim, Hyun Yeong;Seo, Jeong Hyun;Kim, Hong Sik;Shin, Sang Ouk;Oh, Jae Hyun;Kwak, Do Yeon;Seo, Min Jeong;Song, Yoon Ho;Jang, Eun Kyu;Yun, Geon Sik;Kang, Yeong Sik;Lee, Ji Yun;Shin, Jeong Ho;Choi, Kyu Hwan;Kim, Dong Kwan;Yang, Woo Sam
    • Korean Journal of Breeding Science
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    • v.51 no.4
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    • pp.496-503
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    • 2019
  • The soybean cultivar, 'Saegeum', has been developed for preparing soy-paste and tofu. The soybean cultivars 'Daepung' and 'SS98207-3SSD-168' were crossed in 2003 to obtain 'Saegeum'. Single seed descent method was used to advance the generation from F3 to F5, and the plant lines with promising traits were selected from F6 to F7 by pedigree method. The preliminary yield (PYT) and advanced yield trials (AYT) were conducted from 2009 to 2010, and the regional yield trial (RYT) was conducted in 12 regions between 2011 and 2013. The morphological characteristics of 'Saegeum' were as follows: determinate plant type, white flower, tawny pubescence color, and brown pod color. Flowering and maturity dates were August 2, XXXX and October 17, XXXX, respectively. Plant height, first pod height, number of nodes, number of branches, and number of pods were 79 cm, 18 cm, 16, 2.3, and 44, respectively. The seed characteristics of 'Saegeum' were as follows: yellow spherical shape, yellow hilum, and the 100-seed weight was 25.4 g. 'Saegeum' was resistant to bacterial pustule and SMV in the field test, and its lodging resistance was mildly strong, whereas its shattering resistance was excellent. The ability of this cultivar to be processed into tofu, soybean malt, and other fermented products was comparable with that of 'Daewonkong'. The yield of 'Saegeum' in the adaptable regions was 3.02 ton ha-1. Thus, 'Saegeum' is adaptable to mechanized harvesting because of its high first pod height, as well as lodging and shattering resistance. (Registration number: 5929)

Evaluation of the Effects of the Inland Pollution Sources after Rainfall Events on the Bacteriological Water Quality in Narodo Area, Korea (강우 발생에 따른 육상오염원이 나로도 해역의 세균학적 수질에 미치는 영향 평가)

  • Park, Kunbawui;Jo, Mi Ra;Kim, Yeon Kye;Lee, Hee Jung;Kwon, Ji Young;Son, Kwang Tae;Lee, Tae Seek
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.5
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    • pp.414-422
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    • 2012
  • This study evaluated the effect of the inland pollution sources on the bacteriological water quality in Narodo area after rainfall events. Following 16 mm of rainfall, the water discharged from Dohwa Stream and contaminants from Balpo village had a very limited effect on bacteriological water quality in adjacent area and the affected area did not extend to the designated area. In comparion, after 33 mm of rainfall, the density of fecal coliforms at stations located in the mouth of Dohwa stream and the discharg point of contamination sources located in Balpo village were lower than after 16 mm of rainfall. These results were obtained during an extreme high tide near the coast the contaminants discharged from Dohwa stream and Balpo village. Therefore, it is necessary to conduct a detailed survey to examine the dffects of tides on the diffusion characteristics of the contaminants discharged from Dohwa stream and Balpo village in order to manage of Narodo area efficiently.

Evaluation of the Bacteriological Safety for the Shellfish Growing Area in Jaranman.Satyangdo Area, Korea (자란만.사량도 패류생산해역의 위생학적 안전성 평가)

  • Shim, Kil-Bo;Ha, Kwang-Soo;Yoo, Hyun-Duk;Kim, Ji-Hoe;Lee, Tae-Seek
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.42 no.5
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    • pp.442-448
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    • 2009
  • Bacteriological examination of a 12,700 ha area within Jaranman Saryangdo area, located in Jaran bay and Saryangdo island, was conducted with 35 fixed (designated areas and adjacent areas) seawater sampling stations between January 2006 and December 2008. According to results, the geometric mean range and the estimated 90th percentile range of fecal coliform counts in sea water samples collected in the designated area were <1.8-2.4 and <1.8-8.6 MPN/100mL, respectively. The estimated 90th percentile range of fecal coliform counts in sea water samples collected from 6 sampling stations in the adjacent areas were 6.1-34.6 MPN/100mL. Based on these results, bacteriological water quality of the designated areas in the Jaranman. Saryangdo area meet the NSSP (National Shellfish Sanitation Program) guidelines for approved area. The bacteriological sea water quality in Jaranman.Saryangdo area has been shown to be favorable at all investigated sampling stations except for July and August which coincided with heavy rainfall. In fact, the bacteriological water quality was not affected if rainfall was less than 30 mm rainfall. However, the degree of bacteriological contamination increased rapidly and the water quality exceeded approved NSSP guidelines set for rainfall above 60 mm.

Application of Spatial Autocorrelation for Analysis of Spatial Distribution Characteristics of Birds Observed in Namdaecheon River, Muju-gun, Jeollabuk-do, Korea (무주 남대천에 서식하는 조류의 공간적 분포특성 분석을 위한 공간자기상관 적용 연구)

  • Kang, Jong-Hyun;Kim, Yong-Ki;Yeon, Myung-Hun
    • Journal of Environmental Impact Assessment
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    • v.22 no.5
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    • pp.467-479
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    • 2013
  • This study was conducted to find out characterization of spatial distribution of birds observed in river areas. Our bird survey was carried out 4 times at 31 sites from January to September in 2011. A total of 1,609 accumulated individuals belonging to 59 species, 28 families and 11 orders were observed. In the result of spatial autocorrelation analysis using the richness index of the maximum counts of each sites, we confirmed that the distribution of birds in Namdaecheon river was clustered and the tendency of spatial autocorrelation was apparent. The area of each sites within a 200m radius was classified in four biotope categories such as agricultural land, forest, residential area and water area, and the spatial autocorrelation was analysed about four types. In the result of spatial autocorrelation analysis for four biotope categories, all types were showed the positive spatial autocorrelation, but the type of water area was higher than other types. The positive correlation was found between the water area and water birds in statistical significance. However, the forest birds had non-significance values. Therefore, it is appropriate to focus on water birds except for forest birds, when researches of bird distribution in river ecosystem is conducted. The number of bird species and individuals increased as the riverside of water area was to widen. Thus, if the areas of riverside offering the feeding and roosting area increase, it will be accommodated many birds. Also, the areas of riverside should be maintained naturally because it is an important habitats of birds. Our study area is on the outskirts the city of higher rates of forest and agricultural land, it may be unreasonable to apply our results to the whole rivers. If the research about the river flowing around the city will be conducted, it is expected to be useful to the relation study area such as ecological river's restoration.

A Design Study of the 'Pathways' According to the Characteristics of the Deteriorated Residential Area (노후주거지의 특성에 따른 '길'의 디자인 연구)

  • Park, Su-Kyoung;Moon, Jeong-Min
    • Journal of the Korean housing association
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    • v.26 no.2
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    • pp.39-46
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    • 2015
  • The 'pathways' in the Deteriorated Residential Area is the valuable place which represents the history of the community. The 'pathways' is the physical boundary which connects individual environment of private residential area to public environment and which has value as a medium for the definite site for regeneration of Deteriorated Residential Area. Thus, the 'pathways' is considered as the perfect material for the public design for spatial culture to regenerate the Deteriorated Residential Area. However, the most of the public design projects utilize the 'pathways' fragmentarily, there are few systematic studies based on the attribute of the Deteriorated Residential Area. The purpose of this study is the consideration on the attributes of the 'pathways', the detection of the spatial characteristics to find application of the 'pathways', and the cultivation of the baseline data for further research for the spatial nature of the Deteriorated Residential Area. For this study, theoretical consideration is practiced in advance to analyze the meaning of the 'pathways' and Deteriorated Residential Area, the case research is performed using design elements as the analytic frame, and the approach is inferred for systematic public design based on the above result. The objects of case research were chosen among the latest projects implemented in the Deteriorated Residential Area whose subject was 'pathways' and which showed successful result. The characteristics of them were investigated and the details were examined through the homepages of the projects, the reports related to the projects, research material, and interview with the people involved. And to conclude, 'pathways' represents the composition of contents, the space of movement, the formation of community, the landscape design, and the participatory design in the Deteriorated Residential Area. The 'pathways' also finds the proper secondary cultural material for the spatial characteristics and can create the space for the various movements, stay, and communication using the characteristics of movements. The narrow and closed space should be utilized actively to be altered into beautiful space and the Deteriorated Residential Area should be regenerated into coexistent design where people share their lives through sharing spaces.

Impact of Pollution Sources on the Bacteriological Water Quality in the Yongnam-Gwangdo Shellfish Growing Area of Western Jinhae Bay, Korea (진해만 서부 용남·광도해역의 세균학적 수질에 미치는 육상 오염원의 영향)

  • Shim, Kil Bo;Ha, Kwang Soo;Yoo, Hyun Duk;Lee, Tae Seek;Kim, Ji Hoe
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.45 no.6
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    • pp.561-569
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    • 2012
  • To evaluate the bacteriological water quality in Yongnam-Gwangdo, located in western Jinhae Bay, seawater samples were analyzed using sanitary indicator bacteria at 57 sampling stations. According to survey results from January 2007 to December 2009, the range of the geometric mean and the estimated 90th percentile for coliforms and fecal coliforms in the samples were <1.8-16.5 and 1.8-246.8 MPN/100 mL and <1.8-7.1 and 1.8-74.8 MPN/100 mL, respectively. The samples, including those taken from stations located in Wonmunman, Gwangdo, and Dangdong, showed high levels of microbial contamination caused by the climate and weather patterns in the marine environment. The bacteriological water quality in the area met Korean criteria for a designated shellfish growing area for export and National Shellfish Sanitation Program criteria for an approved shellfish growing area, except at station #49. A total of 24 direct pollution sources were discharged into the shellfish growing area. The radius of impact was calculated for each pollution source to assess the effect on the shellfish growing area. The calculated radius of impact for most of the pollution sources was below 300 m. However, the radius of impact for the combined pollution sources in Kyeonnaeryang was 93-1973 m. There were significant differences between the calculated closed sea area and actual monitoring results. The closed sea area values calculated from the fecal coliform load in drainage water tended to be higher than the actual monitoring results. Tidal currents and environmental factors such as salinity, water temperature, sunlight, and microbiological factors affect the survival of fecal indicator bacteria in seawater.

Spatio-temporal Variation of Groundwater Level and Electrical Conductivity in Coastal Areas of Jeju Island

  • Lim, Woo-Ri;Park, Won-Bae;Lee, Chang-Han;Hamm, Se-Yeong
    • Journal of the Korean earth science society
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    • v.43 no.4
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    • pp.539-556
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    • 2022
  • In the coastal areas of Jeju Island, composed of volcanic rocks, saltwater intrusion occurs due to excessive pumping and geological characteristics. Groundwater level and electrical conductivity (EC) in multi-depth monitoring wells in coastal areas were characterized from 2005 to 2019. During the period of the lowest monthly precipitation, from November 2017 until February 2018, groundwater level decreased by 0.32-0.91 m. During the period of the highest monthly precipitation, from September 2019 until October 2019, groundwater level increased by 0.46-2.95 m. Groundwater level fluctuation between the dry and wet seasons ranged from 0.79 to 3.73 m (average 1.82 m) in the eastern area, from 0.47 to 6.57 m (average 2.55 m) in the western area, from 0.77 to 8.59 m (average 3.53 m) in the southern area, and from 1.06 to 12.36 m (average 5.92 m) in the northern area. In 2013, when the area experienced decreased annual precipitation, at some monitoring wells in the western area, the groundwater level decreased due to excessive groundwater pumping and saltwater intrusion. Based on EC values of 10,000 ㎲/cm or more, saltwater intrusion from the coastline was 10.2 km in the eastern area, 4.1 km in the western area, 5.8 km in the southern area, and 5.7 km in the northern area. Autocorrelation analysis of groundwater level revealed that the arithmetic mean of delay time was 0.43 months in the eastern area, 0.87 months in the northern area, 10.93 months in the southern area, and 17.02 months in the western area. Although a few monitoring wells were strongly influenced by nearby pumping wells, the cross-correlation function of the groundwater level was the highest with precipitation in most wells. The seasonal autoregressive integrated moving average model indicated that the groundwater level will decrease in most wells in the western area and decrease or increase in different wells in the eastern area.