• 한국농공학회논문집
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• 제53권4호
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• pp.1-9
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• 2011

Forest area covers 64 % of the national land of Korea and the forest plays a pivotal role in the hydrological process such as flood, drought, runoff, infiltration, evapotranspiration, etc. In this study, soil moisture monitoring for conifer forest in experimental forest of Seoul National University has been conducted using FDR (Frequency Domain Reflection) for 6 different soil layers, 10, 20, 30, 60, 90 and 120 cm during 2009~2010, and precipitation data was collected from nearby AWS (Automatic Weather Station). Soil moisture monitoring data were used to estimate soil moisture recession constant (SMRC) for analyzing soil moisture recession characteristics. From the results, empirical soil moisture recession equations were estimated and validated to determine the feasibility of the result, and soil moisture contents of measured and calculated showed a similar tendency from April to November. Thus, the results can be applied for soil moisture estimation and provided the basic knowledge in forest soil moisture consumption. Nevertheless, this approach demonstrated applicability limitations during winter and early spring season due to freezing and melting of snow and ice causing peculiar change of soil moisture contents.

• 농촌지도와개발
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• 제10권2호
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• pp.229-237
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• 2003

Since the 1960s in Korea, major broadcasting channels broadcasted farm television programs, however, airing of these programs were reduced in the 1990s. This was due to the declining number of farmers, and the low popularity rating of farm television programs. To cope with the situation, agriculture businessmen, farmers, and the officials concerned tried to acquire the independent farming television channel in cable television and satellite television, In 1998, one cable television channel started broadcasting, while another channel in satellite television began its broadcasting in 2001. One of the major concerns of the people in the broadcasting was actualization of the public interests in the new media multi-channel age. Recognizing this point, the study explored a few areas of concern such as conceptualizations of the public interest of the people in the digital age, examination of the surroundings of program production and marketing, and survey the media use behavior of target audience - rural residents; In the concept of the public interest, there are two points of view; market focused and democratic principle oriented. As the digitalization of broadcast advances and the logic of economics prevails, it is difficult to offer the public broadcasting service to farmers, however, democratic principles should be more emphasized. The rural resident prefer major terrestrial television channel to cable television and satellite television channel, and in media use behavior, the medium of major terrestrial television would be more useful for farm broadcasting.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.49-52
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• 2003

As the power demand has increased, it is expected that the transmission system will have more complicated problems under the influence of investment reduction for overall power system. The route length per MW demand will be reduced gradually from 0.6［C-km/㎿］ to 0.53 ［C-km/㎿］ in 2010. This comes up to a real serious problem of system planning and operation viewpoints HTS power technologies have properties to solve these complex transmission and distribution constraints, especially for metropolitan area, in the future. As the HTS technology has developed, the HTS cable technology can be the most effective alternative to solve the future expected transmission constraints as compared with other countermeasures in terms of economics, environments and system operation. This paper describes the general application methodology of developing 22.9 ㎸ HTS cable by CAST for practical distribution system, particularly, step-by-step application methodology of 22.9 ㎸ HTS cable to substitute the existing and planning 154 ㎸ cable. In this scheme, almost of the downtown 154 ㎸ substation of metropolitan city such as Seoul will be changed into 22,9 ㎸ switching station.

• 한국BIM학회 논문집
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• 제8권3호
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• pp.1-11
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• 2018

Gentrification is appearing in various areas. Especially commercial gentrification, the value of property is rising and it means the change of commercial sphere in revitalizing the underdeveloped commercial. In this study, Identify the process of increasing the franchise rate, which is changing gradually in commercial areas. We analyze prior studies on gentrification and franchise. Identify changing of land use distribution in Samcheong-dong area and analyze franchise change process. As a result of analyzing the changing of land use in Samcheong-dong area, the number of houses and other uses has continued to decrease. In the case of franchises, it increased sharply and in the case of general commercial, it steadily decreased. Looking at analyzing the franchise change process in Samcheong-dong area, In the franchise change process, there is very little change in land use from residential and other uses to general commercial. Representative spaces that show the process of franchise change are around the three-way streets, around the community service center and around the police station.

• Journal of Plant Biology
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• 제7권2호
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• pp.1-8
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• 1964

Cha, Jong Whan (Dept. of Biology, Graduate School, Dong Kuk Univ.) The changes of chemical properties of forest soils in dry and wet seasons. Kor. Jour. Bot. VII(2): 1-8, 1964. Soil selected for the present investigation was collected from a mountain of the Forestry Experiment Station of the vicinity of Seoul. The forest communities studied were three forest and a unplanted soils. The soil samples were obtained from each forest type during dry and wet seasons. And these samples were collected from four horizons of all communities respectively. It was showed that exchangeable hydrogen was increased by rainfall, and total exchangeable base decreased in the same way. The content of nitrogen is washed away by rainfall, especially ammonium nitrogen was highly significant between dry and wet season. On the contrary, organic matter and available phosphorus were of no significant difference between dry and wet seasons. The values of pH appeared a different response in dry and wet seasons according to the plant communities. The needle-leaved forest soils showed more acidity than the broad-leaved forest soils, and the least acidity in open places. All nutrients in soil studied gradually decreased down the profiles. According to statistical analyses of the soil components among all soil horizons, total exchangeable bases in wet season indicated only significant at 1%. Exchangeable hydrogen and organic matter of the soil in dry season was particularly very low with increased depth in the profile. The fertility level of most forested soils selected for the present investigation is low according to chemical tests for available nutrient elements.

• 대한안전경영과학회지
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• 제16권2호
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• pp.19-29
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• 2014

Korean societal concern for the train accidents is fast and widely increasing with an ever-increasing demand and use for KTX. Most of these train accidents are inclined to be caused by human error. Experts used to attribute the causes of human error to the defects in various aspects such as technology, organizational system, practices, corporate culture, and/or human resource itself. Among the diverse causes of human error, an important one, even though it was rarely focused, may be the issue of impact of rule or procedure change on human error. Giving attention to the implicit importance of this issue, this study intends to highlight the theme of frequent procedure change in railway driving manual as a critical factor of human error. To attain this purpose mentioned above, dual methodologies were adopted. One is to qualitatively analyze the real cases of procedure change in relevant manuals followed by the incident case(passing the station scheduled to stop) happened lately. Another is to quantitatively perform statistical analysis based on questionnaires received from 224 train drivers. Results show that frequent changes in internal affairs procedure is or may be an important factor causing stress and human error from train drivers.

• 농업과학연구
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• 제47권3호
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• pp.509-517
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• 2020

Geographic information system (GIS) sewer network data are a fundamental input material for urban inundation modeling, which is important to reduce the increasing damages from urban inundation due to climate change. However, the essential attributes of the data built by a local government are often missing because the purpose of building the data is the maintenance of the sewer system. Inconsistent simplification and supplementation of the sewer network data made by individual researchers may increase the uncertainty of flood simulations and influence the inundation analysis results. Therefore, it is necessary to develop a basic algorithm to convert the GIS-based sewage network data into input data that can be used for inundation simulations in consistent way. In this study, the format of GIS-based sewer network data for a watershed near the Sadang Station in Seoul and the Oncheon River Basin in Busan was investigated, and a missing data supplementing algorithm was developed. The missing data such as diameter, location, elevation of pipes and manholes were assumed following a consistent rule, which was developed referring to government documents, previous studies, and average data. The developed algorithm will contribute to minimizing the uncertainty of sewer network data in an urban inundation analysis by excluding the subjective judgment of individual researchers.

• 한국응급구조학회지
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• 제19권2호
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• pp.99-115
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• 2015

Purpose: This study aimed to provide basic data for clinical training program development by analyzing the operating conditions and satisfaction in a clinical training program for 119 emergency medical technicians (EMTs) in South Korea. Methods: Data from 84 EMTs were collected on June 19, 2014. We administered a 64-item questionnaire about operating conditions and satisfaction in the clinical training program, and analyzed data (SPSS v 21.0). Results: The degree of performance in the field, importance of the item in the field, and level of difficulty were 3.36, 4.23, and 3.21, respectively. In the number of times that an item was directly performed according to the subjects' general characteristics a statistically difference in sex (p = .000), duty (p =.021), and total working time of trainees (p = .002). The subjects' total satisfaction score was 3.77. The difference in satisfaction according to the subjects' characteristics was a statistically significant in terms of sex (p = .016) and clinical training area (p = .005). Conclusion: A more efficient training system for hospital clinical training courses should be developed. The operation condition analyzed in this research may contribute to the improvement of the performance of EMTs.

• 대한교통학회지
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• 제16권4호
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• pp.33-52
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• 1998

본 연구에서는 국토동남권의 인구와 고용에 따른 공간구조 변화과정을 분석하고 향후 경부고속철도 건설에 따른 변화를 예측하였다. 본 연구의 공간범위는 양산시, 울산시, 경주시, 포항시를 대상지역으로 한 총 52개 지역공간을 기초분석 단위로 하였다. 국토동남권내 인구와 고용의 공간구조를 분석 전망하기 위하여 공간구조 측정방법인 로렌쯔곡선측정식, 중심성측정식, 접근도측정식등의 기법을 이용하였으며 공간적 집중과 분산의 정도를 전망하였다. 본 연구에서는 1970년부터 1994년까지 인구와 고용구조를 조사하여 공간구조의 변화과정을 분석하였다. 그리고 현재까지 계획된 건설 공정을 바탕으로 개통 예정시점인 2006년부터 2016년까지의 국토동남권 공간구조를 전망하기 위하여 3가지 시나리오에 따라 인구와 고용의 공간구조 변화를 예측하였다. 시나리오(1)은 경부고속철도의 서울-대구 구간을 우선적으로 건설하여 운행하고 대구-부산 구간은 경부철도의 기존선을 전철화하여 활용하는 방안이다. 시나리오(2)는 경부고속철도를 기본계획과 같이 2006년 완공하고 국토동남권내 1개 정차역인 경주시 건천역을 개통하였을 경우이다. 시나리오(3)은 시나리오(2)와 같은 조건하에서 국토동남권내 2개 정차역인 건천역과 울산역을 개통하였을 경우이다. 시나리오 (2)와 (3)의 경우는 일본 시즈오카현 노선을 경유하는 신간선 주변의 지역공간 특성이 우리나라 국토동남권과 유사함을 근거로 신간선개통전과 개통후의 지역공간 변화를 분석하여 본 연구와 비교하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2009년도 추계학술대회
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• pp.120-123
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• 2009

WiBro는 2006년 6월 상용화 서비스를 시작으로, 60km/h의 속도에도 3Mbps의 속도를 제공하는 모바일 인터넷 서비스로써 현재 서울 및 수도권 그리고 각 지방 주요도시에서 서비스 중이다. 본 논문에서는 V2I(Vehicle-To-Infrastructure)통신이라 불리는 차량-인프라간 통신에서 무인차량제어통신을 위해 현재 상용화된 무선통신기술에 대해 분석하고 WiBro 기술을 제안한다. V2I 통신환경 구축을 위해 각 WiBro 단말기를 2대의 노트북에 장착하여 차량을 운행하였으며, 각 기지국을 중심으로 커버리지, 전송률, 지연율, 손실률과 주차장 환경에서의 전송률을 테스트 하였다.