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A Study on Optimal Site Selection for Automatic Mountain Meteorology Observation System (AMOS): the Case of Honam and Jeju Areas (최적의 산악기상관측망 적정위치 선정 연구 - 호남·제주 권역을 대상으로)

  • Yoon, Sukhee;Won, Myoungsoo;Jang, Keunchang
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.18 no.4
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    • pp.208-220
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    • 2016
  • Automatic Mountain Meteorology Observation System (AMOS) is an important ingredient for several climatological and forest disaster prediction studies. In this study, we select the optimal sites for AMOS in the mountain areas of Honam and Jeju in order to prevent forest disasters such as forest fires and landslides. So, this study used spatial dataset such as national forest map, forest roads, hiking trails and 30m DEM(Digital Elevation Model) as well as forest risk map(forest fire and landslide), national AWS information to extract optimal site selection of AMOS. Technical methods for optimal site selection of the AMOS was the firstly used multifractal model, IDW interpolation, spatial redundancy for 2.5km AWS buffering analysis, and 200m buffering analysis by using ArcGIS. Secondly, optimal sites selected by spatial analysis were estimated site accessibility, observatory environment of solar power and wireless communication through field survey. The threshold score for the final selection of the sites have to be higher than 70 points in the field assessment. In the result, a total of 159 polygons in national forest map were extracted by the spatial analysis and a total of 64 secondary candidate sites were selected for the ridge and the top of the area using Google Earth. Finally, a total of 26 optimal sites were selected by quantitative assessment based on field survey. Our selection criteria will serve for the establishment of the AMOS network for the best observations of weather conditions in the national forests. The effective observation network may enhance the mountain weather observations, which leads to accurate prediction of forest disasters.

DC Electric Field Characteristics considering Thermal Effect for HVDC Slip-on Type Outdoor Termination (HVDC 슬립 온형 기중 종단접속함에 대한 열 영향 반영 DC 전계 특성 평가)

  • Kwon, Ik-Soo;Hwang, Jae-Sang;Koo, Jae-Hong;Sakamoto, Kuniaki;Lee, Bang-Wook
    • KEPCO Journal on Electric Power and Energy
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    • v.1 no.1
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    • pp.39-46
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    • 2015
  • A outdoor termination installed at the outdoor substation is required to connect undergroud cables and overhead transmission lines. The joint box for AC transmission system is already developed and widely used to interconnect overhead and undergroud systems. But the development of the joint box for DC transmission system was only introduced from China and Japan, but theire developemnt staus and core technologies were not fully reported. In order to implement HVDC systems connecting ovehead transmission lines and undergroud cables, a outdoor termination should be developed, but the detailed specifications and information of this device were not reported. It is estimated that the development of the joint box for DC environment has some technical obstacles including insulating materials, electric field mitigation, thermal temperature rise, and space charge accumuations. Among this, the most important one is the DC elctrical insualtion design. Therefore, in order to investigate the DC elctrical insualton design of outdoor termination, the design of AC slip-on type outdoor termination is reffered, and DC electric field analysis performed to verify the possiblity of application of AC joint box into DC joint box. Especially for DC electric field analysis, temperature rise of insualting materials of a joint box was considered, because the conductivity of materials could be changed due to temperature rise. Furthermore, DC electric field analysis considering transinet state, and polarity reversal state were also investigated to verify which state is the most severe condition for the DC joint box. From the simualtion resulsts, it was shown that the value and the position of maximum electric field was obtained comparing AC state, DC state without temperaure rise, and DC state with temperaure rise. And it was confimred that severe DC electric field was observed considing temperaure rise. Finally, in order to reduce DC eletric field intensifation, different configuration of the joint box was applied and it was not possible to obtain satisfactory results. It means that the slight change of configuration of AC joint box was not the suitable soluton for DC joint box. It is essential to establish novel DC insulaton design skills and method for DC joint box to commercialze this product in the near future.

An Efficient Algorithm for Streaming Time-Series Matching that Supports Normalization Transform (정규화 변환을 지원하는 스트리밍 시계열 매칭 알고리즘)

  • Loh, Woong-Kee;Moon, Yang-Sae;Kim, Young-Kuk
    • Journal of KIISE:Databases
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    • v.33 no.6
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    • pp.600-619
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    • 2006
  • According to recent technical advances on sensors and mobile devices, processing of data streams generated by the devices is becoming an important research issue. The data stream of real values obtained at continuous time points is called streaming time-series. Due to the unique features of streaming time-series that are different from those of traditional time-series, similarity matching problem on the streaming time-series should be solved in a new way. In this paper, we propose an efficient algorithm for streaming time- series matching problem that supports normalization transform. While the existing algorithms compare streaming time-series without any transform, the algorithm proposed in the paper compares them after they are normalization-transformed. The normalization transform is useful for finding time-series that have similar fluctuation trends even though they consist of distant element values. The major contributions of this paper are as follows. (1) By using a theorem presented in the context of subsequence matching that supports normalization transform[4], we propose a simple algorithm for solving the problem. (2) For improving search performance, we extend the simple algorithm to use $k\;({\geq}\;1)$ indexes. (3) For a given k, for achieving optimal search performance of the extended algorithm, we present an approximation method for choosing k window sizes to construct k indexes. (4) Based on the notion of continuity[8] on streaming time-series, we further extend our algorithm so that it can simultaneously obtain the search results for $m\;({\geq}\;1)$ time points from present $t_0$ to a time point $(t_0+m-1)$ in the near future by retrieving the index only once. (5) Through a series of experiments, we compare search performances of the algorithms proposed in this paper, and show their performance trends according to k and m values. To the best of our knowledge, since there has been no algorithm that solves the same problem presented in this paper, we compare search performances of our algorithms with the sequential scan algorithm. The experiment result showed that our algorithms outperformed the sequential scan algorithm by up to 13.2 times. The performances of our algorithms should be more improved, as k is increased.

A Comparison Study of Alkalinity and Total Carbon Measurements in $CO_2$-rich Water (탄산수의 알칼리도 및 총 탄소 측정방법 비교 연구)

  • Jo, Min-Ki;Chae, Gi-Tak;Koh, Dong-Chan;Yu, Yong-Jae;Choi, Byoung-Young
    • Journal of Soil and Groundwater Environment
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    • v.14 no.3
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    • pp.1-13
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    • 2009
  • Alkalinity and total carbon contents were measured by acid neutralizing titration (ANT), back titration (BT), gravitational weighing (GW), non-dispersive infrared-total carbon (NDIR-TC) methods for assessing precision and accuracy of alkalinity and total carbon concentration in $CO_2$-rich water. Artificial $CO_2$-rich water(ACW: pH 6.3, alkalinity 68.8 meq/L, $HCO_3^-$ 2,235 mg/L) was used for comparing the measurements. When alkalinity measured in 0 hr, percent errors of all measurement were 0~12% and coefficient of variation were less than 4%. As the result of post-hoc analysis after repeated measure analysis of variance (RM-AMOVA), the differences between the pair of methods were not significant (within confidence level of 95%), which indicates that the alkalinity measured by any method could be accurate and precise when it measured just in time of sampling. In addition, alkalinity measured by ANT and NDIR-TC were not change after 24 and 48 hours open to atmosphere, which can be explained by conservative nature of alkalinity although $CO_2$ degas from ACW. On the other hand, alkalinity measured by BT and GW increased after 24 and 48 hours open to atmosphere, which was caused by relatively high concentration of measured total carbon and increasing pH. The comparison between geochemical modeling of $CO_2$ degassing and observed data showed that pH of observed ACW was higher than calculated pH. This can be happen when degassed $CO_2$ does not come out from the solution and/or exist in solution as $CO_{2(g)}$ bubble. In that case, $CO_{2(g)}$ bubble doesn't affect the pH and alkalinity. Thus alkalinity measured by ANT and NDIR-TC could not detect the $CO_2$ bubble although measured alkalinity was similar to the calculated alkalinity. Moreover, total carbon measured by ANT and NDIR-TC could be underestimated. Consequently, it is necessary to compare the alkalinity and total carbon data from various kind of methods and interpret very carefully. This study provide technical information of measurement of dissolve $CO_2$ from $CO_2$-rich water which could be natural analogue of geologic sequestration of $CO_2$.

Derivation of Green Infrastructure Planning Factors for Reducing Particulate Matter - Using Text Mining - (미세먼지 저감을 위한 그린인프라 계획요소 도출 - 텍스트 마이닝을 활용하여 -)

  • Seok, Youngsun;Song, Kihwan;Han, Hyojoo;Lee, Junga
    • Journal of the Korean Institute of Landscape Architecture
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    • v.49 no.5
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    • pp.79-96
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    • 2021
  • Green infrastructure planning represents landscape planning measures to reduce particulate matter. This study aimed to derive factors that may be used in planning green infrastructure for particulate matter reduction using text mining techniques. A range of analyses were carried out by focusing on keywords such as 'particulate matter reduction plan' and 'green infrastructure planning elements'. The analyses included Term Frequency-Inverse Document Frequency (TF-IDF) analysis, centrality analysis, related word analysis, and topic modeling analysis. These analyses were carried out via text mining by collecting information on previous related research, policy reports, and laws. Initially, TF-IDF analysis results were used to classify major keywords relating to particulate matter and green infrastructure into three groups: (1) environmental issues (e.g., particulate matter, environment, carbon, and atmosphere), target spaces (e.g., urban, park, and local green space), and application methods (e.g., analysis, planning, evaluation, development, ecological aspect, policy management, technology, and resilience). Second, the centrality analysis results were found to be similar to those of TF-IDF; it was confirmed that the central connectors to the major keywords were 'Green New Deal' and 'Vacant land'. The results from the analysis of related words verified that planning green infrastructure for particulate matter reduction required planning forests and ventilation corridors. Additionally, moisture must be considered for microclimate control. It was also confirmed that utilizing vacant space, establishing mixed forests, introducing particulate matter reduction technology, and understanding the system may be important for the effective planning of green infrastructure. Topic analysis was used to classify the planning elements of green infrastructure based on ecological, technological, and social functions. The planning elements of ecological function were classified into morphological (e.g., urban forest, green space, wall greening) and functional aspects (e.g., climate control, carbon storage and absorption, provision of habitats, and biodiversity for wildlife). The planning elements of technical function were classified into various themes, including the disaster prevention functions of green infrastructure, buffer effects, stormwater management, water purification, and energy reduction. The planning elements of the social function were classified into themes such as community function, improving the health of users, and scenery improvement. These results suggest that green infrastructure planning for particulate matter reduction requires approaches related to key concepts, such as resilience and sustainability. In particular, there is a need to apply green infrastructure planning elements in order to reduce exposure to particulate matter.

A Study on Priority Analysis of Improvements for Success Factors in Steps of Formation Process of Cooperation Network (산학협력 네트워크 형성 과정의 단계별 성공 요인에 대한 실행 개선 요구 분석 연구)

  • Ahn, Jae-Yeong;Lee, Byung-Wook
    • Journal of vocational education research
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    • v.36 no.1
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    • pp.77-103
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    • 2017
  • The purposes of this study are 1) to analyse the importance and performance of the success factors in steps of Formation process Of Cooperation NetWork(FoCNW) of educational institutions and businesses, and 2) to draw the success factors that need improvement. To achieve these purposes a survey research was conducted with a group of 1,098 (professors, teachers and workers in charge of cooperation at universities, technical colleges, vocational high schools and businesses which are equipped with a cooperation system), and 339 questionnaires were analyzed. The major results of the study are as follows. Firstly, while cooperation workers showed high recognition on the importance of success factors in steps of FoCNW, their performance of those factors was relatively low. Secondly, both the recognition of importance and performance of success factors in steps of FoCNW was higher in educational institutions than in businesses. Thirdly, the success factors in need of improvements from both educational institutions and businesses are 'collecting outer information and consulting' and 'publicizing cooperation competency', 'setting cooperative activities (programs) and contents of agreements', 'managing cooperation quality formally', 'drawing plans for sustainable cooperation improvement' and 'diffusing cooperation network'. The success factors in need of improvements from educational institutions are 'perceiving necessity of and forming consensus on cooperation' and 'deciding and supporting the worker in charge of cooperation', and 'participating and sharing of organization members'. The success factors in need of improvements from businesses are 'deciding goals and performance strategies', 'developing mutual understanding and checking possibility of cooperation with potential partners', and 'evaluating cooperation activities and their outcomes and providing feedback' and 'adjusting contents of agreements and deciding whether to maintain cooperation'. Therefore, efforts from each partner to improve those factors and support from related organizations are necessary.

Research on the Re-organization of the Administration of Labor's Records in the custody of the National Archives (노동청 기록의 재조직에 관한 연구 - 국가기록원 소장 기록을 중심으로 -)

  • Kwak, Kun-Hong
    • The Korean Journal of Archival Studies
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    • no.23
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    • pp.141-178
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    • 2010
  • The Administration of Labor was responsible for the technical and practical functions like policy-making of labor matters and implementing the relevant laws. However, there has been a few record transferred to the National Archives to help find out the labor policy-making process. This is one of the typical examples that shows the discontinuity and unbalance, and disorderly filing of the administrative records in Korea. Naturally it is almost impossible to retrieve the appropriate content through the records file-name. Users should be at the trouble to compare the record items and their content one by one. For the re-organization of the Administration of Labor' records, this research suggests the four-level analysis of functions of the Administration. The Administration of Labor' survived records could be linked to each level function. And the publication of the 'Records Abstract Catalog' providing users with more information about the records would pave the way for easier access to the records. In addition, it also suggests the logical re-filing of the survived records of which we cannot find the order or sequence. This re-organization of the survived records would help to establish the acquisition and appraisal policy of the labor records as well as the new way of description and finding tool hereafter. Drawing up labor history map is a starting point for the acquisition strategy of the labor records, which could allow users to gain systematic access on the survived records. Of course, extensive investigation and research on the survived records is a prerequisite for the map. It would be required to research on the survived records of the other government agencies, including economic-social area ministries and investigation agencies and the National Assembly as well. It is also needed to arrange and typify the significant incidents and activities on thematic and periodic frames in the labor history. If possible to understand or connect the survived records and these accomplishments comprehensively, it would be of great help for the acquisition of the labor records and the related oral records projects.

Influence of Corporate Venture Capital on Established Firms' Aquisition of Startups (스타트업 인수 시 기업벤처캐피탈(CVC)이 모기업에 미치는 영향)

  • Kim, MyungGun;Kim, YoungJun
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.14 no.2
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    • pp.1-13
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    • 2019
  • As a way to find new and innovative technologies, many companies have invested in and acquired skilled startups. Because startups are usually small in size and have a small history of past business experience, there are many risks involved in acquiring them as they have limited technical skills and business feasibility verification methods. Thus, venture capital plays an important role in discovering and investing competitive startups. While Independent Venture Capital generally values financial returns, Corporate Venture Capital, which plays investment roles in the firm, values business synergies with the parent company from a strategic perspective. In an industry sector where development of technology is rapid and whether new technology is held determines a company's competitiveness, existing companies incorporate startups with innovative technologies into their investment portfolios, collaborate together, and take over for comprehensive cooperation. In addition, new investments and acquisitions are carried out through the management of portfolio companies to obtain and utilize industry information. In this paper, major U.S. companies listed in the U.S. verified their investment activities through corporate venture capital and their impact on parent companies and startups through regression, while the parent company's acquisition performance was analyzed through an event study based on a stock price analysis. The criteria for startup were defined as companies with less than 12 years of experience, and the analysis showed that the parent companies with corporate venture capital with a larger number of investments actively take over startups. In addition, increasing corporate venture capital's financial investment activities shows a negative impact on the parent companies' acquisition activities, and the acquisition performance increased when the parent companies took over startups in its portfolio.

Structuralization of Elective Courses in High School Home Economics(Subject Group) in Preparation for the Next Curriculum (차기 교육과정을 대비한 고등학교 가정교과(군) 선택과목의 구조화)

  • Yu, Nan Sook;Baek, Min Kyung;Ju, Sueun;Han, Ju;Park, Mi Jeong
    • Journal of Korean Home Economics Education Association
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    • v.33 no.1
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    • pp.129-149
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    • 2021
  • The purposes of this study were to examine the current status of the establishment of home economics-related departments in colleges and universities and the changes required in the home economics curriculum of secondary schools, and to structure the elective courses of home economics subject(group) that can be organized in the next high school curriculum. To achieve these purposes, related literature and data were analyzed, and a questionnaire survey and FGI were conducted by home economics experts. The research results are as follows. First, home economics was considered to be highly related not only to the human ecology but also to social sciences, education, engineering, and arts and physical education. The numbers of technical colleges and 4-year universities with departments related to home economics were 1,405 and 961 respectively in 2019. Therefore, it was confirmed that there is a sufficient basis for opening home economics subject(group) elective courses in high school. Second, in the secondary school home economics curriculum, the concepts of culture, relations, independence, and sustainability were emphasized based on the changing life patterns and values. It was proposed that the contents of the home economics course would be structured in a way that allows deep and high-level thinking and helps students to enjoy culture. This demand can be implemented by diversifying, specializing, and structuring the elective courses of the home economics subject(group). Third, a total of 18 elective subjects and subject outlines were structured in the fields of child/family, food/nutrition, clothing, housing, consumption/family management, and home economics integration. This study results will contribute to the establishment of the high school credit system by providing basic information for organizing the next home economics curriculum, and expanding the options for home economics subject(group) to high school students.

A case study of blockchain-based public performance video platform establishment: Focusing on Gyeonggi Art On, a new media art broadcasting station in Gyeonggi-do (블록체인 기반 공연영상 공공 플랫폼 구축 사례 연구: 경기도 뉴미디어 예술방송국 경기아트온을 중심으로)

  • Lee, Seung Hyun
    • Journal of Service Research and Studies
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    • v.13 no.1
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    • pp.108-126
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    • 2023
  • This study explored the sustainability of a blockchain-based cultural art performance video platform through the construction of Gyeonggi Art On, a new media art broadcasting station in Gyeonggi-do. In addition, the technical limitations of video content transaction using block chain, legal and institutional issues, and the protection of personal information and intellectual property rights were reviewed. As for the research method, participatory observation methods such as in-depth interviews with developers and operators and participation in meetings were conducted. The researcher participated in and observed the entire development process, including designing and developing blockchain nodes, smart contracts, APIs, UI/UX, and testing interworking between blockchain and content distribution services. Research Question 1: The results of the study on 'Which technology model is suitable for a blockchain-based performance video content distribution public platform?' are as follows. 1) The blockchain type suitable for the public platform for distribution of art performance video contents based on the blockchain is the private type that can be intervened only when the blockchain manager directly invites it. 2) In public platforms such as Gyeonggi ArtOn, among the copyright management model, which is an art based on NFT issuance, and the BC token and cloud-based content distribution model, the model that provides content to external demand organizations through API and uses K-token for fee settlement is suitable. 3) For public platform initial services such as Gyeonggi ArtOn, a closed blockchain that provides services only to users who have been granted the right to use content is suitable. Research question 2: What legal and institutional problems should be reviewed when operating a blockchain-based performance video distribution public platform? The results of the study are as follows. 1) Blockchain-based smart contracts have a party eligibility problem due to the nature of blockchain technology in which the identities of transaction parties may not be revealed. 2) When a security incident occurs in the block chain, it is difficult to recover the loss because it is unclear how to compensate or remedy the user's loss. 3) The concept of default cannot be applied to smart contracts, and even if the obligations under the smart contract have already been fulfilled, the possibility of incomplete performance must be reviewed.