• Journal of KIISE
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• v.42 no.4
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• pp.504-511
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• 2015

Recently, the amount of data is rapidly increasing with the popularity of the SNS and the development of mobile technology. So, it has been actively studied for the effective data analysis schemes of the large amounts of data. One of the typical schemes is a Voronoi diagram based on kNN join algorithm (VkNN-join) using MapReduce. For two datasets R and S, VkNN-join can reduce the time of the join query processing involving big data because it selects the corresponding subset Sj for each Ri and processes the query with them. However, VkNN-join requires a high computational cost for constructing the Voronoi diagram. Moreover, the computational overhead of the VkNN-join is high because the number of the candidate cells increases as the value of the k increases. In order to solve these problems, we propose a MapReduce-based kNN-join query processing algorithm for analyzing the large amounts of data. Using the seed-based dynamic partitioning, our algorithm can reduce the overhead for constructing the index structure. Also, it can reduce the computational overhead to find the candidate partitions by selecting corresponding partitions with the average distance between two seeds. We show that our algorithm has better performance than the existing scheme in terms of the query processing time.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.15 no.1
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• pp.31-44
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• 2020

Accelerators that invest in early startups, as well as nursery and overall management, have recently emerged as "key players" in the startup ecosystem. This can be proved by the case where the number of domestic accelerators registered in the Korean Ministry of SMEs and Startups has recently reached 208. Accelerators provide the necessary education for early-stage companies, including guidance for a certain period of time, and support startups in ways such as demo days to attract subsequent investment after the seed investment. There is not much research in academia about what factors impact on these accelerators when making investment decisions at the time of seed investment. In this study, we checked the meaning and function of the accelerator and tried to analyze what factors affect on accelerators when making a decision to invest in startups. The research method is based on a literature survey of previous studies on investment decision-making factors of venture capital and angel investors, and a lens model and judgment analysis method through empirical research targeting 43 accelerator investment decision-makers. Empirical analysis shows that accelerators have three of the key factors to consider when choosing the first startup to invest and educate; entrepreneurs' entrepreneurial traits, their product and service expertise and a potential return on success. This will provide an opportunity for early startups to gain strategic access to accelerators when they need money or need a structured educational program. Also, the results obtained through this research will be a kind of guideline for startups to attract accelerators' investment. The significance of this study is that discriminatory evidence was presented on the accelerator determinants of investment, and it would be highly suggestive to startups and related public institutions.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.480-484
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• 1997

Sugars in Korean ginseng(Panax ginseng C. A. Meyer) were studied by HPLC, TLC and NMR. The sugars in Korean ginseng were crushed and extracted by boiling for 30min. Korean ginseng was found to contain 3.77% of sucrose, 3.50% of maltose, 0.09% of fructose and 0.04% of glucose and 3.90% of starch. No other mono- and oligosaccharides were detected in the test of TLC and HPLC. Starch in ginseng showed only signal of $\alpha$-1, 4-glucosidic linkage by proton NMR analysis, and showed 92% of absorbance by iodine reaction compared with amylose(DP 117). These results indicated that starch in Korean ginseng is composed by only amylose. Pectin content in ginseng showed 0.22% as galcturonic acid by carbazole analysis.

• Analytical Science and Technology
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• v.12 no.1
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• pp.1-6
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• 1999

Copper(II) complex of piperidine dithiocarbamate (Pipdtc) was synthesized from the reaction of Cu(II) and piperidine dithiocarbamate. The possible structure of the complex was proposed on the basis of elemental analysis, molar conductivity, infrared spectroscopy, electronic absorption spectroscopy, and $^{13}C-NMR$ studies. The extraction of copper(II)-Pipdtc complex by carbon tetrachloride can be achieved in the pH range of 6.0~10. The solution of copper(II) with piperidine dithiocarbamate was bey Beer's law in the concentration up to ${\sim}8.0{\times}10^{-5}M$ at pH 9.0.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.118-118
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• 2019

현재 홍수예보는 정형데이터인 유량 및 수위 등을 활용하여 이뤄지고 있다. 하지만 실제 사람들이 체감하는 홍수에 대한 위험도는 홍수예보 발령과는 달라 홍수예보가 이뤄지지 않은 지역에서 인명사고가 발생하기도 한다. 이는 수위 측정이 이뤄지지 않는 소규모 하천이나 사람들의 유동성이 큰 도심지역에서 빈번하게 발생한다. 이를 보완하기 위해서는 사람들의 체감 정도 및 인구의 유동성을 고려한 비정형데이터를 활용해야 한다. 특히 소셜 네트워크 서비스(Social Network Commuinty, SNS)를 사용하는 사람들이 많아지면서 기존에 사용되어 왔던 정형데이터 센서 이외의 데이터를 제공한다. 또한 개개인이 작성하는 글은 실시간으로 활용이 가능하여 인구의 유동성 및 시 공간적 데이터를 얻기에 유용하여 활용성이 매우 높은 비정형데이터이다. 따라서 본 연구에서는 SNS 데이터를 추출하고 이를 분석하여 2018년에 발생했던 강우사상과의 패턴을 비교하여 홍수예보에서의 활용성을 분석하였다. 홍수와 관련한 키워드를 중심으로 시 공간적 정보 및 추출이 가능한 웹 크롤러(Web Crawler) 프로그램을 작성하였으며 이를 토대로 데이터를 수집하였다. 수집한 데이터와 실제 홍수사상을 비교 분석을 한 결과 강우량 및 수위와 해당 지역에 대한 데이터의 양이 유사한 패턴을 보인 것으로 확인되었다. 실시간으로 데이터를 수집하고 이를 분석하여 리드타임을 충분히 확보한다면 홍수예측에 활용 가능할 것이라 생각된다. 본 연구는 한국건설기술연구원 19주요-대4-시드사업인 '커뮤니티 빅데이터 패턴 해석을 통한 수난(水難) 발생 및 규모 예측 기술 개발(20190126-001) '로 수행되었습니다.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.2
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• pp.91-102
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• 2014

Recent trends in urban policies show the increasing importance of urban parks. Moreover the park policy and planning are increasingly important for the good urban park system. Comparative studies in the operational system and planning contents of the parks and green space plans of the major cities would be timely and meaningful. This study aims to provide a comparative study in operational system and planning contents of the Parks and Green Space Master Plan at urban scale. Sites include London, New York, Berlin, Sydney and Seoul. Analyses are focused on the master plans and strategy reports of each city. Frameworks for analysis are divided into operational system and planning contents. The results are as follows. First, the Parks and Green Space Plans as an open space planning linked to related resources would contribute to both integrated resources management and practice of the fairness. Second, evolution from quantity to quality of the parks and green space plan enhances revitalization and regeneration. Third, shift from the 'supply oriented plan' to 'need based plan' model provides flexible planning model to meet the demographic change, trend change, preference and use. Fourth, planning agents, enlarged opportunities for participation within each phase, diversified of the participants lead the changes from the passive participation to active one. In order to improve the practicability of the parks and green space master plan, a flexible planning strategy including social awareness changes and park governance is required.

• Journal of Technology Innovation
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• v.26 no.4
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• pp.29-56
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• 2018

The purpose of this research is to examine whether investment portfolio composition affects the technological performance of corporate venture capital (CVC). The stages of investment are categorized from "start-up/seed", "early", and "expansion", to "later" stage. We posit and test that the investment stage composition in a portfolio is highly correlated with the growth potential and downside risk of the portfolio, which in turn influences an investor's innovation performance. To test this hypothesis, we used negative binomial panel regression with 21 years of deal data from 70 cases of CVC. The results show that there is an inverted U shaped relationship between investment portfolio composition and technological performance. This means that the more seed or early stage investment within the investment portfolio, the higher the innovation performance; however, if the amount of seed or early stage investment is over a certain level, the performance decreases. Further, this study finds that the external partners of a venture negatively moderate the inverted U shaped relationship between portfolio composition and innovation performance. We believe that corporate planners, venture capitalists, and policy makers will be helped by these results showing that companies can maximize their investment performance by considering the investment stage and progress of investments.

• The Korean Journal of Food And Nutrition
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• v.10 no.4
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• pp.453-457
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• 1997

Sugars in Korean and Japanese pumpkin were studied. The sugars in pumpkin were crushed and extracted by boiling for 30 min. Korean pumpkin was found to contain 0.41% of sucrose, 0.54% of fructose, 0.61% of glucose and 0.68% of starch. Japanese pumpkin was found to contain 2.60% of sucrose, 2.76% of fructose, 1.91% of glucose and 1.22% of starch. No other mono- and oligosaccharides were detected in the test of TLC and HPLC. Starch in Japanese pumpkin showed only signal of $\alpha$-1,4-glucosidic linkage by proton NMR analysis, and showed 86% of absorbance by iodine reaction compared with amylose(DP 117). These results indicated that starch in Japanese pumpkin is composed by only amylose. Pectin contents of Korean and Japanese pumpkin sowed 6.29% and 2.67%, respectively, as galacturonic acid by carbazole analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.625-630
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• 2014

The amount of information is increasing rapidly with the development of the internet and the computer. Since these enormous information is managed by the document forms, it is necessary to search and process them efficiently. The document clustering technique which clusters the related documents through the similarity between the documents help to classify, search, and process the large amount of documents automatically. This paper proposes a method to find the initial seed points through principal component analysis when the documents represented by vectors in the feature vector space are clustered by K-means algorithm in order to increase clustering performance. The experiment shows that our method has a better performance than the traditional K-means algorithm.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.4 no.1
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• pp.18-27
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• 2001

Purpose: The aims of this study are to investigate the effect of the eradication of H. pylori on histological change of gastric mucosa in children with H. pylori gastritis and to determine whether the histological grading by the Sydney system is valuable in predicting the effect of treatment. Methods: 1) Histological scores by the Sydney system and the endoscopic characteristics were assessed before and at least four weeks after anti-H. pylori therapy in 42 children with H. pylori gastritis. 2) In 32 children treated with omeprazole, amoxicillin and clarithromycin (OAC), pretreatment histological scores and endoscopic findings were compared between the eradicated and the noneradicated to evaluate their predictive value for the successful eradication. Results: 1) In the eradicated (27 cases), nodular gastritis significantly decreased from 89% to 63% (p<0.05). There was an significant improvement in the mean activity score from 2.06 before treatment to 0.24 after treatment (p<0.01). The mean inflammatory score also improved from 2.61 before treatment to 1.89 after treatment (p<0.05). Lymphoid follicles significantly decreased from 48% to 15% (p<0.05). Epithelial damage improved in all 4 cases. But in the noneradicated (15 cases), there was no significant change in the frequency of nodular gastritis, the mean activity score, the mean inflammatory score and the frequency of the lymphoid follicles. 2) In 32 children treated with OAC, there was a tendency that the higher was the pretreatment score of the bacterial density, the lower was the eradication rate of H. pylori (p=0.072). Conclusion: The loss of the polymorphonuclear cell infiltration is the most prominent histological change after successful eradication. There may be negative correlation of the grade of the bacterial density with the success rate of the anti-H. pylori therapy.