• Title/Summary/Keyword: Study in Korea

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Identification of Ectomycorrhizal Fungi from Pinus densiflora Seedlings at an Abandoned Coal Mining Spoils

  • Park, Sang-Hyeon;Jeong, Hyeon-Suk;Lee, Yoo-Mee;Eom, Ahn-Heum;Lee, Chang-Seok
    • Journal of Ecology and Environment
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    • v.29 no.2
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    • pp.143-149
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    • 2006
  • This study was conducted to identify native ectomycorrhizal (ECM) fungi colonizing Pinus densiflora for revegetation of abandoned coal mines in Korea. Seedlings of P. densiflora growing on coal mining spoils of a study site in Samcheok were collected. ECM roots were observed under stereomicroscope and their DNA were extracted from each root tip for a seedling for molecular identification. A PCR primer pair specific to fungi, ITS1F and ITS4, was used to amplify fungal DNA. Restriction enzymes, Alul and Hinfl were used for restriction fragment length polymorphism (RFLP). Combined with RFLP profiles and sequence analysis, total twenty one taxa were identified from the ECM root tips. Basidiomycetous fungi including Thelephoraceae, Pezizales, Laccaria, Pisolithus and Ascomycetous fungi including ericoid mycorrhizal fungi were identified from this study. Results showed that the most frequently found in the study sites was a species in Thelephoraceae. A possible use of ECM fungi identified in this study for the revegetation of abandoned coal mines with P. densiflora was discussed.

A Study on Manufacturing Aggregation And Carbon Emission Intensity: Application of Spatial Panel Regression (국내 제조업 집적이 탄소 배출 강도에 미치는 영향: 공간패널회귀모형의 적용)

  • Zhen Wu;Hyun-Chung Kim
    • Korea Trade Review
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    • v.47 no.3
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    • pp.157-175
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    • 2022
  • This study calculates agglomeration indices of manufacturing specialization and diversification in different regions of South Korea. Two types of agglomeration indices are introduced into the spatial durbin model (SDM) to analyzes the effects of manufacturing agglomeration in Korea on CO2 emission intensity. The subjects of this study are 17 regions of South Korea , and the research period is from 2013 to 2019. This study also uses partial differential to analyze the direct and spillover effect of specialization and diversification agglomeration on CO2 emission intensity. From the perspective of direct effect, the results reveal that specialization agglomeration is an important factor contributing to Korea's CO2 emissions. However, diversification agglomeration has an obvious CO2 emission reduction effect. From the perspective of spillover effect, this study finds that specialization agglomeration in one region can also contribute to CO2 emissions in nearby regions. However, the development of diversification agglomeration in one region can have CO2 emission reduction spillover effect on neighboring regions.

Kinematical analysis of Yurchenko Streched at Horse Vaulting (도마운동 유리첸코 몸 펴 공중돌기 동작의 운동학적 분석)

  • Yoon, Chang-Sun;Kim, Tae-Sam;Yoon, Hee-Joung
    • Korean Journal of Applied Biomechanics
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    • v.13 no.3
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    • pp.67-79
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    • 2003
  • The purpose of this study is to investigate the effective skill motion through the kinematic analysis of the Yurchenko Streched motion in new horse vaulting. The subjects in this study were 3 male gymnasts who were ranked as national athletes. After the 3D motion analysis, kinematic variables were analyzed to comparison with the difference between this study and the previous study(Yang, D. Y and Lee, C. S, 1999). As a result, the following conclusions was drawn; 1. In the board contact phase, this study showed a shorten contact time to maintain in condition highly extension of hip and hee angle than the previous study. 2. In the pre-flight phase, this study appeared more shortly flight duration time and horizontal flight displacement than the previous study. 3. In the horse contact phase, the contact duration time and horizontal displacement of COG shortened than the previous study, but appeared to the fast horizontal and vertical velocity and highly extension of shoulder an. 4. In the post-flight phase, a stable horse contact appeared to the increase of the flight duration time and the apex height during the post-flight. And it showed that these results have a stable and good landing.

Toxicogenomics Study on ${\alpha}-Naphthylisothiocyanate\;(ANIT)$ Induced Hepatotoxictiy in Mice

  • Hwang, Ji-Yoon;Lim, Jung-Sun;Jeong, Sun-Young;Park, Han-Jin;Cho, Jae-Woo;Yoon, Seok-Joo
    • Molecular & Cellular Toxicology
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    • v.2 no.1
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    • pp.48-53
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    • 2006
  • [ ${\alpha}-Naphthylisothiocyanate$ ] (ANIT) induces intrahepatic cholestasis, involving damage to biliary epitheial cells. This study investigates hepatic gene expression and histopathological alterations in response to ANIT treatment in order to elucidate early time response of ANIT-induced hepatotoxicity. ANIT was treated with single dose (3, 6, and 60 mg/kg) in corn oil by oral gavage. Serum biochemical and histopathological observation were performed for evaluation of hepatotoxicity level. Affymetrix oligo DNA chips were used for gene expression profile by ANIT-induced hetpatoxicity. Hepatic enzyme levels (ALT, AST, and ALP) were increased in 24 hr high dose group. In microscopic observations, moderate hepatocellular necrosis, were confirmed 24 hr high dose groups. We found that gene expression patterns were dependent on time and dose. Our selected genes were related inflammation and immunomodulation. In this study, ANIT-induced hepatotoxicity was involved in acute phase responses and provides evidence for role of neutrophil could be mechanism associated with ANIT-mediated hepatotoxicity.

A Study on Comparison of Lung Cancer Prediction Using Ensemble Machine Learning

  • NAM, Yu-Jin;SHIN, Won-Ji
    • Korean Journal of Artificial Intelligence
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    • v.7 no.2
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    • pp.19-24
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    • 2019
  • Lung cancer is a chronic disease which ranks fourth in cancer incidence with 11 percent of the total cancer incidence in Korea. To deal with such issues, there is an active study on the usefulness and utilization of the Clinical Decision Support System (CDSS) which utilizes machine learning. Thus, this study reviews existing studies on artificial intelligence technology that can be used in determining the lung cancer, and conducted a study on the applicability of machine learning in determination of the lung cancer by comparison and analysis using Azure ML provided by Microsoft. The results of this study show different predictions yielded by three algorithms: Support Vector Machine (SVM), Two-Class Support Decision Jungle and Multiclass Decision Jungle. This study has its limitations in the size of the Big data used in Machine Learning. Although the data provided by Kaggle is the most suitable one for this study, it is assumed that there is a limit in learning the data fully due to the lack of absolute figures. Therefore, it is claimed that if the agency's cooperation in the subsequent research is used to compare and analyze various kinds of algorithms other than those used in this study, a more accurate screening machine for lung cancer could be created.

An Empirical Study of Cost Structure in Telecommunication Industry (국내 전기통신산업의 비용구조에 관한 실증연구)

  • 이덕주;오형석
    • Journal of the Korean Operations Research and Management Science Society
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    • v.22 no.2
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    • pp.169-180
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    • 1997
  • In this study, we estimate the multi-service cost function of Korea Telecom in order to characterize the cost structure of the telecommunication industry in Korea. By examining the cost function of Korea Telecom, we show that telecommunication costs of Korea Telecom are subadditive. Therefore, we conclude that a natural monopoly exists in the telecommunication industry in Korea.

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Effective Implementation of Environmental Impact Assessment (환경영향평가 제도의 활성화 방안)

  • 장준기
    • Journal of environmental and Sanitary engineering
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    • v.8 no.1
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    • pp.29-47
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    • 1993
  • The purpose of this study is to improve institution of EIA(Environmenta1 Impact Assessment) in Korea. For this study, institution of EIA in Korea and other countries and copies of EIS prepared in Korea were analyzed. As a result, improvements of EIA should require introducing EIA in projects and planning level, building environmental information system, estimating appropriate costs of EIS preparation.

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A Cross-Country Comparative Study on the Effect of Online Review Search on Purchase Satisfaction of Existing Buyers (온라인 후기 탐색이 기존 구매자의 구매 만족도에 미치는 영향의 국가 간 비교연구)

  • Qin, PengFei;Kwon, Sundong
    • Journal of Information Technology Applications and Management
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    • v.27 no.6
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    • pp.53-73
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    • 2020
  • Many prior studies have been conducted that positive reviews increase the intention to purchase. However, there are very few papers that have studied the impact of review search on purchase satisfaction. It is meaningful to study the impact of review search on purchase satisfaction as it can lead the business successfully by inducing repurchase. There is also no study of how review search have different effects on purchase satisfaction among countries. Given the growing number of cross-border e-commerce, we believe that the need for research is high because identifying these differences between countries can have a very important impact on a company's successful overseas expansion. Therefore, in this study, the impact of positive and negative review search on purchase satisfaction and the national impact were set up as a research model. In order to verify this research model, the survey was distributed to those who experienced online purchase in Korea and China, and a total of 234 copies were collected, including 125 copies in Korea, 109 copies in China, and the research model was verified using Smart-PLS structural equation analysis tools. First, positive review search has been shown to positively affect purchase satisfaction. Second, it has been shown that negative review search also has a positive effect on purchase satisfaction. Third, the impact of positive and negative review search on purchase satisfaction was different between Korea and China. While Korea is more aggressive in review search than China due to its high tendency to avoid uncertainty, China is less likely to avoid uncertainty than Korea and is more likely to rely on brand familiarity. Therefore, according to the uncertainty avoidance moderation effect the impact of positive and negative review search on purchase satisfaction was higher in Korea than in China. In this study, Shopping mall managers need to take strategic measures to maximize shopping mall performance by recognizing positive aspects of negative review search on purchase satisfaction. Companies and managers in Korea and China can establish strategies to promote product sales when companies enter the global market.

A Study on Growing Needs for Adult Day Service Center in Seoul under the New Longterm Care System (노인수발보장제도 도입에 따른 노인주간보호시설의 수요증가와 시설변화에 관한 연구)

  • Oh, Eun-Jin;Park, Hae-Sun
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.12 no.2
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    • pp.41-50
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    • 2006
  • Introduction of new longterm care policy for elderly in Korea would change many aspects of elderly care service facilities. Especially elderly home care services like adult daycare centers will expand drastically after beginning of longterm care insurance. The purpose of this study is to estimate demand of adult daycare centers by comparing with the U.S and Japanese cases. Korean government is expecting that adult daycare centers will expand ten times within 4 years. This estimate is exceeding the facility demand estimate of the U.S. and Japan. The results of population study and expecting growth rate of adult daycare centers in Seoul indicate that more than 300 centers, 4 times of the number of existing centers, are in need based on Seoul elderly population in 2004. To supply these numbers of facilities in short period, more in depth study should be followed. Existing adult daycare facilities' in Seoul were analyzed by their building and management types. Interior spaces of adult daycare centers in Korea are similar to the U.S. and Japan in space arrangements but much smaller in size. In depth study of space programming as well as overall demand survey of adult daycare centers is urgently in need for more realistic expansion of adult daycare centers.

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Attitude and awareness of Sasang Constitution Investigators on the Informed Consent (체질의학 임상연구자의 피험자 동의서 취득에 대한 인식도 조사)

  • Yoo, Jong-Hyang;Kim, Yun-Young;Kwon, Ji-Hye;Park, Ki-Hyun;Lee, Si-Woo
    • Journal of Sasang Constitutional Medicine
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    • v.23 no.3
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    • pp.318-329
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    • 2011
  • 1. Objectives: We surveyed the attitude and awareness of Sasang Constitution investigators on informed consent in clinical study. This study was performed in order to improve the quality of ethical aspects in clinical study by surveying the process of obtaining informed consent. 2. Methods: We sent the questionnaire by email to Sasang Constitution investigators who had the experience in clinical study. The question was about the necessity of informed consent and the process of obtaining it. 3. Results: Twenty-two out of 24 questionnaires were collected. All of investigators recognized that informed consent is needed for clinical study. Sixty-four percent of the respondents 'fully' or 'mostly' explained the informed consent but they added only 41% of participants 'fully' or 'mostly' understood. Fifty-four point five percent of respondents provided participants enough time and opportunity to inquire the study in details to decide whether or not to participate in the study, the rest of respondents obtained informed consent without providing enough time for decision. 4. Conclusions: Sasang Constitution investigators had high awareness of necessity for informed consent in clinical study. But participants' understanding was low despite of the degree of investigators' explanation. A various strategies should be designed for improving consent forms and process. Most of all, investigators should make sure that informed consent intends to protect participants and promote ethical research conduct.