• 제목/요약/키워드: Previous Studies

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構造変動期の日朝関係と韓国-南北関係との因果性に注目 しながら (Japan-DPRK relations during the structural change period and Korea's response - Focusing on causality with the inter-Korean relationship)

  • Park, Jungjin
    • 분석과 대안
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    • 제2권1호
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    • pp.107-125
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    • 2018
  • This paper aims to elucidate the historical significance and issues about DPRK-Japan relations in terms of the Korean Peninsula-Japan relations. The first issue is the 'Treaty on Basic Relations between Japan and the Republic of Korea', and DPRK-Japan relations during the Cold War. The Relations Order between the Korean Peninsula and Japan, of 1965 ("65 Order), was closely linked with inter-Korean relations. The second issue is a critical re-interpretation of previous studies on the Stockholm agreement. Previous studies have focused on analyzing the question "Why did North Korea and Japan agree to Stockholm?", In other words, what was the intention of North Korea and Japan in Stockholm? This paper adds to raise the question of "How Did the Stockholm can be agreed?", to critically review the analysis performed by the previous studies. Through the analysis of this question, this paper reveals that the relationship between North Korea and Japan is on the qualitative change. And, based on this analysis, this paper argue that the South Korean government should attempt more active engagement and deploy more comprehensive approach to improve the relationship between North Korea and Japan.

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원전 기기 용접 잔류응력 평가 연구 고찰 (Investigation on the Studies for Welding Residual Stresses in Nuclear Components)

  • 김종성
    • 한국압력기기공학회 논문집
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    • 제12권1호
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    • pp.30-40
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    • 2016
  • The paper investigates the previous studies about welding residual stresses in nuclear components. First, various residual stress measurement methods are reviewed in applicability. Second a finite element welding residual stress analysis technique, which was developed from the viewpoint of FFS (Fitness-For-Service) assessment, is explained. Third, characteristics of the welding residual stresses on J-groove welds and butt welds were presented via investigating the previous studies. Last, engineering formulae for residual stresses in the FFS assessment codes such as R6 and API 579/ASME FFS-1 Code is summarized.

기업의 R&D 성과 측정 : 산업간 차이에 대한 탐색적 연구 (Measuring Firms' R&D Performance: an exploratory study on sectoral differences in R&D performance)

  • 김승겸;이학연;박용태
    • 기술경영경제학회:학술대회논문집
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    • 기술경영경제학회 2006년도 제28회 동계학술발표회 논문집
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    • pp.5-20
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    • 2006
  • An efficient and productive R&D operation is a major source of competitive advantage in today's economy, and a lot of efforts are made to raise R&D productivity. A prerequisite for making R&D more efficient and productive is to be able to measure it. Hence, a number of studies have attempted to measure R&D productivity. R&D productivity, in the previous studies, was measured with patents at the firm or industry level. However, most previous studies considered only a quantitative aspect, not a quantitative aspect of patents. In this study, various dimensions of patent quality as well as patent quantity were considered for the measurement of R&D performance. The differences in R&D performance across sectors were examined, and it was found that electrical/electronic industry shows higher R&D performance than mechanic and chemical industries. Discriminant analysis based on inputs and outputs for R&D shows' that there exist a strong discriminatory power across industries. The results of this research can provide the directions 'for the firm's R&D policy.

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Research history of Nannophya Rambur(Odonata: Libellulidae): A recently discovered species in addition to Nannophya koreana Bae in Korea

  • Kim, Dong Gun
    • 환경생물
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    • 제38권2호
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    • pp.308-314
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    • 2020
  • The Nannophya species in Korea was thought to consist of only Nannophya pygmaea. Previous studies on the species, including life history and development, conservation and restoration, habitat characteristics, genetic studies, distribution, behavior, and taxonomy have been conducted. However, a new Nannophya species, Nannophya koreana, was recently discovered in Korea. Moreover, this new species was found to inhabit both Korea and Japan. Thus, the previous studies should be reevaluated in relation to the new species, Nannophya koreana, and the latter should be treated as an endangered species worldwide given the current population instability.

In vitro excystation of metacercarial cysts of Echinostoma trivolvis from Rana species tadpoles

  • Fried, Bernard;Bradford, J.-David
    • Parasites, Hosts and Diseases
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    • 제35권2호
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    • pp.75-78
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    • 1997
  • In uitro excystation studies were done on the metacercarial cysts of Echinostomn triuolvis obtained from the kidneys of naturally infected Rnna species tadpoles. Cysts were excysted in an alkaline trypsin-bile salts medium and the percentage of excystation was compared with that from previous studies done on cysts obtained from the kidneys of snails. The percentage of excystation of E. triuoluis metacercariae from tadpole kidneys was similar to that reported for previous studies on cysts obtained from experimentally infected gastropod hosts. The possible role of tadpoles as an agent for the transmission of Echinostomn and echinostomiasis to humans is discussed.

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A simplified evaluation method of skeleton curve for RC frame with URM infill

  • Jin, Kiwoong;Choi, Ho
    • Earthquakes and Structures
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    • 제13권3호
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    • pp.309-322
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    • 2017
  • In this paper, a simplified evaluation method of the skeleton curve for reinforced concrete (RC) frame with unreinforced masonry (URM) infill is proposed in a practical form, based on the previous studies. The backbone curve for RC boundary frame was modeled by a tri-linear envelope with cracking and yielding points. On the other hand, that of URM infill was modeled by representative characteristic points of cracking, maximum, and residual strength; also, the interaction effect between RC boundary frame and the infill was taken into account. The overall force-displacement envelopes by the sum of RC boundary frame and URM infill, where the backbone curves of the infill from other studies were also considered, were then compared with the previous experimental results. The simplified estimation results from this study were found to almost approximate the overall experimental results with conservative evaluations, and they showed much better agreement than the cases employing the infill envelopes from other studies.

Methodological Challenges of Empirical Studies on Government-Nonprofit Service Delivery: Toward a Dynamic Approach

  • 조성숙
    • 한국시스템다이내믹스연구
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    • 제9권1호
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    • pp.199-218
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    • 2008
  • Empirical studies have shown that government and human service nonprofit organizations have maintained active partnerships to deliver human services for the past several decades. However, the previous researches on resource dependent government-nonprofit service delivery have revealed serious methodological limitations to adequately demonstrate the dynamic relationship between both sectors over time. Since the dynamics underlying the government-nonprofit service delivery is a complex process, in which multiple factors dynamically interact over time, the assumptions of system dynamics can help improve these methodological drawbacks. This study aims to explore methodological issues and weaknesses observed in empirical studies on resource dependent government-nonprofit service delivery in the United States, and further attempts to provide insights on future research toward a dynamic approach, bringing the assumptions of system dynamics to the challenges of the previous researches.

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The Relationship between Parental Physical Affection and Child Physical Aggression among Japanese Preschoolers

  • Katsurada, Emiko
    • Child Studies in Asia-Pacific Contexts
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    • 제2권1호
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    • pp.1-10
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    • 2012
  • The present study, based on Tiffany Field's model of violence and intimacy as well as other previous research, examines the relationship between parents' physical affection and their child's aggressive behavior. One hundred seventy-five mothers and 124 fathers of Japanese preschoolers answered a questionnaire that included a parental physical affection scale developed for this study. Children's aggressive behaviors were rated by their teachers on the hostile-aggressive subscale of the Preschool Behavior Questionnaire. Consistent with Field's model and previous studies, the results of logistic regression analyses indicated that children who received more physical affection from mothers or fathers during daily parenting were less likely to be aggressive at preschool. When the mother's and the father's physical affection scores were simultaneously entered in the equation, only the father's score was significant. Implications and limitations of the research are discussed.

Quinones (menadione, benzoquinone, 및 2,3-dimethoxy-1,4-naphthoquinone)의 혈소판 세포독성 (Effects of Various Quinones (Menadione, Benzoquinone and 2,3-Dimethoxy-1,4-naphthoquinone) on Rat Platelets)

  • 승상애;이무열;이주영;김미정;정진호
    • Toxicological Research
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    • 제12권2호
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    • pp.289-293
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    • 1996
  • Our previous studies demonstrated that quinone (menadione) is cytotoxic to rat platelets. In an attempt to assess the relative contributions of redox cycling and/or arylation in quinone-induced cytotoxicity, we have studied three quinones with different mechanisms: 2, 3-dimethoxy-1, 4-naphthoquinone (DMNQ; pure redox cycler), menadione (both redox cycler and arylator), and 1, 4-benzoquinone (pure arylator). The order of redox cycling capacity in platelet rich plasma (PRP) isolated from rats was menadione>DMNQ>1, 4-benzoquonone, which was consistent with the previous studies using isolated hepatocytes. 1, 4-Benzoquinone was more toxic to rat platelets than menadione, while DMNQ did not cause cell death at all. Lactate dehydrogenase inhibition studies revealed that 1, 4-benzoquinone inhibited significantly in a time-dependent manner, while menadione and DMNQ did not at all. These results suggested that arylation by quinone compounds might play a critical role in quinone-induced cytotoxicity in rat platelets.

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Storing Digital Information in Long-Read DNA

  • Ahn, TaeJin;Ban, Hamin;Park, Hyunsoo
    • Genomics & Informatics
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    • 제16권4호
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    • pp.30.1-30.6
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    • 2018
  • There is urgent need for effective and cost-efficient data storage, as the worldwide requirement for data storage is rapidly growing. DNA has introduced a new tool for storing digital information. Recent studies have successfully stored digital information, such as text and gif animation. Previous studies tackled technical hurdles due to errors from DNA synthesis and sequencing. Studies also have focused on a strategy that makes use of 100-150-bp read sizes in both synthesis and sequencing. In this paper, we a suggest novel data encoding/decoding scheme that makes use of long-read DNA (~1,000 bp). This enables accurate recovery of stored digital information with a smaller number of reads than the previous approach. Also, this approach reduces sequencing time.