• Title/Summary/Keyword: 연쇄

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Syntheses of 70% Solids Acrylic Resin and Comparative Study in Physical Properties as Acrylic Urethane Resin Coatings (고형분 70% 아크릴수지 합성과 아크릴-우레탄 도료의 도막물성 비교 연구)

  • Kim, Seong-Kil;Park, Hyong-Jin
    • Journal of the Korean Applied Science and Technology
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    • v.38 no.2
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    • pp.476-487
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    • 2021
  • To prepare acrylic resin coatings containing 70% of solids, we used n-butyl methacrylate(BMA), methyl methacrylate(MMA), 2-hydroxyethyl methacrylate(2-HEMA), and acetoacetoxyethyl acrylate(AAEA), caprolactone acrylate(CLA) as raw materials, the glass transition temperature(Tg) of acrylic copolymer was adjusted around 50 ℃. The viscosity and molecular weight of the acrylic resins was increased with increasing OH values. Di-tert-amyl peroxide was found to be the suitable initiator to get high-solids acrylic resins. The optimum reaction conditions found in the study are 5 wt% of initiator, 4 wt% of chain transfer agent, 4 hrs of dropping time, and 140 ℃ of reaction temperature. The structure of the synthesized resins were characterized by FT-IR and 1H-NMR spectroscopy. Number average molecular weight of 1900~2600 and molecular wight distribution of 1.4~2.1 were obtained. Crosslinked acrylic urethane clear coatings were obtained by curing reaction between the synthesized acrylic resins and hexamethylene diisocyanate trimer(Desmodur N-3300), the equivalent ratio of NCO/OH was 1.2/1.0. The physical properties from the following studies were carried out: viscosity(Zahn cup #2), adhesion, drying time, pot-life, pensil hardness, and 60° specular gloss. Various properties of the acrylic urethane clear coatings were also evaluated on the coating specimens. Adhesion property to a substrate, drying time, pot-life, pencil hardness, and 60° specular gloss of prepared paint showed quite good properties. Futhermore, prepared paint containing 10% of CLA showed quite good properties for adhesion, low viscosity and high hardness.

A Study on the Changes in Perspectives on Unwed Mothers in S.Korea and the Direction of Government Polices: 1995~2020 Social Media Big Data Analysis (한국미혼모에 대한 관점 변화와 정부정책의 방향: 1995년~2020년 소셜미디어 빅데이터 분석)

  • Seo, Donghee;Jun, Boksun
    • Journal of the Korea Convergence Society
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    • v.12 no.12
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    • pp.305-313
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    • 2021
  • This study collected and analyzed big data from 1995 to 2020, focusing on the keywords "unwed mother", "single mother," and "single mom" to present appropriate government support policy directions according to changes in perspectives on unwed mothers. Big data collection platform Textom was used to collect data from portal search sites Naver and Daum and refine data. The final refined data were word frequency analysis, TF-IDF analysis, an N-gram analysis provided by Textom. In addition, Network analysis and CONCOR analysis were conducted through the UCINET6 program. As a result of the study, similar words appeared in word frequency analysis and TF-IDF analysis, but they differed by year. In the N-gram analysis, there were similarities in word appearance, but there were many differences in frequency and form of words appearing in series. As a result of CONCOR analysis, it was found that different clusters were formed by year. This study confirms the change in the perspective of unwed mothers through big data analysis, suggests the need for unwed mothers policies for various options for independent women, and policies that embrace pregnancy, childbirth, and parenting without discrimination within the new family form.

An Economic Ripple Effect Analysis of National Science & Technology Information Service : Focusing An Input-Output Analysis (국가과학기술지식정보서비스의 경제적 파급효과에 관한 연구 : 산업연관분석을 중심으로)

  • Park, Sung-Uk
    • Journal of Korea Technology Innovation Society
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    • v.21 no.4
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    • pp.1296-1312
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    • 2018
  • The wave of the Fourth Industrial Revolution was spreaded in Moon Jae-in Government. The efficiency of the R&D budget of government began to pay attention, the role of the National Science & Technology Information Service (NTIS) which provides all national R&D information in real time World's first R&D information portal has been emphasized. NTIS provides information on national R&D projects with their participating researchers, outcomes, and facilities & equipment through of information from each ministry and institution. NTIS supports to build science and technology policies, to enable transparent and efficient management of national R&D projects and to promote joint utilization of the R&D data among researchers and industrial utilization of the R&D data. NTIS provides since 2005. In this paper, I have analyzed the economic ripple effect of NTIS using the Input-Output model technique based on the input-output tables published by the Bank of Korea. When I set the NTIS R&D budget (about 120M$ for the last 13 years) as input coefficients, the effect on production inducement, value added inducement and employment inducement was analyzed by 211M$, 100M$ and 1,882 respectively.

Application of Molecular Diagnostics Technology in the Development of a Companion Diagnostics for Malignant Solid Tumors (악성 고형암의 항암제 동반진단 기술에서 분자진단기술의 적용)

  • Kim, Jin-Hee
    • The Journal of the Korea Contents Association
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    • v.19 no.3
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    • pp.365-374
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    • 2019
  • Unlike benign tumors, malignant tumors are capable of metastasis, easy to relapse, poor survival, and low quality of life. In Korea, here is a tendency to treat the tumors collectively according to the General Principles of Cancer Chemotherapy(GPCC) of the Health Insurance Review & Assessment Service (HIRA). But recently, companion diagnostics(CDx) is recommended rather than unilateral medication because biomarker-based molecular diagnostics is possible to predict the drug response of patients before drug treatment. Not only domestic but also overseas Food and Drug Administratio (FDA) recommends the development of the CDx system at the stage of drug development to ensure the responsiveness and safety of medicines. In this study, I focused on the necessity of CDx development direction as well as CDx development status through literature review. Furthermore I also discussed CDx types according to the molecular diagnostic technology such as immunohistochemistry (IHC), polymerase chain reaction (PCR), in situ hybridization (ISH), and next-generation sequencing (NGS) not only in the approved CDx but also in the developing one by US FDA. And I suggested the technology issue of CDx development process such as a selection of molecular diagnostics at the time of release, a clear understanding of the CDx mechanism, and a convergence of drug with CDx development. The necessity of social insurance system also was proposed for CDx development.

Korea Service Insensity and Economic Growth in Korea Economy (한국 경제의 서비스화와 생산성: 중간재 생산자 서비스와 비생산자 서비스의 비교를 중심으로)

  • Seok, Jun-Ho;Kim, Soo-Eun;Kim, Chul
    • International Area Studies Review
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    • v.15 no.2
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    • pp.125-150
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    • 2011
  • As the economy grows, there is a concern that the economic development causes a productivity reduction because of the service intensive growth. However, the economy of developed countries encounter with the productivity growth as their economy grows, which phenomenon called Baumol's paradox. Oulton (1999, 2001) find out the reason of Baumol's paradox in a forward and backward chain effects. So, this paper is aimed at verifying the theory of Oulton (1999, 2001). Moreover, we test the difference effect between a consumer service and producer service input using a dummy variable. We use the Input-Output Table (1990, 1995, 2000, 2005) that is offered by the Bank of Korea to accomplish the purpose of our research that is represented above. We find out that the Korea's intermediate producer service inputs cause a multifactor productivity growth. That result is matched with the Oulton (1999, 2001)'s theory. But, the intermediate consumer service inputs don't have a significant effect on a multifactor productivity. The result of verifying the effect of intermediate producer service inputs among industries shows that the effects on manufacture industries are less than other industries.

Is Genotypic Resistance-guide Eradication Therapy Effective for Patients with Refractory Helicobacter pylori Infection? (불응성 Helicobacter pylori 감염 환자들에게 유전자형 내성을 기반한 제균 치료는 유용한가?)

  • Kim, Sung Eun
    • The Korean journal of helicobacter and upper gastrointestinal research
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    • v.18 no.4
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    • pp.277-279
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    • 2018
  • 전 세계적으로 Helicobacter pylori의 항생제 내성률은 지속적으로 증가하고 있으며, 기존의 제균 치료에 실패한 H. pylori 감염 환자들에 대한 효과적인 구제요법(rescue therapy)의 필요성 역시 증가하고 있다. 이 연구는 두 개 기관, 공개, 평행 그룹, 무작위 배정 연구로서 불응성 H. pylori 감염 환자들의 구제요법으로 유전자형 내성을 기반한 치료(genotype resistance-guided therapy)와 경험적 치료(empirical therapy) 중 어느 것이 보다 효과적인지를 비교하고자 하였다. 2012년 10월부터 2017년 9월까지 20세 이상의 불응성 H. pylori 감염 환자들을 대상으로 하였으며, 불응성 H. pylori 감염은 과거 두 종류 이상의 H. pylori 제균 치료를 받았음에도 불구하고 H. pylori 제균에 실패한 환자들로 정의하였다. 이들에게서 한 군은 14일간의 유전자형 내성을 기반한 순차 치료(n=21 in trial 1, n=205 in trial 2)를, 다른 한 군은 환자들의 과거 제균 치료 종류를 감안한 14일간의 경험적 순차 치료(n=20 in trial 1, n=205 in trial 2)를 시행하였다. 순차 치료법은 첫 7일은 esomeprazole 40 mg과 amoxicillin 1 g을 하루 두 번 복용한 다음, 나머지 7일은 esomeprazole 40 mg과 metronidazole 500 mg, 그리고 1) levofloxacin 250 mg 또는 2) clarithromycin 500 mg 또는 3) tetracycline 500 mg을 하루 두 번 복용하는 것으로 구성하였다. 23S ribosomal RNA (rRNA)나 gyrase A에 대한 내성 관련 돌연변이 여부는 direct sequencing을 통한 중합효소연쇄반응(polymerase chain reaction, PCR) 검사를 이용하였고, 제균 성공 여부는 요소호기검사를 통해 확인하였다. 일차 결과 지표는 치료 방법에 따른 제균율로 정하였다. Trial 1에서는 tetracycline 대신 doxycycline 100 mg을 사용하였는데, 제균 성공률이 유전자형 내성을 기반한 치료군에서는 17명(81%), 경험적 치료군에서는 12명(60%)으로 나타났다(P=0.181). 하지만, 다른 순차 치료군들과 비교하였을 때, doxycycline을 포함한 순차 치료군의 제균율이 현저히 낮은 것으로 나타나서(15/26, 57.7%) doxycycline을 포함한 순차 치료법은 종결하기로 하고, trial 2부터는 doxycycline 대신 tetracycline으로 교체하여 연구를 지속하였다. Trial 2의 intention-to-treat (ITT) 분석 결과, 유전자형 내성을 기반한 치료군에서는 160/205명(78%), 경험적 치료군에서는 148/205명(72.2%)으로 두 그룹 간의 통계적인 제균율의 차이는 보여주지 못하였다(P=0.170). 부작용 및 환자 순응도에서도 양 군 간의 의미 있는 차이는 없었다. 따라서, 두 종류 이상 H. pylori 제균 치료에 실패한 환자들이라고 할지라도 기존의 제균 치료력을 바탕으로 적절한 경험적 치료를 시행하는 것은 유전자형 내성을 기반한 치료 정도의 효과는 있으며 접근성, 비용, 환자들의 선호도 등의 여러 가지 부가적인 사항들을 고려할 때, 제균 치료력을 고려한 경험적 치료는 간단한 수준의 유전자형 내성을 기반한 치료의 대안으로 받아들여질 수 있을 것으로 제안하였다.

Effect of Organic Waste Application on Soil Chemical Properties and Organisms under Zelkova serrata Cultivation (유기성폐기물이 느티나무 재배지 토양의 화학성 및 생물에 미치는 영향)

  • Eo, Jinu;Kim, Myung-Hyun;Nam, Hyung-kyu;Kwon, Soon-Ik;Song, Young-Ju
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.471-478
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    • 2018
  • The purpose of this study was to investigate effects of reusable organic wastes, on soil organisms and chemical properties. Bone meal, de-oiled cake, and oyster shell were applied and abundances of soil organisms were measured at 3 and 15 months, after treatment in soil under sawleaf zelkova cultivation. Soil organisms are affected, by the quality of applied organic wastes. Abundance of microorganisms was higher in oyster shell treated soils than in untreated soils, suggesting that soil pH is a driving force, altering abundance and structure of the microbial community. Increase in abundance of bacterivorous nematodes was observed under treatment with bone meal and de-oiled cake, but there was slight change in abundance of fungivorous and herbivorous nematodes. Abundance of herbivorous nematode was positively correlated with plant growth, at 15 months after treatment. Response of microarthropods in the Collembola and Oribatida was not apparent. Abundances of primary consumers were not significantly correlated with microorganisms. This study suggested that organic waste influences soil organisms primarily by altering soil chemical properties and bottom-up effects may not occur in trophic reactions.

Analysis and Verification of Ancient DNA (고대 DNA의 분석과 검증)

  • Jee, Sang-hyun;Seo, Min-seok
    • Korean Journal of Heritage: History & Science
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    • v.40
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    • pp.387-411
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    • 2007
  • The analysis of ancient DNA (aDNA) has become increasingly considerable anthropological, archaeological, biological and public interest. Although this approach is complicated by the natural damage and exogenous contamination of a DNA, archaeologists and biologists have attempted to understand issues such as human evolutionary history, migration and social organization, funeral custom and disease, and even evolutionary phylogeny of extinct animals. Polymerase chain reaction(PCR) is powerful technique that analyzes DNA sequences from a little extract of an ancient specimen. However, deamination and fragmentation are common molecular damages of aDNA and cause enzymatic inhibition in PCR for DNA amplification. Besides, the deamination of a cytosine residue yielded an uracil residue in the ancient template, and results in the misincorporation of an adenine residue in PCR. This promotes a consistent substitution (cytosine thymine, guanine adenine) to original nucleotide sequences. Contamination with exogenous DNA is a major problem in aDNA analysis, and causes oversight as erroneous conclusion. This report represents serious problems that DNA modification and contamination are the main issues in result validation of aDNA analysis. Now, we introduce several criterions suggested to authenticate reliance of aDNA analysis by many researchers in this field.

The Study on the modernism characteristics of melodrama in the 1930s (1930년대 멜로드라마의 모더니즘적 특성 연구)

  • Sim, Sang-gyo
    • (The) Research of the performance art and culture
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    • no.35
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    • pp.203-227
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    • 2017
  • In this thesis, I examined the characteristics of modernism in this work, focusing on the melodrama "Sarang ye soggo donye wulgo(means 'Crying in Love and Crying for Money')", which was popular in the 30s when the consciousness of modernity was overflowing. There has never been an example of a connection between modernism and drama in the 1930s. The characteristic of modernism is clearly embedded in the representative drama of "Sarang ye soggo donye wulgo(means 'Crying in Love and Crying for Money')" at that time. In the title "Sarang ye soggo donye wulgo(means 'Crying in Love and Crying for Money')". 'Don' reveals modern elements. 'Love' can be seen as revealing melodramatic elements. The flair of modern art, which is a background to reveal modern elements, is spread throughout the works. Hongdo fails to complete the relationship with his family, as well as with the couple. It became a person who accepted the modernistic phenomenon by showing the domination of matter. While the typical method of constructing conflicts in the pre-modern narrative works is horizontal and sequential, it can be said that it was in the form of a train station, while the post-modern era of narrative conflict formation from the 30s forms a plurality of conflicts simultaneously, can do. The fear of the ordinary people who see the reality that urban and western values are already rampant by attempting new contents that lead the change of values in "Sarang ye soggo donye wulgo(means 'Crying in Love and Crying for Money')" became a factor to transfer into internal conflict again.

Development of Ultra-Rapid Reverse-Transcription PCR for the Rapid Detection against Slow Bee Paralysis Virus (SBPV) (Slow Bee Paralysis Virus (SBPV) 신속 검출을 위한 초고속 역전사 중합효소 연쇄반응법의 개발)

  • Kim, Somin;Lim, Sujin;Kim, Jungmin;Lim, Yoon-Kyu;Yoon, Byoungsu
    • Journal of Apiculture
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    • v.32 no.3
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    • pp.171-180
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    • 2017
  • Slow Bee Paralysis Virus (SBPV) is a pathogenic virus against honeybee and bumblebee, causes the death of adult bee by paralyzing the fore-leg of bee. In this study, for rapid detection of SBPV from bumblebee, SBPV-specific Ultra-rapid Reverse transcription PCR was developed. After optimizing of SBPV-specific Ultra-rapid PCR, the existence of $1.0{\times}10^8$ SBPV-specific DNA molecules could be recognized in 3 minute and 35 seconds. Even $1.0{\times}10^1$ molecules of SBPV-specific DNA could be measured with quantitative manner. Meanwhile, from both imported bumblebee and bumblebee produced in Korea, SBPV were detected using proposed method. In the laboratory as well as in the field, SBPV-specific Ultra-rapid Reverse transcription PCR would be applied and might be expected as useful tools at production of bumblebee or inspection for the import and export system of bumblebee.