• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.3-6
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• 2001

In common globular proteins, the native form is in its most stable state. However, the native form of inhibitory serpins (serine protease inhibitors) and some viral membrane fusion proteins is in a metastable state. Metastability in these Proteins is critical to their biological functions. Our previous studies revealed that unusual interactions, such as side-chain overpacking, buried polar groups, surface hydrophobic pockets, and internal cavities are the structural basis of the native metastability. To understand the mechanism by which these structural defects regulate protein functions, cavity-filling mutations of ${\alpha}$1-antitrypsin, a prototype serpin, were characterized. Increasing conformational stability is correlated with decreasing inhibitory activity. Moreover, the activity loss appears to correlate with the decrease in the rate of the conformational switch during complex formation with a target protease. We also increased the stability of ${\alpha}$1-antitrypsin greatly via combining various stabilizing single amino acid substitutions that were distributed throughout the molecule. The results showed that a substantial increase of stability, over 13 kcal/mol, affected the inhibitory activity with a correlation of 11% activity loss per kcal/mol. The results strongly suggest that the native metastability of proteins is indeed a structural design that regulates protein functions and that the native strain of e 1-antitrypsin distributed throughout the molecule regulates the inhibitory function in a concerted manner.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.252-255
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• 2004

반도체는 high integrated, high speed, low power를 위하여 design 뿐만 아니라 재료 측면에서도 많은 변화를 가져오고 있으며, RC delay time을 줄이기 위하여 Al 배선보다 비저항이 낮은 Cu와 low-k material 적용이 그 대표적인 예이다. 그러나, Cu 배선의 경우 dry etching이 어려우므로, 기존의 공정으로는 그 한계를 가지므로 damascene 또는 dual damascene 공정이 소개, 적용되고 있다. Damascene 공정은 절연막에 photo와 RIE 공정을 이용하여 trench를 형성시킨 후 electrochemical plating 공정을 이용하여 trench에 Cu를 filling 시킨다. 이후 CMP 공정을 이용하여 절연막 위의 Cu와 barrier material을 제거함으로서 Cu 배선을 형성하게 된다. Dual damascene 공정은 trench와 via를 동시에 형성시키는 기술로 현재 대부분의 Cu 배선 공정에 적용되고 있다. Cu CMP는 기존의 metal CMP와 마찬가지로 oxidizer를 이용한 Cu film의 화학반응과 연마 입자의 기계가공이 기본 메커니즘이다. Cu CMP에서 backside pressure 영향이 uniformity에 미치는 영향을 살펴보았으며, electrochemical plating 공정에서 발생하는 hump가 CMP 결과에 미치는 영향과 dishing 결과를 통하여 그 영향을 평가하였다.

• Corrosion Science and Technology
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• 제18권2호
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• pp.39-48
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• 2019

The feasibility of using benzotriazole (BTAH) to inhibit pitting corrosion in the sprinkler copper tubes was investigated by filling the tubes with BTAH-water solution in 829 households at an eight-year-old apartment complex. The water leakage rate was reduced by approximately 90% following BTAH treatment during 161 days from the previous year. The leakage of one of the two sprinkler copper tubes was investigated with optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction analysis to determine the formation of Cu-BTA film inside the corrosion pits. All the inner components of the corrosion pits were coated with Cu-BTA films suggesting that BTAH molecules penetrated the corrosion products. The Cu-BTA film was about 2 nm in thickness at the bottom of a corrosion pit. A layer of CuCl and $Cu_2O$ phases lies under the Cu-BTA film. This complex structure effectively prevented the propagation of corrosion pits in the sprinkler copper tubes and reduced the water leakage.

• 소성∙가공
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• 제30권1호
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• pp.35-42
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• 2021

Magnesium alloys are used in electronic devices such as laptops due to their lightweight features as well as vibration absorption and electromagnetic shielding properties. However, the precision of electronics is limited by the large number of small and precise ribs, the cost-effective manufacture of which requires appropriate technology. Plate forging is an efficient manufacturing process that can address these challenges. In this study, plate forging of magnesium alloys was investigated specifically for the fabrication of laptop cover. The plate forging process with back-pressure was used for near-net shape formation. Finite element analysis was used to select appropriate variables for back-pressure formation to generate ribs of various sizes and shapes without defects. The reliability of the analysis was verified to manufacture the prototype. The effect of back-pressure can be verified via fabrication of prototypes as well as structure and forming analysis based on finite element method. The process design factor of back-pressure increases formability without defects of under-filling and flow-through. Moreover, the tensile strength was maintained even after high temperature plate forging at 370 ℃, and the elongation was improved.

• 방사성폐기물학회지
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• 제20권3호
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• pp.269-278
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• 2022

The buffer is a critical barrier component in an engineered barrier system, and its purpose is to prevent potential radionuclides from leaking out from a damaged canister by filling the void in the repository. No experimental parameters exist that can describe the buffer expansion phenomenon when Kyeongju bentonite, which is a buffer candidate material available in Korea, is exposed to groundwater. As conventional experiments to determine these parameters are time consuming and complicated, simple swelling pressure tests, numerical modeling, and machine learning are used in this study to obtain the parameters required to establish a numerical model that can simulate swelling. Swelling tests conducted using Kyeongju bentonite are emulated using the COMSOL Multiphysics numerical analysis tool. Relationships between the swelling phenomenon and mechanical parameters are determined via an artificial neural network. Subsequently, by inputting the swelling tests results into the network, the values for the mechanical parameters of Kyeongju bentonite are obtained. Sensitivity analysis is performed to identify the influential parameters. Results of the numerical analysis based on the identified mechanical parameters are consistent with the experimental values.

• 동아시아경상학회지
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• 제11권4호
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• pp.11-18
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• 2023

Purpose - By filling the existing research hole and supplying a whole evaluation, this test wants to offer actionable insights for stakeholders navigating the intersection of sustainability and financial prosperity. Ultimately, this study contributes to the evolving speak on ESG, fostering a deeper comprehension of its implications for fostering sustainable economic increase. Research design, data, and methodology - Based on the numerous prior literature, the current study adopts a rigorous and systematic approach to discover the connection between Environmental, Social, and Governance (ESG) performance and its effect on a financial boom. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method is the guiding framework for systematically accumulating and analyzing earlier research studies. Result: The finding of this study indicates that using ESG-pushed innovation, practitioners can force technological advancements inside their respective industries. By combining sustainability with research and improvement tasks, corporations can be leaders in selling economic boom through current, green solutions. Conclusion - In summary, this study concludes that embracing those findings in this study allows practitioners and managers to enhance their organization's easy regular, well-known traditional regular standard overall performance and undoubtedly contribute to a broader financial boom via leveraging the transformative strength of ESG necessities.

• 자원환경지질
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• 제51권6호
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• pp.521-529
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• 2018

본 연구는 인천국제공항 3, 4단계 건설 사업부지 토취원인 을왕산 지역의 암석 내에 존재하는 불소의 자연적 기원을 규명하고자 암석학적, 광물학적 분석을 실시하였다. 용유도 을왕산은 트라이아스기 흑운모화강암이 분포하는 지역으로, 흑운모화강암과 압쇄암의 불소의 농도는 각각 1,700과 2,400 mg/kg 정도로 매우 높게 나타난다. 흑운모화강암에는 형석으로 인해 불소함량이 높게 나타나는데, 현미경 관찰 결과, 형석은 알칼리장석이나 사정석의 벽개와 균열을 따라 채워진 세맥 형태로 나타나거나, 석영과 함께 들어온 광맥 형태로 존재하는 것으로 보아 열수에 의하여 이차적으로 형성된 것으로 해석된다. 압쇄암은 견운모에 의해 불소함량이 높게 나타난다. 현미경하에서 관찰 결과 견운모는 주변에 있는 석영과의 경계가 뚜렷하지 않고 견운모가 석영의 균열에 채워져 있으며, 압쇄된 작은 결정의 석영을 포획하고 있는 특징을 보이며, 이는 견운모 또한 열수에 의한 이차적인 변질작용으로 형성된 것임을 지시한다. 따라서 용유도 을왕산 화성암류 내 존재하는 불소는 열수에 의해 이차적으로 생성된 자연발생적 기원인 것으로 판단된다.

• 혜화의학회지
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• 제28권2호
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• pp.41-47
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• 2019

Objectives : Atopic dermatitis is an irritable skin disease accompanying rash and itching leading to impaired skin barrier. ATO-ALL is an ethanol extract of natural products comprising 12 herbs and effective on atopic dermatitis. In this study, we aimed to propose that the effect of ATO-ALL on skin regeneration in human keratinocyte cell line, HaCaT cells. Methods : To evaluate the skin regenerating effects of ATO-ALL, scratch wound healing assay, bromodeoxyuridine (BrdU) assay, and propidum iodide (PI) assay were performed using cultured HaCaT cell line. Result : Scratch wound healing assay showed that ATO-ALL was able to enhance the gap filling activity more than 2-fold at 7 ppm concentration compared with control group. BrdU assay demonstrated that ATO-ALL treatment increased the de novo cell proliferation in a dose-dependent manner. Finally, PI assay indicated that the cell cycle of HaCaT cells was modulated by ATO-ALL treatment. Conclusions : These results suggested that ATO-ALL may have skin regenerating effects by increasing cell proliferation via cell cycle regulation. Taken together, ATO-ALL is supposed to have a potential on regeneration of damaged skin or functional disease including atopic dermatitis.

• 디자인학연구
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• 제17권2호
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• pp.479-486
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• 2004

20세기에는 물질과 분석적 디자인의 중시로 환경문제가 크게 대두되었다. 이제 21세기를 맞아 의미와 전체와의 조화의 개념이 중시되는 전일적 디자인방법이 필요하다. 따라서 본 연구의 목적은 동양의 전일적 사고에 바탕한 21세기의 새로운 디자인패러다임과 디자인방법을 제시하는데 있다. 구체적인 연구의 내용으로는 '유ㆍ불ㆍ도교 등의 동양사상에서 나타나는 전일적 개념이 파악되고(4장)', '통일성, 조화성, 변화성을 중심으로 한 전일적사고의 주요가치들이 분석되었으며(5장)', 이를 바탕으로 새로운 디자인방법의 대안으로서 '첫째-대상관찰, 둘째-대상평가, 셋째-대상개선의 3단계로 구성된 전일적인 디자인프로세스가 제시되었다(6장)' 그리고 결론으로서 각 단계의 중심적 디자인가치가 아래와 같이 규명되었다. 대상관찰 단계-대상을 바라봄에 있어 분리보다는 '전일적 관점'을 중시한다. 대상평가-가치를 판단함에 있어 차별과 대립보다는 '화합과 조화를 중시' 한다. 대상개선-창조의 개념은 변증법적 발전(creation)보다는 '순환과 변용과정의 개선적 변화(process of transformation)'를 중시한다.

• 무역상무연구
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• 제16권
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• pp.331-359
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• 2001

Uniform Electronic Transactions Act (1999) Drafted by the National Conference of Commissioners on Uniform State Laws. The Act allows the use of electronic records and electronic signatures in any transaction, except transactions subject to the Uniform Commercial Code. The fundamental purpose of this act is to remove perceived barriers to electronic commerce. The Act's a procedural statute. It does not mandate either electronic signatures or records, but provides a means to effectuate transactions when they are used. The primary objective is to establish the legal equivalence of electronic records and signatures with paper writings and manually-signed signatures. With regard to the general scope of the Act, the Act's coverage is inherently limited by the definition of "transaction." The Act does not apply to all writings and signatures, but only to electronic records and signatures relating to a transaction, defined as those interactions between people relating to business, commercial and governmental affairs. The exclusion of specific Articles of the Uniform Commercial Code reflects the recognition that, particularly in the case of Articles 5, 8 and revised Article 9, electronic transactions were addressed in the specific contexts of those revision processes. In the context of Articles 2 and 2A the UETA provides the vehicle for assuring that such transactions may be accomplished and effected via an electronic medium. At such time as Articles 2 and 2A are revised the extent of coverage in those Articles(Acts) may make application of this Act as a gap-filling law desirable. Similar considerations apply to the recently promulgated Uniform Computer Information Transactions Act (UCITA). Another fundamental premise of the Act is that it be minimalist and procedural. The general efficacy of existing law, in an electronic context, so long as biases and barriers to the medium are removed, confirms this approach. The Act defers to existing substantive law. Specific areas of deference to other law in this Act include: i) the meaning and effect of "sign" under existing law, ii) the method and manner of displaying, transmitting and formatting information in section 8, iii) rules of attribution in section 9, and iv) the law of mistake in section 10.