• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1721-1725
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• 2010

This paper reports the fabrication of geometry-controlled carbon microneedles by a backside exposure method and pyrolysis. The SU-8 microneedles are a polymer precursor in a carbonization process, which geometries such as base diameter, spacing, and aspect ratio can be controlled in a photolithography step. Using this fabrication method, highly reproducible carbon microneedles, which have high aspect ratios of more than 10 and very sharp nanotips, can be realized. The quartz surface with carbon microneedles becomes very hydrophilic and its wettability is adjusted by carrying out the silane treatment. In the carbon microneedle array ($3\;{\mu}m{\times}3\;{\mu}m$), the contact angle is extremly enhanced (${\sim}180^{\circ}$); this will be advantageous in developing low-drag microfluidics and labs-on-a-chip as well as in other bio-applications.

• Elastomers and Composites
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• v.37 no.4
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• pp.224-233
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• 2002

This study has investigated the flame retardant properties of EPDM rubber with the addition of various flame retardants. Carbon black, stearic acid, zinc oxide cross-linking agent were mixed with EPDM rubber to produce the base rubber E0 without the addition of flame retardants. Phosphorus flame retardant Tricrecyl phosphate(TCP) was added to E0 in 0.5, 1, 1.5, 2 phr to make E1~E4 samples and red phosphorus was added in 3, 6, 9, 12 phr to make E5~E8 samples. A flame retardant of the bromine family Decabromodiphenyloxide(DBDPO), and a chlorinated paraffin retardant of the chlorine family was added to E0 in 3, 6, 9, 12 phr to make E9~E12 and E13~E16 samples, repectively. Basic physical properties such as tensile strength, tear strength and hardness were measured for all the rubber samples with various flame retardant additions. There was no substantial differences. On the other hand, Oxygen index and UL94 were measured to study flame retardant properties. From oxygen index measurements E0 sample showed a value of 23.5%, indicating the improvement of flame retardant properties. Also from UL94 measurements, it was found that addition of red phosphorus resulted in maximum flame retardant effect. It was found that increasing the amount of addition resulted in decreasing combustion rate and improving flame retardant effect regardless of the kind of flame retardant.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.177-184
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• 2017

Understanding trends and drivers of technology diffusion is imperative to forecast new technology adoption and understand the process of technological innovation. Our research utilizes a quantitative trend analysis considering both technological and economic indicators for trends and drivers of technology diffusion for 32nm, 22nm, and 14nm logic semiconductor technology. In terms of technological performance, the technology diffusion curve showed an S-curve pattern during the stages of maturity and decline, and the diffusion curve showed evidence supporting the learning curve. The diffusion curve showed the life cycle duration of 2 years, and the rate of technological performance and obsolescence are observed quantitatively between generations. Architectural innovation is affected by technological drivers more significantly than economic drivers. This research has implications as empirical research on the trends and drivers of technology diffusion in the high-tech semiconductor industry, and is meaningful in forecasting new technology adoption or build technology strategy.

• Proceedings of the Korea Technology Innovation Society Conference
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• 2017.05a
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• pp.161-174
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• 2017

최근 들어 기술벤처기업에 대한 투자가 증가하고, 이를 위한 기술신용평가의 역할이 증대하였다. 그러나 금융권에서 바라보는 기술신용평가의 경우, 해당 기업의 신용등급이나 기술(력) 등급평가에 초점을 두어, 대상기술의 사업화 및 수익성 관점을 체계적으로 반영하지 못하는 한계를 지닌다. 따라서, 벤처캐피털(VC)이나 엔젤투자자를 비롯한 금융권에서 대상기술의 수익성 정보를 참조하거나 기술벤처기업 설립시 기술지분을 참고하는 등, 기존 기술이전거래 협상참조용이나 담보 보증용에 널리 이용되던 기술가치평가의 활용범위가 급격히 확대되고 있다. 제조 서비스 분야의 일반 기술 뿐만이 아니라, 바이오 제약 의료 분야 기술에서도 미래 투입되어야 하는 사업화 소요기간 및 비용을 고려하여 기술가치를 산정해야 할 때가 있다. 기존의 현금흐름할인법(DCF법)이 연속된 투자에 대한 고려를 못하거나 기술적용 제품의 상용화 투입비용에 대한 확률적인 속성을 반영하지 못하는 등 한계점을 지니고 있다. 그러나 기술과 투자의 가치는 기회가치로 보고 자원배분을 위한 의사결정 정보를 감안해야 하므로, 실물옵션의 개념을 적용하는 것이 바람직하다고 여겨진다. 흔히 기업가치를 평가할 때 주가의 변동성(volatility) 개념을 도입하여 전일종가 대비 익일시가의 분산값을 활용하기도 한다. 이러한 개념을 기술가치평가에 적용하기 위해서는 '주가의 연속성(상대적 미세한 변화)' 및 '양(+)의 조건'을 고려해야 하는데, 실제 기술가치평가 상의 현금흐름은 사업초기년도 음(-)의 값이 나타나거나 2~3년 내외의 짧은 수익예상기간 하에서는 주가와 같은 변동성을 도출하는데 무리가 있다. 따라서 많은 문헌에서 연구된 바와 같이, 실물옵션 기반의 기술가치 산정을 위한 블랙-숄즈 모형에서 변동성과 기초자산가치, 그리고 사업화비용 간의 관계를 살펴볼 필요가 있다. 아울러 옵션가격결정모형(Option Pricing Model)에서 불확실성을 반영한 기초자산의 현재가치와 사업화비용의 현재가치분이 특정 임계조건 하에서 '옵션행사 포기(NAT; no action taken)' 영역으로 구분되는 지를 수학적으로 도출하고 관찰변수(입력값)에 따른 옵션가치 산출표를 개발하여 제시한다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2002.05a
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• pp.1-13
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• 2002

최근 자동차가 편리성과 안전성을 추구함에 따라서 자동차 부품도 과거의 기계식 동작 방법에서 전자 제어 장치가 부착된 전자식 동작 방법으로 발전되어 가고 있는 추세입니다. 또한 연비 향상을 위하여 부품의 소형화가 급속히 추진되고 있습니다. 이러한 전자화, 소형화를 실현시키기 위해 자동차 부품에서의 정밀성이 요구되어 지고 있고, 부품 제조 측면에서는 고속화, 정확성이 요구되고 있는 실정입니다. 당사의 경우 CBS (Conventional Brake System)를 생산하다가 전자 제어 장치가 부착된 ABS (Anti-lock Brake System)의 생산을 시작할 때, 부품의 정밀도를 좌우하는 각 치수의 공차 영역이 전체적으로 CBS 대비 약 1/5 수준밖에 되지 않고, 가공 속도는 약 2 배가 빨라야 하기 때문에 생산 준비 단계에서 많은 시행 착오를 겪어야만 했습니다. 여기서 당사가 ABS를 양산하면서 겪은 경험을 토대로 기술토록 하겠습니다. 가공 기술의 경우 고속, 정밀 가공을 실현시키기 위해서 크게 4 가지 측면을 고려해야만 하며, 그 4가지는 설비, Tool Holder, Tool, Chip 측면입니다. 먼저 설비가 고정도가 되기 위해 고강성을 필요로 하는 것은 물론 가동중에 필연적으로 발생하는 열변형에 대한 대책을 수립하지 않으면 안됩니다. 이러한 열변형은 설비 설계 단계에서 대책을 수립할 수 있는 것도 있지만 주위 온도 변화에 의한 열변형처럼 사용 중에 발생되는 것은 설비 사용자가 장시간에 걸친 Data 를 확보하여 대책을 수립하지 않으면 안됩니다. 또한 Tool Holder의 정도도 일반적으로 사용하는 것보다는 고정도의 것이 요구되어지므로 Tool Holder Maker 에 반드시 요구 정도를 명기하여 주문하여야 합니다. Tool도 고속화를 실현시키기 위해 고정도의 다이아몬드 공구가 필요하였고 이를 국내에서 개발하기 위해 많은 시행 착오를 겪어야만 했습니다. 또한 Chip 배출이 고정도의 필수 고려 항목으로서 당사에서는 경우에 따라 여러 가지의 방법을 사용하고 있습니다. 조립 기술의 경우 스테인레스 박판을 열변형을 최소로 하면서 용접을 하기 위해서 레이저 용접을 도입하였고, 부품을 압입하면서 정확하고 정밀한 치수 셋팅을 위하여 서버 모타를 이용한 압입 방법을 사용하였습니다.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.177-182
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• 2019

As progress of technology, Artificial Intelligence is applied in various fields of industry such as finance, production, medical treatment, service, art by changing the way they look continuously. As AI is progressive area, We have to know what kind of changing is merged in human society by AI. In this paper, through the investigations of Artificial Intelligence's concept and the way Artificial Intelligence's technology is implemented in modern industry, we studied positive effect and negative effect of AI. By this study, In conclusion, by realizing how close Artificial Intelligence had come to our life, we can prepare to seek a foothold to deal with this Artificial Intelligence.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.163-172
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• 2022

Purpose: To secure efficient thermal management technology for Li-ion batteries, the applicability of the system applied with single-phase immersion technology was checked through an experiment. Method: Using JH3 pouch cells produced by LG-Chem, Korea, A 14S2P module was manufactured and immersed in a vegetable-based cooling fluid produced by Cargill, USA, and then charged and discharged at a rate of 0.3C to 1C to check the heat distribution. Result: It was possible to manage and there was no change in the molecular structure of the immersion solution. Conclusion: It was confirmed that the immersion cooling method can be applied to the thermal management of Li-ion batteries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5468-5475
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• 2015

This present work was aimed to analyse characteristics of fermentation and aging of Korean traditional cheongju prepared by adding of different brewing water. The three different mashes were used for fermentation and maturation. The cheongju(A) was prepared without adding of brewing water in two stage mashing. Cheongju(B) and cheongju(C) were made with adding of 1 liter and 2 liter brewing water in two stage mashing respectively whereas the cheongju(B) and cheongju(C) showed higher fermentation ability than that of cheongju(A) regarding to pH, ethanol, specific gravity and sugar concentration(brix). In terms of volatile compounds content after six months aging, cheongju(A and B) prepared by adding brewing water showed the higher content of ethyl acetate than that of cheong(C) and the concentrations were maintained during the aging period. In addition, the content of fusel oil(n-propanol, i-butanol, n-butanol, i-bmyl alcohol, n-bmyl alcohol)indicated similar pattern as ethyl acetate. The organic acid of cheongju B(4873.46 mg/l) and C(4963.12 mg/l) also indicated the higher content than that of cheongju A(4661.47 mg/l). In conclusion, cheongju B and C prepared by adding brewing water in two stage mashing showed better quality and taste than that of cheongju A.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.36-42
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• 2021

With recent developments in the Fourth Industrial Revolution, the manufacturing industry has changed rapidly. Through key aspects of Fourth Industrial Revolution super-connections and super-intelligence, machine learning will be able to make fault predictions during the foam-making process. Polyol and isocyanate are components in polyurethane foam. There has been a lot of research that could affect the characteristics of the products, depending on the specific mixture ratio and temperature. Based on these characteristics, this study collects data from each factor during the foam-making process and applies them to machine learning in order to predict faults. The algorithms used in machine learning are the decision tree, kNN, and an ensemble algorithm, and these algorithms learn from 5,147 cases. Based on 1,000 pieces of data for validation, the learning results show up to 98.5% accuracy using the ensemble algorithm. Therefore, the results confirm the faults of currently produced parts by collecting real-time data from each factor during the foam-making process. Furthermore, control of each of the factors may improve the fault rate.

• The Journal of the Convergence on Culture Technology
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• v.9 no.2
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• pp.553-560
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• 2023

The study is about domestic industries following the migration of hubs (innovation, manufacturing) to other countries and the hub-oriented US industries (batteries, semiconductors, electric vehicles). Additionally, the ongoing trade tensions between the United States and China may have also played a role in companies moving their operations to the United States. The result of such a move could potentially include job creation in the United States, as well as increased investment in the U.S. manufacturing sector. However, it is also possible that there could be negative consequences, such as higher prices for consumers or disruptions to supply chains during the relocation process. However, such IRA, Chips Act scenario would likely also have negative consequences (Inflation in the home country) for the countries whose industries moved to the US, as they would lose jobs, investment, and possibly face economic difficulties as a result. As the result of the empirical analysis of the export scale of Korea and the United States, changes in the movement of global supply hubs are related to factors such as geopolitical price increases and consumption declines. In order to respond to these changes, this paper emphasizes the need to prevent the result of de-advantage by moving the production area of the scale.