• Journal of the Korean Institute of Telematics and Electronics
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• v.23 no.1
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• pp.42-45
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• 1986

This paper introduces novel functionally integrated logic elements which are conceptuallized for large scale integrated circuits. Efforts are made to minimize the gate size as well as to reduce the operational voltage, without sacrificing the speed performance of the gates. The process used was a rather conventional collector diffusion isolation(CDI) process. New gate structures are formed by merging several transistors of a gate in the silicon substrate. Thested elements are CML(Current Mode Logic) and EECL (Emitter-to-Emitter Coupled Logic)gates. The obtained experimental results are power-delay product of 6~11pJ and delay time/gate of 1.6~1.8 ns, confirming the possibility of these novel gate structures as a VLSI-candidate.

• World Technopolis Review
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• v.1 no.3
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• pp.186-191
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• 2012

To understand South Korea's economic success several contending paradigms have emerged, ranging from a neo-classical explanation to a statist perspective, and Schumpeterian structuralism. The Korean miracle can be seen as a product of multiple factors involving the strategic choice of export-led growth, timely and active human-capital investment, business activism, and individual innovative ideas. However, South Korea needs more complex and innovative ideas to continue its both economic growth and S&T Development. The ideas of Schumpeterian structuralist needs to be more emphasized. Changing state-society relations and subsequent policy choice are greatly influenced by the industrial life cycle. The industrial life cycle is closely related to the historical sequencing and diffusion of technology. The complex mixture of statist-market-Schumpeterian structuralist perspectives could lead more technologically advanced society in South Korea.

• Corrosion Science and Technology
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• v.7 no.2
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• pp.130-133
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• 2008

Corrosion of silver by outgassed sulfur species from rubber has been investigated by means of quartz crystal microbalance technique (QCM) and cathodic reduction technique. Silver specimens were placed together with a rubber of predefined quantity in an enclosed environment. Corrosion progressed linearly with time and silver sulfide was found as the corrosion product during all the tests. No significant dependence on RH was observed, while the corrosion rate increased as temperature rose. Furthermore the corrosion rate increased logarithmically with the quantity of the rubber placed in the exposure environment. It may be suggested that the corrosion rate of silver is determined by the amount of outgassed sulfur species which is a function of temperature and the quantity of rubber contained in the exposure environment.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.2
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• pp.134-143
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• 1997

A theoretical and experimental study has been performed to investigate the characteristics of ice-slurry product. By diffusion-controlled model, the possibility of ice slurry has been theoretically anticipated. The water vapor evaporated from the surface of droplets is extracted continuously from the chamber by a vacuum pump. The droplet diameter was measured by silion immersed method. The ice slurry has been obtained by spraying droplets of ethylene-glycol aqueous solution in the chamber where pressure is maintained under the triple point of water. The droplet of which the diameter is $300{\mu}m$, and the initial temperature is $20^{\circ}C$, was changed into ice particle within the chamber of which the height is 1.33m.

• Journal of the Korean Ceramic Society
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• v.55 no.3
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• pp.299-306
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• 2018

In order to improve the hardness of commercial bone china, we suggested a chemical strengthening process and new glaze for its process. New glaze contained about two times more $Na_2O$ and $Al_2O_3$ and had a higher transition temperature than that of commercial frit. Chemical strengthening enhanced the hardness of the new glaze-coated bone china by over 30% compared to that of commercial product. The change of glaze composition influenced potassium ion diffusion distance and depth of strengthened layer during chemical treatment. After chemical strengthening of new glaze-coated bone china, the residual compressive stress inside the glaze was measured and found to be greater than 160 MPa.

• Journal of the Korean Ceramic Society
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• v.25 no.4
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• pp.415-423
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• 1988

Mixtures of carbon and silica (about 0.46${\mu}{\textrm}{m}$) which was synthesized by the hydrolysis of ethyl silicate, the molar ratio of silica/carbon was fixed as 1/10(weight ratio : 1/2), were nitrided in the temperature range 135$0^{\circ}C$~150$0^{\circ}C$. The phse of the product Si3N4 was $\alpha$ phase and the morphology was hexagnoal prism and the nitridation reaction was completed in 5 hrs at 150$0^{\circ}C$ or 7hrs at 145$0^{\circ}C$. The reaction rate above 150$0^{\circ}C$ was diffusion-controlled, following Jander equation. Activation energy Q was derived from the Arrhenius plot and the value was about 101kcal/mol. Axis ratio of Lattice constants(c/a) was 0.726 and unit volume was $\AA$3, the larger the molar ratio of carbon/Alkoxide was, the smaller the particle size of $\alpha$Si3N4 was.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 1998.04a
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• pp.144-153
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• 1998

Sorbents of calcined limestone and oyster particles having a diameter of about 0.63mm were exposed to simulate fuel gases containing 5000ppmv H2S for temperatures ranging from 600 to 800C in a TGA. The reaction between CaO and H2S proceds via an unreacted shrinking core mechanism. The sulfidation rate is likely to be controlled primarily by countercurrent diffusion through the product layer of calcium sulfide(CaS) formed. The kinetics of the sorption of H2S by CaO is sensitive to the reaction temperature and particle size, and the reaction rate of oyster was faster than the calcined limestone.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2005.05a
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• pp.1089-1094
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• 2005

Peterson and Mahajan(1978)은 Bass모형을 확장한 종속적 신상품 수요확산모형(contingent diffusion model)을 처음으로 제안하였다. Peterson and Mahajan(1978)이 명명한 상품간의 종속적(contingent) 관계란, 주 상품의 경우는 다른 상품에 독립적이지만 종속적 상품(contingent product)의 경우는 잠재시장이 주 상품의 누적 구매자 수에 의존하는 경우를 말한다. 그런데 Peterson and Mahajan이 제안한 기존 모형은 실질적 활용에 있어서 모형 추정이 불가능하다는 단점을 지니고 있을 뿐만 아니라, Bass(1969) 모형처럼 엄밀한 확률이론에 근간을 둔 모형이라기보다는 직관과 통찰력에 근간을 둔 Bass모형의 단순한 확장 모형이라는 한계를 지니고 있다. 본 연구는 이러한 한계를 극복하고 확률이론을 바탕으로 종속적 관계를 가지는 상품들에 대한 수요 확산모형을 개발하는데 목적이 있다. Bass의 신상품확산모형은 hazard 함수 모형의 일종으로 신상품의 확산을 혁신과 구전효과로 설명한 과학적 모형이다. 본 연구에서는 확률이론을 활용함으로써 이러한 Bass의 hazard 함수 모형의 확장이 가능함을 보이고, 이를 토대로 종속적 관계에 있는 신상품들에 대한 수요 확산모형을 개발하였다. 또한 개발된 모형을 한국의 이동전화와 무선인터넷 사례에 적용하여 실증 분석을 수행하였다.

• Korean Management Science Review
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• v.28 no.1
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• pp.25-42
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• 2011

The mobile industry is the key foundation of digital convergence, and its constant growth is expected. Among mobile industries, new products leading the development of devices are the Emerging Device. This study is conducted to find out factors making differentiated by comparing the structural equation model(SEM) of the Tablet PC and the e-Book Reader. The main findings are as follows. First, the application of TAM to the Emerging Device shows that fitness of the model is generally high but the effect of Perceived Ease of Use has not been verified or found insignificant. Second, the acceptance model of the Tablet PC and the e-Book Reader has found that playfulness stimulates acceptance intentions. Third, the cost level of the Emerging Device acceptance model is not a factor stimulating consumers' acceptance intentions. Fourth, product attributes of the Tablet PC and the e-Book Reader to differentiate themselves from the other device are Functionality and Playfulness respectively.

• 한국신재생에너지학회:학술대회논문집
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• 2009.06a
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• pp.374-377
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• 2009

The operating temperature of Proton Exchange Membrane Fuel Cell (PEMFC) usually has to be limited under $100^{\circ}C$ to maintain the proper ionic conductivity. Therefore, the only product from reaction, water, is in the liquid phase. Two-phase flow makes the flow phenomenon in the channel difficult to understand and predict. Water blocking in the PEMFC channel or the pore of Gas Diffusion Layer (GDL), called flooding, is known as the main effect of PEMFC degradation. To analyze two-phase flow, the PEMFC with transparent acrylic plate was used. Two-phase flow patterns were observed by varying the current density. When the PEMFC is mounted horizontally, water in the cathode is mainly transported on the interface between the channel and GDL.