• E2M - 전기 전자와 첨단 소재
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• 제8권6호
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• pp.708-714
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• 1995

We have discussed the buried-channel(BC) behavior through the subthreshold characteristics of submicron PMOSFET device fabricated with twin well CMOS process. In this paper, we have guessed the initial conditions of ion implantation using process simulation, obtained the subthreshold characteristics as a function of process parameter variation such as threshold adjusting ion implant dose($D_c$), channel length(L), gate oxide thickness($T_ox$) and junction depth of source/drain($X_j$) using device simulation. The buried channel behavior with these process prarameter variation were showed apparent difference. Also, the fabricated pMOSFET device having different channel length represented good S.S value and low leakage current with increasing drain voltage.

• Journal of Microbiology and Biotechnology
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• 제15권1호
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• pp.206-215
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• 2005

Polyhydroxyalkanoates (PHAs) are homo or hetero polyesters of (R)-hydroxyalkanoates accumulated in various microorganisms under growth-limiting condition in the presence of excess carbon source. They have been suggested as biodegradable substitutes for chemically synthesized polymers. Recombinant Escherichia coli is one of the promising host strains for the economical production of PHAs, and has been extensively investigated for the process development. The heterologous PHA biosynthetic pathways have been established through the metabolic engineering and inherent metabolic pathways of E. coli have been redirected to supply PHA precursors. Fermentation strategies for cultivating these recombinant E. coli strains have also been developed for the efficient production of PHAs. Nowadays, short-chain-length (SCL) PHAs are being re-invited due to its improved mechanical properties and possible applications in the biomedical area. In this article, recent advances in the development of metabolically engineered E. coli strains for the enhanced production of SCL-PHAs are reviewed. Also, medical applications of SCL-PHAs are discussed.

• 한국결정성장학회지
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• 제8권3호
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• pp.474-477
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• 1998

고체표면에 흡착된 기체분자의 표면확산과정을 Markoff 확률과정 방법을 이용하여 논의한다. 흡착분자의 표면확산거리와 표면피복률간의 관계식을 유도한다.

• 한국인쇄학회지
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• 제12권1호
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• pp.81.1-91
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• 1994

Irradiation of aromatic diazonium salts resulted in an effcient elimination of nitrogen, yielding substitution products. This paper was not only studies about photolysis of aromatic diazonium with double salts but also coexistence of ion and radical when they was photolysis. Photolysis of aromatic diazonium was depend on excite wave length therefore photolysis products out put different absorption intensity such other. We also confirmed coexistence of ion and radical when they was accomplished photolysis. In case of BD, there are ion decomposition process about 90 percentage, decreased ion decomposition process the other side radical`s it was becomeing increased according to excite of short-wave length.

• 대한수학회논문집
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• 제14권3호
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• pp.611-625
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• 1999

We consider ΜΑΡ/G/ 1 finite capacity queue with mul-tiple thresholds on buffer. The arrival of customers follows a Markov-ian arrival process(MAP). The service time of a customer depends on the queue length at service initiation of the customer. By using the embeded Markov chain method and the supplementary variable method, we obtain the queue length distribution ar departure epochs and at arbitrary epochs. This gives the loss probability and the mean waiting time by Little's law. We also give a simple numerical examples to apply the overload control in packetized networks.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2004년도 춘계학술대회
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• pp.7-14
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• 2004

In this paper, we present an effective method for process control using the Demerit-EWMA control chart in the process where nonconforming units or nonconformities are occurred by various types. We compare performance of Demerit control chart, Demerit-CUSUM control chart and Demerit-EWMA control chart based on the average run length.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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• pp.309-313
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• 2000

In order to meet the industrial requirement, precision grinding with brush tool has been applied. To analyze the brush tool characteristics, several parameters including numbers of brush string installed in a single holder, depth of cut and brush length have been changed. Several data from various source were acquired using AE, acceleration and tool dynamometer during the process. Consistent results revealing certain trend with respect to each process condition were observed.

• Journal of the Korean Data and Information Science Society
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• 제15권2호
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• pp.431-439
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• 2004

In this paper, we present an effective method for process control using the Demerit-EWMA control chart in the process where nonconforming units or nonconformities are occurred by various types. We compare performance of Demerit control chart, Demerit-CUSUM control chart and Demerit-EWMA control chart based on the average run length(ARL).

• 한국광학회지
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• 제14권4호
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• pp.359-364
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• 2003

편광에 따른 성능 변화가 작은 deep-ridge 도파관 구조에 제작이 용이한 double-sided 프로세스를 이용하여 구현할 수 있는 편광에 무관한 매우 짧은 결합 길이를 가지는 double-sided deep-ridge 도파관 구조를 가지는 새로운 수직 방향성 결합기를 제안하고 여러 가지 구조 파라미터들이 결합길이에 미치는 영향에 대하여 연구하였다. 도파관 폭의 변화에 대한 결합길이의 변화는 코어 두께의 변화에 대한 결합길이의 변화보다 작게 나타나는 것을 볼 수 있었다. 내부 클래딩 영역의 두께가 감소할수록, 코어 두께가 감소할수록 결합 길이가 감소함을 볼 수 있었다. 또한 같은 코어 두께에 대해서는 내부 클래딩 영역의 두께가 감소할수록, 같은 내부 클래딩 영역의 두께에 대해서는 코어 두께가 감소할수록 편광에 관계없이 결합 길이가 같아지는 도파관 폭이 작아짐을 볼 수 있었다.

• 한국정밀공학회지
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• 제22권3호
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• pp.86-92
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• 2005

In this paper a forward-backward can extrusion process are analyzed by using rigid-plastic FEM simulation. FEM simulation is conducted to investigate forming characteristics such as deformation modes fur different process parameters. Design parameters such as thickness ratio, punch angle, friction factor and diameter ratio are selected to study the effect of them on the pattern of material flow. The analysis is focused mainly on the influences of the design factors on deformation pattern in terms of forming load, extruded length ratio and volume ratio. It is known for the simulation that the forming load, the length ratio and the volume ratio increase as the thickness ratio (TR), the wall thickness in forward direction to that in backward direction, decreases. The various punch angles have slight influence on the forming load. length ratio and volume ratio. However friction factor have little effect on the forming characteristics such as the forming load, volume ratio and so on. In addition the forming load increases as diameter ratio (DR), the outer diameter of a can in forward direction to that in backward direction, increases. Furthermore the extruded length ratio is lowest with a certain value of DR=0.85 among diameter ratios. Pressure distribution exerted on the die-material interface is illustrated schematically.