• 한국자기학회:학술대회 개요집
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• 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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• pp.33-59
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• 2000

Demonstrated uniform MR and resistance across 6 inch wafer, Demonstrated successful integration of MTJ and CMOS, Measured address access time of 8ns and read cycle time of 18ns for 256${\times}$2 arrays at 3.0V using a single transistor and MTJ for a cell

• 한국토양비료학회지
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• 제41권4호
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• pp.273-278
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• 2008

이 연구는 Tempe 압력셀에서 1-단계 유출법을 이용하여 불포화수리전도도 추정모형인 van Genchten 모형과 Campbell 모형을 비교하고자 수행하였다. 토양 코아(컬럼)는 서울대학교 농업생명과학대학 부속 사과 과수원에 위치한 송정통 (the fine loamy, mesic family of Typic Hapludults) 의 Ap1, B1, C 층에서 채취하였다. 각 층위의 컬럼들에 대해 포화수리전도도를 측정하고 Tempe 압력셀에서 수분보유곡선을 측정한 후 최소좌승법으로 모형의 변수를 도출하였다. 수분보유곡선에서 모형과 측정치는 잘 적합하였고 포화근처에서 Campbell 모형의 적합도가 van Genchten 모형보다 약간 더 좋았다. Campbell 모형의 불포화수리전도도가 van Genchten 모형보다 높게 추정되었으며 1-단계 유출법의 불포화수리전도도는 C층에서 van Genchten 모형과 잘 적합하였고 Ap1층, B1층에서는 두 모형의 중간에서 van Genchten에 약간 더 가까웠다. 따라서 불포화수리전도도 측정범위-10~-75kPa에서 van Genuchten 모형이 실측치와 더 적합하다 할 수 있었고, 포화근처에서는 수분보유곡선과의 적합도가 Campbell 모형이 더 높은 것으로 보아 상대적으로 수리전도도함수의 정확도가 높을 것으로 추측할 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.431-441
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• 1991

A robust H$_{\infty}$ control design methodology and its application to a Space Station attitude and momentum control problem are presented. This new approach incorporates nonlinear multi-parameter variations in the state-space formulation of H$_{\infty}$ control theory. An application of this robust H$_{\infty}$ control synthesis technique to the Space Station control problem yields a remarkable result in stability robustness with respect to the moments-of-inertia variation of about 73% in one of the structured uncertainty directions. The performance and stability of this new robust H$_{\infty}$ controller for the Space Station are compared to those of other controllers designed using a standard linear-quadratic-regulator synthesis technique.que.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.649-656
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• 2002

Fibrinolytic microorganisms were screened from 42 samples of Korean fermented food (7 kinds of Chungook-jang, 14 kinds of commercial Doen-Jang, 5 kinds of home-made Doen-jang, and 16 kinds of Jeot-gal), 15 samples of Japanese fermented food (5 kinds of home-made soybean paste, and 10 kinds of Natto), and 19 samples of Indonesian fermented food (Tempe) as well as starters of Meju (500 microflora from Korea, and 22 from China). Initially, 11 isolates with strong fibrinolytic activity were selected for further characterization. The fibrinolytic activity of the 11 isolates ranged from 89 to 199% of standard plasmin. Four strains, M5l from Korean fermented food (Meju), I 1-1, I 1-4, and I 5-1 from Indonesian fermented food (Tempe), were chosen based on the degree of activity and reproducibility, and identified as Staphylococcus sciuri, Citrobacter or Enterobacter, Enterococcus faecalis, and Bacillus subtilis, respectively. The first two isolates are pathogenic stains while the latter two are considered as GRAS (Generally Recognized As Safe). Fibrinolytic activity of E. faecalis, characterized and designated as BRCA-5, reached a maximum, when the producer was cultivated in Ml7 broth supplemented with 1.0% glucose for 5 h at 37$^{\circ}C$ with shaking at 180 rpm. Compared to commercial fibrinolytic enzymes, the cell-free culture supernatant of 5. faecaiis BRCA-5 showed stronger activity than plasmin and streptokinase, but similar degree of specific activity as nattokinase and urokinase, aud it also demonstrated anticoagulant and antiplatelet activity ex vivo. These features of E. faecalis make it an attractive agent as a biomaterial for health-promoting foods.

• 한국세라믹학회지
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• 제22권6호
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• pp.80-86
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• 1985

Aluminum nitride (AlN) was synthesized from aluminum (Al) powders as a starting material in the tempe-rature range of 450~1, 15$0^{\circ}C$ in the presence of 90% $N_2$-10%$H_2$ gases. The thermogravimentric analysis showed that the nitridation of Al powders started at about 43$0^{\circ}C$ and escalated greatly from 53$0^{\circ}C$. The scanning electron microcopic observation revealed that AlN crystals were different in shape with varying temperature of nitridation. The crystals of AlN which were formed in the lower temperature than the melting point of Al were spherical while those of AlN in the higher temperature were fibrous. The yield of AlN was determined quantitatively by both XRD method and weight gain between before and after the nitridation of Al compacts. It was considered that the former was available for the specimen which was made in the high nitriding temperature. But the latter was unavilable for the same one probably because of the volatile loss of Al in the higher temperature.

• Journal of Information Display
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• 제12권3호
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• pp.135-139
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• 2011

This paper presents the directly obtained rotational viscosity values of E7, which includes pentylcyanobiphenol, heptylcyanobiphenol, 4-cyano-4'-n-octyloxy-1,1'-biphenyl, and 4-cyano-4"-n-pentyl-1,1',1"-terphenyl, at various tempe using molecular dynamics computer simulation. The director mean squared displacement was achieved from the squared displacement of the mean director using the concept of the mean director of various nematic liquid crystals. The calculated values were compared with the experiment results that predicted a good agreement. Additional points that must be considered for further study are also discussed.

• 한국세라믹학회지
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• 제33권5호
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• pp.563-571
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• 1996

In order to fabricate solid electrolyte CaO-stabilized ZrO2 of high density sintered body economically 13 mol% CaO-stabilized ZrO2 powders were synthesized by the coprecipitation method. The characteristics and sintering behavior of fine powder were investigated. The precipitates has the specific surface area of 193 m2/g and apperaed to be fine and spherical primary particles with a size of approximately 5nm. The crystalliza-tion temperture of CaO-stabilized ZrO2 was 462$^{\circ}C$. The tetragonal phase was stable in the low calcining tempe-rature regions and the cubic zirconia solid solution was formed from above 120$0^{\circ}C$ through an intermediate stage of formation of CaZrO3 By introducing fine powders washed with alcohol and ball-milling process after calcination the sintered body was possible to attain the value of above 92% of the theoretical density at low temperature of 120$0^{\circ}C$.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1993년도 수공학연구발표회논문집
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• pp.3-26
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• 1993

I have briefly described some of the important advances in hydrosystems and to remark on the important scientific research priorities in hydrological sciences. We have concentrated on data collection systems, real-time control of hydrosystems, global climate change and decision support systems and GIS. In summary, I would like to stress the following points: - the advances in data collection systems, advanced methodologies for interfacion hydrologic, hydraulic, and optimization models through optimal control approaches; and the advances in decision support systems and GIS will allow the interfacing of all these technologies into some sophisticated and much needed tools for operating hydrosystems; - the ability to better understand the hydrologic processes and their relationships to other earth processes is important to understanding and modelling of the hydrologic cycle and its interactions with the ocean-atmosphere system; - and the solution to a better understanding of hydrologic sciences needs to be an international effort such as the GEWEX program briefly discussed above. I would like to thamk each of you for listening to my lecture and to once again thank those responsible for me being here today. Thank you.

• 한국세라믹학회지
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• 제33권7호
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• pp.809-815
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• 1996

When Li2O.2SiO2 glass was crystallized between the temperature of maximum nucleation and the temperature of maximum crystal growth it was found that the control of heating rate had serious effect on the crystallinity and microstructure and the greatly changed physical properties. Density and elastic modulus tends to increase but thermal expansion coefficient decreased with increased crystallinity. When heating rate between the tempe-rature of maximum nucleation and the temperature of maximum crystal growth was 10~5$0^{\circ}C$/hr. crystallinity was increased to result in the increment of strength. When nuclation was done at 44$0^{\circ}C$ for 5 hours and the temperature of crystal growth was held at 575$^{\circ}C$ strength was increased until crystallinity reached 65% and strength was decreased with higher crystallinity. These phenomena could be explained that even for the same crystallinity different heat rates resulted in different number and size of cracks.

• 한국지반공학회논문집
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• 제28권9호
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• pp.23-30
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• 2012

본 논문은 토석류 발생사면에서 불포화토의 침투해석을 연계 수행한 사면안정해석 연구결과이다. 2006년 강원도 인제군과 2010년 경기도 양평군에 위치한 2개소의 토석류 발생사면에 대하여 현장조사를 수행하고 붕괴발생부에서 채취한 시료로 tempe pressure cell을 이용한 함수특성곡선과 새로이 개발된 불포화토 직접전단시험기를 사용하여 불포화토의 전단강도 정수를 구하였다. 실험을 통해 획득한 물성과 토석류 발생 당시의 강우자료를 바탕으로 상용프로그램 SEEP/W를 사용하여 불포화토 침투 해석을 실시하고 그 결과와 연동하여 사면안정해석 프로그램 SLOPE/W를 사용하여 사면활동을 분석하였다. 본 연구 결과 집중강우에 의한 불포화토 지반에 강우침투의 영향으로 지하수위의 상승과 포화도의 증가로 사면안전율이 감소하여 사면활동이 발생한 것으로 나타났다. 이러한 연구 방법을 통하여 실제 강우특성을 고려한 불포화토의 사면안정해석을 실시하는 것이 토석류 발생사면의 거동특성 중 특히 발생시점을 확인할 수 있는 합리적인 방법이라 판단된다.