MOCVD에 의한 GaAs/AlGaAs 초격자 및 HEMT 구조의 성장

김무성,김용,엄경숙,김성일,민석기,Kim, Moo-Sung,Kim, Yong,Eom, Kyung-Sook,Kim, Sung-Il,Min, Suk-Ki 대한전자공학회 1990 전자공학회논문지 Vol. No.

MOCVD에 의하여 초격자 및 HEMT 구조를 성장하고 그 특성을 보고한다. GaAs/AlGaAs의 경우, 주기성(periodicity),계면 급준성, Al 조성 균일성을 경사연마 및 double crystal x-ray 측정에 의하여 확인하였고, 고립 양자우물의 양자효과(quantum size effect)에 의한 PL(photoluminescence) 스펙트럼을 관측하였다. 이 PL FWHM (full width at half maximum)과 우물 두께의 관계로 부터 계면 급준성이 1 monolayer fluctuation 정도인 초격자 구조가 성장되었음을 확인하였다. 한편, HEMT 구조의 경우에 헤테로 계면에 형성된 2차원 전자층의 존재를 C-V profile, SdH(shu-bnikov-de Haas)진동, 저온 Hall 측정을 통하여 확인하였다. 저온 Hall 측정에서 15K에서 sheet carrier density $5.5{\times}10^{11}cm^-2$,mobility $69,000cm^2/v.sec$, 77K에서 sheet carrier density $6.6{\times}10^{11}cm^-2$, mobility $41,200cm^2/v.sec$ 이었다. 또한 quantum Hall effect 측정으로 부터 잘 형성된 SdH 진동 및 quantized Hall plateau를 관측하였다. We developed the technologies of wuperlattice and HEMT structures grown by MOCVD, and their characterization. In the case of GaAs/AlGaAs superlattice, the periodicity, interface abruptness and Al compositional uniformity were confirmed through the shallow angle lapping technique and double crystal x-ray measurement. Photoluminesence spectra due to quantum size effect of isolated quantum wells were also observed. The heterojunction abruptness was estimated to be within 1 monolayer fluctuation by the analysis of the relation between PL FWHM(Full Width at Half Maximum) and well width. HEMT structure was successfully grown by MOCVD. The 2 dimensional electron gas formation at heterointerface in HEMT structure were evidenced through the C-V profile, SdH (Shubnikov-de Haas)oscillation and low temperature Hall measurement. Low field mobility were as high as $69,000cm^2/v.sec$ for a sheet carrier density of $5.5{\times}10^{11}cm^-2$ at 15K, and $41,200cm^2/v.sec$ for a sheet carrier density of $6.6{\times}10^{11}cm^-2$ at 77K. In addition, well defined SdH oscillation and quantized Hall plateaues were observed.

GaAs 집적회로 제조를 위한 에피 성장 연구

김무성,엄경숙,박용주,김용,김성일,조훈영,민석기,Kim, Moo-Sung,Eom, Kyung-Sook,Park, Young-Joo,Kim, Yong,Kim, Seong-Il,Cho, Hoon-Young,Min, Suk-Ki 한국재료학회 1993 한국재료학회지 Vol.3 No.6

Bulk반절연 기판 웨이퍼에 이온 주입법에 의한 기존의 GaAs집적회로 제작시 발생하는 문제점을 보완하고자 반절연 기판 위에 반절연성의 고저항 GaAs 에피층을 성장하는 연구를 수행하였다. 먼저 반절연 기판의 EPD분포를 조사하고, MOCVD와 MBE법을 이용하여 undeped GaAs반절연성 에피층을 성장시켜 실제 집적회로의 제작에 적합한지를 평가하였다. 평가방법은 반절연성 에피\ulcorner을 buffer층으로 성장시킨 에피 기판에 ungated FET를 제작하여, 이 반절연성 에피\ulcorner을 통한 누설전류를 측정하고, 또한 반절연 기판의 EP분호의 영향을 조사하였다. 누설 전류의 측정결과 비교적 주설 전류가 큰 1$\mu\textrm{m}$ 두께의 MOCVD시료에서도 270nA/mm로 FET의 pinch-off에는 영향을 주지 못하는 매우 작은 누설 전류 값을 나타내었다. 또한 누설전류의 분포가 반절연 기판의 EPD분포와 일치하는 것을 발견하여, 에피층의 quality에 기판의 결함이 미치는 영향을 확인하였다. MBE법으로 성장한 2$\mu\textrm{m}$ 두께의 undoped burrer층 시료는 휠씬 좋은 특성을 나타내었으며, 매우 균일하고 낮은 누설전류(40nA/mm)가 측정되었다. The growth of semi-insulating(SI) high resistant undoped GaAs epilayer has been studied to solve the problems ocurring when GaAs IC is fabricated by the widely used ion implantation directly into the SI GaAs substrate. The EPD ditribution of the SI substrates has been examined, and the suitability of the buffer layers grown by MOCVD and MBE, respectively, has been tested for IC fabrication through leakage current measurement. IJngated FET has been fabricated on the SI epilayer and leakage current through the buffer layer has been measured. In the case of MOCVD grown 1$\mu\textrm{m}$-thick buffer layer, the leakage current is as small as about 270nA/mm, and this value does not affect the pinch-off of FET. In this case, the epilayer quality is affected by the substrate defects because the leakage current distribution is coincided with the EPD distribution of the SI substrate. The 2$\mu\textrm{m}$-thick buffer layer grown by MBE, however, has the better quality, and shows the lower leakage current(40nA/mrn) and higher uniformity.

Discovery of Spathius ibarakius Belokobylskij et Maeto (Hymenoptera: Braconidae) as a Larval Ectoparasitoid of Citrus Longhorned Beetle in Korea

김무성,이혜린,구덕서,김일권,홍기정,Kim, Moo-Sung,Lee, Hye-Lin,Ku, Deok-Seo,Herard, Franck,Gould, Juli R.,Williams, David W.,Kim, Il-Kwon,Hong, Ki-Jeong Korean Society of Applied Entomology 2016 한국응용곤충학회지 Vol.55 No.3

Spathius exarator의 종 그룹에 속하는 S. ibarakius Belokobylskij et Maeto가 한반도에서 알락하늘소(Anoplophora chinensis)의 1령과 2령 유충에 외부기생하는 것으로 확인되었다. 산란유인목을 이용하여 유리알락하늘소와 알락하늘소의 기생봉을 탐색하는 과정에서 이 고치벌이 발견되었다. 이 고치벌의 진단형질과 수컷의 특징, 삽화 및 한반도에 분포하는 종들의 기주목록을 함께 제공하였다. Spathius ibarakius Belokobylskij et Maeto, which belongs to the Spathius exarator species group (Hymenoptera: Braconidae: Doryctinae) was found as an ectoparasitoid of the first- and second-instar larvae of the citrus longhorned beetle, Anoplophora chinensis ($F{\ddot{o}}rster$) from Gwangneung, Pocheon, Korea. The discovery of this braconid wasp was made during the survey for parasitoids of the Asian and citrus longhorned beetles by using the sentinel log method. We herein describe diagnostic characters of S. ibarakius, including those of the male, and also provide illustrations. In addition, we present a host list of Korean species belong to genus Spathius.

Isolation of Thermostable ${\alpha}$-Amylase Hyperproducing Bacillus sp. No. 32H417 and Some Properties of the Enzyme

김무성,오평수,Kim, Moo-Sung,O, Pyong-Su 한국미생물 · 생명공학회 1991 한국미생물·생명공학회지 Vol.19 No.2

A bacterial strain NO. 32 which produced thermostable ${\alpha}$-amylase was isolated from soil and identified to genus of Bacillus. To enhance ${\alpha}$-amylase productivity, a successive mutation of Bacillus sp. No. 32 was attempted with treatment of N-methyl-N'-nitro-N-nitrosoguanidine (NTG). The resulting mutant, Bacillus sp. No. 32H417, which is risistant to refampicin and deficient in spore formation, produced about 90-fold high level of ${\alpha}$-amylase when compared with parental strain. The properties of the enzyme for thermostability were investigated. The optimal temperature and pH for enzyme reaction were 95$^{\circ}C$ and pH6.5, respectively, in the presence of 0.3mM $Ca^{2+}$ as an effective stabilizer.

당일 감마나이프수술 환자의 표준진료지침 개발을 통한 질 향상 효과 측정

김무성,하소영,배윤혁,정용태,김성태,이원희,고연주,Kim, Moo Seong,Ha, So Young,Bae, Yoon Hyuk,Jung, Yong Tae,Kim, Sung Tae,Lee, Won Hee,Go, Yeon Joo 한국의료질향상학회 2012 한국의료질향상학회지 Vol.18 No.1

Objectives : A protocol called "critical pathway" was developed to standardize the management of hospital patients the day after they underwent gamma knife radiosurgery. The quality of improvement in patient outcomes was evaluated. Methods : Critical pathway was developed, according to the regulations of the I hospital, by analyzing the medical records of 22 inpatients who underwent gamma knife surgery within the period from January to April 2011 on the day of the surgery. The study included a group of 22 patients admitted to the hospital the day after they underwent gamma knife radiosurgery, between July and September 2011. The control group included 22 patients who had surgery employing the same method within the period from May to June 2011. To measure the effects on quality improvement, the average length of stay, the execution rate of the hospital discharge notice system, daily hospital revenue, and the satisfaction of the patients and the medical team were assessed. The patient questionnaire employed a four-point Likert scale while the medical-staff questionnaire employed a five-point Likert scale. Result : The average length of stay was significantly shorter in the study group compared to the control group (2.3 days vs. 3.8 days, P<0.05). The execution rate of the hospital discharge notice system was higher in the study group (100% vs. 72%) than in the control group. Daily hospital revenues were higher by 264,178 Korean won in the study group when compared to the control group. The study group showed greater satisfaction of patients compared to the control group based on a four-point Likert scale (P<0.05). The study group showed greater satisfaction in medical team compared to the control group based on a five-point Likert scale (P<0.05). Conclusion : The development and implementation of a critical pathway protocol for hospital admission the day after gamma knife radiosurgery is an effective care process that improves the clinical quality.

신령버섯(Agaricus blazei Murill) 균사체내외 다당체의 면역활성효과

김무성,조홍범,Kim, Moo-Sung,Cho, Hong-Bum 한국미생물학회 2007 미생물학회지 Vol.43 No.4

신령버섯(Agaricus blazei Murill)의 액체 배양으로 다당체의 균사체외 분비를 유도하였으며, 버섯 균사체의 새포내 다당체와 세포외 분비 다당체의 면역증진활성을 in vitro 시험으로 비교하였다. 부분 정제된 세포내 다당체와 세포외 다당체의 총당 함량은 각각 85.6%와 95.3%였으며, ${\beta}$-glucan 함량은 각각 67.9%와 88.1%로 측정되었다. 면역활성 실험에는 시료의 닥 함량을 동일하게 맞추어 사용하였다. In vitro에서 균사체내외 다당체는 대식세포 주인 RAW 264.7을 활성화시켜 nitric oxide (NO) 생성을 농도 의존적으로 증가시켰으며, 각각 최대 53.9%, 53.1%의 비슷한 증가활성을 나타내었다. 또 균사채내외 다당체는 모두 RAW 264.7을 활성화시켜 염중성 cytokine류인 interleukin (IL)-$1{\beta}$, IL-6, tumor necrosis factor (TNF)-${\alpha}$의 생성을 증가시켰으며, 이때 3종의 cytokine 모두에서, 세포내 다당체에 비해 세포외 다당체를 처리했을때 저농도에서 높은 증가률을 나타내었다. 두 다당체는 in vitro 상에서 비장세포를 증식시키는 효과를 나타내었으며, 세포내 다당체가 농도 의존적으로 증식효과를 보인데 반해 세포외 다당체는 저농도에서 증식이 높았고, $250\;{\mu}g/ml$ 농도 이상에서는 더 높아지지 않았다. 두 다당체 모두 암세포인 B16F0 melanoma에 대한 직접적인 세포독성 효과는 나타내지 않았다. 신령버섯 균사체 배양으로 생성된 세포내외 다당체는 in vitro에서 모두 면역활성을 증가시키는 것으로 나타났으며 전반적으로 그 활성은 세포내 다당체보다 세포외 다당체가 우수한 것으로 판단되었다. This study was performed to compare in vitro immune enhancing effects of polysaccharides extracted from cultivated mycelia of Agaricus blazei Murill. Carbohydrate contents of semi-purified polysaccharides were 85.6% and 95.3%, while ${\beta}$-glucan conents were 67.9% and 88.1% for intracellular and extracellular polysaccharide, respectively. Samples were adjusted to the same in their carbohydrate contents before efficacy tests. Both intracellular and extracellular polysaccharide increased nitric oxide (NO) synthesis of macrophage RAW 264.7 in dose dependent manner, and the maximum increase rate was 53.9 and 53.1% in intracellular and extraceltular polysaccharide, respectively. The polysaccharides also increased synthesis of cytokines such as interleukin (IL)-$1{\beta}$, IL-6 and tumor necrosis factor (TNF)-${\alpha}$ in RAW 264.7. For all the 3 cytokines, the increase rate of synthesis was much higher in extracellular polysaccharide compared to intracellular polysaccharide, especially at low concentration. Both polysaccarides increased the proliferation of splenocytes in vitro, intracellular polysaccharide showed increase in dose dependent manner while extraceltular polysaccharide showed increase untill medium concentration ($250\;{\mu}g/ml$). They did not show direct cytotoxicity against cancer cells such as B16F0 melanoma. As results, it was regarded that the both intracellular and extracellular polysaccharide from A. blazei showed immune enhancing effects in vitro, but the activity is higher in extracellular polysaccharide compared to intracellular polysaccharide.

알팔파(Medicago sativa L.) 7개 품종(品種)의 생육(生育)에 미치는 근류균접종(根瘤菌接種)의 영향(影響)

김무성,Kim, Moo-Sung 한국토양비료학회 1975 한국토양비료학회지 Vol.8 No.1

현지기후풍토(現地氣候風土)에 적합할 것으로 생각되는 7품종(品種) Alfalfa (Washo, Ranger, Lahontan, Narragensett, Atlantic, Vernal, Moapa 69)의 건물생산량과 생육(生育)에 미치는 근류균접종효과에 관한 실험(實驗)을 비교적 척박한 토양(土壤)에 종자(種子) 30l에 근류균(根瘤菌) 6oz 비율로 도말하여 파종(播種) 1973-74년 2년간(年間) 실시하였다. 1. 공시된 품종(品種)에서 근류균(根瘤菌)을 접종(接種)한 구(區)가 접종(接種)하지 않은 구(區)에 비하여 초장(草長) 및 건물량(乾物量)에 있어서 현저한 증가를 보였다. 2. 1973년(年) Pot 시험에서 접종구(接種區)의 건물생산량은 Moapa 69> Vernal> Lahontan> Washoe> Atlantic> Narragensett> Ranger 의 순(順)이었다. 3. 다음해 포장(圃場)에 이식(移植)한 후에는 접종(接種)과 무접종간(無接種間)의 건물생산량에 차이가 없었다. 총건물(總乾物) 생산량은 Washoe> Lahontan> Moapa 69> Ranger> Narrangensett> Vernal> Atlantic의 순(順)이었다. Effect of inoculation trial on plant height and dry matter yield of seven alfalfa varieties (Medicago sativa L. var. Washoe, Ranger, Lahontan, Narragensett, Atlantic, Vernal, and Moapa 69) which are considered to be well adapted in these areas were conducted during 1973-1974 in a relatively poor soil at the field station in Kyung Hee University. Root nodule bacteria: Rhizobium meliloti (Noculator Northrup Kings Co. Ltd) was applied at a rate to provide 6 oz/30l of alfalfa seeds. Seven varieties were seeded in pots on May 31, 1973 and in second year, they were transplanted in field. 1. Dry matter yield and plant height of all inoculation plots were significantly greater than those of the no inoculation plots in all varieties. 2. In the 1973, dry matter yield of inoculation plot a in pot experiment was in the order of Moapa 69> Vernal> Lahontan> Washoe> Atlantic> Narragensett> Ranger. 3. There was no difference in dry matter yield between with and without-inoculation after transplanted in a field in the second year (1974). Total dry matter yield of varieties was in the order of Washoe> Lahontan> Moapa 69> Ranger> Narragensett> Vernal> Atlantic.

KOSPI 200 지수옵션시장에서의 투자심리와 정보효율성 -날씨변수를 중심으로-

김무성 ( Moo Sung Kim ),강태훈 ( Tae Hun Kang ),김상현 ( Sang Hyeon Kim ) 한국금융공학회 2008 금융공학연구 Vol.7 No.1

본 연구는 날씨변수를 이용하여 시장참가자들의 사회 전반적인 투자심리의 영향이 KOSPI 200 지수옵션시장에 반영되어 있는가를 분석하였다. 분석결과 상대습도, 운량, (체감)기온과 평균풍속은 옵션시장의 약정금액에 영향을 미치는 것으로 나타나며, 평균풍속은 옵션가격으로부터 추론한 상태가격밀도의 왜도에 영향을 미치는 것으로 나타났다. 그러나 이러한 결과의 원인이 시장의 비효율성보다는 오히려 날씨가 기업의 내재가치에 관한 정보변수로서 투자자의 의사결정에 영향을 미쳤을 가능성이 존재할 수 있다. 따라서 두 가지 상충되는 영향을 보다 명확하게 구분하기 위해, 날씨로 인한 사회 전반적인 투자심리(social mood)가 미래 불확실한 상황에 대하여 투자자가 기대하는 주관적인 확률분포에 영향을 미치는가를 분석하였다. 분석결과 날씨가 KOSPI 200 지수옵션시장에 영향을 미치는 것은 날씨로 인한 심리적인 영향이기 보다는 날씨가 기업의 내재가치에 영향을 미치는 정보변수로서 투자자의 의사결정에 반영되었을 가능성이 높은 것으로 나타났다. 따라서 내재왜도와 약정금액에 대한 날씨변수의 영향은 심리적인 요인이 아닌 날씨가 내재가치에 미치는 영향을 반영하여 미래지수의 상승과 하락에 대한 기대 즉, 특정행사가격의 옵션에 대한 선택과 구체적인 투자금액의 결정에 영향을 미치는 것으로 나타났다. This article empirically analyzes whether weather conditions that serve as social mood proxies affect the financial market prices and are correlated with people`s subjective evaluation of future probabilities. We find that humidity levels, cloud cover, temperature and the average velocity of the wind Granger causes the trading number of KOSPI 200 index options and the average velocity of the wind Granger causes the skewness of the state price density implied in the KOSPI 200 index options market price. But there is some possibility that the causes of these results may be that weather conditions influence not the social emotion of decision markers but the intrinsic value of the companies. To accurately investigate the cause of the results, we test whether mood affects the subjective beliefs of capital market participants. Our statistical analysis suggests that bad mood states are not characterized by investors placing higher probabilities on adverse events. Therefore, with respect to the weather conditions that serve as social mood proxies, KOSPI 200 index (options) markets are efficient during the sample period of this study.

플레넘 팬에서 입구 간극의 영향 대한 수치해석적 연구

김무성(Moo Sung Kim),주원구(Won-Gu Joo) 한국유체기계학회 2016 유체기계 연구개발 발표회 논문집 Vol.2016 No.11

내재정보를 이용한 가격동학 특성에 관한 연구

김무성 ( Moo Sung Kim ),강태훈 ( Tae Hun Kang ) 한국파생상품학회 2007 선물연구 Vol.15 No.2