• 한국관광식음료학회지:관광식음료경영연구
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• 제13권2호
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• pp.129-147
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• 2002

본 실험은 $\beta$-cyclodextrin을 사용하여 cholesterol을 제거한 균질우유로부터 cholesterol이 제거된 치즈 제조의 조건을 규명하고, 그 조건에 따라 제조된 cheese의 특성 및 관능 검사를 함으로써 cholesterol이 제거된 cheese의 개발 가능성을 조사하는데 그 목적을 두고 있다. 치즈 제조에 적합하다고 사료되는 낮은 균질압력에서 효과적인 cholesterol 제거율을 알아보기 위해 균질압력 0, 250, 500, 750, 1000psi(0-70kg/$cm^2$와 균질온도 40, 50, 60, $70^{\circ}$ 그리고 $\beta$-cyclodextrin 첨가량 1.0, 1.5 2.0% 등의 3가지 조건에 따라 우유를 처리하여 cholesterol이 제거된 cheese의 제조에 적합한 조건으로는 균질압력 1000psi(70kg/$cm^2$), 균질 온도 $70^{\circ}$$0^{\circ}C$, $\beta$-cyclodextrin 첨가량 2.0%로 관찰되었다. 따라서 균질온도는 $70^{\circ}$로 정하고, 균질압력을 400, 600, 900, 1200si(0,- 91kg/$cm^2$)로, $\beta$-cyclodextrin 첨가량을 1과 2%로 처리하여 제조한 cheese와 균질을 하지 않고 $\beta$-cyclodextrin의 처리를 하지 알은 control 치즈간의 수율, cholesterol 제거율, mettability, stretchability, oiling off, 조직검사, 관능검사 등의 실험을 실시하여 control 치즈와 가장 유사한 cholesterol이 제거된 cheese 개발의 가능성을 시도하였고, 그 결과는 다음과 같다. 1. Cholesterol을 제거한 cheese의 제조에서 최적조건은 균질압력 1200psi(70kg$cm^2$), 균질온도 $70^{\circ}$, $\beta$-cyclodextrin 첨가량 2%였으며, 이때 우유의 cholesterol의 제거율이 86.05%로 가장 높게 나타났다. 2. Cholesterol을 제거한 cheese들의 수율은 모두 12.53%(control 10.54%) 이상으로 균질 처리가 cheese의 수율을 18.88%이상 향상시키는 것으로 나타났다. 3. 유지방 함량 23.80%인 control 치즈의 cholesterol 함량은 81.47mg/100g이었고, 균질압력 1200psi(91kg/$cm^2$)에 $\beta$-cyclodextrin 2%를 첨가한 cheese에서는 cholesterol 함량이 20.15mg/100g으로 cholesterol 제거율이 75.27%로 가장 높게 나타났다. 4. Meltability는 균질압력 1200psi(91kg/$cm^2$)에 $\beta$-cyclodextrin 1과 2%로 처리한 치즈에서 2.25cm(control 3.34cm)로 가장 낮았으며, 균질압력이 증가할수록 meltability가 감소하여 치즈의 품질을 저하시켰다. 5. Control 치즈의 stretchability는 30cm 이상 늘어나 가장 양호한 수치인 5점을 나타낸 반면, cholesterol을 제거한 cheese에서는 5~10cm 사이를 나타내어 2점으로 stretchability가 저하된 것을 볼 수 있었다. 6. Oiling off는 균질압력 1200psi(91kg/$cm^2$)에 $\beta$-cyclodextrin 1과 2%로 처리한 치즈에서 0.03%(control 2.46%)로 가장 낮았으며, 균질압력이 증가할수록 oiling off는 감소하여 치즈의 외관상 품질을 향상시켰다. 7. Hardness, gumminess, chewiness는 균질압력 1200psi(91kg/$\textrm{cm}^2$)에 $\beta$-cyclodextrin 1%로 처리한 치즈에서 각각 나타내었으며, control과 cholesterol을 제거한 치즈들 사이에 유의적 (p<0.05) 차이를 보이며 큰 감소를 나타내었다. 8. Cholesterol을 제거한 cheese의 appearance와 flavor는 1200psi (91kg/$cm^2$)일 때 각각 가장 높은 5,56과 4.63(control 4.00)으로 균질압력이 증가하면서 향상되었으며, texture score는 균질압력 1200psi(91kg/$cm^2$)에 $\beta$-cyclodextrin 2%일때 1.22(control 4.00)로 가장 낮은 수치를 나타내었고, 균질이 cheese의 texture score를 상당히 저하시키는 것을 알 수 있었다. 9. 이 실험결과, 균질압력 1200psi(91kg/$cm^2$)에 $\beta$-cyclodextrin 2% 첨가한 cheese에서 cholesterol 제거율이 75.27%로 가장 높았으며, 균질처리가 cheese의 수율, oiling off, appearance score, flavor scope 등을 향상시켰고, meltability, stretchability, hardness, gumminess, chewiness, texture score를 저하시키는 것으로 나타나 cholesterol이 상당부분 제거된 cheese의 개발 가능성이 관찰되었다.

• 재무관리연구
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• 제24권2호
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• pp.41-79
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• 2007

본 논문은 주가지수 선물과 옵션의 만기일이 주식시장에 어떠한 영향을 미치는가에 대한 분석을 통해 한국주식시장에서 만기일 효과가 존재하는지를 검증한다. 주가지수를 이용한 기존의 논문과는 달리 만기일에 현물 주식시장의 움직임을 개별 종목별로 분석했다는 점에서 본 논문은 차별성을 지닌다. 주가지수는 시장 움직임의 평균으로 개별 종목의 고유한 특성을 반영하지 못하기 때문에 주가지수를 이용한 분석은 만기일 효과를 해석하고 그 원인을 분석하는데 한계를 지니고 있다. 분석 결과 한국주식시장에서 선물 만기일 효과는 분명히 존재하지만, 옵션 만기일 효과는 뚜렷하지 않은 것으로 드러났다. 선물 만기일에 KOSPI 200 지수와 개별 종목은 가격상승 압력이 존재하고, 변동성과 거래량이 증가하며, 만기일 다음날 수익률은 반전하는 경향이 있는 것으로 나타났다. 그러나 비교표본인 NON-KOSPI 200 지수와 개별 종목에서 만기일 효과가 존재한다고 할 만한 증거를 찾지 못했다. 만기일 효과가 시장 전체적으로 나타나는 것처럼 보이지만 KOSPI 200에 속하는 대규모 기업에 한정되며, 장 후반에 집중적으로 나타난다는 사실은 프로그램 매매와 만기일의 결제제도가 만기일 효과의 간접적 원인임을 시사한다. 또한 만기일 다음날 가격이 반전하는 현상이 KOSPI 200에 속하는 대규모 기업에 한정되어 나타나는 사실은 만기일 효과가 새로운 정보의 반영에 의한 정보 효과(information effects)가 아니라 일시적 거래불균형에 의한 유동성 효과(liquidity effects)임을 보여주는 증거가 된다.

• 한국식품과학회지
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• 제42권4호
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• pp.481-487
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• 2010

본 연구에서는 열대과일 리치의 부산물인 과피를 기능성 식품 산업 소재로써의 활용가능성을 알아보기 위해 영양화학성분 분석, 항산화 및 신경세포 보호효과에 대해서 조사하였다. 리치 과피의 일반성분은 수분 0.11%, 조단백질 13.97%, 조지방 0.04%, 조회분 0.33% 및 가용성 무질소물 85.52%이었다. 주요 무기성분으로는 K 989.35 mg/100 g, Ca 399.81 mg/100 g 및 P 264.65 mg/100 g이었으며, 용매별 리치 과피의 총 페놀 함량을 측정한 결과는 열수 추출물 8.02 mg/g, 50% 메탄올 추출물 12.28 mg/g,으로 각각 나타났다. 주요 아미노산으로는 proline이 672.59 mg/100 g으로 가장 높은 함량을 차지하였다. 주요 지방산으로는 palmitic acid(42.86%), stearic acid(14.88%)이었으며, 리치 과피의 DPPH와 ABTS radical 소거활성을 측정한 결과 열수 추출물에 비해 50% 메탄올 추출물의 소거활성이 상대적으로 높게 나타났다. 특히 열수와 50% 메탄올 추출물의 최대 처리농도 5 mg/mL에서 DPPH와 ABTS radical 소거활성은 각각 17.68, 37.35%와 39.79, 50.33%로 나타났다. FRAP assay을 이용한 항산화 활성은 농도의존적인 경향을 보였으며, 열수 추출물에 비하여 50% 메탄올 추출물이 상대적으로 우수하였다. MTT, LDH assay를 통한 신경세포 보호효과를 측정한 결과 MTT 실험에서는 리치 과피 추출물의 모든 농도에서 positive control로서의 vitamin C와 유사한 세포 생존율을 나타냈고, LDH 실험에서는 추출물에 의한 농도 의존적 효소 방출량 감소가 관찰되었고, 특히 최대 $500\;{\mu}g/mL$ 농도에서는 50% 메탄올 추출물이 열수추출물 보다 약 1.7배 가량의 방출량 저해 효과가 나타났다. 본 연구결과를 종합해 볼 때, 우수한 영양 구성 성분과 physiological phenolics를 함유한 리치 과피 추출물은 항산화 및 산화적 스트레스로부터 신경세포 보호효과를 나타내면서 퇴행성 신경질환 등을 예방할 수 있는 기능성 산업소재로서의 가치가 높다고 판단된다.

• 한국어병학회지
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• 제11권1호
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• pp.51-60
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• 1998

본 연구는 내수면 양식 어류에 백점충, Ichthyophthirius multifiliis를 인위 감염시켜 감염 특성 및 어체내 충체 발달상을 밝히고자 하였다. 어종별(무지개 송어, 메기, 이스라엘 잉어), 수온별($15^{\circ}C$, $18^{\circ}C$, $21^{\circ}C$) 및 충체 발달 단계별(trophont, protomont, theront) 인위 감염 시험 결과, 어종별로는 무지개 송어 시험구에서, 수온별로는 $18^{\circ}C$ 시험구에서 그리고 충체 발달 단계별로는 theront 시험구에서 양성적인 인위 감염을 확인할 수 있었다. 그리고 theront 농도별에 있어서는 어체당 1000개체의 theront가 감염을 양성적으로 유도할 수 있는 것으로 조사되었으며 어체당 1500개체 이상의 theront는 무지개 송어치어에 100%의 감염을 유도하였다. 수온 $18^{\circ}C$의 인위 감염된 무지개 송어에서 7일 동안 어체내 충체의 발달 과정을 조사한 결과, 충체는 시간이 경과함에 따라 연속적인 발달을 행하여 크기가 증대되었으며 감염 3일째부터는 성숙되는 것으로 확인되었다. 그리고 총체의 형태학적 변화는 감염 2일째에는 구부장치가 기능적으로 발달하기 시작한 것을 볼 수 있었고, 감염 4일째부터는 수축포가 현저히 발달되기 시작하였으며 감염 6일째는 이들의 수가 현저히 증가한 것을 확인할 수 있었다. 그리고 감염 기간이 경과함에 따라 충체는 숙주의 아가미 일차 새변의 입새 동맥쪽으로 이동하는 경향을 나타내었다.

• 재무관리논총
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• 제3권1호
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• pp.233-265
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• 1996

We examine the impact of public and private information on price movements using the thirty DJIA stocks and twenty-one NASDAQ stocks. We find that the standard deviation of daily returns on information days (dividend announcement, earnings announcement, insider purchase, or insider sale) is much higher than on no-information days. Both public information matters at the NYSE, probably due to masked identification of insiders. Earnings announcement has the greatest impact for both DJIA and NASDAQ stocks, and there is some evidence of positive impact of insider asle on return volatility of NASDAQ stocks. There has been considerable debate, e.g., French and Roll (1986), over whether market volatility is due to public information or private information-the latter gathered through costly search and only revealed through trading. Public information is composed of (1) marketwide public information such as regularly scheduled federal economic announcements (e.g., employment, GNP, leading indicators) and (2) company-specific public information such as dividend and earnings announcements. Policy makers and corporate insiders have a better access to marketwide private information (e.g., a new monetary policy decision made in the Federal Reserve Board meeting) and company-specific private information, respectively, compated to the general public. Ederington and Lee (1993) show that marketwide public information accounts for most of the observed volatility patterns in interest rate and foreign exchange futures markets. Company-specific public information is explored by Patell and Wolfson (1984) and Jennings and Starks (1985). They show that dividend and earnings announcements induce higher than normal volatility in equity prices. Kyle (1985), Admati and Pfleiderer (1988), Barclay, Litzenberger and Warner (1990), Foster and Viswanathan (1990), Back (1992), and Barclay and Warner (1993) show that the private information help by informed traders and revealed through trading influences market volatility. Cornell and Sirri (1992)' and Meulbroek (1992) investigate the actual insider trading activities in a tender offer case and the prosecuted illegal trading cased, respectively. This paper examines the aggregate and individual impact of marketwide information, company-specific public information, and company-specific private information on equity prices. Specifically, we use the thirty common stocks in the Dow Jones Industrial Average (DJIA) and twenty one National Association of Securities Dealers Automated Quotations (NASDAQ) common stocks to examine how their prices react to information. Marketwide information (public and private) is estimated by the movement in the Standard and Poors (S & P) 500 Index price for the DJIA stocks and the movement in the NASDAQ Composite Index price for the NASDAQ stocks. Divedend and earnings announcements are used as a subset of company-specific public information. The trading activity of corporate insiders (major corporate officers, members of the board of directors, and owners of at least 10 percent of any equity class) with an access to private information can be cannot legally trade on private information. Therefore, most insider transactions are not necessarily based on private information. Nevertheless, we hypothesize that market participants observe how insiders trade in order to infer any information that they cannot possess because insiders tend to buy (sell) when they have good (bad) information about their company. For example, Damodaran and Liu (1993) show that insiders of real estate investment trusts buy (sell) after they receive favorable (unfavorable) appraisal news before the information in these appraisals is released to the public. Price discovery in a competitive multiple-dealership market (NASDAQ) would be different from that in a monopolistic specialist system (NYSE). Consequently, we hypothesize that NASDAQ stocks are affected more by private information (or more precisely, insider trading) than the DJIA stocks. In the next section, we describe our choices of the fifty-one stocks and the public and private information set. We also discuss institutional differences between the NYSE and the NASDAQ market. In Section II, we examine the implications of public and private information for the volatility of daily returns of each stock. In Section III, we turn to the question of the relative importance of individual elements of our information set. Further analysis of the five DJIA stocks and the four NASDAQ stocks that are most sensitive to earnings announcements is given in Section IV, and our results are summarized in Section V.

• 대한치과기공학회지
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• 제19권1호
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• pp.21-35
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• 1997

Au 함량이 20% 미만인 Au-Ag-Pd합금의 기초합금인 Ag-Pd-Cu 3원계 합금의 시효경화 특성을 규명할 목적으로 20wt% Pd 및 20wt% Cu의 용질농도구성비가 1이 되는 3원 합금과 여기에 2wt% Au의 첨가합금에 미치는 석출상의 영향을 분석, 조사하여 아래와 같은 결론을 얻었다. Ag-20wt% Pd-20wt% Cu 3원 함금은 ${\alpha}$의 단일상에서 Ag-rich의 ${\alpha}2$상 및 PdCu규칙상에 의하여 경화반응이 진행되며 연속승온과정에서 $100{\sim}300^{\circ}C$의 경도증가와 $300{\sim}500^{\circ}C$의 경도감소의 2단계 경화특성이 얻어졌다. 연속승온시효과정은 Au첨가에 관계없이 2단계의 석출반응이 저온영역에서는 stage I, stage II로 나타나고 stage I은 고온에서의 소입에 의해 도입된 과잉공공의 이동 및 소멸에 의한 반응이고 stage II는 평형농도의 공공확산에 의한 반응에 대응하였다. 또한 본 합금의 시효석출과정은 ${\alpha}\to{\alpha}+{\alpha}2+PdCu\to{\alpha}_1+{\alpha}_2+PdCu$이고 최대 경화는 ${\alpha}_1,\;{\alpha}_2$, PdCu의 3상공존구역에서 나타났다. 이들 석출반응은 입계반응이고 반응의 진행과 함께 경도값은 상승하며 경화능에 직접적으로 기여하였다. 또한 석출상은 미세한 lamella조직의 nodule을 나타내고 이들 ${\alpha}_1,\;{\alpha}_2$ 및 PdCu상과의 미세한 혼합상의 형성이 시효경화능에 기여하는 주된 원인이 되었다. 과시효는 lamella의 조대화와 PdCu상의 ${\alpha}_2$상으로의 용해에 따른 정량적 감소에 대응하였다. 본 합금의 시효열처리 온도는 $450^{\circ}C$가 적절하며 $1{\sim}120min$ 시효시간에 걸쳐서 소정의 경화특성을 얻을 수 있었다.

• 동서간호학연구지
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• 제5권1호
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• pp.90-101
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• 2000

The study attempts to examine the degree of cognition and demand on health promotion center of oriental nursing. It puts unique nursing intervention using traditional health promotion connected with oriental medicine to practical use for residents' health promotion and prevention of disease. With the study design of cross-sectional descriptive study, 516 residents who live in 26 Dongs, Dongdaemoon-gu were selected. The tool of study consists of 30 questions which the study team made for the degree of cognition and demand on health promotion center of oriental nursing. Cronbach's $\alpha$ in the degree of cognition was .8028. Collection of research data had been done from October 1 to October 30, 1999 with help of Dongdaemoon-gu office after pretest from 20 residents. Collected data were analyzed into the number and percentage in the characteristic of a subject and connected with demand on the establishment of center, the mean and the standard deviation in the degree of cognition and F-tests in the difference of the degree of cognition by characteristics. The results were as follow; 1) The characteristic of subject of this study was male 50.6%, and average age was 38.5 years old and 30-39 years old occupied the highest percentage with 31.6%. The married were 71.8%, over high school graduates was 85.6%, monthly income from 500 thousand won to 2 million won was 86.1%. 50.8% was the type living with parents, children and sibling. 2) When they were sick, the institution which residents used at first was a pharmacy(69.2%) and hospital(27.5%), but oriental medicine hospital was just 1.4%. As for subjective health condition, 82.5% answered over average, and 28.7% answered that they had chronic illness such as arthritis, chronic digestion problem, hypertension and so on. As for information collection on health, mass communication(34.9%) and medically concerned people(28.1%) occupied relatively high rate. Free health diagnosis system(36.8%) and establishment of health promotion center(31.5%) among welfare programs that residents want to enjoy were high ranked. The rate using a special institution for health was 17.8%, and among these institutions, the rate using aerobic exercises, health center(7.0%) and steamed room(5.4%) was high. Besides, other institutions such as breathing at the abdomen, finger-pressure therapy, meridian massage, foot massage, and so on were being used. 3) As the average of the degree of cognition on health promotion center of oriental medicine was 2.92, the degree of cognition was medium. The description, "health promotion center of oriental medicine is necessary for health keeping of healthy people, including people who have a problem in health" showed the highest degree of cognition(3.04, ${\pm}0.64$). 4) As for the intention on using health promotion center of oriental nursing, 61.4% said "yes", "no" was just 1.4%. The services that people relatively high wanted to be served from the center were measures reducing stress(68.0%) (relaxation therapy, meditation, breathing at the abdomen and so on), acupuncture(66.5%), finger-pressure(61.6%), moxibustion(57.6%), meridian massage(44.2%), postpartum care(40.3%) and so on. 5) As for the degree of cognition on the establishment of health promotion center of oriental nursing by characteristics of subject, there was significant difference(F=4.03, p=.046) between male(3.01) and female(2.91). But there was no significant difference by age, marital status, level of educational achievement and monthly income. As the above result, cognition on the establishment of health promotion center of oriental nursing was relatively low because people were not familiar with about the health promotion center of oriental nursing yet. However once the center will be established, the degree of demand on the center will be relatively high. So positive advertisement will be necessary, and the management of useful programs will be also required in order to make people recognize the advantage when they actually will use the center. On the other hand, as the subject of the study consists of many young people of below 30, the health problem came to be low. And in the case of sampling, the study using random sampling that can represent population will be required.

• 지능정보연구
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• 제23권4호
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• pp.147-168
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• 2017

오래 전부터 학계에서는 정확한 주식 시장의 예측에 대한 많은 연구가 진행되어 왔고 현재에도 다양한 기법을 응용한 예측모형들이 연구되고 있다. 특히 최근에는 딥러닝(Deep-Learning)을 포함한 다양한 기계학습기법(Machine Learning Methods)을 이용해 주가지수를 예측하려는 많은 시도들이 진행되고 있다. 전통적인 주식투자거래의 분석기법으로는 기본적 분석과 기술적 분석방법이 사용되지만 보다 단기적인 거래예측이나 통계학적, 수리적 기법을 응용하기에는 기술적 분석 방법이 보다 유용한 측면이 있다. 이러한 기술적 지표들을 이용하여 진행된 대부분의 연구는 미래시장의 (보통은 다음 거래일) 주가 등락을 이진분류-상승 또는 하락-하여 주가를 예측하는 모형을 연구한 것이다. 하지만 이러한 이진분류로는 추세를 예측하여 매매시그널을 파악하거나, 포트폴리오 리밸런싱(Portfolio Rebalancing)의 신호로 삼기에는 적합치 않은 측면이 많은 것 또한 사실이다. 이에 본 연구에서는 기존의 주가지수 예측방법인 이진 분류 (binary classification) 방법에서 주가지수 추세를 (상승추세, 박스권, 하락추세) 다분류 (multiple classification) 체계로 확장하여 주가지수 추세를 예측하고자 한다. 이러한 다 분류 문제 해결을 위해 기존에 사용하던 통계적 방법인 다항로지스틱 회귀분석(Multinomial Logistic Regression Analysis, MLOGIT)이나 다중판별분석(Multiple Discriminant Analysis, MDA) 또는 인공신경망(Artificial Neural Networks, ANN)과 같은 기법보다는 예측성과의 우수성이 입증된 다분류 Support Vector Machines(Multiclass SVM, MSVM)을 사용하고, 이 모델의 성능을 향상시키기 위한 래퍼(wrapper)로서 유전자 알고리즘(Genetic Algorithm)을 이용한 최적화 모델을 제안한다. 특히 GA-MSVM으로 명명된 본 연구의 제안 모형에서는 MSVM의 커널함수 매개변수, 그리고 최적의 입력변수 선택(feature selection) 뿐만이 아니라 학습사례 선택(instance selection)까지 최적화하여 모델의 성능을 극대화 하도록 설계하였다. 제안 모형의 성능을 검증하기 위해 국내주식시장의 실제 데이터를 적용해본 결과 ANN이나 CBR, MLOGIT, MDA와 같은 기존 데이터마이닝 기법들이나 인공지능 알고리즘은 물론 현재까지 가장 우수한 예측 성과를 나타내는 것으로 알려져 있던 전통적인 다분류 SVM 보다도 제안 모형이 보다 우수한 예측성과를 보임을 확인할 수 있었다. 특히 주가지수 추세 예측에 있어서 학습사례의 선택이 매우 중요한 역할을 하는 것으로 확인 되었으며, 모델의 성능의 개선효과에 다른 요인보다 중요한 요소임을 확인할 수 있었다.

• Tuberculosis and Respiratory Diseases
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• 제58권1호
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• pp.31-42
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• 2005

배 경 : peroxiredoxins는 거의 모든 생명체에 공통적으로 보존되어 있으며, 최근에 발견된, 특이한 peroxidases로 인체에서 6가지 동위효소가 알려져 있으며, 산화스트레스에 대한 방어역할을 담당하고, $H_2O_2$신호전달 과정에서 중요한 조절 역할을 한다. peroxiredoxin은 $H_2O_2$ 처리 과정 중에서 자신이 산화되어 불활성화 되는데, 산화된 후 다시 재생되는 것으로 보고되나 그 생리적은 의미는 분명하지 않다. 이에 저자들을 폐상 피세포주, 대식세포주, 폐포모세혈관 내피세포주 및 기타 섬유모세포주 들에서 $H_2O_2$ 에 의한 Prx의 산화과정과 재생을 알아보고자 하였다. 방 법 : 수술 환자에서 적출한 정상 폐조직과, 세포주로는 평상시 산화 스트레스에 노출이 많을 것으로 예상되는 세포들로써, 폐포상피세포의 I 형 및 II 형 세포에서 기원한 A549, WI 26, Raw 264.7, Rat2,및 폐포 모세혈관 내피세포주 등을 이용하여 이를 $50{\mu}M$. $100{\mu}M$, $500{\mu}M$ 의 $H_2O_2$로 산화시켜 불활성화 한 후, 추적관찰 하였으며, 시간대 별로(0. 10, 30, 60, 120, 240, 480 분) 수확하여, 이를 1차원 non-reducing SDS-PAGE 및 2차원 전기영동로 분리 후, silver stain 과 Western blot으로 분석 하였다. 결 과 : 1. 실험에 사용된 모든 세포주에서, $H_2O_2$ 농도에 비례하여 peroxiredoxin I, II, III 의 불활성화를 관찰할 수 있었고, 10분에 최고로 불활성화되었다. 2. 산화된 이후, 30분경부터 peroxiredoxin 의 재생이 관찰되기 시작 하였으며, 2시간 이후부터 확연하였다. 3. 다시 재생된 peroxiredoxin은 $H_2O_2$투여로서, 다시 불활성화되어, 재생된 Prx 가 활성을 지닌 단백질임을 알 수 있었다. 4. 재생의 속도는 사용된 세포주마다 차이가 있었으며 (A549 >Raw 264.7 >$Rat_2$ >WI26), 단백질 합성억제제인 cycloheximide ($10{\mu}g/ml$) 존재 하에서도 변함 없이 관찰되었다. 결 론 : 세포 내에는 산화되어 불활성화된 peroxiredoxin을 재생하는 체계가 존재 하며, 이는 활성부위 cysteine을 갖는 다른 단백질에도 공통적으로 적용될 수 있는 분자 스위치일 가능성이 높으며, 산화에 의한 신호전달과정이나, 질병 모델에서 Prx 단백의 재생 체계의 이상과 병인에 관한 추가적인 연구가 필요할 것으로 사료된다.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 1993년도 한국우주과학회보 제2권2호
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• pp.17-17
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• 1993

The wall shear stress in the vicinity of end-to end anastomoses under steady flow conditions was measured using a flush-mounted hot-film anemometer(FMHFA) probe. The experimental measurements were in good agreement with numerical results except in flow with low Reynolds numbers. The wall shear stress increased proximal to the anastomosis in flow from the Penrose tubing (simulating an artery) to the PTFE: graft. In flow from the PTFE graft to the Penrose tubing, low wall shear stress was observed distal to the anastomosis. Abnormal distributions of wall shear stress in the vicinity of the anastomosis, resulting from the compliance mismatch between the graft and the host artery, might be an important factor of ANFH formation and the graft failure. The present study suggests a correlation between regions of the low wall shear stress and the development of anastomotic neointimal fibrous hyperplasia(ANPH) in end-to-end anastomoses. 30523 T00401030523 ^x Air pressure decay(APD) rate and ultrafiltration rate(UFR) tests were performed on new and saline rinsed dialyzers as well as those roused in patients several times. C-DAK 4000 (Cordis Dow) and CF IS-11 (Baxter Travenol) reused dialyzers obtained from the dialysis clinic were used in the present study. The new dialyzers exhibited a relatively flat APD, whereas saline rinsed and reused dialyzers showed considerable amount of decay. C-DAH dialyzers had a larger APD(11.70${\pm}$1.32mmHg/min)compared to CF dialyzers(4.32${\pm}$0.55mmHg/min)(p<0.05). However, there was no observable difference in the UFR between the two dialyzers. Neither APD nor UFR showed any significant increase with an increasing number of reuses for up to more than 20reuses. A substantial number of failures observed in APD(larger than 20mmHe/min)on the reused dialyzers(2 out of 40 CP and S out 26 C-DAK) were attributed to the Possible damage on the fibers. The CF 15-11 HFDs which failed APD test did not show changes in the UFR compared to normal dialyzers indicating that APD is a more sensitive test than UFR test to evaluate the integrity of the fibers. 30527 T00401030527 ^x For quantitative measurement of reflected light from a clinical diagnostic strip, a prototype old reflectance photometer was designed. The strip loader and cassette were made to obtain more accurate reflectance parameters. The strip was illuminated at 45˚c through optical fiber and the intensity of reflected light was determined at rectanguLat angle using a photodiode. The kubelka-munk coefficient and reflection optical density were determined ar four different wavelengths(500,550,570 and 610nm) for blood glucose strip. For higher concentration than 300mg/41 about glucose, a saturation state of abforbance was observed at 500,550 and 570nm. The correlation between glucose concentration and parameters was the best at 610nm. 30535 T00401030535 ^x Radiation-induced fibrosarcoma tumors were grown on the flanks of C3H mice. The mice were divided into two groups. One group was injected with Photofrin II, intravenously (2.5mg/kg body weight). The other group received no Photofrin II. Mice from both groups were irradialed for approximately 15 minutes at 100,300, or 500 mW/cm2 with the argon (488nm/514.5 nm), dye(628nm) and gold vapor (pulsed 628 nm) laser light. A photosensitizer behaved as an added absorber. Under our experimental conditions, the presence of Photolfrin II increased surface temperature by at least 40% and the temperature rise due to 300 mW/cm2 irradiation exceeded values for hyperthermia. Light and temperature distributions with depth were estimated by a computer model. The model demonstrated the influence of wavelength on the thermal process and proved to be a valuable tool to investigate internal temperature rise. 30536 T00401030536 ^x We investigated the structural geometry of thirty-eight Korean femurs. The purpose of this study is to identify major geometrical differences between Korean femurs 3nd others that we believe belong to Caucasians so that we would be able to get insights into the femoral component design that fits Asians including Koreans. We utilized computerized tomography (CT) images of femurs extracted from cadavers. The CT images were transformed into bitmap data by using a film scanner, and then analyzed by using a commercially available software called Image v.1.0 and a Macintosh IIci computer.The resulting data were compared with already published data. The major results show that the geometry of the Korean femurs is significantly different from that of Caucasians: (1) the anteversion angle and the canal flare index are greater by the amount of approximately 8˚ and 0.5, respectively, (2) the shape of the isthmus cross section is more round, and (3) the distance between the teaser trochanter and the proximal border of the isthmus is shelter by about 15 mm. The results suggested that the femoral component suitable for Asians should be different from the currently-used components designed and manufactured mostly by European or American companies. 30537 T00401030537 ^x It is well known that nonlinear propagation characteristics of the wave in the tissue may give very useful information for the medical diagnoisis. In this paper, a new method to detect nonlinear propagation characteristics of the internal vibration in the tissue for the low frequency mechanical vibration by using bispectral analysis is proposed. In the method, low frequency vibration of f0( = 100Hz) is applied on the surface of the object, and the waveform of the internal vibration x (t) is measured from Doppler frequency modulation of silmultaneously transmitted probing ultrasonic waves. Then, the bispectra of the signal x (t) at the frequencies (f0, f0) and (f0, 2f0) are calculated to estimate the nonlinear propagation characteristics as their magnitude ratio, w here since bispectrum is free from the gaussian additive noise we can get the value with high S/N. Basic experimental system is constructed by using 3.0 MHz probing ultrasonic waves and the several experiments are carried out for some phantoms. Results show the superiority of the proposed method to the conventional method using power spectrum and also its usefulness for the tissue characterization. 30541 T00401030541 ^x This paper describes the implementation of a computerized radial pulse diagnosis by aids of a clinical expert. On this base, we composed of the radial pulse diagnosis system in korean traditional medicine. The system composed of a radial pulse wave detection system and a radial pulse diagnosis system. With a detection system, we detected Inyoung and Cheongu radial pulse wave and processed it. Then, we have got the characteristic parameters of radial pulse wave and also quantified that according to the method of Inyoung-Cheongu Comparison Radial Pulse Diagnosis. We defined the jugement standard of radial pulse diagnosis system and then we confirmed the possibility for realization of automatic radial pulse diagnosis in korean traditional medicine. 30545 T00401030545 ^x Microspheres are expected to be applied to biomedical areas such as solid-phase immunoassays, drug delivery systems, immunomagnetic cell separation. To synthesize microspheres for biomedical application, "two stage shot growth method" was developed. The uniformity ratio of synthesized microspheres was always smaller than 1.05. And the surface charge density (or the number of ionizable functional groups) of the microspheres synthesized by "two stage shot growth method" was 6~13 times higher than that of the microspheres synthesized by conventional seeded batch copolymerization. As a previous step for biomedical application, adsorption experiments of bovine albumin on microspheres were carried out under various conditions. The maximum adsorbed amount was obtained in the neighborhood of pH 4.5. Isoelectric point of bovine albumin is pH 5.0, so experimental result shows that it shifted to acid area. The adsorption isotherm was obtained, the plateau region was always reached at 2.Og/L (bulk concentration of bovine albumin).The effect of the kind and the amount of surface functional group was also examined. 30575 T00401030575 ^x A medical image workstation was developed using multimedia technique. The system based on PC-486DX was designed to acquire medical images produced by medical imaging instruments and related audio information, that is, doctors' reporting results. Input information was processed and analyzed, then the results were presented in the form of graph and animation. All the informations of the system were hierarchically related with the image as the apex. Processing and analysis algorithms were implemented so that the diagnostic accuracy could be improved. The diagnosed information can be transferred for patient diagnosis through LAN(local area network). 30592 T00401030592 ^x In the conventional infrared imaging system, complex infrared lens systems are usually used for directing collimated narrow infrared beams into the high speed 2-dimensional optic scanner. In this paper, a simple reflective infrared optic system with a 2-dimensional optic scanner is proposed for the realization of medical infrared thermography system. It has been experimentally proven that the intfrared thermography system composed of the proposed optic system has the temperature resolution of 0.1˚c under the spatial resolution of lmrad, the image matrix size of 256 X 240, and tile imaging time of 4 seconds. 30593 T00401030593 ^x In this paper, MIIS (Medical Image Information System) has been designed and implemented using INGRES RDBMS, which is based on a client/server architecture. The implemented system allows users to register and retrieve patient information, medical images and diagnostic reports. It also provides the function to display these information on workstation windows simultaneously by using the designed menu-driven graphic user interface. The medical image compression/decompression techniques are implemented and integrated into the medical image database system for the efficient data storage and the fast access through the network. 30594 T00401030594 ^x In this paper, computerized BEAM was implemented for the space domain analysis of EEG. Trans-formation from temporal summation to two-dimensional mappings is formed by 4 nearest point inter-polaton method. Methods of representation of BEAM are two. One is dot density method which classify brain electrical potential 9 levels by dot density of gray levels and the other is colour method which classify brain electrical 12 levels by red-green colours. In this BEAM, instantaneous change and average energy distribution over any arbitrary time interval of brain electrical activity could be observed and analyzed easily. In the frequency domain, the distribution of energy spectrum of a special band can easily be distinguished normality and abnormality. 30608 T00401030608 ^x Laboratory information system (LIS) is a key tool to manage laboratory data in clinical pathology. Our department has developed an information system for routine hematology using down-sized computer system. We have used an IBM 486 compatible PC with 16MB main memory, 210 MB hard disk drive, 9 RS-232C port and 24 pin dot printer. The operating system and database management system were SCO UNIX and SCO foxbase, respectively. For program development, we used Xbase language provided by SCO foxbase. The C language was used for interface purpose. To make the system use friendly, pull-down menu was used. The system connected to our hospital information system via application program interface (API), so the information related to patient and request details is automatically transmitted to our computer. Our system interfaced with fwd complete blood count analyzers(Sysmex NE-8000 and Coulter STKS) for unidirectional data tansmission from analyzer to computer. The authors suggests that this system based on down-sized computer could provide a progressive approach to total LIS based on local area network, and the implemented system could serve as a model for other hospital's LIS for routine hematology. 30609 T00401030609 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed a composite that is consisted of calcium phosphate and collagen. To use as the structural matrix of the composite, collagen was purified from human umbilical cord. The obtained collagen was treated by pepsin to remove telopeptides, and finally, the immune-free atelocollagen was produced: The cross linked atelocollagen was highly resistant to the collagenase induced collagenolysis. The cross linked collagen demonstrated an improved tensile strength. 30618 T00401030618 ^x This paper is a study on the design of adptive filter for QRS complex detection. We propose a simple adaptive algorithm to increase capability of noise cancelation in QRS complex detection with two stage adaptive filter. At the first stage, background noise is removed and at the next stage, only spectrum of QRS complex components is passed. Two adaptive filters can afford to keep track of the changes of both noise and QRS complex. Each adaptive filter consists of prediction error filter and FIR filter The impulse response of FIR filter uses coefficients of prediction error filter. The detection rates for 105 and 108 of MIT/BIH data base were 99.3% and 97.4% respectively. 30619 T00401030619 ^x To develop an artificial bone substitute that is gradually degraded and replaced by the regenerated natural bone, the authors designed and produced a composite that is consisted of calcium phosphate and collagen. Human umbilical cord origin pepsin treated type I atelocollagen was used as the structural matrix, by which sintered or non-sintered carbonate apatite was encapsulated to form an inorganic-organic composite. With cross linking atelocollagen by UV ray irradiation, the resistance to both compressive and tensile strength was increased. Collagen degradation by the collagenase induced collagenolysis was also decreased. 30620 T00401030620 ^x We have developed a monoleaflet polymer valve as an inexpensive and viable alternative, especially for short-term use in the ventricular assist device or total artificial heart. The frame and leaflet of the polymer valve were made from polyurethane, To evaluate the hemodynamic performance of the polymer valve a comparative study of flow dynamics past a polymer valve and a St. Jude Medical prosthetic valve under physiological pulsatile flow conditions in vitro was made. Comparisons between the valves were made on the transvalvular pressure drop, regurgitation volume and maximum valve opening area. The polymer valve showed smaller regurgitation volume and transvalvular pressure drop compared to the mechanical valve at higher heart rate. The results showed that the functional characteristics of the polymer valve compared favorably with those of the mechanical valve at higher heart rate. 30621 T00401030621 ^x Explosive evaporative removal process of biological tissue by absorption of a CW laser has been simulated by using gelatin and a multimode Nd:YAG laser. Because the point of maximun temperature of laser-irradiated gelatin exists below the surface due to surface cooling, evaporation at the boiling temperature is made explosively from below the surface. The important parameters of this process are the conduction loss to laser power absorption (defined as the conduction-to-laser power parameter, Nk), the convection heat transfer at the surface to conduction loss (defined as Bi), dimensionless extinction coefficient (defined as Br.), and dimensionless irradiation time (defined as Fo). Dependence of Fo on Nk and Bi has been observed by experiment, and the results have been compared with the numerical results obtained by solving a 2-dimensional conduction equation. Fo and explosion depth (from the surface to the point of maximun temperature) are increased when Nk and Bi are increased.To find out the minimum laser power for explosive evaporative removal process, steady state analysis has been also made. The limit of Nk to induce evaporative removal, which is proportional to the inverse of the laser power, has been obtained. 30622 T00401030622 ^x N1 and N2 gross neural action potentials were measured from the round window of the guinea pig cochlea at the onset of the acoustic stimuli. N1-N2 audiograms were made by means of regulating stimulant intensities in order to produce constant N1-N2 potentials as criteria for different input tone pip frequencies. The lowest threshold was measured with an input tone pip I5 dB SPL in intensity and 12 KHz in frequency when the animal was in normal physiological condition. The procedure of experimental measurements is explained in detail. This experimental approach is very useful for the investigation of the Cochlear function. Both noN1inear and active functions of the Cochlea can be monitored by N1-N2 audiograms. 30623 T00401030623 ^x In electrical impedance tomography(EIT), we use boundary current and voltage measurements toprovide the information about the cross-sectional distribution of electrical impedance or resistivity. One of the major problems in EIT has been the inaccessibility of internal voltage or current data in finding the internal impedance values. We propose a new image reconstruction method using internal current density data measured by NMR. We obtained a two-dimensional current density distribution within a phantom by processing the real and imaginary MR images from a 4.77 NMR machine. We implemented a resistivity mage reconstruction algorithm using the finite element method and sensitivity matrix. We presented computer simulation results of the mage reconstruction algorithm and furture direction of the research. 30624 T00401030624 ^x A new method of digital image analysis technique for discrimination of cancer cell was presented in this paper. The object image was the Thyroid eland cells image that was diagnosed as normal and abnormal (two types of abnormal: follicular neoplastic cell, and papillary neoplastic cell), respectively. By using the proposed region segmentation algorithm, the cells were segmented into nucleus. The 16 feature parameters were used to calculate the features of each nucleus. A9 a consequence of using dominant feature parameters method proposed in this paper, discrimination rate of 91.11% was obtained for Thyroid Gland cells. 30625 T00401030625 ^x An electrical stimulator was designed to induce locomotion for paraplegic patients caused by central nervous system injury. Optimal stimulus parameters, which can minimize muscle fatigue and can achieve effective muscle contraction were determined in slow and fast muscles in Sprague-Dawley rats. Stimulus patterns of our stimulator were designed to simulate electromyographic activity monitored during locomotion of normal subjects. Muscle types of the lower extremity were classified according to their mechanical property of contraction, which are slow muscle (msoleus m.) and fast muscle (medial gastrocneminus m., rectus femoris m., vastus lateralis m.). Optimal parameters of electrical stimulation for slow muscles were 20 Hz, 0.2 ms square pulse. For fast muscle, 40 Hz, 0.3 ms square pulse was optimal to produce repeated contraction. Higher stimulus intensity was required when synergistic muscles were stimulated simultaneously than when they were stimulated individually. Electrical stimulation for each muscle was designed to generate bipedal locomotion, so that individual muscles alternate contraction and relaxation to simulate stance and swing phases. Portable electrical stimulator with 16 channels built in microprocessor was constructed and applied to paraplegic patients due to lumbar cord injury. The electrical stimulator restored partially gait function in paraplegic patients. 30626 T00401030626 ^x Two-Dimensional modelling of the Cochlear biomechanics is presented in this paper. The Laplace partial differential equation which represents the fluid mechanics of the Cochlea has been transformed into two-dimensional electrical transmission line. The procedure of this transformation is explained in detail. The comparison between one and two dimensional models is also presented. This electrical modelling of the basilar membrane (BM) is clearly useful for the next approach to the further. Development of active elements which are essential in the producing of the sharp tuning of the BM. This paper shows that two-dimension model is qualitatively better than one-dimensional model both in amplitude and phase responses of the BM displacement. The present model is only for frequency response. However because the model is electrical, the two-dimensional transmission line model can be extended to time response without any difficult. 30627 T00401030627 ^x A method has been proposed for the fully automatic detection of left ventricular endocardial boundary in 2D short axis echocardiogram using geometric model. The procedure has the following three distinct stages. First, the initial center is estimated by the initial center estimation algorithm which is applied to decimated image. Second, the center estimation algorithm is applied to original image and then best-fit elliptic model estimation is processed. Third, best-fit boundary is detected by the cost function which is based on the best-fit elliptic model. The proposed method shows effective result without manual intervention by a human operator. 30628 T00401030628 ^x The intelligent trajectory control method that controls moving direction and average velocity for a prosthetic arm is proposed by pattern recognition and force estimations using EMG signals. Also, we propose the real time trajectory planning method which generates continuous accelleration paths using 3 stage linear filters to minimize the impact to human body induced by arm motions and to reduce the muscle fatigue. We use combination of MLP and fuzzy filter for pattern recognition to estimate the direction of a muscle and Hogan's method for the force estimation. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. The simulation results of proposed prosthetic arm control system using the EMf signals show that the arm is effectively followed the desired trajectory depended on estimated force and direction of muscle movements. 30638 T00401030638 ^x A new neural network architecture for the recognition of patterns from images is proposed, which is partially based on the results of physiological studies. The proposed network is composed of multi-layers and the nerve cells in each layer are connected by spatial filters which approximate receptive fields in optic nerve fields. In the proposed method, patterns recognition for complicated images is carried out using global features as well as local features such as lines and end-points. A new generating method of matched filers representing global features is proposed in this network. 30659 T00401030659 ^x An implementation scheme of the magnetic nerve stimulator using a switching mode power supply is proposed. By using a switching mode power supply rather than a conventional linear power supply for charging high voltage capacitors, the weight and size of the magnetic nerve stimulator can be considerably reduced. Maximum output voltage of the developed magnetic nerve stimulator using the switching mode power supply is 3,000 volts and switching time is about 100 msec. Experimental results or human nerve stimulations using the developed stimulator are presented. 30768 T00401030768 ^x In this paper, we describe the design methodology and specifications of the developed module-based bedside monitors for patient monitoring. The bedside monitor consists of a main unit and module cases with various parameter modules. The main unit includes a 12.1" TFT color LCD, a main CPU board, and peripherals such as a module controller, Ethernet LAN card, video card, rotate/push button controller, etc. The main unit can connect at maximum three module cases each of which can accommodate up to 7 parameter modules. They include the modules for electrocardiograph, respiration, invasive blood pressure, noninvasive blood pressure, temperature, and SpO2 with Plethysmograph.