Treatment of Radioactive Liquid Waste by the Forced-AirCirculation System

Tae-κuk Kim,IL Sik Kang,Jong-Sik Shon,Young-Gerl Ryu,Won-Hyuk Jang,Sang-Min Bae,Young-Yong Ji,Dae-Seok Hong,Kyung-Kil Kwak 한국방사성폐기물학회 2011 한국방사성폐기물학회 학술논문요약집 Vol.9 No.2

혈중 및 호기 일산화탄소를 이용한 일산화탄소 헤모글로빈 농도간의 관련성 연구

김형수,박태혁,손지언,정갑열,김정만,김준연 동아대학교 2001 大學院論文集 Vol.26 No.-

This study was conducted to find a correlation between blood COHb and calculated COHb with expiratory air and related variables such as occupational and smoking factors. Author selected 69 healthy workers in 8 workplaces suspected CO exposure. Basic informations were collected by self-reported questionnaire and medical history taking. Author measured Indirect COHb concentration with expiratory air using Micro II-Smokerlyzer and blood COHb concentration using Oxymeter. The results of the study were summarized as follows : 1. In the smoker, mean blood COHb and calculated COHb with expiratory air were 2.21±0.98% and 2.27±0.97 %, and there was not a statistically significant difference. In the non-smoker, mean blood COHb and calculated COHb with expiratory air were 0.42±0.43 % and 0,65±0.30 %, and there was also not a statistically significant difference. 2. There were positive correlations between blood COHb and calculated COHb with expiratory air in both the smoker (r=0.91, p=0.0001) and non-smoker (r=0.73, p=0.0001). 3. In the smoker, the factors affected COHb were total smoking index (Pack × years) and passed time after the last smoking. 4. In the nonsmoker, the parking and driving groups had higher COHb concentration than others (p<0.05). In conclusion, there was no significant difference between indirect COHb concentration with expiratory air using Smokerlyzer and blood COHb concentration and there was a highly significant correlation between indirect and blood COHb concentrations. Therefore indirect COHb concentration with expiratory air is a useful screening method for CO exposure. Author suggest the resection of smoking during at least 90 minutes before measuring COHb concentration in order to exclude smoking effects.

원-달러 선물시장의 헤지 효율성 비교

김태혁,박종해 釜山 大學校 經營 經濟 硏究所 2003 經營 經濟 硏究 Vol.22 No.1

이 연구는 기존의 연구에서 제시된 다양한 헤지 모델들을 이용하여 우리나라 원-달러 선물환율의 변동성을 관리하는데 필요한 원-달러 선물의 최적 헤지 비율을 추정하고 헤지 효율성을 서로 비교한다. 원-달러 현물환율과 선물환율을 기초자료로, 최적의 헤지 비율은 OLS 회귀모델, 이변량 벡터 자기회귀모델(BVAR), 오차수정모형(ECM) 그리고 다변량 대각 Vec GARCH 모델을 이용하여 계산한다. 헤지 효율성은 1일과 5거래일의 예측기간에 있어서 사후적 및 사전적 위험감소효과 및 위험-수익률 교환관계의 관점에서 검증된다. 일반적으로 GARCH 시간 가변 헤지 비율은 장기간의 헤지에 있어서 포트폴리오의 위험을 감소시키는데 가장 적합한 수단으로 알려져 있다. 그러나 우리나라 원-달러 선물시장의 경우 시간 가변 헤지방법은 시간불변 헤지방법에 비하여 헤지효율성 측면이나 헤지포트폴리오의 수익-위험 교환관계의 관점에서 더 나은 방법으로 받아들일 수 없는 실증결과를 보였다.

Phytol과 들미나리추출물이 Sarcoma 180마우스의 T Subset에 미치는 효과

류태형,박건영,장명웅,이숙희,선우양일,김광혁 東亞大學校附設基礎科學硏究所 1993 基礎科學硏究論文集 Vol.10 No.1

본 연구는 녹황색채소류에서 추출되어 항암효과를 나타내는 활성물질로 보고 되어 있는 phytol과 들미나리추출물을 sarcoma 180마우스에 주사한 후 적출한 비장세포내 T 임프구와 T subset, 그리고 asialo ?? 세포를 정량하여 다음과 같은 결과를 얻었다. 1) 종양 마우스에 phytol을 투여하였을 때 비장세포내의 T cell과 T-subset은 종양세포이식에 의하여 상승된 치를 더욱 증가시켰다. 그러나 들미나리추출물의 경우는 대동소이하였다. 2) Asialo ?? 세포는 종양마우스에 phytol이나 들미나리추출물을 주사하였을 때 모두 상승하였으며 정상마우스에 phytol을 투여하였을 때도 대조군에 비하여 상승했지만 들미나리추출물을 작용시켰을 때는 저하되었다. 3) ??/?? 세포비는 종양마우스에 phytol을 주사하였을 때 감소를 보였지만 정상 마우스에 투여하였을 때는 더욱 크게 낮아졌다. 그러나 들미나리추출물을 정상마우스에 투여하였을때는 크게 감소하던 것이 종양마우스에 적요 시켰을때는 증가현상을 보였다. 이상의 결과로 미루어 볼 때 phytol이나 들미나리추출물은 종양마우스에서 작용자세포인 자연살해세포(natural killer cell)의 활성인자로서 작용할 가능성이 높을 것으로 사료된다. Several studies have shown that phytol isolated from perilla leaf and small water dropwort(Oenanthe javanica(BL)D.C, wild type)extract reveal antitumor activities. In the present study we investigated the effect of phytol and the small water dropwort extract on the T subset in the sarcoma 180-transplanted mice in order to elucidate the immunological mechanism of antitumor activity of these substances. The results obtained from the experiment were as follows : When phytol was injected into the sarcoma-180 transplanted mice(control), the levels of T cell and T subset by inoculation of the tumor cells were enhanced, but that of T cells in case of small water dropwort extract was similar to the control. Asialo ?? cells were increased when phytol or small water dropwort extract was injected into tumor-transplanted mice. In normal mice the number of asialo ?? cells increased with phytol injection and decreased with small water dropwort extract injection. ??/?? cell ratios were decreased when phytol was injected into tumor-transplanted mice, but increased in case of small water dropwort extract injection. In normal mice the ratios showed large decreases with phytol or small water dropwort extract injection. These results indicate that phytol or small water dropwort extract can activate the proliferation of natural killer cells that are effector cells in tumor-bearing mice.

여재 특성에 따른 생물막여과 공법의 처리특성에 관한 연구

강용태,양희천,송근관,권혁원 동아대학교 건설기술연구소 1999 硏究報告 Vol.23 No.2

In the biofilteration process, the removal of turbidity, color, KMnO₄consumpion, NH₄^(+)-N and UV254 reached 98%, 95%, 70%, 85%, 79% respectively. The stable removal efficiency was obtained by the direct filteration after coagulant dosage, though the influent was muddy and highly polluted. The exhausted GAC was used as the media of biofilter, which obtained stable removal efficiency compared with the other medias such as GAC, ZEOCARBON. Effluent of sorptived THMs was not found after 45 days during filter run time. And the case of dual media filteration was prior to single media filteration in the headloss development and quality of effluent. In the case of the ozone dosage rate was determined the color of biofilteration in the AAWTS system. 1㎎/L ozone dosage was proper when the color was below 8 unit.

뇌 동맥류성 지주막하출혈의 합병증

이제혁,김태선 대한뇌혈관학회 2001 대한뇌혈관학회지 Vol.3 No.1

클로르헥시딘 바니쉬의 적용이 교정용 브라켓의 전단접착강도에 미치는 영향

임동혁,김태우,장영일,남동석,양원식,백승학 대한치과교정학회 2000 대한치과교정학회지 Vol.30 No.2

본 연구의 목적은 클로르헥시딘 처리가 교정용 브라켓의 전단접착강도와 탈락 양상에 미치는 영향을 비교하는 것이다. 실험군으로 4주간 4회의 클로르헥시딘 바니쉬를 도포한 22개의 사람 소구치를 선택하였고, 대조군으로 아무 처리도 하지 않은 22개의 사람 소구치를 선택하였다. 모든 치아는 37%의 phosphoric acid gel로 부식시키고 교정용 브라켓을 같은 조건으로 부착시켰다. 전단접착강도의 측정을 위해 Instron universal testing machine(model 4466)을 이용하였고, 법랑질과 브라켓 표면은 SEM으로 관찰하였다. 결과의 분석은 t-test를 이용하였으며 결과는 다음과 같다. 1.클로르헥시딘의 법랑질 처리는 전단접착강도에 영향을 미치지 않았다. 2.클로르헥시딘으로 법랑질을 처리한 경우와 그렇지 않는 경우에 브라켓 탈락 양상에 차이가 없었다. 따라서, 클로르헥시딘으로 법랑질을 처리하여도 브라켓 접착에 유해한 작용이 없었고, 따라서 임상사용에 적합하다고 생각된다. The purpose of this study was to determine whether the application of chlorhexidine varnish affects the shear bond strength and failure pattern of orthodontic brackets or not. The experimental group consisted of 22 human premolars which extracted after chlorhexidine vanish application(4 times for 1 week interval) in vivo, and the control group consisted of 22 human premolars which extracted without any pre-treatment. After all teeth were etched with 37% phosphoric acid gel, metal orthodontic brackets (Q-3002, RMO, USA) were bonded to each tooth using auto-polymerizing orthodontic resin (Ortho-One, Bisco, USA) with the same bonding procedure. The shear bond strength was measured with Instron universal testing machine (model 4466, Instron Ltd., England), and the failure pattern of each bracket was examined with Scanning Electron Microscope (SM 840A, JEOL, Japan). The data were analysed statistically with t-test. The results were as follows : 1.Application of chlorhexidine varnish had no significant effect on the shear bond strength of the orthodontic bracket. 2.There was no significant difference in the failure pattern of orthodontic bracket between the experimental group and the control group.

급성 심근경색증을 동반한 혈전성 혈소판 감소성 자반증 1예

이태희,김진혁,김완중,박지영,강흥선,조정휘,김권삼,송정상,배종화 대한순환기학회 2003 Korean Circulation Journal Vol.33 No.11

한국 주식시장 효율성 검증을 위한 초과수익률 측정방법론에 관한 연구

김태혁 釜山大學校 商科大學 1997 釜山商大論集 Vol.68 No.-

This paper is mainly concerned with identifying statistical and practical problems relating to the test of Korean stock market efficiency. Most of empirical tests for market efficiency have been done by measuring abnormal stock returns and their statistical significancy. In order to preceeded the test, researchers follow four stages, that is, determining the minimum time unit of investment, selecting the market return, measuring average returns of sample portfolios, and measuring abnormal performance of the portfolios. In the first stage, the researcher should determine the minimum time unit of stock returns - daily, weekly, monthly, or annual returns. Next, he or she needs to decide whether the weighted market index or the equally weighted market index should be used for measuring the market performance. In the third stage, the researcher can use one of four alternative methodologies for the measurement of the abnormal return of the individual security -mean adjusted return, market adjusted return, risk adjusted return, and industry adjusted return. In the final stage, the researcher should decide how to measure the portfolio abnormal returns realized during various test periods. Roll(1983) reports that following four methods can be used for the measurement of portfolio average (abnormal) returns - cumulative return, arithmetic return, revalanced return, and buy and holden return. But Brown and Warner (198), Roll (1981,1983), Fama (1991), and Conrad and Kaul (1993) maintain that among four alternative abnormal performance measures, the buy and holden abnormal return is the most desirable measure both in economic and statistical sense. They also criticize that cumulative abnormal return is a biased and unrealistic measure of portfolio abnormal performance. This paper reviews the methodologies employed in the event studies on Korean market efficiency and finds that most of studies use cumulative abnormal returns which have the most serious statistical and economic problem. In order to recommend the researcher to use the buy and holden abnormal return instead of cumulative abnormal return, this paper attempts to show how the estimated portfolio excess returns differ depending on alternative performance measurements based on the monthly stock returns and market return of the Korean Stock Market during the 1980-1995 period. Therefore, This research contributes to employ better methodology for the future event study on the Korean Stock Market.

우리나라 株式市場에서의 月中效果와 그 原因에 대한 實證的 硏究

김태혁,이정곤 釜山大學校 商科大學 1995 釜山商大論集 Vol.66 No.-

The purpose of this study is to examine the existence of monthly effects and to discover the causes of monthly effects in the Korean Stock Market. According to the prior empirical studies, the existence of monthly effect varies largely depending on the selection of trading month. The results from this study show the monthly effect, confirmed by the fact that the mean cumulative return of the last half of calendar month exceeds that of the first half of calendar month, significantly exists in the Korean Stock Market opposed to the U.S. Stock Market. This study also found that the monthly effect is affected by corporate disclosure and is heavily influenced by the turn-of-the month effect. The empirical results found are as follows; First, by selecting calendar month as trading month, the monthly effect appears in the Korean Stock Market. Particularly, the fact that cumulative return for the last half exceeds that for the first half totally differs from the prior empirical results including Ariel's study. Second, January effect may affect the monthly effect, but large stocks show stronger evidence of the monthly effect even after excluding the returns realized during January. That is, large stocks have experienced higher month-end returns for the rest of eleven months Third, the weekend effect does not affect the monthly effect, but timely corporate disclosure appears to major causes of the monthly effect. Finally, this study suggests the optimal investment strategy based on utilizing the monthly effect. According to the cumulative returns for nine(six) trading days, the maximum return can be realized by holding stocks from the last five(four) trading days of the particular trading month to the first four(two) trading days of the next trading month. Therefore, it is recognized that the calendar trading effect are heavily influenced by the turn of the month effect.