MHD WAVE ENERGY FLUXES GENERATED FROM CONVECTION ZONES OF LATE TYPE STARS

Moon, Yong-Jae,Yun, Hong-Sik The Korean Astronomical Society 1991 Journal of The Korean Astronomical Society Vol.24 No.2

An attempt has been made to examine the characteristics of acoustic and MHD waves generated in stellar convection zones($4000\;K\;{\leq}\;T_{eff}\;{\leq}\;7000\;K$, $3\;{\leq}\;\log\;g\;{\leq}\;4.5$). With the use of wave generation theories formulated for acoustic waves by Stein (1967), for MHD body waves by Musielak and Rosner (1987, 1988) and for MHD tube waves by Musielak et al.(l989a, 1989b), the energy fluxes are calculated and their dependence on effective temperature, surface gravity and megnetic field strength are analyzed by optimization techniques. In computing magneto-convection models, the effect of magnetic fields on the efficiency of convection has been taking into account by extrapolating it from Yun's sunspot models(1968; 1970). Our study shows that acoustic wave fluxes are dominant in F and G stars, while the MHD waves dominant in K and M stars, and that the MHD wave fluxes vary as $T_{eff}^4{\sim}T_{eff}^7$ in contrast to the acoustic fluxes, as $T_{eff}^{10}$. The gravity dependence, on the other hand, is found to be relatively weak; the acoustic wave fluxes ${\varpropto}\;g^{-0.5}$, the longitudinal tube wave fluxes ${\varpropto}\;g^{0.3}$ and the transverse tube wave fluxes ${\varpropto}\;g^{0.3}$. In the case of the MHD body waves their gravity dependence is found to be nearly negligible. Finally we assesed the computed energy fluxes by comparing them with the observed fluxes $F_{ob}$ of CIV(${\lambda}1549$) lines and soft X-rays for selected main sequence stars. When we scaled the corrected wave fluxes down to $F_{ob}$, it is found that these slopes are almost in line with each other.

원형도파관과 구형도파관간의 T-접합 분기회로 해석

문성익,허광삼,김윤영,양두영 제주대학교 산업기술연구소 2000 尖端技術硏究所論文集 Vol.11 No.1

In this paper, the T-junction branch network of the orthomode transducer is analyzed. The T-junction blanch network consists of the cylindrical common waveguide and the rectangular sub-waveguide. Using the vector potential of each region, the hybrid mode is considered. Based on the derived electromagnetic components, scattering parameters of the T-junction branch network are calculated. The cylindrical waveguide size and the rectangular waveguide size are WR62 and WC55. In order to analyze the discontinuity of the T-junction branch network, high order mode of the branch region is considered the 15th. From the results, the transmission coefficient. S31 and S21 show -3dB, the reflection coefficient, S11 and S33 are -10dB, -8dB in the range of 13.3GMz∼16GHz.

노인외상환자의 예후 인자

문철규,전정민,최성혁,문준동,이성우,홍윤식 大韓應急醫學會 1999 대한응급의학회지 Vol.10 No.2

Background: It has been documented that certain prognostic factors may affect the outcomes of the old aged victims by trauma. Considering that trauma is the sixth most common cause of death in people over the age of 65 years and there is a rapid growth of elderly population, it is paramount to understand the prognostic factors when dealing with geriatric trauma patients. Hypothesis and Goals: It can be hypothesized that the prognostic factors should be determined independently between populations being consisted of different races, countries, socio-economic states, cultures, or so on. Thus, the study was designed to evaluate the factors affecting the outcomes of elderly Korean trauma patients. Methods: One hundred forty six patients aged over 65 years were retrospectively reviewed, who visited the Emergency Center of Korea University from January, 1997 to June, 1998. Of 146 patients, 7 were excluded due to discharge against advice or transfer to the other hospitals. Parameters analyzed were age, sex, mechanism of injuries, body region injured, Injury Severity Score (ISS), previous medical illness, hospital morbidity, duration of hospital stay, and cost. Each patient was classified into improved or not-improved group depending on the outcomes, and young-old or old-old group depending on the age. The factors affecting the hospital stay in improved patients were analyzed in the parameters of previous medical illness, hospital morbidity, multiple injuries, ISS, and age. All statistical tests were conducted with two-tailed levels of 0.05. Results: Of 139 patients, the mean age was 74±7.1 years, mean ISS 9.3±7.26, mean hospital stay 27±27.1 days. Most commonly injured body region was the extremities due to fall from a level surface. Rate of previous illness showed 0.94 medical diseases per person and were aggravated after trauma in 39 patients (60.9%). Hospital morbidity rate was 0.46 incidents per person. There were no differences in age and duration of hospital stay between the improved and the not-improved group. Substantial differences were noted in affected body region, incidence of previous illness, and hospital morbidity between the groups (p=NS). Not-improved group had higher ISS(p<0.05). ISS, previous illness and hospital morbidity affected the duration of hospital stay in the improved group. Hospital stay was 40±25.1 days in patients with ISS over 6 while 6±8.6 days in those with ISS 5(p<0.05). Hospital stay in the improved was 26±26.9 days while 31±24.8 days in the improved old-old group (p=NS). Hospital stay in the young-old minor trauma (ISS5) patients with previous illness and hospital morbidity was 26±10.1 days while 4±7.3 days in those without previous illness and hospital morbidity (p<0.05). Conclusion: Previous medical illness and hospital morbidity, not age, are predictive of outcomes of geriatric trauma patients with respect to hospital stay. As most of the hospital morbidity was a trauma-induced aggravation of previous medical illness and hospital morbidity contributing poor outcomes can be potentially avoidable, routine aggressive care for the geriatric trauma patients with previous medical illnesses is needed.

위암 환자에서 위절제술후 나타나는 담도확장의 임상적 의의: 추적 CT 소견을 중심으로

윤구섭,백승연,이문규,김영환,오용호 울산대학교 의과대학 1993 울산의대학술지 Vol.2 No.1

A retrospective review of consecutive 35 patients'pre and post operative abdominal computed tomography was performed to determine frequency and degree of bile duct dilatation following Billroth Ⅱ operation for stomach cancer and it's clinical significance. Degree of intrahepatic biliary dilatation was classified as mild, moderate, marked according to the extension into central, middle and peripheral zone of liver, respectively. Three specialists on the abdominal image participated in analysis of those findings without prior information of the patients. Intrahepatic biliary dilatation was seen in 22 patients(63%) analysed by at least one radiologist, in 13 patients(37%) by at least two radiologists. Bile duct dilatation on CT was common finding and not necessarily meant tumor recurrence. Vagotomy and afferent loop resulted form Billroth Ⅱ were one of possible causes of bile duct dilatation. This study showed in the cases of bile duct dilatation without clinical and other radiological evidence of recurrence, no further study are needed and only enough to follow up study.

부산지역 대기질에 대한 대기 오염 지수(PSI)의 적용

문윤섭,장난심,김영주 부산대학교 환경문제연구소 1997 環境硏究報 Vol.15 No.1

The Pollutant Standards Index (PSI) was chosen as an environmental indicator. The PSI is a composite indicator computed from ambient levels of SO2 , TSP,O3 , NO2 , and CO. The daily PSI value is determined by the pollutant having the highest reading for that day. The index numbers are on a scale of zero to 500, the most important number on the scale is 100, which corresponds to the EPA - set National Ambient Air Quality Standars (NAAQS). Scores higher than 100 are considered to be unhealthful. Air quality of Pusan was evaluated by Pollutant Standards Index, which was proposed by Federal Register of the United States. The daily data of pollutants (SO2 , TSP, O3 , NO2 , CO) in 6 air pollutant monitoring sites were used for evaluation. According to the frequencies (day/day %), most parts were still under unhealthful condition. But, this result was why too many data of the high O3 concentration value in summer was missing. As the result, PSI method seems very useful to evaluate air quality, if the air quality pollutant data has no missing one, but it would be necessary to reform in consideration of environment standard of Pusan, in the case of applicating PSI in Pusan, Korea.

차분방정식의 해의 형태에 관한 연구

문경천,고윤희 濟州大學校 師範大學 科學敎育硏究所 1997 科學敎育 Vol.14 No.-

In this thesis, we obtain sufficient conditions on the difference equation x(n + 1) = f { x ( n)} to ensure the existence and the asymptotic stability of the constant solution. Also, we present examples to apply the above results.

중증 외상환자에서 염기 결핍수치의 유용성

문준동,김수진,문철규,최성혁,전정민,이성우,홍윤식 대한응급의학회 2001 대한응급의학회지 Vol.12 No.3

Background: This study's objective was to determine the prognostic value of the base deficit measured in the emergency department(ED) and to determine whether base deficit can provide information not provided by advanced injury scoring system. Methods: This study was a retrospective analysis of data collected for two years. Thirty-two severe trauma patients who were admitted to the Emergency Department of Korea University Hospital were included in this study. The patients were divided into two groups: the normal base deficit group(-3 mmol/L to 3 mmol/L) and the elevated base deficit group(>3 mmol/L). The base-deficit value, age, sex, head injury, organ failure rate, and survival were considered, and the also Revised Trauma Score(RTS), Acute Physiology And Chronic Health Evaluation(APACHE II), and Injury Severity Score(ISS) were measured. Result: The elevated base-deficit group showed a lower survival rate and a higher organ failure rate compared to the normal base deficit group. Logistic Regression showed a strong association between base deficit and mortality rate. Among the previous injury scoring Systems(RTS, APACHE II, ISS), base deficit had the strongest correlation with RTS. By using base deficit value and the RTS together, we obtained a higher positive predictive value than that obtained by using base deficit or RTS alone. Conclusion: The admission value of the base deficit in the ED is a useful tool in predicting the outcome in severe trauma patients, and it can be an adjunct to previous injury scoring systems. As an advanced injury scoring System is developed in the future, the base deficit may have some significant role.

다운증아의 단기기억(시각 회상기억과 청각 재인기억)에 관한 연구

윤문숙 경상대학교 사회과학연구소 2005 사회과학연구 Vol.23 No.-

The purpose of this study is to determine if there is significant differences between Down Syndrome children and normal children in visual recall memory and auditory recognition memory. 20 Down Syndrome children and 20 normal children were selected foir this study. In visual recall memory, a number was presented to subjects for about 1 second visually and then subjects were required to recall it. Group(2) design was used. The data was analyzed by T-test. The result was as follows: There was no difference between Down Syndrome children and normal children in visual recall memory. In auditory recognition memory, a number was presented to subjects for about 1 second auditorily and then subjects were required to select it among three items. Group(2) design was used. The data was analyzed by T-test. The result was as follows: There was no difference between Down Syndrome children and normal children in auditory recognition memory.

다운증아의 촉각 변별능력 특성에 관한 연구

윤문숙 경상대학교 사회과학연구소 2002 사회과학연구 Vol.20 No.1

The purpose of this study is to determine if there are significant differences among Down's Syndrome children, Non-Down's Syndrome retarded and normal children in tactual-tactual discrimination skills. 30 Down's Syndrome children, 30 Non-Down's Syndrome retarded, and 30 normal children whose MA is 4-5 years old, and 30 Down's Syndrome children, 30 Non-Down's Syndrome retarded, and 30 normal children whose MA is 7-8 years old were selected for the experiments. At a three forced-choice simultaneous paradigm, subjects were required to explore a standard shape and then select a matching shape, Group (3) x MA(2) design was used. These data were analyzed by ANOVA. the results were as follows: the main effect of the group and the main effect of MA were found significant. All of these data were analyzed by Scheffe-test. The results were as follows: Down's Syndrome children were significantly inferior to Non-Down's Syndrome retarded and normal children tactual-tactual discrimination skills. At the preoperational stage, Down's Syndrome children were the same as all the Down's Syndrome children. At the concrete operational stage, Down's Syndrome children were significantly inferior to normal children in tactual-tactual discrimination skills.

원형도파관과 구형도파관간의 T-접합 분기회로 해석

문성익,김윤영,허광삼,양두영 濟州大學校 産業技術硏究所 2000 산업기술연구소논문집 Vol.11 No.1

In this paper, the T-junction branch network of the orthomode transducer is analyzed. The T-junction branch network consists of the cylindrical comnion waveguide and the rectangular sub-waveguide. Using the vector potential of each region. the hybrid mode is considered Based on the derived electromagnetic components. scattering parameters of the T-junction branch network are calculated. The cylindrical waveguide size and the rectangular waveguide size are WR62 and WC55. In order to analyze the discontinuity of the T-junction branch network. high order mode of the branch region is considered the 15th. From the results. the transmission coefficient. S_(31) and S_(21) show -3dB. the reflection coefficient. S_(11) and S_(33) are -10dB. -8dB in the range of 13.3GHz-16GHz.