Duct-Occlud를 이용한 동맥관개존의 비수술적 폐쇄

오만택,오재화,윤향석 圓光大學校 醫科學硏究所 1999 圓光醫科學 Vol.15 No.2

Background: We tried to occlude the duct with retrievable coil device(Duct-Occlud) in 6 children with patent ductus arteriosus(PDA). And, we reviewed the technical aspects and the short-term results. Methods: PDA occlusion with "Duct-Occlud" system was attempted in 6 patients with small to moderate size PDA from January 1999 to November 1999. Mean age of the patients was 6.56 (1.33 to 14)year. After estimation of the size of PDA, retrievable coil device(Duct-Occlud) was inserted through the femoral vein route. The angiocardiography was performed 10 minutes after the procedure. On next day and one week later, the follow-up echocardiogaphy was checked. And then, it repeated at 3 months, 6 months later. The follow-up duration was 5.5(1 to 11) months. Results: The Qp/Qs was 1.44(1.25 to 1.63), Rp/Rs 0.09(0.03 to 0.15), size of pulmonary end 2.73(2.1 to 3.5)㎜, aortic end 4.58(2.8 to 5.5)㎜, length 5.83(3.8 to 8)㎜. The complication of the procedure occurred in one patient by uneventful earlier detatchment. Flow disturbance was not developed. Conclusions: Coil occlusion with the Duct-Occlud system is a safe and effective method for percutaneous closure of small to moderate-size PDAs. Larger numbers of treated patients and longer follow-up period would be necessary to more precisely define the efficacy, and most appropriate indications for this system.

분류와 회귀나무분석에 관한 소고

임용빈,오만숙 한국품질경영학회 2002 품질경영학회지 Vol.30 No.1

대용량 자료를 다루는 데이터 마이닝에서 자료분석의 주요 도구인 분류나무와 희귀나무는 모형이 나무구조의 그림으로 시각적으로 표현되어서, 모형의 해석이 쉽다는 이점을 가지고 있다. 자료들의 약간의 변화 또는 흔들음(perturbation)이 나무구조나 예측치들의 커다란 변화를 초래할 수 있다는 점에서 나무예측치들이 불안정하다는 사실은 잘 알려져 있다. 불안정성을 개선하고 예측치의 정밀성을 높이기 위한 해결책의 하나는 다중 나무예측치를 사용하는 것이다. 이 때 치루어야할 대가는 예측치가 더 이상 나무구조로 표현되지 않아서 해석의 용이성을 잃는 것이다. 항암제나 에이즈 치료를 위한 백식개발등의 연구 개발의 처음 단계에서의 목표는 질병치료에 도움이 될 생물학적으로 효능있는 화합물 (potent molecules)들을 합성되지 않은 수십만 개의 화합물들 중에서 찾는 것이다. 데이터 베이스에 구축된 모든 화합물들의 합성과 검사에는 많은 비용과 시간이 소요되어 현실적으로 불가능하다. 따라서 소규모 양의 합성과 검사로 얻어진 자료를 가지고 희귀나무를 이용하여 반응치를 예측하여 검사되지 않은 화합물 중에서 효능이 있으리라 기대되는 화합물들을 선별하는 과정을 반복하는 축차적인 전략은 실용적인 가치가 매우 높은 체계적인 방법이다. The analysis of large data sets with hundreds of thousands observations and thousands of independent variables is a formidable computational task. A less parametric method, capable of identifying important independent variables and their interactions, is a tree structured approach to regression and classification. It gives a graphical and often illuminating way of looking at data in classification and regression problems. In this paper we have reviewed and summarized the methodology used to construct a tree, multiple trees and the sequential strategy for identifying active compounds in large chemical databases.

DOC의 K-7 Mode에 의한 배기가스 저감에 관한 연구

한영출,백두성,오용석,박만재,박귀열,류규현 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.3

With the significant growth of the number of vehicles, environmental problems is raised. NOx, SOx, and PM emissions in diesel powered vehicles are larger than that in gasoline, because the development of pollutants reduction techniques has no: been yet achieved. So it is need to develop after-treatment or to convert into alternative fuel to satisfy emission regula-tion. Among the after-treatment systems to reduce the diesel emissions, studies with diesel oxidation catalyst(DOC) are done greatly. In this study using DOC, reduction efficiency with the change of temperature and catalyst loading was calculated through measurements of CO, HC, PM, and SOx.

중환자에서 동맥혈 가스분석 횟수와 그로인한 실혈량에 대한 연구

이석열,전철우,정영수,오희숙,마분란,이정미,정혜영,이만복,이길노 순천향의학연구소;Soonchunhyang Medical Research Institute 2000 Journal of Soonchunhyang Medical Science Vol.6 No.1

Background : Arterial blood gas analysis is the most comon exam in intensive care unit. In this study, the frequency of blood gas analysis and the amount of blood loss after Blood Gas Analysis in Intensive Care Unit were observed. Methods : From November 1999 to February 2000, 115 patients admitted to intensive care unit at Soonchunhyang university Kumi hospital were studied prospectively for the frequency of blood gas analysis and the amount of blood loss after blood gas analysis in Intensive Care Unit. Results : The mean value of frequency of blood gas analysis was 6.41±6.49 and the mean value of amount of blood loss after blood gas analysis was 0.78ml. This was lower than that of other foreign reports. The patients with ventilator therapy above 24 hours showed higher frequency of blood gas analysis than that of not applied ventilator patients. Pulse oxymetry was applied to all patients and the frequency of blood gas analysis was decreased due to the use of strict pulse oxymetry. Conclusion : Doctors and nurses in intensive care unit keep in mind that adequate blood sampling is needed for the decrease of blood loss. Education and protocol for the decrease of blood loss after arterial blood gas analysis may be necessary.

우수 사과酒酵母의 分離와 利用에 關한 硏究

朴允仲,金燦祚,李錫健,吳萬鎭,孫天培 충남대학교 농업과학연구소 1978 農業技術硏究報告 Vol.5 No.1

Extensive selection works on wild yeasts of fruits were carried cut to obtain strains which are applicable to apple wine making. Among the total number of 1,358 yeast strains which were isolated from various fruit samples collected from the vicinity of Daejeon and other regions of Korea, the strains SH-49, SH-129 and SH-338 were found to be useful. Then experiments on their morphological and physiological characteristics, and on the aspects of practical use in apple wine making were proceeded. The results obtained were as follows: 1. The strains SH-49 and SH-129, particularly SH-49, were appeared to have good fermentation ability, tolerance to sulfur dioxide and to produce fine quality of apple wine. 2. Apple wines made by using the strain, SH-49 and SH-129 contained less amount of total acids than those by other strains. 3. Apple wines of SH-49 and SH-129 were clarified rapidly during the primary fermentation period, and their absorbancy at 430 nm after 45 days of storage were approximately half of others. 4. Apple wine of SH-338 contained higher amount of residual sugar and its quality was superior to others. It is considered that this strain could be used in the production of apple wine of a characteristic quality. 5. The strains SH-49 and SH-338 were identified as a Saccharomyces cerevisiae according to Taxanomic Study of Yeasts by Lodder, however, classification of SH-129 was suspended for further study.

터보 차져와 인터쿨러를 장착한 디젤기관의 시뮬레이션 연구

한영출,백두성,류규현,오용석,박만재 韓國工作機械學會 2000 한국생산제조학회지 Vol.9 No.4

Studies on the turbocharger itself or various aspects generated from turbocharged engine have been made. However, only a few researches have been made on the performance for the natural aspirated engine equipped with the turbocharger and the intercooler. In this study, the performance prediction program based on turbocharger theory is developed for simu-lation which may reduce the cost and the trial-and-error time. The program is verified with the experimental results for 11,000cc diesel engine with the turbocharger and the intercooler. Also, various factors which are invisible in experiment are predicted using this program.

Efficiency and Robustness of Fully Adaptive Simulated Maximum Likelihood Method

Oh, Man-Suk,Kim, Dai-Gyoung The Korean Statistical Society 2009 Communications for statistical applications and me Vol.16 No.3

When a part of data is unobserved the marginal likelihood of parameters given the observed data often involves analytically intractable high dimensional integral and hence it is hard to find the maximum likelihood estimate of the parameters. Simulated maximum likelihood(SML) method which estimates the marginal likelihood via Monte Carlo importance sampling and optimize the estimated marginal likelihood has been used in many applications. A key issue in SML is to find a good proposal density from which Monte Carlo samples are generated. The optimal proposal density is the conditional density of the unobserved data given the parameters and the observed data, and attempts have been given to find a good approximation to the optimal proposal density. Algorithms which adaptively improve the proposal density have been widely used due to its simplicity and efficiency. In this paper, we describe a fully adaptive algorithm which has been used by some practitioners but has not been well recognized in statistical literature, and evaluate its estimation performance and robustness via a simulation study. The simulation study shows a great improvement in the order of magnitudes in the mean squared error, compared to non-adaptive or partially adaptive SML methods. Also, it is shown that the fully adaptive SML is robust in a sense that it is insensitive to the starting points in the optimization routine.

Bayesian Analysis of Randomized Response Models : A Gibbs Sampling Approach

Oh, Man-Suk The Korean Statistical Society 1994 Journal of the Korean Statistical Society Vol.23 No.2

In Bayesian analysis of randomized response models, the likelihood function does not combine tractably with typical priors for the parameters of interest, causing computational difficulties in posterior analysis of the parameters of interest. In this article, the difficulties are solved by introducing appropriate latent variables to the model and using the Gibbs sampling algorithm.

Bayesian Parameter :Estimation and Variable Selection in Random Effects Generalised Linear Models for Count Data

Oh, Man-Suk,Park, Tae-Sung The Korean Statistical Society 2002 Journal of the Korean Statistical Society Vol.31 No.1

Random effects generalised linear models are useful for analysing clustered count data in which responses are usually correlated. We propose a Bayesian approach to parameter estimation and variable selection in random effects generalised linear models for count data. A simple Gibbs sampling algorithm for parameter estimation is presented and a simple and efficient variable selection is done by using the Gibbs outputs. An illustrative example is provided.

PERFORMANCE EVALUATION VIA MONTE CARLO IMPORTANCE SAMPLING IN SINGLE USER DIGITAL COMMUNICATION SYSTEMS

Oh Man-Suk The Korean Statistical Society 2006 Journal of the Korean Statistical Society Vol.35 No.2

This research proposes an efficient Monte Carlo algorithm for computing error probability in high performance digital communication st stems. It characterizes special features of the problem and suggests an importance sampling algorithm specially designed to handle the problem. It uses a shifted exponential density as the importance sampling density, and shows an adaptive way of choosing the rate and the origin of the shifted exponential density. Instead of equal allocation, an intelligent allocation of the samples is proposed so that more samples are allocated to more important part of the error probability. The algorithm uses the nested feature of the error space and avoids redundancy in estimating the probability. The algorithm is applied to an example data set and shows a great improvement in accuracy of the error probability estimation.