Magnetic Resonance Imaging: Historical Overview, Technical Developments, and Clinical Applications

Jahng, Geon-Ho,Park, Soonchan,Ryu, Chang-Woo,Cho, Zang-Hee Korean Society of Medical Physics 2020 의학물리 Vol.31 No.3

The authors congratulate the cerebrations for the 30 years of the Korean Society of Medical Physics (http://www.ksmp.or.kr/). The paper is published to recognize the anniversary. Geon-Ho Jahng invited Professor Z. H. Cho to join to submit this manuscript because he has been one of the leaders in the field of magnetic resonance imaging (MRI) during the last 40 years. In this review, we describe the development and clinical histories of MRI internationally and domestically. We also discuss diffusion and perfusion MRI, molecular imaging using MRI and MR spectroscopy (MRS), and the hybrid systems, such as positron emission tomography-MRI (PET-MRI), MR-guided focused ultrasound surgery (MRgFUS), and MRI-guided linear accelerators (MRI-LINACs). In each part, we discuss the historical evolution of the developments, technical developments, and clinical applications.

지수분포를 따르는 가속수명자료의 최우추정법에 기초한 경험적 베이즈 예측분석

조건호,이우동,하일도 慶山大學校 基礎科學硏究所 1997 基礎科學 Vol.1 No.2

본 논문은 지수수명분포에서 제2종 중도절단된 가속수명자료를 이용하여 고장률의 사전분포의 평균을 알 때, 정상조건하에서 하나의 미래 관찰치의 예측문제를 사전분포의 모수에 대하여 최우추정량(Maximun Likelihood estimator)을 이용하는 경험적 베이즈 접근방법을 적용시켜 경험적 베이즈 예측분포와 예측구간에 대하여 연구하였다. In accelerated life tests(ALTs), the failure time of a test item is observed under high stress conditions, and based on these data, one intrests statistical inference on the parameters of lifetime distribution at the normal stress. Under the type-II censoring, we assume that the life distribution is exponential distribution. When the information on the prior is partially known, we device the empirical Bayesian analysis of ALTs data in order to obtain the empirical Bayesian predictive density and predictive intervals for a future observation under the normal stress level.

깁스표본기법을 이용한 와이블분포의 위험률에 대한 베이즈추정

조건호,이우동,신양규,윤용화 慶山大學校 基礎科學硏究所 1998 基礎科學 Vol.2 No.1

와이블분포를 따르는 표본을 이용하여 위험률을 베이지안 방법을 이용하여 추정한다. 깁스표본법을 베이지안 추정에서 사후확률의 분포를 구하는 방법에 적용하여 위험률에 대한 사후분포와 주변사후분포를 추정하는 방법을 제안한다. 그리고, 9개의 가솔린 정류에서 쓴 sdufwjsekfrlrn(heat exchanger)에 대한 수명시간자료를 이용하여 제안된 방법으로 위험률에 대한 베이즈추정량을 구하고 최우추정량과 비교한다. In this paper, a Bayesian estimation of the hazard rate function of Weibull distribution is considered. Using Gibbs sampling approach, the posterior distribution of hazard and Bayes estimator of hazard are presented. Using 9 heat exchanger data, the proposed method is illustrated.

Diamond-Like Carbon 코팅을 이용한 금속 장식 용구의 칼라링 및 디자인연구

변건호,김형준,최형우,권도현 한국공예학회 2001 조형디자인연구 Vol.4 No.2

The usual methods of coloring metal ornaments include surface anodizing, plating and painting. However, the anodizing method can apply to AL materials only and the plating method has been causing a severe environmental problem because of the toxicity of materials used. For these methods, surface deteriorations such as decoloration, scratch and corrosion also occur after long-time use. Therefore, a better surface treatment method is needed. This study was conducted to improve corrosion resistance and wear resistance of metal ornaments, and increase their added value by means of the DLC(Diamond-Like-Carbon) coating method, and to expand the range of its application. This study examined the characteristics of the DLC for coloring metal ornaments and the ornamental design for practical application. Coating metal ornaments could be considered as one of promising fields for application of DLC DLC film is very suitable as a coating material because it is an amorphous carbon material based on covalent bond and therefore has excellent hardness, wear resistance, lubricative property, chemical stability and light transmittance. DLC coating film was formed by the PECVD method using 13.56MHz rf plasma and CH4 gas as a material gas. At this time RF power, working pressure, transmittance according to kind and amount of auxiliary gas, and changes in optical band gap were observed. It was shown that the higher the RF power and working pressure, the lower the optical bang gap. This could be demonstrated by observing the amount of carbon-hydrogen bond by means of FT-IR. It was shown that addition of hydrogen and nitrogen would the optical band gap because they serves to break the carbon-hydrogen bond at the time of vapor deposition. The direction of design was set up in the manner that the DLC coating film could be effectively deposited on the surface of an ornament. Design was based on geometric figures and minimalism with plane elements accentuated. Accentuated, partial coating or simple, whole coating was induced by combining quadrangles, triangles and circles basically.

지수분포를 따르는 가속수명자료의 적률추정법에 기초한 경험적 베이즈 예측분석

조건호,이우동,하일도 慶山大學校 基礎科學硏究所 1997 基礎科學 Vol.1 No.2

본 논문은 지수수명분포에서 제2종 중도절단된 가속수명자료를 이용하여 고장률의 사전분포의 평균을 알 때, 정상조건하에서 하나의 미래 관찰치의 예측문제를 사전분포의 모수에 대하여 적률추정량에 기초한 불편추정량(unbaised estimator)을 이용하는 경험적 베이즈 접근방법을 적용시켜 경험적 베이즈 예측분포와 예측구간에 대하여 연구하였다. In accelerated life tests(ALTs), the failure time of a test item is observed under high stress conditions, and based on these data, one intrests statistical inference on the parameters of lifetime distribution at the normal stress. Under the type-II censoring, we assume that the life distribution is exponential distribution. When the information on the prior is partially known, we device the empirical Bayesian analysis of ALTs data in order to obtain the empirical Bayesian predictive density and predictive intervals for a future observation under the normal stress level.

정신분열증 입원환자에서 니코틴과 항정신병 약물의 상관관계 규명을 위한 니코틴 패취 적용 연구

반건호,유희정,윤도준,김종우,이기철 대한생물치료정신의학회 2000 생물치료정신의학 Vol.6 No.1

연구목적 : 정신분열증 환자는 흡연율이 높고, 그에 따라 항정신병 약물 투여량이 늘어나고, 약물에 의한부작용은 오히려 감소한다고 알려져 있다. 이러한 연구에서 방법론적 문제로는 실제 니코틴 용량을 측정하지 않았다는 점이다. 본 연구는 담배보다 니코틴의 주요 대사물인 코티닌을 측정하여 방법론적 오류를 최소화하고자 하였다. 방법 : 정신분열증으로 진단받은 입원환자 중 니코틴 패취군 8명, 대조군 8명을 설정하였다. 5일간 패취를 붙인 후 혈액에서 코티닌을 측정하였고, 정신증상의 정도를 알기 위하여 PANSS, 약물의 추체외로 부작용 측정을 위하여 ESRS를 실시하였다 일일 약물용량을 chlorpromazine 동량으로 환산하여 기록하였다. 결과 : 코티닌 수치와 정신증상, 추체외로부작용, 약물용량 사이에는 유의한 차이가 없었다. 결론 : 코티닌은 항정신병 약물의 작용에 영향을 미치지 못하였다. 단, 향후 연구에서는 니코틴 패취의 양을 증량하여 사용하므로써, 코티닌 용량에 따라 항정신병 약물효과에 영향을 미칠 수 있는지를 검증해야 할 것이다.

잉어, Cyprinus carpio 雌性發生 二倍體 誘導

鄭佑鍵 國立統營水産專門大學 附設 水産科學硏究所 1992 수산과학연구소보고 Vol.3 No.-

잉어의 第2棘體 放出抑制에 의한 雌性發生二倍體를 유도하고자 백련어 精子의 遺傳的不活性化를 위한 適正 紫外線 照射濃度와 수정난의 倍數化유도를 위한 수온 자극의 처리조건에 대하여 검토하였다. 백련어 精子의 遺傳的 不活性化를 위한 적정 紫外線 照射濃度는 6,000erg/mm^2이상이었으며, 잉어난과 수정 후 수온자극처리에 의한 倍數化 유도는 수정 5분 후 0℃에서 30분간 처리하였을 때 29.5%로 가장 양호하였다. 성장은 부화 후 5개월째 正常二倍體는 체중 31.5~79.1g(평균 56.3±10.68)인 반면 雌性發生二倍體는 체중 12.8~99.6g(평균 58.9±20.76)으로서 분포의 범위가 넓었다. To induce the gynogenetic diploids of common carp (Cyprinus carpio) by the retention of the second polar body, the condition of ultraviolet irradiation for the inactivation of silver carp spermatozoa and temperature shock on the fertilized common carp eggs with spermatozoa was evaluated. And the growth of the gynogenetic diploids was also compared with that of normal control diploids. The appropriate concentration of UV irradiation for the inactivation of silver carp spermatozoa was more than 6000 erg/mm^2, 29.5% of the gynogenetic diploids were induced when the eggs were hold at 0℃ for 30 min at 5 min after fertilization. During 5 month after hatching the gynogenetic diploids and normal control diploids grew to 31.5-79.1(mean 56.3±10.6) and 12-8-99.6g (58.9±20.76) in body weight, respectiviely.

凍結鷄肉의 品質變化에 關한 硏究 : Ⅳ. 凍結 冷藏時의 理化學的 變化

金建培,李根雨 군산대학교 1986 群山水産專門大學 硏究報告 Vol.20 No.3

The quality variation of the frozen chicken meat pretreated with the various methods were studied during the cold storage. For the purpose of this study, the frozen chickens as samples were divided into five groups, T1 group (untreated), T2 group (treated with 1% ascorbic acid), T3 group (7.5% potassium sorbate), T4 group (5% NaCl) and T5 group (mixed with 7.5% potassium sorbate and 1% ascorbic acid). All samples were kept the cold storage for 90 days, the item of investigation on the thawed samples were pH, water holding capacity, changes of drip, P.O.V. and T.B.A. The values of pH in T3, T4 and T5 groups were continuously increased according to the storage days, but those in T1 and T2 groups were decreased after 60 days (p〈0.01). The water-folding capacity was the lowest (66.22%) in T, group and the higest (70.72%) in T5 group, and the relatively stable in T4 and T5 groups. The free drip level was the highest as 5.15% in T1 group and the lowest as 1.6% in T5 group, and the expressible drip was relatively little in T4 and T5 groups compared with other groups (p〉0.05). The value of P.O.V in T1 group was the highest as 10.2 meq/Kg and the lowest as 4.7 meq/Kg in T5 group (p〈0.01). The value of T.B.A. was also the highest as 0.507 in T1 group and the lowest as 0.232 in T5 group (p〉0.05). The store ability of the frozen chicken meat was good in T5 group.

축차확률비 검정을 이용한 실제값과 Wald 근사값의 정확도에 관한 연구

조규민,조건호,박용우 대구대학교 산업기술연구소 1993 産業技術硏究 Vol.12 No.-

Sequential analysis refers to techniques for testing hypotheses or estimating parameters when the sample size is not fixed in advance but is determined during the course of the experiment by criteria which depend on the observations as they occur. In this paper, We considered the properties of Wald approximations in S.P.R.T. and compared exact value with the Wald approximations by using a example and then found the error probabilities α_(0),α₁and expected sample size (average sample number) E(N) by S.P.R.T in AR(1). Conclusively, We discovered that Wald approximations tend to over-estimate the true error probabilities.

메기, Parasilurus asotus 사료의 최적 단백질 함량

강석중,정우건 國立統營水産專門大學 附設 水産科學硏究所 1994 수산과학연구소보고 Vol.5 No.-

새로운 양식 대상종으로 메기의 생산량 증가를 위하여 사료 중 최적 단백질 함량을 설정 하고자 실험한 결과는 다음과 같다. 평균 체중 약 7g되는 메기 치어의 체중은 사료중 단백질 함량 25%~55% 사이에서 단백질 함량이 높은 사료를 공급할수록 증가하였으나,근육 단백질의 증가는 45% 부근에서 최고치에 달하였으며,그 이상으로 사료 단백질 함량을 증가시켜도 변화가 없었다. 단백질 효율 및 정미 단백 이용율은 25% 부근에서 최고치에 달했지만 45% 부근에서 일시적으로 증가하여 단백질 함량 45% 실험구가 가장 양호한 것으로 나타났다. 따라서 멸치분을 단백질 원으로 하였을 때 메기 치어 사료의 최적 단백질 함량은 45%로 사료된다. Feeding trials were conducted for a test of the optimum dietary protein levels for the fingerling Korean catfish, Parasilurus asotus. The growth response was examined in terms of weight gain, feed coefficient, protein efficiency ratio and net protein utilization for 8 weeks at 23~27℃. Within a range of 25 to 55% crude protein levels in the diet, the body weight increased while the dietary protein level increased. Accumulation of protein in the body reached the maximum when the crude protein level in the diet was at 45%. These results indicate that the optimum dietary protein level of fingerling Korean catfish was about 45% when anchovy meal was used as the protein source.