Systolic Array를 이용한 2차원 CMT

朴敏植,金英百,郭勳星 전북대학교 전자산업개발연구소 1990 전자산업연구 Vol.1 No.-

This paper proposes systolic array for 2-D C-Matrix Transtorm(CMT). Compared the conventional method with the proposed 2-D CMT without matrix transpolsition, it is required the more PE's, but the less latency. Also, it is shown that the systolic array VLSI implementation for 2-D CMT is feasible.

열복사의 색수차 공간여과를 이용한 레이저 용접 감시기술

김민석,백성훈,박승규,정진만,김철중 한국레이저가공학회 1999 한국레이저가공학회지 Vol.2 No.2

An innovative real-time weld monitoring technique using chromatic filtering of the thermal radiation from a weld pool is developed. This thermal radiation from the weld pool is focused on an aperture and the transmitted thermal radiation is monitored at two wavelengths with high-speed single-element detectors. Due to the chromatic aberration introduced in the focusing optics, the transmittance curve of thermal radiation varies by the wavelength. Owing to this difference in the transmittance, the local variation of thermal radiation from the weld pool can be monitored by processing the two spectroscopic signals from two detectors. In this paper, the algorithms to monitor the laser power on the weld specimen and the focus shift are investigated and the performances of laser power and focus monitoring are shown for a pulsed Nd:YAG laser welding. The monitoring of the weld pool size variation is also discussed.

우울증 환자 치료에 있어서 Tianeptine과 Sertraline의 효과와 안전성 비교

이민수,강성민,기백석,연병길,오병훈,이철,채정민,백인호 大韓神經精神醫學會 2001 신경정신의학 Vol.40 No.2

연구목적: 주요 우울증의 치료에 있어서 티아넵틴과 써트랄린의 임상적 효과와 안정성을 비교하기 위하여 연구를 시행하였다. 방법: DSM-IV 진단 기준에 의거하여 주요 우울증의 진단기준에 부합되고 17항목 해밀턴 우울척도 점수가 14점 이상인 환자를 대상으로 하였다. 총 40명의 환자를 무작위적 방식에 따라 티아넵틴 치료군과 써트랄린 치료군으로 분류하였다. 선탠된 환자에서 다른 항우울제를 복용하고 있는 경우 7일 이상의 약물 배설기간을 가진 후 티아넵틴과 써트랄린을 각각 6주간 투여하였으며, 기준점, 1주후, 2주 후, 4주 후, 6주 후에 HAM-D, MADRS, 그리고 CGI, COVI 등을 사용하여 평가하였다. 본 연구기간 중 발생된 모든 부작용은 부작용의 발생 및 소실 시기, 심한 정도, 발생 빈도, 관련 조치 및 결과에 대하여 증례기록서에 기록하도록 하였다. 결과: 30명(티아넵틴군 15명 ; 써트랄린군 15명)이 6주간의 연구를 완결하였고 티아넵틴 치료군에서는 1일 37.5mg을 투여하였으며 써트랄린군에서는 1일 평균 64.0±22.5mg을 투여하였다. 본 연구 결과 HAM-D, MADRS, CGI 상에서 두 군 모두에서 치료 1주 후부터 유의한 감소를 나타내었으며 이는 2주 후, 4주 후, 6주 후에도 지속적인 감소를 보였고 두 군간에 항우울 효과의 차이는 없었다. 활력징후, 일반 혈액학, 생화학, 심전도 검사 등에서는 두 군 모두 유의한 변화는 없었다. 티아넵틴과 관련된 부작용으로 흔히 보고한 증상은 오심(33.3%), 복부 불쾌감(26.7%), 구강 건조(20.0%), 두통(13.3%)등 이었고 써트랄린 치료군에서는 구강 건조(53.3%), 두통(46.7%), 오심(33.3%), 그리고 식욕 부진(33.3%)등으로 티아넵틴군에서 보다 적은 발현빈도를 보였다. 결론: 티아넵틴은 우울증의 치료에 있어서 효과적이고, 내약성이 우수한, 안전한 항우울제이다. Objective: This study was designed to evaluate the efficacy and safety of tianeptine and sertraline in the treatment of patients with depression. Method: The study was done on the patients with major depression diagnosed by DSM-IV, who had aHamilton Rating Scale for Depression(HAM-D) score ≥ 14 on the first 17 items of the HAM-D. A total of 40 patients were randomly assigned to tianeptine group and sertraline group. Tianeptine and sertraline were prescribed to each group. 6 weeks of each medication was carried out after 7 days of drug excretion period. Evaluation using 17 item HAM-D, Montgomery and Åsberg Depression Rating Scale(MADRS), Clinical Global Impression Scale (CGI), and Covi Scale was done on the baseline and after 1 week, 2 weeks, 4 weeks, and 6 weeks. Regrding all side effects that had occurred during the period of our study such as their developed/disappeaed time, severitien, incidences, managements and results have been recorded. Results: A total of 30 patients(tianeptine group 15 ; sertraline froup 15) finished the 6 weeks of research. 37.5mg of the daily dose was regularly prescribed to the tianeptine group, the average amount of 64.0±22.5mg of the final daily dose was prescribed to the sertraline group. Total 17 item HAM-D scores, total points of MADRS and CGI showed significant decrease after 1 week in each treatment froup and continous decrease after 2, 4 and 6 weeks ; and no difference was found between tianeptine group and sertaline group in the antidepressant efficacy. Also there were no significant changes in vital sign, CBC, chemistry, and EKG in each treatment group. The common reported side effects of tianeptine were nausea(33.3%), epigastic distress(26.7%), dry mouth(20.0%), headache(13.3%) and those of sertraline were dry mouth (53.3%), headache(46.7%), nausea(33.3%), anorexia(33.3%). Conclusion: According to the results, tianeptine was effective in improvement of depressive symptoms and was well tolerated and safe in patients with depression.

압입유동특성 평가를 위한 진변형률 정의에 관한 고찰

전은채,백민경,김성훈,박주승,권동일 대한금속재료학회 2004 대한금속·재료학회지 Vol.42 No.12

Continuous indentation test is getting more used to derive indentation flow curve. The overall deriving algorithm is relatively well-established, the details of the algorithm are, however, still argued. One of the arguments is the definition of true strain which constitutes the indentation flow curve. In this study, work-hardening exponent was adopted for determining what definition is appropriate to obtain accurate indentation flow curve since work-hardening exponent is affected by only the definition of true strain not by other constants. The effect of calibrating contact depth was eliminated using finite element analysis. Finally, the definition based on tangent function was determined to be proper for deriving the indentation flow curve. (Received September 8, 2004)

전방 또는 전측방 흉수 종양 수술에서 후측방도달법

조경석,박춘근,성재훈,허필우,박춘근,백민우,김달수,강준기 대한신경외과학회 1997 Journal of Korean neurosurgical society Vol.26 No.5

A Preliminary Investigation on Geochemical and Mineralogical Characteristics of Ogcheon Uranium Zone for Natural Analogue Study

Min-Hoon Baik,Dawoon Jeong,YeoJin Ju,Ji-Hun Ryu 한국방사성폐기물학회 2021 한국방사성폐기물학회 학술논문요약집 Vol.2021 No.11

Geochemical Behaviors of Uranium in Groundwater Samples From Natural Analogue Study Sites in Ogcheon Metamorphic Belt

Min-Hoon Baik,YeoJin Ju,Dawoon Jeong,Ji-Hun Ryu 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.2

The mobility of uranium (U) in various disposal environments of a deep geological repository is controlled by various geochemical conditions and parameters. In particular, oxidation state of uranium is considered as a major factor to control the mobility of uranium in most of geological environments. In this study, therefore, we investigated the geochemical behaviors of uranium in grounwater samples from natural analogue study sites located in the Ogcheon Metamorphic Belt (OMB). Groundwater samples were taken using a packer system from Boeun Hoenam-myun site and Geumsan Suyoung-ri site where several boreholes were dilled with various depths. The geochemical properties and parameters such as temperature, pH, Eh, EC, and DO were directly measured in the site using an in-line measurement method. The concentrations of major cations and anions in the groundwater samples were measured by using ICP-OES (Inductively Coupled Plasma-Optical Emission Spectrometry) and IC (Ion Chromatography), respectively. The concentrations of trace elements including U and Th were measured by using ICP-MS (Inductively Coupled Plasma-Mass Spectrometry) The concentrations of U in the groundwater samples are very low for the Hoenammyun site (0.03~0.69 ppb) and Suyoung-ro site (0.39~1.74 ppb) even though the two sites are uranium deposits and redox conditions are weakly oxidizing. The speciation, saturation index (SI), pH-Eh (Poubaix) diagram were calculated using the Geochemist’s Workbench (GWB 9.0) program and the recent OECD/NEA thermochemical database for U. Calculation results for U speciation in the groundwater samples show that major dissolved uranium species in the groundwater samples are mainly as calcium uranyl carbonate complexes such as Ca2UO2(CO3)3(aq) and CaUO2(CO3)3 2- for almost all groundwater samples. The calculated results for SI and Poubaix diagram also show that the dominant uranium solid phase is a uranyl silicate mineral, uranophane (Ca(H2O)(UVIO2)2 (SiO2)2(OH)6), not uraninite (UIVO2). Since the determination of Eh values for natural groundwater samples is very difficult and uncertain work, we analyzed and discussed the effect of Eh on the geochemical behaviors of U in the groundwater. However, these calculation results are not consistent with the observation for U minerals in rock samples using electron microscopic techniques. Thus, we need further studies to explain the discrepancy between calculation and observation results.

Experimental Study on Uranium Sorption onto Silica Colloids: Effects of Geochemical Parameters

Baik, Min-Hoon,Hahn, Pil-Soo Korean Nuclear Society 2001 Nuclear Engineering and Technology Vol.33 No.3

In this study, sorption experiments of uranium onto silica colloids were carried out and the effects of important geochemical parameters such as pH, ionic strength, carbonate concentration, colloid concentration, and total concentration of uranium were investigated. The sorption coefficients of uranium for silica colloids named as pseudo-colloid formation constants were about 10$^4$~ 10$^{5}$ mL/g depending on the experimental conditions. The effects of the geochemical parameters were found to be important in the sorption of uranium onto silica colloids. A Langmuir type sorption isotherm of uranium between silica colloids and the solution phase was also presented. The sorption mechanisms were explained by analyzing the effects of the geochemical parameters.

Evaluation of Distribution Coefficient of a Metal Ion in the Presence of n Chelating Agent

Baik, Min-Hoon,Lee, Kun-Jai The Korean Society for Energy 1992 에너지공학 Vol.1 No.1

A mathematical model has been developed for an analytical calculation of distribution coefficient (K$_1$) in the presence of a chelating agent, The newley formulated K$\_$D/ is given as a function of the mole fraction of a free metal ion in the solution, ${\beta}$, and will serve as an alternative for the tedious individual measurements of K$\_$D/. This formulation will be used to analyze the effects of the presence of chelating agents on the adsorption capacity of geologic media such as clay minerals and soils. The present method may be a significant progess for the evaluation of the transport phenomena and separation processes of metal ions (or radionuclides) in the presence of chelating agents.

A Geochemical Study on the Uranium Mobility in a Deep Geological Repository: A Natural Analogue Approach Using a Uranium Deposit in the Ogcheon Metamorphic Belt

Min-Hoon Baik,YeoJin Ju,Dawoon Jeong,Ji-Hun Ryu 한국방사성폐기물학회 2023 한국방사성폐기물학회 학술논문요약집 Vol.21 No.1

The mobility of uranium (U) in the environment of a deep geological repository is controlled by various geochemical conditions and parameters. In particular, oxidation state of uranium is considered as a major factor to control the mobility of uranium in most of geological environments. In this study, therefore, we investigated the mobility of uranium in a deep geological repository by a natural analogue approach using a uranium deposit in the Ogcheon Metamorphic Belt (OMB). Uranium contents of rock samples from the study site ranged from 1.3 to 71 ppm (average 17.4 ppm). Uranium minerals found in the study site were mostly uraninite (UIVO2+x) and uranothorite ((UIV, Th)SiO4). The concentrations of U in the groundwater samples were very low (0.025~0.690 ppb) even though redox conditions are weakly oxidizing. Calculation results for U speciation in groundwater samples showed that major dissolved uranium species in the groundwater samples are mainly as calcium uranyl (UO2 2+) carbonate complexes such as Ca2UO2(CO3)3(aq) and CaUO2(CO3)3 2-. However, the activity ratios between 234U and 238U (AR(234U/238U)) showed U behavior in reducing conditions although the groundwater conditions were not reducing conditions and major dissolved U species were U(VI) species. Results from electron microscopic analyses for rock samples showed that major uranium minerals were U(IV) minerals such as uraninite and uranothorite. We could not identify other uranyl minerals and altered minerals from uraninite. This means that the geochemical condition of the study site has been maintained a reducing condition although the groundwater condition was a weakly oxidizing condition. Thus, the dissolution of uranium is strongly limited by the low solubility of uraninite. It is not obvious how the reducing condition of the study site has been maintained. Reducing agents such as pyrite, organic materials, and reducing bacteria might contribute to maintaining the reducing condition although further studies will be necessary. Results from this study imply that uranium mobility will be greatly limited by low dissolution of uraninite into groundwater if the reducing condition is well reserved. This limited mobility of uranium will be also contributed by low possibility of uraninite alteration into uranyl minerals which have a higher solubility than uraninite.