냉간압출에 의한 새로운 헬리컬기어의 제조에 관한 연구

崔載燦,趙海龍,權赫洪 부산대학교 공과대학 1991 工大論文集 Vol.42 No.-

A new helical gear forming process by cold extrusion was proposed and its numerical solution program based on the upper bound method was developed. In the analysis the involute curve was used as a shape of die and the upper bound method was used to calculate energy dissipation rate. By this method the power requirement and optimum conditions necessary for extruding helical gear were successfully calculated. These numerical solutions were in good agreement with experimental data. In the experiment, die life of a new was greatly improved compared with hat of Samanta process and 4~5 class helical gear of KS standard for automobile transmission was successfully manufactured.

全身麻醉中 發生한 不適合輸血의 症例報告 : A Case Report

崔泳錫,李奎順,金勇赫,辛正順 한국의 현대의학사 1974 한국의 현대의학 Vol.7 No.1

신비체험과 해리성향과의 관계

최낙경,이상혁,우용일,이만홍,현용호 대한신경정신의학회 2000 신경정신의학 Vol.39 No.4

신비체험은 종교의 핵심경험이라고 일컬어질 만큼 종교계에서 가치 있게 평가되고 있으며 여러 사회집단에서도 관심의 대상이 되어왔다. 오래 전부터 심리학자들과 정신의학자들이 신비체험에 대해 관심을 가져 왔지만 그것의 개인적이고 주관적인 특성 때문에 과학적인 접근이 어려웠으며 단지 신비체험의 특성을 나열하고 묘사하는데 그쳤다. 최근 일부 정신병리학자들은 신비체험을 해리현상의 하나로 보는 주장도 있다. 한편 해리는 어린 시절의 외상경험과 연관이 있고 정신병리가 많을수록 해리경향성이 높아진다는 보고가 있어 왔다. 본 연구는 종교인중 신비체험을 경험하지 않은 사람(비신비체험군) 35명을 대조군으로 하여 종교인중에서 신비체험을 경험한 사람(신비체험군) 42명과 해리경향성, 정신병리, 외상경험을 비교하였다. 연구도구로는 한국어판 해리경험 척도, 간이정신진단검사, 외상유무를 묻는 질문지를 이용하였다. 그 결과, 해리경향성은 신비체험군이 비시비체험군보다 유의미하게 높았으며 외상경험도 유의미하게 높게 보고하였다. 그러나 정신병리상의 두드러진 차이는 발견되지 않았다. Mystic experience is highly evaluated so as to be called as core of experience in the religious world and also becomes the subject of concern among various social groups. Psychologists and psychiatrists are concerned about it, but because of its individuality and subjectivity, the scien-tific approach was difficult so that only the description of mystic experience has been researched fo far. There is a current report saying that mystic experience is the one of the dissociative pheno-menon. And there are a lot of reports saying that dissociation is related to childhood trauma experience and rises as much as psychopathological tendencies exist. Consequently, based on the reference that mystic experience is connected with dissociation, the study has been progressed to find out the level of dissociation, psychopathology and trau-ma experience for religious people who experienced mystic experience but excluding patients. Among them, it has been compared between group of non-mystic experience(n=35) and group of mystic experience(n=42). We used Dissociative Experience scale-Korean version(DES-K), Symptom Checklist-90-Revised(SCL-90-R), questionnaire about trauma. The result is that the group of mystic experience had a significantly higher tendency to have dissociation and trauma experience than group of non-mystic experience. However, the differ-ence of psychopathology has not been found.

화재감지센서용 PZN-PSS-PZT계 초전재료의 전기적 특성에 미치는 MnO₂첨가제의 영향

金龍赫,白東鉉,崔逸壽 (社)韓國火災 ·消防學會 1995 한국화재소방학회논문지 Vol.9 No.2

In this study, the effect of MnO_2 additive on the electrical characteristics of PZN-PSS-PZT Pyroelectric materials for the fire detactor was studies. PZT ceramics used this experimental is 4 composite system [Pb(Zn_1/3 Nb_2/3)O_3 +Pb(Sn_1/3 Sb_2/3)O_3+PbTiO_3+PbZrO_3]. The dielectric constants and dissipation factors decreases as to MnO_2 concentration increases. At the MnO_2 0.5(ωt%), Pyroelectric coefficient shows 8(10^-8C/cm^2℃) which have the highst value among other additive contents. It is found that output voltage maximum peck at MnO_2 0.7(ωt%) is associated with the higher pyroelectric coefficient and Lowered dielectric constant.

중간레진의 친수성이 상아질 접착에 미치는 영향

김용성,박상혁,최기운,최경규 대한치과보존학회 2007 Restorative Dentistry & Endodontics Vol.32 No.5

마이크로 컨트롤러를 이용한 지능구조물의 진동제어시스템 개발

황재혁,홍의표,이원석,최용훈 한국항공대학교 항공우주산업기술연구소 2003 航空宇宙産業技術硏究所 硏究誌 Vol.13 No.-

본 논문에서는 유연구조물의 진동을 제거하기 위하여 압전 세라믹(PZT)을 감지기와 작동키로 이용하였다. 진동을 제거하기 위한 제어 방법은 위치 되먹임 제어와 속도 되먹임 제어 두가지 방법을 사용하였다. 위치 되먹임 제어는 구조물의 각 지점의 위치를 감지해 내고 이를 역으로 걸어 주는 것이고 속도 되먹임 제어는 유연부착물의 각 지점에서의 속도에 대한 정보를 역으로 걸어 주는 것이다. 즉, 압전 감지기의 감지 전압을 이용해서 속도 되먹임 제어를 할 수 있다. 적용된 두 제어 방법 모두 개회로일 때 보다 좋은 성능을 나타내었다. 그러나 위치 되먹임 제어가 스필오버(spill-over)가 심했고 속도 되먹임 재어보다 정착시간(Settling Time)이 더 길었다. 본 실험에서는 속도 되먹임 제어가 적은 에너지로도 위치 되먹임 제어보다 좋은 성능을 보였다. 제어시스템을 구축하기 위해서 마이크로 컨트롤러를 사용한 제어보도를 설계하고 제작하였다. 제어 보드에 사용된 마이크로 컨트롤러는 Intel 80c196ke를 사용하였으며 마이크로 컨트롤러의 A/D, D/A 기능을 보완하기 위해서 A/D, D/A 보드를 제작하였으며, 사용자 편의와 원거리 제어를 위해서 사용자 보드를 제작하였다. 본 실험에서 제작한 제어 보드는 본 실험에 쓰인 외괄보 뿐만 아니라 압전 세라믹을 이용한 모든 구조물의 능동진동제어에 쓰인 수 있도록 제작되었다.

중학교 컴퓨터 교육의 실태 분석을 통한 개선 방안 : 부산광역시 중학교를 중심으로 On the Basis of Middle School in Busan Metropolitan City

김용일,최재혁 한국컴퓨터교육학회 2006 컴퓨터교육학회 논문지 Vol.9 No.2

가토의 하악골 연장에서 잠복기간 단축의 영향

김용하,설정현,최준혁,강무석 大韓成形外科學會 1999 Archives of Plastic Surgery Vol.26 No.5

To evaluate the effect of shortening the latent period for distraction osteogenesis, the authors experimented with distraction osteogenesis for a 24-hour latent period in the mandibles of rabbits. This study was carried out on 32 New Zealand white rabbits, each weighting 2000 to 2500 gm. Twenty animals were used for the control group and 12 for the experimental group. A unilateral external fixation device was applied to the left mandible. The mandibles were lengthened at 1 mm per 24 hours for 10 days. Five rabbits from the control group and three from the experimental group by random selection were sacrificed on the first day, and at the second, fourth and eighth week of the consolidation period. After lengthening bone densities at the site of the left mandibular bony lengthening were measured by quantitative computer tomography (QCT) and dual energy x-ray absorptiometry (DXA). As a result, the DXA value showed no difference compared to the control group after two week's consolidation. The trabeculae were thicker and had begun to be surrounded by lamellar bone both in the control and experimental groups histologically. In conclusion, the results of this study indicate that the osteogenetic effect in the experimental group was nearly the same as in the control group. If stable fixation and minimal periosteal dissection were performed during the procedure, the latent period would not be an important factor in distraction osteogenesis of membranous bone.

최근 10년간 마취에 관한 임상적 고찰

신용섭,임정혁,최세진 충남대학교 의과대학 지역사회의학연구소 1988 충남의대잡지 Vol.15 No.1

To evaluate the specificity and the historical trends of the anesthetic agents and anesthetic methods used in Chungnam National University Hospital, anesthetic experiences of 21, 595 in total performed at Chungnam National University Hospital from January 1977 to December 1986 were analyzed stastically and clinically according to age, sex, surgical department, physical status, elective and emergency surgery, premedicants, induction agents, anesthetic methods, main anesthetic agent, anesthetic technique and muscle relaxants. The results were as follows: 1. The number of cases has been steadily increased. Considerable increase in the cases has been noted since 1985, when Chungnam National University Hospital was enlarged. 2. The distribution of the number of patients according to the age were 15, 332 cases (70. 9%) in the group of 16-60 years. 3. There were 12, 109 male (56. 1%) and 9,486 female (43.9/'0) cases. 4. 6, 128 cases (28.4%) were in general surgery, 4, 276 cases (19. 8%) in orthopedic surgery, 3, 138 cases (14.5%) in OB-GY and 1, 888 cases (8.7%) in ENT in order of numbers. 5. According to the ASA classification of physical status, most of the cases were belonged to the class 1 (33. 9%) class 2 (26.6%), class 1E (14.2%) and class 2E (12.5%). Almost cases were relatively in good physical status. 6. The rate of elective to emergency was 66. 5% (14, 370 cases) to 33. 5% (7, 225 cases). 7. As premedicants, a group of atropine, diazepam and hydroxyzine (33.4%) was given most frequently. Recently, glycopyrrolate has been used increasingly. 8. Thiopental sodium has been mainly used for intravenous induction agent. 9. General anesthesia has been used as the main method of anesthesia. 10. Halothane was the most commonly used anesthetic agent. Since 1979, the use of enflurane has been increased yearly. 11. The semiclosed circle breathing system was mainly employed. 12. Succinylcholine was given to most cases. Pancuronium was the most commonly used nondepolarizing muscle relaxant. Vecuronium has been used since 1986.

스위치드 릴럭턴스 전동기를 위한 구동시스템의 역률개선과 고효율에 관한 연구

한대희,최준혁,윤용호,정동효,김도군,원충연 성균관대학교 2003 학술회의지원논문목록집 Vol.2003 No.-

Switched Reluctance Motor (SRM) offers the advantages of simple and robust motor construction, high speeds and high efficiencies over a wide operating range of torque and speed, excellent controllability. However, SRM has the disadvantages of high current harmonics, and low power factor because of a capacitor filter is inserted in the power converter and inductance of SRM is high, it has pulse waveform of current. This paper deals with an energy efficient converter fed SRM system with the reduced harmonics and improved power factor and with higher efficiency. The validity of the proposed scheme is verified via experiment. We are implemented the proposed control system using 8OC196KC micro-controller.