가포화 인덕터를 사용한 ZVS PWM DC/DC 컨버터의 해석

具本鎬 慶一大學校 1997 論文集 Vol.14 No.2

The conventional high frequency phase-shifted full bridge zero voltage switching DC-DC converter has a shortcoming that it has not wide zero voltage switching(ZVS) range. Also the basic full bridge zero voltage switching PWM converter is not suitable for applications with wide ZVS range. In order to compensate this problem, saturable inductor was inserted instead of resonant inductor to reduce duty cycle loss and secondary parasitic ringing problem without additional circuits. This method can alleviate the switching losses, EMI problems, and increase the effective duty. Also this study is verified by the simulation, the analysis and the experiment.

직렬 공진형 컨버터의 슬라이딩모드 전압제어

具本鎬,任成雲 慶一大學校 1992 論文集 Vol.8 No.1

This paper presents a method to control the output voltage of QSRC using sliding mode control theory. State equation is derived for the system that introduced control theory is applied to equivalent circuit of QSRC. The parameter of control rule selected in order to minimize the effect of load variation. By proposed control method, it was shown that output voltage of QSRC was controlled continuously. Robustness of proposed controller was pointed out via computer simulation and experiment.

쥐의 망막 미세구조에 미치는 급성 메탄올 중독에 대한 에탄올의 효과 관찰

이호경,유진형,구본술 인제대학교 1983 仁濟醫學 Vol.4 No.3

복강내 메탄올 주입으로 급성 메탄올 중독을 일으킨 쥐와 메탄올 주입 직후, 8시간 후 및 24시간 후에 에탄올을 투여한 쥐의 망막 미세구조를 관찰하여, 메탄올 주입 직후와 8시간 후에 에탄올을 투여한 쥐에서 메탄올에 의한 망막 조직 파괴가 경감되었음을 관찰하였다. Methanol is a widely-used chemical which can cause serious visual loss by accidental ingestion, and ethanol therapy has been considered effective in maintaining life as well as preserving vision, if performed appropriately. To provide histopathologic basis of ethanol therapy in acute methanol poisoning, which is still obscure, methanol was injected intraperitoneally to the rat and ethanol therapy was carried out immediately after, 8 hours after, and 24 hours after methanol injection. One month later, specimens of retina were obtained and examined using electron microscope, comparing with only methanol-injected case. The results were as follows. 1.Ultrastructural examination of retina of the only methanol·injected rat revealed such histologic changes as retinal ganglion cell degeneration, vacuole formation in nerve fiber layer, photoreceptor outer segment destruction, and separation of inter-pigment epithelial junction, which are compatible with clinically observed visual deterioration. 2.Retinal changes were much reduced in the rat which had received ethanol therapy immediately after methanol injection, but the reduction was not conspicuous in the 8 hour-interval ethanol treated rat. No differences were found between only methanol-injected rat and 24 hour-interval ethanol-treated case.

치경부 마모증 수복시 상아질 접착제가 변연누출에 미치는 영향

손호현,구본욱 大韓齒科保存學會 1987 Restorative Dentistry & Endodontics Vol.12 No.2

TRACT The purpose of this study is to evaluate the effect of dentin bonding agents on marginal leakage. V-shaped cavities were prepared on the faciocervical area of 140 extracted human teeth. In Groups of twenty cavities, they were restored as follow: Group 1 with enamel bonding resin and Silux, Group 2 Scotchbond and Silux, Group 3 enamel bonding resin and Heliomolar, Group 4 Dentin Adhesit and Heliomolar, Group 5 enamel bonding resin and Durafill, Group 6 Dentin Adhesive and Durafill, Group 7 Chembond. All specimens were thermocycled alternatively at 4? and 60? of 2% methylene blue dye solution, and sectioned faciolingually with diamond disk under water spray. The sectioned speci- mens observed with stereomicroscope.Following results were obtained: 1. The groups filled with Scotchbond-Silux or Dentin Adhesit-Heliomolar had appeared lesser marginal leakage compared with the groups with enamel bonding resin-Silux or enamel bond- ing resin-Helimolar. 2. The group filled with Dentin Adhesive-Durafill did not show the reduction of the marginal leakage compared with the group with enamel bonding resin-Durafill. 3. There was significant difference among the four dentin bonding agents. Scotchbond showed the greatest marginal sealing ability, and Dentin Adhesit was the next. The marginal sealing ability of Dentin Adhesive was the worst.

Pulse Oximeter를 이용한 치수생활력측정

이제호,구본경,이종갑 大韓小兒齒科學會 2000 大韓小兒齒科學會誌 Vol.27 No.1

치수 생활력 검사시 전통적인 방법으로 전기치수검사나 온도변화검사 등이 있다. EPT와 ice test 즉, 전기치수검사와 온도변화검사는 치아의 신경학적 반응에 의해 치아의 실활여부를 판단하는 방법으로 환자가 아동일 때는 정확한 반응을 얻기가 어렵고, 환자의 주관적 반응을 판단해야 하므로 객관적이지 못하고, 소아환자에게 좋지 못한 자극을 주어 행동 조절의 문제를 일으키며, 거짓 양성반응과 거짓 음성반응이 나올 수 있다는 등의 한계가 있다. 최근에는 전통적인 방법의 한계를 극복하려는 시도에서 혈관의 보전성을 평가하는 방법인 laser doppler flowmetry와 pulse oximeter를 이용하는 방법이 소개되고 있다. Pulse oximeter의 원리는 두 가지 종류의 파장의 빛을 귀, 손가락 등 생체의 말단에 투과시켜 발산된 빛과 감지된 빛간의 두 파장의 흡수비로 산소포화 정도를 알아내는 것으로서 이에 착안하여 또 하나의 생체 말단인 치아에 이를 적용하여 치아의 실활 여부를 판단하는 것이다. 이 보고에서는 치수 생활력 검사시 pulse oximeter의 사용 가능성에 대해 검증하고 이의 임상적용에 대해 기초적 자료를 제공하고자 함을 목적으로 했는데 생활치에서는 평균 96.3%의 산소 포화도를 실활치에서는 평균 0.0%의 산소 포화도를 얻어냄으로서 pulse oximeter가 치아의 실활여부 판단에 있어 유용한 진단도구로서의 가치가 있다는 것이 밝혀졌다. Traditionally, EPT and thermal tests were used as diagnostic methods for pulp vitality test. The thermal and electrical stimulation tests are the methods to determine the vitality of a tooth based on its neuronal response. These have certain limitations, one of them is the difficulty of approaching the correct result in case of treatment of children. The reason is management problem caused by the unpleasant stimulation. Also, the response from patients are not objective, and false positive or false negative could be happened. Recently, laser doppler flowmetry and pulse oximeter which evaluate vascular integrity are introduced-in an effort of overcoming to limitation of traditional methods. The principle of pulse oximeter is to find out level of oxygen saturation by ratio of the two pulses between emitted light and detected light penetrating them to the termination of body, such as ears or fingers. From this point of view, it can be applied to a tooth to determine its vitality. The objective of this study lies mainly on varifying pulse oximeter as a method of determining tooth vitality and providing basic data of its clinical implementation. The result of the research showed that level of oxygen saturation in vital teeth was average of 96.3% and 0.0% in pulpless teeth. As a comprehensive result, pulse oximeter could be an useful diagnostic equipment in determining of tooth vitality.

강압형 컨버터의 퍼지제어

盧澈均,具本鎬,任成雲 慶一大學校 1993 論文集 Vol.9 No.1

This paper presents output voltage control method of buck converter using fuzzy control theory. Output voltage is obtained by duty ratio as output of the fuzzy control. By proposed fuzzy control system, it is good characteristics in the steady state and the transient. The system have robust output characteristics that have nothing to do with load variation from no load to full load. This feature is verified through the computer simulations.

아데노이드 및 구개편도 절제술이 비저항과 비강 내 Geometry에 미치는 영향

나기상,박찬희,구본석,김영덕,김관호,박용호 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

수술 전 최소단면적이나 비강 부피는 아데노이드나 구개편도의 비대 정도와 상관관계를 보이지 않았으나 비저항은 아데노이드 비대 정도와 유의한 상관관계를 보였다. 구개편도 및 아데노이드 절제술 후 코막힘과 구호흡 증상의 유의한 호전을 보였다. 수술 후 비강의 최소단면적과 부피 등 nasal geometry는 통계적으로 유의한 변화가 없었으나 비저항은 수술 후 유의한 감소를 보였으며 수술 후 비저항의 감소 정도는 아데노이드 비대 정도와 유의한 상관 관계를 보였다 . 이상의 결과로 아데노이드와 구개편도의 비대를 보이는 소아에서 코막힘 증상을 일으키는 데는 아데노이드 비대가 주요 원인이 되며 주로 비강의 후방에 위치한 아데노이드의 mass effect에 의할 것으로 생각한다. The aim of this study was to determine whether adenoid or tonsillar hypertrophy and subsequent adenoidectomy and tonsillectomy affect pediatric nasal airway resistance and nasal geometry and to evaluate the relationships between the degree of hypertrophy and nasal airway resistance or nasal geometry. Thirty-two children, aged 3 to 15 years, selected for adenoidectomy and tonsillectomy due to chronic nasal obstruction and mouth breathing were enrolled. The size of adenoid was evaluated by cephalometric radiograph. The degree of tonsillar hypertrophy was graded clinically. Nasal airway resistance and nasal geometry was evaluated by active anterior rhinomanometry and acoustic rhinometry respectively. These measurements were repeated one month and three months post-operatively. The size of adenoid was found well correlated to preoperative nasal airway resistance. However, there were no correlations between the degree of tonsillar hypertrophy and preoperative nasal airway resistance or nasal geometry. Nasal geometry was not changed after operation. However, nasal airway resistance was reduced significantly at 3 months after operation and the size of adenoid was found well correlated to postoperative changes of nasal airway resistance.

2000학년도 학기제 현장실습제도의 효과 분석 및 1999학년도의 분석결과와의 비교 연구 : 현장실습의 교육적인 가치 및 운영적인 측면을 중심으로 based on the educational value and the operational aspect

金相吉,趙德鎬,李相鎬,具本及 大田産業大學校 2001 한밭대학교 논문집 Vol.18 No.-

The main purpose of this study focuses on the analysis of the effectiveness of the sandwich education system by comparing the educational value and operational efficiency between the 1999 and 2000 school years. This study is based on questionnaires from 67 students of the Division of Advanced Materials Engineering at Han-Bat National University, 13 major field professors who guided the students, and 18 industrial personnel who trained the students during the program. Students participated in the field experience from the beginning of September, 2000 to the middle of December in the same year. They were surveyed in the beginning of 2001. The results of the analysis are compared to the ones which were surveyed in the end of 1999 school year. The first part of the question is related to educational values of the program and the second part of the question consists of the operational aspect of the program. The results of the 2000 years program has much improved compared to that of the 1999school year. Many of the negative views students showed in 1999 have turned positive ones in 2000.

쌀, 옥수수에 대한 솔잎 Polyphenols 처리가 Aflatoxin 생성 저해에 미치는 영향

김형열,윤원호,구본순 한국식품저장유통학회(구 한국농산물저장유통학회) 2002 한국식품저장유통학회지 Vol.9 No.1

쌀과 옥수수를 온습도의 조절 없이 상온에서 90일간 장기저장하며 aflatoxin 생성 정도를 측정해 본 결과 쌀과 옥수수에서 공통적으로 저장 30일 이후 각각 0.1, 0.3 ppb의 aflatoxin이 검출되었다. 그러나 저장 온도 및 습도가 상승할수록 aflatoxin 생성 정도는 비례적으로 급속한 증가추세를 나타내어 이들 시료에서 aflatoxin 생성 최적 온습도는 각각 25∼30℃, 80% 내외인 것으로 밝혀졌으며, 동일한 조건하에서 상대적으로 쌀보다는 옥수수에서 그 생성 정도가 심각함을 확인할 수 있었다. 한편, aflatoxin 생성 최적조건인 온도 30℃, 습도 80%의 조건하에서 쌀과 옥수수에 대하여 MeOH 추출물과 polyphenol성 물질들을 각각 0∼0.05% (w/w) 단독처리하여 저장기간에 다른 aflatoxin의 생성량을 측정한 결과는 다음과 같았다. 즉, 전체적으로 그 처리량이 증가할수록 상대적으로 aflatoxin 억제능은 상승하는 것으로 나타났으며, 종류별로는 catechin (CT) < MeOH extract <polyphenol(PP) < flavonoid (FN)의 순으로 나타났다. While rice and corn were stored at room temperature for 90 days the degree of aflatoxin production was measured without humidity and temperature control. The amount of aflatoxin production of rice and corn after 30 days was 0.1 and 0.3 ppb, respectively. The degree of aflatoxin production increased rapidly with increasing storage temperature and humidity. The optimum conditions of aflatoxin production were 25∼30℃ and 80% humidity. The degree of aflatoxin production in corn was higher than in rice under the same conditions. Rice and corn were treated with 0∼0.05%(w/w) of methyl alcohol (MeOH) extract and polyphenol (PP) group materials individualy respectively under the optimum conditions. As the result, the inhibition effect of aflatoxin production increased with increasing the amount of treatment. It appeared as follows: catechin (CT) < MeOH extract < PP < flavonoid (FN).

학기제 현장실습제도의 교육적 가치 분석

김상길,조덕호,이상호,구본급 한밭대학교 생산융합기술연구소 2004 생산기반기술연구소 논문집 Vol.4 No.1

The main purpose of this study forcuses on the analysis of the educational value of the semester-based practicum system by comparing from the 1999 to the 2001 school years. This study is based on questionnaires from the student, faculty members and the industrial personnel who were participated to the practicum. The question is related with the educational value of the program, such as "I think that classroom learning is enriched through the program", "I think that the program is helpful to decide my future job", and so on. The results of the 2001 year program have shown much improvement compared to those of the 1999 and 2000 school years. Especially, many of the negative views students showed in 1999 have turned positive in 2001.