기상으로 존재하는 유독성유기용매의 완전산화 메커니즘

홍인권,이승범 단국대학교 1999 산업기술연구 Vol.1 No.-

The deep oxidation mechanism of gaseous toxic organic solvents was studied on a Pt / γ-Al_2O_3 catalyst phase at temperature ranging from 200 to 350℃. An approach based on the Mars-van Krevelen rate model was used to correlate the results. The objective of this study was to depict the kinetic behavior of the platinum catalyst for deep oxidation of VOCs. The conversions of VOCs were increased as the inlet concentration was decreased and the reaction temperature was increased. The maximum deep conversion of MEK, benzene and toluene were 91.81%, 75.45% and 55.69% at 350℃, respectively. The k_3 constant increases with temperature faster than K_1 the constant, that is, the surface concentration of (VOCs…O) is higher than that of (O) at higher temperature according to the Mars-van Krevelen mechanism. Also, the oxidation activation energy of toluene was larger than MEK for toluene is aromatic compound which have stronger bonding energy. Therefore, the catalytic oxidation mechanism of VOCs with Mars-van Krevelen could be used as the basic data for industrial oxidation processes.

재해성 요추 추간판 탈출증의 역학 및 임상적 연구 : 비재해성 추간판 탈출증과 비교분석

권순용,이승구,장일석,김지홍,임영 대한산업의학회 2000 대한직업환경의학회지 Vol.12 No.2

Objectives : The purpose of study was to define the clinical and epidemiological factors of HNP and to provide the meaningful sources for establishing a prognosis and a rationale for clinical management of occupational low back problem. Methods : This study was performed at eight branch hospitals of Catholic University of Korea and several governmental hospitals for occupational disorders around the Kyunggi province of Korea since Jan. 1985. We analyzed the several factors about lumbar HNP through comparative study of the hospital admission series of each 200 patients in both occupation- and nonoccupation related, subjected to epidemiologic and clinical investigation, respectively. Results : 1. Mean age of occupational HNP was younger (30.9±8.8) than non-occupational HNP (35.2±10.5) (p〈0.05). 2. The duration of clinical symptom before admission was longer in non-occupational HNP(19.9±22.8 Mo.) than in occupational HNP(6.9±12.4 Mo.) (p〈0.05). 3. The symptomatic attack before admission was more frequent in non-occupational HNP(3.7±1.9) than in occupational HNP(2.5±0.9) (p(0.05) 4. There were no significant differences in physical findings between two groups, except for low rate (63%) of straight leg raising test (SLR) limitation in occupational HNP compared to non-occupational HNP(83%) (p〈0.05). 5. Even though The main reason for operative intervention was a failure of conservative treatment in both groups (p〈0.05), extruded subligamentous type was predominant(50%) in occupational HNP (p〈0.05), whereas extruded transligamentous type occupied major portion (67.8%) in non-occupational HNP (p〈0.05). Conclusion : The clinical results were poor in occupational HNP in both conservative and operative management groups, compared to non-occupational HNP (p〈0.05) and mean durations admission and re-admission rate was higher in occupational HNP, compared to non-occupational HNP (p〈0.05).

압력이 가해진 반응공정에서 BTX의 촉매산화 전환특성

홍인권,이승범 단국대학교 2000 論文集 Vol.35 No.-

Catalytic oxidation of benzene, toluene, and m-xylene (BTX) was carried out in high pressure tubular reactor packed with 0.5% Pt/γ-Al_2O_3 catalyst. The conversions of BTX were increased as the inlet concentration was decreased and the reaction temperature and the molar density of oxygen were increased. And the molar density of oxygen was increased with pressure. The maximum deep conversion of benzene, toluene and m-xylene were 92.1%, 66.0% and 57.5% at 350℃ and 136 atm, respectively. In this study, the many intermediates produced by the partial oxidation of BTX was detected from off-line samples.

전자공학교육과 실험교과내용에 관한 연구

홍봉식,김태균,오승엽,김환우,권오석 충남대학교 공업교육연구소 1983 論文集 Vol.6 No.2(A)

The currenty offered experiment courses are completely reconsidered and reconfigured. The whole subjects are divided into 10 seperate courses, each of which should represent either basic or advanced stages of differing fields of the electronic engineering. It has been aimed that the courses form an elaborate hierachy so that they are minimally redundant but linked to one another in their fringes. Also, it has been pursued that the new courses should not fall obsolete in at last next five years exploring the maximum possibilities of the currently available equipments.

강인한 퍼지 디지털 PI+D 제어 시스템의 설계 및 구현

권태익,이재홍,김승철,설재훈,임영도 동아대학교 정보기술연구소 2001 情報通信硏究所論文誌 Vol.9 No.1

In this paper, Fuzzy Digital PI+D Controller plans for load, noise, plant change, Fuzzy Controller makes use of simple four rule and membership function, and plant used three phase Induction Motor. Characteristic of system compared from experimentation respectively the proposed Control System, Digital PID Control and Digital PI+D Control System.

동아의 체중조절 효과

홍석산,이승환,김철용,권석형,황보식 한국식품영양학회 2002 韓國食品營養學會誌 Vol.15 No.4

본 연구에서 선발된 17종의 천연물을 Sprague- Dawley rat에 급여한 결과, 체중 증가, 에너지 소비, fat pads 중량, 간의 triglyceride 함량, atherogenic index 그리고 혈중 글루코오스의 함량 등이 감소하는 경향을 나타내었다. 특히 동아를 구강으로 섭취시킨 결과, 체중 증가, 에너지 소비, fat pads 중량, 그리고 혈중 글로코오스의 함량등이 감소하였으나, 간의 triglyceride 함량은 오디와 송엽의 열수 추출물보다 적게 감소하였다. 동아, 오디, 그리고 송엽을 혼합하여 사용한 결과, 각각의 원료를 사용할 경우보다 비만이 개선되는 것으로 나타났다. This study attempted to evaluate the effectiveness of function of Wax Gourd for obesity and the related disease of adult people can be developed by the combination of the 17 food materials screened in this study. The experiments using Sprague-Dawley male rats show that seventeen kinds of food material inhibited the increase of body weight gain, energy intake, fat pads weight, liver triglycerides content, atherogenic index, and blood glucose concentration induced by cafeteria diet. Oral administration of wax gourd decreased most body weight gain, energy intake, fat pads weight, and blood glucose concentration induced by cafeteria diet. Oral administration of wax gourd decreased most body weight gain, energy intake, fat pads weight, and blood glucose concentration. Liver triglycerides content was the lowest in the group administered mulberry stem extract and the group administered pine leaves showed the lowest atherogenic index. The combined administration of wax gourd, mulberry stem extract and pine leaves improved more the obesity and related symptoms than the individual administrations.

대용량 어휘를 기반으로 한 화자의 적용 알고리즘

홍승준,권영헌,이건상 한양대학교 이학기술연구소 2001 이학기술연구지 Vol.3 No.-

화자독립인식기의 평균적인 성능은 좋더라도 사용하는 화자에 따라 인식률이 많이 차이가 난다. 이러한 문제점을 해결하기 위한 방법으로 본 논문에서는 기존의 codebook을 사용하여 사용자의 적은 어휘로써 높은 인식률을 가질 수 있는 화자 적응 방법을 제안한다. 본 논문에서는 대용량 어휘인식을 위해 음소인식에 뛰어난 성능을 지닌 CHMM(continuous hidden Markov model)을 사용하였고, 적응 알고리즘인 MAP(maximum a posterior)를 사용하여 HMM의 파라미터를 적응시키는 방법으로 대용량 어휘 인식률을 계산하였다. 화자 적응 알고리즘을 적용하기 이전과 화자 적응 알고리즘을 적용했을 때 인식률을 비교하였을 경우 음소 인식률이 40%이상 좋아짐을 알 수 있었다. In this paper. we propose a speaker adaptation algorithm. We make an experiment using CHMM which shows good performance for phoneme recognition. MAP formulation is developed to adapt the characteristics of speaker with the estimation of the HMM parameter from the training data. The proposed adaptation algorithm is evaluated in large vocabulary continuous speech recognition. In the experiment. we compare the recognition accuracy of the adapting acoustic model with that of common speaker. At the experimental results. MAP algorithm achieve up to about 40% additional reduction of error in phoneme recognition.

자동차 공조용 핀형 열교환기의 성능특성에 관한 연구

홍경한,전상신,이승재,박찬수,권일욱,김재열,김병철,하옥남 한국공작기계학회 2004 한국생산제조학회지 Vol.13 No.4

Fin-tube type(Fin-type) heat exchanger has been tested in order to replace the heat exchanger of parallel flow type(P.F-type) which is now widly used in automobile air conditioning system. The following conclusions are drawn by the comparison of the characteristics of the heat exchangers. Evaporator and condenser capacities and COP(Coefficience of performance) were varied as with the compressor speed, outdoor air temperature and air flow rate changed, which much influenced on the characteristics of the air conditioning system. Evaporator and condenser capacities were increased with increasing compressor speed and outdoor air temperature. Evaporator and condenser pressures of Fin- type were decreased by 7% and 5% respectively compared with those of P.F-type. The COP of Fin-type was decreased with increasing outdoor air temperature and compressor speed. The COP of P.F-type was decreased by 14% compared with that of Fin-type.

0.412 MeV 감마선에 대한 원주형 NaI(Tl) 섬광체의 총 절대검출효율 계산

홍권표,신희성,이상윤,노성기 대한방사선 방어학회 2002 방사선방어학회지 Vol.27 No.4

Total absolute detection efficiencies of a 7.62 cm(dia.) and 7.62 cm(height) cylindrical NaI(Tl) crystal have been calculated for 0.412 MeV r -rays from a source(point, circular disk, square and line type). In this calculation the linear energy-absorption coefficients based on Hubbell's data have been considered and then calculated total absolute detection efficiencies compared with those from Grosjean and Bossaert. Besides, the source axis-to-detector axis shift distance which, could give rise to about 0.05% deviation in the total absolute detection efficiencies has been calculated for a line-type source of 0.5 cm in its length when a source-to-detector distance is 5 cm. It is revealed that the total absolute detection efficiencies obtained in this study are considerably different from those of Grosjean and Bossaert. In addition it is found that the deviation induced due to an imperfect center of a line type source may be within 0.05% if the shifted discrepancy is no larger than 1.74mm.

정신병적 증상이 동반된 기면병 1예

홍승철,송정민,정종현,권용실,한진희,이성필 大韓神經精神醫學會 2003 신경정신의학 Vol.42 No.5

Narcolepsy is a sleep disorder characterized by excessive daytime sleepiness, cataplexy, sleep paralysis, hypnagogic hallucinations and disrupted nocturnal sleep. We report a patient with a diagnosis of schizophrenia who was subsequently diagnosed as narcolepsy. A case of a 22-year-old woman with concomitant narcolepsy and psychotic symptoms was discussed from a perspective of the diagnosis and therapeutic challenges, particularly on pharmcological treatment dealing with issues raised by their coexistence.