敎科學의 性格과 敎師의 專門性 : 세계화, 정보화의 시대에 임하여

李敦熙 忠北大學校 敎育·生活硏究所 1998 한국교육논총 Vol.- No.1

가스흡착력의 원리에 의한 CS₂의 활성탄관 파과현상에 미치는 시료채취속도의 영향

李鎭憲,洪仁錫,韓敦熙 인제대학교 1994 仁濟論叢 Vol.10 No.2

The purpose of this study was to determined the effects of flow rates on breakthrough in charcoal tubes. Firstly the charcoal tubes were contaminated with CS2, and then the effects of them were examinated by using the principle of Gas Adsorption Kinetics. The results obtained were as follows. 1) As the flow rates were increased, k'-values were increased, τ-values were decreased, and k'-values were constant as 3.527±0.558. 2) 10% breakthrough times of 0.05, 0.1 and 0.2LPM were 149, 90 and 34 min, respectively. 3) As the probability of breakthrough were increased, the effects of sampling flow rate against the breakthrough time were proportionally increased.

방사성 동위체 도입과 그 추적기술에 의한 수도계(水稻系) 활성상의 해명과 개선에 관한 연구(제3보) : 저인산성 무기 용성물질의 시용과 용수조절 효과에 대하여 Effects of Application of Fused Magnesium Low Level Phosphate and Control of Irrigation Water

이춘영,안학수,정희돈,김규원,노준정 한국농화학회 1973 Applied Biological Chemistry (Appl Biol Chem) Vol.16 No.1

1. Through out the entire stage of growth, the amount of nutrients, number of tillers and of spikes increased in the Simagcalin treated plot as compared with the control. The treated plot showed healthul growth at the later growing stage. On the other hand. management of irrigation water resulted in raised the grain straw ratio and retarded the culm height about 10%. 2. Application of Simagcalin greatly increased the content of phosphorus and magnesium at the harvesting time. The culm and sheath analyses are recommendable for the determination of magnesium deficiency. 3. The controled irrigation would effect root activity as the main factor, and Simagcalin might act as a secondary factor. 4. While the application of phosphorus may not affect the yield components, The basic elements in Simagcalin may enhance the uptake ov nutrients under heavy application of nitrogn.

胃癌組織에 出現하는 비반세포의 數的變化 關한硏究

李敦熙,金世民 고려대학교 의과대학 1984 고려대 의대 잡지 Vol.21 No.1

There are various opinions regarding actions of mast cell in malignant tumor from enhanced host defense mechanism for cancer to no actions at all for cancer. There are even a theory that mast cell has actually actions to promote malignant tumor growth. This author had carried out this study in order to find out any relationship between mast cell and various gastric conditions, such as chronic superficial gastritis, chronic peptic ulcer, mucosal dysplasia, well differentiated adenocarcinoma, pooly differentiated adenocarcinoma and malignant lymphoma. The results obtained are as follows: 1. In the gastric mucosal layer, the numbers of mast cells are rare; exhibiting 0-5/20 HPF in chronic superficial gastritis, 5-13/20 HPF in chronic peptic ulcer, and 0/20 HPF in malignant diseases. 2. In the submucosal layer, the numbers of mast cells were greatly increased in chronic superficial gastritis and chronic peptic ulcer. The numbers of mast cells were moderately increased in gastric mucosal dysplasia and markedly decreased in adenocarcinoma and malignant lymphoma. 3. In the muscle layer, mast cells were seen in the only intermuscular connective tissue and markedly increased in chronic peptic ulcer. The mast cells were moderately increased in mucosal dysplasia and poorly differentiated adenocarcinoma. In malignant lymphoma, the mast cells were slightly decreased and in other cases, there was no changes of mast cells. 4. In cases of adenocarcinoma, the mast cells were not seen in the lesions, which were in the mucosal, in the submucosal or in the muscle layer. We can conclude with the above result that the change in the number of mast cells especially at the submucosa is related to the degree of differentiation of cancer cell.

교육관의 변화와 과제

이돈희 서울대학교 사회과학연구소 1985 社會科學과政策硏究 Vol.7 No.3

8개 압저항 브릿지구조를 이용한 저 타축 감도 실리콘 가속도센서

徐熙敦,李榮泰,崔世崑 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

A low off-axis sensitivity piezoresistive accelerometer has been presented. The off-axis sensitivity was reduced by arrangement of eight piezoresistors on two the beams. The structure and stress distribution of the accelerometer was optimized using FEM(finite element modeling) simulation. The dependence of sensitivity and resonance frequency were also simulated as a function of the beam length for a constant overall size(2000μm). Accurate thickness control of the beams was realized by the etch-stop techonology using SDB(silicon direct bonding) wafer SiO_(2) layer and RIE(reative ion etching) method. This method is relatively simple and very useful for fabrication of accelerometer.

인버터 구동용 유도전동기 고정자 권선의 절연특성 연구

황돈하,김동희,이광식,정원영,김영훈,오승훈 영남대학교 공업기술연구소 1999 工業技術硏究所論文集 Vol.27 No.2

Inverters with high speed switching and advanced PWM techniques are widely used for variable speed applications. But some adverse effects on the stator winding insulation are reported due to excessive voltage stress, which results in the premature insulation breakdown. This is aggravated by the high switching speed of modem switching devices such as IGBT (Insulated Gate Bi-polar Transistor) with which the rate of rise in voltage (dv/dt) increases considerably. In this paper, the test results for evaluation on the stator winding insulation of 310V induction motors are presented. Also, the insulation characteristics are presented in order to analyze the insulation strength under high voltage due to high switching speed of IGBT PWM inverter. 26 induction motors of 6 types with different wires and insulation techniques are built and thoroughly tested. The maximum partial discharge (PD) magnitude (Qm) and the discharge inception voltage (DIV) are obtained by PD test. Under AC current test, the rate of change in AC current (ΔI) and the change in dissipation factor (Δtanδ) are measured. From the above test data, the effects due to different wires and insulation techniques on the insulation characteristics of low-voltage induction motors are compared and analyzed. The insulation technique to enhance the insulation strength is suggested from the test results.

생체신호 처리용 ASIC 칩 개발

서희돈,이준하 경북대학교 센서기술연구소 1997 연차보고서 Vol.1997 No.-

일괄공정 압저항혈 압력센서의 특성

서희돈,이동원,손미정,최세곤 嶺南大學校 工業技術硏究所 1998 工業技術硏究所論文集 Vol.26 No.1

This paper describes structural characteristics of three kinds of piezoresistive pressure sensors, which include wheatstone-bridge type, center-boss type and single-element type, fabricated on one-chip by batch process. In order to optimize device dimensions with respect to the desired characteristics, analytical formula and finited-element modeling(FEM) are used in design process. In experiments the pressure sensitivity of wheatstone-bridge type is about 2.2㎷/V·㎪. The fabricated center-boss pressure sensor has improved in the characteristics as linearity at low pressure, and sensitivity is about 2.415㎷/V·㎪. In single-element type with a four-terminal gauge using shear stress, the maximum sensitivity about 0.4㎷/V·㎪ appeared at the center of the diaphragm with the 3:1 of the length : width ratio. this type is very appropriate method to minimize the temperature dependance of the offset voltage and sensitivity, because the fabricated sensors reduce the offset of themal stress and mismatch of piezoresistros as compared with the wheatstone-bridge type.

인간 면역부전 바이러스(HIV) 감염자 사이에서의 1기 및 2기 매독의 유행

장희창,조재현,박완범,이기덕,이창섭,김홍빈,오명돈,최강원 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

목적 : 국내 HIV 감염자 사이에서 발생한 매독의 유행을 보고하고, 그 역학적 특성을 규명하고자 하였다. 재료 및 방법 : 1999년 7월부터 2003년 9월까지 서울대학교 병원에서 추적 관찰을 받아온 HIV 감염자를 대상으로 하여 1기 및 2기 매독의 발생을 조사하였다. 발생률을 정확히 구하기 위해 추적 관찰을 받은 모든 HIV 감염자의 인년을 6개월 간격으로 구하였다. 결과 : 51개월 동안, 465명의 HIV 감염자가 서울대학교 병원에서 추적 관찰을 받았다. 이중 38명이 1기 및 2기 매독으로 진단되었다. 1기 및 2기 매독의 발생률은 이기간 동안 100인년 당 4.1명이었다. 1999년 7월부터 2001년 12월 사이에는 발생자가 없었으나, 이후 발생률은 꾸준히 증가하여 2003년 9월에는 100인년 당 18.8명이 되었다. 1기 및 2기 매독의 발생률은 동성애자 및 양성애자에서 이성애자에서보다 4.3배 높았고, HAART로 치료를 받지 않은 환자에서 HAART로 치료를 받고 있던 환자에서 보다 10.9배 높았다. 결론 : 2002년부터 국내 HIV 감염자 사이에서 1기 및 2기 매독이 유행하기 시작하였고, 이러한 유행은 동성애자와 양성애자 및 HAART로 치료를 받고 있지 않던 사람 사이에서 발생하였다. Background : This study was performed to characterize the epidemiologic and clinical features of outbreak of syphilis among HIV sero-positive patients in Korea. Materials and Methods : A retrospective case review of patients diagnosed with primary and secondary syphilis from July 1999 to September 2003 was carried out at Seoul National University Hospital in Korea. To estimate the incidence, person-years (PYs) of all HIV sero-positive patients, who visited the hospital in the same period, were calculated every 6 months. Results : In a 51 month period, 465 HIV-positive patients were followed up at Seoul National University Hospital. 38 cases of primary and secondary syphilis were diagnosed. The incidence of primary and secondary syphilis was 4.1 per 100 PYs during the study period. There was no case from July 1999 to December 2001, and then the incidence rose until September 2003 from 5.5 per 100 PYs in 1999 to 18.8 per 100 PYs in 2003. The rate of primary and secondary syphilis was 4.3 times higher among homosexual and bisexual men than heterosexual men (95% CI 1.87 to 11.17), and 10.9 times higher among patients who did not receive HAART than patients who were receiving HAART (95% CI 5.47 to 21.79). Conclusion : The outbreak of primary and secondary syphilis among HIV-positive patients started in 2002 and has been escalating, especially among homosexual/bisexual men and in patients who did not receive HAART.