고분자 감습막의 합성 및 감습 특성

공명선,조현기 단국대학교 신소재기술연구소 1991 신소재 Vol.1 No.-

고분자막 습도 센서의 감습 재료를 합성하기 위하여 4-chloromethyl styrene(4-CMSt)과 methylmethacrylate(MMA)의 여러 가지 조성의 공중합체를 합성하여, 이를 전극에 도포하고 N, N, N', N'-tetramethyl ethylene diamine으로 4차 암모늄화 시켰다. 상대 습도에 따른 impedance 변화를 측정한 결과, 공중합체에서 MMA의 비율이 많아지면서 impedance가 감소하였으며, 폴리 비닐 알콜을 첨가하면 impedance가 증가하였다. 또한 4CMst/MMA=1, 경우 hysteresis는 ±5% RH 내외이며, 온도 의존계수는 -0.5% RH/℃이었다. 30% RH, 60% RH, 90% RH에서의 평균 저항 값은 각각 3.0×10^6Ω, 200KΩ 9KΩ이었다. The various composition of copolymers of 4-chloromethyl styrene(4-CMS5) and methyl methacrylate(MMA) were synthesized as a humidity sensitive meterial and quartenized N, N, N', N'-tetramethylethylene diamine(TMED). Impedance versus relative humidity decreased as the content of MMA in the copolymer increased. Addition of polyvinyl alcohol increased the impedance of the humidity sensor. In the case of 4-CMSt/MMA=1, the hysteresis and temperature coefficient were ±5% RH and -0.5% RH/℃. The average resistance at 30% RH, 60% RH and 90% RH are 3.0×10^6Ω, 200KΩ and 9KΩ respectively.

근로자의 보건교육 요구도에 영향을 미치는 요인에 관한 연구

공득희,이명선 韓國保健敎育學會 1994 보건교육건강증진학회지 Vol.11 No.1

Health Education is very important not only in school or community fields but also in industrial fields. And health education is most fundamental and enthusiastic area in industrial health. The purpose of this study was to analyze the workers' health education needs and the factors which could affect them. The subjects for this study was 855 workers selected from 57 factories in Inchon. The results were as follows : 1. For demographic variables, sex, age, educational level, and income of the workers were investigated. Most of the workers were males (80.2%). Of the respondents, 30~39 years old were 41.3%. Approximately 62% of the workers were high school graduates. In additions, those who reported they earned 500,000~800,000 won monthly were 41.9%. 2. Behavioral characteristics of the workers investigated in this study included smoking, drinking and physical activities. Of the respondents, 55.9% were smoking cigarettes, and 26.8% of the workers reported they drank alcohol once or twice a week. The workers who were taking any form of exercise regularly were 31.6%. 3. Occupational characteristics of the workers included working period working hours a day, medical examination, and so on. About 37.6% of the workers had worked 1~5 years and 53.6% of the respondents were working less than 8 hours a day. More than half of the workers in this study were taking special medical examination(59.3%) and 59.6% of the respondents were working at the production line in the factories. And most of the respondents (69.0%) were mere members of the staffs. 4. For perceived health status of the respondents, 41.1% answered they were healthy. And for the level of heath status, health grade 20.4% of the workers were unhealthy. 5. Health education areas the workers in this study wanted to learn were as follows : 1) Mental health 2) Worksite environment 3) Safety control 4) Disease control. 6. Those who reported having ever received health education in the factories were 20.9%. 7. Women had more health education needs in personal health care, disease control and family health areas than men. Each age group had different health education needs in all health areas and the differences were significant statistically. 8. The workers who had received special medical examination had more health education needs in worksite environment, safety control, and disease control areas than those who had received general medical examination. The lower the satisfaction of the work and the working environment was, the higher the health education needs of worksite environment area were. 9. For the levels of health status healthy workers were more likely than unhealthy workers to have health education needs in all health areas.

Randon Threshold를 가진 부품의 정기 검사하에서 최적 교환 정책

공명복 울산대학교 1990 연구논문집 Vol.21 No.1

부품은 시감에 따라 연속적으로 마모되어 마모가 Rendom Threshold를 능가하면 고장을 일으킨다. 부품은 정기적으로 행하는 검사 시점에서 어떤 마모 수준을 넘으면 예방 교환된다. 고장나면 즉시 교환된다. 단위 시간당 평균 비용을 최소화하는 최적 교환 수준을 유도하였다. 고장 밀도 함수가 Logarithmically Convex Density인 경우 예방 교환을 하지 않는 것이 최적 정책이다. An item fails when it wears continuously on time beyond a random threshold. The item is preventively replaced if the wear at periodic inspections exceeds a certain wear level. Upon failure, it is replaced immediately. The optimal wear level for preventive replacement which minimiges the long-run average cost per unit of time is derived. In case of logarithmically convex density of failure, no preventive replacement policy is optimal.

외상성 고관절 아탈구의 원인과 치료 : 2 Cases Report

문명상,옥인영,염공섭 최신의학사 1980 最新醫學 Vol.23 No.9

암모니아성 질소(NH_4^+-N)제거를 위한 제올라이트성 물질의 제조

류태공,류재춘,한명식,김철규,김영호,양현수 忠南大學校 産業技術硏究所 2002 산업기술연구논문집 Vol.17 No.2

The objectives of this study were to synthesize high ion-exchangeable zeolitic materials prepared from coal fly ash and to determine the adsorption capacities for the removal of NH_4^+4-N in wastewater For comparison. NH_4^+-N adsorption capacities of commercial, natural, and synthetic(4A type, Si0_2/Al_2O_3=1.98. Na_2O/SiO_2=1.54. H_2O/Na_2O=46.95) zeolites were investigated at the same condition. Zeolitic materials were prepared from coal fly ash by hydrothermal reaction with various NaOH concentrations at the reaction time of 4h and the reaction temperature of 100℃. It showed that the zeolitic material prepared at a 4M-NaOH concentration had the most NH_4^+-N adsorption capacity. Theremoval efficiency of NH_4^+-N on the zeolitic material was little difference compared with those on natural and commercial zeolites, though it was lower than that on a synthetic zeolite(4A type). As a result, it is expected that the prepared zeolitic material could be applicable to adsorbent for the NH_4^+-N removal in wastewater.

일제의 조선인 강제징발 실상

허종호,리철홍,공명성 한국역사연구회 2003 역사와 현실 Vol.- No.50

This paper surveys the scale and characteristic of the forced arrestment of Koreans by Japanese Imperialist and would call Japan's responsibility for it. Japan's reparation for the forced arrestment of Koreans is the national obligation. It is because the forced mobilization of Koreans was intended and directed by Japan authority and was the national criminal act accomplished under the national direct control. After Sino-Japanese war in 1937, Japanese Imperialist commandeered Koreans with the several form as "compulsory service", "emigration", "collection", "commandeering" and its number was reached as many as 84 hundreds thousand. Characteristic of the forced mobilization by Japanese Imperialist was accompanied by the form of policy to obliterate the Korean nation regardless of regions and social classes. Therefore, Japan's apology and reparation ought to be an unavoidable obligation.

폴록사머 및 프로필렌글리콜을 이용한 클로트리마졸 고형 좌제의 물리화학적 특성

현경희,오유경,김정애,공경환,김지현,양준호,배명수,김호동,이종달,장현욱,용철순,최한곤 한국약제학회 2005 Journal of Pharmaceutical Investigation Vol.35 No.2

To develop a clotrimazole-loaded solid suppository with poloxamer and propylene glycol, the melting points of various formulations composed of poloxamer 188 (P 188) and propylene glycol were investigated. The dissolution study of clotrimazole delivered by the suppository composed of P 188 and propylene glycol was performed. The mixtures composed of P 188 and propylene glycol were homogeneous. Propylene glycol affected the melting points of poloxamer mixtures. In particular, the mixture [P 188/propylene glycol (70/30%)] with the melting point of about 32°C was a solid form at room temperature and instantly melted at physiological temperature. Furthermore, propylene glycol affected greatly the dissolution rates of clotrimazole from the suppository. Dissolution mechanism analysis showed the dissolution of clotrimazole was proportional to the time. Our results indicated that the solid suppository with P 188 and propylene glycol would be a candidate of rectal dosage form for clotrimazole.

The Effect of Round Flow Path Discharger and Back Panel Open Ratio on a Performance of Open Refrigerating Showcase

Myung Keun Gong,Gun Woo Kim,오명도 대한설비공학회 2019 International Journal of Air-Conditioning and Refr Vol.27 No.3

Numerical study is conducted to confirm the effect of round flow path control and back panel open ratio on a performance of open refrigerating showcase in this study. The rounding control is applied to flow path of air discharger in various radii and the punched panel with various open ratios is applied to back panel of showcase. These structural changes have a significant impact on its aircurtain performance because both changes can affect flow pattern of showcase. To prove it, the two-dimensional steady simulation is performed using k k –ε ε turbulent model. The performance of showcase is assessed using entrainment factor which is a ratio between cooled air and ambient air at the suction of refrigerating part. As a result of simulation, the curved path at air discharger reduces the entrainment factor by a maximum 9% less than typical design. The curved flow path removes the dead zone at the honeycomb structure of discharger. In addition, it is found that there is an optimal back panel open ratio at the storage space of the showcase. When the back panel open ratio is 0%, the cooled air from the discharge is attached to the cold storage area because of the Cowanda effect. However, the Cowanda effect is eliminated when back panel open ratio increases. Results address that the entrainment factor remains almost the same at back panel open ratio 3.93% or more. Lastly, the simulation of showcase with product in cold storage area is conducted to confirm the structure changes effect on performance of real use showcase according to KS Standard.

Comparison of Soil Testing Methods for Plant Available Phosphate

Myung Sook Kim,Han Kang Kwak,Yoo Hak Kim,Seong Soo Kang,Myung Suk Gong,Yong Seon Zhang,Hong Bae Yoon,Chang Hoon Lee 한국토양비료학회 2013 한국토양비료학회지 Vol.46 No.3

Most test methods for plant available soil phosphate are based on the extraction with a chemical solution. The objective of this study is to evaluate available phosphate of various tests at different soil phosphate levels. Two experiments were conducted as follows: i) Extracting capacities of soil phosphate tests - Mehlich III, Mehlich II, Bray I, Olsen, Kelowna, and Modified Lancaster(Mod. Lancaster) - were compared with that of Lancaster test for the soils collected from 32 paddy and 27 upland fields with various soil chemical properties. ii) Field trials on comparing to phosphate uptake by plant were accomplished by cultivating rice and corn plants in the pots filled with the soils. Available phosphate of Lancaster test was significantly correlated with those of Mehlich III, Mehlich II, Bray I, Olsen, Kelowna, and Mod. Lancaster. In upland soils, available phosphates of all the tests were curvilinearly regressed with phosphate uptake by corn. The determination coefficients (R²) of the regression equation between available phosphate in soils and phosphate uptake by plants were ranged from 0.861 (Mehlich III) to 0.741 (Olsen). In paddy soils, the available phosphate measured by Mehlich III and Lancaster was significantly correlated with phosphate uptake by rice. In conclusion, Lancaster and Mehlich III tests could be used for predicting available phosphate in upland and paddy soils.

T-S fuzzy 모델을 이용한 비선형 시스템의 tracking 제어에 관한 연구

손명공(Myung-Gong Shon),성동한(DongHan Seong),손천돈(Cheon Don Son),정은태(Eun Tae Jeung),권성하(Sung-Ha Kwon) 대한전기학회 2006 대한전기학회 학술대회 논문집 Vol.2006 No.10

This paper deals with a tracking problem for nonlinear systems using its T-S fuzzy model and internal model. We extend the internal model of linear systems to an internal model of T-S fuzzy systems to accompany with state error of zero. A sufficient condition of the existence of a tracking controller for T-S fuzzy systems is expressed by linear matrix inequalities. A system of inverted pendulum on cart is illustrated to verify our method.