철강산업 근로자들의 자각증상에 의한 피로도 조사

박종안 최신의학사 1981 最新醫學 Vol.24 No.2

볏짚의 혐기성소화시 소화가스 생성에 관한 연구

박종안,허준무,Park, Jong-An,Hur, Joon-Moo 한국환경보건학회 1999 한국환경보건학회지 Vol.25 No.3

Quantity and composition of biogas from semi-continuous anaerobic digestion of straw were obtained experimentally in laboratory scale digesters fed with 1 liter of 5% straw-water mixture and maintained at 35$^{\circ}C$. Experiments were carried out for hydraulic retention time(HRT) of 8, 10 and 15days, respectively. The amount and composition of biogas produced were measured until steady-state was achieved for each run. The amount of biogas and methane percent go through a maximum and decrease continuously towards the steady-state after three times operation of hydraulic retention time(HRT). Methane gas production rates at steady-state increase with the increasing of HRT. Biogas production of 0.45 liter/day with 25% methane, 0.42 liter/day with 33.7% methane and 0.492 liter/day with 31.7% methane were obtained for 8, 10 and 15days of HRT, respectively. The high proportion of soluble carbohydrates present in straw makes the volatile fatty acids to build up within the digester causing a drop in pH that inhibits digestion. Regular control of pH is therefore necessary by adding alkalinity. Reductions in COD increase with increase in HRT. The stratification of plant material within the digester is different from that of manure, and modifications in design and operation of digesters may be necessary if they are fed with plant matter.

집단검진에서 발견된 고혈압증에 관한 역학적연구

홍종관,박종안 순천향대학교 1987 논문집 Vol.10 No.2

This study was made on 28,257 national officers including and private school personnels through the annual physical examination undergone at the SCH Univ. Hosp. in Seoul, Chunan and Gumi from April 1 to July 31, 1986 to figure out any relations between the asymptomatic hypertension found through the physical examination and the variables of physical examination items related with hypertension. The results were as follows : 1. Not only the mean blood pressure of systolic and diastolic but also the prevalence rate of hypertension were increased with higher age in both male and female. 2. The prevalence rate of hypertension was increased with higher Rohrer index in both sexes. 3. The normal group on the tests related with hypertension, i.e. blood sugar, total cholesterol, urine protein, and urine sugar showed the prevalence rate in hypertension, higher than without them. And the tests as serum creatinine, occult blood, and hemoglobin were not related with the prevalence rate of hypertension in both groups. 4. The result of multiple regression analysis on the variables related to hypertension in screening physical examination showed that the variables such as age, body weight, Hb., and Rohrer index were significant with hypertension. 5. The result of multiple regression analysis on 19 variables related to hypertension showed that the variables as age, retinal finding and drinking were significant with systolic pressure, and dizziness and glycosuria were with diastolic pressure in male, while the ECG finding, smoking, edema on extremities, cough, dizziness and glycosuria were significant with systolic pressure, and drinking, fatigur, glycosuria and diet habit were with diastolic pressure in female respectively.

Switching 트란지스터의 最大 電力 減小에 관한 硏究

朴鍾安 조선대학교 동력자원연구소 1979 動力資源硏究所誌 Vol.1 No.1

Several inductors for reducing the peak power of a switching transistor are examined, and a transistor switching circuit using a pararrel combination of a zener diode and an inductor is designed. The zener diode is added to provide a return path for the current in the inductor at turn-off time, and prevent damage to the transistor. It was shown that, for an experimental, the peak power was reduced from 3,905〔w〕to 1.75〔w〕.

첨단산업과 산업단지 조성

박종안 조선대학교 지역사회발전연구원 2003 地域發展硏究 Vol.8 No.1

Industrial crowd and specialization by the regional high technology industrial complex can maximize the synergy effect by economical effect and value chain in a dominant position, support the appropriate industrial environment that the industrial technology development by region technology renovation system construction and the product system of the flexible speciality. There are three common points to be found in the general selecting standards for upbringing high technology industrial business in Gwangju. First the growth motive power of the globe promising high technology industry are, information technology industries, confrontation of industries due to advanced age, global environmental allied industries, and the undeveloped allied industries(such as new materials, mechatronics, space aeronautics, traffic industries, etc). Second, Nation wide promising high technology industry should be; industries based on 5-year plan with industrial technology development, industries based on national vision and development of the strategies, promising industry based on technology. Third, the regionally located industries and the specialized industries such as optical industries. The successful reasons of upbringing high technology industrial are supporting with high qualified human resources, good condition on circulating capital, perfect infra system, developing the consumer market, reliable circulation system, economical network system construction based on renovation, convenient shipping system construction, various tax benefits, neighboring districts civilization, etc. Thus, regional industry accumulating complex upbring the technology renovation high technology industries can increase the industries of international competitiveness, national industrial economic promotion, the consummation of provincial promotion and territorial balanced development, and right to appropriate the government's budget based on the investment plan on concentrated industrial complex. They can strengthen the national competitiveness.

연속 근사형 전하 전달 A/D 변환기

박종안,문용선 조선대학교 동력자원연구소 1987 動力資源硏究所誌 Vol.9 No.1

A new circuit configuration for charge-balancing successive approximation. Analog-to-Digital converter is described. This consists of a improved successive approximation register(SAR) and a weighted capacitor Digital-to-Analog converter (WCDAC). Due to the inherent conversion property of the WCDAC, the A/D converter using the WCDAC can be simply implemented by successive approximation conversion method, and 4 bit monotonicity conversion with differential nonlinearity less 1/2LSB is completed in 80 ㎲.

韓國一部中間都市에 있어서 姙娠損耗의 樣相에 關한 硏究

朴鐘安 서울大學校 保健大學院 1972 公衆保健雜誌 Vol.9 No.1

This study was made to analyze the longitudinal pattern of pregnancy wastage among Korean women with special reference to the residents at middle town, "Echon-Eup" on the basis of fertility survey result which was conducted from March to May 1965(for three months). The fertility data of a sample of 1,012 eligible women who had neither practiced family planning(Except induced abortion) nor experienced abstinence have been utilized for the analysis. Statistical analysis was made on 2,401 pregnancies from 1,012 women aged 40-44 and 1,240 pregnancies from 175 women aged 40-44 who were thought to have almost passed the fecundable period. The followings are the summary of the results: 1. Pregnancy wastage of 1,012 respondents aged 20-44 until the fourth pregnancy order was 3.7%(Still birth; 1.4% Spontaneous abortion; 2.1%, Induced abortion;0.2%)and one of 175 respondents aged 40-44 until the eleventh was 4.8%(Still birth; 1.1%, spontaneous abortion; 2.3%, Induced abortion; 1.5%). 2. Pregnancy wastage of 175 respondents aged 40-44 showed a upward trend as either the pregnancy or deror mother's age at delievery increase. 3. For each pregnancy order, pregnancy wastage appeared more frequent with increment of mother's age at delivery. 4. Pregnancy wastage was found to be 5.4% for the pregnancy occurred within past five years and about 3% for the pregnancy more than five years ago. It seems that there may be some memory bias in the respondent's reportion on the pregnancy wastage. 5. As for the total number of pregnancies experienced by the respondents aged 40-44, 1.7% of them responded as "No experience" and those who experienced more than 6 pregnancies were 80%.

C-C型 Switching素子의 最大電力 減少에 關한 硏究

朴鍾安 朝鮮大學校 動力資源硏究所 1981 動力資源硏究所誌 Vol.3 No.1

Analytical consideration on the surge generation of the typical switching regulator with a two-winding configuration is discussed, and a C-C type transistor switching circuit using a pararrel combination of a zener diode and an inductor is designed. The Zener diode is added to provide a return path for the current in the inductor at turn-off time, and prevent the transistor from damaging. It is shown that the peak rating of the transister can be reduced over 50%.

Gateaux 미분 가능 모름을 갖는 재귀 Bananch 공간에서의 m-accretive 함수의 영점에 관하여

朴鍾安 江原大學校 科學技術硏究所 1984 科學技術硏究 Vol.20 No.1

화학적 발암 물질에 의한 암 발생 기전

김창진,박종안 순천향대학교 1993 논문집 Vol.16 No.2

Cancers have been the leading cause of death since several years ago. The causes of cancer are diverse. and the mechanisms of carcinogenesis are not completely elucidated. The nations in the process of industrial development are suffering from environmental pollutions, which are strong candidate for the causes of cancers. Korea has recently achieved rapid industrial development, and severe environmental pollution, the byproduct of industrialization, became serous hazard to health. Moreover, epidemiological study revealed the increase of incidence of malignant tumors along with industrializations. due to the toxic chemical compounds in pollution. It is not overemphasized to say that we are swimming in the pool of chemical carcinogens. Therefore, it is worthwhile to have the knowledge of chemical carcinogenesis and here we review it with references.