철강산업 근로자들의 자각증상에 의한 피로도 조사

박종안 최신의학사 1981 最新醫學 Vol.24 No.2

2-콘덴서 電荷-傳達 D/A 變換器

朴鍾安 조선대학교 동력자원연구소 1985 動力資源硏究所誌 Vol.7 No.2

Low-cost digtal to-analog (D/A) converters have been developed as simple interfaces to a microprocessor in digital control system, some of which use charge-transfer circuits. In this paper, fators affecting the design of a 2-capacitor, D/A charge-transfer conversion circuit using standard MOS processing are considered analytically, the experimental results from a prototype are presented. This requires theoretically (2n+2) τ conversion time, experimetnally 960 〔㎲〕conversion time for 8 bit processor of 3.579/4 MHz clock cycle. And this requires less die area than the conventional charge-transfer converters, provides inherent monotonicity and differential linearity. The converter has been found to be immune to variations in temperature, time, and process.

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%.

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.

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〕.

고분해능 다단 WCDAC 설계에 관한 연구

박종안,문용선 조선대학교 동력자원연구소 1986 動力資源硏究所誌 Vol.8 No.2

Binary weighted capacitor digital-to-analog converters (WCDAC) based on charge redistribution suffer from the disadvantage that they require N-bit ratio-accurate capacitor array to achieve N-bit monotonic conversion. That is, as the number of bits increases, the matching requirement on the capacitor array becomes tighter. In this paper a new WCDAC is described which uses multistage capacitor arrays in order to reduce the capacitor mismatch. This technigue combines multistage capacitor arrays with each reference voltage. For experimental 9-bit conversion 2²C(pF) MSB capacitor in the multis tage (3 stage) WCDAC. is used campared with2^8C(pF) MSB capacitor in one stage WCDAC. And the total capacitance of the multistage WCDAC is 3 * 2³C(pF) while that of the one stage WCDAC is 2^9C(pF). Therefore it is possible to reduce the mismatch as well as the total die size for LSI design.

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.

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

아산시 종량제 쓰레기 봉투에 배출된 생활폐기물 성상의 주택유형 및 계절적 특성

박종안,한성현,손부순,이종화,장봉기,염윤기 순천향대학교 기초과학연구소 2002 순천향자연과학연구 논문집 Vol.8 No.2

This study was investigated physicochemical characteristics of residential wastes in using volume-base charge system of disposal bag. It examined from August 31, 1999 to March 30, 2000 to Asan city. It divided residing conformation to singleness house, few stories apartment (below 5 layers), high-rise apartment (more than 6 layers). Samples were collected 20ℓ volume bag by each 3 volume-base charge system of disposal 1 times by season in total 27 areas. Total 108 samples were analyzed characteristics of living wastes and three ingredients (moisture, volatile solids, ash) by season and house types. 1. Mean bulky density in the volume-base charge system of disposal envelope showed by 0.206 tons/㎥. Bulky density in high-rise apartment was the lowest by 0.183 tons/㎥ by house types, and few stories apartment and singleness house appeared similarly by each 0.217 tons/㎥, 0.218 tons/㎥. 2. Weight by season of waste in volume-base charge system of disposal bag was the highest in winter and the lowest in spring. 3. Occurrence amount by composition ratio about total weight combustibility was 93.3%, and incombustibility was 2.8%, and recycling was 4.0%. In physical composition, the compositional weight fraction was food, 47.9%, paper, 27.8%, vinyl & plastics, 10.7%, textile 3.4%. 4. In combustible wastes, the compositional weight fraction was food, 51.3%, paper, 29.8%, vinyl & plastics, 11.4%, textile, 3.7%, In combustible wastes, the compositional weight fraction was glass & ceramics, 85.3%, and soil & others, 9.1%, and metal was 5.6%. Glass bottles of recycling were 36.8%, plastics kind 24.6%, and can kind was 3.8%. 5. Average moisture content of combustible wastes appeared 28.60±22.35% and moisture content of food kind highest by 45.29%. Ash content was few amount of 6.55%. Volatile solids amount was high by 64.84% but vinyl & plastics was the highest by 78.05%, and food was the lowest by 46.83%. 6. Three ingredient findings moisture contents by season of combustible waste were the highest in summer and the lowest in winter (p<0.01).