철강산업 근로자들의 자각증상에 의한 피로도 조사

박종안 최신의학사 1981 最新醫學 Vol.24 No.2

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%.

低溫灰化法에 의한 중금속 분석

박종안 순천향대학교 1986 논문집 Vol.9 No.2

This research was conducted to investigate the optimal conditions of low temperature ashing apparatus, modified electric furnace, to solve the difficult problems frequently occurring in the analysis of heavy metals in various samples. The results were as follows: 1. Analyzed values of the samples pre-treated by low temperature ashing apparatus obtained more accurate results than those obtained by wet analytical method. The coefficient of variation of analyzed values were 2.7% by low temperature ashing method and 7.4% by wet analytical method. 2. The optimal electric power(W) was 200-300 and oxygen flow rate(ml/min) was about one-third of each maximum electric power in values. 3. Ashing time was shortest at the optimal conditions and it took longer with the increased amount of samples. 4. Low temperature ashing method gave better recovery yield rate for Cd, Cu, Pb or Zn than muffle furnace ashing method. Muffle furnace ashing method using high temperature of 550℃ gave the yield as low as below 50% for Zn, Pb or Cd. It was suggested that the latter be not adequate for analysis of Zn, Pb or Cd, in the samples.

아산시의 환경보전을 위한 수질(하천 및 호소)오염 실태조사 및 대책

이종화,박종안 순천향대학교 기초과학연구소 1996 순천향자연과학연구 논문집 Vol.2 No.1

The object of this study is to survey water quality of river and reservoirs in Asan city. We also suggest some alternatives for environmental preservation toward sustainable urban development of Asan city. This study analyzes water quality(pH, DO, BOD, COD, SS, Pb, Cd, T-P and T-N) of river and reservoirs. First, the level of water quality of Kodyke river is in the range of level Ⅱ-Ⅲ lower than the level Ⅲ established by the Ministry of Environment. Heavy metal pollution was not observed. Second, the level of water quality of small reservoirs is in the range of level Ⅳ-Ⅴ higher than the level Ⅲ established by the Ministry of Environment. Especially, water quality of Sinchang and Shinchung reservoir is worser than that of other reservoirs. Water quality of Asan and Sapkyo lakes is the range of level Ⅲ-Ⅴ. As the level of T-P and T-N is level Ⅳ and level Ⅴ, respectively, eutrophication might be progressed. Kogkyo river and reservoirs in Asan city is alreadlly very polluted by inflow of wastewater from residents, animal husbandries and industries. Recently, Metropolitan Area Development Planning(MADP) for Asan bay-area was suggested by the Ministry of Construction. According to this plan, industrialization and urbanization of Asan area will rapidly progress. If sewage and wastewater treatment facilities are not provided, water quality of river and reservoirs in Asan city will be worse. In order to prevent of environment pollution, first, the impact of industrialization and urbanization of Asan area on the environment should be considered at the beginning of MADP. Second, total effluent regulation of water pollution, air pollution and soil wastes, based on the self-purification of the Asan city environment, should be enforced.

유기성 폐기물의 산발효 특성 및 알카리 전처리에 관한 연구 ( Characteristics of Acid Fermentation and Alkali Pretreatment of Organic Wastes )

박종안,허준무 대한환경위생공학회 2001 대한환경위생공학회지 Vol.16 No.1

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.

一部 樂器의 演奏音에 의한 暴露歷이 聽力에 미치는 影響

박종안,장봉기,이종화,안규동,이영세 순천향대학교 산업의학연구소 1997 순천향산업의학 Vol.3 No.1

This study was carried out to evaluate the effect of playing musical instruments on hearing threshold level from May to October, in 1997. Pure tone audiometric tests was provided to musical instruments playing group of total 117 subjects(Samullnori; 35, military band; 25, symphony orchestra; 46, piano; 11), and reference group of total 7,477 subjects, selected after excluding workers with history of ear disease, of ototoxic drug administration, of noise induced hearing loss at workplace in Pohang industrial area. In addition, noise exposure levels of musical instrument players were assessed by noise dosimetry(exchange rate; 5dB, threshold level; 80dB, criterion level; 90dB), and produced age-adjusted hearing threshold level(=hearing threshold level of musical instrument player - hearing threshold level in same age of normal population group). The age-adjusted hearing threshold levels were analyzed by musician's career. The results were as follows; 1. The hearing threshold level of reference group was revealed more increased as within 4.98dB to 6.89dB at 1 KHz and within 5.26dB to 14.46dB at 4 KHz by ages than "the Standard of Age-adjusted Hearing Loss by Frequency(OSHA)" used for special health examination in the Ministry of Labour. 2. Equivalent continuous sound exposure level (Leq) by the group of instrumentalist was as following; within 104.95 to 112.62dB in samullnori, the highest, within 100.18 to 103.49dB in military band, within 77.00 to 82.74dB in symphony orchestra and 81.54dB in piano, the lowest. Playing maximum sound level by each musical instrument was as following; 122.8dB in Kkwaenggwari, the highest, 122.7dB in Changgo, 121.8dB in Alto saxophone, 115.5dB in Trumpet, 119.2dB in Horn, 112.8dB in Pungmul Buk and Ching, 112.5dB in Clarinet. 3. Average age-adjusted hearing threshold levels of instrumentalists were -0.65±6.38dB in left ear, -0.92±6.59dB in right ear at 1 KHz, and -1.14±12.88dB in left ear, -1.53±12.77dB at 4 KHz, which were better than normal, but the average age-adjusted hearing threshold levels of Samullnori players were 1.23±5.22dB in left ear, 1.94±6.91dB in right ear at 1KHz, and 8.40±15.75dB in left ear. 7.13±14.97dB in right ear at 4KHz, which were worse than normal. 4. Hearing threshold level in Samullnori players was increased with their career at 4 KHz, especially it increased rapidly when the musicians had played over 10years. It showed that there was a significant relationship between hearing threshold level and the career (P<0.01).

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.

디지틀 PSK 변조기를 위한 BTF설계에 관한 연구

박종안,문용선 조선대학교 국토개발연구소 1986 국토개발연구 Vol.6 No.2

It is shown that where data signal have to be transmitted over ordinary telephone lines, the use of PSK modulator which consists of only BTF with bandpass transfer function and logic circuit make it possible to modulate data signal into analog signal. In this paper, We derived a simple formula to evaluate coefficients of BTF for digital PSK modulators, designed BTF according to it, and considered experimental results.

一部 農村地域의 給水 施設과 住民의 病源性腸內細菌 感染狀態에 關한 疫學調査

高光均,李康淳,朴鍾安 순천향대학교 1983 논문집 Vol.6 No.2

A epidemio1ngica1 survey was carried Out to get hold of the distribution of pathogenic enterobacteria in Chung cheong nam-do. The specimens were collected in Seosan-Gun and Asan-Gun, during from July 19, 1982 to May 8, 1983. The total number of 1,734 specimens were obtained from various sources; 1,601 specimens from rectal swabs from persons and 133 specimens from drinking water source. The isolation and identification of pathogenic enterobacteria were performed by means of bacteriological, serological studies. 1. The isolation rates of pathogenic enterobacteria among the total 1,734 specimens are as follow; Salmonella species 0.40%(7 strains), Shigella species 0.63%(11 strains), and Vibrio parahaemolyticus 0.17% (3 strains). 2. Eleven strains of salmonulla were isolated from rectal swabs. Its serotyping Was identified as Salmonella typhi. 3. Eleven strains of Shigella were isolated from rectal swabs. The distribution of shigella serotype was identified as Sh. boydii 45.5% (5 strains). Sh.. dysenteriae 36.4% (4 strains) and Sh. flexneri 13.9% (2 strains). 4. Three strains of Vibrio parahaemolyticus were isolated from rectal swabs. Of the 3 strains, the 2 strains were agglutinated with type K-24, 1 strain of the others with K-33. In the water supplied by piped systems and of wells in sampling areas, the Chemical components were below the maximum Contaminant levels approved by EPA of drinking water.