직업적 연폭로가 일부 신경행동학적 검사수행에 미치는 영향

안익수,안현철,김용배,리갑수,김화성,황규윤,최은,장봉기,이성수,안규동,이병국 순천향대학교 산업의학연구소 1999 순천향산업의학 Vol.5 No.1

In order to investigate that blood lead levels of lead exposed workers is associated with decreased performance in neurobehavioral tests in adults, we investigate 78 workers in a battery industry. Three items among neurobehavioral core test battery of World Health Organization, including digit span, Santa ana dexterity, digit symbol were administered to workers occupationally lead exposed workers by operational guide for the WHO neurobehavioral core test battery. Blood lead (PbB) and zinc protoporphyrin in whole blood (ZZP) were selected as an index of lead exposure. Detailed occupational history such as exposed agent, age, work duration, smoking and drinking habits, were recorded as confounding factors. After controlling age, the results of digit span and digit symbol among the neurobehavioral tests were significant contributed by PbB.

연작업자들에서의 δ -aminolevulinic acid dehydratase 유전형질의 다형성이 신기능에 미치는 영향

안익수,황보영,김용배,리갑수,이성수,장봉기,함정오,안규동,이병국 순천향대학교 산업의학연구소 2001 순천향산업의학 Vol.7 No.1

δ-aminolevulinic acid hehydratase (ALAD) is a polymorphic enzyme that has two alleles, ALAD1 (ALAD1-1 as phenotype) and ALAD2 (ALAD1-2 or ALAD2-2 as phenotype). ALAD genotype has been reported to modify the toxicokinetics of lead. To investigate the influence of ALAD genotype polymorphism on renal function in lead workers, author studied 1022 male lead workers and 149 non lead workers in the same industries. For the cross-sectional renal function indices, blood urea nitrogen (BUN), serum creatinine, uric acid and total protein were selected. Blood lead and blood zinc protoporphyrin were also measured as indices of lead exposure. Information on weight, age, job duration, smoking & drinking history were collected. Following results are as follows: 1. Whereas the mean (standard deviation) of blood lead and blood ZPP of lead workers were 27.2±12.5 ㎍/㎗ and 57.7±37.8 ㎍/㎗, those of non-lead workers in the same premises were 14.9±6.5 ㎍/㎗ and 44.6± 15.8 ㎍/㎗ respectively. The difference of mean blood lead and blood ZPP between two groups were statistically significant. 2. Whereas the prevalence of the variant allele, ALAD2 in 1022 lead workers was 10.2 %, the prevalence of that in 149 non-lead workers was 7.4 %. But there was no difference of prevalence between two groups. 3. The mean±standard deviation of blood lead of subjects with ALAD1 was 25.5± 12.7 ㎍/㎗ and was slightly lower than that of subjects with ALAD2 (26.5±10.9 ㎍/㎗), and the mean±standard deviation of blood ZPP of subjects with ALAD1 was slightly higher than that of subjects with ALAD2 (56.7±37.3 ㎍/㎗ vs 48.9±18.6 ㎍/㎗). But the differences of blood lead and blood ZPP between two genotypes were not statistically significant. 4. There were no differences of cross-sectional renal function indices (BUN, serum creatinine, uric acid and total protein) either by lead workers and non-lead workers or two genotypes. 5. In multiple regression analysis of ALAD genotype on BUN after controlling for possible confounders (sex, weight, job duration, smoking and drinking status), the mean of BUN in ALAD2 subjects was 0.629 ㎎/㎗ lower than ALAD1 subjects with a weak statistical significance (p=0.07). But in logistic analysis of ALAD genotype on median value of BUN revcaled that subjects of ALAD2 genotype were 32% less likely to have median value or more of BUN than subjects of ALAD1 with odd ratio of 0.618 (95% confidence interval 0.411-0.920). 6. In multiple regression analysis of ALAD genotype on serum creatinine after controlling for possible confounders (sex, weight, job duration, smoking and drinking status), the mean of serum creatinine in ALAD2 subjects was 0.0271 ㎎/㎗ lower than ALAD1 subjects with statistical significance (p=0.02). On the other hand, in logistic analysis of ALAD genotype on median value of serum creatinine revealed that subjects of ALAD2 genotype were 30% less likely to have median value or more of scrum creatinine than subjects of ALAD1 with odd ratio of 0.700 (95% confidence interval 0.442-1.080). With the above results, it was found that the variant allcle, ALAD2 appeared to modify the association of lead and renal function and ALAD2 genotype may be supportive for the protective effect of lead.

國際決濟慣習上 TradeCard의 受容可能性에 관한 硏究

安秉壽 한국통상정보학회 2000 통상정보연구 Vol.2 No.2

지속적으로 변화하는 무역관습의 흐름은 결제관습에 있어서도 새로운 변화를 초래하고 있는데 최근의 국제결제시스템중 가장 두드러진 변화는 전자적 방법에 의한 결제시스템의 대두이다. TradeCard는 이러한 전자결제시스템으로서 가장 대표적인 예로서 1994년 처음 사업이 시작된 이후 10년도 되지 않아 새로운 무역결제관습으로 정착되기 위한 상업적 활동에 나서고 있다. 본 논문은 이러한 TradeCard의 상업적 활동이 과연 순조롭게 추진되어 신용장을 비롯한 기존의 무역결제시스템에 추가 또는 대체되는 새로운 무역관습이 탄생할 수 있을지를 검토하고 있다. 이를 위해 본 논문은 먼저 TradeCard가 갖고 있는 특징을 몇 가지로 분류하여 실펴보았다. 즉, 무역절차의 전자화 과정에서 기능적 접근방법을 채택하였다는 점, 타 기관이나 조직과의 활발한 제휴, 비용과 시간을 절감시킬 수 있는 방법의 제시 등이 그것이다. 이러한 특징을 통해 TradeCard는 새로운 무역관습으로 자리잡을 수 있는 충분한 가능성을 갖고 있다는 것이 논자의 생각이다. 그러나 다음의 몇 가지 문제점 역시 갖고 있기 때문에 이를 해결하는 것이 그러한 가능성의 전제조건이 된다. 첫째, TradeCard를 통한 거래의 법적 안정성 확보이다. 이는 모든 전자거래가 공통으로 갖는 문제점이지만 TradeCard의 경우 거래조건의 이행여부에 대한 전자적 판단이라는 요소를 지니고 있어 이를 어떻게 법적으로 수용할 것인가의 문제가 제기된다. 둘째, TradeCard를 통한 거래에서 발생되는 피해에 대한 구제방법의 제시이다. 이는 아마도 보험을 통해서 해결할 수 있으리라 생각되지만 현재 TradeCard는 이부분에 대한 명확한 입장이 명시되지 않은 것 같다. 셋째, 국제적 전자거래를 안전하게 할 수 있는 방안으로 전자서명의 활용이 절실한데 이에 대한 상호인정의 해결이 필요하다는 점이다. 물론 이는 TradeCard의 역할이라기 보다는 우리 정부를 비롯한 각국의 정부당국의 몫이다. 그러나 이러한 모든 문제는 결국 얼마나 빨리 많은 사용자를 확보하여 시장의 힘을 통해 국제상관습으로 정착시킬 수 있는가의 문제로 귀착된다고 본다. 따라서 TradeCard는 저렴한 요금체계 및 사용자에 대한 인센티브의 제공 등을 통해 조기에 다수 사용자를 확보하는 것이 시급한 것으로 생각한다.

단일전력단으로 구성된 AC/DC 풀 브리지 컨버터에 관한 연구

안병무,권순도,김용,백수현 동국대학교 산업기술연구원 2000 산업기술논문집 Vol.11 No.1

본 논문에서는 단일단 AC/DC 폴브리지 토포로지에 적합한 고주파 소프트 스위칭 컨버터응용에 근거를 두고 제안한다. 제안된 컨버터는 입력전류를 불연속 모드로 동작시켜 역률을 개선하며 입력전류의 zero-crossing-point에서의 왜곡을 개선함으로써 고조파를 감소시켜 고역률, 영전압 스위칭, 저잡음과 고효율을 구현한다. 펄스폭 변조 제어방식은 각각의 스위칭과 정류손실을 저감하기 위해 사용되었다. 제안한 컨버터는 IGBT를 전력스위치로서 주로 사용되지는 고전압, 고전력 컨버터응용에 적용할 수 있으며, 실험을 통하여 1.5kW, 30kHz로 동작하는 컨버터를 구현하였다. A single stage AC/DC converter based on a full bridge topology suitable for high frequency soft switching converter applications is proposed. The power factor correction can be achieved by the discontinuous conduction mode(DCM) operation of the input current. The proposed converter gives the good power factor, low line current harmonics. The proposed converter has high power factor, zero voltage switching low noise and high efficency. A pulse width modulation control is employed to reduce the switching and rectification losses respectively. The proposed converter is attractive for high-voltage, high-power applications where IGBT's are predominantly used as the power switches. The principle of operation, features, and design are verified on a 1.5kW, 30kHz, IGBT based experimental circuit.

Selective Nitration에 의한 3-Phenyl-4-(p-aminophenyl) Sydnone의 합성

안찬묵,윤병희,유학수 연세대학교 자연과학연구소 1986 學術論文集 Vol.16 No.-

3,4-Diphenylsydnone에 조건을 변화시켜가면서 니트로화반응을 시켰다. 반응은 4위치의 phenyl에서만 일어났으며, CH_3COOH-HNO_3조건하에서는 para에 그리고 H_2SO_4-HNO_3조건하에서는 ortho와 para에 진행하여 각각 니트로화합물을 얻었다. 생물학적으로 활성을 갖을 것으로 기대되는 아미노기를 갖는 sydnone유도체를 얻기 위하여, 이 니트로화합물을 Fe와 2%초산수용액에 의해 환원시켰다. 이들 생성물의 확인은 IR과 NMR로 검토하였으며 원소분석으로 확정지었다. Nitration of 3,4-diphenylsydnone was examined under various conditions. Reaction took place only at phenyl which was at 4-position of sydnone ring, and it was found that para-substituent was obtained under CH_3COOH-HNO_3 condition, whereas under H_2SO_4-HNO_3 condition ortho-and para-substituent was obtained. In order to obtain amino group containing sydnone derivative which was expected to be biologically active, this nitro compound was reduced by iron and 2% aqueous acetic acid. The products thus obtained were identified by IR and NMR spectroscopy and confirmed by elemental analysis.

미세 펀칭 구멍의 디버링 특성에 관한 연구

안병운,최용수,박성준,윤종학 한국공작기계학회 2003 한국공작기계학회 추계학술대회논문집 Vol.2003 No.-

In micro hole punching process the burr occurs inevitably, but the burr must be minimized in order to improve the quality and accuracy of the product. In this study, magnetic field assisted polishing technique is applied to remove the burr which exists in nozzles for ink jet printer head and proved to be a feasible for deburring by experiment. The deburring characteristics of sheet metals was investigated changing with polishing time. After the deburring, the burr size has remarkably reduced and roundness of the hole also has improved.

Wolff-Parkinson-White증후군의 임상상 및 전기생리학적 소견

안신기,이문형,장양수,오동진,최인석,하종원,임세중,김병옥,정남식,심원흠,조승연,김성순 대한순환기학회 1997 Korean Circulation Journal Vol.27 No.9

선박용 엔진 모니터링을 위한 CSMA/CD 프로토콜

안병원,김현수,윤경국 木浦海洋大學校 1998 論文集 Vol.6 No.1

This study is on the development of a monitoring system which can be applied for not only large vessels but also small vessels less than 20 gross tonnage. The Monitoring system consists of many LMU(Local Monitoring Unit)s that collect data from local machinery, a host computer that controls LMU and a stable communication system. In this paper, the industrial computer is used as host computer and that is compotable to IBM PC. GUI(Graphic User Interface) for main program is constructed by the use of HANGUL library and BOLAND C??, so this software package is easy to access to beginners. The LMU is made up from 80C196KC, which consists of CPU, interface, digital input/output, analog input/output and communication. Communication system between the host computer and LMUs is the multidrop configuration using RS-485 method. One master device of industrial computer has the role of host computer and LMUs acts as slave devices. And, more efficient communication system is practicable by the aid of polling method as well as carrier sense multiple access with collision detection(CSMA/CD) protocol.

인체감염 동양안충(Thelazia callipaeda)에 대하여

안영겸,이규재,양우익,정평림,김기수,백병태 연세대학교 원주의과대학 1993 원주의대논문집 Vol.6 No.1

고강도 철근콘크리트 기둥의 전단강도

안병익,정수영 忠南大學校 産業技術硏究所 1995 산업기술연구논문집 Vol.10 No.2

This paper presents experimental and analytical results on shear strength of reinforced concrete columns subjected to constant axial compression and lateral cyclic loadings. Results of tests evaluate Korean Code and Japanese Code The parameters of this experiment are axial compression ratio, amount of shear reinforcement and concrete compressive strength. As a result of the evaluation, the shear capacity Calculated with both Codes shows a good agreement with minimum shear reinforcement ratio(60㎏/㎠) in low axial compression ratio and concrete compressive strength. But, in case of high axial compression stress(up to 0.4f'c) and high strength concrete(up to 800㎏/㎠), shear capacity of specimens is estimated lower than Korean Code and Japanese Code.