모 연취급장 근로자들의 연폭로지표들과 혈압과의 관련성

임상복,김용배,이용진,리갑수,김화성,황규윤,장봉기,이성수,안규동,이병국 순천향대학교 산업의학연구소 1998 순천향산업의학 Vol.4 No.1

In order to investigate the relationship between blood lead with other lead exposure indices and blood pressure in occupationally lead exposed male workers, 629 workers(515 lead exposed workers and 114 non lead exposed workers) in a storage battery factory were studied. Blood lead(PbB), zinc protoporphyrin(ZPP) and urinary δ-aminolevulinic acid(ALAU) were selected as an index of lead exposure. Height and weight were also meaured with calibrated automatic height-weight machine to produce fatness index directly. Personal information on smoking and drinking history were also collected. Blood pressure was mearured by trained nurses with automatic sphingomanometer. All workers took at least 30 minute rest before their measurement of blood pressure. The results obtained were as follows: 1. The prevalence rate of hypertension of lead exposed and non-exposed workers were 3.5% in both group without any difference. 2. There were no differences of systolic and diastolic pressure between groups divided by lead exposure, smoking habit, drinking habit. but the increase of age group made the difference of diastolic pressure, and only differenct of systolic pressure observed in age group of less than 20 and that of more than 40. 3. In pearson's correlation analysis, PbB was correlated with systolic pressure significantly, but not with diastolic pressure. PbB was also correlated with pressure difference(systolic pressure-diastolic pressure). 4. There were no significant increase of systolic, diastolic pressure and pressure difference by the increase of PbB and ZPP grouping. 5. Stepwise multiple regression analysis using systolic pressure as dependent variable and PbB, ZPP, ALAU, age, work duration, smoking habit, drinking habit and fatness (weight*0.9/height-100) as independent variables, revealed that PbB, age, drinking habit and fatness in order were significantly contributed to the dependent variable. 6. Stepwise multiple regression analysis using diastolic pressure as dependent variable and PbB, ZPP, ALAU, age, work duration, smoking habit, drinking habit and fatness (weight*0.9/height-100) as independent variables, revealed that ALAU, age and fatness in order were significantly contributed to the dependent variable. 7. Stepwise multiple regression analysis using pressure difference as dependent variable and PbB, ZPP, ALAU, age, work duration, smoking habit, drinking habit and fatness(weight*0.9/height-100) as independent variables, revealed that PbB, age and fatness in order were significantly contributed to the dependent variable. 8. Logistic analysis of hypertensive conditions with categorized blood lead and other selected categorized independent variables indicated that only age(40> and 40≤) and fatness(1.0> and 1.0≤) were significantly contributed to dependent variable with 95% significant odd ratio confidence interval. With above results, lead exposure in terms of blood lead seemed to be minimally contributed to the raise of blood pressure, and the effect of blood lead was found to be more prominent on the pressure difference than the systolic and diastolic pressure themselves.

고정 스트레스 상태의 흰쥐에서 할로페리돌 전처치가 뇌생아민의 대사에 미치는 영향

이수복,양병환,김이영,이용성,고재경,김광일 漢陽大學校 精神健康硏究 1991 精神健康硏究 Vol.10 No.-

SM45C鋼 熔接部의 殘留應力에 依한 疲勞破壞擧動

李龍福,金鍾鉉,金相準 弘益大學校 1987 弘大論叢 Vol.19 No.2

Fatigue fracture behaviors of submerged arc welded SM45C steel were investigated when a crack propagated from tensile residual stress region. The experimental values were compared with the values expected by the Forman equation. The results are summarized as follows: 1. When the fatigue crack was propagated the experimental values were found to corresponded to the values predicted by Formane quation. 2. The experimental values in weld metals have a little difference to the values expected by Forman equation. It was assumed that residual stresses were relaxed by repeated tensile loading. 3. The higher stress ratios were, the larger the difference of fatigue crack growth rate always were in the Same stress intensity factor range for each stress ratios. Particularly, these differences of fatigue crack growth rates were smaller in weld metal than in base metal. It agrees with the fact of that the difference of .effective stress ratios for each stress ratios is small.

FCAW 십자형 용접재의 피로거동에 관한 연구

李龍福,吳炳德 弘益大學校 科學技術硏究所 2001 科學技術硏究論文集 Vol.12 No.-

The influence of weld size(l/t) and specimen geometry(a/w) on fatique life and fatique crack growth rate of flux cored arc welded(FCAW) cruciform joints, containing lack of penetration(LOP) defects, has been studied experimentally. It was found that fatique life of the weld joint increases with the larger weld size(l/t) and the smaller specimen geometry(a/w) and exhibits significant variations in low stress region. the crack growth rates are relatively higher with the smaller weld size(l/t) for a constant stress intensity factor range(AK), and are faster with the larger stress intensity factor range. The longer weld leg length appears to be beneficial for the fatigue life in an allowable range of weldment size.

고능률 소형 전자석에 의한 자왜 및 자기이방성 측정

이용호,신용돌,김병걸,민복기,송재성 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.17 No.-

자왜 또는 자기이방성의 측정에 사용되는 전사석의 여자전류를 측정에 필요한 수초간만 흘려서 에너지 소모 및 측정시의 최대난점인 시료의 온도변화의 문제를 극소화하였다. 따라서 전자석의 냉각장치는 생략되고 크기와 전원의 용량도 극소화되었다. 공기간격 22㎜, 자극의 단면적 40 × 25㎟에서 0.5 T의 자장발생에는 180 W의 전원으로 족하였다. 시료의 자왜와, 자기이방성에 의한 토크를 전기용량센서에 의하여 측정하여 10^-8의 자왜분해능과 1 nJ의 토크 분해능을 얻었다. 0.02× 0.8× 10㎟의 연자성 리본의 형상이방성을 이용하여 이방성 측정시의 토크값을 교정하였다. A high efficiency small electromagnet(22㎜ air gap and 40 × 25㎟ core's cross section) suitable for measuring magnetostriction and magnetic anisotropy was built. The magnet could be miniaturized by reducing the measuring space and time. The excitation current of the electromagnet was supplied for only a few second of small. An 0.5 T magnetic field was generated with 180 W power consumption. The values of magnetostriction and magnetic anisotropy were measured with a very sensitive capacitance cell with resolution of 10^-8 and 1 no. The torque was calibrated using a soft magnetic ribbon's shape anisotropy.

알루미늄合金(A5052-0) 熔接部의 疲勞破壤擧動에 關한 實驗的 硏究

李龍福,元光浩 弘益大學校 1985 弘大論叢 Vol.17 No.2

This research deals with Aluminum-Alloy (A5052-0) weldments. In this research the following conclusions are obtained. 1. when the fatique crack in heat affected zone propagates to base metal zone, total life is long in the following order, base metal, unrestrained weld metal, restrained weld metal, and fatigue crack growth rate is low in the same stress intensity factor range in the following order, base metal, unrestrained weld metal, restrained weld metal. 2. when the fatigue crack in base metal zone propagates to heat affected zone, total fatigue life is long in the following order, restrained weld metal, unrestrained weld metal, base metal, and at first time crack growth rate on base metal is higher than in weld metal but lower at the middle of specimen. 3. In E.C.T. specimen and C.C.T. specimen residual stresses in weldments largely act on fatigue behavior and in E.C.T. specimen mechanical properties of bead zone extend total fatigue life.

정책북한의 대외교역 구조적 특징

이원복,이용삼 국제무역학회 2001 국제무역연구 Vol.7 No.2

북한의 대외경제정책은 국가독점의 원칙, 자급자족경제의 원칙에 입각하여 자립경제 건설의 완성을 위한 보조적 수단으로 간주해 왔으므로 무역의존도는 높지 않았다. 따라서 자립적 민족경제 건설을 상위개념으로 경제발전에 꼭 필요한 상품을 수입하고 그에 필요한 외화를 얻기 위해 상품을 수출하는 것을 기본으로 하고 있다. 그러나 사회주의권의 붕괴로 대외경제협력의 기반이 상실돼 대외무역액이 급격하게 감소하게 되고 북한의 주요 원조국이었던 러시아와 중국마저 구상무역에서 경화결제로 전환함에 따라 북한은 대외무역의 중요성을 점차 인식하게 되었다. 북한은 이러한 경제난을 극복하기 위하여 개방과 개혁을 통한 대외관계 개선으로 교역규모를 확대하고 있다. 북한의 대외교역 규모는 2000년도에 전년대비 33.1% 증가하여 북한경제의 회복을 보여주고 있으며 교역상대국의 다변화를 위하여 노력하고 있으나 수출입물자를 수송할 인프라구축이 열악하여 수송이 용이한 아시아, 유럽과의 교역이 98.5%로 지역별 편중이 심한 무역구조를 가지고 있다. 국가별로는 중국, 일본이외에 태국, 인도 등의 동남아시아 국가들과의 교역이 급속히 증대되고 있다. 그리고 북한의 주요수출상품은 섬유, 전기·전자, 기계류, 수산물, 비금속, 광물, 플라스틱, 농임 산물 등이며 주요수입상품은 기계 및 전기·전자, 섬유, 에너지물자, 식량, 운송기기, 플라스틱, 화학공업제품 등으로 구성되어 있다. This paper represents the structural characteristics on foreign economic policy of North Korea by analyzing the status of trade and relations with foreign countries. The trade dependence of North Korea has not been high until 1980's before destroying socialism system since they import only necessary commodities for building self-economy. However the economic conditions of North Korea have the experience of minus growth and serious difficulties economically which is caused due to inefficient economic policy and due to destroying socialism system. Therefore this paper analyzes the current status of trade and structural characteristics of North Korea to understand how they are going to overcome their difficulties economically by opening economy positively.

龜裂닫힘 影響을 考慮한 表面疲勞龜裂 特性에 관한 硏究

李龍福 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.4 No.-

In this study, to evaluate the chraracteristics of fatigue crack propagation from the surface of material general structual rolled steel(ss41) was used, which was machined with surface pit shaped defects with different depths and radii. Surface fatigue crack characteristics considered crack closure effect could be well evaluated by experiments. The experimental results are summarized as follows: 1. The surface crack was varied to semicircular shape until a plate thickness ratio reachs 0.4 times and then become semi-elliptical shape. It could be expressed the fatigue crack shape by following equation. ?=1.0-0.67(?)+0.49(?)² 2. As the surface fatigue crack propargate, crack closure effect increases and has maximum value near crack depth with 0.5mm to 2mm and then decreases until it has bean constant value near crack depth ratio with 0.35 to 0.closure factor has 0.87 in the surface direction and 0.9 in the depth direction. 3. Considering the crack closure effect, it could be tacken crack closure ratio. ?=1.04 in both surface direction and depth direction and predicted characteristics of the surface fatigue crack correctly by using it.

후방압출 공정에서 금형과 제품변형 관계에 대한 연구

이강희,박용복,박태식 公州大學校工科大學生産技術硏究所 1999 論文集 Vol.7 No.-

The die for cold forging gets a very high axial load and radial pressure during processing and hence deforms considerably in the radial direction. This radial deformation of die becomes a important factor influencing the dimensional accuracy of a product. In order to obtain a product with highly accurate dimension. Therefore, it is essential to acquire some information on elastic deformation of the die and the product. The study has been performed for the relation of the deformation between a die and a product in backward extrusion. The strain of the die has been given by the simple experiment using the strain gauges attached to the outer surface of the die. Also the history of the deformation of the die and the product has been given by the experiment and Lame's formula. The results has been compared with the previous another method. The study has given useful results for the deformation history of the die and the product through the experiment and Lame's formula in backward extrusion, which can be applied in the die design for the product with accurate dimension.

성인 여성의 자궁경부암 및 유방암 조기검진 수검행위에 영향을 미치는 요인

노윤녕,김영복,박용문,이원철,맹광호 韓國保健敎育.健康增進學會 2000 보건교육건강증진학회지 Vol.17 No.1

This study was aimed at preparing basic dada required for establishment of a cancer screening program by examining the status of cancer screenings performed by women in a city and the factors that had an influence on cervical and breast cancers screening behavior of women. In order to find out the status of cervical and breast cancers screening and the factors having an influence on cervical and breast cancers screening behavior, 1,113 women were selected as study area and subjects by a random cluster sampling method, and the subjects were answered by questionnaires. The major results were as follows. 1.In the cases of the breast and the cervical cancers, 16.7% and 55.7% of the subjects turned out to have had one or more screenings respectively in their life-time. Also the rate of screening group of cervical and breast cancers was 16.7%, the rate of screening group of only cervical cancer was 38.9%, and the rate of non-screening group was 44.4%. 2.As to the screening pattern of cervical and breast cancer, there were significantly for age, income, occupation, married status, spouse, the factors associated with health promotion (doctor visiting, exercising), married age, number of children, and breast feeding(p〈0.05). 3.The factors associated with screening behaviors for cervical and breast cancers were age, income, occupation, married status, doctor visiting, exercising, married age, number of children, and breast feeding(p〈0.05). Based on the above-mentioned results obtained by this study, it was anticipated that this study may be play a vital role as basic data for the development and execution of cervical and breast cancers screening program for women in a community. And the analysis, done on the basis of the status of the cancer screening, of the influence factors on cervical and breast cancers screening behavior showed that for the development of a cancer screening program, the factors like age, social-economic class, married status, health promotion behavior, and reproductive characteristics should be considered.