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.

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.

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.-

미용입 십자형 필렛용접부의 기하학적 피로특성

李龍福,金慶燮 弘益大學校 科學技術硏究所 2000 科學技術硏究論文集 Vol.11 No.-

Fatigue failure modes of symmetrical LOP fillet weldments are dependent on the characteristics of the fatigue crack initiation and propagation from the weld toe or the weld root. In this study, constant amplitude fatigue tests on symmetrical LOP fillet weldments carried out, and fatigue properties were evaluated. Also, an attempt was made to develop the fatigue strength and fatigue life of symmetrical fillet weldments containing lack of penetration. From the result of this study, fatigue crack growth characteristics of symmetrical LOP fillet weldments are found to be affected by the weld geometry, stress range and microstructures of the welding zone.

복합비타민 유제의 제조와 평가

이문석,조혜영,이용복 한국약제학회 2002 Journal of Pharmaceutical Investigation Vol.32 No.1

Water-lipid soluble multivitamin formulations were widely used to reduce the disease and stress of animals as husbandry has made a remarkable progress in recent. But the efficiency of these formulations is far from satisfactory. So, this study was attempted to develop the physically and chemically stable and useful multivitamin o/w emulsion. Multivitamin o/w emulsion composed of water, soybean oil (10%, vlv), vitamin A, D, E, K, B_2, B_6, B_12 and panthenol. To make a stable o/w emulsion, the egg lecithin (2%, w/v) and glycerin (2.5%, w/v) were used for emulsifier and thickening agent, respectively. The oil in water emulsion system was manufactured by microfluidizer and the physicochemical stability of this emulsion was evaluated. The average particle size and interfacial tension were measured. From the result of interfacial tension tested, critical micelle concentration of the egg lecithin was 0.5% (w/v) and optimal concentration for the preparation of emulsion was 2% (w/v). The mean particle size was about 0.6 μm which was suitable for injections. Short-term accelerated stability as physical stability study was tested by centrifuging and freeze-thawing the emulsion samples. The additions of vitamins resulted in the increment of particle size and reduction of physical stability of emulsion. But it is not an enormous problem for the stability of emulsion. Also, we have performed the long-period preservation stability test for the vitamins. All vitamins were analysed by HPLC. The result of storage under 4℃ and dark conditions demonstrated that all vitamins were maintained stable at least 16 weeks, except for vitamin B_12.

AMS 감축과 쌀 수매정책의 효과

이용기,이용복 영남대학교 지역발전연구소 2003 영남지역발전연구 Vol.32 No.-

WTO 규정에 의한 총AMS(aggregate measurement of supports) 감축제약 조건 하에서, 현행 쌀 산업 약정수매제가 쌀 생산 및 농가소득에 미치는 효과를 분석하였다. 이론적 및 실증적 시뮬레이션 분석결과는 정부의 수매가격 인상이 쌀 생산과 생산자의 소득을 반드시 증대시켜 주지는 않는다는 것을 보여주었다. 이런 결과가 나타나게 되는 주요 원인은 정부 수매가격, 즉 지지가격뿐 아니라 시장가격의 생산 의사결정과 농가소득에 상당히 큰 영향을 미치기 때문이다. 즉, 수매가격의 인상은 단기적으로 쌀 생산을 늘리고 그만큼 생산자의 소득을 증대시키는 효과가 있겠지만 총AMS를 감축시켜야 하는 상황에서 이는 결국 초과공급으로 나타나 시장가격의 하락을 초래하여 쌀 생산과 소득증대에 악영향을 미치게 되는 것이다. 특히, 최근 몇 년의 상황처럼 쌀의 재고 누적과 초과공급이 존재하는 상황에서 그 악영향은 더욱 명백해진다. 국내·외의 변화된 시장환경으로 정책효과는 별로 거두지도 못하면서 국제사회로부터 보호주의 정책으로 강한 비난의 대상이 되고 있는 현행 약정수매제도는 재검토되어야 할 시점에 와 있다. WTO에서 녹색정책(Green Box)으로 분류되고 있는 공공비축제로 전환될 필요가 있다.

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.

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.

初期 缺陷形狀에 따른 表面龜裂傳播 特性에 關한 硏究

李龍福,金鍾鉉,李錫俊 弘益大學校 1990 弘大論叢 Vol.22 No.2

In this study, the diameters and depths of the intial surface crack configuration on the specimen was discharge processed differently and considered about propagation behavior and fatigue lifetime of the surface fatigue crack in each case. The result of this study are Summerized as follow; 1. Under the given constant condition, aspect ratio is regular in surface crack propagation, and early its differenceis large according to the initial surface crack configuration but it shows the same change aspect according to the propagation of the crack. 2. In general, for constand initial crack depths we may expect that initial crack lifetime is increased as diameter of specimen is increased because of relaxation of the stress concentration. Practically, however it is different according to the crack. 3. Early, Surface crack configuration has semi-circle and it has semi-elliptical according to crack propagation. 4. When the initial surface crack aspect ratio is in the range of 5∼6, the initial surface crack is propagated to inner surface under the condition, which ratio is smaller than the range. In the ratio is lager than that range, crack is propagated to outer surface.

과학경진대회의 문항과 분석과 학습지도 방안

이용복,배영부 서울교육대학교 과학교육연구소 1996 科學과 數學敎育 論文集 Vol.22 No.-