不良住宅地區 改善政策에 關한 硏究 : 서울特別市를 中心으로

林相憲 건국대학교 행정대학원 1982 建國大學校 行政大學院 硏究論叢 Vol.10 No.-

FEM과 Thickness Analysis를 이용한 판금성형해석

林尙憲 영남이공대학 1997 論文集 Vol.26 No.-

Sheet metal forming processes experience very complicated deformations effected by processes parameters such as the blank shape, blank holding force, die geometry, sheet thickness, friction, and so on. Although these process parameters influence the deformation mechanism and the quality of deformed parts, the optimum values of process parameters are determined by intuition and experience through trial and error. A more systematic method such as finite element analysis can simulate complicated sheet metal forming processes and provide useful information. However, general finite element analysis is generally carried out with given process parameters and thus requires numerical trial and error with enormous time and cost to determine the optimum values of process parameters. For this reason, some approaches to find directly the process parameters have been developed In this method the input of mathematical model includes part geometry, forming node, material properties, forming speed, and coefficients of friction. The output includes strain distributions and forming severity derived from the Forming Limit Diagram. The mathematical model identifies critical forming zones during the initial part design stage and allows what-if scenarios to be investigated before the final design is committed to soft or hard tooling. The designer can evaluate various design versus production options for reducing the severity of the stamping. By the measuring of the thickness variation of deformed part on ultrasonic measuring machine and through the monitoring of forming process variables such as material variation and tool wear, the thickness analysis has product.

Stainless Steel판재의 성형성 평가에 관한 연구

임상헌 영남이공대학 1998 論文集 Vol.27 No.-

The purpose of this thesis is to obtain mechanical properties of stainless steel which is yield strengh, strain hardening coefficient, anistropic coefficient and forming limit diagram. And the theoretical FLD's are constructed by the data of mechanical properties obtained from the uniaxial tension test. So this thesis suggests that a particular forming limit band is constructed based on the experimental data with deep drawing process.

요중 비소농도와 N-acetyl-β-D-glucosaminidase 농도와의 관련성 평가

이용찬,임동혁,엄상용,김용대,김헌 충북대학교 의과대학 충북대학교 의학연구소 2010 忠北醫大學術誌 Vol.20 No.1

Purposes: This study was performed to evaluate the possibility of impairment of renal tubular function by exposure to inorganic arsenic of low concentration. Materials and methods: Study subjects were 867 individuals (365 men and 502 women) who resided around abandoned mine areas in Chungbuk Province, Republic of Korea. Information about the life style, drinking water type, seafood intake, and mine working history was gathered, and urinary arsenic concentration and N-acetyl-β-d-glucosaminidase (NAG) activity were measured. The correlation between arsenic concentration and urinary NAG activity was tested in groups classified according to urinary NAG activity and seafood consumption prior to urine sampling. Results: No statistically significant difference in urinary arsenic concentrations was observed between different gender and age groups. The participants those who ate seafood within three days before the urinary sample showed a higher mean urinary arsenic concentration than those who did not. In a correlation analysis between natural logarithm of urinary arsenic concentrations and that of urinary NAG activities, no statistical significance was found in a total sample as well as within a gender group. In a group with the urinary arsenic concentrations higher than the geometric mean and the urinary NAG activities higher the geometric mean, the correlation coefficient between two variables was 0.182 and significant. (p-value<0.05) Conclusions: It is suggested that renal tubular damage could be induced by non-occupational exposure to low level inorganic arsenic. 연구목적 : 본 연구는 폐금속광산 주변지역 주민들을 대상으로, 저농도 비소노출에 의하여 신세뇨관 기능이상이 유발될 수 있는지를 평가하는 것을 목적으로 시행하였다. 대상 및 방법 : 충청북도에 소재하고 있는 폐금속광산의 주변에 거주하는 주민 867명을 대상으로 직접 면접조사를 실시하였다. 대상자의 소변을 채취하여 요중 비소농도와 요중 N-acetyl-β-D-glucosaminidase (NAG) 활성을 측정하였고, 조사대상자를 역학적 변수에 따라 구분하여 두 변수 사이의 상관관계를 분석하였다. 결과 : 소변시료를 채취하기전 3일 이내에 해산물을 섭취한 사람들의 요중 비소농도는 그 기간동안 해산물을 섭취하지 않은 사람들의 농도에 비하여 유의하게 높았다. 조사 대상자들의 요중 NAG 농도의 평균값은 남녀차이가 없었으나, 65세 미만 대상자와, 표본을 채취하기 전 3일 이내에 해산물을 섭취한 사람들의 요중 NAG 활성도의 평균값은 그렇지 않은 사람들에 비하여 유의하게 낮았다. 요중 비소농도가 기하평균 이상이고, 요중 NAG 활성이 기하평균 이상인 군에서 두 변수의 상관관계가 0.182 로 유의하였다. 결론 : 정상범위의 비소 노출이라도 요중 비소농도가 8.28 μg/g creatinine을 초과하는 경우에는 미세한 신장손상을 유발할 가능성이 있으며, 해산물을 섭취함으로써 체내에 흡수되는 비소는 이러한 신독성이 거의 없다.

볼 나사의 BCD 정밀 측정기 개발에 관한 연구

이춘만,임상헌 국립7개대학공동논문집간행위원회 2004 공업기술연구 Vol.4 No.-

Amongst mechanical elements, a ball screw is the most important for feeding system. The ball screw requires high precision during machining process because a machine tool demands high accuracy. The high quality ball screw can be obtained by sustaining the lead accuracy, pre-load torque, and constant ball screw center diameter (BCD), etc. In this study, we are focused on the measurement of BCD and development of precision measuring instruments for the evaluation high quality ball screw. Finally, we can control the quality of a ball screw through the measurement of BCD.

진동 신호를 이용한 캠 프로파일 CNC 연삭기의 실험적 평가에 관한 연구

이춘만,임상헌 한국공작기계학회 2005 한국공작기계학회 춘계학술대회논문집 Vol.2005 No.-

A cam profile grinding machine is a mandatory machine tool for manufacture of high precision contoured cam. Experimental evaluation of modal analysis is an effective tool to investigate dynamic behavior of a machine. This paper presents the measurement system and experimental investigation on the modal analysis of a grinding machine. The weak part of the machine is found by the experimental evaluation. The results provide structure modification data for good dynamic behaviors. And safety of the machine was confirmed by the modal analysis of modified machine design. Finally, the cam profile grinding machine was successfully developed.

레이저 절단기의 구조해석 및 모드해석

이춘만,임상헌 國立 昌原大學校 産業技術硏究所 2002 産技硏論文集 Vol.16 No.-

A laser cutting M/C is designed for the precise fabrications in the machine recently. The cutter is a gantry type one with specified functions of movability and strength in order to satisfy the workability. The gantry frame should move with a certain velocity in a relatively short time for the proper cutting of the object materials. The gantry is fitted with rank and pinion and the acceleration field is formed by actuating this rack and pinion. The relative displacement should be within the allowable design criteria to make sure the precise cutting of the materials by the laser. In this paper, modal and structural analysis for a laser cutter which is commonly used in the fabrication of machine, is carried out to check the design criteria of the system. The system is modeled by placing the proper shell and solid finite elements and fictitious mass properties to represent the real one.

3차원 Bending Machine 설계 및 신뢰성 평가에 관한 연구

이춘만,임상헌,김현진 국립7개대학공동논문집간행위원회 2004 공업기술연구 Vol.4 No.-

This study is concerned about the development of a three-dimensional bending machine for heat exchanger. Recently, three-dimensional bending is required for various heat exchangers. The purpose of this study is the design of a three-dimensional bending machine by analysis of bending process, structural analysis simulation, and reliability evaluation of the machine by using a laser interferometer. The analysis is carried out by FEM simulation using DEFORM and CATLA V5 commercial software. The copper-tube is modeled by shell elements and the machine is modeled by placing proper shell and solid finite elements and fictitious mass properties to represent the real one. In addition, this machine has attained high accuracy repeatability. In order to improve the accuracy of this machine, the repeatability of feed, rotation, and bending are measured by a laser interferometer. The final results of analysis are applied to the design of three-dimensional bending machine and the machine is successfully developed.

한국인의 심근 조직내 카드뮴 농도의 참고치

박정덕,임헌방,최병선,권일훈,이상연,강은용,홍연표,장임원 大韓産業醫學會 1999 대한직업환경의학회지 Vol.11 No.1

Cadmium(Cd) is an ubiquitous, toxic and nonessential metal which is controversial about the association with a cardiovascular disease. In this study, we investigated the reference level of Cd in myocardium in Korean general population. The level of Cd and zinc(Zn) concentration in myocardium of 252 cases of "sudden and unexpected death" autopsies (male: 172, female : 60) aged 0 to 87 years was analyzed. The concentration of Cd and Zn was determined with atomic absorption spectrophotometer(Perkin-Elmer Model 5100) by flameless and flame method, respectively. The content of Cd and Zn in myocardium showed the log-normal distribution rather than normal distribution. Geometric mean concentration of Cd was 0.19 ㎍/g wet weight in myocardium. The level of Cd in myocardium was not significantly different between male (0.18㎍/g wet weight) and female (0.22㎍/g wet weight). Geometric mean concentration of Zn in myocardium was 25.25 ㎍/g wet weight. The level of Zn between male (25.13 ㎍/g wet weight) and female (25.57㎍/g wet weight) was not different. The deposit of Cd in myocardium was age-dependent of biphasic pattern, but the Zn level by age was not significantly different. The level of Cd in myocardium was increased to the fifties of age, thereafter a leveling-off was shown. The regression model of Cd deposit in myocardium by age was predicted as the following equation: Log Heart-Cd= -1.2726 + 0.0234 ·Age -0.0002 ·Age². The maximum Cd deposit in myocardium was estimated to be 0.26 ㎍/g wet weight at the age of 58.5 in Korean general population. In addition, the total Cd burden in heart by age was predicted as a following equation: Total Cd burden in Heart= -10.165+2.891 ·Age -0.0258 ·Age². The maximum heart burden of Cd was estimated to be 70.7㎍ at age of 55.4. The positive correlation between Cd and Zn was observed in myocardium. The linear regression equation was Log Heart-Zn = 1.4195+0.0262 ·Log Heart-Cd.

用寒遠寒과 用熱遠熱에 대한 考察 : 六元正紀大論에서

채영진,신창환,임현택,여성원,한성규,이재원,정헌영,금경수 한국전통의학연구소 2003 한국전통의학지 Vol.13 No.1

Five elements motion and six kinds of natural factors influence not only human disease but also difference of medicine effect. Because the climate of summer is very hot, that is easy to increase the properties of hot medicines, a doctor must be careful to use it in summer. Also the climate of winter is very cold, that is easy to increase the properties of cold medicines, a doctor must be careful to use it in winter. But in the certain conditions to use diaphoretics or purgatives, in spite of that regulation a doctor can use them.