• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.20 no.3
• /
• pp.882-890
• /
• 1996

Mechanical properties, including Young's modulus, residual stress and rupture strength, of a thermally evaporated gold film have been measured form a blister test. In a theoretical study, the priniple of minimum potential energy and that of virtual work have been applied to the pressurized circular membrane problem, and load-deflection relations have been derived for typical membrane deflection mode of spheroidal shape. In an experimental study, circular gold membranes of 4800 A-thickness and 3.5mm diameter were fabricated by the silicon electropolishing technique. Mecahnical properties of the thin gold films were deduced from the load-deflection curves obtained by the blister test, Young's moduli, obtianed from blister test, have been in the range of 45-70 GPa, while those of bulk gold have been in the range of 78-80 GPa. Residual stresses in the evaporated gold films have been measured as 28-110MPa in tension, The rupture strength of the gold film has turned out to be almost equal to that of dental gold alloy (310-380MPa). It has been demonstrated that the present specimen fabrication method and blister test apparatus have been effective for simultaneous measurement of Young's modulus, residual stress and repture strength of thin solid films. Especially, the electropolishing technique employed here has provided a simple and practical way to fabricate thin membranes in a circular or an arbitrary shape, which could not be obtained by the conventional anisotropic silicon mecromachining technique.

• Composites Research
• /
• v.18 no.5
• /
• pp.21-26
• /
• 2005

The validity of Eshelby-type model with Mori-Tanaka's mean field theory to predict the effective material properties of composites have been investigated in terms of filler size and its arrangement. The 2-dimensional plate composites including constant volume fraction of fillers are used as the model composite for the analytical studies, where the filler size and its arrangement are considered as parameters. The exact effective material properties of the composites are computed by finite element analysis(FEA), which are compared with effective material properties from the Eshelby-type model. Although the fillers are periodically or randomly arranged, the average Young's moduli by Eshelby-type model and FEA are in good agreement, specially for the ratio of specimen size to filler size being smaller than 0.03. However, Poisson's ratio of the composite by the Eshelby-type model is overestimated by $20\%$.

• Journal of the Microelectronics and Packaging Society
• /
• v.9 no.4
• /
• pp.35-45
• /
• 2002

The stresses of the underfill/chip interface due to thermal loading was studied using the finite element method. At first, the effective properties of underfill for several volume fractions of silica particles were calculated by Mori-Tanaka method for three different material sets, and the parameters of singularity for the bimaterial edge and the bimaterial wedge were calculated. Consequently, the stresses at the underfill/chip interface with volume fraction of silica particles were investigated. Five different geometric models of flip-chip assembly involving two kinds of bimaterial strips and three kinds of three-layer models were considered under the assumption that the underfill is homogeneous. It was assumed that all components of the flip-chip assembly were linear elastic and isotropic, and their properties were temperature independent. The analysis was conducted in the context of the uncoupled plane thermo-elasticity under a plane strain assumption.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
• /
• v.23 no.2
• /
• pp.210-217
• /
• 2010

Objective : The purpose of this study is to know the effect of Yeonggyechulgam-tang on BPPV. Methods : Three patients were taken Yeonggyechulgam-tang with acupunture. And we used visual analogue scale(VAS). Results : After the treatment the grade of VAS was decreased and clinical symptoms were gradually disappeared. Conclusion : Yeonggyechulgam-tang was effective treatment of BPPV.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.19 no.4 s.74
• /
• pp.389-398
• /
• 2006

Structural optimization design has been developed with finite element analysis using effective and fast computational technology. Especially topology optimization design has been recently often used since it yields an optimal topology as well as an optimal shape under satisfied constraints. In general in finite element analysis, it is assumed that the structural material properties such as Young's modulus and Poisson's ratio and the variable of applied loading are fixed with obvious values in structure. However practically these values may take uncertainties because of environmental effect or manufactural error of structures. Therefore static or dynamic analysis of the structures may make an error, then finally it may have an influence on qualify of optimal design. In this study, the topology optimization design of structure is carried out using so called the interval finite element method, and the analysis method Is proposed. The results are also validated by comparing with conventional topology optimization results of density distribution method and finite element analysis results. The present method can be used to predict the optimal topology of linear elastostatic structures with respect to structural uncertainty of behavior.

• The Journal of Engineering Geology
• /
• v.5 no.1
• /
• pp.95-103
• /
• 1995

This paper concerns the use of derivative null constraint in an adaptive array pmcessor in the spatial and frequency domains with respect to a composite array processor to obtain a modified composite array processor. It is assumed that the frequency of interference signals is the same as that of a desired signal, interference directions are different from the desired signal, and interference directions and frequencies are known. Simulation results demonstrate that a higher-order derivative null broadens the null width which is appropriate for eleminating a broadband interference and a zero-order derivative null (i.e., a simple point null) with respect to frequency reduces the residual error inherent in the composite array precessor.

• The Journal of Engineering Geology
• /
• v.20 no.1
• /
• pp.47-60
• /
• 2010

This study is focused on the analysis of tunnel behavior to estimate the stability on tunnel design. An estimation method was proposed as a hybrid consideration, which contains the displacement analysis by 3D numerical simulation, the maximum displacement obtained after field measurement, and an assessment of tunnel stability using a deformation analysis proposed by Sakurai(1988, 1997). The points of case study by Sakurai(1988, 1997) were replotted considering his analysis. From the new analysis of the tunnel case study, the trend line for analyzed points is analogized, which curve is divided into stable, unstable and failure zone. To evaluate the estimation method, a special shape of railway tunnel was selected, which are the Inchon international airport rail way connected to subway line 9 in Gimpo, Korea. The point s of upper and below track on the Inchon international airport rail way were satisfied to the stability of tunnel after reinforcing. Also the points shows the higher apparent Young's modulus, which resulted from improvement on shear strength by the micro silica grouting and the supporting of umbrella method. Therefore, if new analysis used, proper tunnel reinforcing method could be selected according to tunnel strain and geological property.

• 한국정보교육학회:학술대회논문집
• /
• 2004.01a
• /
• pp.287-295
• /
• 2004

오늘날 지식정보사회에서는 국가의 과학기술이 그 나라의 국가 경쟁력을 좌우하게 되기 때문에 우수한 잠재력을 가진 영재를 조기에 육성하고 교육하는 일은 매우 중요하다. 특히 요즘처럼 지식정보사회로의 전환이 급속도로 진행되고 있는 현실을 고려해 볼 때에 영재교육 중 정보과학영계교육의 중요성은 더욱 커지고 있다. 사람들은 흔히 '영재'라는 이유로 기초가 되는 부분을 소홀히 하고 넘어가는 경우가 많다. 정보과학영재를 위한 교육과정 중 기초기술소양교육도 마찬가지였다. 대부분 프로그래밍 같은 고급기술을 요하는 것만 중시하지 워드프로세서나 프리젠테이션 프로그램 활용 같은 컴퓨터 사용에 기본이 되는 것들은 간과하고 넘어가는 경우가 맡았다. 하지만 기초가 단단해야 튼튼한 건물을 지을 수 있고, 뿌리가 깊어야 바람에 안 흔들리듯이 정보과학영재를 위한 교육과정 중 기초기술소양교육의 중요성은 무시할 수가 없다. 특히 컴퓨터에 대한 강한 호기심과 높은 창의력 등 정보과학영재로써의 많은 것을 갖추고 있지만 단지 기초기술이 부족한 아동은 정보과학영재가 아니라고 단정지어 말 할 수가 없기 때문에 기초기술소양교육은 매우 필요한 것이다. 따라서 본 논문에서는 정보과학영재교육의 필요성과 초등정보과학영재를 위한 기초기술소양교육의 필요성을 생각해 보고, 현재 일반적으로 이루어지고 있는 기초기술소양교육을 분석해 보고 단편적인 기능이 중심이 아닌 문제 해결 중심의 새로운 기초기술소양교육방안을 제시하고자 한다.

• Journal of Korean Medical classics
• /
• v.19 no.1 s.32
• /
• pp.207-210
• /
• 2006

${\ulcorner}$상한잡병론(傷寒雜病論)${\lrcorner}$에 나오는 양허증의 병인병리(病因病理)에 대한 내용을 종합하여 검토하고, 그 처방의 구성 약물과 용약 규율에 대하여 살펴본 결과, 양허증을 치료하는 상용약물로는 부자 계지 건강 오수유 생강 등이 쓰였음을 알 수 있었다. 임상에서 약을 사용할 때에는 장부의 생리적 특징에 근거하여 약물을 배합하여야 좋은 효과를 얻을 수 있다. 예를 들어 심양허(心陽虛)에는 계지감초(桂枝甘草)에 복령(茯笭)을 배합하고, 신양허(腎陽虛)에는 진무탕(眞武湯) 신기환 등(等)에 복령(茯笭), 택사(澤瀉), 백출(白朮) 등의 약물을 배합하여, 비양허(脾陽虛)로 인한 담음(痰飮)에는 계지감초(桂枝甘草)의 신감(辛甘)한 약성으로 화양(化陽)하고, 복령(茯笭), 백출(白朮)로 건비리습(健脾利濕)하는 영계출감탕을 사용하며, 심하(心下)에 수(水)가 정체된 경우에는 윗 처방에 사인 백두구 등의 온건비위(溫健脾胃)하고 성비소식(醒脾消食)하는 약물을 가하여 사용한다. 폐양허(肺陽虛)하여 폐위가 된 경우에는 감초(甘草) 건강(乾姜) 등을 사용하여 온폐복기하는데, 이는 ‘배토생금(培土生金)’의 의미이다. 간양허(肝陽虛)가 나타나는 경우는 매우 드문데, 위기가 허한(虛寒)하여 간(肝)이 소설(疏泄)작용을 못할 때에는, 오수유(吳茱萸)로 온위산한(溫胃散寒)하고, 인삼(人參) 대조(大棗)로 보중익기하며, 오수유(吳茱萸) 생강(生姜)의 신산(辛散)작용으로 간기를 다스리는 오수유탕(吳茱萸湯)을 사용하여 강역지구(降逆止嘔)하며, 혼(魂)을 수렴하지 못하여 생긴 실안(失眼)에는 산조인탕(酸棗仁湯)으로 보간(補肝)하여 치료하며, 간경(肝經)에 한사(寒邪)가 침입하여 근맥이 연급(攣急)하게 된 경우에는 지주산(蜘蛛散)을 사용하여 온경산한(溫經散寒)한다.

• Korean Journal of Poultry Science
• /
• v.19 no.1
• /
• pp.27-34
• /
• 1992

Seventy-five commercial male day-old broiler chicks were used to investigate the effects of Oxytetracycline(OTC) and Lonicera japonica Thunberg(LJT) to be active in anti-bacteria and anti-virus on the growth rate, carcass rate and various intestinal organs sizes in broiler at 3 wk of age. Five experimental diets were formulated to have similar protein and energy levels, with OTC 0.04％ as low-level antibiotics and OTC 0.34％ as high-level antibiotics and 0.5％, 1.0％, 3.0％ level of LJT. Birds were housed randomly in 15 battery cages. Birds were 3 replicates per treatment and 5 chicks per replicate. In the body gain, 0.5％ level of LJT addition grew significantly higher than the other birds. The feed intake and feed efficiency were not significantly between other birds. The addition levels in OTC and LJT did not any consistent effect on the carcass rate. However, the chest meat percentage vs carcass volume in LJT 0.5％ treatment and the leg meat percentage vs carcass volume in DTC 0.04％ addition level were significantly higher than those of birds fed other diets. The liver weight rate was significantly higher in OTC 0.04％ level. However, the 0％ and LJT levels did not exert any consistent effect on the weights of gizzard, heart, bursa of fabricius, head and spleen of broilers. The abdominal and gizzard surrounding fat content rate was higher in bird LJT 1.0％ level than birds fed other levels.