• 산업공학
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• 제16권2호
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• pp.140-148
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• 2003

This study was performed to measure the various dimensions of the hand for Korean adults. Three hundred and eighteen males and two hundred and sixty females, age ranged 18 to 60, participated in this study. Thirty-five dimensions were selected to measure. Subjects were divided into three age groups, 18 to 29, 30 to 39, and 40 to 60, for each sex. The data were analyzed to see the differences between the age groups and sex by using SAS program. The results showed that the measurements related to breadth and thickness tended to increase as the age increased. Wrist breadth, index finger breadth(distal), index finger breadth(proximal), thumb breadth, and index finger thickness(proximal) increased as the age increased for both males and females (p<0.05). However, the measurements related to length tended to increase as the age decreased. The relationship between the parts that are length related showed high correlation. Hand length showed high correlation with palm length, middle finger length and index finger length. Males' were significantly greater than females' in every dimension (p<0.05). Also, the results of this study were compared with the data of Japanese and U.S. army. The results of this study can be used to design the hand related products.

• 대한치과보철학회지
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• 제54권2호
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• pp.160-166
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• 2016

정상적인 수준의 생리적 마모는 수정이 필요 없으나, 치아 경조직의 상실 속도가 비정상적으로 빠른 경우에는 치아에 심각한 손상을 야기하고 심미적, 기능적 구조를 파괴할 수 있다. 전반적인 치아 마모를 보이는 환자의 치료를 위하여 전악을 보철로 수복하고, 교합거상이 필요할 수도 있지만, 마모된 전치부의 보철 수복을 위한 가용공간 때문에 수직교합고경에 변화를 주는 경우가 아니면 잘 변경시키지 않는다. 본 증례의 환자는 마모된 치열과 치관 파절을 주소로 내원한 74세 남자 환자이다. 임상검사 결과 구치부 지지에 의해 수직고경의 감소가 없음을 확인하고 수직고경 변화 없이 전악 수복하여 만족할 만한 결과를 얻었기에 이를 보고하고자 한다.

• International Journal of Concrete Structures and Materials
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• 제18권1E호
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• pp.23-28
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• 2006

In this study, the general theory of fractality is discussed to provide a fundamental understanding of fractal geometry applied to heterogeneous material surfaces like pavement surface and rock surface. It is well known that many physical phenomena and systems are chaotic, random and that the features of roughness are found at a wide spectrum of length scales from the length of the sample to the atomic scales. Studying the mechanics of these physical phenomena, it is absolutely necessary to characterize such multi scaled rough surfaces and to know the structural property of such surfaces at all length scales relevant to the phenomenon. This study emphasizes the role of fractal geometry to characterize the roughness of various surfaces. Pavement roughness and rock surface roughness were examined to correlate their roughness property to fractality.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.1491_1492
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• 2009

The impedance of a vertical grounding electrode is not lowered by expanding the dimension of the grounding electrode, and the length of thr vertical grounding electrode which shows the minimum value of the grounding impedance for each condition of frequency and soil characteristics is existent, and it is defined as Critical length. In this paper, the critical lengths for the vertical grounding electrodes are calculated by using the distributed parameter circuit model. The adequacy of the simulations has been confirmed by comparing the simulated results with the measured results.

• Journal of Welding and Joining
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• 제14권2호
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• pp.71-78
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• 1996

In order to rpovide proper SMT design criteria in a systematic way, a mathematical formulation has been developed to predict the configuration of the solder fillet formed between the gullwing type lead and rectangular pad. Effects of SMT design parameters such as the solder volume and pad dimension on the solder profile are investigated using the FEM that calculates the 3D configuration by minimizing the energy due to surface tension and gravity in the equilibrium state. Design criteria of QFP and SOP are illustrated by plotting the acceptable range of the solder volume with respect to the length and width ratios of the pad and lead. The results show that the acceptable design range increases with increase in the pad length and width. The pad length has more significant effects on design criteria compared with the pad width, and Bond number can be utilized to predict the joint quality.

• 대한수학회보
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• 제45권3호
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• pp.419-425
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• 2008

For $q^5-q^3-q^2-q+1{\leq}d{\leq}q^5-q^3-q^2$, we prove the non-existence of a $[g_q(6,d),6,d]_q$ code and we give a $[g_q(6,d)+1,6,d]_q$ code by constructing appropriate 0-cycle in the projective space, where $g_q (k,d)={{\sum}^{k-1}_{i=0}}{\lceil}\frac{d}{q^i}{\rceil}$. Consequently, we have the minimum length $n_q(6,d)=g_q(6,d)+1\;for\;q^5-q^3-q^2-q+1{\leq}d{\leq}q^5-q^3-q^2\;and\;q{\geq}3$.

• 대한기계학회논문집B
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• 제30권10호
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• pp.987-995
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• 2006

A reversed trapezoidal fin with the fluid in the inside wall is analyzed and optimized in this study. As a fin base boundary condition, the heat transfer from inside wall fluid to the fin base is considered. The values of fin base temperature with the variations of inside wall fluid convection characteristic number and fin base length are listed. The heat transfer, fin effectiveness, fin length and fin base height are optimized as a function of fin base length, convection characteristic number ratio, fin shape factor and fin volume.

• 한국추진공학회지
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• 제16권3호
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• pp.90-96
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• 2012

복합재 연소관의 접합 체결부 최적의 설계 길이를 결정하기 위해 접합부 길이변화에 따른 구조해석을 수행하였다. 이때, 접착 체결부의 길이는 50 mm에서 300 mm의 범위를 갖는다. 무응력 상태의 초기 접합부 길이대비 응력구배가 발생하는 않는 구간의 길이를 "응력구배 길이 비"로 정의하고 이를 접착 체결부 길이선정을 위한 평가기준으로 정의하였다. 구조해석 결과 접착 체결부의 길이가 200 mm 이상으로 증가할 경우 응력구배 길이 비의 증가가 서서히 나타남을 확인하였다. 이는, 접착 체결부에 적용되는 2,500 psi 내압에서 구조적 안전성을 확보하는 최적화된 접착 체결부의 길이가 200 mm임을 의미한다.

• 한국소음진동공학회논문집
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• 제23권2호
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• pp.185-191
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• 2013

This paper presents a new method for roller design of IRB(isolation roller bearing) seismic isolation device using experimental evaluation. Three layered plate is adopted for the IRB in which the upper plate is placed on x direction and the lower plate is placed on y direction. The rollers placed in each plate make a plate movement. The roller is then optimally designed using variable geometric conditions. Stress distribution depends on the diameter and length of the roller and hence this is used for the determination of optimal geometry of the roller. In the experimental evaluation, it is observed that stress concentration at the end sides of roller is decreased and geometric coefficients depend on crowning dimension. In addition, in order to determine optimal design parameters of the roller the plastic deformation and friction are experimentally identified.

• 한국정밀공학회지
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• 제31권7호
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• pp.615-622
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• 2014

Copper pipes have been widely used as components of System Air-Conditioner due to high thermal conductivity. This system consists of 150 pipes, which are approximately 10m long in total. Dimensional changes occur during pipe processing such as expansion, reduction and bending. This processing induces changes in length of pipes and makes dimensional differences from original pipes. The summation of the differences of pipes components leads to make huge cumulative dimensional differences. The cumulative differences can cause serious problems such as crack, refrigerant leakage. However the differences have not been considered so far. To satisfy target quality of the system, it is essential to predict and calibrate the differences. In this paper, the changes in dimension were predicted using FEM and it was found that cumulative differences could cause indesirable stress during assembly process. As a result, dimensional differences or indesirable stress could be reduced using the proposed method.