• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.693-694
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• 2008

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1998년도 제27회 춘계학술대회
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• pp.131-138
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• 1998

In this study, a numerical procedure to solve a contact problem has been developed. The procedure takes the advantage of signal processing technique in frequency domain to achieve the shorter computer processing time. The Boussinesq's equation was adopted as the response function. This procedure is applicable to the non-periodic surface profile as well as the periodic one. The validity of this procedure has been established by comparing the numerical results with the exact solutions. The effectiveness of this procedure is lied on the shorter computing time than any other contact analysis algorithm.

• 한국농공학회지
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• 제31권2호
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• pp.66-81
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• 1989

The characteristics of resilient modulus(Mr) which dominates the life of pavement and the design of pavement were investigated on the test specimens which were cement treated and non-treated of the three different soil types. The results are summarized as follows : 1. The resilient modulus was decreased by increasing the cyclic deviator stress ($\sigma$d) , especially the resilient modulus was gradually decreased or sometimes increased when the value of ad was greater than 0.75- 1. 0kg/cm$^2$. 2. The resilient modulus was increased by increasing the homogeneous confined stress ($\sigma$do) and such phenomena were distinct on the coarse soils. 3. The resilient modulus was increased by increasing the ratio of confined stress(Kc), and this phenomena were eminent on the coarse soils too, and the higher permanent strain was showed by increasing the value of Kc. 4. In the drained cyclic triaxial compression test, the value of ad, Kc, and (Oho) was introduced by the following interrelated equations which were similar to the Mr model of Cole. Kcn/Mr=K1(J$_2$/ $\tau$oct)K2 ............. (coarse soli) Mcn/Mr=K3($\sigma$dp/ $\tau$f)k4 ...............(fine soils) 5. The stress path was not much affected by the value of Mr, however, moisture content, dry desity, and contant of fines affected the value of Mr. 6. In the soil-cement specimens, the resilient compression strain($\varepsilon$d) was decreased by the increment of the $\sigma$ho, and Mr was decreased by increasing the $\sigma$d 7. In the flexible pavement. the cement treated layer should be designed not to fail by the fatigue before the designed traffic load, and actually the pavement could cover the traffic load to a certain extent under the post-crack phase, therefore farther studies on this phenomena' are required in the design analysis. 8. The finite element computer program (ANALYS) was used for displacement analysis of pavement containing the cement-treated layer, The result showed that the program used for this analysis was proved to be usable.

• 대한화학회지
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• 제37권5호
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• pp.473-476
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• 1993

디프로파질디페니메탄$(C_{19}H_{16})$는 단사정계의 공간군 $C2/_c$에$ 속하며 a = 11304(3), b = 20.799(5), c = $6.622(2)\AA$, $\beta$ = $112.8(3)^{\circ}$, Z = 4, V = $1435.3\AA^3,\;F(000)\;=\;520,\;D_c\;=\;1.14g{\cdot}cm^{-3}$ and $\mu$ = 0.32 cm$^{-1}$이며 I $\geq$ -1.0 $\sigma(I)$인 1328개의 회절반점에 대한 최종 R값은 0.055였다. 직접법에 의하여 구조를 풀었으며 수소를 제외한 모든 원자는 E-map에서 찾았다. 한 분자는 단위세포내에 있는 결정학적 2-회전축과 일치하는 대칭축을 분자내의 메탄의 탄소원자에 가짐으로서 $C_2$ 점군에 속한다. 직선인 프로파질 부분은 벤젠기의 분자평면과 거의 수직$(94.2^{\circ})$을 이루고 있으며, 메탄의 탄소원자의 내부각은 $108.1(1)^{\circ}으로$ 벤젠기와는 $1.530(2)\AA$, 프로파질기와는 $1.560(2)\AA$의 길이로 결합하고 있다. 분자사이의 가장 짧은 접촉은 C(9)과 C(9)(-x,y, -1/2-z)사이의 $3.538(2)\AA$ 이다.