• Journal of Oral Medicine and Pain
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• v.9 no.1
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• pp.103-116
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• 1984

Randumly sampled out 157 extracted Korean adult teeth, aged 12 to 79 years, was applicated to estimat the age by Gustafson's method, were evaluated and analyzed in terms of phyological aging change. The results are as follows : 1. It was reconfirmed that there existed comparatively close correlationship between age and score, especially in old age. 2. Korean score had comparatively high level than those of European. 3. In the probability of age edetermination, the estimation error was the most high level in the age of 70~ with ±4.47, and next order was in the age of 10-19 with ±5.20,60-69 with ±5.8,30-39 with ±5.98,50-59 ±6.20,40-49 with ±6.72,20-29 with ±9.28.Mean value was ±8.03. 4. The regression equation is as follows. y=3.55x+8.52(r=8.75) standard deviation σ=±8.03 (y= estimated age x=score) 5. In age determination with those data, needs to estimate slightly lower than caculated age in range of 10-49, and higher in 50-70 for the real age determination.

• Journal of the Korean Magnetics Society
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• v.2 no.2
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• pp.125-131
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• 1992

기판회전 테이블이 부착된 DC, RF-magnetron sputtering 장치로 유리기판 위에 제작한 1000 .angs. 정도의 8.8 .angs. Tb/X .angs. Fe (X=5.4~11.0) 다층박막에 관하여 시료진동형 자 기계와 타원편광 분석장치를 사용하여 자화, 수직자기이방성, kerr 회전각의 Fe층 두께와 열처리 온도 의존성이 연구되었다. Fe층 두께가 7.8 .angs. 기점으로하여 자화용이축의 전이가 나타나기 시작하여 6.4 .angs. 일때 수직자기이방성을 나타낸다. 실험치로부터 계산한 Fe와 Tb층의 경계면 수직이방성 에너지 $K_{s}$ = -0.38 erg/$cm^{2}$이고, Fe층만의 체적수직이방성 에너지 $K_{v}$ = -8.50 * $10^{5}$ erg/$cm^{3}$이다. Polar Kerr 회전각은 Fe층 두께 7.8 .angs. 에서 그대값 2 .THETA. $_{k}$ = 1.22 .deg. 를 갖는다.다.다.다.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.10
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• pp.568-574
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• 2017

The purpose of this study was to optimize experimental conditions (time ($X_1$) (ranging of 26.36 - 93.64 min), concentration of sulfuric acid ($X_2$) (ranging of 0-2.5%) and temperature ($X_3$) (ranging of $136.4-203.6^{\circ}C$) for an organosolv pretreatment process to extract lignin from waste wood. The resulting quadratic model equation using RSM (response surface methodology) represented y (lignin yield) = $-79.89+0.91X_1+9.8X_2-2.54{\times}10^{-3}X_1{^2}-2.11X_2{^2}$. The $R^2$ (coefficient of determination) value of 0.8531 for a model indicates this model has statistically significant predictors at the 10% levels. The predictive results optimized by quadratic model produced a lignin yield of 12.46 g/100 g of dry wood under conditions of $178.2^{\circ}C$ and 2.32% $H_2SO_4$. The lignin yield was more affected by the acid catalyst concentrations than the reaction temperature, but the reaction time was not an influential factor for improving lignin extraction from waste wood in this organosolv pretreatment. According to ANOVA (analysis of variance), the significance probability (p-value) of model was smaller than 0.001 and simulation of obtained model equations showed a good reproducibility based on actual organosolv tests under optimal conditions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.103-109
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• 1970

The results of this work concerning the growth of the mussel, Mytilus edulis cultured by the hanging method in Koje Bay are as follows: The major spawning time is confined to the period from March to April. The mean growth of the mussel is indicated by the following formula; $$Y\;=\;1.508+0.659X-0.0559X^{2}+0.00367X^3$$ The major growing seasons are June and October The variance varied in proportion to the growth of the mussel, and each ranged, in shell height, from $1.25\~2.75\;to\;2.25\~4.25$ (mean:1.60 to 2.78)cm, $2.25\~5.25(3.00)cm,\;2.25\~7.75(4.83)cm,\;2.25\~7.75(5.05)cm\;and\;2.25\~8.25(5.95)cm$, and the variance were $0.278\~0.230$, 0.368, 0.701, 1.053 and 1.209, respectively. On the other hand, the variances differed in proportion to the growth of the mussel. The average length of the mussel life was about eighteen months. The mussels growing on the hanging line for arrestation undergo seasonal vicissitudes, and the mussels which fall off, mass into countless numbers during the period from August to October and finally disappear completely in November. The dimensions of the largest mussel are as follows: The shell height : 9.48cm The shell length: 4.49cm The shell breath : 3.55cm The shell weight : 22.05g The weight of the soft parts 19.25g The relative growth of the mussel is indicated as follows: Relationship between the shell height and the shell length: Y =0.486X+0.334 Relationship between the shell height and the shell breadth: Y = 0.359X+0.107 Relationship between the weight of the soft part and the shell weight: Y = 0.882X+0.901 Relationship between the shell height and the weight of the soft part: $$Y\;=\;0.02828X^{2.90518}$$

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.8
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• pp.2043-2050
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• 2014

As most the scanning systems developed until now provide radiation scan plane images of the inspected objects, there has been a limitation in judging exactly the shape of the objects inside a logistics container exactly with only 2-D radiation image information. As a radiation image is just the density information of the scanned object, the direct application of general stereo image processing techniques is inefficient. So we propose that a new volume-based 3-D reconstruction algorithm. Experimental results show the proposed new volume based reconstruction technique can provide more efficient visualization for X-ray inspection. For validation of the proposed shape reconstruction algorithm using volume, 15 samples were scanned and reconstructed to restore the shape using an X-ray stereo inspection system. Reconstruction results of the objects show a high degree of accuracy compared to the width (2.56%), height (6.15%) and depth (7.12%) of the measured value for a real object respectively. In addition, using a K-Mean clustering algorithm a detection efficiency of 97% is achieved. The results of the reconstructed shape information using the volume based shape reconstruction algorithm provide the depth information of the inspected object with stereo X-ray inspection. Depth information used as an identifier for an automated search is possible and additional studies will proceed to retrieve an X-ray inspection system that can greatly improve the efficiency of an inspection.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.7
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• pp.907-912
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• 1993

In this Paper we have proposed a new method to implement the interpolation of the functions, using a neural network. The architecture of neural network is a three-layer perceptron and the training algorithm is a modified error back propagation algorithm adding neurons to hidden layer. The interpolated functions are sin(7 X), 3rd order polynomial 0.5$\times$3_2$\times$2+X+2.5 and rectangular pulse 0.99 U (X-0.2) -0.99 U(X-0.8) +0.01, where U(X) is the unit step. The root mean squred errors of the interpolated functions are 0.00258, 0.00164 and 0.00116 respectively.

• Journal of the Chungcheong Mathematical Society
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• v.8 no.1
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• pp.19-27
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• 1995

In 1974 H.Herrlich invented nearness spaces, a very fruitful concept which enables one to unify topological aspects. In this paper, we introduce the Lindel$\ddot{o}$f nearness structure, countably bounded nearness structure and countably totally bounded nearness structure. And we show that (X, ${\xi}_L$) is concrete and complete if and only if ${\xi}_L={\xi}_t$ in a symmetric topological space (X, t). Also we show that the following are equivalent in a symmetric topological space (X, t): (1) (X, ${\xi}_L$) is countably totally bounded. (2) (X, ${\xi}_t$) is countably totally bounded. (3) (X, t) is countably compact.

• Bulletin of the Korean Mathematical Society
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• v.53 no.1
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• pp.303-323
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• 2016

For a canonical threefold X, it is known that $p_n$ does not vanish for a sufficiently large n, where $p_n=h^0(X,\mathcal{O}_X(nK_X))$. We have shown that $p_n$ does not vanish for at least one n in {6, 8, 10}. Assuming an additional condition $p_2{\geq}1$ or $p_3{\geq}1$, we have shown that $p_{12}{\geq}2$ and $p_n{\geq}2$ for $n{\geq}14$ with one possible exceptional case. We have also found some inequalities between ${\chi}(\mathcal{O}_X)$ and $K^3_X$.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.200-205
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• 1999

In the ferromagnetic phase with electrons for La$_{1-x}$(Ca or Sr)$_x$MnO$_3$, films, a remnant resistivity of the order of 10$^{-8}$ ${\omega}$m is observed up to 100 K and increases exponentially with temperature up to T$_c$ and above one Tesla as a function of magnetic field strength (a positive magnetoresistivity). The phase below T$_c$ is regarded as a polaronic state with a polaronic tunneling conduction. Possible p-wave condensation (or superconductor) with a parabolic density of states and the phase separation are discussed on the basis of the two-fold degeneracy of ${\varrho}_{\delta}$ orbitals.

• Journal of the Korean Vacuum Society
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• v.5 no.2
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• pp.127-132
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• 1996

We measured photoreflectance spectrum characteristics of InGaAs grown by MBE method on semi-insulating GaAs. The PR signal splitting of substate and epilayer was observed. The band gap energy was about 1.40 eV. It make to 8 meV difference when it is fitted by Pan's equation. The reason is stress on the interface, which is due to lattice mismatch between epilayer and substate . We became to know that reason influence crystalline on growing sample. In InGaAs epilayer, temperature dependency is low. The efficiency of photo absorption is high and activate over 200K. In this case when it is annealed at $400^{\circ}C$ below growing temperature, PR signal splitting is remarkable and crystalline is inhanced.