• Journal of Preventive Medicine and Public Health
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• v.29 no.2 s.53
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• pp.173-186
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• 1996

This is a cross-sectional study to evaluate the relationships between physical fitness, leisure time physical activity, and serum lipid levels in middle-aged male workers. Physical fitness was measured by a step test score, and leisure time physical activity was self-reported on a questionnaire. Serum total cholesterol was negatively related to physical fitness(r=-0.27), and positively to obesity index(r=0.27). But leisure time physical activity was related to total cholesterol negatively(r=-0.20) only in subjects whose total cholesterol levels were above 170mg/dl. High density lipoprotein(HDL) cholesterol was positively related to physical fitness(r=0.15), negatively to obestiy index(r=-0.22), and positively to weekly alcohol consumption(r=0.14). Total cholesterol/HDL cholesterol ratio was related to physical fitness(r=-0.23), obesity index(r=0.32), total cigarette index (r=0.13), weekly alcohol consumption(r=-0.13), and vegetable preference(r=0.13). Physical fitness was also related to leisure time physical activity(r=0.19) and obesity index(r=-0.18). In multiple linear regression models, physical fitness(beta=-0.23) and obesity index(beta=0.18) were significantly associated with total cholesterol, obesity index(beta=-0.25) with HDLcholesterol, and obesity index(beta=0.30), physical fitness(beta=-0.16) and vegetable preference (beta=0.14) with total cholesterol/HDL cholesterol ratio. In conclusion, as physical fitness has a stronger relationship with serum lipid levels than leisure time physical activity, and the association between physical fitness and leisure time physical activity is modest, physical fitness should be added as an important variable in addition to activity in future epidemiologic studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.6
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• pp.2739-2746
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• 2011

This paper proposes the method for more effectively calculating X/R which is the ratio of equivalent reactance(X) and resistance(R) of the bulk power system and analyses the characteristic of X/R values by applying the proposed method to the real bulk power systems. X/R is used to determine the rating of the relay in the bulk power systems and its value has been accepted to be big enough to ignore the equivalent resistance of the bulk power systems. However, X/R is calculated as a big number when only the upper transformer and transmission line are considered. The correct approach to calculating X/R needs to consider all the parameters including generators, transformers, lines and loads. This paper calculates X/R of the bulk power systems using dynamic models which have been used to analyse the power system stability. The effectiveness of the proposed method is verified by applying it to the test system and X/R values of the real bulk power systems are analyzed. In addition, the dependence of X/R on the closeness of its calculating locations to the generator is verified by using the marginal loss factor which has been used in the electricity market.

• Transactions of the Korean Society of Mechanical Engineers
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• v.10 no.5
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• pp.645-652
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• 1986

For the analysis of equi-biaxial tension, the Lankford values at the various strain levels were measured experimentally at first. It was clarified that the R values depend on strain to a great extent and based on this result, the analysis of the equi-biaxial tension was carried out. Hill's new yield criterion was used to predict the stress-strain curves theoretically. The value of new parameter, m for the coincidence of the theory with the experiment was 2.1. It is desired that the optimum R-value in the case of m=2.1 is measured at strain, 15% for the reasonable correlation between theory and experiment.

• The Journal of the Petrological Society of Korea
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• v.25 no.2
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• pp.151-163
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• 2016

The characteristics of the rock cleavage in Jurassic granite from Geochang were analysed. The evaluation for the three directions of rock cleavages was performed using the parameters such as (1) frequency of microcrack spacing(N), (2) total spacing(${\leq}1mm$), (3) mean spacing($S_{mean}$), (4) difference value($S_{mean}-S_{median}$) between mean spacing($S_{mean}$) and median spacing($S_{median}$), (5) density of spacing(${\rho}$), (6) difference value between two exponents for the whole range of the diagrams(${\lambda}_H-{\lambda}_L$), (7) mean value of exponent(${\lambda}_M$), (8) mean value of exponential constant($a_M$), (9) difference value between two exponents for the section under the initial points of intersection(${\lambda}t_H-{\lambda}t_L$), (10) mean value of exponent(${\lambda}t_M$) and (11) mean value of exponential constant($at_M$). The results of correlation analysis between the values of parameters for three rock cleavages and those for three planes are as follows. The values of (I) parameters(1, 2, 7 and 8) and (II) parameters(3, 4 and 5) are in orders of (I) H(hardway, (H1 + H2)/2) < G(grain, (G1 + G2)/2) < R(rift, (R1 + R2)/2) and (II) R < G < H. On the contrary, the values of the above two groups(I~II) of parameters for three planes show reverse orders. Besides, the values of parameter $6({\lambda}_H-{\lambda}_L)$, parameter $9({\lambda}t_H-{\lambda}t_L)$, parameter $10({\lambda}t_M)$ and parameter $11(at_M)$ for three planes are in orders of R(rift plane, (G1 + H2)/2) < H(hardway plane, (R2 + G2)/2) < G(grain plane, (R1 + H2)/2), H < G < R, H < R < G and R < H < G, respectively. The values of the above four parameters for three rock cleavages show the various orders of R < H < G, R < H < G, H < G < R and H < G < R, respectively. Meanwhile, the spacing values equivalent to the initial points of contact and intersection between the two directions of diagrams were derived. The above spacing values for three rock cleavages are in order of rift(R1 and R2) < grain(G1 and G2) < hardway(H1 and H2). The spacing values for three planes are in order of rift plane(G1 and H1) < hardway plane(R2 and G2) < grain plane(R1 and H2). In particular, the intersection angles for three rock cleavages and three planes are in order of rift and rift plane < hardway and hardway plane < grain and grain plane. Consequently, the two diagrams of rift(R1 and R2) and rift plane(G1 and H1) show higher frequency of the point of contact and intersection. These characteristics of change were derived through the general chart for three planes and three rock cleavages. Lastly, the correlation analysis through the values of parameters along with the distribution pattern is useful for discriminating three quarrying planes.

• Transactions of the Korean hydrogen and new energy society
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• v.10 no.3
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• pp.171-175
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• 1999

Pd films($180{\sim}670{\AA}$ thick) were made by thermal evaporation. Electrical resistance of the films was measured during hydrogen absorption-desorption process at room temperature. Resistance changes as a function of hydrogen pressure in thin films of the PdH system show a strong dependence on film thickness. $({\Delta}R_{\infty}/R_0)_{{\beta}min}$ for a $\670{\AA}$ film is 0.61. For a $\180{\AA}$ film, this is 0.34. Resistance change also depends on sample preparation condition.

• Korean Journal of Poultry Science
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• v.49 no.2
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• pp.53-60
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• 2022

This study investigated correlations between egg quality indicators to identify external egg quality traits to predict internal egg quality using non-destructive and convenient measurements. Thirteen indicators, including Haugh unit, albumen height, eggshell breaking strength, eggshell thickness, eggshell color (CIE L^*, CIE a^*, CIE b^*), and reflectivity value, egg weight, egg length, egg width, shape index, and yolk color, were investigated. A total of 180 brown eggs were obtained from one 27-week-old flock of Hy-line brown-laying hens raised in a cage system. Correlations were evaluated using Pearson's correlation coefficient (r). The results showed strong correlations between Haugh unit and albumen height, eggshell color CIE L^* and reflectivity, egg weight and width, egg weight and length, eggshell color CIE L^* and CIE a^*, eggshell color CIE a^* and reflectivity, and shape index and egg length (P<0.001). Moderate correlations were observed between eggshell breaking strength and eggshell thickness, eggshell color CIE a^* and CIE b^*, and shape index and egg width (P<0.001). Eggshell color CIE L^* was correlated with eggshell breaking strength (P<0.01), and eggshell color CIE a^* was correlated with Haugh unit, albumen height (P<0.01), and eggshell breaking strength (P<0.001). The present study showed significant correlations between eggshell color and other quality indicators. Thus, this study suggests that eggshell colors based on reflectiveness and the CIE L^*a^*b^* value can be used to estimate the Haugh unit, albumen height, eggshell breaking strength, and thickness.

• Korean Journal of Materials Research
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• v.7 no.11
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• pp.934-941
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• 1997

C $r_{3}$ $C_{2}$-20wt% NiCr 이 크래드된 분말을 이용하여 HVOF 용사층의 특성(미세조직, 결정상, 경도 그리고 erosion rate)에 미치는 연료/산소 비(=3.2,3.0,2.8,2.6)의 영향을 조사했다. 실험범위 내에서 F/O=3.0의 경우가 C $r_{3}$ $C_{2}$-20wt%(NiCr)크래드 분말의 최적용사조건 이었다. XRD분석결과 F/O비에 관계없이 카바이드분해는 일어 났다. C $r_{3}$ $C_{2}$에서C $r_{7}$ $C_{3}$로의 상변화는 F/O비가 감소함에 따라 증가했다. 열처리 온도가 높아짐에 따라 C $r_{7}$ $C_{3}$분율은 증가 하였으며, 100$0^{\circ}C$에서 50시간 열처리후 용사층의 주된상은 C $r_{7}$ $C_{3}$이였다. 용사상태에서 경도값은 F/O=3.0조건으로 용사된 코팅층이 $H_{v300}$-1040으로 가장 높았으며, 공기중에서 $600^{\circ}C$, 50시간 열처리한 후, 경도값은 1340으로 증가하였다. 그리고 80$0^{\circ}C$열처리 후 경도값은 약간 감소하였다. 그러나 100$0^{\circ}C$ 열처리 후에도 1060정도로 용사상태의 경우 보다는 높은 경도값을 유지하였다. 이와같이 경도값이 증가하는 이유는 열처리에 따라 용사층이 치밀하게 되고 또한 C $r_{2}$ $O_{3}$의 산화물이 C $r_{3}$ $C_{2}$/C $r_{7}$ $C_{3}$ 내에 생성되어 탄화물/산화물 복합체를 이루기 때문으로 생각된다. 용사상태에서 drosion rate는 F/O비에 따라 2.6-3.05x$10^{-4}$mg/g까지 변화하였다. 또한 $600^{\circ}C$열처리 후에는 2.15-2.3 x $10^{-4}$mg/g이였으며, 80$0^{\circ}C$에서 열처리한 후에는 2.3-2.4x$10^{-4}$mg/g으로 $600^{\circ}C$열처리후 보다 약간 높은 결과를 보였다.결과를 보였다.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.82-90
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• 2009

Statement of problem: Recently, as patients' expectation and interest for esthetics are increasing, concerns of esthetic restoration for removable dentures as well as fixed prosthodontics are also increasing. And the color stability of artificial teeth will affect a long term success rate of the denture. But the stain or discoloration of these artificial teeth as well as denture resin has caused esthetic problem. Purpose: This study was designed to evaluate the influence on color stability of artificial teeth when soy sauce, red pepper paste and coffee which many Koreans have eaten were applied. Material and methods: For artificial teeth type(Endura $Anterio^{(R)}$, Physio $Duracross^{(R)}$, Trubyte $Biotone^{(R)}$) selected for the study, 10 specimens each were soaked into individual beakers of soy sauce, red pepper paste, coffee and distilled water. And $L^*$, $a^*$, $b^*$ value were measured for evaluation of the color difference (${\Delta}E^*$) with spectrophotometer on the 1 day, 1 week, 2 weeks, 4 weeks and 8 weeks after immersion. Results: 1. ${\Delta}E^*$ value of artificial teeth which were soaked in soy sauce and coffee was various according to soaking periods. However there was significant difference between Trubyte $Biotone^{(R)}$ and Physio $Duracross^{(R)}$ in red pepper paste regardless of soaking period(P<.05). 2. Except for 8 weeks of Endura $Anterio^{(R)}$, 4 weeks and 8 weeks of Physio $Duracross^{(R)}$, artificial teeth soaked in red pepper paste regardless of the type had significant difference of ${\Delta}E^*$ value compared with other groups (P<.05). 3. $a^*$, $b^*$ value of Endura $Anterio^{(R)}$ and Trubyte $Biotone^{(R)}$ which were soaked in red pepper paste had significant difference compared with the value of other group(P<.05). Conclusion: Red pepper paste had the greatest effect on color difference of artificial tooth. Physio $Duracross^{(R)}$ showed relatively less color difference than Trubyte $Biotone^{(R)}$ and Endura $Anterio^{(R)}$. But as ${\Delta}E^*$ difference were all less than 3.3, these artificial resin teeth seemed appropriate for clinical use.

• Journal of Korean Ophthalmic Optics Society
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• v.11 no.3
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• pp.193-200
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• 2006

We investigated the visual analysis of the far distance phoria for 83 subjects who have emmetropia or myopia eyes, using the graphic method, and determined new norms. We got the following results from these experiments. 1. The measured norm of far distance phoria is $1.12{\Delta}$, exophoria, the that of near distance phoria is $0.50{\Delta}$, exophoria, the that of negative relative convergence at far distance(N.R.C.) is ${\times}$/11/5, the that of positive relative convergence at far distance(P.R.C.) is 10/20/8, the that negative relative convergence at near distance(N.R.C.) is 11/21/5, the that of positive relative convergence at near(P.R.C.) is 10/20/8, the that of negative relative accommodation(N.R.A.) is +2.54D, and the that of positive relative accommodation(P.R.A.) is -2.60D, respectively. We know from theses results that the measured norms of far distancet phoria is higher than Morgan's norms, while those of near distance phoria are lower than Morgan's norms. 2. We also know from these experiments that Morgan's norms are closely related to A, B, and C groups and Morgan's criterion can more usefully apply to the visual analysis. 3. In Sheard's criterion and Percival's criterion, the prism prescription is occurred when the exophoria of the far-point phoria is over $7{\sim}9{\Delta}$, and the esophoria of that is over $4{\sim}6{\Delta}$.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.43-48
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• 2007

본 연구는 벼 군락의 분광반사율 지표를 측정할 수 있는 인공광원을 사용하는 능동형 광학 센서인 GNDVI 를 활용하여 생육시기별 식생지수와 엽 질소함량과의 관계를 구명하여 벼 군락의 엽 질소함량을 추정하고자 하였다. 농업과학기술원 답작 포장에서 공시품 종인 추청벼를 이용하여 난괴법 3반복으로 시험구 배치를 하고 질소 4수준 3반복으로 실험을 수행하였다. 벼 생육시기별 GNDVI 와 엽 질소함량과의 관계를 2년 간 (2005, 2006)의 자료를 통하여 분석해 보았다. 2005년의 경우 벼 생육시기동안 9시기의 GNDVI값과 그 당시 시료를 샘플링하여 분석한 엽 질소함량과의 관계를 벼 출수전과 출수후로 구분하여 분석해 본 결과 GNDVI 값은 출수전 ($r=0.78^{***}$ n=60) 보다 출수후 ($r=0.89^{***}$, n=59) 가 엽 질소함량과의 상관계수가 높았다. 2006년은 20시기동 안 생육시기별 식생지수와 엽 질소함량과의 상관 분석한 결과 착근기 (6월 5일) $r=0.84^{***}$, 유수분화기 (7월 11일) $r=0.95^{***}$, 출수기 (8 월 16일) $r=0.87^{***}$, 수확기 (10월 13일) $r=0.90^{***}$ 으로 출수전의 경우 7월 11일이 상관계수가 가장 높았고， 이 결과는 2005년 동일시기 (7월 11일) 식생지수와 벼 엽 질소함량과의 상관계수가 가장 높았던 ($r=0.91^{***}$) 것과 일치하였다. 벼 생육시기 변화에 따른 식생지수와 엽 질소 흡수량과의 관계를 살펴보았는데 벼 출수전의 경우 GNDVI는 7월 11일 에 엽 질소 흡수량과의 상관계수 ($r=93^{***}$)가 가장 높은 결과를 보였고 출수후의 경우에는 시기에 따라 상관계수가 고르게 높게 나타났다. 엽 질소함량과의 상관관계가 높았던 2005년，2006년 7월 11일 식생지수 데이터를 함께 이용하여 엽 질소함량과의 관계를 추정식으로 작성하였다. GNDVI를 이용하여 2005년과 2006년 실측한 엽 질소함량 값과 추정 값을 비교해 본 결과 2005년과 2006년의 결정계수가 각각 0.88, 0.94로 2006년이 더 예측률이 높게 나타났다. GNDVI 값을 이용하여 엽 질소함량 추정값과 실측값을 비교해 본 결과 결정계수가 0.86으로 추정값과 실측값이 근접하게 분포하였다.