• Textile Coloration and Finishing
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• v.18 no.5 s.90
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• pp.72-79
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• 2006

There are many discrepancies between visually perceived color-difference and that which is quantified from an instrumental measurement when dark color samples are measured in the textile industry. The samples were prepared to represent these dark shades and the values of the instrumental results from conventional color-difference formulae(CIELAB, CMC, BFD II, CIE94, LCD99 and CIEDE2000). Those of visual assessment were compared. The experimental results show that the CIELAB formula gives the best performance over other formulae, and the CIEDE2000 formula for the color-difference according to chroma presents the worst performance. Therefore, we can say that the problems in color matching of dark shades are caused by imperfect formula, because the results obtained from a color-difference formulae are different and the CMC which is used as a standard color-difference formula in the textile industry is not correct. So, a revised color-difference formula is proposed in this study, to account for these problems.

• Herbal Formula Science
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• v.21 no.2
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• pp.63-71
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• 2013

Objectives : Artemisia princeps is used as moxa in moxibustion and traditional herbal medicine. And its extracts or compounds is known to have an efficacy of antioxidant, anti-diabete, anti-cancer, anti-inflammation and neuroprotection. This study was performed to investigate the cytoprotective effect of Artemisia princeps extract (APE) against arachidonic acid (AA)+iron-induced oxidative stress on HepG2 cell. Methods : The effects of APE on cell viability has been assessed using MTT assay. And flow cytometric analysis was performed to estimate APE's effects on mitochondrial function. To investigate its underlying mechanism, related protein was analysed by using immunoblot analysis. Results : Treatment of APE increased relative cell viability, prevented a decline of B-cell lymphoma-extra large (Bcl-xL) and cleavage of poly(ADP-ribose) polymerase (PARP) and procaspase-3, and also protected mitochondrial membrane permeability (MMP) against oxidative stress induced by AA+iron. In addition, APE treatment increased phosphorylation of AMP-activated protein kinase (AMPK) exerts a cytoprotective effect. Conclusions : This results demonstrate that APE has an ability to activation of AMPK which protects cells from AA+iron-induced oxidative stress and restores MMP.

• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.23-30
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• 2011

In this study, Terzaghi's formula was modified to solve problems considering the dilatancy effect of the soil for estimating the earth pressure acting on tunnel. It is performed for the comparison with Terzaghi's formula and modified Terzaghi's formula, tunnel model test result of Kobe University Rock Mechanics Laboratory. From comparison results of the earth pressure acting on tunnel, the earth pressure calculated by the Terzaghi's formula was estimated largest value. The earth pressure measured through the tunnel model test was least value. The difference between the earth pressure derived from Terzaghi's original formula and that derived from the modified formula was caused by the dilation effect, which was caused by the soil volume change. The difference between the earth pressure derived from the modified formula and the earth pressure measured through the tunnel model test, earth pressure results from the energy making failure surface. The results of FEM analysis were almost consistent with the results of mathematical analysis.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.6
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• pp.72-82
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• 2000

Many lot of books introduce the methods to calculate the time of concentration, and these are described as various forms of formulas. There are few formulas appropriate for our basin characteristics Therefone, there are problems to make excessive or less estimation when these formulas are used. To solve these problems, comparison of formulas and sensitivity analysis for them were made with converting parameters. Finally, Time of concentration was estimated to derive Application limits for 3 watersheds by standardized formulas. In the case of input parameters analysis, SCS formula has the highest value by the length, Kerby by the height and SCS by the slope, respectively, while Kraven formula has the lowest value among them. Concerning the relative sensitivity by Taylor series, the time of concentration showed the constant effect while increasing of the length and slope, and the length was more sensitive than the slope in parameters. Finally the standardization formula developed in this study was applied to derive application limits for 3 watersheds(total 17 subbasins). In this case, Rziha(8 subbasins) and SCS(9 subbasins) formulas were the most similar to observed data of total 17 subbasins respectively. Application limits were about 300~500$\textrm{km}^2$ area, 30~60km length and under 0.01 slope for Rziha formula and about 100~200$\textrm{km}^2$ area, 10~30km length, and over 0.01 slope for SCS formula, respectively.

• Nuclear Engineering and Technology
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• v.46 no.4
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• pp.481-488
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• 2014

An analysis of the uncertainty quantification related to LBLOCA using the Monte-Carlo calculation has been performed and compared with the tolerance level determined by the Wilks' formula. The uncertainty range and distribution of each input parameter associated with the LOCA phenomena were determined based on previous PIRT results and documentation during the BEMUSE project. Calulations were conducted on 3,500 cases within a 2-week CPU time on a 14-PC cluster system. The Monte-Carlo exercise shows that the 95% upper limit PCT value can be obtained well, with a 95% confidence level using the Wilks' formula, although we have to endure a 5% risk of PCT under-prediction. The results also show that the statistical fluctuation of the limit value using Wilks' first-order is as large as the uncertainty value itself. It is therefore desirable to increase the order of the Wilks' formula to be higher than the second-order to estimate the reliable safety margin of the design features. It is also shown that, with its ever increasing computational capability, the Monte-Carlo method is accessible for a nuclear power plant safety analysis within a realistic time frame.

• Journal of Nutrition and Health
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• v.36 no.8
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• pp.841-850
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• 2003

Soy-based formula has been used for centuries in Korea. Soybeans contain phytochemicals with a biochemically active component, isoflavone. Isoflavone is a kind of phytoestrogens, structurally and functionally similar to estrogen. This study was conducted to investigate the effects of soy-based infant formula on growth, development, and isoflavone concentration in the plasma and urine. Thirty-nine healthy infants who were delivered at K university medical center were recruited. Experimental groups were the breast milk group (n = 15, BM) who were fed breast milk, soy-based formula group (n = 10, SBF) who were fed soy-based infant formula, and the casein-based formula group (n = 14, CBF) who were fed casein-based infant formula for 4 months. HPLC analysis was used to measure the concentration of isoflavones. The measurements of infant weight, length, head circumference and chest circumference were all in the normal growth range and were similar among the experimental groups. No significant differences were found in the scores of total mean of infant development test (Development Quotient, DQ) among the experimental groups. The isoflavone content of soy-based formula was significantly higher than. that of breast milk and casein-based formula. Plasma concentration of daidzein and genistein in the infants fed soy-based formula (daidzein : 264.1 ng/ml, genistein : 392.1 ng/ml) was significantly higher (p<.0001) than that in infants fed breast milk (daidzein : 3.4 ng/ml, genistein : 3.8 ng/ml) and casein-based formula (daidzein: 8.1 ng/ml, genistein: 9.3 ng/ml). Also, urinary daidzein and genistein concentrations in infants fed soy-based formula (daidzein: 19.82 $\mu$g/ml, genistein : 17.89 $\mu$g/ml) were significantly higher (p<.001) than those in infants fed breast milk (daidzein: 0.28 $\mu$g/ml, genistein : 0.22 $\mu$g/ml) and casein-based formula (daidzein : 0.45 $\mu$g/ml, genistein : 0.33 $\mu$g/ml).

• Bulletin of the Korean Mathematical Society
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• v.53 no.5
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• pp.1401-1409
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• 2016

In complex analysis, the Bergman kernels for two biholomorphically equivalent complex domains satisfy the transformation formula. Recently new Bergman theory of slice regular functions of the quaternion variables has been investigated. In this paper we construct the transformation formula of the slice Bergman kernels under slice biregular functions in the setting of the quaternion variables.

• Nuclear Engineering and Technology
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• v.31 no.3
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• pp.328-334
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• 1999

Based on the Euler beam theory and the elastic strain energy method, the elastic stiffness formula of the holddown spring assembly consisting of several leaves was previously derived. Even though the previous formula was known to be useful to estimate the elastic stiffness of the holddown spring assembly, recently it was reported that the elastic stiffness from the previous formula deviated greatly from the test results as the number of leaves was increased. The objective of this study is to extend the previous formula in order to resolve such an increasing deviation when increasing the number of leaves. Additionally, considering the friction forces acting on the interfaces between the leaves, we obtained an extended elastic stiffness formula. The characteristic test and the elastic stiffness analysis on the various kinds of specimens of the holddown spring assembly have been carried out; the validity of the extended formula has been verified by the comparison of their results. As a result of comparisons, it is found that the extended formula is able to evaluate the elastic stiffness of the holddown spring assembly within the maximum error range of + 12%, irrespective of the number of the leaves.

• International Journal of Aerospace System Engineering
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• v.2 no.2
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• pp.54-57
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• 2015

The purpose of this paper is to provide the method of conventional stress analysis for a pressurized hydraulic cylinder with internal thread undercut. In the case of hydraulic cylinder with thread undercut, several loads and stresses occur during operating. So, the thread undercut can be most critical section has to be considered in detail for strength check. In this paper, the conventional stress analysis method at internal thread undercut of hydraulic cylinder based on Kowalski's formula is introduced. The method is verified by comparing to FEM analysis results using ANSYS.

• Steel and Composite Structures
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• v.8 no.6
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• pp.491-510
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• 2008

This paper presents a plan and guidelines that were drawn for Korean based research carried out on the fire-resistance of CFT columns. This research was carried out by reviewing the Korean regulations related to the fire-resistance of CFT columns and examining studies which had been made in Korea as well as overseas. The first phase of the study plan was to compare the fire-resistance of square CFT columns without fire protection (obtained through fire-resistance tests and numerical analyses) with estimated values (obtained through fire-resistance design formulas proposed in Korea and overseas). This comparison provided conclusions as outlined below. Fire-resistance tests conducted in this study proved that, when the actual design load is taken into consideration, square CFT columns without fire protection are able to resist a fire for more than one hour. A comparison was made of test and analysis results with the fire-resistance time based on the AIJ code, the AISC design formula and the estimation formula suggested for Korea. The results of this comparison showed that the test and analysis results for specimens SAH1, SAH2-1, SAH2-2 and SAH3 were almost identical with the AIJ code, the AISC design formula and estimation formula. For specimens SAH4 and SAH5, the estimation formula was more conservative than the AIJ code and the AISC design formula. It was necessary to identify the factors that have an influence on the fire-resistance of CFT columns without fire protection and to draw fire-resistance design formulas for these columns. To achieve this, it is proposed that numerical analyses and tests be conducted in order to evaluate the fire-resistance of circular CFT columns, the influence of eccentricity existing as an additional factor and the influence of the slenderness ratio of the columns. It is also suggested that the overall behavior of CFT structures without fire protection within a fire be evaluated through analysis simulation.