• Computers and Concrete
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• v.25 no.3
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• pp.193-204
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• 2020

In the study, a new, simple and alternative formula is proposed to calculate numerically crack widths of concrete on a finite element (FE) model. By considering more general tension softening behavior of concrete, the proposed expression is derived irrespective of any tension softening model given in the literature or design codes. The test results of six reinforced concrete (RC) deep beams having different geometrical and material properties selected from a recent existing experimental study of the authors are used to verify the accuracy and reliability of the proposed formula and the created numerical FE models of the specimens. Moreover, the crack width results obtained from the FE models are compared with the test results to see the performance of the proposed formula. The results of the study demonstrate that the proposed formula gives very accurate results in a comparison with the test results. The ratios of errors on the results stay commonly at an acceptable level as well. Consequently, the proposed formula is quite simple, unique, and robust to determine crack widths of RC deep beams on an FE model.

• Journal of Pharmaceutical Investigation
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• v.20 no.2
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• pp.55-64
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• 1990

Soybean fatty acid, the largest byproduct in the production of soybean oil, was formulated for hand cream, oil in water emulsion base, to improve the suppleness and elasticity of skin. The stability of emulsion observed by a macroscopic method was used as a characteristic index for deciding an optimum formula of hand creams. The optimum formula of the most stable hand cream was obtained from polynomial regression equation, contour graphs and partial derivative graphs. The values of soybean fatty acid and stearyl alcohol in the obtained optimum formula were 9.75 and 14.75 w/w%, respectively, and sodium lauryl sulfate was not needed. Experimental value for the stability of hand cream prepared according to the optimum formula was 76,14 days, and the prediction value by computation method was 73.25 days. From the results of accelerated tests by elevated temperature, the stability of hand cream by optimum formula was 1.7 year at room temperature $(25^{\circ}C)$. The hand cream containing soybean fatty acid was found to be free of primary irritant substance to the skin by Draize technique.

• Structural Engineering and Mechanics
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• v.25 no.6
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• pp.717-732
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• 2007

A formula to approximate the fundamental period of a fixed-free mass-spring system with varying mass and varying stiffness is formulated. The formula is derived mainly by taking the dominant parts from the general form of the characteristic polynomial, and adjusting the initial approximation by a coefficient derived from the exact solution of a uniform case. The formula is tested for a large number of randomly generated structures, and the results show that the approximated fundamental periods are within the error range of 4% with 90% of confidence. Also, the error is shown to be normally distributed with zero mean, and the width of the distribution (as measured by the standard deviation) tends to decrease as the total number of discretized elements in the system increases. Other possible extensions of the formula are discussed, including an extension to a continuous cantilever structure with distributed mass and stiffness. The suggested formula provides an efficient way to estimate the fundamental period of building structures and other systems that can be modeled as mass-spring systems.

• Communications of the Korean Mathematical Society
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• v.29 no.3
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• pp.429-437
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• 2014

Motivated by the recent investigations of several authors, in this paper we present a generalization of a result obtained recently by Choi et al. ([3]) involving hypergeometric identities. The result is obtained by suitably applying fractional calculus method to a generalization of the hypergeometric transformation formula due to Kummer.

• Bulletin of the Korean Mathematical Society
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• v.50 no.4
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• pp.1261-1275
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• 2013

We establish an integral formula for the first Chern number of a compact almost Hermitian surface and derive curvature identities from the integral formula. Further, we provide some results as applications of the identities.

• Communications of the Korean Mathematical Society
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• v.15 no.4
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• pp.707-714
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• 2000

The authors aim at presenting a presumably new transformation formula involving generalized hypergeometric series by making use of series rearrangement technique which is one of the most effective methods for obtaining generating functions or other identities associated with (especially) the hypergeometric series. They also consider a couple of interesting special cases of their main result.

• Journal of the Chungcheong Mathematical Society
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• v.26 no.1
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• pp.111-123
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• 2013

Cameron and Storvick discovered change of scale formulas for Wiener integrals on classical Wiener space. Yoo and Skoug extended this result to an abstract Wiener space. In this paper, we investigate a change of scale formula for generalized Wiener integrals of various functions using the generalized Fourier-Feynman transform.

• The Pure and Applied Mathematics
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• v.18 no.4
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• pp.345-351
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• 2011

Taylor's formula is a powerful tool in analysis. In this study, we assume that an operator is m-times Fr$\acute{e}$chet-differentiable and satisfies a Lipschitz condition. We then obtain some Taylor formulas using only the Lipschitz constants. Applications are also provided.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.3
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• pp.138-146
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• 2013

Tetrapod, one of the famous armor blocks for rubble mound breakwaters, has been widely used in the world. In order to evaluate the required weight of Tetrapod, many researchers have proposed various stability formulas. Since the stability formulas were proposed by curve-fitting the experimental data, some uncertainties are included in the formulas. The main uncertainties are associated with experimental data, derivation of the formula, and variability of the design variables. In this study, a new stability formula is developed by using M5' model tree, which reduces the uncertainty in the derivation of the formula. The index of agreement is used to evaluate the performance of the developed formula. The index of agreement for the new formula is higher by about 0.1 than the previous formula. The performance of the previous formula was not good when the predicted stability number is greater than about 3.0. However. the new formula is accurate regardless of the magnitude of stability number. As a result, the new formula performs better than the previous formula, while expressed in the form of a tree but still in an explicit form.

• Child Health Nursing Research
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• v.1 no.1
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• pp.37-46
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• 1995

The effects of different discharge packs on the rate of breast-feeding practice were investigated in 2, 4 and 8 postpartal weeks. The subjects were those who have made delivery at Chonnam University Hospital from Jan to Feb 1994. They were divided into three groups by the discharge pack provided at the nursery room : the one group was given with formula discharge pack, another with breast-feeding discharge pack and the other nothing. The formula discharge pack contained formula samples, a feeding bottle and a pamphlet prepared by a formula company, and breast-feeding discharge pack contained a manual pump and a pamphlet made by Korean Nurses Association. Following results were obtained : 1. Different discharge packs significantly affected the rate of breast-feeding practice at 2 week postpartum, while not at 4 and 8 week postpartum. 2. At 2 week postpartum, the rate of breast-feeding practice was significantly higher in the group given with breast-feeding discharge pak than in that given with formula discharge pack. It was also significantly higher in the group given with breast-feeding discharge pack compared with the group given nothing. The breast feeding rate, however, did not significantly differ between the formula discharge pack group and the group given nothing. 3. The most common cause for the artificial feeding was 'lacking breast milk'. The most common cause to select a specific brand of formula milk was 'the same as in the nursery room'. In conclusion, it is suggested that encouraging mothers to perform breast feeding and providing them with a breast-feeding discharge pack instead of a formula pack at the nursery room are helpful in promoting the breast-feeding.