• Structural Engineering and Mechanics
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• v.52 no.4
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• pp.663-686
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• 2014

This paper deals with free vibration analysis of bidirectional functionally graded annular plates resting on a two-parameter elastic foundation. The formulations are based on the three-dimensional elasticity theory. This study presents a novel 2-D six-parameter power-law distribution for ceramic volume fraction of 2-D functionally graded materials that gives designers a powerful tool for flexible designing of structures under multi-functional requirements. Various material profiles along the thickness and in the in-plane directions are illustrated by using the 2-D power-law distribution. The effective material properties at a point are determined in terms of the local volume fractions and the material properties by the Mori-Tanaka scheme. The 2-D differential quadrature method as an efficient and accurate numerical tool is used to discretize the governing equations and to implement the boundary conditions. The fast rate of convergence of the method is shown and the results are compared against existing results in literature. Some new results for natural frequencies of the plates are prepared, which include the effects of elastic coefficients of foundation, boundary conditions, material and geometrical parameters. The interesting results indicate that a graded ceramic volume fraction in two directions has a higher capability to reduce the natural frequency than conventional 1-D functionally graded materials.

• Journal of applied mathematics & informatics
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• v.16 no.1_2
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• pp.419-427
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• 2004

In this paper we establish the Hajeck-Renyi type inequality and derive the strong law of large numbers for asymptotically quadrant sub-independent random variables.

• Nuclear Engineering and Technology
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• v.54 no.6
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• pp.2334-2337
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• 2022

Deuterium-tritium reaction is the most promising one in term of the highest nuclear fusion cross-section for the reactor. So it is one of urgent issues to develop materials and components that are simultaneously resistant to high heat flux and high energy neutron flux in realization of the fusion energy. 2.45 MeV neutron production was reported in D-D reaction in KSTAR and regarded as beam-target is the dominant process. The feasibility study of KSTAR to wide area neutron source facility is done in term of D-D and D-T reactions from the empirical scaling law from the mixed fast and thermal stored energy and its projection to cases of heating power upgrade and DT reaction is done.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.142-146
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• 2008

Titanium silicalite-1 catalyst was prepared using a $SiO_2-TiO_2$ xerogel and applied to allylchloride (ALC) epoxidation by $H_2O_2$ as oxidant in a batch reactor. The reaction temperature was varied from 25 to $55^{\circ}C$, and the concentrations of ALC and $H_2O_2$ were changed from 0.2 to 3 M and from 0.2 to 1.5 M, respectively. The kinetic data obtained were applied to the power rate law, Eley-Rideal, and a Langmuir-Hinshelwood model, and power rate law fits the experimental data best. Activation energy was 27.9 kJ/mol, and the reaction orders with respect to $H_2O_2$ and ALC were determined to be 0.41 and 0.52, respectively.

• Journal of applied mathematics & informatics
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• v.28 no.3_4
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• pp.1025-1034
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• 2010

Let {$X_n$, $n\;{\in}\;\mathbb{Z}_+^d$} be a field of identically distributed and negatively associated random variables with mean zero and set $S_n\;=\;{\sum}_{k{\leq}n}\;X_k$, $n\;{\in}\;\mathbb{Z}_+^d$, $d\;{\geq}\;2$. We investigate precise asymptotics for ${\sum}_n|n|^{r/p-2}P(|S_n|\;{\geq}\;{\epsilon}|n|^{1/p}$ and ${\sum}_n\;\frac{(\log\;|n|)^{\delta}}{|n|}P(|S_n|\;{\geq}\;{\epsilon}\;\sqrt{|n|\log|n|)}$, ($0\;{\leq}\;{\delta}\;{\leq}\;1$) as ${\epsilon}{\searrow}0$.

• Journal of Environmental Science International
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• v.14 no.7
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• pp.711-717
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• 2005

A magenta azomethine dye(D) was synthesized from the reaction of 3-methyl-1-phenyl-2-pyrazoline-5-one with N,N-diethyl-1,4-phenylenediamine. The magenta azomethine dye was identified on the basis of elemental analysis, $^{13}C-NMR$, infrared, and GC/MS studies. The magenta azomethine dye was decomposed in a basic solution. Rate constants of the fading reaction of magenta azomethine dye in ethanol-water solvent were measured spectrophoto­metrically at 540 nm. Reaction rate was increased with the increase of $[OH\^{-}]\;and\;[H\_{2}O]$ in the region of $[H_{2}O]=11\~40\;M$. The reaction was governed by the following rate law. -d[D]/dt = $\{k_o\;+\;k_{OH}[OH^-][H_{2O}]\}[D]$ A possible mechanism consistent with the empirical rate law has been proposed.

• Journal of Korean Public Health Nursing
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• v.29 no.2
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• pp.312-324
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• 2015

Purpose: This study addressed the relationship among nutritional risk, stress, and health related quality of life for older women with a foreign daughter-in-law. Methods: A descriptive research design was used for this study. The subjects of this study were 112 older women with a foreign daughter-in-law all of whom were over 65 years and living in D city. Personal interview was used for data collection. Nutritional risk, stress, and health related quality of life were measured using Nutrition Screening Initiative (NSI), Family Inventor of Life Events and Changes (FILE), and Medical Outcome Study (MOS) Short-form 36-Item Health Survey (SF-36), respectively. Results: Older women with a foreign daughter-in-law showed negative correlation between quality of life related health and nutritional risk, stress and age, and positive correlation between Activities of Daily Living (ADL); 46% of variance in health related quality of life of older women with a foreign daughter-in-law was explained by nutritional risk, ADL, stress and occupation. Conclusion: Based on the results of this study, we suggested that specialized programs should be established to help in development of social relationship networks for older women who have a foreign daughter-in-law.

• Structural Engineering and Mechanics
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• v.5 no.6
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• pp.743-754
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• 1997

A three-dimensional constitutive modeling for reinforced concrete is presented for finite element nonlinear analysis of reinforced concrete. The targets of interest to the authors are columns confined by lateral steel hoops, RC thin shells subjected to combined in-plane and out-of-plane actions and massive structures of three-dimensional (3D) extent in shear. The elasto-plastic and continuum fracture law is applied to pre-cracked solid concrete. For post cracking formulation, fixed multi-directional smeared crack model is adopted for RC domains of 3D geometry subjected to monotonic and reversed cyclic actions. The authors propose a new scheme of decomposing stress strain fields into sub-planes on which 2D constitutive laws can be applied. The proposed model for 3D reinforced concrete is experimentally verified in both member and structural levels under cyclic actions.

• 발명특허
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• v.16 no.2 s.180
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• pp.40-43
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• 1991

• 발명특허
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• v.16 no.3 s.181
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• pp.43-46
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• 1991