• Journal of the Korean Home Economics Association
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• v.30 no.3
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• pp.325-345
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• 1992

The purpose of this study was to investigated the imfluences of family life cycle stages and perception of housework's value on perceived time pressure and role conflict in housewife-teachers. The subjects of this study were 329 married women teachers that teach in junior or senior high schools in Taegu. A questionaire was used as the survey method and for the method of data analysis, factor analysis, MANOVA, and Scheff test as a post-hoc analysis. The major findings were as follows: 1) There were significant interaction effects of family life cycle stages and perception of housework's value on perceived time pressure and role conflict. 2) The main effect for family life cycle stages was significant. 3) Followup univariate F-tests revealed significant mean differences for marital, parental and homemaker's role conflict.

• Korean Journal of Mathematics
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• v.25 no.2
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• pp.279-301
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• 2017

An L(3, 2, 1)-labeling for the graph G = (V, E) is an assignment f of a label to each vertices of G such that ${\mid}f(u)-f({\upsilon}){\mid}{\geq}4-k$ when $dist(u,{\upsilon})=k{\leq}3$. The L(3, 2, 1)-labeling number, denoted by ${\lambda}_{3,2,1}(G)$, for G is the smallest number N such that there is an L(3, 2, 1)-labeling for G with span N. In this paper, we compute the L(3, 2, 1)-labeling number ${\lambda}_{3,2,1}(G)$ when G is a cylindrical grid, which is the cartesian product $P_m{\Box}C_n$ of the path and the cycle, when $m{\geq}4$ and $n{\geq}138$. Especially when n is a multiple of 4, or m = 4 and n is a multiple of 6, then we have ${\lambda}_{3,2,1}(G)=11$. Otherwise ${\lambda}_{3,2,1}(G)=12$.

• Nuclear Engineering and Technology
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• v.43 no.1
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• pp.83-88
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• 2011

To define the effect of strain rate variation from 0.04% to 0.004%/s on environmental fatigue of CF8M cast stainless steel, which is used as a primary piping material in nuclear power plants, low-cycle fatigue tests were conducted at operating pressure and temperature condition of a pressurized water reactor, 15 MPa and $315^{\circ}C$, respectively. A high-pressure and high-temperature autoclave and cylindrical solid fatigue specimens were used for the strain-controlled low-cycle environmental fatigue tests. It was observed that the fatigue life of CF8M stainless steel is shortened as the strain rate decreases. Due to the effect of test temperature, the fatigue data of NUREG-6909 appears a slightly shorter than that obtained by KEPRI at the same stress amplitude of $1{\times}10^3$ MPa. The environmental fatigue correction factor $F_{en}$'s calculated with inputs of the test data increases with high strain amplitude, while the $F_{en}$'s of NUREG-6909 remain constant regardless of strain amplitude.

• Journal of Electrical Engineering and Technology
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• v.7 no.2
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• pp.207-211
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• 2012

Spinel-$Li_4Ti_5O_{12}$ was successfully synthesized by a solid-phase method at 800, 850, and $900^{\circ}C$ according to the $Li_4Ti_5O_{12}$ cubic spinel phase structure. To achieve higher EDLC energy density with the $Li_4Ti_5O_{12}$, the negative electrode of the hybrid supercapacitor was studied in this work. The electrochemical performances of the hybrid supercapacitor and EDLC were characterized by constant current discharge curves, c-rate, and cycle performance testing. The capacitance (1st cycle) of the hybrid supercapacitor and EDLC was 209 and 109 F, respectively, which is higher than EDLC. The capacitance of the hybrid supercapacitor decreases from 209 F to 101 F after 20 cycles when discharged at several specific current densities ranging from 1 to 10 A. In contrast, capacitance of the EDLC hardly decreases after 20 cycles. Results show that hybrid supercapacitor benefits from the high rate capability of supercapacitor and high capacity of the battery. Findings also prove that the hybrid supercapacitor is an energy storage device where the supercapacitor and the Li ion secondary battery coexist in one cell system.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.456-462
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• 2018

The purpose of this study was to assess cross-generational effects of bisphenol A exposure in benthic copepods, Tigriopus west. Nauplii (<24 hours old) were exposed to graded concentrations of bisphenol A, and toxicity end-points such as survival, development, sex ratio, and fecundity were measured. $F_1$ generations were grown under innoxious conditions, and similarly assessed. Significant differences were observed in development of nauplii and copepodites, between exposed and non-exposed copepods; however, there were no differences in survival of nauplii or copepodites, sex ratio, or brooding rate in parental generation. In contrast, in the $F_1$ generation, there were significant differences between the control group and exposed group in survival and development of nauplii. Length, width, and biomass of parental and $F_1$ generations were reduced in the exposed group compared to the control group. In addition, some deformities, such as swelling of the prosome, abnormally shaped egg sac, and dwarfism were observed after exposure to bisphenol A. So, our study demonstrates that a cross-generation toxicity test and monitoring of morphological deformities in harpacticoid copepods, can be useful for development of potential bioindicators for environmental monitoring, and assessment of chemical impact.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.142-142
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• 2001

• Proceedings of the Korean Society of Life Science Conference
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• 2004.10a
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• pp.19-21
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• 2004

• Journal of Family Resource Management and Policy Review
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• v.11 no.1
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• pp.65-81
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• 2007

The purpose of this study is to analyze income and consumption expenditure patterns over the family life cycle. The data used in this study is the 2004 Survey data from the Annual Report on the Family Income and Expenditure Survey data which are included salary and wage earners' households living in urban areas. The income and expenditure data of 20,383 households are analyzed. The family life cycle is classified into six stages and the items of expenditure are classified into 12 categories. The data are analyzed by descriptive statistics, $X^2$ test, F-test, and Duncan's multiple range test using SAS 8.0 package program. The major findings of this study are as fellows: First, the average monthly family income of the total sample is 3,480,000 won. The proportion of regular and irregular income among the total family income is 95.5% and 4.5% respectively. Second, the amount and ratio of monthly regular income fur each category are significantly different over the family life cycle. Third, the average monthly family expenditure of the total sample is 2,250,000 won. The amount and ratio of monthly expenditure of all items are significantly different over the family life cycle. The highest expenditure item is the traffic expanse and phone charge.

• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.383-388
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• 2007

A (g, f)-factor F of a graph G is Called a Hamiltonian (g, f)-factor if F contains a Hamiltonian cycle. The binding number of G is defined by $bind(G)\;=\;{min}\;\{\;{\frac{{\mid}N_GX{\mid}}{{\mid}X{\mid}}}\;{\mid}\;{\emptyset}\;{\neq}\;X\;{\subset}\;V(G)},\;{N_G(X)\;{\neq}\;V(G)}\;\}$. Let G be a connected graph, and let a and b be integers such that $4\;{\leq}\;a\;<\;b$. Let g, f be positive integer-valued functions defined on V(G) such that $a\;{\leq}\;g(x)\;<\;f(x)\;{\leq}\;b$ for every $x\;{\in}\;V(G)$. In this paper, it is proved that if $bind(G)\;{\geq}\;{\frac{(a+b-5)(n-1)}{(a-2)n-3(a+b-5)},}\;{\nu}(G)\;{\geq}\;{\frac{(a+b-5)^2}{a-2}}$ and for any nonempty independent subset X of V(G), ${\mid}\;N_{G}(X)\;{\mid}\;{\geq}\;{\frac{(b-3)n+(2a+2b-9){\mid}X{\mid}}{a+b-5}}$, then G has a Hamiltonian (g, f)-factor.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.2
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• pp.424-435
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• 1991

To develop the photoelastic experiment method for the orthotropic material under pure torsional moment is the main objective of this research. In the development of photoelastic experiment for orthotropic material under pure torsional moment, the important problems and their solutions are the same as following. In the model material for photoelastic experiment, it was found that C.F.E.C.(Copper Fiber Epoxy Composite) can be used as the model material of photoelastic experiment for orthotropic material. In the stress freezing cycle, it was assured that stress freezing cycle for epoxy can be used as the stress freezing cycle of the photoelastic experiment for orthotropic material. In the slicing method, it was found that the negative oblique slicing method can be effectively used as slicing method in 3-dimensional photoelastic experiment. In the measuring method of stress fringe values and physical properties in the high temperature, it was found that stress fringe values can be directly measured by experiment and physical properties can be directly or indirectly by equation between stress fringe values and physical properties developed by author. In the stress analysis method of orthotropic material under pure torsional moment by photoelastic experiment, it will be studied in the second paper.