• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.2
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• pp.197-207
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• 2002

Energy dissipation capacity and earthquake responses of steel structures installed with unbonded braces(UB) were investigated. Parametric studies were performed for a single-degree-of-freedom structure under harmonic loads, and optimum yield strength of unbonded braces were derived. Nonlinear dynamic time history analyses were carried out to investigate the seismic response of multi-story model structures with UB having various size and strength. Various techniques were applied to determine proper story-wise distribution of UB in multi-story structures. The analysis results show that the maximum displacements of structures generally decrease as the stiffness of UB increases. However for some natural frequencies and seismic loads the maximum displacement and accumulated damage increases as the stiffness of UB increases.

• Fibers and Polymers
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• v.5 no.2
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• pp.89-94
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• 2004

N-Vinylcarbazole (VCZ) was solution-polymerized in tetrahydrofuran (THF) at 25, 35, and $45^{\circ}C$ using a room temperature initiator, 2,2'-azobis(2,4-dimethylvaleronitrile) (ADMVN); the effects of amount of solvent, polymerization temperature, and initiator concentration were investigated. On the whole, the experimental results corresponded to predicted ones. Room polymerization temperature using ADMVN proved to be successful in obtaining poly(N-vinylcarbazole) (PVCZ) of high molecular weight with small temperature rise during polymerization, nevertheless of free radical polymerization by azoinitiator. The polymerization rate of VCZ in THF was proportional to the 0.47 power of ADMVN concentration. The molecular weight was higher and the molecular weight distribution was narrower with PVCZ polymerized at lower temperatures. For PVCZ prepared in THF at $25^{\circ}C$ using ADMVN concentration of 0.00005 mol/mol of VCZ, weight-average molecular weight of 221,000 was obtained, with polydispersity index of 2.05, and degree of lightness converged to about 99%.

• Journal of Families and Better Life
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• v.8 no.2
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• pp.119-134
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• 1990

The purpose of this study were to investigate; The contact of housewives with governmental public advertisement about the energy conservation, general tendency about the energy conservation consciousness and behavior. For these purposed, a survey was conducted using questionnaires. Data analysis were conducted from 367 housewives with children in Seoul. Used statistical method were Frequency Distribution, percentile, Mean, one Way Anova, t-test, F-test, Pearson's Correlation, Multiple regression Analysis and Path Analysis. Major findings are as follows. 1) Level of public advertisement contact was low. In contrast to , level of energy conservation consciousness, consciousness change, and behavior was adequately high. 2) Statistically significant difference were found in advertisement contact according to the husband's age , Energy conservation consciousness change according to husband's occupation, and energy conservation behavior according to family life cycle. 3) Energy conservation consciousness changes were increased by advertisement contact. Energy conservation behaviors were increased by conservation consciousness and the degree of conservation consciousness change. 4) Governmental public advertisement about the energy conservation has both direct and indirect effect on the energy conservation behavior. From these finds, the following suggestions are made. Governmental effort about the energy conservation advertisement is needed to be activated. And the implications for the future study was need to incorporate the psychological variables in energy conservation study.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.31-32
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• 2011

Granulated slag from metal industries and fly ash from the combustion of coal are industrial by-products that have been widely used as mineral admixtures in normal and high strength concrete. Due to the reaction between calcium hydroxide and fly ash or slag, the hydration of concrete containing fly ash or slag is much more complex compared with that of Portland cement. In this paper, the production of calcium hydroxide in cement hydration and its consumption in the reaction of mineral admixtures is considered in order to develop a numerical model that simulates the hydration of concrete containing fly ash or slag. The heat evolution rates of fly ash- or slag-blended concrete is determined by the contribution of both cement hydration and the reaction of the mineral admixtures. Furthermore, the temperature distribution and temperature history in hardening blended concrete are evaluated based on the degree of hydration of the cement and the mineral admixtures. The proposed model is verified through experimental data on concrete with different water-to-cement ratios and mineral admixture substitution ratios.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.388-390
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• 2005

In this paper, a new rehabilitation training system was developed to improve equilibrium sense by combining virtual reality technology with a fixed exercise bicycle. The subjects consisted of two groups. A group of young people, was compared against a group of elderly. We measured three different running modes of virtual bicycle system with two successive sets. The parameters measured were running time, velocity, the weight movement, the degree of the deviation from the road, and the variables about the center of pressure. The repeated training, our results showed that the running capability of the elderly improve compared, In addition, it was found out that the ability of postural control and the equilibrium sense was improved with the presentation of the visual feedback information of the distribution of weight. From the results of this experiment, we showed that our newly developed system might be useful in the diagnosis of equilibrium sense or in the improvement of the sense of sight and, somatic, and vestibular sense of the elderly in the field of rehabilitation training.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.27-27
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• 2010

The exact partial discharge pulse should be measured in order to estimate the discharge source in the solid insulation and diagnose the degree of deterioration. Partial discharges generated in the insulation occur in the internal voids or at the edge of the insulation, have unique characteristics following the type and location. When external voltage is applied, Partial discharges occurred in the restrictively presented voids increase the quantity of electrical charge at the discharge onset voltage. The discharge characteristics have remained constant as space is filled by the impurity such as a compound of gases accompanied with discharge. In this study, How to design the insulation about the problems of the built-in diagnostics in the transformer is discussed by the interpretation of electric field.

• Research in Community and Public Health Nursing
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• v.29 no.3
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• pp.279-289
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• 2018

Purpose: This study has been conducted to identify factors that influence the initiation of treatment after the diagnosis of Korean patients with HIV. Methods: A cross-sectional study design was used, and 290 patients with HIV from outpatient departments of 7 hospitals participated. Self-report questionnaires included items on the days from the primary diagnosis to the initiation of treatment, and the patients' demographic and disease related characteristics. Negative binomial regression model (NBR) was utilized to determine risk factors influencing the initiation of treatment after the diagnosis of the patients with HIV. Results: The skewness of days was 6.62, and the degree of asymmetry of distribution was severe. In NBR, patients who were in their 40s and 50s, female, unmarried and living with their family, jobless, in a middle or high level of economic status, and diagnosed before 2014 showed a higher risk of delayed treatment than patients who were younger, male, married and living with family, in a low level of economic status, and diagnosed in 2014 or afterwards. Conclusion: The findings suggest the necessity of intervention to promote HIV patients' early entry into treatment based on the participants' characteristics.

• Magazine of the Korea Concrete Institute
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• v.2 no.3
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• pp.65-72
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• 1990

Theoretical expressions were dcrived for the numher of fibers per unit cross-sectional area in fiber reinforced concrete, with due consideration given to the effects of the surrounding boundaries. The number of fibers per unit cross-sectional area in steel fiber reinforced concrete was also measured experimentally for the specimens incorporating various volume fractions of fibers of different types. Statistical evaluation of the measured value was then performed in order to assess the differences in fiber concentration at different location on tbe cross section. Degree of reorientation of steel fibers in concrete occuring during vibration was examined by com¬paring the differences in the computed and measur'ed values of the number of fibers per unit cross-sectional area.

• The Korean Journal of Ecology
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• v.10 no.3
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• pp.119-127
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• 1987

On the east slope of the front ranges of the Colorado Rockies, USA, three species of Populus are distributed at different elevations from the Great Plains to the timberline. At elevations 1, 720m (P. sargentii), 2, 335m (P.angustifolia) and 3, 190m (P.tremuloides) chlorophyll cotents of leaves of thses dioecious trees were determined. Total chlorophyll content was in the range of 0.86-1.56mg/g leaf, increasing with elevation as a second-degree polynomial, and the peak content was estimated to be reached at about 2, 800m. Total chlorophyll content was greater in female than in male trees in the two higher elevation species, but not in P. sargentii, the low elevation species. Chlorophyll b content was greater than chlorophyll a content in the same two higher elevation species. The increase of chlorophyll b than to increase of chlorophyll a content. These phenomena appear to be the result of adaptation of these species to different environmental conditional at different elevation. Sequential distribution of plant populations on environmental gradients in such a way that variation in given plant characters paralell the environmental gradient must occur not only in ecotypes of a species, but also in different but closely related species.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.37 no.6
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• pp.396-396
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• 2000

Three-Dimensional FDTD method is applied to analyze the dielectric resonator coupled with two microstrip lines. We model accurately the curved surface using Noriaki model. The frequency resolution is 106.46 MHz by the conventional FFT However it is not sufficient for determining its resonant frequency. So we introduce the Pad approximation and Stoer-Bulirsch method in order to have the high frequency resolution degree, 1.00 MHz. All results are compared with the measured data. As a result, we acquire the very precise result through the Pad approximation. And sinusoidal wave is applied. From the plot of the electric and magnetic field distribution, it is shown that the resonant mode is $TE_{01{\delta}}$ mode.