• Advances in environmental research
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• 제3권4호
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• pp.367-377
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• 2014

In this study, we investigated a life cycle assessment (LCA) of six roof-waterproofing systems [asphalt (C1), synthetic polymer-based sheet (C2), improved asphalt (C3), liquid applied membrane (C4), Metal sheet with asphalt sheet (N1), and liquid applied membrane with asphalt sheet (N2)]for reinforced concrete building using an architectural model. To acquire accurate and realistic LCA results, minimum units of material compositions for life cycle inventory and real data for compositions of waterproofing materials were used. Considering only materials and energy demands for waterproofing systems per square meter, higher greenhouse gas (GHG) emissions could be generated in the order of C1 > N2 > C4 > N1 > C2 > C3 during construction phase. However, the order was changed to C1 > C4 > C3 > N2 > N1 > C2, when the actual architecture model was applied to the roof based on each specifications. When an entire life cycle including construction, maintenance, and deconstruction were considered, the amount of GHG emission was in the order of C4 > C1 > C3 > N2 > C2 > N1. Consequently, N1 was the most environmental-friendly waterproofing system producing the lowest GHG emission. GHG emissions from maintenance phase accounted for 71.4%~78.3% among whole life cycle.

• 한국정밀공학회지
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• 제13권12호
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• pp.70-77
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• 1996

Fatigue tests were carried out at high temperature on a Cr-Mo-V steel in order to assess the fatigue life of components used in power plants. The characteristics of high temperature fatigue were divided in terms of cycle-dependent fatigue and time-dependent fatigue, each crack propagation rate was examined with respect to fatigue J-integral range, .DELTA. J$_{f}$and creep J-integral range, .DELTA. J$_{c}$. The fatigue life was evaluated by analysis of J-integral value at the crack tip with a dimensional finite element method. The results obtained from the present study are summarized as follows : The propagation characteristics of high temperature fatigue cracks are determined by .DELTA. J$_{f}$for the PP(tensile plasticity-compressive plasticity deformation) and PC(tensile plasticity - compressive creep deformation) stress waveform types, and by .DELTA. J$_{c}$for the CP(tensile creep- compressive plasticity deformation) stress waveform type. The crack propagation law of high temperature fatigue is obtained by analysis of J-integral value at the crack tip using the finite element method and applied to examine crack propagation behavior. The fatigue life is evaluated using the results of analysis by the finite element method. The predicted life and the actual life are close, within a factor of 2.f 2.f 2.

• Corrosion Science and Technology
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• 제17권5호
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• pp.211-217
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• 2018

Natural degradation of grounding-electrode in soil environment should be monitored for several decades to predict the lifetime of the grounding electrode for efficient application and management. However, long-term studies for such electrodes have many practical limitations. The conventional accelerated corrosion test is unsuitable for such studies because simulated soil corrosion process cannot represent the actual soil environment. A preliminary experiment of accelerated corrosion test was conducted using existing test standards. The accelerated corrosion test that reflects the actual soil environment has been developed to evaluate corrosion performances of grounding-electrodes in a short period. Several test conditions with different chamber temperatures and salt spray were used to imitate actual field conditions based on ASTM B162, ASTM B117, and ISO 14993 standards. Accelerated degradation specimens of copper-bonded electrodes were made by the facile method and their corrosion performances were investigated. Their corrosion rates were calculated to $0.042{\mu}m/day$, $0.316{\mu}m/day$, and $0.11{\mu}m/day$, respectively. These results indicate that accelerated deterioration of grounding materials can be determined in a short period by using cyclic test condition with salt spray temperature of $50^{\circ}C$.

• 패션비즈니스
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• 제10권1호
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• pp.132-147
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• 2006

The purpose of this study is to provide for the basic data useful to the effective production and marketing of the foundation garment befitting adult women's shapes and preferences, and thereby, help them improve their apparel life. For this purpose, 563 Korean women aged between 20-59 were sampled to survey their recognition and actual wearing condition of foundation garments and positively identify the factors affecting the practices and thereupon, determine the correlations among them by age group. The raw data of this study is processed by SPSS Win(10.1) and analyzed by using frequency, percentage, $x^2$-test, ANOVA, Duncan-test. The most of adult women were aware of their foundation size and the absolute majority of them wore brassieres, while a half of them used the girdles. The adult women had 5.7 Brassieres and 2.2 Girdles. The use of the foundation depended much on user's age or seasons. They had begun to wear Brassieres at their age of 15 on an average and Girdle around their age of 19 depending their individual needs. It has been found through this study that adult women's is actual wearing condition of foundation garments differ by age group, which may well suggest that foundation production need to consideration this age-wise practices when setting up their foundation production and marketing strategies.

• 가정과삶의질연구
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• 제24권5호
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• pp.129-140
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• 2006

This study analyzed mothers' beliefs and practices for children's literacy acquisition by investigating the actual conditions of the literacy environment at home. The aim of this study is to understand what mothers believe about literacy, to recognize that children's literacy development is attained by activities done at home, and to provide basic data about parents' roles and guides for the development of a literacy education program for mothers and literacy development for children. As results of this study will show firstly that the actual conditions of the literacy environment for children at home begin before children are six months old, as most of mothers read to their children 2 or 3 times per week for more than 40-50 minutes. In addition, the study illustrate significant differences in mothers' literacy beliefs and practices according to the age of each child and the mothers educational background. A Third point that will be outlined is the way in which the developmental literacy belief among mothers' beliefs was related to the constructions and practices of mothers literacy environment. finally, the study will look at the influence of developmental literacy belief among mothers beliefs on practices of mothers literacy environments.

• 가정과삶의질연구
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• 제33권1호
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• pp.87-97
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• 2015

This study aims to examine how home child care allowance influences a mother's choice of child care type. To accomplish this goal, we surveyed 432 mothers who had at least one child under 5 years old. The data were analyzed by frequencies, percentages, means and binomial logistic regressions. The results showed that unemployed mothers and mothers with younger children had a high tendency to choose home child care allowance instead of child care subsidy. Second, mother's employment status, age of first child and an interactive term of mother's employment status and home child care receipt influenced a concordance between an ideal and actual child care type. Unemployed mothers and mothers with younger children were more likely to experience a concordance between their ideal and actual types of child care. By investigating how home child care allowance affects the right of choice in child care type, this study provides empirical information to policy makers and researchers and contributes to develop cash-benefit policies for families with young children.

• 한국주조공학회지
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• 제26권4호
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• pp.184-190
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• 2006

Presence of inclusions in Ti castings imparts detrimental effects on the mechanical performance of castings. However, actual inclusions do not occur very frequently and they are difficult to locate. As a result, acquirement of specimens for mechanical tests and thus in-depth research of the adverse influence of inclusions are challenging. To address this problem, artificial inclusion seeding methodology is developed to emulate actual inclusions in Ti investment castings. Firstly, to validate that this new methodology does not result in inherent mechanical property degradation, Ti specimens with machined, backfilled and HIPed holes are produced and compared to control (unaltered), cast Ti material. Fatigue test results indicate that this 'machine-and-HIP methodology without seeding' does not result in any fundamental mechanical property alteration, which would bias ensuing comparative results. Secondly, based on this result, validation of the artificially seeded inclusions being equivalent to 'as cast' inclusions is performed by comparing their fatigue behaviors. Test specimens created by the novel artificial inclusion seeding methodology are equivalent to Ti casting specimens containing actual cast-in inclusions, and an adverse effect of inclusions in investment castings is confirmed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.277-282
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• 2011

Bogie frame is typical safety part of railway vehicle. Total serviceable life of bogie frame will be evaluated by Cumulative Damage Approach Method that is defined by dynamic strain measurement during revenue service under the actual track conditions. As a result of the standardization process developed in British Standard Institution, BS 7608 defines for fatigue design and test method of steel structure by fatigue test results over the long period. This paper evaluates the total serviceable life applying BS 7608 for the bogie frame of Electric Multiple Unit to verify structural safety of the bogie frame.

• 한국농촌건축학회논문집
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• 제1권2호
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• pp.39-51
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• 1999

This study aims to obtain new design factors in terms of constructing rural apartment houses fit for the actual farm life. To carry out this study, field studies and personal interviews have been made on the living mode and using realities in the unit spaces of the rural apartment houses. The houses surveyed are the rural apartments in Chungbuk Province which were built by the public program to improve old farm houses. The results are as follows. The living modes .in the unit spaces of the rural apartments are very similar to those of the urban apartment houses. But compared with the urban indoor-living modes, the rural life is keeping more of the traditional sitting way-of-living. Accordingly, it is quite necessary to consider the nature of farm life and the sitting way-of-living in designing the rural apartment houses.

• 한국해양공학회지
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• 제12권2호통권28호
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• pp.71-78
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• 1998

In this report for the assessment of creep properties of high-temperature tube materials in power plants, the long-time($10^4$~105h) creep life prediction by ISM for 2.25Cr1Mo steel was studied. It was clarified experimentally and quantitatively that the newly developed long-time creep life prediction equation was very coincident with the actual experimental data with high confidence, and the model was $t_r=\alpha\varepsilon_0^{\beta}\sigma^{-1}$.