• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.7 no.3
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• pp.15-22
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• 2011

The chemistry factor and RTPTS margin for domestic reactor pressure vessel materials were analyzed by using the surveillance data which have been obtained from 8 nuclear power plants in Korea. The surveillance data have been used to assess the integrity of the pressure vessel under the pressurized thermal shock (PTS) event. The chemistry factor, which is determined by the Cu and Ni contents of vessel materials, is considered a proper tool to assess the $RT_{PTS}$. The chemistry factors, which were obtained from the surveillance data of domestic reactor pressure vessels, were investigated and compared with those of Regulatory Guide 1.99 in this study. Regressions for ${\Delta}RT_{NDT}$ were performed to expect the chemistry factor as a function of Cu and Ni, and to estimate $RT_{PTS}$ margin. The margin analysis was performed by comparing the regression graphs and standard deviations with those of Regulatory Guide 1.99. The standard deviations calculated by using the domestic surveillance data for base metal and welds are almost same as the standard deviations which are suggested on Regulatory Guide 1.99, Rev.2.

• Korean Journal of Occupational Health Nursing
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• v.13 no.2
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• pp.89-103
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• 2004

One of the major health problems of working women is job stress according to many studies. However, existing job stress questionnaires are suitable for men and men's job environments only, and do not reflect emotional labor for sales people. The aim of this research is to find women's job stress factors. The subjects of this investigation are married working women in sales since they experience emotional labor in addition to physical and psychological labor and the work-family conflict is very important job stressor for them. The job stressor of married sales women was analyzed through qualitative research. After I had in-depth interviews with 20 married sales women, I identified 49 new concepts, 3 main categories and 17 sub categories. The results are like the following. 1. 3 main categories are job factor, aggravate factor, and compensate factor. 2. Job factor has 5 sub-categories including 'increasing of selling', 'emotional labor' and 'physical burden'. 3. Aggrabate factor has 6 sub-categories including 'work/family conflict', 'relationship with higher office' and 'relationship with a fellow worker' 4. Compensate factor has 6 sub-categories including 'opportunity of employment', 'discrimination', and 'prestige' Consequently this study newly found some major job stressors for married working women in sales department.

• Journal of Climate Change Research
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• v.9 no.1
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• pp.69-74
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• 2018

The purpose of this study is to suggest the methodology of $CO_2$ Emission Factor Verification and Quantitative Assessment in Ethylene Product Processes. At first, this study compare the IPCC (Intergovernmental Panel on Climate Change) 1996 Guideline and 2006 Guideline. And analyse methodology for estimating $CO_2$ emission and $CO_2$ emission factor in Ethylene product process. Also analyse cases of estimating $CO_2$ emission factor based on material balance. Methodology of $CO_2$ Emission Factor Verification and Quantitative Assessment are following the categories proposed by GIR (Greenhouse Gas Inventory and Research Center). There are total 12 factors in 8 categories and give 5 or 10 points according to their importance. Also this study suggests necessary data of document to meet the conditions. The result would help estimate accuracy Greenhouse Gas Inventory. Also contribute to establish policy on environmental assessment, air conservation, etc.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.10
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• pp.906-910
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• 2008

$(K_{0.5}Na_{0.5})NbO_3$ (NKN) ceramics doped with $Li_{2}CO_3$ as sintering aids were manufactured in order to develop the low temperature sintering ceramics for piezoelectric device. The sintering aids were proved to lower the sintering temperature of doped NKN ceramics due to the effect of $Na_{2}CO_{3}-Li_{2}CO_3$ liquid phase. All the specimens showed the orthorhombic phase without secondary phase. And also, the piezoelectric properties of specimens were improved with increasing $Li_{2}CO_3$ contents. At sintering temperature of $930^{\circ}C$, the density, electromechanical coupling factor (kp), mechanical quality factor (Qm) and dielectric constant(${\epsilon}_{\gamma}$), piezoelectric constant of 0.3 wt.% $Li_{2}CO_3$ added specimen showed the optimum values of $4.255 g/cm^3$, 0.37, 234, 309, 136 pC/N, respectively.

• Biomolecules & Therapeutics
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• v.30 no.6
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• pp.570-575
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• 2022

Stress breaks body balance, which can cause diverse physiological disorders and worsen preexisting diseases. However, recent studies have reported that controllable stress and overcoming from stress reinforce resilience to resist against more intense stress afterwards. In this study, we investigated the protective effect of corticosterone (CORT), a representative stress hormone against hydrogen peroxide (H₂O₂)-induced neuronal cell death and its underlying molecular mechanism in SH-SY5Y cells, a human neuroblastoma cell line. The decreased cell viability by H₂O₂ was effectively restored by the pretreatment with low concentration of CORT (0.03 μM for 72 h) in the cells. H₂O₂-increased expression of apoptotic markers such as PUMA and Bim was decreased by CORT pretreatment. Furthermore, pretreatment of CORT attenuated H₂O₂-mediated oxidative damages by upregulation of antioxidant enzymes via activation of nuclear factor erythroid 2-related factor 2 (Nrf2). These findings suggest that low concentration of CORT with eustressed condition enhances intracellular self-defense against H₂O₂-mediated oxidative cell death, suggesting a role of low concentration of CORT as one of key molecules for resilience and neuronal cell survival.

• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3202-3205
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• 2023

The k₀-standardization neutron activation analysis method has successfully determined the mass fraction of elements of interest using around a hundred analytical radionuclides. However, several very short-lived nuclides with half-life less than 100 s have not been used at Dalat research reactor. One of the reasons is that the values of k₀-factors of these nuclides are significantly different. Therefore, this work focused on re-determination and evaluation of k₀-factors of very short-lived nuclides ¹¹⁰Ag (T_1/2 = 24 s) and ^46mSc (T_1/2 = 18.75 s). The results of determination of the short-lived nuclides revealed that k₀-factor of ¹¹⁰Ag is significantly difference between the existing data and the obtained results in this work. The evaluation of the k₀-factors was done by using the obtained results for application of k₀-NAA for NIST-1566b and NIST-2711A standard reference materials.

• Wind and Structures
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• v.30 no.3
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• pp.219-229
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• 2020

Net pressures on roofs and walls of buildings are dependent on the internal and external pressure fluctuations. The variation of internal and external pressures are influenced by the size and location of the openings. The correlation of external and internal pressure influences the net pressures acting on cladding on different parts of the roof and walls. The peak internal and peak external pressures do not occur simultaneously, therefore, a reduction can be applied to the peak internal and external pressures to obtain a peak net pressure for cladding design. A 1:200 scale wind tunnel model study was conducted to determine the correlations of external and internal pressures and effective reduction to net pressures (i.e., net pressure factors, F_C) for roof and wall cladding. The results show that external and internal pressures on the windward roof and wall edges are well correlated. The largest ${\mathcal{C}}_{{\check{p},net}$, highest correlation coefficient and the highest F_C are obtained for different wind directions within 90° ≤ θ ≤ 135°, where the large openings are on the windward wall. The study also gives net pressure factors F_C for areas on the roof and wall cladding for nominally sealed buildings and the buildings with a large windward wall opening. These factors indicate that a 5% to 10% reduction to the action combination factor, K_C specified in AS/NZS 1170.2(2011) is possible for some critical design scenarios.

• Geomechanics and Engineering
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• v.29 no.5
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• pp.487-496
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• 2022

Most of the pile's vertical static load tests in construction sites are the proof load tests, which is difficult to accurately estimate the ultimate bearing capacity and analyze the reliability of piles. Therefore, a reliability analysis method based on the proof load-settlement (Q-s) data is proposed in this study. In this proposed method, a simple ultimate limit state function based on the hyperbolic model is established, where the random variables of reliability analysis include the model factor of the ultimate bearing capacity and the fitting parameters of the hyperbolic model. The model factor M = R_uR / R_uP is calculated based on the available destructive Q-s data, where the real value of the ultimate bearing capacity (R_uR) is obtained by the complete destructive Q-s data; the predicted value of the ultimate bearing capacity (R_uP) is obtained by the proof Q-s data, a part of the available destructive Q-s data, that before the predetermined load determined by the pile test report. The results demonstrate that the proposed method can easy and effectively perform the reliability analysis based on the proof Q-s data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.9
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• pp.2290-2299
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• 2009

This study aims to analyze the importances of various SCM adoption factors suggested in precedent researches with AHP. SCM adoption factors were categorized by four types: organization factor, transaction factor, relation factor, and information factor. Each factor has sub-factors. Organization factor has five sub-factors: adoption strategy, support of CEO, maturity of information technology, development of assessment system, and innovation leadership. Transaction factor has three sub-factors: transaction period, delivery/quality, and shared goal. Relation factor has five sub-factors: trust, collaboration, inter-dependence, conflict, and immersion. Information factor has three sub-factors: information quality, information share, and information exchange. There are sixteen sub-factors altogether. Analyzing the importances of SCM adoption factors with AHP, the importance of organization factor(.387) ranked the highest. Relation factor(.291), information factor(.167), and transaction factor(.155) followed. Putting the analysis results of primary hierarchy factors and secondary hierarchy factors together, support of CEO(.169) ranked the highest and trust(.124), adoption strateg (.089), share goal(.081), information exchange(.069), collaboration(.064), and information share (.057) followed.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.30 no.2
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• pp.163-173
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• 2020

Objectives: The study was evaluated exposure variation and daily absorption level of cadmium, lead concentration of ambient air of monthly data from 1999 to 2017 for main exposure factor in outdoor workers. Methods: Based on the monthly data from 'The annual report of air quality in Korea from 1999 to 2018' in 'Air Korea' website in the Korean Ministry of Environment. The monthly data of PM_2.5, PM₁₀, cadmium, lead concentration of ambient air were recalculated to average, minimum, and maximum. And these data were combined to Asian-dust exposure data from 'The annual report of Asian-dust·smog in 2017' of National Institute of Meteorological Sciences in Korea. Results: Geometric mean(minimum-maximum) concentration in ambient air of monthly data were 0.0017 (ND-0.2015) mg/㎥ in cadmium and 0.0467(ND-0.8554) mg/㎥ in Pb from 1999 to 2017. Both of Cd and Pb concentration in ambient air showed the highest concentration in January and the lowest in August among annual variation from 1999 to 2017. PM₁₀ and PM_2.5 level showed the highest in March(PM₁₀) and February (PM_2.5) the lowest in August both of PM₁₀ and PM_2.5. Discussion: Based on exposure data and prior reports, daily Cd absorption was estimated to 0.013(ND-1.511) mg/day from respiration and 1.89 mg/day from daily food(25.2 mg/day of daily Cd intake). In case of Pb, daily absorption was estimated to 0.350(ND-6.416) mg/day from respiration and 1.38-1.71 mg/day from daily food intake. Conclusion: Cd and Pb with Asian-dust have high influential factor to increase the Cd and Pb exposure at Winter and Spring season in outdoor workers.