• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.392-404
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• 2019

The purpose of this study was to identify the impact of various income sources on income inequality of forestry households. Data from the Forestry Household Economy Survey from 2013-2016 were analyzed using the Gini coefficient decomposition method via income source. In particular, the income inequality analysis of forestry households was broken down into separate analyses based on group, i.e., the whole of forestry households and the five income quintile classes. The results of the analyses showed that income inequality of forestry households is primarily affected by forestry and nonforestry incomes and income quintile class. Moreover, income inequality of the highest income quintile class was largely affected by forestry income compared with other sources of income, whereas that of other income quintile classes was largely affected by nonforestry income. Therefore, in order to reduce income inequality in forestry households, it is necessary to increase the proportion of forestry income in the lower four quintile classes. Given that the income of the lowest quintile class is negative, it is necessary to devise ways to improve the proportion and quantity of forestry income. At the same time, as forestry income increases, a policy alternative is also required to improve inequality in forestry income.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.49 no.2
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• pp.95-106
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• 2021

Side-jets enable the immediate maneuver of a missile compared to control surfaces; however, they may cause adverse effects on aerodynamic coefficients, for they interfere with freestream. To find out the impact of side-jets on aerodynamic coefficients, we simulate side-jets as air gas and utilize multi-fidelity models to evaluate differences between aerodynamic coefficients obtained with and without side-jets. We computed differences in aerodynamic coefficients to investigate side-jet effects for the changes of a Mach number, a bank angle, and an angle of attack. As a result, asymmetrically developed side-jets affect the longitudinal force and moment coefficients, and the lateral force and moment coefficients drastically change in-between -30 and 30 degrees of bank angles. In contrast, side-jets hardly influence the axial force coefficients. As for the axial moment coefficient, we could not determine the side-jet effect due to a lack of aerodynamic coefficient samples in the Mach number. All in all, we confirm that side-jets lead to the change of a missile attitude as they considerably vary the longitudinal and lateral aerodynamic coefficients.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5B
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• pp.529-537
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• 2006

This paper investigates the impacts of the drag-related weighting coefficients on mean velocity and turbulence structures. The transport equations for the Reynolds stress of vegetated open-channel flows are derived by using the temporal- and horizontal-averaging scheme. It is found that the total Reynolds stress of vegetated open channel flows consists of the Reynolds stress due to temporally fluctuating velocities and the Reynolds stress due to spatially fluctuating velocities. The drag-related weighting coefficient $C_{fk}$ for the total Reynolds stress component is found to be unit, while the coefficient for the Reynolds stress due to temporally fluctuating velocities can be negligible. This is the reason why very small weighting coefficients in previous studies yield very good agreements with measured data. In other words, the Reynolds stress due to spatially fluctuating velocities remains still unknown, especially due to the large number of measuring locations. Through a developed Reynolds stress model, vegetated open-channel flows are simulated and compared with measured data from the literature. Comparisons reveal that the computed mean flow and Reynolds stress structures are hardly affected by the drag-related weighting coefficients. However, the computed turbulence intensity profiles are significant different with the drag-related weighting coefficients. A budget analysis of the transport equations for the Reynolds stress component is carried to investigate why turbulence intensity is affected by the drag-related weighting coefficients.

• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.5
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• pp.230-235
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• 2004

In this paper, epoxy elasticity factors were investigated by TMA (Thermomechanical Analysis), DMTA (Dynamic Mechanical Thermal Analysis) and FESEM (Field Emission Scanning Electron Microscope) to improve toughness and reduce brittleness of existing epoxy resin. Dumbbell shaped specimens were made and tested at rates of 0, 20 and 35phr (part per hundred resins). TMA temperatures ranged from -2$0^{\circ}C$ to 20$0^{\circ}C$. Tg (glass transition temperature) of elastic epoxy was measured by thermal analysis. Also investigated were thermal expansion coefficient ($\alpha$), modulus and Tan$\delta$ (loss factor). And we analyzed structure through FESEM, could find elastic-factors of elastic epoxy that is not existing-epoxy. In addition, we measured permittivity and Tan$\delta$ for investigation of the electrical properties of elastic epoxy. Permittivity and Tan$\delta$ depend on elastomer composition. Namely, permittivity and Tan$\delta$ increase according to the elastomer contents. For experimental analysis results, 20phr was considered an excellent specimen.

• Korean Journal of Occupational Health Nursing
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• v.21 no.2
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• pp.116-124
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• 2012

Purpose: This study was conducted to examine the influencing factors of social support, self efficiency and depression among the hearing-impaired and physically disabled on their job stress. Methods: The data were collected from Jan.1 to Aug. 30, 2010 from 151 disabled workers. The instruments for this study were the Korean Occupational Stress Scale (KOSS), Social Support Scale, General Self-Efficacy Scale and Beck Depression Inventory-Korean Version (K-BDI). The data were analyzed using t-test, Pearson correlation coefficient and multiple regression with the SPSS/WIN 18.0. Results: The physically disabled show higher social support (t=0.284, p= .001) and self efficacy (t=0.165, p= .024) but lower in depression (t=0.789, p<.001) than the hearing-impaired. There are negative correlation between job stress and social support, job stress and self efficacy but a positive correlation between job stress and depression. These three factors explained 42.9% of the variance in job stress. Conclusion: Social support and self efficacy have positive impacts on job stress but depression has negative impact.

• Korean Journal of Childcare and Education
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• v.13 no.1
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• pp.167-184
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• 2017

Objective: The gold of this study is to identify the correlation between mothers' rejective parenting attitude and children's humanity and adaptation to educational institutions, as well as to find out whether children's humanity could act as a mediating effect against mothers' rejective parenting attitude in the process of children's adapting to the institutions. Methods: The study was conducted on 259 children aged 4 to 5 and their mothers. The collected data were used to conduct Pearson correlation coefficient, Three-step mediated regression analysis, and the Sobel test using the SPSS 20.0 program. Results: First, children's institutional adaptability had a significant negative correlation only with 'mother's hostility'. Children's humanity had a significant positive correlation with their institutional adaptability. Second, mothers' hostile attitude had a direct or indirect impact on children's institutional adaptability. Conclusion/Implications: The results above suggest that children's good humanity and parents' friendly attitude are important in children's institutional adaptability.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.6
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• pp.95-107
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• 2020

By applying behavioral intention theories and the theory of diffusion of innovation in organizations, this study identified several factors influencing the intention to apply management accounting in enterprises in Vietnam. Research data was collected from the questionnaire sent to Vietnamese enterprises in 2019, collecting 542 observations from accountants and directors. The data is, then, synthesized by excel file, conformity check, and processed by SPSS 20 software with descriptive statistics and multiple regression analysis. The results showed four factors that affect the intention to apply management accounting in enterprises in Vietnam: (1) Performance expectancy; (2) Effort expectancy; (3) Perceived trust; and (4) Subjective norms. The study pointed out that the above factors explain 60.618% of the variation of "intention to apply management accounting", in which, Subjective norms has the strongest impact (regression coefficient is 0.238). The findings also show that raising the awareness of managers and accountants about the role of management accounting, improving the qualifications and knowledge of accountants, and increasing the trust of managers about management accounting information are needed to increase the level of management accounting application in Vietnamese enterprises. The study also proposes recommendations to improve the effectiveness of management accounting for managers in operation and decision-making.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.4
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• pp.291-302
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• 2017

Radiometric calibration is a prerequisite to quantitative remote sensing, and its accuracy has a direct impact on the reliability and accuracy of the quantitative application of remotely sensed data. This paper presents absolute radiometric calibration of the KOMPSAT-3 (KOrea Multi Purpose SATellite-3) and cross calibration using the Landsat-8 OLI (Operational Land Imager). Absolute radiometric calibration was performed using a reflectance-based method. Correlations between TOA (Top Of Atmosphere) radiances and the spectral band responses of the KOMPSAT-3 sensors in Goheung, South Korea, were significant for multispectral bands. A cross calibration method based on the Landsat-8 OLI was also used to assess the two sensors using near simultaneous image pairs over the Libya-4 PICS (Pseudo Invariant Calibration Sites). The spectral profile of the target was obtained from EO-1 (Earth Observing-1) Hyperion data over the Libya-4 PICS to derive the SBAF (Spectral Band Adjustment Factor). The results revealed that the TOA radiance of the KOMPSAT-3 agree with Landsat-8 within 5.14% for all bands after applying the SBAF. The radiometric coefficient presented here appears to be a good standard for maintaining the optical quality of the KOMPSAT-3.

• Journal of Korean Academy of Nursing Administration
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• v.20 no.5
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• pp.558-566
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• 2014

Purpose: This study was done to measure the level of social support, self-esteem, and empowerment and to identify any effect of social support and self-esteem on the empowerment of nurses. Methods: The study design was a descriptive survey using questionnaires which were given to 381 nurses in C province. The collected data were analyzed using descriptive analysis, t-test, ANOVA, Pearson correlation coefficient, and multiple regressions. Results: The mean score for nurses' empowerment was $2.83{\pm}0.66$. Seven individual characteristics, social support(family, meaningful persons, supervisors, and co-workers) and self-esteem accounted for 23.3% of the variance in nurses' empowerment. Prediction elements influencing empowerment of nurses were salary per month, self-esteem, and social support(supervisors). Conclusion: The results indicate that it is necessary to increase nurses' empowerment. Social support by supervisors and self-esteem were confirmed as important factors to increase nurses' empowerment. In addition, raising the monthly average income would increase empowerment of nurses.

• Journal of Advanced Research in Ocean Engineering
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• v.3 no.1
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• pp.1-14
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• 2017

The safety analysis of an earthquake is carried out during the operation of a subsea pipeline and an onshore pipeline. Several cases are proposed for consideration. In the case of a buried pipeline, permanent ground deformation by the earthquake and an increase of internal pressure by the acceleration of the earthquake should be considered. In the case of a subsea pipeline, a bending moment is caused by liquefaction of the backfill material on a trenched seabed, etc., which results in a high bending moment of the buried pipeline. The bending moment causes the collapse of the subsea pipeline or a leak of crude oil or gas, which results in economic loss due to enormous environmental contamination and social economic loss owing to operation functional failure. Thus, in order to prevent economic loss and operation loss, structurally sensitive design with regard to seismic characteristics must be performed in the buried pipeline in advance, and the negative impact on the buried pipeline must be minimized by conducting a thorough analysis on the seabed and backfilling material selection. Moreover, it is proposed to consider the selection of material properties for the buried pipeline. A more economical review is also required for detailed study.