• Journal of Korea Water Resources Association
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• v.52 no.4
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• pp.255-264
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• 2019

The trapezoidal ribs had been installed in the retaining wall in order to reduce to flood damage in the impingement of mountain rivers. In this study, experiments in open channel with the trapezoidal ribs on sidewall were conducted to evaluate the effect of flow resistance by the trapezoidal shape. The hydraulic flow characteristics according to the flow rates were surveyed where the wall roughness is k-type that dimensionless spacings, ${\lambda}_{nv}$, are 6, 9, and 12. The flow-resistance factors such as roughness and friction coefficients increased generally with increase of the spacing of ribs. In high flow rate the friction coefficient showed the maximum value when ${\lambda}_{nv}$ is 9. Though the trapezoidal ribs has the relatively smaller flow resistance compared to the square ribs, their form drag accounted for mean 62% of the total flow resistance. It was confirmed that the optimal spacing of trapezoidal ribs to maximize the effect of flow resistance as the wall roughness increases are 9 to 12 times of the height of trapezoidal ribs.

• 한국노년학
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• v.38 no.3
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• pp.521-536
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• 2018

The purpose of this study is examining the effect of aging attitudes of older people on their life satisfaction, and investigating the mediating role of solidarity between parents and children. To achieve this, the survey was conducted with 2,076 Korean elderlies who were sampled with proportional stratified, and performed multi-mediated regression with SPSS macro PROCESS v.2.16. The results are following. First, aging attitude that older people recognized significantly affects to their life satisfaction. Second, aging attitude significantly affects to the five sub-categories of solidarity between parents and children. Especially, as elderly shows more negative attitude on aging, the solidarity also goes higher. Third, among sub-categories of solidarity between parents and children, affectional, identical, and functional solidarities play roles of mediator on the relationship between aging attitude and life satisfaction, and affectional solidarity shows the biggest influence on the relationship. Based on the results, practical and policy intervention were suggested for better life satisfaction of Korean elderly.

• Atmosphere
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• v.28 no.4
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• pp.415-425
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• 2018

The roles of atmospheric heating formation and distribution on the global circulation are of utmost importance, and those are directly related to not only spatial but also temporal characteristics of monsoon system. In this study, before we clarify the characteristics of apparent heat source <$Q_1$> and moisture sink <$Q_2$>, comparisons of three reanalysis datasets (NCEP2, ERA-Interim, and JRA-55) in its global or regional patterns are performed to clearly evaluate differences among datasets. Considering inter-hemispheric difference of global monsoon regions, seasonal means of June-July-August and December-January-February, which is summer (winter) and winter (summer) in the Northern (Southern) Hemisphere are employed respectively. Here we show the characteristics of eight different regional monsoon regions and find contributions of <$Q_2$> to <$Q_1$> for the regional monsoon regions. Each term in apparent heat source and moisture sink is shown to come from the ERA-Interim dataset, since the ERA-Interim could be representative of three datasets. The NCEP2 data has a different characteristic in the ratio of <$Q_2$> and <$Q_1$> because it overestimates <$Q_1$> compared to the other two different datasets. The Australia monsoon has been performing better over time, while some regional monsoons (South America, North America, and North Africa) have been showing increasing data inconsistency. In addition, the three reanalysis datasets are getting different marching with time, in particular since the early 2000s over South America, North America, and North Africa monsoon regions. The recent inconsistency among the three datasets that may be associated with the global warming hiatus remains unexplored.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.1
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• pp.13-24
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• 2019

This paper brings up fallacy of material factors specified for the design of concrete members in the current Korean limit state design code for highway bridges, and proposes new material factors based on a robust optimization scheme to overcome the fallacy. It is shown that the current load factors in the code and the proposed material factors lead to a much higher reliability index than the target index. The load factors are adjusted to yield the target reliability index using the inverse reliability analysis. A reliability-based approach following the basic concept of Eurocode is formulated to determine material factors as well as load factors. The load-material factors obtained by the proposed reliability-based approach yield a lower reliability level than the target index. Drawbacks of the basic concept of Eurocode are discussed. It is pointed out that differences in the uncertainties between materials and members may cause the lower reliability index of concrete member than the target.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.6
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• pp.309-314
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• 2018

The wind load and structural characteristics of a twin building are more complex than those of conventional high-rise buildings. The pressure load due to wind on a twin building was therefore measured via wind tunnel experiments to analyze such characteristics. The wind pressure pattern was then deduced from measured data using proper orthogonal decomposition. Channeling and vortex shedding were observed in the first and second modes, respectively. The along-wind loads on the two buildings featured a positive correlation and the cross-wind loads featured no correlation. Such a correlation affected the wind-induced displacement. The structural member connecting the two buildings had an insignificant effect on the positive correlation, but it notably reduced the wind-induced displacement with a negative correlation.

• The Korean Journal of Food And Nutrition
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• v.32 no.4
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• pp.371-378
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• 2019

This paper investigated the effects of the percentages of yeast and fermentation time as well as the top and bottom temperature of oven on the baking properties of rice bread. The specific volume of the dough decreased as the amount of added yeast and fermentation time increased. When 1.5% yeast was added at 60 min of fermentation time, the shape of the rice bread showed the largest volume, high appearance and a round shape. The top and bottom temperature of the oven on the baking characteristics of rice bread were affected by the baking time. When the top and bottom temperature of the oven at 200 and $140^{\circ}C$, and 200 and $170^{\circ}C$, the baking time was 20 min. When the top and bottom temperature of oven at 140 and $170^{\circ}C$, the baking time was 40 min. When the top and bottom temperature of the oven were 170 and $170^{\circ}C$, the shape of the rice bread indicated the largest volume, high appearance and a round shape. The results of this study revealed that the replacement of rice flour with 1.5% yeast, 60 min of fermentation time, and the top and bottom temperature of oven at $170-170^{\circ}C$ are effective for rice bread.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.32 no.3
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• pp.149-154
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• 2019

The structural system of domestic high-rise apartments can be divided into two parts; the core wall system, which is composed of walls concentrated in the center and the shear wall system, which comprises a great number of walls distributed in the plan. In order to analyze the lateral behavior of each system, buildings with typical domestic high-rise apartment plans were selected and nonlinear static analysis was performed to investigate the their collapse mechanism. From the force-displacement relation derived from nonlinear static analysis, response modification factor was evaluated by calculating the overstrengh and ductility factor, which are important in the seismic response. The ductility of core wall system is small, but as it is governed by wind load, its overstrength is greatly estimated, and its response modification factor is calculated by the overstrengh factor. Due to a large number of walls, shear wall system has a large ductility, making the response modification factor considerably large.

• Geophysics and Geophysical Exploration
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• v.22 no.1
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• pp.29-36
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• 2019

Regional airborne magnetic survey is very cost-effective mapping tool. Magnetic anomaly maps have abundant information, which are an important tool for understanding the geological evolution and mineral exploration. For this reason, the governments of many countries have made significant investment in the acquisition of airborne geophysical data over many decades. KIGAM (Korea Institute of Geoscience and Mineral Resources) began nationwide airborne magnetic mapping programme in 1982, and completed in 2017. The obtained magnetic data was reprocessed and magnetic database was built in 2018. In addition, the magnetic anomaly map of Korea with a scale of 1:1,000,000 was published. In this paper, we introduced a new magnetic anomaly map of Korea through describing the changing survey parameters during data acquisitions and history of data processing.

• Journal of Korean Society of Rural Planning
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• v.27 no.3
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• pp.85-92
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• 2021

As the paradigm of green has been expended as the core of sustainable development in Korea, agro-healing projects increasingly have been a priority at the national policy and investment area. But little is known about the current overview of national research and development(R&D) related to agro-healing. The aim of this study was generally to investigate the research trends of national R&D related to agro-healing over the past five years. Dataset were gathered from provided by National Science & Technology Information Service(NTIS), word cloud techniques were applied. The main results showed that amounts of number and funding related to agro-healing projects have been increasing. In particular, the Rural Development Administration had the highest number of research, and it was found that the Ministry of Trade, Industry and Energy have spended a lot of money on agro-healing. As a results, it is necessary to expand the scope of the field of agro-healing projects, especially at the multisectoral and intersectoral level for improving health, well-being and a sustainable future.

• Journal of Soil and Groundwater Environment
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• v.26 no.5
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• pp.60-76
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• 2021

The concept of resilience seems applicable for sustainable groundwater management. The resilience is broadly defined as the ability of a system to resist changes by external forces (EFs), and has been used for disaster management and climate change adaptation, including the groundwater resilience to climate change in countries where groundwater is a major water resource, whereas not yet in the geological society of South Korea. The resilience is qualitatively assessed using the absorptive, adaptive, and restorative capacity representing the internal robustness, self-organization, and external recovery resources, respectively, while quantitatively using the system impact (SI) and recovery effort (RE). When the groundwater is considered a complicated system where physicochemical, biological, and geological components interact, the groundwater resilience can be defined as the ability of groundwater to maintain the targeted quality and quantity at any EFs. For the quantitative assessment, however, the resilience should be specified to an EF and measurable parameters should be available for SI and RE. This study focused on groundwater resilience to two EFs in urban areas, i.e., pollution due to land use change and groundwater withdrawal for underground structures. The resilience to each EF was assessed using qualitative components, while measurements for SI and RE were discussed.