• Advances in concrete construction
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• v.9 no.3
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• pp.289-299
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• 2020

To investigate the long-term behavior of eccentrically loaded RC columns, which are more realistic in practice than concentrically loaded RC columns, long-term eccentric loading tests were conducted for 10 RC columns. Test parameters included concrete compressive strength, reinforcement ratio, bar yield strength, eccentricity ratio, slenderness ratio, and loading pattern. Test results showed that the strain and curvature of the columns increased with time, and concrete forces were gradually transferred to longitudinal bars due to the creep and shrinkage of concrete. The long-term behavior of the columns varied with the test parameters, and long-term effects were more pronounced in the case of using the lower strength concrete, lower strength steel, lower bar ratio, fewer loading-step, higher eccentricity ratio, and higher slenderness ratio. However, in all the columns, no longitudinal bars were yielded under service loads at the final measuring day. Meanwhile, the numerical analysis modeling using the ultimate creep coefficient and ultimate shrinkage strain measured from cylinder tests gave quite good predictions for the behavior of the columns.

• Journal of Sensor Science and Technology
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• v.17 no.4
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• pp.295-302
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• 2008

$TiO_2,\;ZrO_2$, and $SiO_2$ were added in the concentration of 1 - 3 wt.% to improve long-term stability for the $SnO2$ thick film gas sensor. Short-term sensor resistances up to 90 h were measured to investigate the stabilization time of initial resistance in air. Long-term resistance drifts in air and in gas to 5000 ppm methane for the sensors annealed at $750^{\circ}C$ for 1 h and continuously heated at an operating temperature of $400^{\circ}C$ were also measured up to 90 days at an interval of 1 day. The long-term drifts in methane sensitivity for the three metal oxide-doped $SnO2$ sensors are closely related to methane sensitivity level, catalytic activity, and long-term drift in sensor resistance in air. Those stabilities are mainly discussed in terms of oxidation state and catalytic activity.

• Research in Community and Public Health Nursing
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• v.29 no.4
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• pp.530-538
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• 2018

Purpose: This study tried to identify changes in family burden after the introduction of the long-term care insurance and to examine the factors influencing subjective and objective caring burden and depression of family caregivers of elders receiving home-based long-term care. Methods: Data were collected from 203 family caregivers of elders from August 1 to 31, 2015 using questionnaires. They were analyzed in descriptive statistics, t test, ANOVA test, and multiple regression analysis. Results: The mean score of depression was 7.24, which suggested mild depression level. The subjective family burden was 2.71 and the objective burden 3.04. The factors affecting depression included subjective burden (t=5.08, p<.001), objective burden (t=2.80, p=.006), time of elderly care per day (t=-3.61, p< .001), caregiving duration (t=3.33, p=.001), age (t=3.13, p=.002), family relationship (t=2.48, p=.014), and economic status (t=1.99, p=.047). Conclusion: The family burden was most important influencing factor on caregiver's depression. Therefore, services and supports to alleviate caregivers' burden in the home-based care should be added to long-term care.

• Journal of the Korean Solar Energy Society
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• v.39 no.1
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• pp.41-49
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• 2019

In this study, we analyzed the relationship between four elements: long-wave radiation, the direction of the building, BVR (Building View Ratio), and cloud amount. We examined how long-wave radiations surrounding a building influences the perception of heat in the summer. The results are as follows. (1) Long-wave radiation and BVR are highly correlated regardless of geographical direction. (2) Especially, during dawn in a clear day, areas with high BVR observed high levels of long-wave radiation. (3) This correlation suggests that higher BVR in urban areas will result in a greater number of tropical nights.

• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.143-153
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• 2019

In this study, numerical simulations for the prediction of added resistance for KVLCC2 with varying wave steepness are performed using a Computational Fluid Dynamics (CFD) method and a 3-D linear potential method, and then the non-linearities of added resistance and ship motions are investigated in regular short and long waves. Firstly, grid convergence tests in short and long waves are carried out to establish an optimal mesh system for CFD simulations. Secondly, numerical simulations are performed to predict ship added resistance and vertical motion responses in short and long waves and the results are verified using the available experimental data. Finally, the non-linearities of added resistance and ship motions with unsteady wave patterns in the time domain are investigated with the increase in wave steepness in both short and long waves. The present systematic study demonstrates that the numerical results have a reasonable agreement with the experimental data and emphasizes the non-linearity in the prediction of the added resistance and the ship motions with the increasing wave steepness in short and long waves.

• Water Engineering Research
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• v.4 no.3
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• pp.111-126
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• 2003

Meteorological data are often needed to evaluate the long-term effects of proposed hydrologic changes. The evaluation is frequently undertaken using deterministic mathematical models that require daily weather data as input including precipitation amount, maximum and minimum temperature, relative humidity, solar radiation and wind speed. Stochastic generation of the required weather data offers alternative to the use of observed weather records. The precipitation is modeled by a Markov Chain-exponential model. The other variables are generated by multivariate model with means and standard deviations of the variables conditioned on the wet or dry status of the day as determined by the precipitation model. Ultimately, the objective of this paper is to compare Richardson's model and the improved weather generation model in their ability to provide daily weather data for the crop model to study potential impacts of climate change on the irrigation needs and crop yield. However this paper does not refer to the improved weather generation model and the crop model. The new weather generation model improved will be introduced in the Journal of KWRA.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.04a
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• pp.223-228
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• 2000

Although construction company try to get good quality control it's enough to study about developing objective evaluation method and checking quality method. It is important to meaning concrete quality at placing point, immediate quality checking method is limited. The purpose of this study is to develop new method to know early 28-day concrete for getting faithful quality control. The results of this study are as follows :1) With sealed molds, reduced moisture volatilization to more than 50% and enlarged 20% accelerated compressive strength than before one. 2) Accelerated compressive strength of concrete specimen shows higher strength when it was in the air for long time 3)Interrelation with 7-day and 28-day strength were 0.781,0.90, It is higher than before one

• Proceedings of the IEEK Conference
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• 2000.07b
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• pp.1037-1040
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• 2000

We introduce the forecasting method for a next day electric peak load that uses the optimal combination of two types of neural networks. First network uses learning data that are past 10days of the target day. We name the neural network Short Term Neural Network (STNN). Second network uses those of last year. We name the neural network Long Term Neural Network (LTNN). Then we get the forecasting results that are the linear combination of the forecasting results by STNN and the forecasting results by LTNN. We name the method Combination Forecasting Method (CFM). Then we discuss the optimal combination of STNN and LTNN. Using CFM of the optimal combination of STNN and LTNN, we can reduce the forecasting error.

• International Journal of Advanced Culture Technology
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• v.10 no.2
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• pp.92-97
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• 2022

This study studied the seasons in the novel Snowy Read and the archetypal characteristics in natural phenomena. Summer and winter are the main seasons of Snowy Road. The cycle of the day is the time of dawn and early morning, evening, or night. It is summer now, and memory day is winter. In Snowy Road, 'I' is in sharp conflict with my mom during the summer season. This conflict is resolved and resurfaced with the feeling of 'love' as the story of the day is told in the mother's memory. It was a long time of conflict and trials for winter in the memory of me and my mother. As a result of examining the circular symbols in the Snowy Road, each symbol represents the 'I' and 'the mother's feelings'. 'I' and 'Mom's Emotions' collide, but they confirm each other's sincerity and rebuild their feelings of conflict with 'love'. In Snowy Road, the mother and son's 'love' shows that the mother's son is deeply in love, but the son's mother's love is also very deep.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.221-226
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• 2011

The study was carried out to investigate the effect of MA packaging materials on quality and storability of tomato in long distance export condition. We found that the fresh weight loss in perforated film was higher than other breathable films. The fresh weight of tomato (cv 'Madison') packaged with breathable films, such as 5,000 cc, 10,000 cc, $20,000cc/m^2{\cdot}day{\cdot}atm$ oxygen permeable films, reduced less than 0.6%, but perforated film that already being used for packaging horticultural crops showed 1.4% fresh weight loss during $5^{\circ}C$ storage for 20 days and then $20^{\circ}C$ storage for last 5 days with 85% relative humidity. The carbon dioxide and oxygen concentration in tomato packages showed proper level for MA storage in $20,000cc/m^2{\cdot}day{\cdot}atm$ $O_2$ breathable film treatment at $5^{\circ}C$ storage. Although at $20^{\circ}C$ storage, the carbon dioxide concentration increased sharply, the oxygen concentration decreased remarkably, the change of these gases concentration was the lowest in 20,000 cc film treatment. The ethylene concentration was sharply increased at $20^{\circ}C$ from $21^{st}$ day to $25^{th}$ day after $5^{\circ}C$ storage for 20 day, and the concentration was lower in 20,000 cc film treatment among the breathable film treatments. Until 20 days, at $5^{\circ}C$ storage all treatments did not exceed the marketability. However, the last 5 days during at $20^{\circ}C$, the fruit appeared fungal rots and the quality rapidly decreased. The $20,000cc/m^2{\cdot}day{\cdot}atm$ $O_2$ permeability treated tomato performed higher firmness (9.56 N), vitamin C (16.31 mg/100 gFW), and soluble solids ($7^{\circ}Brix$) than other breathable films at final storage day. The results suggest that the $20,000cc/m^2{\cdot}day{\cdot}atm$ $O_2$ permeable film treatment of tomato (cv 'Madison') performed the highest quality and storability of tomato for long distance exporting.