• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.445-448
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• 2003

Polymer concrete using wastes PET recycled resin that is, in general, more excellent mechanical properties than portland cement concrete. A lot of works are carried out about short-term properties of polymer concrete, however, little work has done to define their long-term properties, that is, sustain load such as creep. In this study will show the data that can long-term behavior of polymer concrete by short term creep test of polymer concrete that was affect to the temperature and the time to predict to long-term creep behavior. Then prediction equation was similar tendency that was comparing to short-term creep test and long-term creep test.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1282-1289
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• 2011

The rail passenger demand for the railroad operations required a short-term demand rather than a long-term demand. The rail passenger demand can be classified according to the purpose. First, the rail passenger demand will be use to the restructure of line planning on the current operating line. Second, the rail passenger demand will be use to the line planning on the new line and purchasing the train vehicles. The objective of study is to analyze the travel behavior of rail passenger for modeling of short-term demand forecasting. The scope of research is the passenger of KTX. The travel behavior was analyzed the daily trips, origin/destination trips for KTX passenger using the ANOVA and the clustering analysis. The results of analysis provide the directions of the short-term demand forecasting model.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.907-914
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• 2012

Flexible pipes take advantage of their ability to move, or deflect, under loads without structural damage. Common types of flexible pipes are manufactured from polyethylene (PE), polyvinyl chloride (PVC), steel, glass fiber reinforced thermosetting polymer plastic (GFRP), and aluminum. In this paper, we present the result of an investigation pertaining to the short-term behavior of buried polyethylene pipe. The mechanical properties of the polyethylene pipe produced in the domestic manufacturer are determined and the results are reported in this paper. In addition, vertical ring deflection is measured by the laboratory model test and the finite element analysis (FEA) is also conducted to simulate the short-term behavior of polyethylene pipe buried underground. Based on results from soil-pipe interaction finite element analyses of polyethylene pipe is used to predict the vertical ring deflection and maximum bending strain of polyethylene pipe.

• Human Ecology Research
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• v.54 no.1
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• pp.107-118
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• 2016

This study examined differences in consumers' images of short-term income forest products, preference, willingness to pay prices and purchase behavior according to dietary lifestyle as well as investigated what factors influence the degree of satisfaction when purchasing short-term income forest products and willingness to repurchase. According to dietary lifestyle, the results classified consumers as 'frugal housewife type,' 'convenience-seeking type,' and 'food high-involvement type.' A 'food high-involvement group' is defined as a group that wants high quality products regardless of price. In the 'frugal housewife type,' country of origin and hygiene/safety (considered when purchasing food) had positive influences on the degree of satisfaction. In the 'convenience-seeking type,' country of origin (considered when purchasing food) had a positive influence on the degree of satisfaction while country of origin (checked when purchasing food) had a negative influence on degree of satisfaction. Consumers had a lack of perception for short-term income forest products; subsequently, short-term income forest products had a weakness of low access to consumers. Therefore, farms for short-term income forest products need to divide products into 'high-priced' luxury products and 'low-priced' frugal products according to dietary lifestyle characteristics, improve packaging status to enable consumers to check quality certificates, and clearly indicate country of origin as well as improve distribution processes and increase consumer access to products.

• Journal of Nutrition and Health
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• v.55 no.1
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• pp.188-199
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• 2022

Purpose: This study investigated the relationship between 3 major constructs of the theory of planned behavior (TPB), i.e., attitude, subjective norms and perceived behavioral control (PBC) and past experience of healthy eating and intentions of healthy eating in the short-term and long-term in adults living in Shanghai and parts of Anhui Province, China. Methods: The online study questionnaire for this cross-sectional study was based on previously validated items. A total of 408 Chinese adults (aged 18-64 years) residing in Shanghai and parts of Anhui Province, China were included to examine relationships between 3 major constructs of TPB and past experience of healthy eating, and short-term and long-term intentions of healthy eating. Multiple linear regression model adjusted for age and body mass index (BMI) was employed to test relationships. Results: Only PBC among 3 major constructs of TPB was significantly related to short-term (p < 0.001) and long-term (p = 0.002) intention of healthy eating after adjustment for age and BMI. Past experience of healthy eating was more significantly related to long-term intention (p < 0.001) compared to short-term (p = 0.020) intention of healthy eating. The short-term and long-term intention models explained 70.5% and 48.8% of the variance, respectively. Conclusion: PBC is a potential determinant of both short-term and long-term behavioral intention of healthy eating regardless of past experience of healthy eating in adults residing in Shanghai and parts of Anhui Province, China. Our results indicate that programs promoting healthy eating to Chinese adults incorporate PCB to perform healthy eating under his or her control.

• Structural Engineering and Mechanics
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• v.62 no.6
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• pp.725-737
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• 2017

An analytical method considering axial equilibrium is proposed for the short- and long-term analyses of shear lag effect in reinforced concrete (RC) box girders. The axial equilibrium of box girders is taken into account by using an additional generalized displacement, referred to as the longitudinal displacement of the web. Three independent shear lag functions are introduced to describe different shear lag intensities of the top, bottom, and cantilever plates. The time-dependent material properties of the concrete are simulated by the age-adjusted effective modulus method (AEMM), while the reinforcement is assumed to behave in a linear-elastic fashion. The differential equations are derived based on the longitudinal displacement of the web, the vertical displacement of the cross section, and the shear lag functions of the flanges. The time-dependent expressions of the generalized displacements are then deduced for box girders subjected to uniformly distributed loads. The accuracy of the proposed method is validated against the finite element results regarding the short- and long-term responses of a simply-supported RC box girder. Furthermore, creep analyses considering and neglecting shrinkage are performed to quantify the time effects on the long-term behavior of a continuous RC box girder. The results show that the proposed method can well evaluate both the short- and long-term behavior of box girders, and that concrete shrinkage has a considerable impact on the concrete stresses and internal forces, while concrete creep can remarkably affect the long-term deflections.

• Journal of Korean Biological Nursing Science
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• v.22 no.2
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• pp.111-118
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• 2020

Purpose: The purpose of this study was to understand the impact of long- and short-term energy drinks on anxiety-like, depressionlike, and cognitive behavior in adolescent rats. Methods: Adolescent rats (age six weeks) were randomly classified into a control group (CON), a long-term administration group (LT), and a short-term administration group (ST). The LT group was orally administered 1.5 mL/100 g (body weight) of energy drink twice daily for 14 days, the ST group was orally administered for one day, and the control group applied the same amount of normal saline. Later, an open-field test, a forced swim test, novel object recognition test, and an 8-arm radial maze test was conducted to assess the rats' anxiety, depression, and cognitive function. Results: There were different effects in the long- and short-term groups of energy drink administration. In the LT group, anxiety- and depressive-like behavior increased because of increased movement in the side corner and decrease of immobility time. Also, the time to explore novel objects decreased, and the number of correct responses was reduced, indicating a learning and memory function disorder. However, the ST group was not different from the control group. Conclusion: These results indicate that long-term consumption of energy drinks can increase anxiety-like, depression-like behavior, and this can lead to decrease in learning and memory functions. Thus, nurse and health care providers should understand the impact of energy drink consumption in adolescence to provide appropriate practices and education.

• Nuclear Engineering and Technology
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• v.54 no.10
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• pp.3878-3887
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• 2022

For the future energy-mix policy for carbon neutrality, demand for the capability of load-follow operation has emerged in nuclear power plants in order to accommodate the intermittency of renewable energy. The short-term decay heat analysis is also required to evaluate the decay heat level varied by the power level change during the load-follow operation, which is a very important parameter in terms of short-term decay heat removal during a grace time. In this study, the short-term decay heat level for 10 days after the shutdown was evaluated for both seasonal and daily load-follow cases. Additionally, the nuclide-wise contribution to the accumulated decay heat for 10 days was analyzed for further understanding of the short-term decay heat behavior. The result showed that in the seasonal case, the decay heat level was mainly determined by the power level right before the shutdown and the amount of each nuclide was varied with the power variation due to the long variation interval of 90 days. Whereas, in the daily case, the decay heat level was strongly impacted by the average power level during operation and meaningful mass variations for those nuclides were not observed due to the short variation interval of 0.5 days.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.477-479
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• 2018

This study was carried out to utilize LSTM(Long Short-Term Memory) technique which is one kind of artificial neural network. Among the 27 types of motion data released by the UTD(University of Texas at Dallas), 3-axis acceleration and angular velocity data were applied to the basic LSTM and Deep Residual Bidir-LSTM techniques to classify the behavior.

• Journal of Korean Association for Spatial Structures
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• v.14 no.3
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• pp.93-100
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• 2014

Ethylene Tetrafluoroethylene (ETFE) has been widely used in long-span buildings because of its light weight and high transparency. This paper studies the short and long term creep behaviour of ETFE foil. A series of short-term creep and recovery tests were performed, in which the residual strain was observed. A long-term creep test of the ETFE foil was also performed over 110 days. A viscoelastic-plastic model was then established to describe the short-term creep and recovery behaviour. The model contains a traditional multi-Kelvin part and an added steady-flow component to represent the viscoelastic and viscoplastic behaviour, respectively. The model successfully fit the data for three stresses and six temperatures. Additionally, time-temperature equivalency was adopted to predict the long-term creep behaviour of ETFE foil. Horizontal shifting factors were determined from the process of shifting creep-curves at six temperatures. The long-term creep behaviours at three temperatures were predicted. Finally, the long-term creep test showed that the short-term creep test at identical temperatures insufficiently predicted additional creep behaviour, and the long-term test verified the horizontal shifting factors derived from the time-temperature equivalency.