• Advances in concrete construction
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• v.11 no.2
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• pp.141-149
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• 2021

This study is a basic research for evaluating the buildability of cementitious materials for three-dimensional (3D) printing. In the cement paste step, the thixotropy behavior according to the resting time, which represents the time interval between each layer, was analyzed. In addition, the relationship between the thixotropy behavior and 3D concrete printing buildability was derived by proposing a measurement method that simulates the 3D concrete printing buildup process. The analysis of the tendency of the thixotropy behavior according to the resting time revealed that the area of the hysteresis loop (AHyst) showed a tendency to increase and then converge as the resting time increased, which means hysteresis loop approach critical resting time for sufficient buildability. In the thixotropy behavior analysis that simulates the 3D concrete printing buildup process, the buildup ratio, which is the recovery rate of the shear stress, showed a tendency to increase and then converge as the resting time increased, which are similar results like hysteresis loop. It was concluded that AHyst and the buildup ratio can be used as parameters for determining the resting time, and they have close relationships with 3D concrete printing buildability.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.143-146
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• 2004

With the rapid growth of e-commerce, marketers are able to observe not only purchasing behavior on what and when customers purchased, but also the individual Web usage behavior that affect purchasing. The richness of this information has the potential to provide marketers with an in-depth understanding of customer. Using commonly available Web log data, this paper examines Web usage behaviors at the individual level. By decomposing the buying process into a pattern of visits and purchase conversion at each visit, we can better understand the relationship between Web usage behavior and purchase decision. This allows us to more accurately forecast a shopper's future purchase decision at the site and hence determine the value of individual customers to the siteAccording to our research, not only information seeking behavior but also visiting duration of a customer and participative behavior such as participation in event should be considered as important predicators of purchase decision of customer in a cosmetic internet shopping mall.

• Journal of Information Technology Services
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• v.13 no.2
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• pp.35-53
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• 2014

Company Social Networks (CSN) has emerged as a commonly used marketing channel. One of the most important advantages in CSN is the user's voluntary behavior as a relational performance. We classified level of voluntary behavior, as 'consumption', 'active participation', and 'creative contribution' to comprehend different relational performance of CSN. Moreover, we proposed research model to compare positive attitude and negative attitude. This study aims to investigate 'the process of user's voluntary behavior in CSN' which is causal relationship between benefits of CSN, user's attitude and voluntary behavior. Empirical results with 175 valid questionnaire data revealed that CSN benefit factors played a significant role in trust and distrust. Based on these effects, trust and distrust have different influences as level of voluntary behavior, just as proposed. For practitioners, it is crucial finding that users are more active behavior based on strong trust.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.372-379
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• 2005

The earthquake resistant design concept allows the nonlinear behavior of structures under the design earthquake. Therefore the response spectrum method provided in most codes introduces the response modification factors to consider the nonlinear behavior in the design process. For bridges, the response modification factors are given according to the ductility as well as the redundancy of piers. In this study, among influence factors on the nonlinear seismic behavior, the randomness of artificial accelerograms simulated with different durations, the pier ductility represented by the inelastic behavior characteristic curve and the regularity represented by pier heights are selected. The influence of such factor on the seismic behavior is investigated by comparing response modification factors calculated with the nonlinear time step analysis.

• Fashion & Textile Research Journal
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• v.11 no.1
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• pp.41-47
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• 2009

The purpose of this study was to investigate the main factors of return and consumers' return behavior types and also to find out the characteristics of consumer's purchasing behavior according to consumer's return behavior type. The Questionnaires was administered 315 males and females, who had experience of clothing purchase and return in internet shopping mall. The results were as follows. First, the factors of return were classified into quality of product, delivery, service, consumer's change of mind, and impulse buying. Second, 4 types of consumer's return behavior were categorized into habitual, dissatisfaction in product quality, dissatisfaction in delivery, and impulse buying. Third, Consumer's return behavior types were not significantly related to the frequency of purchase, information search. However there were significant differences in satisfaction of return process, dissatisfaction after return, and negative word of mouth according to the consumer's return behavior types.

• Computers and Concrete
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• v.20 no.4
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• pp.381-389
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• 2017

The various types of structural materials that are available in the construction industry nowadays make it necessary to predict their stress-strain behavior. Geopolymer are alternatives for ordinary Portland cement concrete that are made from pozzolans activation. Due to relatively new material, many mechanical specifications of geopolymer are still not yet discovered. In this study, stress-strain behavior has been provided from experiments for unconfined geopolymers. Modulus of Elasticity and stress-strain behavior are critical requirements at analysis process and knowing complete stress-strain curve facilitates structural behavior assessment at nonlinear analysis for structures that have built with geopolymers. This study intends to investigate stress-strain behavior and modulus of elasticity from experimental data that belongs for geopolymers varying in fineness and mix design and curing method. For the sake of behavior determination, 54 types of geopolymer are used. Similar mix proportions are used for samples productions that have different fineness and curing approach. The results indicated that the compressive strength ranges between 7.7 MPa and 43.9 MPa at the age of 28 days curing.

• 대한예방의학회:학술대회논문집
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• 2004.10a
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• pp.68.2-69
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• 2004

• Korean Journal of Adult Nursing
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• v.14 no.1
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• pp.83-92
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• 2002

Purpose: This study was performed to identify the process of change, decisional balance and self-efficacy corresponding to the stage of exercise behavior using Transtheoretical Model in patients with type 2 diabetes mellitus. Method: The study method was a survey in 100 type 2 DM patients at out-patients clinic of Y medical center from March 19, 2000 to October 30, 2000. Result: The results were as follows: The subjects were divided into five stages of exercise behavior ; 15.0% in pre-contemplation stage, 33.0% in contemplation stage, 17.0% in preparation stage, 16.0% in action stage and 19.0% in maintenance stage. The subjects in pre-contemplation stage used all processes of change in the least. "Dramatic relief(DR)", "Environmental reevaluation(ER)" and "Self reevaluation(SR)" were identified as main processes of change in contemplation stage. "Consciousness raising(CR)", "DR" were used higher than average in preparation stage. Helping relationships(HR)", "CR", "ER", "SR", "Social liberation(SL)", "Counter conditioning (CC)", "Reinforcement management(RM)", "Self iberation(SEL)" and "Stimulus control(SC)" were used higher than average in action stage. The subjects in maintenance stage used all process of change the highest except "DR"and "HR". "Cons" score of decisional balance was the highest in pre-contemplation stage, "Pros" score was the highest in action stage and "Self-efficacy" score was the highest in maintenance stage. Conclusion: This study can provide the basis of staged matching exercise program using TTM for more effective and useful intervention.

• Journal of Applied Reliability
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• v.18 no.1
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• pp.20-32
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• 2018

Purpose: The purpose of this study is to set up an anomaly detection criteria for sensor data coming from a motorcycle. Methods: Five sensor values for accelerator pedal, engine rpm, transmission rpm, gear and speed are obtained every 0.02 second from a motorcycle. Exploratory data analysis is used to find any pattern in the data. Traditional process control methods such as X control chart and time series models are fitted to find any anomaly behavior in the data. Finally unsupervised learning algorithm such as k-means clustering is used to find any anomaly spot in the sensor data. Results: According to exploratory data analysis, the distribution of accelerator pedal sensor values is very much skewed to the left. The motorcycle seemed to have been driven in a city at speed less than 45 kilometers per hour. Traditional process control charts such as X control chart fail due to severe autocorrelation in each sensor data. However, ARIMA model found three abnormal points where they are beyond 2 sigma limits in the control chart. We applied a copula based Markov chain to perform statistical process control for correlated observations. Copula based Markov model found anomaly behavior in the similar places as ARIMA model. In an unsupervised learning algorithm, large sensor values get subdivided into two, three, and four disjoint regions. So extreme sensor values are the ones that need to be tracked down for any sign of anomaly behavior in the sensor values. Conclusion: Exploratory data analysis is useful to find any pattern in the sensor data. Process control chart using ARIMA and Joe's copula based Markov model also give warnings near similar places in the data. Unsupervised learning algorithm shows us that the extreme sensor values are the ones that need to be tracked down for any sign of anomaly behavior.

• Journal of the Korea Convergence Society
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• v.10 no.2
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• pp.49-56
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• 2019

This study was to examine whether an elderly can health-related quality of life(EQ-5D) by the mediating effect of dental health determinants on the association between health practice behavior and EQ-5D. The analysis was conducted on 1,311 of above the age of 65 in elderly by using raw data from the 2015 National Health and Nutrition Survey. The data were analyzed using SPSS for windows version 24.0 and SPSS PROCESS-macro. The health practice behavior and EQ-5D by living arrangement were the highest in the one-generation family(4.62, 0.90) and the lowest the elderly living alone(4.40, 0.86). Also, analysis using the PROCESS macro indicated that the FS-T index has a mediating effect between health practice behavior and EQ-5D(${\beta}=.0011$, BCCI [.003~.0024]). These findings suggest that FS-T index is closely related to EQ-5D and this will be used as basic data for development of health promotion programs for elderly.