• International Journal of Vascular Biomedical Engineering
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• v.1 no.1
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• pp.3-12
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• 2003

Ultrasonic pulsed Doppler velocimetry has become a standard international method of classifying carotid disease. Because the measured angle adjusted velocity increases as the Doppler angle increases, examinations should be performed at a convenient standard Doppler examination angle. An angle of 60 degrees is achievable throughout most examinations. Multiple Doppler viewing angles allow the acquisition of velocity vectors during the cardiac cycle, revealing the complex velocity patterns. Ultrasonic velocimetry (whether Doppler or time domain) is based on changes in the phase of the ultrasound echo. Other examinations can be done based on the echo phase. Slow motions of organs such as the brain can be used to monitor changes in edema. Measurements of tissue strain due to the pulsatile filling of the arterioles. This plethysmographic imaging method can display differences in tissue perfusion because of different tissue types and changes in autonomic activity.

• Journal of Communications and Networks
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• v.7 no.3
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• pp.284-293
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• 2005

A critical issue in applications involving networks of wireless sensors is their ability to synchronize, and mitigate the fading propagation channel effects. Especially when distributed 'slave' sensors (nodes) reach-back to communicate with the 'master' sensor (gateway), low power cooperative schemes are well motivated. Viewing each node as an antenna element in a multi-input multi-output (MIMO) multi-antenna system, we design pilot patterns to estimate the multiple carrier frequency offsets (CFO), and the multiple channels corresponding to each node-gateway link. Our novel pilot scheme consists of non-zero pilot symbols along with zeros, which separate nodes in a time division multiple access (TDMA) fashion, and lead to low complexity schemes because CFO and channel estimators per node are decoupled. The resulting training algorithm is not only suitable for wireless sensor networks, but also for synchronization and channel estimation of single- and multi-carrier MIMO systems. We investigate the performance of our estimators analytically, and with simulations.

• Language and Information
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• v.12 no.2
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• pp.1-20
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• 2008

This paper examines the effects of focus types on case ellipsis in Korean. A number of previous studies have suggested that accusative case markers in Korean and Japanese cannot be dropped when the object they mark is contrastively focused (Masunaga, 1988; Yatabe, 1999; Ko, 2000; Lee, 2002). Using experimental evidence, we argue against the view that case ellipsis in Korean is sensitive to the distinction between contrastive vs. non-contrastive focus. An alternative analysis is proposed which accounts for the phenomenon of variable case marking in terms of the interaction between the contrastive strength and the discourse accessibility of focused object NPs. By viewing patterns of case ellipsis as the result of balancing between these two forces, such an analysis can correctly predict the gradient pattern of case ellipsis shown by the three types of focused objects tested in the experiment (contrastive replacing focus, contrastive selecting focus and non-contrastive, informational focus), while at the same time offering an explanation for why subtypes of focus exert distinct influences on case ellipsis.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2007.10b
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• pp.84-88
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• 2007

When people recognize a landscape, they first need to see it for a definite period time. This study clarified the way green space in a landscape is recognized using eye movement analysis, and evaluated the Pffi9bility for quantifying stress-reducing effects of seeing a landscape. The results of the experiments on eye movement analysis suggest that the way of recognizing green space in a landscape may depend on a ratio of the amount of scenic greenery in a landscape, color and greenery layout. Especially, this study also suggests that the possibility of the greenery layout guiding eye movement could be verified by conducting a study on planting patterns. In addition, the results of the experiments for quantifying stress-reducing substances found that it is likely that a green space in an urban area has stress-reducing effects.

• The Journal of the Korea Contents Association
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• v.20 no.1
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• pp.519-529
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• 2020

The purpose of this study is to establish a model for predicting academic achievement of college students and to reveal the interrelationship and relative influence of each factor. For this, we surveyed the personal factors and learning strategy factors of 1,310 learners at J University, and analyzed the discriminant factors and patterns of the predictors of academic achievement through the decision tree analysis, a data mining method, and examined the relative effects of each factor. Binary logistic regression analysis was performed for viewing. As a result, the most important factor for predicting academic achievement was efficacy, and other factors such as motivation, time management, and depression were predictive of academic achievement. The patterns of factors predicting academic achievement were found to be high in efficacy and time management, and high in motivation for learning even if the efficacy was moderate. Low efficacy and learning motivation, and high depression have been shown to decrease academic achievement. Based on these results, the study suggested the efficacy and motivation to improve academic achievement of college students, strengthening time management education, and managing negative emotions.

• Journal of Broadcast Engineering
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• v.21 no.2
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• pp.210-218
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• 2016

In this study VOD usage patterns(VOD use and paid amount) of IPTV users were investigated reflecting the level of media use characteristics such as TV viewing time, star preference, and genre preference. Also the impact of media using characteristics and the evaluation of guide channel on the intention to use VOD was analyzed. The web survey was conducted against the respondents who have used VOD and guide channel. The results are as follows. Among the media usage characteristics, star preference has the impact on the VOD use, while genre preference has relation to the willingness to pay for VOD. Secondly, the intention to view the guide channel, entertainment of the channel, and the users' genre preference have significant impacts on the intention to use VOD. Therefore, it is necessary to raise the viewing rate of guide channel by providing the customized promotion strategy and diverse events based on the analysis of VOD usage.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.4
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• pp.537-542
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• 2021

Smart TVs provide a variety of services and information compared to existing TVs based on the Internet. In order to provide more personalized services or information, it is necessary to analyze users' viewing patterns and provide customized services or information based on them. The proposed system receives the user's TV viewing pattern, analyzes it, and recommends a TV program or movie as customized information to the user. For this, the system was constructed with a preprocessor and a deep learning model. The preprocessor refines the name of the TV program watched by the user, the date the TV program was watched, and the watched time. Then, the multi-attribute LSTM model trains the refined data and performs prediction.The proposed system is a system that provides customized information to users, and is believed to be a leading technology in digital convergence that combines existing IoT technology and deep learning technology.

• Korean Journal of Remote Sensing
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• v.34 no.1
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• pp.127-139
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• 2018

The GOCI atmospheric correction overland surfaces is essential for the time-series analysis of terrestrial environments with the very high temporal resolution. We develop an operational GOCI atmospheric correction method over land surfaces, which is rather different from the one developed for ocean surface. The GOCI atmospheric correction method basically reduces gases absorption and Rayleigh and aerosol scatterings and to derive surface reflectance from at-sensor radiance. We use the 6S radiative transfer model that requires several input parameters to calculate surface reflectance. In the sensitivity analysis, aerosol optical thickness was the most influential element among other input parameters including atmospheric model, terrain elevation, and aerosol type. To account for the highly variable nature of aerosol within the GOCI target area in northeast Asia, we generate the spatio-temporal aerosol maps using AERONET data for the aerosol correction. For a fast processing, the GOCI atmospheric correction method uses the pre-calculated look up table that directly converts at-sensor radiance to surface reflectance. The atmospheric correction method was validated by comparing with in-situ spectral measurements and MODIS reflectance products. The GOCI surface reflectance showed very similar magnitude and temporal patterns with the in-situ measurements and the MODIS reflectance. The GOCI surface reflectance was slightly higher than the in-situ measurement and MODIS reflectance by 0.01 to 0.06, which might be due to the different viewing angles. Anisotropic effect in the GOCI hourly reflectance needs to be further normalized during the following cloud-free compositing.

• The Korean Journal of Community Living Science
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• v.20 no.1
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• pp.81-89
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• 2009

The purpose of this study was to analyze the patterns and interrelationships for meeting recommendations of physical activity, sedentary behavior, and dietary behavior in elementary school students. A cross-sectional design was used to assess 259 students ages 11 to 13 years. Physical activity (moderate to vigorous physical activity $\geqq$60min/day), sedentary behavior (viewing time for TV, computer, DVD, video, etc<3hr/day), and dietary behavior (servings of fruits and vegetables$\geqq$5times/day) were categorized into two levels: meeting recommendations or not meeting recommendations. Parents' health behaviors and home environmental variables were assessed with self-reported measures. Chi-squared tests and independent t-tests were conducted to compare anthropometric variables and the prevalence of students not meeting the recommendation for the three health behaviors. Comparison between males and females and logistic linear regression were used to determine the interrelationships of three health behaviors. 25.9% of students did not meet the physical activity recommendations. 15.4% did not meet sedentary behavior recommendations, and 41.7% did not meet dietary recommendation. Only 39.8% of students met all three recommendations, but 19.0% did not meet over two recommendations. Patterns that simultaneously did not meet two recommendations were: sedentary and dietary behavior in males (8.1%), and physical activity and dietary behavior in females (10.4%). Students who did not meet dietary recommendations were at greater risk of not meeting physical activity (OR 2.76; 95% CI 1.15 to 6.64), and sedentary behavior (OR 3.07; 95% CI 1.15 to 8.16) compared with students who did meet dietary recommendations. The findings of this study support not an independent behavior approach but a multiple behavior approach taking into account gender and interrelationships among the three behaviors.

• Journal of the Korean Society of Costume
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• v.63 no.4
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• pp.56-69
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• 2013

This study studies the fabrics from excavated 17th century tombs of Mrs. Min from Yeoheung family(1586~1656), Yeo-on Kim(1596~1665) and Won-rip Choi(1618~1690) and attempts to clarify the relationship between the fashion trend in fabrics of those times and the background behind it by viewing and examining the proportion of twill fabrics to the total silk fabrics and the characteristics of its weave and patterns. Looking into fabrics from the above tombs, twill fabrics accounted for 10.4%(13 pieces) 19.3%(16 pieces) and 9.2%(9 pieces) of total silk fabrics in each of the respective tombs. This forms a remarkable contrast with the fact that there was only one piece of twill silk fabrics(0.5%) and not any from the 16th century tombs of Mrs. Yoon from Papyeong family (0.5%) and Soo-ryoon Sim(0%). In particular, the percentage of hwamun-neung(patterned twill fabrics) in each of the tombs is 8.0%(10 pieces), 13.3%(11 pieces), 9.2%(9 pieces), which is much higher than that of non-patterned one. This is common to the twill fabrics from above three 17th century tombs. Patterns of hwamun-neung(patterned twill), simplified small flower patterns or geometrical figures, from the three excavated tombs are mostly arranged sporadically with blank space. It is supposed that these figurative characteristics reflected the aesthetic sense of the gentry at that time which valued simplicity and moderation for their Confucian standard. This phenomenon of increased use and production of twill fabrics in the 17th century resulted from different factors such as wars like Japanese Invasion of Korea(1592~1598), economic difficulty, government regulations against the production of high-class fabrics, development of weaving skill and its fixation, changes of fabric production environments, and changes of aesthetic sense preferring naive and moderate things to showy ones. As for the weaving characteristics of twill fabrics from the three 17th century tombs 3 leaf warp-faced twill was often used for the ground texture and 4 leaf warp-faced one was occasionally used. For pattern texture 6 leaf weft-faced twill was frequently used, 4 leaf weft-faced twill and 3 leaf weft-faced twill were used at times, and floating one was occasionally used as well.