• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.1
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• pp.73-83
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• 2011

The opening status of Saemangeum sluice gate is an important factor to the coastal water qualities near Saemangeum dikes. The sluice gate opening information is important in analysing current velocity and water quality data measured at the Saemanguem observation tower as well as in determining boundary conditions of numerical simulation for coastal environment outside Saemangeum dikes. This study establishes unmanned camera monitoring system on Saemangeum observation tower using mini notebook and digital camera, and extracts information on the opening status from images automatically. Images are analysed using variance difference of images together with edge detection techniques in order to get correct information.

• Journal of Korean Society for Atmospheric Environment
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• v.28 no.6
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• pp.632-643
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• 2012

Analysis of wind resources in Planetary Boundary Layer (PBL) using long term observation of tall tower located near coast line of the Korean Peninsula were carried out. The data observed at Pohang, Gunsan and Jinhae are wind, temperature and relative humidity with 10 minute interval for one year from 1 October 2010. Vertical turbulence intensity and its deviation at Pohang site is smaller than those of other sites, and momentum flux estimated at 6 vertical layers tend to show small difference in Pohang site in comparison with other sites. The change of friction velocity with atmospheric stability in Pohang is also not so great. These analysis indicate the mechanical forcing due to geographical element of upwind side is more predominant than thermal forcing. On the other hand, wind resources at Gunsan and Jinhae are mainly controlled by thermal forcing.

• Communications for Statistical Applications and Methods
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• v.25 no.2
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• pp.235-243
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• 2018

Many studies exist on the influence of one or few observations on estimators in a variety of statistical models under the "large n, small p" setup; however, diagnostic issues in the regression models have been rarely studied in a high dimensional setup. In the high dimensional data, the influence of observations is more serious because the sample size n is significantly less than the number variables p. Here, we investigate the influence of observations on the least absolute shrinkage and selection operator (LASSO) estimates, suggested by Tibshirani (Journal of the Royal Statistical Society, Series B, 73, 273-282, 1996), and the influence of observations on selected variables by the LASSO in the high dimensional setup. We also derived an analytic expression for the influence of the k observation on LASSO estimates in simple linear regression. Numerical studies based on artificial data and real data are done for illustration. Numerical results showed that the influence of observations on the LASSO estimates and the selected variables by the LASSO in the high dimensional setup is more severe than that in the usual "large n, small p" setup.

• The Bulletin of The Korean Astronomical Society
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• v.42 no.2
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• pp.73.1-73.1
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• 2017

Reverberation mapping is one of the best way to investigate structure and kinematics of broad-line regions around central supermassive black holes of active galactic nuclei (AGN). It is usually used to estimate masses of supermassive black holes. So far, reverberation mapping studies have achieved good results for dozens of AGN by spectroscopic monitoring. However, spectroscopic monitoring is time consuming and high cost. Here, we present result of photometric reverberation mapping with medium-band observation. We monitored five nearby AGN which are already studied, have short time-lag, and show bright H-alpha emission lines. Observation has been performed for ~3 months with ~3 days cadence using three medium-band filters installed in LSGT (Lee Sang Gak Telescope). We found 0.01-0.06 magnitude variations by differential photometry. Also time-lags between continuum light-curves and H-alpha emission line light-curves are calculated using Javelin software. The result shows that our study and previous studies are consistent within uncertainty range. From verification of availability in this study, photometric reverberation mapping could be used as a powerful tool to measure central supermassive black holes for large samples and high-redshift AGN in the future.

• Korean Journal of Veterinary Research
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• v.34 no.2
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• pp.349-359
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• 1994

To elucidate pathogenicity to hamster of encephalomyocarditis virus $K_3$ strain that was isolated in Korea from the swine with reproductive failures, adult male syrian hamsters were experimentally infected intraperitoneally with the virus at $10^{7.0}\;TCID_{50}/0.1ml$ and pathological and immunohistochemical studies were performed. The results obtained through the experiment were as follows. 1. Clinical signs such as depression, unkempt hair and bilateral parlysis of hind limbs were observed. 2. At necropsy, mild congestion was observed in the cerebrum, liver, kidney and lung, and atrophy was evident in testis. 3. In microscopic observation, degeneration and necrosis of the nervous cells and perivascular mononuclear cell infiltration were manifested in central nerve system, and various degrees of degeneration and necrosis of parenchymal cells were detected in pancreas, lacrimal gland, liver, kidney and testis. 4. In immunohistochemical observation, strong positive reactions were observed in degenerated parenchymal cell of testis, and weak positive reactions, in hepatocytes.

• Korean Journal of Child Studies
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• v.33 no.3
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• pp.149-175
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• 2012

This study is designed to positively transform a teacher's emotional state whilst teaching their classes and be able to create happier lessons for preschool children. To do this, a teacher needs to reflect upon current problems and take steps to deal with them. The data for this study was collected from participatory observation and in-depth interviews, making use of photos, a reflective teacher's journal and interview records from Mar. 28, 2011 through Oct. 7, 2011. The problems identified were, (1) teacher centered classes, (2) a daily routine filled with large group activities, (3) disruptive students, and (4) repetitiveness. The routes to greater classroom "happiness" are (1) rearranging seats, (2) "story sharing activities" in small groups, (3) making a separate "story sharing activity" area, (4) using small groups instead of large groups, (5) changing the daily routine. The role of the teacher in finding greater "happiness" are (1) meaningful, 'real observation', (2) discovering genuine change from small points, (3) power sharing, and (4) growing and developing with children.

• International Journal of Contents
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• v.18 no.3
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• pp.21-33
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• 2022

Previous research has provided inconsistent findings as to whether socially (in)competent individuals benefit from social networking sites (SNSs) use. Based on the rich-get-richer model, some studies have shown that socially competent individuals expand their existing networks even further via SNSs use. Based on the poor-get-richer model, other studies have shown that those with poor social skills can achieve beneficiary outcomes from SNSs use by overcoming their deficient social resources of offline environments. The present study is devised to add evidence regarding how and why social skills are related to SNSs use. To this end, we tested the relationships between social competence and three types of Facebook communication activities: interaction, self-presentation, and passive observation. Further, drawing on the social cognitive theory, the mediating role of outcome expectancy in the relationship between social competence and Facebook communication activities was examined. Using an online survey in South Korea (N = 708), it was found that individuals with higher social competence were more likely than those with lower social competence to engage in interaction, self-presentation, passive observation on Facebook. Moreover, these relationships were mediated by outcome expectancy that the desired social outcomes could be achieved as a result of Facebook use.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.101-107
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• 2022

In Korea, the military has been conducting counseling forthe preemptive detection of psychologically unstable soldiers to prevent unexpected accidents and to help them adapt to military life. However, several soldiers feel anxious about face-to-face counseling with military officers and they have difficulty expressing themselves. Video See-Through HMD is a state-of-the-art mixed reality device that converts the user's real view into a digital view, which leads users to feel the actual situation as the virtual. To validate its usefulness as a new psychological counseling aid, we investigated 11 army soldiers who are under the counseling program in barracks. During the counseling conversation, participants were asked to wear or take off the Video See-Through HMD repeatedly. All conversations were recorded for behavioral observation. As a result, 80% of the soldiers showed a relatively stable state of mind when wearing the Video See-Through HMD, which leads them to be innocent and frank about their concerns. This method could improve the effectiveness of counseling to prevent unexpected accidents caused by unnoticeable psychological instabilities of the clients.

• Journal of Korea Game Society
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• v.21 no.6
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• pp.125-134
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• 2021

This study examined the themes and methodologies of 89 game studies published in the fields of media studies, youth studies, and psychology. Youth studies and psychology have mainly covered the theme of game addiction and negative effects. Game research in media studies have covered game use and experience, effects, addiction, regulation, game production, game space, discourse, governmental mechanism, game play as labour, etc. Game research in the fields of youth studies and psychology have mainly relied on surveys and experimental design. Game research in media studies included survey, experimental design, in-depth interviews, participatory observation, data crawling, etc.

• Wind and Structures
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• v.12 no.4
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• pp.333-347
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• 2009

Many tower-supported steel stacks have been constructed in Japan, primarily for economic reasons. However the dynamic behavior of these stacks under a strong wind is not well known and the wind load design standard for this type of a stack has not yet been formulated. In light of this situation, we carried out wind response observation of an operating tower-supported steel stack with and without a tuned-mass damper. The observation revealed the performance of the tuned-mass damper installed on the stack in order to control the wind-induced vibration. Based on the observed data, we performed a wind tunnel test of a specimen of the stack. In this paper we report the results of the wind tunnel test and some comparisons with the results of observation. Our findings are as follows: 1) the tuned-mass damper installed on the specimen in the wind tunnel test worked as well as the one on the observed stack, 2) the amplitude of the vortex-induced vibration of the specimen corresponded approximately to that of the observed stack, and 3) correlation between Scruton number and reduced amplitude, y/d, (y is amplitude, d is diameter) was confirmed by both the wind tunnel test and the observed results.