• Journal of the Korea Academia-Industrial cooperation Society
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• v.10 no.6
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• pp.1175-1179
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• 2009

We analyze voltage characteristics of charged particle type display according to particle layers and cell gap between two electrodes and ascertain the aging effects by measuring the response time of particles with and without aging process. The threshold/driving/breakdown voltage is proportional to layers of charged particles and cell gap and the response time at driving voltage is faster than that of threshold and breakdown voltage because of different q/m of color and black particles. The analysis of response time is a method of estimation of optical characteristics, driving voltage and particle lumping and these results are promoted by aging process. We use the laser and photodiode to measure response time and optical properties. It has not been studied and reported to analyze the relationship of response time, threshold/driving/breakdown voltage, lumping phenomena, cell gap, and aging process for charged particle type display.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.10 no.2
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• pp.64-72
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• 1998

Dynamic response analysis is carried out for slender marine structures such as tensioned risers and tethers of tension leg platform, which are subjected to floating vessel motions as well as environmental forces arising from ocean waves. A mumerical analysis procedure is developed by using finite element model of the structural member. Dynamic analses are performed in the time domain for regular waves. Parameter studies are carried out to highlight the effects of surface vessel motions on the lateral dynamics of the structures. Example results of displacements, bending stresses are compared for various in water depth, environmental condition and vessel motion. Some instability conditions of the structures due to time-varying tension by vessel heave motion are discussed through the example analyses. As the results, the interaction between vessel surge and heave motions amplifies the total structural response of a riser. In the case of a tether, the effect of vessel heave motion during heavy storm is seemed to be quite significant to lateral response of the structure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.793-803
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• 2013

This study was performed to determine the usefulness of scanpath similarity analysis as one of new web usability testing. The 5 websites of public institutions were used and 15 students participated. First of all, eye movements were tracked and visual appeal ratings were measured as participants freely viewed each website for 3 seconds. Subsequently in continuously tracking the eye movements we asked the participants to perform 17 missions. Finally, in interview the participants rated on satisfaction, awareness, and mission difficulty. Results of this study showed that scanpath similarity had a significant relationship with both the visual appeal ratings(first impression) and the satisfaction. In other words, higher the visual appeal ratings were related to higher scanpath similarity. This result showed that measurement such as scanpath similarity of eye movements could become an objective index for usability testing instead of subjective evaluation such as the satisfaction. We discussed possibility that the usability testing by using the scanpath similarity with both fixation and duration on eye movements will find more appropriately inference on observers' experiences in websites.

• Journal of Advanced Navigation Technology
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• v.9 no.2
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• pp.185-192
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• 2005

The aim of this paper is to analyze handling qualities of tiltrotor aircraft(TR-S4) in helicopter flight mode including hovering and forward flight. Analysis of handling qualities is composed of aircraft response to control inputs that effect on stability and controllability. In short term response analysis, bandwidth is the critical parameter for small amplitude motions since it relates to the ability of a pilot to crisply start and stop maneuver. The handling qualities of TR-S4 in helicopter mode are analyzed with a SAS and an attitude controller and are satisfied level 1 in almost criteria with simulation of TR-S4 6-DOF nonlinear model.

• The Journal of the Convergence on Culture Technology
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• v.7 no.4
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• pp.147-153
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• 2021

The purpose of this study is to examine the effects of sleep pattern on regular exercise and to examine mediating effect of subjective health status in the relationship between sleep pattern and regular exercise of older people. For the purpose of the study, older people aged over 65 years old who participated in 2020 Social Survey conducted by Statistics Korea were analyzed. Multiple regression analyses were used and significance of mediating effect was examined using Sobel test for 4,567 older people. Results of the analyses showed that sleep pattern had a significant effect on regular exercise of older people. That is, having an appropriate sleep increased the possibility of doing regular exercise, so the direct effect of sleep pattern on regular exercise was found. Sleep pattern had a significant effect on subjective health status, so older people having an appropriate sleep perceive their subjective health status more positively. As for the mediating effect, subjective health status had partial mediating effects in the relationship between sleep pattern and regular exercise of older people. Results of this study show that sleep pattern of older people should be considered in intervention for improving practicing regular exercise.

• Proceedings of the KAIS Fall Conference
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• 2008.11a
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• pp.167-169
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• 2008

본 논문에서는 대전입자형 디스플레이에 인가된 펄스에 따라 운동하는 대전입자(토너)를 광학적인 관측과 전기적인 측면에서 관찰하였으며, 증폭되는 펄스에 따라 변화하는 대전입자의 응답속도를 측정하여 대전입자의 구동특성을 분석하였다.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.4
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• pp.293-299
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• 2015

The purpose of this study was to investigate the use of balanced movement system for the elderly and for exercise system and lower body balance satisfaction survey results balance, which improved. Elderly people were using the exercise machine for 9 weeks to improve the most inconvenient lower body balance. We have examined periodically analyze the satisfaction survey items. Elderly people were responding to the satisfaction survey items separated by the lower body balance and movement system. The system used is individual customized exercise was possible and there is an interesting content. As a result shows that maintaining the balance of the user is improved. Also, exercise is thought to be by reducing the discomfort of the lower body will help the elderly in activities of daily living and quality of life.

• Geotechnical Engineering
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• v.1 no.1
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• pp.13-20
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• 1985

In this paper, earthquake response of the Bangkok area in Thailand was analyzed in terms of the acceleration response spectrum and maximum acceleration of the computed surface motions. The program SHAKE was employed to analyse the ground motion. With increasing the maximum acceleration and predominant period of given base rock motion, the computed maximum ground surface acceleration increases. but converges on a maximum value of about 0.39. The characteristics of earthquake response spectrum in the Bangkok area are also discussed and illustrated.

• The Journal of Engineering Geology
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• v.25 no.2
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• pp.201-213
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• 2015

Site effects resulting in the amplification of earthquake ground motion are strongly influenced not only by the subsurface soil conditions and structure, but also by the surface topography. Yet, over the last several decades, most studies of site-specific seismic responses in Korea have focused primarily on the seismic amplification associated with geologic and soil conditions. For example, the effects of local geology are now well established and have been incorporated into current Korean seismic design codes, whereas topographic effects have not been considered. To help address this shortcoming, two-dimensional (2D) seismic site response analyses, using finite element (FE) ground modeling with three different slope angles, were performed in order to assess the site effects of surface topography. We then compared our results, specifically peak ground acceleration (PGA) and acceleration response spectrum, to those of one-dimensional (1D) FE model analyses conducted alongside our study. Throughout much of the upper slope region, PGAs and spectral accelerations are larger in the 2D analyses than in the 1D analyses as a result of the topographic effect.

• 한국지구물리탐사학회:학술대회논문집
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• 2005.05a
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• pp.87-92
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• 2005

The ground-motion (GM) attenuation relations available in Korea has required the validation process for large earthquakes since most of them were developed based on small earthquake database, The Fukuoka earthquake (M=7.0) that occurred near the Korean Peninsula provides invaluable data to indirectly evaluate the attenuation characteristics of the strong GM in Korea. The GM levels (PGA, SA) obtained from the KIK-net downhole stations near the epicenter (R<100km) are reasonably predicted by the GM attenuation relation developed by KEPRI in 2003 for the Kori NPP site, the result of which validates the use of KEPRI GM attenuation relation for predicting GM induced by future large earthquakes. Also, the comparison between the Osaki spectra and response spectra of KIK-net downhole data reveals that the amplitude levels of Osaki spectra are higher than the spectra from KIK-net stations which are believed to be installed at the seismic basement.