• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.11a
• /
• pp.65-65
• /
• 2007

Microstructure and surface roughness of the sensing materials should be improved to use them in advanced sensor applications because the uneven surface roughness degrades the light reflection, pattern resolution, and devices performance. Chemical mechanical polishing (CMP) processing was selected for improving the surface roughness of $CeO_2$ which is one of the well known materials for the oxygen gas sensors. Surface roughness and removal rate of spin coated $CeO_2$ thin films were examined with a change of CMP process parameters such as down force and table speed. The optimized process condition, reflected by the surface roughness with the hillock-free surface as well as the excellent removal rate with the good uniformity, was obtained. The effects of the improved surface roughness on the sensing property of $CeO_2$ thin films were also confirmed. The improved sensitivity of $CeO_2$ thin films for oxygen sensors were obtained after CMP process by the improved surface characteristics. Therefore, we conclude that sensing property of $CeO_2$ thin film is strongly dependent on the surface roughness of $CeO_2$ thin films by using CMP process.

• Journal of the Korean Society of Physical Medicine
• /
• v.10 no.2
• /
• pp.55-61
• /
• 2015

PURPOSE: The purpose of this study was to investigate recruiting order and onset time around shoulder muscle during the push-up according to the body tilting angle. METHODS: Twenty healthy young adult subjects were recruited for this study. They had no neurological and musculoskeletal disease. We used the sEMG for recording onset time of shoulder muscles. Shoulder Muscles were anterior deltoid(AD), posterior deltoid(PD), pectoralis major(PM), upper trapezius(UT). Body tilting angle were measured at 0 degree, 30 degree and 60 degree by using tilting table. Muscles contraction onset time were set by the push-up performed 3 times respectively. Mean of 3 measurements were used. And initiate onset time was decided by the Mean ${\pm}2$ SD in the threshold, more than 25ms. RESULTS: There were significant difference at 0 degree, 30 degree and 60 degree(p<.05). Muscles onset time were same order at 0 degree, 30 degree. UT occurred first of all contraction at 0 degree and 30 degree. And then contracted AD, PD, PM. But, at 60 degree, AD was the first contraction, and PM, UT, PD. CONCLUSION: Muscle recruitment order and onset time according to the body tilting was shown the difference when you do push-up. Therefore, this result, shoulder muscle recruitment pattern of according to the body tilting is different and it has to make effective shoulder exercise program.

• Journal of Korea Multimedia Society
• /
• v.3 no.2
• /
• pp.101-111
• /
• 2000

Resource managing is very difficult because the multimedia data compressed by a VBR shows a bit rate change within high range, Therefore, the VOD server should use the prefetch method in order to improve system utilization, such as prefetching data in the overload period by a meta table that is the reference pattern of MPEG data which is analyzed off line. This prefetch method will not result in a failure to display at overload, however, this method can not keep a minimum loading time and low costs, because the prefetched section is being maximizes. In this paper, we suggest another method that the system utilization can be improved using the fixed prefetched section to keep loading time and costs under a constant range at overload. But this technique will result in a failure to display, due to fixed prefetched section. Rut, in this paper we suggest a drop module that drops only the B frame in the GOP, consistently distributes a lower drop in media quality for the user.

• The Journal of the Korea Contents Association
• /
• v.21 no.7
• /
• pp.119-126
• /
• 2021

Recently OTT video service has grown rapidly and has a negative impact on the growth of pay-TV subscribers. Consequently the substitution of OTT services for pay-TV services will begin. This study explores OTT usage patterns, dividing into three sectors (OTT service use, OTT usage volume, and paid-OTT service use), by considering users' demographice factors, smart device ownership, pay-TV subscription, and bundle service use, by employing the Mediapanel dataset. The results showed that age, income, smartTV usage, market size, cable/satellite subscribers, TV VOD expenses, movie VOD expenses, and mobile bundle use are associated with OTT service use. The results also showed that age, household sizes, tablePC usgage, cable/satellite subscribers, TV VOD expenses, other VOD expenses, and unlimited data plans are associated with OTT usage volume. Lastly the results showed that age, gender, income, tabletPC usage, cable subscribers, other VOD expenses, mobile bundle usage, and unlimited data plans are associated with paid-OTT service use.

• Journal of Digital Convergence
• /
• v.16 no.11
• /
• pp.465-470
• /
• 2018

This study investigated how layouts can be arranged to improve the user experience in response to changes in the size of responsive webs in a multi - device environment. The layout elements of the responsive web are largely divided into a header, a main concept image, a main content, a sub-content, and a footer. As the screen becomes smaller, the use of drawers and the menu of the scrolling menus rather than the vertical menus will help improve the user experience. The main concept image should be consistent and not lose readability through the use of system fonts. The main content and the sub content should be prevented from being long in the vertical scroll, and the card UI, the table list and the grid list could be alternatively presented for this purpose. Another problem with vertical scrolling is that the placement of user-selectable menus, such as more or new content corrections, is helpful in improving the user experience.

• Journal of Ecology and Environment
• /
• v.43 no.3
• /
• pp.320-331
• /
• 2019

Background: Dioecious plant species having both male and female plants have been investigated regarding sex-related characteristics such as sex ratio, sex-differential resource requirements, and spatial segregation of the sexes. Habitat loss and fragmentation are major threats to the survival of plant populations, but dioecious species are particularly more prone to such habitat degradation than non-dioecious species because of their dimorphic sexual system. We examined the sex-related demographics of two Ilex cornuta populations being different regarding land use history. Methods: During 2016-2017, we examined I. cornuta trees with a basal diameter ${\geq}1.5cm$ in the Yongsu-ri population (YS population) and the Gotjawal Provincial Park population (GP population). Plant sex (male, female, or unsexed) was identified. The tree size (basal diameter and height of the main stem), clonal production (the ramet numbers per genet), and vitality for each clone were measured. The associations between population, sex, tree size, clonal production, and vitality were examined using ANOVAs and contingency table analyses. Finally, point pattern analyses using O-ring statistics were conducted to assess spatial patterns. Results: Upon excluding unsexed trees, the YS population with 74 trees was significantly male-biased (0.66), while the GP population with only 26 trees had a 1:1 sex ratio. In both populations, males and females did not differ in tree size. Although the mean number of ramets differed significantly between populations, females tended to produce more ramets than males. The proportion of weak trees was significantly higher in the YS than in the GP population. Neither population showed evidence of spatial segregation of the sexes. Conclusions: The two populations of dioecious I. cornuta are characterized by the small number of trees and relatively high frequencies of non-reproductive trees. Both indicate that these populations are quite susceptible to environmental and genetic stochasticity. On the other hand, the differences between populations in sex ratio, clonal production, and vitality suggest that conservation efforts for I. cornuta need to be population-specific. In order to help recover and enable this vulnerable species to persist, it is necessary to find ways to enhance their sexual reproduction and simultaneously reduce habitat disturbances due to anthropogenic activities.

• Korea Trade Review
• /
• v.41 no.2
• /
• pp.97-121
• /
• 2016

This study evaluates industrial competitiveness of 34 industries in the 41 countries in terms of several trade indices such as value-added RCA(VRCA) and value added intra-industry trade(VIIT). Conclusions are as follows: First, China is still showing week evidence to replace or overtake Korea in terms of VRCA. Second, it is not supportive of the assertion that the gap between Japan and South Korea had widened in the 1995-2011 period. Third, Korea's exports pattern in the manufacturing sector has shifted from the one featured by developing countries(re-exportation of final goods produced using imported intermediate inputs) to that of the developed (exportation of intermediate goods). According to dynamic panel analysis regressing the RCA gap on the IIT gap, intermediate-goods RCA and the market share gap, the estimated coefficient of the gap between value-added IIT and gross IIT is 0.253 and statistically significant at the 2% level. This implies that increases in IIT or intermediate-goods trade to sustain the global competitiveness are the main reasons for the gap between value-added RCA and gross RCA.

• Journal of the Korean Society for Library and Information Science
• /
• v.56 no.4
• /
• pp.73-100
• /
• 2022

In this study, Samryesugwon is compared with King Jeongjo's anthology because it is not clear why King Jeongjo made Samryesugwon from the Three Classics of Li in a same category but in two different text. As results of this study, it is hard to find information of title because there is no table of contents on the Samryesugwon. Also, King Jeongjo considered and respected the Yili and Zhouli as the original Classics of Li, but not the Liji. Last, it turns out that there is the passive fixed pattern in the way of abridgment instead of the unique characteristic of Jeongjo's abridgment which was compiled before. This research has an academic significance because it figure out the reason why King Jeongjo compiled the Samryesugwon and what his perspective on the Three Classics of Li by textual analyzing as abridgment book.

• Journal of the Korean Geotechnical Society
• /
• v.22 no.12
• /
• pp.77-88
• /
• 2006

A series of model tests were performed to investigate the ground deformation during trench excavation for diaphragm walls. An apparatus was manufactured to observe the failure pattern of a slurry-supported trench in sandy ground. Ground deformations including settlement and lateral displacement of the surrounding ground adjacent to the trench were carefully monitored during excavation. Experimental observations indicated that the settlement of the adjacent ground increased with closing to the trench. Especially, the considerable settlement occurred at the distance which was equal to 40% of the excavation depth. And, the higher settlement was obtained when the relative density of ground was looser and the ground water table was higher. Also, the lateral wall face of excavated trench was bulged with lowering the slurry level In stages and then the upper part of trench failed finally. The envelope of ground surface settlement could be represented as a hyperbolic line and the measured settlement was smaller than those predicted by Clough and O'Rourke (1990).

• Journal of the Korean Association of Geographic Information Studies
• /
• v.13 no.2
• /
• pp.41-53
• /
• 2010

Traffic safety assessment is often accomplished by analyzing the number of crashes occurring in some geographic space over certain specific time duration. In this paper, we introduce a procedure that can efficiently analyze spatial and temporal changes in traffic crashes before-and-after implementation of a certain traffic controlling measure. For the analysis, crash frequency data before-and-after closing a major highway around St. Louis in Missouri was collected through Transportation Management System(TMS) database that is maintained by Missouri Department of Transportation (MoDOT). In order to identify any spatial and temporal pattern in crashes, each crash is pinpointed on a map using the dynamic segmentation in GIS. Then, the identified pattern is statistically confirmed using an analysis of variance table. The advantage of this approach is to easily assess spatial and temporal trend of crashes that are not readily attainable otherwise. The results from this study can possibly be applied in enhancing the highway safety assessment procedure. This paper also makes several suggestions for future development of a comprehensive transportation data system in Korea which is similar to MoDOT's TMS database.