• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.222-228
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• 2010

The purpose of this study was to compare mineral trioxide aggregate (MTA; Dentsply, Tulsa Dental, Tulsa, OK, USA), which is widely used as root-end filling material, with DiaRoot BioAggregate (DB; Innovative BioCaramix Inc, Vancouver, BC, Canada), newly developed product, by using MG63 osteoblast-like cells. MTA, DB, and Intermediate Restorative Material (IRM; Dentsply Caulk, Milford, DE, USA) were used for root-end filling material while tissue culture plastic was used for control group. Each material was mixed and, the mixtures were left to set for 24 hours. MG63 cells were seeded to each group and then they were cultured for attachment for 4 hours. Following the attachment of cells to the root-end filling material, early cellular response was observed. After another 12 hours'culture, the level of attachment between cells and material was observed and in order to identify the effect of each material to bone formation, transforming growth factor beta1 ($TGF{\beta}1$) and osteocalin (OC) were estimated by using enzyme-linked immunosorbent assay (ELISA), and the amount of alkaline phosphatase (ALP) was also measured. The data were analyzed using one-way ANOVA. As a result, only at OC and the number of cells which were attached to materials, there was no statistical difference between MTA and DB. At other items, there was statistically significant difference in all groups. Although DB has not shown exactly the same cellular response like that of MTA, the number of attached cells shows that biocompatibility of the material and OC indicates bone formation rate. Therefore, if DB is used for root end filling material, it is expected to lead to similar results to MTA.

• Journal of the Korea Society of Computer and Information
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• v.24 no.2
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• pp.209-215
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• 2019

The objective of this study was to identify the determinants of digital divide according to the characteristics of the elderly. In order to achieve this objective, this study selected elderly people (${\geq}65$ years old) who used a senior welfare center in Chungcheongbuk-do. The survey was conducted using a self-filling survey method for 12 days. Total 289 copies of questionnaires were used for the analysis. The results of this study are as follows. First, gender and age among the demographic characteristics were the factors causing the digital divide of the elderly. Second, education level, economic level, Secondly, education level, economic level, health level, and occupation were factors creating the digital divide of the elderly. This study suggested practical and policy implications based on these results.

• Journal of Information Display
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• v.5 no.4
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• pp.7-11
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• 2004

Effects of base vacuum level on the electrical and optical characteristics of the plasma display panel (PDP) were investigated. The relationship between efficiency and base vacuum level before filling discharge gas was analyzed. For the base vacuum level of $1{\times}10^{-4}$ torr, firing voltage of a 2-inch diagonal PDP panel was 232 V at the discharge gas pressure of 400 torr and luminous efficiency was 1.5 lm/W at 180V sustaining pulse. On the other hand for $1{\times}10^{-6}$torr, the firing voltage was reduced to 215 V and luminous efficiency was improved considerably to 2.5 lm/W. We successfully demonstrated the smooth operation of tip-less PDP fabricated using vacuum in-line sealing method.

• English Language & Literature Teaching
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• v.15 no.3
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• pp.249-282
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• 2009

This study reports on the use of the trait and state cognitive/metacognitive strategy use and the difference of the trait/state strategy use according to students' proficiency level. First of all, for checking up the trait strategy use, 119 first-grade male students in a high school completed the questionnaire on strategies which they thought they used during a reading test. Secondly, to find out their state strategy use, students took a fifteen-item reading comprehension test, followed by filling out questionnaires on cognitive and metacognitive strategies used in the test. This study employed quantitative data analysis. The results suggested that (1) the cognitive and metacognitive strategy use in the trait and state conditions are used the most by the high proficiency group and they are correlated respectively; (2) these strategies are used with statistically significant difference according to students' proficiency level, especially to the lower level students. The highly successful group uses the cognitive and metacognitive strategy in the actual test situation more than the lower proficient group; there is no difference in trait and state strategy use.

• 한국정보디스플레이학회:학술대회논문집
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• 2003.07a
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• pp.832-835
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• 2003

By using vacuum in-line driving and photoluminescence measuring method, we have observed the electrical and optical characteristics of the vacuum in-line sealing technology and analyzed the effect of the base vacuum level before filling the plasma gas. In the case of base vacuum level of $1{\times}10^{-3}$torr, the firing voltage of a 2-inch diagonal PDP panel was ranged from 310 to 345V depending on the plasma gas pressure of 200 to 300torr and luminous efficiency was ranged from 0.0227 to 0.0367 lm/W depending on the input voltage level of 330 to 225V. While, in the case of $1{\times}10^{-6}$, the characteristics were significantly improved. As a results, the firing voltage was ranged from 295 to 318V and luminous efficiency was from 0.0278 to 0.0451 lm/W.

• Journal of the Korean Home Economics Association
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• v.41 no.6
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• pp.13-28
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• 2003

The purposes of this study were to identify money altitudes of college students and to examine both socio-economic characteristics and clothing purchase behaviors by different money attitudes. For this study, guestionnaires completed by 2-year and 4-year college students (n=426) were analyzed by factor analysis, cluster analysis, X²- test, and ANOVA. The results of this study were as follows: First, the money attitudes were composed of five factors and they were categorized by three clusters: cluster of considering the money as a tool for future safety, a way of approval and filling up emotions, and inclination toward stinginess and distrust. Second, the factors which were associated with money attitudes were academic level, education level of parents, household income, students' own income, and the economic level of their households. Third, in each type of attitudes, the clothing purchase behavior had four steps of decision making: problem recognition, information search, evaluation of alternatives, and the purchase. There were significant differences in the clothing purchase behavior among the money attitude styles.

• Journal of the Korean Society of Radiology
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• v.10 no.2
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• pp.117-124
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• 2016

The purpose of this study was tried to evaluate the filling sodium states inside the fuel rod of sodium-cooled fast reactor by digital medical X-ray. We used the diagnostic X-ray generators in digital radiography (DR). This study have found the optimal conditions by changing the effective focal spot size of X-ray tube and post-processing of the DR method with a tungsten edge plate in order to ensure excellent sharpness At this time, the sharpness and resolution were evaluated using the MTF (modulation transfer function). As a result, this study obtained a spatial resolution of 3.871 lp/mm (0.1 MTF), 3.290 lp/mm (0.5 MTF) when implemented the contrast strengthen post-processing in small focal spot. In this research, the result is able to evaluate the level of sodium inside the fuel rod by using the diagnostic X-ray generators in medical digital radiographic images.

• Journal of Korean Association for Spatial Structures
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• v.6 no.3 s.21
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• pp.69-76
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• 2006

Concrete Filled Steel Tube (CFT) system is advantageous because it increases the load-carrying capacity without increasing the size of column. However CFT system has many benefits, it is not applied to field generally because of its heavyweight and difficulty of concrete filling method. As a solution to these problems, we proposed concrete filled steel tube column with hollow made by factory-manufactured PC method. The hollow concrete filled steel tube system is expected to obtain the high strength and high capacity of deformation despite it is a lightweight. This study deals with mechanical properties, strength and deformation, of hollow concrete filled steel tube subjected to axial load. 9 specimens were tested to examine mechanical properties closely, and the following results were obtained: All specimens basically showed higher initial rigidity and maximum strength with increased concrete filling rate. And most specimens showed almost linear behavior until around 80% of maximum strength regardless of filling rate, it is estimated that the elastic range is up to a half of the maximum strength which is the yield strength level.

• Tunnel and Underground Space
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• v.15 no.5 s.58
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• pp.359-368
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• 2005

In case the overburden of a tunnel is too low to adopt NATM, cut and cover method generally can be chosen as alternative. However, in tunneling some area with very low or no overburden between two mountains, the cut and cover method requires additional construction of a couple of tunnel portals and the maintenance of portal slopes until backfilling is completed. As a solution for this problem, increasing the tunnel overburden by raising the ground level can be effective. This paper presents the case study for tunneling at C240 site in Taiwan High Speed Railway(THSR) in which soil-cement filling method was used for pre-banking before tunnel excavation. Cement content of filling material was $2\~4\%$ and thickness of filling a round was $130\~250\;mm$. The stability evaluation for the soil-cement slope and concrete lining of low cover tunnel was conducted by numerical analysis.

• Journal of Biomedical Engineering Research
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• v.18 no.1
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• pp.25-36
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• 1997

To regulate cardiac output of the Total Artificial Heart(TAH) physiologically, the hemodynamic information must be toed back to the controller. So far, our group has developed an automatic cardiac output control algorithm using the motor current waveform, It is, however difficult to detect the preload level such as a filling status of ventricular inflow and the variation of atrial pressures within normal physiologic range(0-15 mmHg) by analyzing the motor current which simultaneously reflects the afterload effect. On the other hin4 the interventricular volume pressure(IVP) which is not influenced by arterload but by preload is a good information source for the estimation of preload states. In order to find the relationship between preload and IVP waveform, we set up the artificial heart system on the Donovan type mock circulatory system and measured the IVP waveform, right and left atrial pressures, inflow and outflow waveforms and the signals represented the information of moving actuator's position. We shows the feasibility of estimating the hemodynamic changes of inflow by using IVP waveform. fife found that the negative peak value of IVP waveform is linearly related to atrial pressures. And we also found that we could use the time to reach the negative peak in IVP waveform, the time to open outflow valve, the area enclosed IVP waveform as unfu parameters to estimate blood filling volume of diastole ventricle. The suggested method has advantages of avoiding thrombogenesis, bacterial niche formation and increasing longterm reliability of sensor by avoiding direct contact to blood.