• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.3
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• pp.578-584
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• 2017

$SiO_2$ buffer layer (100 nm) has been deposited on PET substrate by electron beam evaporation. And then, IZTO (In-Zn-Sn-O) thin film has been deposited on $SiO_2$/PET substrate with different RF power of 30 to 60 W, working pressure, 1 to 7 mTorr, by RF magnetron sputtering. Structural, electrical and optical properties of IZTO thin film have been analyzed with various RF powers and working pressures. IZTO thin film deposited on the process condition of 50 W and 3 mTorr exhibited the best characteristics, where figure of merit was $4.53{\times}10^{-3}{\Omega}^{-1}$, resistivity, $4.42{\times}10^{-4}{\Omega}-cm$, sheet resistance, $27.63{\Omega}/sq.$, average transmittance (400-800 nm), 81.24%. As a result of AFM, all the IZTO thin film has no defects such as pinhole and crack, and RMS surface roughness was 1.147 nm. Due to these characteristics, IZTO thin film deposited on $SiO_2$/PET structure was found to be a very compatible material that can be applied to the next generation flexible display device.

• Journal of Mushroom
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• v.13 no.3
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• pp.250-255
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• 2015

In this study spent mushroom substrate has ingredient raising rice bed soil. spent mushroom substrates are organic content is 60.72% were nitrogen - phosphoric acid - potassium is 1.39 - 0.89 - 0.81% of the chemical characteristics determine. Post-harvested mushroom substrates of the stabilization process, the temperature of the 20 days time progress in the pH of the rise and fall of temperature down were germination index also 77, as identified, Spent mushroom substrate bed soil for raising rice Ingredient to take advantage of the 20 days or more stabilization process needed to be investigated. Rice seed germination characteristic is in the common bed soil for raising rice ingredients manufactured control group and the comparison in spent mushroom substrate is 10% or less of a mixed experimental population of the germination rate is 82% was more than average days to germination and germination energy, even a statistical significant difference is or control group than good level was ok. Growth initial also spent mushroom substrate is 10% or less of a mixed experimental population of shoot dry matter (top) and grave less than control group higher as confirmed spent mushroom substrates are bed soil for raising rice ingredients are likely to take advantage of the high, as was the judge.

• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.2
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• pp.80-88
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• 2018

Purpose: Implant surface modification and implant design are the principle targets for achieving successful primary stability. The aim of this study was to measure implant stability quotient (ISQ) values of sandblasted, large-grit, acid-etched (SLA) implants with tapered straight body design during the healing period, and to determine the various factors affecting implant stability. Materials and Methods: To measure implant stability, resonance frequency analysis (RFA) was performed in 26 patients (13 women and 13 men) with 44 SLA implants with tapered straight body design. Implant stability (ISQ values) was evaluated at baseline and healing abutment connection (12 weeks), and the correlations between RFA and insertion torque (IT), bone quality, and jawbone were determined. Results: The mean ISQ value of the implants was $69.4{\pm}10.2$ at the time of implant placement (baseline) and $81.4{\pm}6.9$ at the time of healing abutment connection (P < 0.05). Significant differences were found between RFA and bone quality and between RFA and jawbone (P < 0.05). No significant differences were found between RFA and IT, insertion area, fixture diameter, and implant length (P > 0.05). Conclusion: ISQ values of SLA implants with tapered straight body design were high at baseline and healing abutment connection. It was concluded that SLA implants with tapered straight body design show improved primary and secondary stability, and that immediate or early loading may be applicable.

• Journal of the Korea institute for structural maintenance and inspection
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• v.17 no.3
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• pp.126-135
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• 2013

Recently, mass concrete with high flowability are widely used to improve the quality and constructability in the longer span construction of prestressed concrete bridges, but it may induce nonstructural cracks due to the hydration heat and autogenous shrinkage etc. The stresses in concrete were evaluated by various experiments and numerical analysis. The tensile stress in mass concrete was increased in connection with the accumulation of hydration heat. Moreover, large amount of autogenous shrinkage from powder type admixture could add the tensile stress to mass concrete near anchorage zone. The tensile stresses in anchorage zone by heat and autogenous shrinkage exceeded the tensile strength of early stage of concrete, and small amounts of stress increasement were shown in other parts of PSC girder.

• Journal of the Korean Geosynthetics Society
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• v.11 no.4
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• pp.17-25
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• 2012

In this study, it was carried out reliability analysis and slope stability analysis in a standard cross-sectional embankment on high speed railway. It was confirmed that changing tendency of safety factor with various parameter of each soil materials properties and trends of the probability of failure according to the reliability index. The results have shown that a safety factor were relatively large affected an cohesions and internal friction angle of soil compared to the unit weight of soil. Also, most of the standard cross-sectional embankment in high speed railway was generally evaluated the level of below average (below average) by the reliability analysis according to criterion in US. Army but the 12m height of dry embankment case was shown bad condition as Poor.

• Fire Science and Engineering
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• v.17 no.2
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• pp.35-42
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• 2003

In this study, we tried to evaluate the ignitibility, flammability, heat release rate, and toxicity of five different types of burning artificial leather sofa covers that are widely used in entertainment service industry buildings. As the results of this study, putting the artificial leathers under fire conditions we found out following results auto-ignition temperature was$ 427~437^{\circ}C$, limiting oxygen index was 19~20%; at heat flux of $25 kW\m^2$, ignition time was 10~16s and peak heat release rate was $147~277 kW\m^2$; and at heat flux of$ 35 kW\m^2$, ignition time was 6~9s and peak heat release rate was $176~296 kW\m^2$. The toxic materials discharged from the burning leathers were 5,550~6,290 ppm of CO, 18,500~23,400 ppm of $CO_2$, 110~140 ppm, of HCl, 13~65 ppm of HCN and 145~220 ppm of NOx.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.12
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• pp.1865-1870
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• 2010

We develop an IPMC actuator with self-sensing behavior based on an accurate neural network model (NNM). The supplied voltage and voltage signals measured at two determined points on both sides of the IPMC sheet are used as inputs to the NNM. A CCD laser displacement sensor is installed in the rig for accurate measurement of the IPMC tip displacement that is used as the training output of the proposed NNM. Consequently, the NNM model is used to estimate the IPMC tip displacement; the NNM parameters are optimized by the collected input/output training data. The effectiveness of the model for the IPMC actuator is then verified by modeling results.

• International Journal of Highway Engineering
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• v.6 no.4 s.22
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• pp.1-12
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• 2004

This study evaluated the asphalt binder characteristics for the hot-recycled asphalt mixture in which RAP was added in ambient temperature for surface course as well as for base course. RAPs were collected from four sources and their physical properties were evaluated. Mix designs were performed using 10 and 20% RAP contents for surface courses and 10, 20 and 30% for base courses. A virgin asphalt with the penetration grade of 60-80 was used for mixing recycled mixtures. Physical properties of recycled binders, including penetration, absolute viscosity, GPC, BBR and penetration after TFO were measured. From the results, regression analysis of absolute viscosity versus LMS in GPC showed $R^2$ being over 0.95, showing that GPC results estimate the absolute viscosity with relative accuracy. In BBR test, the resistance of recycled mixtures at low service temperature was inferior to the control, because the low temperature PG of recycled binder was one grade higher than that of the control binder.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.3
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• pp.35-45
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• 1999

The research is to examine urban heat island effects which is resulted from urbanization using thermal infrared band of Landsat TM data and to demonstrate heat island alleviation effects of green spaces through correlation analysis of NDVI(Normalized Difference Vegetation Index) and surface temperature. According to the results, forests which are covered with natural vegetation have a high NDVI digital values, but surface temperature is very low, and urban areas which is composed of artificial paving materials have a low NDVI, surface temperature increases gradually. In summary, the analysis of relationship between NDVI and surface temperature, used in this study, is regarded as one of effective methodologies for proving heat island alleviation effects of vegetation.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.151-161
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• 2003

In this study, an interpretation method is proposed to evaluate the stress conditions, including individual excess pore pressure components ($\Delta{u}_{oct}$/ and $\Delta{u}_{shear}$), of normally consolidated clay elements adjacent to the cone face. It is assumed that the stress path of triaxial compression is representative f3r that of the soil element and the soil is elastic-perfectly plastic material. The proposed method is applied to the results of miniature piezocone tests conducted at Louisiana State University calibration chamber system. Based on the results of interpretation, it was found that the ratio of $\Delta{u}_{oct}$/ $\Delta{u}$and $\Delta{u}_{shear}$/$\Delta{u}$ estimated by the proposed method is affected only by the pore pressure parameter. The proposed method gives consistent and reliable values of $\Delta{u}_{oct}$/ $\Delta{u}$and $\Delta{u}_{shear}$/$\Delta{u}$ compared with early works, whereas those obtained by other solutions are significantly dependent on the accuracy in estimating soil properties such as undrained shear strength and rigidity index.