• Electrical & Electronic Materials
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• v.10 no.5
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• pp.467-472
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• 1997

In this study, we investigated the thickness dependence of thermal bleaching(TB) effect as well as photo-induced scalar phenomena, such as photodrakening(PD) effect and photorefraction(PR) change, in chalcogenide A $s_{40}$ G $e_{10}$S $e_{15}$ $S_{35}$ thin films. We found that when these films were exposed for 15 minutes using blue-pass filtered Hg lamp(~4300$\AA$) after annealing for 30 minutes around the glass transition temperature Tg(20$0^{\circ}C$), the refractive index change ($\Delta$n) was varied up to 0.02~0.46 according to each thickness condition and the optical energy gap ($\Delta$ $E_{op}$ ) was shifted to a longer wavelength of approximately 0.67eV, especially for 1000$\AA$-thickness. Also, the TB PD effects have been understood by the results related to optical absorption characteristics. The TB effect could be estimated as increasing the stabilization of amorphous chalcogenide films since absorption slope of extended regions(U) was not changed by annealing. On the other hand, the PD effect could be understood as due to the enhancement of disorder since U and the slope of Urbachs tail(1/F) around an absorption edge were decreased by exposing.ing.n edge were decreased by exposing.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.1
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• pp.1-7
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• 2014

Background: As the increase of forward head position, we studied the change of thickness of deep cervical flexor (DCF) compared of with sternocleidomastoid (SCM). we measured and analysed the change of thickness of the neck flexor for forward head position and cranio-cervical flexion exercise (CCFE). Methods: Using a cross-sectional design, we conducted the study selecting 35 healthy adults (12 males, 23 females). We measured the craniovertebral angle (CVA), instructed them to perform the CCFE, and measured the DCF and SCM using ultrasonography during the contraction and relaxation period. Results: Intra-reliability of SCM is .96, longus capitis is .92 and longus coli is .97. we compared according to the change of forward head position, Correlation of DCF is .841, and DCF/SCM is .754 by significant positive correlation. At the comparison of CCFE and Resting muscle thickness, SCM and DCF is .00, DCF/SCM is .68. Conclusion: There is a strong positive correlation between the change amount of DCF and DCF/SCM as the increase of CVA.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.843-848
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• 2010

This study focused on the characteristics of change soil water with respect to soil thickness and soil mixture ratio, in order to effectively carry out an afforestation system for a roof with a low level of management and a light weight. Soil hardness tended to increase as sand particle was increase regardless soil thickness and soil porosity had more higher artificial soil than natural soil mixture. In case of soil pH, natural soil mixture had between 6.7 and 7.4, and artificial soil mixture had 6.0~6.8. Organic matter, electrical conductance and exchangeable content were highest in $L_{10}$, which it had the highest leafmold ratio. Soil moisture tension(kPa) in 15cm soil thickness was observed natural soil mixture had a considerable change but artificial soil mixture had a gradual change when non-rainfall kept on. In the experimental $L_{10}$, $S_{10}$, $S_7L_3$ and $S_5L_5$ object, the amount of moisture tended to rapidly decrease. However, in the experimental $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$ objects, which contained pearlite and peat moss, the amount of moisture tended to gradually decrease. As a result, the use of a artificial soil mixture soil seems to be required for the afforestation of a roof for a low level of management.

• Journal of the Korean Society of Radiology
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• v.13 no.5
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• pp.705-711
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• 2019

Currently, the brain CT scan of the latest equipment lacks the study of parameter change and dose change and especially of noise, uniformity analysis and dose change. Therefore, this study attempted to study the phenomenon that occurs at this time by analyzing tube voltage, slice thickness, and pitch change in exposure parameters when using high specification CT. Experimental results show that uniformity is better when using high voltage, thick slice thickness selection, and minimum pitch. As a result of the combination, the most uniformity condition was 140 kVp, 10 mm and pitch 0.5. Noise was found to be improved regardless of pitch by increasing tube voltage and slice thickness. The radiation dose increased linearly with tube voltage and pitch. Therefore, the results of this study will serve as a reference for the use of High specification brain CT.

• Journal of radiological science and technology
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• v.44 no.1
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• pp.39-46
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• 2021

This study confirmed the usefulness of the copper filter according to the mode change by comparing and analyzing the energy change according to the application of the copper filter and the change in effective dose and image quality according to the distance to the subject in the DR(Digital Radiography) system. The average energy increased when the copper filter was applied and the reduction rate by 50% of mAs was increased as the thickness of the copper filter increased according to the application of the 10 kVp rule in AEC mode. The effective dose decreased as the thickness increased when the copper filter was applied in AEC(Automatic Exposure Control) mode and manual mode according to the application of the 10 kVp rule, and the decrease rate decreased with increasing 10 kVp increments. As a result of analyzing the dicom images for AEC mode and manual mode with Image J. the PSNR(Peak Signal to Noise Ratio) values were approximate values of less than 30 dB for each mode and for each copper filter thickness. When the copper filter was applied, the average energy increased, so when the 10 kVp rule was applied, the mAs for each mode could be reduced, and the effective dose could also be reduced. However, as the distance and tube voltage increased, the reduction rate of mAs decreased, and the quality of the image was found to decrease when the copper filter was applied, but there was no difference in quality of the image when the copper filter thickness increased.

• Journal of Ceramic Processing Research
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• v.20 no.5
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• pp.499-504
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• 2019

The effect of coating thickness on the contact fatigue and wear of thermal barrier coatings (TBCs) are investigated in this study. The same bondcoat material thickness (250 ㎛) are used for each sample, which allows the effect of the coating thickness of the topcoat to be investigated. TBCs with different coating thicknesses (200, 400, and 600 ㎛) are prepared by changing processing parameters such as the feeding rate of the feedstock, spraying speed, and spraying distance during APS(air plasma spray) coating. The damage size on the surface are strongly affected by the coating thickness effect. Although the damage size from contact fatigue using a spherical indenter diminish at a TBC of 200 ㎛, a high wear resistance such as a low friction coefficient and little mass change are found at a TBC of 600 ㎛. These results indicate that the coating thickness strongly affects the mechanical behavior in TBCs during gas turbine operation.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.1
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• pp.128-141
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• 1996

The pourpose of this study is to determine the exact size which can be the basic elements of the fashion design with the measurement of middle-aged women's body, and to grasp the peculiar tomato type of the middle-aged women by compacting each measurement and examing the change of body shape. Making 215 house wives about 40 to 55 years old the subject of this research, we measured the body size from June to August, 1994. After analyzing the data through the 43 item.; of the body measurement, grasping the characteristics of the tomato type, we classified three types of physical standard and looked into the element of body structure. The results were as follows; 1. The average Rohrer index of middle-aged women in Tas-gu is about 1.5 and they usually seem to be fat compared with other groups. 2. Age has much influence on the body change of middle-aged women. Especially around 45 years old, the body change showed remarkable. 3. When analyzing the elements of the body measurement, the biggest elements of middle -aged women's body structure are in the items of width, thickness and girth related to the expansion of body line. Therefore in the middle age, the thickness and the girth have more influence on the human body than the height and the length, so the items of thickness and girth is the most important factor in the somato type. 4. In the slim body and standard body, the thirst factor is the items of height and length related to vertical size and the second is the items of width and thickness and girth. In ice fat body the first factor is the items of width, thickness, girth and the second is those of height, length. Unlike other body shapes, the fat body has many factors, which shows that the fat body has much variation in each part in proportion to fatness.

• Restorative Dentistry and Endodontics
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• v.22 no.2
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• pp.622-636
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• 1997

Glass ionomer cements, which had been developed in 1972, were widely used as an agent for cementation, base, pit and fissure sealant, and esthetic filling material with the advantages of excellent biocompatibility, anti-cariogenic fluoride release. Specimens were made to evaluate the color change of Glass ionomer cement with a newly developed improved Fuji II Le. Specimens for color change study with cement thickness of 1, 2, 3mm were made and those for the study of color shift pattern were made with the assumption that new mid-shade can be made by mixing of equal amount of both shades in 2mm thickness. After 24 hours in a $37^{\circ}C$ incubator, CIELAB color spaces were evaluated with a spectrophotometer. The results were as follows ; 1. All specimens discolored to dark and blue with an increased thickness in all shades (p<0.05). 2. There were significant $a^*$ space (red-green direction) changes in every A, B, C, D shade series except the relationship between 1mm and 2mm thickness groups in B shade series. But the changes were irregular, i.e., each shade series has its own pattern. 3. Each shade series showed its own specific color shift pattern in all $L^*$, $a^*$, $b^*$ spaces. 4. B shade series showed less amont of changes in ${\Delta}{\pm}E$ than those of A and C shade series (p<0.05), but there was no significant difference in ${\Delta}E$ within each shade series.

• The Journal of Korean Academy of Prosthodontics
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• v.45 no.6
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• pp.769-779
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• 2007

Statement of problem. When TiN coating is applied to the abutment screw, occurrence of greater preload and prevention of the screw loosening could be expected due to decrease of frictional resistance. However, the proper thickness of TiN coating on abutment screw has not been yet reported. Purpose. The purpose of this study is to find out the appropriate TiN coating thickness by evaluating the detorque force and the surface change of titanium abutment screw with various TiN coating thickness. Material and methods. 1. Material Thirty five non-coated abutment screws were prepared for TiN coating. TiN coatings were prepared by Arc ion plating method. Depending on the coating deposition time(CDT), experimental groups were divided into 6 groups(CDT 30min, 60min, 90min, 120min, 150min, 180min) and those of 1 group was not coated as a control group. Each group was made up of 5 abutment screws. 2. Methods FE-SEM(Field Emission Scanning Electron Microscoper) and EDX(Energy Dispersive X-ray Spectroscopy) were used to observe the surface of the abutment screw. Electric scales was used to measure the weight of the abutment screw after the repeated closing and opening of 10 trials. Detorque force was measured with digital torque gauge, at each trial. Results. 1. As the coating deposition time increased, the surface became more consistent and smooth. 2. As for the abutment screws that were TiN coated for more than 60 minutes, no surface change was found after the repeated closing and opening. 3. The TiN coated abutment screws showed less weight change than the non-coated abutment screws. 4. The TiN coated abutment screws showed higher mean detorque force than the noncoated abutment screws. 5. The abutment screw coated for 60 minutes showed the highest mean detorque force. Conclusion. The coating layer of proper thickness is demanded to obtain consistent and smooth coating surface, resistance to wear, and increased detorque force of the abutment screw. In conclusion, the coating deposition time of 60 minutes indicated improved mechanical property, when TiN coating was conducted on titanium abutment screw.

• Journal of Korean Physical Therapy Science
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• v.29 no.3
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• pp.48-55
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• 2022

Background: The purpose of this study is to examine the effect of push-up plus exercise on the changes in the thickness of the trapezius trapezius, serratus anterior and pectoralis major muscles involved in shoulder stability in various support surfaces. Design: Randomized controlled trial. Methods: The thickness change of the shoulder stabilizing muscle was measured using an ultrasound device. Corresponding t-test was performed to confirm the change within the group before the experiment and after 5 weeks. And one-way ANOVA was used to confirm the change between groups after 5 weeks. As a post hoc test, the least significant difference test was performed, and the significance level was set to a=0.05. Results: Changes in the thickness of the trapezius muscle within the group were significantly different between UPEG and SPEG after 5 weeks (p<0.05), and there was a significant difference between groups after 5 weeks (p<0.05). Changes in the thickness of the serratus anterior and pectoralis major muscle within the group were significantly different after 5 weeks in PEG, UPEG and SPEG (p<0.05), and the changes between the groups were significantly different in the serratus anterior muscle after 5 weeks (p<0.05). Conclusion: From the results of this study, it was found that the push-up exercise on an unstable support surface was effective for strengthening the trapezius upper and serratus anterior. This study intends to suggest the possibility of application as basic data for a push-up plus exercise program in clinical practice.