• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.10
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• pp.821-827
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• 2001

In this study performed to identify a degradation mechanism in macromolecular insulating material, the contact angel, surface potential decay, surface resistivity, and XPS analysis were compared after exposure of FRP laminate to plasma discharge. In the case of contact angle, the surface of specimen untreated showed weak hydrophobic property of 73。. However, the contact angle was decreased to 20。in the plasma-treated specimen. In the case of chemical changes arising form plasma treatment, carboxl radicals were generated mainly in the surface treated, which was rapidly changed to the hydrophilic one. In the corona potential decay study to determine the electrical changes of the surface, positive charges were rapidly decreased when compared with negative charges, leading to negative property in the surface of specimen not treated. However, in the case of the hydrophilic surface, lots of carboxl radicals acting as positive polarity were generated, resulting in positive surface. Owing to such positive surface, charges of negative polarity applied were rapidly decreased.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.4
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• pp.622-637
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• 1993

The Purposes of this study were to investigate the significant correlation among the length changes of body surface total lines and between the length changes of body surface total lines and those of component body surface segment lines, and to reveal anticipated relation among body surface length changes by the lower limb movement including all movement direction of hip joint, knee joint & ankle joint for the more functional clothing making & designing. 10 Crosswise & 5 lengthwise body surface total lines and 48 crosswise & 39 lengthwise body surface segment lines of 26 female college students aged from 18 to 24 years were measured directly on the body surface and analyzed by ANOYA & Multiple Comparison Test(Tukey), and the length changes of them were calculated as the difference of the mean length at Fl movement from the mean length at each movement and were analyzed by PEARSON CORRELATION. The results were as following : 1. Correlation among the length changes of body surface total lines (1) Correlation among the length changes of body surface total lines significantly changed by the movement ; 1) The more GA5 expanded, the more GA6 & GA7 each expanded, and the more GA18 expanded, the more GA1 & GA3 each expanded. 2) The more GA15 expanded, the less GA14 each contracted. 3) The more GA7 expanded, the larger GA17 contracted. 4) The more GA1 & GA18 expanded, the larger GA16 contracted, and the larger GM contracted, the less GA16 contracted. (2) Only GA7 and GA17(at F4) showed high (over r=0.7) correlation coefficient, But others' correlation coefficients were r=0.4~0.7. (3) Correlation coefficients among & between girth items and length items 1) Correlation coefficients among girth items were shown + ; between GA3 and GA4, GA5, GA8, between GA5 and GA6, GA7, GA9 each, between GA1 and GA6 and between GA4 and GA7. 2) Correlation coefficients among length items were shown + or - ; shown + between GA14 and GA15 and between GA17 and GA16 ; but Shown - Between GAlS and GA16. 3) Correlation coefficients between girth items and length items were mainly shown - : shown-between GA1 and GA16, GA17, between, GA4 and GA16, between GA6, GA7 each and GA17, between GA8 and GA18 ; but shown + between GA1, GA3 each and GA18 and between GA8 and GA14 were shown +. 2. Correlation between the length changes of body surface total lines and those of component body surface segment lines. (1) All correlation coefficients were + except A147 of GA14. (2) Correlation coefficient over r=0.7 was shown ; between GA3 and CB3, A35 each, between GA5 and A054, between GA6 and A63, between GA7 and A72, A74 each, between GA8 and A83, A84 each, between GA15 and A153, between GA16 and Al64, Al65 each, between GA18 and A189 : but was not shown between GA4, GA17 and it's component body surface segment lines each. (3) Characteristics of correlation between the length changes of body surface total lines and those of body surface segment lines ; 1) If significant correlation of body surface total lines were expansion parts, it's component body surface segment lines was also expansion segment and the otherwise were the same. But exception was shown between expansion line GA3 and A031 (at F4), between GA18 and AlS9 (at F6) and between GA14 and A147, so to speak GA3 & lines and GA14 was contraction total line oppositely A147 was expansion. 2) The more GA3, GAlS expanded, the less A031, A189 contracted. 3) The more GA14 contracted, the more A147 expanded. 4) All correlation except the above 2), 3), the more total lines (GA1, GA3, GA5, GA15, GA16, GA18) expanded, the more segment lines (A15, CB1, A31, A34, CB3, A52, A54, A153, A169, A181) expanded, or the larger total lines (GA14, GA16, GA17) contracted, the larger segment lines (A141, A142, A161, A164, A165, A172) contracted.

• Kyungpook Mathematical Journal
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• v.56 no.4
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• pp.1247-1257
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• 2016

In this paper, we discuss the crossing change operation along exchangeable double curves of a surface-knot diagram. We show that under certain condition, a finite sequence of Roseman moves preserves the property of those exchangeable double curves. As an application for this result, we also define a numerical invariant for a set of surface-knots called du-exchangeable set.

• Journal of the Korean Society of Clothing and Textiles
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• v.20 no.3
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• pp.467-480
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• 1996

Interactions between PET POY and solvents were estimated by the changes in microstructure and surface morphology. Changes in microstructure and surface morphology by the solvent treatments were: an increase in crystallite size, a decrease in interplanar spacing, a change in degree of orientation of crystalline region, a change in surface characteristics.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.5
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• pp.561-568
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• 2003

Surface ozone concentrations are highly sensitive to meteorological variability. Therefore, in order to reveal the long-term changes in ozone due to the changes in precursor emissions, we need to remove the effects of meteorological fluctuations on the annual distribution of surface ozone. In this paper, the meteorologically adjusted trends of daily maximum surface ozone concentrations in two major Korean cities (Seoul and Busan) are investigated based on ozone data from 11 (Seoul) and 6 (Busan) sites over the period 1992 ∼ 2000. The original time series consisting of the logarithm of daily maximum ozone concentrations are splitted into long-term, seasonal and short-term component using Kolmogorov-Zurbenko (KZ) filter. Meteorological effects are removed from filtered ozone series using multiple linear regression based on meteorologcial variables. The long-term evolution of ozone forming capability due to changes in precursor emission can be obtained applying the KZ filter to the residuals of the regression. The results indicated that meteorologically adjusted long-term daily maximum ozone concentrations had a significant upward trend (Seoul: ＋ 3.02% yr$^{-1}$ , Busan: ＋ 3.45% yr$^{-1}$ ). These changes of meteorologically adjusted ozone concentrations represent the effects of changing background ozone concentrations as well as the more localized changes in emissions.

• Korean Journal of Remote Sensing
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• v.39 no.1
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• pp.99-110
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• 2023

Land surface temperature (LST) is a critical environmental indicator affected by land cover (LC) changes. Currently, the most convenient and fastest way to retrieve LST is to use remote sensing images due to their continuous monitoring of the Earth's surface. The work intended to investigate land cover change and temperature response inAn-Najaf province. Landsat multispectral imageries acquired inAugust 1989, 2004, and 2021 were employed to estimate land cover change and LST responses. The findings exhibited an increase in water bodies, built-up areas, plantations, and croplands by 7.78%, 7.27%, 6.98%, 3.24%, and 7.78%, respectively, while bare soil decreased by 25.27% for the period (1989-2021). This indicates a transition from barren lands to different land cover types. The contribution index (CI) was employed to depict how changes in land cover categories altered mean region surface temperatures. The highest LSTs recorded were in bare lands (42.2℃, 44.25℃, and 46.9℃), followed by built-up zones (41.6℃, 43.96℃, and 44.89℃), cropland (30.9℃, 32.96℃, and 34.76℃), plantations (35.4℃, 36.97℃, and 38.92℃), and water bodies (27.3℃, 29.35℃, and 29.68℃) respectively, in 1989, 2004, and 2021. Consequently, these changes resulted in significant variances in LST between different LC types.

• Journal of Korea Water Resources Association
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• v.31 no.6
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• pp.795-806
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• 1998

Soil moisture is affected by regional climate, soil characteristics and land surface condition, etc,. Especially, the changes in land surface condition is more than other factors, which is mainly due to rapid urbanization and industrialization. This study is to evaluate how the change of land surface condition impacts on soil moisture field evolution using a simple model of soil moisture dynamics. For the quantification of soil moisture field, the first half of the paper is spared for the statistical characterization based on the first- and second-order statistics of Washita '92 and Monsoon '90 data. The second half is for evaluating the impact of land cover changes through simulation study using a model for soil moisture dynamics. The model parameters, the loss rate and the diffusion coefficient, have been estimated using the observed data statistics, where the changes of surface conditions are considered into the model by applying various parameter sets with different second-order statistics. This study is concentrated on evaluating the impact due to the changes of land surface condition variability. It is because we could easily quantify the impact of the changes of its areal mean based on the linear reservoir concept. As a result of the study, we found; (1)as the variability of land surface condition, increases, the soil moisture field dries up more easily, (2)as the variabilit y of the soil moisture field is the highest at the beginning of rainfall and decreases as time goes on to show the variability of land surface condition, (3)the diffusion effect due to surface runoff or water flow through the top soil layer is limited to a period of surface runoff and its overall impact is small compared to that of the loss rate field.

• Journal of the Ergonomics Society of Korea
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• v.7 no.1
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• pp.21-30
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• 1988

The investigation of the surface areas, volumes and sizes (circumference, length, breadth) changes has been performed on women during menstruation, non-menstruation, pregnancy and post-pregnancy periods. (1) During menstruation and non-menstruation periods: The subjects were 30 healthy women from 19 to 24 years of age. The changes of lower leg areas were measured using the paper replacement method, showing an increase of 0.71% in surface during the menstruation period. The changes of lower 1g volumes were measured by the water replacement method, showing an increase of 1,74% in volume during the menstruation period. The correlation between the surface area changes and the volume changes was of r=0.45. The greatest change among the four parts of the leg was found at the ankle in both experiments. We measured also the foot length(1), the ball of foot girth(2), the foot breadth(3), the instep height (4), the instep girth(5), the ankle girth(6), the calf circumference(7) and we found the greatest changes in(4)=3,92% in(5)=0.79% and in (7) =0.84%. (2) During pregnancy and post-pregnancy periods: The subjects were 3 women, two pregnants(both from the 24th to the 36th week of pregnancy during the experiment) and one post-pregnant(from the second week to the eighth week during the expriment). For the first two subjects, we measured only the last 6 items of the preceding experiments(foot length(1),ball of foot girth(2), (3), (5), (6), (7)), Showing the greatest changes in the instep girth(5) and the calf circumference(7). In the case of the post-pregnant subject, these two items (5) and(7) decreased sharply during the second, third and fourth week and remain approximately the same afterwards.

• International Journal of Highway Engineering
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• v.20 no.2
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• pp.127-135
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• 2018

PURPOSES : This study develops various models that can estimate the pattern of road surface temperature changes using machine learning methods. METHODS : Both a thermal mapping system and weather forecast information were employed in order to collect data for developing the models. In previous studies, the authors defined road surface temperature data as a response, while vehicular ambient temperature, air temperature, and humidity were considered as predictors. In this research, two additional factors-road type and weather forecasts-were considered for the estimation of the road surface temperature change pattern. Finally, a total of six models for estimating the pattern of road surface temperature changes were developed using the MATLAB program, which provides the classification learner as a machine learning tool. RESULTS : Model 5 was considered the most superior owing to its high accuracy. It was seen that the accuracy of the model could increase when weather forecasts (e.g., Sky Status) were applied. A comparison between Models 4 and 5 showed that the influence of humidity on road surface temperature changes is negligible. CONCLUSIONS : Even though Models 4, 5, and 6 demonstrated the same performance in terms of average absolute error (AAE), Model 5 can be considered the optimal one from the point of view of accuracy.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.5
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• pp.407-413
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• 2005

Ion implantation provides a unique way to modify the mechanical, optical and electrical properties of polymer by depositing the energy of ions in the material on the atomic scale. Implantation of ions into the polymers generally leads to a radiation damage, which, in many cases, modifies the properties of the surface and bulk of the material. These modifications result from the changes of the chemical structure caused in their turn by changing the chemical bonding when the incident ions cut the polymer chains, breaks covalent bonds, promotes cross-linking, and liberates certain volatile species. We studied the relation among the linear energy transfer (LET) and changes of surface microstructure and surface resistivity on PPS material using the high current ion implantation technology The surface resistivity of nitrogen implanted PPS decreased to $10^{7}{\Omega}/cm^{2}$ due to the chain scission, cross linking, ${\pi}$ electron creation and mobility increase. In this case, the surface conductivity depend on the 1-dimensional hopping mechanism.