• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.1
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• pp.237-246
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• 2001

This study is to measure the creep coefficient by 3 days, 7 days and 28 days in the age when loading for the quality assessment of $350kgf/cm^2$ in the high-strength concrete. And it is to analyze the behavior of creep coefficient by applying the experimental data though the compressive strength test, the elastic modulus test and the dry shrinkage test to the ACI-209, AASHTO-94 and CEB/FIP-90, the prediction mode, and the basis of concrete structural design. Also it is to analyze the behavior of short-term creep coefficient during 91 days in the age when loading through the experiment by using the regression analysis, the statistical theory. As applying it to the long-term behavior during 365 days and comparing with the creep prediction mode and examining it, the result from the analysis of the quality of the concrete is as follows. As the result of comparison and analysis about the ACI-209, AASHTO-94 and CEB/FIP-90, the prediction mode, and the basis of concrete structural design, the normal Portland cement class 1 shows the approximate value with the prediction of GEE/PIP-90 and the basis of concrete structural design, but in case of the prediction of ACI-209 and AASHTO-94, there would be worry of underestimation in the application.

• Fashion & Textile Research Journal
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• v.3 no.3
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• pp.283-289
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• 2001

Shrink resist finishing of wool fabric was carried out with Monoethanol aminesulphite (MONAMIN BTN) shrink resist agent after chlorination with Dichloro isocyanuric acid (DCCA). The purpose of this study is to investigate the effect of treating conditions, such as concentrations of DCCA and MONAMIN BTN, pH of treating bath, dyeing times, curing times and temperatures, on dyeing property of wool fabrics. K/S values and fastness properties of dyed wool fabrics were measured. The K/S values of dyed fabrics were increased gradually with increasing concentration, and decreased with increasing curing time. The optimum dyeing time and curing temperature were 60 min and $140^{\circ}C$, respectively. Also it seems likely that the shrink resist finishing carried out at 3% (o.w.f.) of MONAMIN BTN and pH 7 of resin treating bath is effective in increasing K/S values. Light fastness of fabric dyed was very poor and the fastness of fabric dyed was not influenced by the treatment conditions.

• Journal of the Korean Ceramic Society
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• v.37 no.4
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• pp.314-319
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• 2000

Microstructueral development and electrical properties in ZnO-Bi2O3-ZnAl2O4 system were investigated with ZnAl2O4 content(0.1~1.0 mol%). The shrinakge of specimens started around $700^{\circ}C$ and finished at 110$0^{\circ}C$, reaching a maximum shrinkage rate at 80$0^{\circ}C$. The shrinkage rate is strongly related to the fromation of a Bi-rich liquid. The increase of the ZnAl2O4 content inhibited the grain growth of ZnO. Most of ZnAl2O4 particles located at the grain boundaries were about 2~3${\mu}{\textrm}{m}$. ZnO grain size changed little up to 110$0^{\circ}C$, but increased markedly above 115$0^{\circ}C$, especially at lower ZnAl2O4 content. Drastic decreasing in breakdown voltage(Vb) with increasing temperature is expected to be dependent on the ZnO grain size and the distribution of the largest grains between the electrode. The nonlinear I-V characteristic was significantly influenced by the ZnAl2O4 content, which exhibited a maximum value at about 15${\mu}{\textrm}{m}$ of ZnO grain size.

• Journal of Welding and Joining
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• v.31 no.6
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• pp.37-43
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• 2013

This study targets to make clear the connection between MS (Martensite start) point and welding shrinkage. We approved that a Martensite-transformed weldment may not yield state under low MS point, but also admitted the limitation of numerical calculation by inherent strain approach or thermal strain approach. Therefore, new thermal strain formulae during cooling stages were made. As a thermal strain is obtained by integrating thermal extension coefficient, a constant of integration should be decided. In our suggested formulae, the origin was based on totally remained austenite, and added strain from volume changes in Martensite transformation was based on totally transformed ferrite. Through the suggested methodology, It is verified that an MS point under a critical temperature can let weld shrinkage relax and the critical value can be obtained. For supporting this process, 15 weld-consumables were made, were tested by fillet type and were measured. As a result, a positive correlation between MS point and level of weld-distortion was obtained, but it was rather weak.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.4
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• pp.167-172
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• 2019

The strength (MPa), hardness (Hv), shrinkage (%) and biological properties of the HAp were measured by using an organic plasticizer which facilitates the molding and heat treatment. Mechanical properties such as compressive strength, bending strength and hardness were increased with increasing amount of plasticizer, but mechanical properties were decreased when plasticizer was added more than 7 %. This is because addition of the plasticizer above the allowable value causes cracking during molding, and such cracks promote the generation of microcracks and pores at the time of sintering, resulting in a decrease in mechanical properties. As a result of the antimicrobial activity test, no bacteria were detected regardless of the addition amount of plasticizer.

• Journal of the Korea Fashion and Costume Design Association
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• v.10 no.2
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• pp.125-138
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• 2008

For physical and hand property evaluation of fabrics, the knitted fabrics from 11 types of machines knitting fancy yarns, boucle (M1), knot (M2), snarl (M3), and slub (M4), tamtam (M5), tubular (M6), fur 1 (M7), bead (M8), fur 2 (M9), fur 3 (M10), and ladder (M11) yarns, were prepared with 7-10 G plain stitch. Washing test and pilling test had also been carried out. For hand properties by objective sensibility evaluation, 17 items of sir mechanical properties using KES-FB (Kawabata Evaluation System) had been measured. Then hand values of knitted fabrics were calculated with a calculation formula, namely KN-402-KT. Finally the total hand values were obtained through KN-301-WINTER. As a result of physical properties and objective evaluation for machines knitting fancy fabrics, most of them shrank in the direction of wale and course after the washing test, in which their shrinkage rate had a maximum of 3.5%. Therefore, the washing test indicated that the shrinkage ratio of knitted fabrics had a minor change. The results of the pilling test are mostly 4-5th grade, and all of the machines knitting fancy fabrics showed good results in the pilling resistance. In hand properties and objective sensibility evaluation, twisted fancy yarns, such as boucle (M1), knot (M2), snarl (M3), and slub (M4), were superior to bonding rigidity (B) and shear rigidity (G). The surface property between course and wale differs in all samples and course direction is tougher than wale direction. FUKURAMI (fullness and softness) of all samples have high values, besides NUMERI (smoothness) of tamtam (M5) and boucle (M1), which were rather good. Most samples except fur 1 (M7) had low KOSHI (stiffness) value. The total hand value (THV) of twisted yarns was low. This study proves that manufacturers, who plan knitting yarn products and knit fashion, can apply these data to develop machines knitting yarns and knits that fit the consumers' demands.

• Design & Manufacturing
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• v.17 no.3
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• pp.8-14
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• 2023

In this study, basic research was conducted on manufacturing technology of thick-walled light guide a component that controls the light source of automobile lamps. As a preliminary study for manufacturing the final injection molded parts, a model for analyzing the influence of micro patterns on light guides is presented. The optical characteristics of the light guide were analyzed according to the change of the curvature radius of the micro-optical pattern, and the injection molding characteristics of the light guide according to the change of injection molding conditions were analytically evaluated. It was confirmed that the luminance uniformity improves as the R value decreases for changes in the micro-pattern R value, but it was confirmed that there are technical limitations in actual injection mold core processing and high-replication injection molding. Injection molding analysis showed that cooling channel design is very important compared to general injection molding due to thick-wall characteristics and thickness variation. It was also confirmed that the cooling channel has a great influence on the cycle time and birefringence result due to residual stress. As a result of analyzing the influence of filling time, holding condition, and cooling on shrinkage, it was found that the cooling water temperature has a significant effect on the shrinkage of ultra-fine light guide parts, and the holding condition also has a significant effect.

• Genomics & Informatics
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• v.14 no.4
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• pp.149-159
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• 2016

With the success of the genome-wide association studies (GWASs), many candidate loci for complex human diseases have been reported in the GWAS catalog. Recently, many disease prediction models based on penalized regression or statistical learning methods were proposed using candidate causal variants from significant single-nucleotide polymorphisms of GWASs. However, there have been only a few systematic studies comparing existing methods. In this study, we first constructed risk prediction models, such as stepwise linear regression (SLR), least absolute shrinkage and selection operator (LASSO), and Elastic-Net (EN), using a GWAS chip and GWAS catalog. We then compared the prediction accuracy by calculating the mean square error (MSE) value on data from the Korea Association Resource (KARE) with body mass index. Our results show that SLR provides a smaller MSE value than the other methods, while the numbers of selected variables in each model were similar.

• Fashion & Textile Research Journal
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• v.4 no.3
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• pp.289-292
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• 2002

'Burn-Out' is a kind of printing process that can create many textural effects, also high added value of the fabrics. In the previous studies, it is examined how to burn out the cellulose part of the velvet and the polyester/cellulosic fiber mixed fabric without damage of the other part and the effects of process conditions. In this study, dyeing properties of the colored burn-out printing were investigated with various conditions onto the polyester/cellulosic fiber mixed fabrics with red disperse dye. As a results, the apparent color depth (K/S) is increased with increasing of concentration of dye. The optimum treatment conditions without any shrinkage or occurrence of yellowness on the polyester ground fabrics are fixation temperature of $140^{\circ}C$ and time of 3 minutes.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2000.10a
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• pp.484-489
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• 2000

This study was performed to examine the characteristic of creep behavior by reinforced clayey soil. So, it was carried out measurement of compressive strain and poisson's ratio by the reinforced soil mixtures. At each specimen was made by added calcium carbonate and 19mm length monofilaments into soil at designated ratio, and it was measured during the age of 30 days right after manufacturing the specimens. Because monofilaments controled increase of friction and dry shrinkage of soil into soil, compressive strain of monfilments reinforced soil with mixing rate of 0.3% is low value. And Because void was formed by compressive, vertical strain and horizontal strain of calcium carbonate reinforced soil with rate of 9% is high value.