• Korean Journal of Materials Research
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• v.31 no.8
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• pp.450-457
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• 2021

From measured thermal conductivity and modeling by simulation, this study suggests that U-factors are highly related to materials used between steel and polymer. The objective and prospective point of this study are to relate the relationship between the U-factor and the thermal conductivity of the materials used. For the characterization, EDX, SEM, a thermal conductive meter, and computer simulation utility are used to analyze the elemental, surface structural properties, and U-factor with a simulation of the used material between steel and polymer. This study set out to divide the curtain wall system that makes up the envelope into an aluminum frame section and entrance frame section and interpret their thermal performance with U-factors. Based on the U-factor thermal analysis results, the target curtain wall system is divided into fix and vent types. The glass is 24 mm double glazing (6 mm common glass +12 mm Argon +6 mm Low E). The same U-factor of 1.45 W/m²·K is applied. The interpretation results show that the U-factor and total U-value of the aluminum frame section are 1.449 and 2.343 W/m²·K, respectively. Meanwhile, those of the entrance frame section are 1.449 and 2.

• Bulletin of the Korean Mathematical Society
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• v.60 no.6
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• pp.1523-1537
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• 2023

Let R be a commutative ring with identity and S a multiplicative subset of R. First, we introduce and study the u-S-projective dimension and u-S-injective dimension of an R-module, and then explore the u-S-global dimension u-S-gl.dim(R) of a commutative ring R, i.e., the supremum of u-S-projective dimensions of all R-modules. Finally, we investigate u-S-global dimensions of factor rings and polynomial rings.

• Journal of the Korean Society of Safety
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• v.12 no.2
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• pp.17-21
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• 1997

The fatigue crack propagation rate has so far been measured by the effective stress intensity factor range Δ K/sub eff/. But no research has been done to study how much the crack opening ratio influences the expectation of the fatigue crack propagation. Therefore, this paper evaluates of the crack opening ratio on the fatigue crack propagation life by using the method of parameter sensitivity study. Summarizing the result ; ( 1 ) When the crack opening ratio U' is high, the effect of U' gets larger than any other except for the material factor m. But when U' is low, the effect is also diminished. Therefore, the selection of the lowest value possible is desirable in the evaluation of life. (2) When the value of the material factor m is high, the effect of crack opening ratio U' is increased, at the same time the effect of the other parameters also increased wholly. The effect of material factor m itself on life is high, but in case the material factor m is high, that the effect of each parameter on life get higher is unique. In designing, better attention to the material selection should be drawn. (3) In case the stress ratio R gets smaller, the effect of crack opening ratio U' is unchangeable. But the effect of R itself remarkably decreases, and the effect of material factor m somewhat decreases.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.4
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• pp.189-196
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• 2010

U-factor and solar heat gain coefficient(SHGC) usually can be used as the index to evaluate the thermal performance. U-factor is a concept for heat loss by the temperature difference between inside and outside, so it's useful to be applied in heating season. But SHGC that indicates the fraction of heat from incident solar radiation that flows through a window by means of optical transmission, as well as absorption, re-radiation and convection is for cooling season. In other words, U-factor and SHGC of windows by cities have to be reflected to select the window of the energy conservation. The purpose of this research is to analyze the energy use impacts by SHGCs of windows for detached house in Inchon and Ulsan through energy simulation by eQUEST.

• Journal of Life Science
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• v.26 no.10
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• pp.1189-1195
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• 2016

Vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF) are potent angiogenic factors that have been used clinically to induce angiogenesis. To enable migration and invasion, cells must proliferate and secrete proteinases, which degrade the surrounding extracellular matrix. The goal of this study was to investigate the cell proliferation; matrix metalloproteinase-2 (MMP-2), MMP-9, and plasmin secretion; and migration and invasion of glioma-derived U-373-MG cells induced by VEGF and HGF treatment. An additional goal was to test the hypothesis that elevated secretion of MMP-2, MMP-9, and plasmin contributed directly or indirectly to the proliferation, migration, and invasion of U-373-MG cells. Cell proliferation, migration, and invasion and MMP-2, MMP-9, and plasmin secretion were significantly increased in the VEGF and HGF-treated U-373-MG cells. To elucidate the role of the increased secretion of MMP-2, MMP-9, and plasmin in cell proliferation, migration, and invasion of the U-373-MG cells, they were treated with MMPs inhibitor (BB-94) and plasmin inhibitor (α2AP) prior to VEGF or HGF stimulation. The BB-94 and α2AP treatment resulted in a significant reduction in the cell proliferation, migration, and invasion of the U-373-MG cells as compared with the VEGF- and HGF-treated groups. The results indicate that inhibition of MMPs and plasmin reduce the cell proliferation, migration, and invasion of U-373-MG cells.

• Journal of Fashion Business
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• v.6 no.6
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• pp.34-42
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• 2002

Anthropometric studies and multicultural research on body changes are fundamental and important data for domestic apparel industry and for globalization of women's clothing marketing. The objective of this study is to compare the general body measurements and shoulder angles of Korean and U. S. elderly women to supply basic data for the apparel design. The anthropometric data was collected including both direct and indirect measurements of 272 women over the age of 55 in Korean (subject = 123) and the U.S (subject = 149). The statistical methods used for the analysis of measurement data are the factor and cluster analysis respectively. The results of the factor analysis indicated that 5 factors can be extracted in Korean and 4 factors can be extracted in the U. S. from 15 body measurements to explain the variance. The results of cluster analysis by shoulder slope angle and forward displacement of the shoulder of Korean and the U. S. women classified them in three groups, cluster 1, cluster 2 and cluster 3 respectively.

• The Journal of the Korea institute of electronic communication sciences
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• v.10 no.9
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• pp.1049-1058
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• 2015

This paper aims to study the relationship of U-Traffic Service Quality and User Satisfaction. Independence variables is u-traffic service quality, and mediation parameters are publicity, usefulness and economic. Dependent variable is user satisfaction. Using SPSS 18.0, a series of factor analysis, reliability analysis, multiple regression analysis and path analysis have been performed. The conclusion is as follows. First, U-traffic service quality have a positive effect on user satisfaction directly. Second, U-traffic service quality have a positive effect on user satisfaction through mediation parameters of publicity, usefulness and economic. Third, service quality factor of the U-traffic service quality have more effect on user satisfaction than system quality factor. Last, usefulness among mediation parameters have the most positive effect on user satisfaction.

• Communications of the Korean Mathematical Society
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• v.38 no.1
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• pp.97-112
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• 2023

In this paper, we introduce and study the u-S-weak global dimension u-S-w.gl.dim(R) of a commutative ring R for some multiplicative subset S of R. Moreover, the u-S-weak global dimensions of factor rings and polynomial rings are investigated.

• Journal of Information Technology Services
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• v.10 no.1
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• pp.151-165
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• 2011

Recently building up of u-learning oriented teaching and learning system has been expanded rapidly, However domestic junior college's challenging for adapting it might be slower than other educational body's doing, and in that result it might be paid more or be taken longer time to improve their old system effectively. Now, it is very time for them to develop and implement u-learning oriented teaching and learning system quickly. This paper offers and draws the core factors to design ubiquitous teaching and learning model systematically through investigation of worldwide recent technology and R&D, patent, service and standardization tendency related with u-learnig modeling.

• Journal of Digital Convergence
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• v.10 no.6
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• pp.93-98
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• 2012

This study was to analyze the influences of various factors on the u-health service. Data was surveyed from experienced of u-Health service sectors. We measured legal support, IT-infra, user education, the user education, and the u-Health solution, are the critical success factors for the u-Health service. Also we evaluated u-Health services by survey data from the users. We did also the research to evaluate the validity and reliability of these factors. After that the Analytical Hierarchy Process (AHP) was applied to measure the weights among these factors. Factor analysis resulted in 6 major factors (Eigenvalue > 1.0). The AHP analysis showed the list of Critical Success Factors weighted by its significance priorities. The results of this paper could be the valuable references for the policy making process of the u-Health system in Korea.