• Journal of the Korean Society of Safety
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• v.23 no.3
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• pp.51-57
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• 2008

NDT(Non-Destructive Testing Evaluation) using electromagnetic(EM) properties can be used for evaluation of physical performance in cement-based materials. In this study, a technique for strength evaluation in cement mortar is proposed through the measured EM properties(conductivity and dielectric constant). For this research, cement mortar specimens with 5 W/C ratios are made for evaluation of compressive strength and they are also utilized for tests of EM properties in the range of $0.2{\sim}20GHz$ frequency considering exposure condition and curing period. The averaged conductivity and dielectric constant in $5{\sim}20GHz$ frequency are reduced to $83{\sim}93%$ and $81{\sim}87%$, respectively with increasing water to cement ratios. Through the linear regression analysis, relationships between EM properties and results from the compressive strength are obtained, which shows higher correlated factor($0.93{\sim}0.94$) in the specimens exposed to room condition. The gradients in dielectric constant for strength results is measured to be higher than those in conductivity by $3.9{\sim}5.1$ times. The results from dielectric constant in room condition shows the most efficient relation for evaluation of strength.

• Journal of Information Technology Applications and Management
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• v.10 no.3
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• pp.121-142
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• 2003

Most of companies related to the area of B2B electronic commerce are making their efforts to innovate their existing business process into new designed process based on the concept of virtual enterprise. Virtual enterprise can take on many forms and definitions. Nevertheless, the rationale for this business model is clear cooperate to compete, the virtual organization advocates collaboration, partnerships, alliance and similar ideas. This studyintends to suggest an empirical clue to test several hypotheses related to the influence of environmental. organizational, and technological factor to the successful implementation of virtual enterprise in automobile industry. This research surveyed 91 corporations in Korean automobile part industry. Among those samples 86 data of corporate general managers turned out to be statistically valid. This study performed the factor analysis, Cronbach-alpha test. Pearson correlation analysis for testing the validity and the reliability of this research. The results of factor analysis and reliability test indicate that thirty issues to be surveyed are to be grouped into nine factors. The result of multiple regression shows that the influencing factors of eight independent variables on a dependent variable are cooperation between partners, information intensity, IT compatibility, IS maturity. The partners in the strategic alliance will have to trust each other in carrying out their designated roles and responsibilities. and supplying the correct information critical for creating value in virtual business environment.

• Human Ecology Research
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• v.55 no.1
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• pp.13-26
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• 2017

This study investigated the latent groups depending on married working women's work-family spillover. The effects of factors that determine mental health subgroups and differences were also analyzed. Mixture modeling was applied to the Korean Longitudinal Survey of Women & Families to achieve the research objectives. The major findings of this study were as follows. First, there were four subgroups that could be defined according to the work-family spillover: mid-level spillover group (mid-positive and mid-negative spillover group), high-level spillover group (high-positive and high-negative spillover group), low-level spillover group (low-positive and low-negative spillover group), and high-negative and low-positive spillover group. Second, the results of mixture regression analysis to test the effect of eco-system variables showed that age, academic background, non-traditional family value, number of children, work hours, wage income, and availability of the maternity leave were significant determinants of the latent groups. The probability of classifying in the high-negative and low-positive spillover group increased when women showed a lower academic background and wage income, higher number of children and older age, and longer work hours than others. Third, the high-level spillover group, and the high-level spillover group showed the lowest stress and the lowest depression; however, the low-level spillover group reported the highest stress and the highest depression. Implications, limitations, and future directions were discussed based on the results.

• Genomics & Informatics
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• v.14 no.4
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• pp.160-165
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• 2016

Over the past decade, the detection of gene-gene interactions has become more and more popular in the field of genome-wide association studies (GWASs). The goal of the GWAS is to identify genetic susceptibility to complex diseases by assaying and analyzing hundreds of thousands of single-nucleotide polymorphisms. However, such tests are computationally demanding and methodologically challenging. Recently, a simple but powerful method, named "BOolean Operation-based Screening and Testing" (BOOST), was proposed for genome-wide gene-gene interaction analyses. BOOST was designed with a Boolean representation of genotype data and is approximately equivalent to the log-linear model. It is extremely fast, and genome-wide gene-gene interaction analyses can be completed within a few hours. However, BOOST can not adjust for covariate effects, and its type-1 error control is not correct. Thus, we considered two-step approaches for gene-gene interaction analyses. First, we selected gene-gene interactions with BOOST and applied logistic regression with covariate adjustments to select gene-gene interactions. We applied the two-step approach to type 2 diabetes (T2D) in the Korea Association Resource (KARE) cohort and identified some promising pairs of single-nucleotide polymorphisms associated with T2D.

• Korean Journal of Organic Agriculture
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• v.23 no.2
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• pp.185-206
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• 2015

This study aims to prepare a solution necessary for boosting the consumption of environment-friendly agricultural products, positively reflecting consumers' opinions that expect supplies of safe agricultural products to secure the domestic farms producing environment-friendly agricultural products and at the same time, to meet consumers' needs. As a result of the hypothesis testing, of the subjective knowledge in Hypothesis 1, product knowledge had an impact on attitude, while purchase knowledge and use knowledge after purchase were not significant. Of the subjective knowledge in Hypothesis 2, purchase knowledge and product knowledge had significant impacts on purchase intention. Brand image in Hypothesis 3 had a significant impact on attitude, while brand image in Hypothesis 4 had a significant impact on purchase intention. As a result of the mediated regression analysis of Hypothesis 5, all of the subjective knowledge, purchase knowledge, product knowledge and use knowledge after purchase had an impact on purchase intention, partially mediated by attitude, and brand image, too, had an impact on purchase intention, partially mediated by attitude.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.1125-1128
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• 2007

In order to improve the acoustic performance of a noise barrier without increasing its height, various type of acoustic devices are suggested but, there is no proper method to estimate the performance in Korea. For this, an outdoor test facility was established in Expressway and Transportation Technology Institute(ETTI) of Korea Expressway Corporation for testing the acoustical performance of noise reducing devices installed on the top of a noise barrier. Noise measurements before and after installation of the noise reducing devices were carried out by using sound pressure level for long distance range from the barrier, from 10m to 40m. For considering the directivity effects of noise reducing devices, multivariate regression analysis was attempted.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.303-310
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• 2007

The vehicle noise is classified into interior and radiated exterior noise. And it influences on consumer‘s vehicle decision and traffic noise environment very much. In case of the vehicle exterior noise, it is related with traffic noise and in case of the interior noise, it is related with driver’s and passenger‘s sensitivity quality. Because these influenced on drivers and traffic environment, so standards are restricted by the laws and regulated for the measurement. But, the existence standards measuring the only sound pressure level are limit to reflect consumer’s sensitive aspects. Therefore in this study, the recent standards and laws were searched about domestic and abroad papers and the testing mode for the sound quality (SQ) evaluation was constructed about the vehicle interior noise. Finally, we aimed at the standard establishment to evaluate the vehicle interior SQ using statistics method.

• Journal of the Korea Furniture Society
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• v.22 no.1
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• pp.18-25
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• 2011

This experiment was carried out to investigate the effects of nail diameter, driving distance from end on the nail check length, and the effects of nail diameter, prehole for nail driving, and nail driving slope on the nail withdrawal resistance, by the static test of universal testing machine. The test specimen were Japanese cedar (Cryptomeria japonica D. Don.) boards grown in southern district of Korea, and the nails for test were 2.02～4.82 mm in diameter. After nail driving, the back face checks of test boards were longer than the surface checks. The optimum nail diameter without checks or loss of nail withdrawal resistance were below 10% of board width and the optimum driving distance from end of boards were ten multiple of nail diameter. The relation between nail diameter (x) and withdrawal resistance (y) was linear and the regression formulae for Japanese cedar board was y = 8.66x + 7.6 ($R^2=0.978$). As both of the prehole diameter and driving slope were increased, the withdrawal resistances were significantly decreased.

• International Journal of Highway Engineering
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• v.14 no.4
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• pp.51-61
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• 2012

PURPOSES : This study deals with the working life of polymer concrete, which is typically used as a repair or overlay material for portland cement concrete pavements. METHODS : In the scope of this study, laboratory testing was conducted on fresh MMA modified UP polymer concrete, which uses an MMA monomer for viscosity adjustment and strength improvement of UP resin. The experimental variables were temperature (-20 to $+20^{\circ}C$) and binder components (MMA, MEKPO, and DMA). RESULTS : The result showed that the optimum binder ratios for polymer concrete production were 12, 11, and 10 wt.% when the MMA contents were 20, 30, and 40 wt.%, respectively. The working life of polymer concrete depending on temperature and binder components could be expressed by a logarithmic functional formula. The coefficient of variation for each binder component was the highest for DMA content while the lowest for MEKPO content. Also, the contents of each binder component for ensuring the working life of 60 minutes were proposed. CONCLUSIONS : Ultimately, the present study derived a linear regression equation estimating 60 minutes working life based on the setting times of each binder component.

• Childhood Kidney Diseases
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• v.20 no.2
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• pp.79-82
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• 2016

Fabry disease is an X-linked lysosomal storage disorder caused by a deficiency of the enzyme ${\alpha}-galactosidase$ A, resulting in the accumulation of glycosphingolipids within the lysosomes of various cell types. It has a wide spectrum of clinical phenotypes, and renal failure is a serious complication. Fabry disease is confirmed either by measurement of ${\alpha}-galactosidase$ A activity or by genetic testing for GLA mutations. Renal biopsy findings on light microscopy, specifically enlarged podocytes with foamy cytoplasm, and osmiophilic inclusion bodies in the cytoplasm in all types of renal cells on electron microscopy, are characteristic of this disease. The predominant differential diagnosis is iatrogenic phospholipidosis in association with certain drugs that can cause cellular injuries indistinguishable from Fabry disease. Here, we report the case of a 10-year-old boy with microscopic hematuria who underwent a renal biopsy that showed morphological findings consistent with Fabry disease, although the patient had neither a GLA mutation nor a history of drug consumption. Six years later, spontaneous regression of this renal pathology was observed in a second renal biopsy examination.