• Communications for Statistical Applications and Methods
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• v.16 no.2
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• pp.389-396
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• 2009

Approximations for the null distribution of a test statistic arising in multivariate analysis to test homogeneity of variances and a mixture of two beta distributions by making use of a product of beta baseline density function and a polynomial adjustment, so called beta-polynomial density approximant, are discussed. Explicit representations of density and distribution approximants of interest in each case can easily be obtained. Beta-polynomial density approximants produce good approximation over the entire range of the test statistic and also accommodate even the bimodal distribution using an artificial example of a mixture of two beta distributions.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.6
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• pp.219-226
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• 2002

Filtration performance of an automotive fuel filter was evaluated based on the theory of Beta ratio. This study also introduced the fuel components' contamination performance test stand incorporating the multi-pass filtration test circuit. The theoretical basis of multi-pass test and test procedure were described in detail. The specification of commercial fuel filter currently available was just the maximum pressure drop across the filter assembly and the holding capacity of contaminants. However, test results revealed that the fuel filter tested could not maintain consistent Beta ratio, that is filtration efficiency, although it had the holding capacity close to the specification. Hence the Beta ratio should be specified in service life. The results also showed that filtration system model should be refined including desorption ratio to estimate the variable Beta ratio in the test.

• Environmental Mutagens and Carcinogens
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• v.17 no.2
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• pp.92-96
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• 1997

The micronucleus test using peripheral blood reticulocytes (RETs) was evaluated in ICR mice treated with N-methyI-N-nitrosourea (MNU) and benzo(a)pyrene [B(a)P] as model clastogens. The frequency of micronucleated reticulocytes (MNRETs) in both positive compounds was similar to other results which were reported previously. On the other hand, an anticlastogenic effect of the natural antioxidant, $\beta$-carotene and one of taroholds, galangin as model anticlastogens were investigated using simultaneous treatment. Mice were treated with a model clastogen alone, or with a model clastogen and a model anficlastogen simultaneously. Both $\beta$-carotene and galangin showed anticlastogenic effects against MNU- or B(a)P-induced micronuclei in mice. However, galangin has stronger activity than $\beta$-carotene. Results from our experiment suggest that the in vivo supravital staining micronucleus test using peripheral blood is useful in the evaluation of clastogenic and anticlastogenic effects.

• Journal of Food Hygiene and Safety
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• v.10 no.1
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• pp.29-32
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• 1995

Inclusion complex of omeprazol with $\beta$-Cyclodextrin and Hydroxypropyl-$\beta$-Cyclodextrin were prepared by coprecipitation and freeze-drying method respectively. Effects of these inclusion complex on RBCs were monitored with a spectrophotometer by the method of Kahan et al. and the mutagenic activity based on the Ames plate incorporation test in the presence and absence of liver microsomal enzyme(S9 fraction) using Salmonella typhimurium TA98 and TA100. The RBCs hemolysis and mutagenic activity of these complex were not detected.

• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1245-1255
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• 2015

In this paper, we investigated the major 8 companies of Korean stock market, and carried out the goodness of fit and independence tests. We found out the distributions of absolute returns are closed to compressed exponential distribution. The parameters are dominant that 1 < ${\beta}$ < 2, followed by ${\beta}=1$(exponential distribution) and ${\beta}=2$(normal distribution). Meanwhile, we assured that most of the absolute returns for major 8 companies have relevance to each other by chi-square independence test.

• Journal of the Korean Statistical Society
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• v.7 no.1
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• pp.17-26
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• 1978

For testing $\beta_i=\beta, i=1,...,k$, in the regression model $Y_{ij} = \alpha_i + \beta_ix_{ij} + e_{ij}, j=1,...,n_i$, a simple and robust test based on Kendall's tau is proposed. Its asymptotic distribution is proved to be chi-square under the null hypthesis and noncentral chi-square under an appropriate sequence of alternatives. For the optimal designs, the asymptotic relative efficiency of the proposed procedure with respect to the least squares procedure is the same as that of the Wilcoxon test with respect to the t-test.

• Journal of Technologic Dentistry
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• v.27 no.1
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• pp.9-17
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• 2005

The use of titanium alloys as biomaterials is increasing due to their superior biocompatibility and enhanced corrosion resistance compared to conventional stainless steels and cobalt-based alloys. Ti-6Al-4V ($\alpha+\beta$type) alloy instead of pure titanium ($\alpha$type) is being widely used as biomaterials has some characteristics such as high fatigue strength, tensile strength and corrosion resistance. But it has been reported recently that the vanadium element expresses cytotoxicity and the aluminium element is related with dementia of Alzheimer type and neurotoxicity. In order to overcome their detrimental effects, $\beta$-phase stabilizer Nb was chosen in the present study. This paper was described the influence of phase changes of Ti-Nb alloys on mechanical properties. Ti-3wt.%Nb($\alpha$type),Ti-20wt.%Nb($\alpha+\beta$type) and Ti-40wt.%Nb($\beta$type) alloys were melted by vacuum arc furnace. The specimens were homogenized at 1050$^{\circ}C$ for 24hr and were then hot rolled to 50% reduction. Each alloys were solution heat treated at $\beta$ zone and $\alpha+\beta$ zone after homogenization and then were aged. The mechanical properties of Ti alloys were analysed by hardness test, tensile test, elongation test and SEM test. The results can be summarized as follows: 1) The higher hardness value of $\alpha+\beta$type alloy was obtained compared to the, $\alpha,\beta$type alloys. 2) The aged treated showed better hardness compared to the solution heat treated, homogenized. 3) In the case of solution and aging treatment at $\beta$region, the $\alpha+\beta$type alloy showed the most highest tensile strength and $\beta$type alloy showed the best elongation.

• Korean Journal of Health Education and Promotion
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• v.31 no.4
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• pp.1-10
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• 2014

Objectives: The effectiveness of Blood ${\beta}$-ketone testing by using self-monitoring strip on diabetic patients. Methods: Clinical effectiveness of blood ${\beta}$-ketone testing was assessed through correlation with reference test that measured blood ${\beta}$-ketone value through gas chromatography or enzyme method, diagnostic accuracy, time taken for the test and time taken for confirmative diagnosis of diabetic ketosis by selecting literatures on researches that conducted this test on ketosis(suspected) patients or diabetic ketosis(suspected) patients. Each of the stages from literature search to application of selection standards and extraction of data were carried out independently by the Subcommittee along with 2 researchers. Results: 7 reports were selected. ${\beta}$-ketone testing displayed high level of correlation in the range of r=0.92~0.99 with test using enzyme method as the reference standard. Regarding the diagnostic accuracy, sensitivity of 0.82, specificity of 0.74. The time taken for the test was 30seconds for the index test, which is shorter than reference standard test. Conclusion: Blood ${\beta}$-ketone testing was assessed to be a safe and effective test to monitor ketosis and assess the level of risk of ketosis by measuring the blood ${\beta}$-ketone on ketosis patients and diabetic ketosis patients since it has high level of correlation with reference test and short period of testing.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.3
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• pp.194-201
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• 2003

This study presents the comparative filtration performance evaluation of automotive fuel filters based on the theory of Beta ratio. For the experiments, the fuel component's test stand incorporating the multi-pass filtration test circuit was developed. A mathematical description of filtration process in general was derived. And the theoretical basis of multi-pass test and the test procedure were described in detail. Experimental results revealed that domestic fuel filter tested could not maintain consistent Beta ratio, that is filtration efficiency, although it had the holding capacity of contaminants close to the specification at maximum pressure drop across the filter assembly. The results of experiments and simulations also showed that filtration system model could be refined including desorption ratio to estimate the variable Beta ratio in service life.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.2
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• pp.179-187
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• 2016

This study was conducted to identify the factors that affect the nursing performance. These factors are general characteristics, mentoring function and organizational citizenship behavior. A survey was conducted on 163 nurses working for general hospitals in South Korea from December 2 - 30, 2015. The data was analyzed using the SPSS WIN 21.0 program to analyze the descriptive statistics, independent T-test, ANOVA, Scheffe test, Pearson's correlation, and multiple regression. The factors affecting the subject's nursing performance were altruism (${\beta}=.46$, p<.001), courtesy (${\beta}=.12$, p=.047), belonging to the sub areas of the organizational citizenship behaviors, role modeling function (${\beta}=.31$, p=.001), career develop functions (${\beta}=-.22$, p=.018), belonging to the sub areas of the mentoring function, and position (${\beta}=.24$, p<.001). The results of this study are expected to provide basic data to improve the nursing performance.