• Communications for Statistical Applications and Methods
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• v.16 no.5
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• pp.821-840
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• 2009

This article addresses the problem of estimating a family of general population parameter ${\theta}_{({\alpha},{\beta})}$ using auxiliary information in the presence of measurement errors. The general results are then applied to estimate the coefficient of variation $C_Y$ of the study variable Y using the knowledge of the error variance ${\sigma}^2{_U}$ associated with the study variable Y, Based on large sample approximation, the optimal conditions are obtained and the situations are identified under which the proposed class of estimators would be better than conventional estimator. Application of the main result to bivariate normal population is illustrated.

• Journal of the Korean Data and Information Science Society
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• v.3 no.1
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• pp.47-63
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• 1992

Bechhofer and Tamhane(1981) proposed Balanced Treatment Incomplete Block (BTIB) desings for comparing p test treatments with a control treatment in blocks of size ${\kappa}$. Notz and Tamhane(1983) solved the problem about determination of the minimal complete class for ${\kappa}=3$. However there are a number of design parameters for which BTIB designs do not exist. We suggest a new class of designs called Group Divisible Treatment Desings(GDTD's) that is a larger class including BTIB designs as a subclass. In this paper we give the minimal complete classes of generator designs for GDTD's with ${\kappa}=2,\;p{\geq}4(except\;prime\;number)\;and\;{\kappa}=3,\;p=4(2)6$.

• Journal of Korean Society for Quality Management
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• v.11 no.2
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• pp.18-24
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• 1983

In this paper, subset selection procedures are proposed for selecting the Weibull population with the smallest scale parameter out of k Weibull populations with a common shape parameter. The proposed procedures are based on the maximum likelihood estimators. The constants to implement the procedures are tabulated using Monte Carlo methods. Also, the results of a comparison study are given.

• Research in Mathematical Education
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• v.15 no.2
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• pp.127-140
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• 2011

"Statistical literacy" is important to be an effective citizen ([Gal, I. (2005). Towards "probability literacy" for all citizens: Building blocks and instructional dilemmas. In: G. A. Jones (Ed.), Exploring probability in school: Challenges for teaching and learning (pp. 39-63). New York: Springer]). Probability and statistics has been connected with real context and can be used to stimulate students' creative abilities. This study aims at identifying the extent that textbooks in three countries include experimental probability concepts and non-routine, open-ended, application and contextual problems. How well textbooks reflect real application situations is important in the sense that students can employ probability concepts when solving real world problems. Results showed that three textbook series did not mention experimental probability. Furthermore, all of text-books had more routine, close-ended, knowing, and non-contextual problems.

• Communications for Statistical Applications and Methods
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• v.25 no.3
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• pp.263-274
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• 2018

One of the common issues in large dataset analyses is to detect and construct homogeneous groups of objects in those datasets. This is typically done by some form of clustering technique. In this study, we present a divisive hierarchical clustering method for two monothetic characteristics of histogram data. Unlike classical data points, a histogram has internal variation of itself as well as location information. However, to find the optimal bipartition, existing divisive monothetic clustering methods for histogram data consider only location information as a monothetic characteristic and they cannot distinguish histograms with the same location but different internal variations. Thus, a divisive clustering method considering both location and internal variation of histograms is proposed in this study. The method has an advantage in interpreting clustering outcomes by providing binary questions for each split. The proposed clustering method is verified through a simulation study and applied to a large U.S. house property value dataset.

• International Journal of Reliability and Applications
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• v.4 no.4
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• pp.171-181
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• 2003

This paper proposes a U-test statistic for the problem of testing that a life distribution is exponential against the alternative that it is harmonic new better (worse) than used in expectation upper tail HNBUET (HNWUET), but not exponential on complete data. Selected critical values are tabulated for sample sizes n =5(1)60. The asymptotic normality of the statistic is proved and a comparison is made of the asymptotic efficiency between the statistic and other statistics. The power of the test is studied by simulation. A test for HNBUET in the case of randomly right-censored data is also considered. An application of the proposed test statistic in medical sciences is given.

• Asian Journal of Innovation and Policy
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• v.10 no.3
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• pp.330-354
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• 2021

To know the long-term growth patterns and determinants of successful startups, 15-year (2006-2020) panel data of 252 companies that had a growth rate of over 20% every year in the last three years were used. In the first analysis, statistics on the period required to designate a gazelle company or listed on the stock market were examined. In addition, five long-term growth patterns were presented. In the panel analysis, the R&D intensity, operating profit ratio, size, and age of the company were pointed out as determinants of growth. The operating profit margin and R&D intensity have a positive effect on growth. Gibrat's law was not supported, but an inverted U-shape was observed. Jovanovic's law was confirmed. Although many studies tend not to point to profitability as a determinant of long-term growth, this is an important long-term growth factor of a company. The operating profit ratio was used in this study.

• Communications of Mathematical Education
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• v.33 no.4
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• pp.425-444
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• 2019

Comparing to the U.S. mathematics textbooks, this study examines the opportunity to learn statistical processes represented in mathematics textbooks reflecting 2015 revised curriculum. Analyzing four different kinds of Korean middle school mathematics textbooks and two kinds of corresponding U.S. textbooks for seventh graders, we found that the tasks dealing with all the phases of statistical processes were found only in the U.S. textbooks while not even one task in such a case was not observed in the Korean textbooks. To make matters worse, the proportion of the tasks dealing with only one phase of statistical processes was 93.3% of all the tasks in Korean textbooks. In terms of types of tasks, the types of tasks were very homogeneous in Korean textbooks, usually Types FPR or PR while more various types of tasks were found in the U.S. textbooks such as Types FRI, PRI, FR, or RI. In views of features of each phase in statistical processes, Korean textbooks heavily focused only on some particular statistical behaviors such as 'formulating a problem', 'collecting data', 'transforming data', and 'analyzing a part of data.' The findings of this study provide meaningful implications for improving statistics education and developing mathematics textbooks to enhance students' statistical thinking and problem-solving ability.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.1031-1033
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• 2014

Aim: To investigate the effect of hyperglycemia and hyperinsulinemia on prostate cancer risk. Materials and Methods: This hospital based study was carried out using data retrieved from the register maintained in the Department of Biochemistry of a tertiary care hospital of Kathmandu, Nepal between $31^{st}$ December, 2011 and $31^{st}$ October, 2013. The variables collected were age, serum cholesterol, serum calcium, PSA, fasting blood glucose, serum insulin. Analysis was performed by descriptive statistics and testing of hypothesis using Excel 2003, R 2.8.0, Statistical Package for the Social Sciences (SPSS) for Windows Version 16.0 (SPSS Inc; Chicago, IL, USA) and the EPI Info 3.5.1 Windows Version. Results: Of the total 125 subjects enrolled in our present study, 25 cases were of PCa and 100 were healthy controls. The mean value of fasting plasma glucose was 95.5 mg/dl in cases of prostatic carcinoma and the mean value of fasting plasma insulin was $5.78{\mu}U/ml$ (p value: 0.0001*). The fasting insulin levels ${\mu}U/ml$ were categorized into the different ranges starting from ${\leq}2.75$, >2.75 to ${\leq}4.10$, >4.10 to ${\leq}6.10$, > $6.10{\mu}U/ml$. The maximum number of cases of prostatic carcinoma of fasting insulin levels falls in range of > $6.10{\mu}U/ml$. The highest insulin levels (> $6.10{\mu}U/ml$) were seen to be associated with an 2.55 fold risk of prostatic carcinoma when compared with fasting insulin levels of (< $2.75{\mu}U/ml$). Conclusions: Elevated fasting levels of serum insulin appear to be associated with a higher risk of prostate cancer.

• Journal of Fashion Business
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• v.8 no.4
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• pp.60-67
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• 2004

The purpose of this study was to examine fashion counterfeit purchasing behavior and purchasing intention among Koreans and Americans. 486 female college students were surveyed for this study. For data analysis, descriptive statistics, 2-test, and t-test were used. As the results, generally Korean consumers had purchased more fashion counterfeits than American consumers. There were significantly differences between two groups on 5 fashoin brand counterfeits. That is, handbag of PRADA or LOUIS VUITTON, shoes of Ferragamo, or Gucci, clothing of DKNY, PRADA, or CK, sunglass of Gucci or Channel, and accessories of Agatha, Cartier, or Tiffany were purchased by Korean consumers much more than by U.S consumers. Also, Koreans had more higher purchasing intentions toward fashion counterfeits than Americans except clothing. Based on these results, fashion marketing would be suggested.