• Journal of the Korean Data and Information Science Society
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• v.20 no.2
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• pp.261-272
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• 2009

Kolmogorov-Smirnov (K-S) statistic has been widely used for testing homogeneity of two distributions in the credit rating models. Joseph (2005) used K-S statistic to obtain validation criteria which is most well-known. There are other homogeneity test statistics such as the Cramer-von Mises, Anderson-Darling, and Watson statistics. In this paper, these statistics are introduced and applied to obtain criterion of these statistics by extending Joseph (2005)'s work. Another set of alternative criterion is suggested according to various sample sizes, type a error rates, and the ratios of bads and goods by using the simulated data under the similar situation as real credit rating data. We compare and explore among Joseph's criteria and two sets of the proposed criterion and discuss their applications.

• Korea Trade Review
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• v.47 no.2
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• pp.31-46
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• 2022

The purpose of this study is to measure the degree of discrepancies in the bilateral trade data between South Korea and its five major trade partners and to identify the key factors causing the discrepancies. By analyzing statistics based on the CIF/FOB ratio estimation and taking into consideration the trade flow via Hong Kong, the study finds that the discrepancies in South Korea's trade data with the US, Vietnam, and Japan are insignificant. In case of Hong Kong, however, the value of South Korea's import from Hong Kong is extensively inconsistent with Hong Kong's export to South Korea(i.e. the mirror data) while the value of South Korea's export to Hong Kong generally corresponds to its mirror data. Such discrepancies are caused by differences in recording re-exports, which are often found in the trade flow via entrepôt economics including Hong Kong. Meanwhile, discrepancies in reported bilateral trade flows between South Korea and People's Republic of China(PRC) remain relatively marginal. The discrepancy of statistics between South Korea as the exporter and PRC as the importer is mainly caused by the trade flow via Hong Kong. On the other hand, the discrepancy of statistics between South Korea as the importer and PRC as the exporter is assumably due to the differences in attribution of trade partners.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.6
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• pp.592-599
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• 2015

In big data environment, we need new approach for big data analysis, because the characteristics of big data, such as volume, variety, and velocity, can analyze entire data for inferring population. But traditional methods of statistics were focused on small data called random sample extracted from population. So, the classical analyses based on statistics are not suitable to big data analysis. To solve this problem, we propose an approach to efficient big data analysis. In this paper, we consider a big data analysis using principal component analysis, which is popular method in multivariate statistics. To verify the performance of our research, we carry out diverse simulation studies.

• Women's Health Nursing
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• v.28 no.4
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• pp.348-357
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• 2022

Purpose: This study aimed to identify maternal, infant, and perinatal mortality using the national population data of South Korea between 2018 and 2020, and to analyze mortality rates according to characteristics such as age, date of death, and cause of death in each group. This study updates the most recent study using 2009 to 2017 data. Methods: Analyses of maternal, infant, and perinatal mortality were done with data identified through the supplementary investigation system for cases of death from the Census of Population Dynamics data provided by Statistics Korea from 2018 to 2020. Results: Between 2018 and 2020, a total of 99 maternal deaths, 2,427 infant deaths, and 2,408 perinatal deaths were identified from 901,835 live births. The maternal mortality ratio was 11.3 deaths per 100,000 live births in 2018; it decreased to 9.9 in 2019 but increased again to 11.8 in 2020. The maternal mortality ratio increased steeply in women over the age of 40 years. An increasing trend in the maternal mortality ratio was found for complications related to the puerperium and hypertensive disorders. Both infant and perinatal mortality continued to decrease, from 2.8 deaths per 1,000 live births in 2018 to 2.5 in 2020 and from 2.8 in 2018 to 2.5 in 2020, respectively. Conclusion: Overall, the maternal, infant, and perinatal mortality statistics showed improvements. However, more attention should be paid to women over 40 years of age and specific causes of maternal deaths, which should be taken into account in Korea's maternal and child health policies.

• 한국데이터정보과학회:학술대회논문집
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• 2006.04a
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• pp.155-161
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• 2006

To enhance the interest and comprehension of learners studying Statistics. The program which learners can use is needed. With the help of this program, the interest and concentration of the learners can be enhanced, and the effects of the study of Statistics can be maximized, through the convenience of calculation to the theoretical contents of Statistics, various graphs, the, simulation.

• Communications for Statistical Applications and Methods
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• v.2 no.2
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• pp.184-197
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• 1995

An objective and one-step detection procedure of multiple outliers is suggested by using the gaps of the order statistics. The detection procedure can be used as a routine outlier detection method of a statistical analysis computer program. The procedure is applied to some examples including the data selected by Kitagawa.

• Journal of the Korean Data and Information Science Society
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• v.14 no.2
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• pp.187-199
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• 2003

We deal with the problem of testing a sequence of independent normal random variables with constant, known or unknown, variance for no change in mean versus alternatives with a single change-point. Various tests based on the likelihood ratio and recursive residuals, score statistics and cusums are studied. Proposed tests are modified version of Buckley's cusum statistics. A comparison study of various change-point test statistics is done by Monte Carlo simulation with S-plus software.

• Journal of the Korean Data and Information Science Society
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• v.14 no.3
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• pp.653-660
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• 2003

In this paper, we prove that the transformed sample Lorenz curve, normalized sample Lorenz curve, and the test statistics for testing of normality based on the normalized sample Lorenz curve and the modified Lorenz curve which were introduced by Kang and Cho (2001a, 2002) are location and scale invariant statistics.

• School Mathematics
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• v.3 no.1
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• pp.109-129
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• 2001

The concern of this paper is to provide learning opportunities to participate in the class of statistics with interest for the students who dislike mathematics and especially find difficulty in understanding statistics. The students were encouraged to arrange data collected in their daily life by the use of spreadsheet program and to interpret the result of data with graphs, so that they could have a great interest in statistics and make steady progress in their voluntary study. The further study to use computers in teaching mathematics should be continued and recommended in the rapid age of information and knowledge-based.

• The Korean Journal of Applied Statistics
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• v.25 no.5
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• pp.821-827
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• 2012

In this study, we propose a new nonparametric test procedure for the multivariate data. In order to accommodate the generalized alternatives for the multivariate case, we construct test statistics via-values with some useful combining functions. Then we illustrate our procedure with an example and compare efficiency among the combining functions through a simulation study. Finally we discuss some interesting features related with the new nonparametric test as concluding remarks.