• Journal of Convergence for Information Technology
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• v.9 no.8
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• pp.268-273
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• 2019

The study was to find out whether the more difficult each activities of daily living(ADLs) is, the more high subjective health status, or health insecurity, is among those in their 65 or older in Seoul and Gyeonggi Province. The subjects were asked up to 1 to 5 points for subjective health status and ADLs. And according to the performance level of each activities of daily living, the order trend was analyzed in four groups (very difficult, difficult, easy, and very easy) by Jonckheere-Terpstra. Order trends were also compared using a linear regression line. Depending on the degree of difficulty in "using toilet," "bathing" and "shopping," the insecurities in subjective health status showed a corresponding order differences. It has been shown that the slope of "using toilet" on a linear regression line is the largest. The more difficult it was to "use toilet," "bathing" and "shopping," the higher the score of health insecurity was.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1B
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• pp.1-11
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• 2010

In this study, To analyzed the monthly long-term change characteristics of Chukwooki rainfall data set (CWK) and modern rain gage rainfall data set (MRG), tests of trend or variation were performed of each data sets using five statistical trend or variation test method. furthermore, changing characteristics of rainfall was analyzed through the accomplishment of the 2-dimensional LOWESS regression (or smoothing) which can consider both annual time-variation and inter-monthly time-variation. From the trend test, it is difficult to confirm that given data sets have significant trends. From the 2-dimensional LOWESS analysis for four rainfall characteristics, after near A.D. 1980, inter-monthly variation width in addition to quantative increment of rainfall are increased rapidly and persistently.

• Journal of the Korean earth science society
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• v.42 no.1
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• pp.76-87
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• 2021

In this study, temporal trend of researches in earthquake with groundwater level, water quality, radon, remote sensing, electrical resistivity, gravity, and geomagnetism was searched from 2001 to 2020, using the journals indexed in Web of Science, and the number of articles published in international journals was counted in relation to the occurrences of earthquakes (≥Mw 5.0, ≥Mw 6.0, ≥Mw 7.0, ≥Mw 8.0, and ≥Mw 9.0). The number of articles shows an increasing trend over the studied period. This is explained by that studies on earthquake precursor and seismic monitoring becomes active in various fields with integrated data analysis through the development of remote sensing technology, progress of measurement equipment, and big data. According to Mann-Kendall and Sen's tests, gravity-related articles exhibit an increasing trend of 1.30 articles/yr, radon-related articles (0.60 articles/yr), groundwater-related articles (0.70 articles/yr), electrical resistivity-related articles (0.25 articles/yr), and remote-sensing-related articles (0.67 articles/yr). By cross-correlation analysis of the number of articles in each field with removing trend effect and the number of earthquakes of ≥Mw 5.0, ≥Mw 6.0, ≥Mw 7.0, ≥Mw 8.0, and ≥Mw 9.0, radon and remote sensing fields exhibit a high cross-correlation with a delay time of one year. In addition, large-scale earthquakes such as the 2004 and 2005 Sumatra earthquake, the 2008 Sichuan earthquake, the 2010 Haiti earthquake, and the 2010 Chile earthquake are estimated to be related with the increase in the number of articles in the corresponding periods.

• The Korean Journal of Applied Statistics
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• v.9 no.2
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• pp.95-108
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• 1996

There are many clinical trials where a large portion of the patients are cured of disease. In such a case, one might be more interested in testing the differences in cure rates rather than other types of differences in failure distribution. For ethical and economic reasons, clinical trials must be repeatedly monitored for evidence of treatment benefit or harm. In this article, we examined by simulation the properties of nonparametric group sequential methods for comparing the cure rates between two treatment groups during the trial in a wide range of alternatives, censoring rates and cure rates.

• Journal of Korea Water Resources Association
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• v.54 no.11
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• pp.999-1009
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• 2021

As the frequency and intensity of extreme weather events due to climate change are increasing in recent years, it is very important to evaluate and analyze climate conditions to manage and respond to the negative effects of climate change in advance. In this study, the trends and characteristics of regional climate change were analyzed by calculating the climate indices for the Chungcheong Province. Annual and monthly UNEP-MP, UNEP-PM and MDM indices were calculated using daily data from 1973-2020 collected from 10 synoptic meteorological stations operated by the Korea Meteorological Administration. The normality of climate data was analyzed through the KS test, and the climate change trend was analyzed by applying the Spearman and Pearson methods. The Chungcheongnam-do region had a relatively humid climate than the Chungcheongbuk-do region, and the annual climate indices showed a dry climate trend in Cheongju and Chungju, while the climate of Seosan and Buyeo was becoming humid. Based on the monthly trend change analysis, a humid climate trend was observed in summer and autumn, while a dry climate trend was observed in spring and winter. Comparison of climate indices during the past (2001-2010) and the recent (2011-2020) years showed a higher decrease in the average climate indices during the last 10 years and a gradually drying climate change trend was recorded.

• Journal of the Korean Data and Information Science Society
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• v.22 no.1
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• pp.9-18
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• 2011

After the launch of PCS in 1997, the mobile telephone industry has achieved a remarkable growth in market share and sales, and substituted for long-distance wire communication market. This study investigates the interrelationships between the two markets in transition and attempts to perform the statistical tests if the diffusion of mobile telephone was the direct factor for the reduction in sales of long-distance communication industry. The evidence of the direct substitution effect between the two markets is not likely to be found. Unlike the general expectations, the test result seems to prove the sustained initial complementary relation for awhile.

• The Korean Journal of Applied Statistics
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• v.24 no.1
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• pp.103-114
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• 2011

Current series for testing stock market cointegrations tend to be restricted to analyzing the relations between stock market prices and may not be able to understand the whole picture of the variations in the stock market system. The nature of the variations in the stock prices, between the countries that experienced economic crisis and those did not, are different for a certain period of time, and accordingly excluding the potentially important variables in the stock market system causes statistical bias. This study considers domestic foreign exchange markets and financial markets in testing for the cointegrating relations of the stock prices in Korea and major investing countries. The results demonstrate the possibility of specification errors unless those markets are included in the statistical modeling process.

• The Korean Journal of Applied Statistics
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• v.24 no.1
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• pp.1-10
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• 2011

This study investigates the dynamic structure of interdependence on the domestic and related major stock markets by employing a statistical framework. Finance theory predicts potential gains by international portfolio diversification if returns from investment in different national stock markets are not perfectly correlated or not cointegrated. The benefit of international diversification is limited when national stock markets are cointegrated because of the limited amount of independent variation by the presence of common factors. The statistical tests suggest that international diversification appears to be favorable after the period of the comovement of the stock prices caused by 1997 Asian financial crisis. The result reflects the increase in overseas investment and purchase of overseas funds after the early 2000's.

• Journal of the Korea Society of Computer and Information
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• v.10 no.6 s.38
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• pp.27-36
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• 2005

Finite failure NHPP models presented in the literature exhibit either constant, monotonic increasing or monotonic decreasing failure occurrence rates Per fault. This Paper Proposes reliability model using the generalized gamma distribution, which can capture the monotonic increasing(or monotonic decreasing) nature of the failure occurrence rate per fault. Equations to estimate the parameters of the generalized gamma finite failure NHPP model based on failure data collected in the form of interfailure times are developed. For the sake of proposing shape parameter of the generalized gamma distribution, used to the special pattern. Data set, where the underlying failure process could not be adequately described by the knowing models, which motivated the development of the gamma or Weibull model. Analysis of failure data set for the generalized gamma modell, using arithmetic and Laplace trend tests . goodness-of-fit test, bias tests is presented.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.493-496
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• 1998

시대가 산업화ㆍ고속화가 되어 감에 따라 우리의 인체는 전자파를 발생하는 물질에 쉽게 노출되어 있다. 전자파가 우리 인체에 미치는 영향은 입증은 되지 않고 있으나, 그 피해가 속속히 발생, 그에 대한 피해 역시 증가하고 있는 추세이다. 이러한 전자파에 대해 선진 각 국에서는 일찍이 국가적인 차원에서의 규제치를 마련하였고, 우리나라에서는 1997년 7월 1일 인체 보호를 위한 전자파 장해 검정수치 설정 및 7개 분야 차폐 의무화를 실시하였다. (중략)