• Title/Summary/Keyword: 능력검정

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Power Test of Trend Analysis using Simulation Experiment (모의실험을 이용한 경향성 분석기법의 검정력 평가)

  • Ryu, Yongjun;Shin, Hongjoon;Kim, Sooyoung;Heo, Jun-Haeng
    • Journal of Korea Water Resources Association
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    • v.46 no.3
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    • pp.219-227
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    • 2013
  • Time series data including change, jump, trend and periodicity generally have nonstationarity. Especially, various methods have been proposed to identify the trend about hydrological time series data. However, among various methods, evaluation about capability of each trend test has not been done a lot. Even for the same data, each method may show the different result. In this study, the simulation was performed for identification about the changes in trend analysis according to the statistical characteristics and the capability in the trend analysis. For this purpose, power test for the trend analysis is conducted using Men-Kendall test, Hotelling-Pabst test, t test and Sen test according to the slope, sample size, standard deviation and significance level. As a result, t test has higher statistical power than the others, while Mann-Kendall, Hotelling-Pabst, and Sen tests were similar results.

Evaluation of Procss Capability for Exponential Distribution (지수분포의 공정능력 평가)

  • Hong-Jun Kim;Jin-Soo Kim
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.25 no.6
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    • pp.48-53
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    • 2002
  • 품질보증 부분에서 대부분 통계적 수법들은 기지분포를 가정하여 데이터를 분석하고 있다. 예를 들면 공정능력에서는 정규분포를 가정하고 있고, 신뢰성 분석에서는 지수분포, 대수정규분포 또는 와이블분포 등을 가정하고 있다. 만약 이러한 것들이 가정하는 확률분포와 크게 편의될 때 도출된 결론은 그 유효성을 상실하게 된다. 따라서 공정이 정규분포를 하지 않는다면 정규분포에 기초한 공정능력지수의 사용은 부정확한 공정의 정보를 제시하게 된다. 이러한 문제를 해결하기 위하여 그 사례로 소표본일 경우 정규성의 유무를 Lilliefors 검정통계량으로 검정하였다. 그리고 최우추정량(MLE), 수정적률추정량(MME), 및 적률추정량(ME)을 사용하여 모수추정을 하여 그 각각의 경우에 공정능력지수로 평가하였다. 공정능력지수의 평가는 공정이 지수분포를 하는 경우에 적합한 공정능력지수($C_{pe}$)를 제안하고, 이것의 대안으로써 Pearson 시스템, Johnson 시스템 및 Burr 시스템과도 비교평가 하였다.

A Study on the Development for Qualification Items on Digital Information Application Ability (디지털정보활용능력 관련 자격검정에 관한 연구)

  • Hwang, Seok-Hae;Cho, Jeong-Yoon;Noh, Kyoo-Sung
    • Information Systems Review
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    • v.5 no.1
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    • pp.61-80
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    • 2003
  • In this study, we tried to find qualification items that qualified the processing skill of information and internet application on information and communication industry. The purpose of this research is to detect operation condition of national, private, and many other qualifications using digital information application ability and then developed new qualification items which able to solve problems on present qualification items. Related works and the data analysis for this study were performed and the committee that is composed of qualification item experts, professor, and the person in charge of Korea information & communication institute was held in twice.

Comparison on Probability Plot Correlation Coefficient Test Considering Skewness of Sample for the GEV Distribution (표본자료의 왜곡도 영향을 고려한 GEV 분포의 확률도시 상관계수 검정방법 비교 검토)

  • Ahn, Hyunjun;Shin, Hongjoon;Kim, Sooyoung;Heo, Jun-Haeng
    • Journal of Korea Water Resources Association
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    • v.47 no.2
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    • pp.161-170
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    • 2014
  • It is important to estimate an appropriate quantile for design of hydraulic structure. For this purpose, it is necessary to find the appropriate probability distribution which can represent the sample data well. Probability plot correlation coefficient test as one of goodness-of-fit test, is recently developed and has been known as a simple and powerful method. In this study, probability plot correlation coefficient test statistics using the plotting position considering the coefficients of skewness for the GEV distribution is derived, and represented by the regression equation. Monte-Carlo method is also performed to compare the rejection power between each method. As the results, the probability plot correlation coefficient test which is derived in this study is better than the others. In particular, when sample size is small and distribution has the shape parameter, rejection power of probability plot correlation coefficient test considering the coefficients of skewness is bigger than the others.

Test of randomness for answers arrangement in 2017 College Scholastic Ability Test (2017학년도 대학수학능력시험 영역별 정답배열 임의성 검정)

  • Ahn, Sojin;Lee, Jae Eun;Jang, Dae-Heung
    • The Korean Journal of Applied Statistics
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    • v.30 no.4
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    • pp.503-512
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    • 2017
  • In test with multiple choices, it is necessary to have the position of correct answers of each question spreaded evenly over all the questions in order to minimize the influence of answering tendency of test takers with preference to specific position of multiple choices. The scores of tests with correct answers in specific positions would not reflect exactly the academic aptitude of examinees who do not know correct answers but have the biased answering tendency. In this paper, we have randomness test for the positioning of correct answers at the 2017 College Scholastic Ability Test (CSAT) using Bartels rank test, the Wald-Wolfowitz runs test, the turning point test, the Cox Stuart trend test, the difference sign test and the Mann-Kendall tank test, etc. We also do independence test between the location of correct answer and the allocation of score in each question, for it may result in overestimating the test-taker with specific position preference in marking correct answers.