• Title/Summary/Keyword: Hypothesis Tests

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Test and Analysis for Comovement-Locomotive Hypothesis (동조화 현상의 견인차 가설 검정과 분석)

  • Kim, Tae-Ho
    • The Korean Journal of Applied Statistics
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    • v.24 no.2
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    • pp.239-251
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    • 2011
  • The need for statistical analysis to discern the existence and the type of international business comovement has increased as business and economic variations in one country is directly transmitted to business and financial market conditions in another without a long lag. This study performs the statistical tests for th locomotive hypothesis to understand the structural character of the long-run mechanism among Korea-US current and future business movements and the domestic stock market. The U.S. future business prospect, rather than the US current and the domestic current and future business conditions, appears to signi cantl a ect the domestic stock market movement.

Developing of Exact Tests for Order-Restrictions in Categorical Data (범주형 자료에서 순서화된 대립가설 검정을 위한 정확검정의 개발)

  • Nam, Jusun;Kang, Seung-Ho
    • The Korean Journal of Applied Statistics
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    • v.26 no.4
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    • pp.595-610
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    • 2013
  • Testing of order-restricted alternative hypothesis in $2{\times}k$ contingency tables can be applied to various fields of medicine, sociology, and business administration. Most testing methods have been developed based on a large sample theory. In the case of a small sample size or unbalanced sample size, the Type I error rate of the testing method (based on a large sample theory) is very different from the target point of 5%. In this paper, the exact testing method is introduced in regards to the testing of an order-restricted alternative hypothesis in categorical data (particularly if a small sample size or extreme unbalanced data). Power and exact p-value are calculated, respectively.

The Impact of Foreign Exchange Rates on International Travel: The Case of South Korea

  • Lee, Jung-Wan
    • Journal of Distribution Science
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    • v.10 no.9
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    • pp.5-11
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    • 2012
  • Purpose - The objective of the paper is to explain both the price sensitivity of international tourists to South Korea and the price sensitivity of Korean tourists to international travel. The study examines long-run equilibrium relationships and Granger causal relationships between foreign exchange rates and inbound and outbound tourism demand in South Korea. Research design/ data / methodology - The study employs monthly time series data from January 1990 to September 2010. The paper examines the long-run equilibrium relationship using the Johansen cointegration test approach after unit root tests. The short-run Granger causality was tested using the vector error correction model with the Wald test. Results - Hypothesis 1 testing whether there is a long-run equilibrium relationship between exchange rates, inbound and outbound tourism demand is supported. Hypothesis 2 testing whether exchange rates lead to a change in touristarrivals and expenditure is not supported. Hypothesis 3 testing whether exchange rates lead to a change in tourist departures and expenditure is supported. Conclusions - The findings of this study show that the impacts of tourism price competitiveness are changing quite significantly with regard to destination competitiveness. In other words, the elasticity of tourism price over tourism demand has been moderated.

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On the Cointegrating Relationship between Stock Prices and Earnings

  • Nam, Doo-Woo
    • Korean Business Review
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    • v.20 no.2
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    • pp.1-13
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    • 2007
  • The purpose of this study is to investigate a simple present value model Involving earnings (i.e., the earnings discount model) that presumes a relationship between stock prices and earnings. The model suggests a simple linear equilibrium relationship between stock prices and earnings. The tests for cointegration render strong support for the cointegration hypothesis between stock prices (Pt) and earnings (Xt) even at the one-percent significance level. The tests are based on residuals from a cointegrating regression of Pt on Pt+l + Xt. This suggests that there is a stable long-nu equilibrium relationship between stock prices and earnings. The results of the tests lead to the acceptance of the present value model of stock prices involving earnings.

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Large tests of independence in incomplete two-way contingency tables using fractional imputation

  • Kang, Shin-Soo;Larsen, Michael D.
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.4
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    • pp.971-984
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    • 2015
  • Imputation procedures fill-in missing values, thereby enabling complete data analyses. Fully efficient fractional imputation (FEFI) and multiple imputation (MI) create multiple versions of the missing observations, thereby reflecting uncertainty about their true values. Methods have been described for hypothesis testing with multiple imputation. Fractional imputation assigns weights to the observed data to compensate for missing values. The focus of this article is the development of tests of independence using FEFI for partially classified two-way contingency tables. Wald and deviance tests of independence under FEFI are proposed. Simulations are used to compare type I error rates and Power. The partially observed marginal information is useful for estimating the joint distribution of cell probabilities, but it is not useful for testing association. FEFI compares favorably to other methods in simulations.

A Study on Goodness of Fit Test in Accelerated Life Tests (가속수명시험에 대한 적합도 검정에 관한 연구)

  • Lee, Woo-Dong;Cho, Geon-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.7 no.1
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    • pp.37-46
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    • 1996
  • In this paper, we introduce the goodness of fit test procedure for lifetime distribution using step stress accelerated lifetime data. Using the nonpapametric estimate of acceleration factor, we prove the strong consistence of empirical distribution function under null hypothesis. The critical vailues of Kolmogorov-Smirnov, Anderson-Darling, Cramer-von Mises statistics are computed when the lifetime distibution is assumed to be exponential and Weibull. The power of test statistics are compared through Monte-Cairo simulation study.

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Test of Exponentiality in Step Stress Accelerated Life test Model based on Kullback­Leibler Information Function (쿨백­라이블러 정보함수 이용한 단계 스트레스 가속수명모형의 지수성 검정)

  • 박병구;윤상철
    • Journal of Korean Society for Quality Management
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    • v.31 no.4
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    • pp.194-202
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    • 2003
  • In this paper, we propose goodness of fit test statistics for exponentiality in accelerated life tests data based on Kullback­Leibler information functions. This acceleration model is assumed to be a tampered random variable model. The procedure is applicable when the exponential parameter using the data from accelerated life tests is or is not specified under null hypothesis. And we compare the power of the proposed test statistics with Kolmogorov­Smirnov, Cramer von Mises and Anderson­Darling statistics in the small sample.

Statistically Proper Multiple Range Tests for a Within Subject Factor in a Repeated Measures Design

  • Park, Cheol-Yong;Park, Sang-Bum
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.2
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    • pp.525-534
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    • 2007
  • It is a common practice in many research areas that multiple range tests for a between subject factor such as Tukey are applied to a within subject factor in a repeated measures design. Tukey procedure, however, sometimes detects no pairs with different means even when the hypothesis of all equal level means is rejected. This study attempts to provide a rationale for the proposition that Tukey is inappropriate post hoc procedure for a within subject factor in which the observations are correlated. We introduce two multiple range tests, Bonferroni and Scheffe, for a within subject factor and show that Bonferroni is more appropriate than Scheffe for pairwise multiple comparisons. Subsequent simulation study indicates that Tukey has significantly less power than Bonferroni in detecting actual difference between means of some pairs when the observations of a within subject factor are highly correlated.

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k-Sample Rank Tests for Umbrella Location-Scale Alternatives (k-표본 우산형 위치-척도 대립가설에 대한 순위검정법의 연구)

  • Hee Moon Park
    • The Korean Journal of Applied Statistics
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    • v.7 no.2
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    • pp.159-171
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    • 1994
  • Some rank score tests are proposed for testing the equality of all sampling distribution functions against umbrella location-scale alternatives in k-sample problem. Only the case of known peak $\ell$ is considered. Under the null hypothesis and a contiguous sequence of unbrella location-scale alternatives, the asymptotic properties of the proposed test statistics are investigated. Also, the asymptotic local powers are compared with each others. The results show that the tests based on the Chen-Wolfe rank analogue statistic are more powerful than others for unequally spaced umbrella location-scale alternatives and robust.

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Statistical Tests for Edg Detection (에지 검출을 위한 통계적 검정법)

  • Im, Dong-Hun;Seong, Sin-Hui
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.3
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    • pp.1021-1024
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    • 2000
  • In this paper we describe a nonparametric Wilcoxon test and a parametric Z test based on statistical hypothesis testing for the detection of edges. We use the threshold determined by specifying significance level $\alpha$, while Bovik, Huang and Munson[4] consider the range of possible values of test statistics for the threshold. From the experimental results of edge detection, the Z method performs sensitively to the noisy image, while the Wilcoxon method is robust over both noisy nd noise-free images. Comparison with our statistical tests and Sobel operator shows that our tests perform more effectively in both noisy and noise-free images.

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