• Title/Summary/Keyword: hypothesis tests

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Statistical Tests for the Lead-Lag Relationship between the Stock Price and the Business Indicator

  • Kim, Tae-Ho;Lee, Sung-Duck;Cho, Joong-Jae
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.1
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    • pp.41-50
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    • 2007
  • This study attempts to test the lead-lag relationship between the stock price and the business indicator in the multivariate context. It additionally investigates the short and long-run dynamic relationships among the four market variables. The hypothesis that the stock price leads the business indicator is found to be rejected for the whole study period. When structural change is considered, the statistical result appears to reflect the reality. The causal relationships among the variables in the former period are simpler than those in the latter period, and the stock price significantly appears to lead the business indicator. On the other hand, the relationship between the stock price and the business indicator in the latter period appears to prove the recent hypothesis of their coincidence.

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The Impact of Global Financial Crisis 2008 on Amman Stock Exchange

  • Ajlouni, Moh'd Mahmoud;Mehyaoui, Wafaa;Hmedat, Waleed
    • Journal of Distribution Science
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    • v.10 no.7
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    • pp.13-22
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    • 2012
  • The effect of the September 2008 global financial crisis weighed heavily on stock markets around the world. The purpose of this study is to empirically investigate the impact of the crisis on Amman Stock Exchange. Event study methodology has been adopted on a period of 24 months, from January 2008 to December 2009. Monthly average abnormal returns across a sample of 52 industrial and services companies have been tested separately. The results reveal that Amman Stock Exchange experienced significant negative abnormal returns in the fourth quarter of the year 2008. However, there were no significant abnormal returns observed thereafter. This means that Amman Stock Exchange managed to overcome its adverse consequences. Since the event study tests for market efficiency, as well, the results show that Amman Stock Exchange reaction is consistent with the semi-strong form of the efficient market hypothesis.

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Designing Statistical Test for Mean of Random Profiles

  • Bahri, Mehrab;Hadi-Vencheh, Abdollah
    • Industrial Engineering and Management Systems
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    • v.15 no.4
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    • pp.432-445
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    • 2016
  • A random profile is the result of a process, the output of which is a function instead of a scalar or vector quantity. In the nature of these objects, two main dimensions of "functionality" and "randomness" can be recognized. Valuable researches have been conducted to present control charts for monitoring such processes in which a regression approach has been applied by focusing on "randomness" of profiles. Performing other statistical techniques such as hypothesis testing for different parameters, comparing parameters of two populations, ANOVA, DOE, etc. has been postponed thus far, because the "functional" nature of profiles is ignored. In this paper, first, some needed theorems are proven with an applied approach, so that be understandable for an engineer which is unfamiliar with advanced mathematical analysis. Then, as an application of that, a statistical test is designed for mean of continuous random profiles. Finally, using experimental operating characteristic curves obtained in computer simulation, it is demonstrated that the presented tests are properly able to recognize deviations in the null hypothesis.

The Test of Stochastic Convergence of Environment Emission and Environmental Kuznets Curve Hypothesis in Asian Developing Countries (아시아 국가들 환경오염배출량의 확률수렴성과 환경쿠즈네츠곡선가설 검정)

  • Kim, Ji Uk
    • Environmental and Resource Economics Review
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    • v.19 no.3
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    • pp.571-595
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    • 2010
  • This research applies an panel data stationarity and stochastic convergence test developed by Carrion-i-Silvestre et al. (2005), which has the advantage of considering multiple structural breaks and the presence of cross-section dependence in order to investigate the hypothesis that relative emission $CO_2$ per capita stochastically converge for 11 Asian countries from 1971~2007. We find that relative emission $CO_2$ per capita is stationary after the structural breaks and cross-section dependence are introduced into the model. We also investigate whether Environmental Kuznets Curve (EKC) hypothesis exists in 11 Asian countries. For EKC test, using the panel cointegration tests of Banerjee and Carrion-i-Silvestre (2006) and Westerlund and Edgerton(2007), we find that relative emission $CO_2$ per capita and relative GDP per capita are cointegrated. However EKC hypothesis in 11 Asian countries is not supported.

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Effects of Hand Moxibustion and Hand Press Pellet on Low Back Pain, Range of Joint Movement, and Depression (요통을 가진 남성 제조업 근로자에 대한 수지 뜸 요법과 압봉자극법 적용 효과)

  • Kim, Yeoun Ok;Choi, Soon Ock;Kim, Jee Won
    • Research in Community and Public Health Nursing
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    • v.30 no.3
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    • pp.336-344
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    • 2019
  • Purpose: This study tries to examine the effects of hand moxibustion and press pellet by applying them to male manufacturing workers with low back pain, and use them to develop nursing interventions for workers. Methods: The data were collected from August to October, 2018, and the subjects were 60 men, processed by using SPSS/WIN 21.0 to perform homogeneity test with $x^2$-, t-, and hypothesis tests with repeated measures, ANOVA and $Scheff{\acute{e}}$ test. Results: Hypothesis 1 that "the experimental group provided with hand moxibustion and hand press pellet would give lower scores for low back pain than the control group" was supported (F=78.71, p<.001). Hypothesis 2 that "the experimental group provided with hand moxibustion and hand press pellet would have a wider range of motion than the control group" was also supported (F=17.44, p<.001). Hypothesis 3 that "the experimental group provided with hand moxibustion and hand press pellet would give lower scores for depression than the control group," again, was supported (F=16.95, p<.001). Conclusion: Hand moxibustion and hand press pellet are effective in relieving low back pain for male workers, in increasing the range of motion, and in decreasing depression.

A Wilcoxon signed-rank test for random walk hypothesis based on slopes (기울기를 이용한 랜덤워크 윌콕슨 부호순위검정)

  • Kim, Tae Yoon;Park, Cheolyong;Kim, Seul Gee;Kim, Min Seok;Lee, Woo Jung;Kwon, Yunji
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.6
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    • pp.1499-1506
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    • 2014
  • Random walk is used for describing random phenomenon in various areas but tests for random walk developed so far are known to suffer from size distortion and low power. Kim et al. (2014) proposed a sign test for unit root (${\rho}=1$) hypothesis based on slopes. This article proposes a Wilcoxon signed rank test based on slopes for unit root hypothesis, and compares it with the augmented Dickey-Fuller test and the sign test by a simulation study. Our results confirm that the nonparametric tests are better than ADF test for small samples like n = 30. The results also show that the sign test is better than the Wilcoxon signed rank test and that for 0 < ${\rho}$ < 1 (-1 < ${\rho}$ < 0), the nonparametric tests suffer from power loss (improvement) as normal error changes to double exponential error.

On the Equality of Two Distributions Based on Nonparametric Kernel Density Estimator

  • Kim, Dae-Hak;Oh, Kwang-Sik
    • Journal of the Korean Data and Information Science Society
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    • v.14 no.2
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    • pp.247-255
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    • 2003
  • Hypothesis testing for the equality of two distributions were considered. Nonparametric kernel density estimates were used for testing equality of distributions. Cross-validatory choice of bandwidth was used in the kernel density estimation. Sampling distribution of considered test statistic were developed by resampling method, called the bootstrap. Small sample Monte Carlo simulation were conducted. Empirical power of considered tests were compared for variety distributions.

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Edge Detection using Statistical Hypothesis Testing

  • Lim, Dong-Hoon;Sung, Sin-Hee
    • Communications for Statistical Applications and Methods
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    • v.6 no.3
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    • pp.893-900
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    • 1999
  • We use statistical tests which are useful for two-sample problem for detecting edges in gray-level images. An edge is detected by examining changes in gray-level value between adjacent pixel neighborhoods. Some experimental results show that nonparametric detectors such as Mann-Whitney test median test and Kolmogorov-Smirnov test perform effectively in both noisy and noise-free images while parametric T test is sensitive to noise.

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Who Would Amend the Procedural Rules in the Legislature, and Why? An Analysis of Legislators' motivations to Propose Amendments of the National Assembly Law in the 19th Korean National Assembly (누가, 왜 국회법을 개정하려 하는가? 제19대 국회 국회법 개정안 발의 분석)

  • Koo, Bonsang;Park, Wonho
    • Korean Journal of Legislative Studies
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    • v.24 no.2
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    • pp.67-99
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    • 2018
  • This study analyzes the revision bills of the National Assembly Law in the 19th National Assembly in which the National Assembly Advancement Act was enacted, with the question "who are involved in the revision of the procedural rules, and what motivates them?" The cosponsor network analysis focusing on primary sponsors of the revision bills shows that the network was constructed by party affiliations. A small number of members with high degree centrality attempted to cooperate with each other at the cosponsoring stage, but the legislation did not pass through the related committee. In addition, this study tests the four competitive hypotheses (the committee hypothesis, the distributive politics hypothesis, the ideological distance hypothesis, and the partisan affiliation hypothesis) about the motivation to propose amendments by using the regression models which include newly measured variables. Only the committee hypothesis and the partisan affiliation hypothesis are empirically supported. This implies that partisan consideration is still significant in amending the National Assembly Law even after the National Assembly Advancement Act, and thus party leaders' willingness to seek bipartisan compromises is at the heart of problem-solving.

Strain Characteristics of Reinforcing materials in the transition zone of slopes (사면의 변이영역에서 보강재의 변형률 특성)

  • 김경태;장대수;장기태;한희수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2003.06a
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    • pp.119-127
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    • 2003
  • For the calculation of internal stability, the hypothesis in conventional design is on the basis of two distinct zones, which are‘active zone’and‘passive zone’. This means that there is an abrupt discontinuous transition from active to passive states across a potential failure line. The existence of a discontinuity of this nature appears physically unreasonable, especially from kinematic considerations. A series of pull-out model tests was undertaken from a wall being rotated about the toe to find the strain distribution mobilized from near the wall face into the deep, stable zone through the centre plane. With this finding of transition zone, the objective of study is aiming at identifying the likely effect of this zone in designing method by comparing with the prevailing design method.

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