• 가정과삶의질연구
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• 제10권2호
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• pp.51-59
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• 1992

Previous studies indicated that unmarried persons are subject to higher mortality than the married, and that the differentials are more marked for male than for females. There are two major approaches to explaining the marital status differentials in mortality ; selection function and protection function of marriage. Following protection fucntion, this study develops the new "instrumental / expressive sex-role" hypothesis in order to explain why marriage protects males more against death. The hypothesis expects that male's instrumental role and female's expressive role have direct effect as well as indirect effect through social integration on sex differential mortality by marital status. for the hypothesis testing, Korea and US vital statistics and census data are used to compute age-specific , age-adjusted mortality rates and their ratios for persons in different marital status. Major findings are as follows. 1)For both Korea and US being married is more advantageous to males than females, ad being widowed, divorced, and separated is more disadvantageous to males, while being never-married is more disadvantageous to females, 2) For Korea, the never married men and women have the highest mortality rates, 3) For US the never married women have the highest mortality rate, while the divorced, separated, and widowed men have the highest mortality rate. Fro both Korea and US data, selection function is rejected, but instrumental/expressive sex-role hypothesis succeeds in accounting for the sex and marital status differential in mortality.

• Communications for Statistical Applications and Methods
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• 제8권3호
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• pp.603-613
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• 2001

A test based on score statistic is derived for detecting homoscedasticity of errors in unbalanced random effects linear model. A small simulation study is performed to investigate the finite sample behaviour of the test statistic which is known to have an asymptotic chi-square distribution under the null hypothesis.

• Communications for Statistical Applications and Methods
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• 제16권1호
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• pp.137-141
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• 2009

We study on selecting the kernel weighting function in smoothing moment conditions for dependent processes. For hypothesis testing in Generalized Method of Moments or Generalized Empirical Likelihood context, we find that smoothing moment conditions by Bartlett kernel delivers smallest size distortions based on empirical Edgeworth expansions of the long-run variance estimator.

• 충청수학회지
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• 제3권1호
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• pp.97-101
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• 1990

For testing a hypothesis $H:{\theta}={\theta}_1$, vs $A:{\theta}={\theta}_2$ (${\theta}_1$ < ${\theta}_2$, we obtain a truncated sequential bayes procedure which minimizes the average sample size between ${\theta}_1$ and ${\theta}_2$.

• Smart Structures and Systems
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• 제15권2호
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• pp.395-408
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• 2015

This study aims to propose a Bayesian approach to consider changes in temperature and vehicle weight as environmental and operational factors for vibration-based long-term bridge health monitoring. The Bayesian approach consists of three steps: step 1 is to identify damage-sensitive features from coefficients of the auto-regressive model utilizing bridge accelerations; step 2 is to perform a regression analysis of the damage-sensitive features to consider environmental and operational changes by means of the Bayesian regression; and step 3 is to make a decision on the bridge health condition based on residuals, differences between the observed and predicted damage-sensitive features, utilizing 95% confidence interval and the Bayesian hypothesis testing. Feasibility of the proposed approach is examined utilizing monitoring data on an in-service bridge recorded over a one-year period. Observations through the study demonstrated that the Bayesian regression considering environmental and operational changes led to more accurate results than that without considering environmental and operational changes. The Bayesian hypothesis testing utilizing data from the healthy bridge, the damage probability of the bridge was judged as no damage.

• 한국과학교육학회지
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• 제17권3호
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• pp.333-343
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• 1997

The purpose of the present study was to investigate an appropriate instructional model in order to remedy students' misconception. As hypotheses of this study, three instructional models, cognitive conflicting, hypothesis testing, and learning cycle models, on biological 'osmosis' concept were tested in 176 high school students. Results of the present study are as follows: 1. All groups used one of three instructional models showed a statistically significant improvement in conceptual change on the 'osmosis' concept between before and after the instruction. In addition, the three hypothesized instructional models were more effective in conceptual change than a traditional expository instruction. 2. There was a statistically significant difference among three experimental groups. Cognitive conflicting model and hypothesis testing model was more effective than learning cycle models. 3. An interviewing after instruction showed that students who had scientific concept on the 'osmosis' through the instruction could effectively apply the concept to other context more than students who had no scientific concept through instruction. The present study indicated that instructional model play an important role on students' conceptual change in science classroom. According to the result of this study, the instruction emphasizing students' active participation in class and scientific reasoning process is more appropriate to remedy misconception that the instruction using students' passive participation in class and expository teaching procedure. This study also indicated that students' concept acquired through instruction is one of important factors to apply it to other context.

• 한국과학교육학회지
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• 제32권3호
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• pp.486-501
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• 2012

The aims of this study are to investigate two main problems for the hypothetico-deduction method and to develop a scientific inquiry model to resolve these problems. The structure of this scientific inquiry model consists of accounts of the context of discovery and justification that the hypothetico-deduction holds as two main problems : 1) the heuristic flaw in the hypothetico-deduction method is that there is no limit to creating hypotheses to explain natural phenomena; 2) Logically, this brings into question affirming the consequent and modus tollens. The features of the model are as follows: first, the generation of hypotheses using an analogical abduction and the selection of hypotheses using consilience and simplicity; second, the expansion phase as resolution for the fallacy of affirming the consequent and the recycle phase as resolution for modus tollens involving auxiliary hypotheses. Finally, we examine the establishment process of Copernicus's Heliocentric Hypothesis and the main role of the history of science for the historical invalidity of this scientific inquiry model based on three examples of If/and/then type of explanation testing suggested by Lawson (International journal of science and Mathematics Education, 2005a, 3(1): 1-5) We claim that this hypotheticho-deduction process involving abduction approach produced favorable in scientific literacy rising for science teacher as well as students.

• 응용통계연구
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• 제4권1호
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• pp.1-11
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• 1991

다변량분산분석이나 판별분석 등에 있어서 검정의 대상이 되는 공분산행렬의 동일성에 대한 붓스트랩방법의 활용을 살펴보았다. 두 모집단의 공분산행렬을 $\Sigma_1, \Sigma_2^$라 하면, 가설 H : $\Sigma_1 = \Sigma_2$은 불변성의 관점에서 $\Sigma = \Sigma_1 \Sigma_2^{-1}$의 고유값들이 모두 1 이라는 것과 동등하다. 본 연구에서는 (1) $\Sigma = \Sigma_1 \Sigma_2^{-1}$의 표본고유값들에 대한 편의를 붓스트랩에 의해 정정하였으며, (2) 이들의 표본분포를 붓스트랩분포로 추정하여 검정에 활용하였으며, (3) 합동붓스트랩에 의해 바플렛의 수정우도비 검정통계량의 분포를 근사하였다.

• 스마트미디어저널
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• 제5권1호
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• pp.30-37
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• 2016

In recent decades, the study of human brain function has dramatically increased thanks to the advent of Functional Magnetic Resonance Imaging. This is a powerful tool which provides a deep view of the activities of the brain. From fMRI data, the neuroscientists analyze which parts of the brain have responsibility for a particular action and finding the common pattern representing each state involved in these tasks. This is one of the most challenges in neuroscience area because of noisy, sparsity of data as well as the differences of anatomical brain structure of each person. In this paper, we propose the use of appropriate discriminant methods, such as Fisher Discriminant Ratio and hypothesis testing, together with strong boosting ability of Adaboost classifier. We prove that discriminant methods are effective in classifying cognitive states. The experiment results show significant better accuracy than previous works. We also show that it is possible to train a successful classifier without prior anatomical knowledge and use only a small number of features.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권4호
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• pp.1193-1215
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• 2021

The measurement of the key product quality index plays an important role in improving the production efficiency and ensuring the safety of the enterprise. Since the actual working conditions and parameters will inevitably change to some extent with time, such as drift of working point, wear of equipment and temperature change, etc., these will lead to the degradation of the quality variable prediction model. To deal with this problem, the selective integrated moving windows based principal component regression (SIMV-PCR) is proposed in this study. In the algorithm of traditional moving window, only the latest local process information is used, and the global process information will not be enough. In order to make full use of the process information contained in the past windows, a set of local models with differences are selected through hypothesis testing theory. The significance levels of both T - test and χ² - test are used to judge whether there is identity between two local models. Then the models are integrated by Bayesian quality estimation to improve the accuracy of quality variable prediction. The effectiveness of the proposed adaptive soft measurement method is verified by a numerical example and a practical industrial process.