• 제목/요약/키워드: Alternative Hypothesis

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On Sample Size Calculation in Bioequivalence Trials

  • Kang, Seung-Ho
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.90-90
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    • 2003
  • Sample size calculations play an important role in bioequivalence trials. In almost all clinical trials sample size is determined by considering power under the alternative hypothesis. The alternative hypothesis is the hypothesis that we wish to prove with experiments. Hence, in bioequivalence trials the alternative hypothesis is that two formulations are bioequivalent, while the null hypothesis is that the two formulations are not bioequivalent. (omitted)

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임상연구방법론에서 귀무가설과 대립가설, 귀류법에 대한 고찰과 한방이비인후과에서 베이지안 통계학의 활용 (A Study on Null Hypothesis and Alternative Hypothesis, Reduction to Absurdity and Application of Bayesian Statistics in Korean Medicine Otolaryngology)

  • 남승표;배재민;권강
    • 한방안이비인후피부과학회지
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    • 제32권4호
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    • pp.41-61
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    • 2019
  • Background : The current medical statistics used in clinical research are the results of Fisher's significance test and the Neyman-Pearson hypothesis test, which were combined by psychologists. Also, in the philosophical background, it is related to Popper's falsificationism based hypothesis-deductive method and reduction to absurdity. Objectives : This study was designed to find complementary and alternative methods of null hypothesis and alternative hypothesis used for the clinical research methodology of Korean medicine otolaryngology. Methods : The body of this paper was divided into seven part. These are historical background, hypothesis test, hypothesis test method used in the design of clinical study, falsificationism and reduction to absurdity, problem and alternative method of the Neyman-Pearson hypothesis test, diagnosis example of sinusitis differentiation syndromes by Bayesian statistics. Through this process, we found out problems of frequentist statistics and suggested alternative methods. Result & Conclusion : As a solution to the problems of the null hypothesis and the alternative hypothesis, there are effects size, confidence interval, Bayesian statistics and Lakatos methodology of scientific research programmes.

플로지스톤설에서 산소설로의 개념 변화 과정에서 변칙 사례와 대안 가설에 대한 과학자들과 학생들의 반응 비교 (A Comparison of Scientists' and Students' Responses to Discrepant Event and Alternative Hypothesis in the Conceptual Change Processes from the Phlogiston Theory to the Oxygen Theory)

  • 노태희;윤정현;강훈식;강석진
    • 한국과학교육학회지
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    • 제26권7호
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    • pp.798-804
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    • 2006
  • 이 연구에서는 플로지스톤설에서 산소설로의 개념변화 과정에서 제시된 변칙 사례와 대안 가설에 대한 학생들의 반응을 조사하고, 이를 과학자들의 반응과 비교했다. 변칙 사례와 대안 가설에 대한 과학자들의 반응은 과학사 관련 문헌에서 수집했다. 선개념 검사를 실시하여 연소에 대한 목표 오개념을 지닌 중학교 2학년 학생 148명을 선발했다. 학생들에게 변칙 사례와 대안 가설을 제시하고, 이에 대한 학생들의 반응을 조사했다. 연구 결과, 과학자들과 학생들에게서 유사한 반응 유형이 나타났지만, 동시에 명확한 차이점도 있었다. 과학자들은 변칙 사례의 문제점을 밝히고자 노력하는 경향이 있었지만, 학생들은 자신들의 초기이론에 대한 신념을 고수하기 위해 변칙 사례를 거부하거나 배제하는 경향이 있었다. 또한, 대안 가설을 접한 후에 자신의 신념을 바꾸는 학생은 일부에 불과했다.

변칙사례 및 대안가설에 의해 유발된 인지갈등과 비인지적 변인이 개념변화에 미치는 영향 (Influences of Cognitive Conflict and Non-cognitive Variables Induced by Discrepant Event and Alternative Hypothesis on Conceptual Change)

  • 강훈식;곽진하;김유정;노태희
    • 대한화학회지
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    • 제51권1호
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    • pp.56-64
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    • 2007
  • 이 연구에서는 변칙사례 및 대안가설에 의해 유발된 인지갈등과 불안, 주의집중, 노력이 개념변화에 미치는 영향을 조사하였다. 중학교 1학년 학생 470명을 대상으로 선개념 검사를 실시하여 203명의 오개념을 지닌 학생들을 선발하였다. 변칙사례를 제시한 후, 대안가설 제시 전후에 각각 변칙사례에 대한 반응 검사와 불안검사를 실시하였다. CAI 프로그램으로 밀도 개념학습을 실시하였으며, 사후 검사로 주의집중 검사, 노력 검사, 개념 검사를 실시하였다. 연구 결과, 변칙사례에 의해 유발된 인지갈등(사전 인지갈등)은 대안가설 제시 후 증가하였다. 사전 인지갈등은 변칙사례와 대안가설에 의해 유발된 인지갈등(사후 인지갈등)에만 직접적인 영향을 주었으며, 사후 인지갈등은 개념변화에 직접적으로 긍정적인 영향을 주었다. 변칙사례에 의해 유발된 불안(사전 불안)은 대안가설 제시 후 감소하였다. 사전 불안은 변칙사례와 대안가설에 의해 유발된 불안(사후 불안)에만 직접적인 영향을 주었으며, 사후 불안은 노력을 통해 개념변화에 부정적인 영향을 주었다. 주의집중은 개념변화에 직접적으로 또는 노력을 경유하여 긍정적인 영향을 주었다. 이런 결과는 개념변화 수업에서 변칙사례와 대안가설을 함께 제시하는 전략이 변칙사례만 제시하는 전략보다 인지갈등을 더욱 유발하거나 불안을 감소시켜 학생들이 개념학습 과정에 보다 능동적이고 적극적으로 참여하도록 유도함으로써 개념변화를 촉진할 가능성을 시사한다.

Multivariate Analysis of Variance for Fuzzy Data

  • Kang, Man-Ki;Han, Sung-Il
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제4권1호
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    • pp.97-100
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    • 2004
  • We propose some properties of fuzzy multivariate analysis of variance by fuzzy vector operation with agreement index. We deals fuzzy null hypotheses and fuzzy alternative hypothesis and define the agreement index for the grades of the judgements that the hypothesis is rejection or acceptance. Finally, we provide an example to evaluate the judgements.

Computing Fractional Bayes Factor Using the Generalized Savage-Dickey Density Ratio

  • Younshik Chung;Lee, Sangjeen
    • Journal of the Korean Statistical Society
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    • 제27권4호
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    • pp.385-396
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    • 1998
  • A computing method of fractional Bayes factor (FBF) for a point null hypothesis is explained. We propose alternative form of FBF that is the product of density ratio and a quantity using the generalized Savage-Dickey density ratio method. When it is difficult to compute the alternative form of FBF analytically, each term of the proposed form can be estimated by MCMC method. Finally, two examples are given.

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Test of the Hypothesis based on Nonlinear Regression Quantiles Estimators

  • Choi, Seung-Hoe
    • Journal of the Korean Data and Information Science Society
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    • 제14권2호
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    • pp.153-165
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    • 2003
  • This paper considers the likelihood ratio test statistic based on nonlinear regression quantiles estimators in order to test of hypothesis about the regression parameter $\theta_o$ and derives asymptotic distribution of proposed test statistic under the null hypothesis and a sequence of local alternative hypothesis. The paper also investigates asymptotic relative efficiency of the proposed test to the test based on the least squares estimators or the least absolute deviation estimators and gives some examples to illustrate the application of the main result.

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AESA 레이더 최대탐지거리의 통계적 접근 (Statistical Approach for AESA Radar Maximum Detection Range)

  • 탁대석;신경수
    • 시스템엔지니어링학술지
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    • 제15권1호
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    • pp.43-50
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    • 2019
  • Statistical hypothesis tests are important for quantifying answers to questions about samples of data. The Step Process of Statistical Hypothesis Testing; state the null hypothesis, State the alternate hypothesis, State the alpha level, Find the z-score associated with alpha level, Find the test statistic using this formula, If the calculated t distribution value from the data is larger than the t distribution value of alpha level, then you are in the Rejection region and you can reject the Null Hypothesis with ($1-{\alpha}$) level of confidence.

Impostor Detection in Speaker Recognition Using Confusion-Based Confidence Measures

  • Kim, Kyu-Hong;Kim, Hoi-Rin;Hahn, Min-Soo
    • ETRI Journal
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    • 제28권6호
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    • pp.811-814
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    • 2006
  • In this letter, we introduce confusion-based confidence measures for detecting an impostor in speaker recognition, which does not require an alternative hypothesis. Most traditional speaker verification methods are based on a hypothesis test, and their performance depends on the robustness of an alternative hypothesis. Compared with the conventional Gaussian mixture model-universal background model (GMM-UBM) scheme, our confusion-based measures show better performance in noise-corrupted speech. The additional computational requirements for our methods are negligible when used to detect or reject impostors.

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Utterance Verification Using Search Confusion Rate and Its N-Best Approach

  • Kim, Kyu-Hong;Kim, Hoi-Rin;Hahn, Min-Soo
    • ETRI Journal
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    • 제27권4호
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    • pp.461-464
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    • 2005
  • Recently, a variety of confidence measures for utterance verification has been studied to improve speech recognition performance by rejecting out-of-vocabulary inputs. Most of the conventional confidence measures for utterance verification are based primarily on hypothesis testing or an approximated posterior probability, and their performances depend on the robustness of an alternative hypothesis or the prior probability. We introduce a novel confidence measure called a search confusion rate (SCR), which does not require an alternative hypothesis or the approximation of posterior probability. Our confusion-based approach shows better performance in additive noise-corrupted speech as well as in clean speech.

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