• Title/Summary/Keyword: Prior Test

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Noninformative Priors for Step Stress Accelerated Life Tests in Exponential Distribution

  • Lee, Woo-Dong;Pak, Hong-Kyung
    • Proceedings of the Korea Society for Industrial Systems Conference
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    • 2009.05a
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    • pp.107-113
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    • 2009
  • This paper deals with noninformative priors for such as Jeffres' prior, reference prior and probability matching prior for scale parameter of exponential distribution when the data are collected in multiple step stress accelerated life tests. We find the noninformative priors for this model and show that the reference prior satisfies first order matching criterion. Using artificial data, we perform Bayesian analysis for proposed priors.

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The Useful Techniques to Determine the Prior Odds and the Likelihood Ratios Bayesian Processor in Built-In-Test System

  • Yoo, Wang-Jin;Kim, Kyeong Taek
    • Journal of Korean Society for Quality Management
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    • v.24 no.1
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    • pp.61-72
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    • 1996
  • It is very important to determine the likelihood ratios and the prior odds for designing a Bayesian processor in Built-In-Test system. Using traditional statistics, it is not difficult to determine the initial prior odds from the field data. For a newly designed system, development testing data or laboratory testing data could be used to replace field data. The likelihood ratios which playa key role in the Bayesian processor must be carefully determined, based on laboratory testing and statistical techniques. In this paper, expressing and determining the likelihood ratios by Geometric areas, Test, and Analytical method will be presented.

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Children's Generating Hypotheses on the Pendulum Motion: Roles of Abductive Reasoning and Prior Knowledge (진자운동에서 아동의 가설 생성: 귀추와 선지식의 역할)

  • Joeng, Jin-Su;Park, Yun-Bok;Yang, Il-Ho;Kwon, Yong-Ju
    • Journal of the Korean earth science society
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    • v.24 no.6
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    • pp.524-532
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    • 2003
  • The purpose of the present study was to test the hypothesis that student's abductive reasoning skills play an important role in the generation of hypotheses on pendulum motion tasks. To test the hypothesis, a hypothesis-generating test on the pendulum motion and a prior knowledge test about the length of the pendulum motion were developed and administered to a sample of 5th grade children. A significant number of subjects who have the prior knowledge about the length of the pendulum motion failed to apply that prior knowledge to generate a hypothesis on a swing task. These results showed that students' failure in hypothesis-generating was related to their deficiency in abductive reasoning ability, rather than the simple lack of prior knowledge. Furthermore, children's successful generating hypothesis should be required their abductive reasoning skills as well as prior knowledge. Therefore, this study supports the notion that abductive reasoning ability beyond prior knowledge plays an important role in the process of hypothesis-generation. This study suggests that science education should provide teaching about abdctive reasoning as well as scientific declarative knowledge for developing children's hypothesis-generating skills.

SEGMENTATION WITH SHAPE PRIOR USING GLOBAL AND LOCAL IMAGE FITTING ENERGY

  • Terbish, Dultuya;Kang, Myungjoo
    • Journal of the Korean Society for Industrial and Applied Mathematics
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    • v.18 no.3
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    • pp.225-244
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    • 2014
  • In this work, we discuss segmentation algorithms based on the level set method that incorporates shape prior knowledge. Fundamental segmentation models fail to segment desirable objects from a background when the objects are occluded by others or missing parts of their whole. To overcome these difficulties, we incorporate shape prior knowledge into a new segmentation energy that, uses global and local image information to construct the energy functional. This method improves upon other methods found in the literature and segments images with intensity inhomogeneity, even when images have missing or misleading information due to occlusions, noise, or low-contrast. We consider the case when the shape prior is placed exactly at the locations of the desired objects and the case when the shape prior is placed at arbitrary locations. We test our methods on various images and compare them to other existing methods. Experimental results show that our methods are not only accurate and computationally efficient, but faster than existing methods as well.

Bayesian Test for Equality of Coefficients of Variation in the Normal Distributions

  • Lee, Hee-Choon;Kang, Sang-Gil;Kim, Dal-Ho
    • 한국데이터정보과학회:학술대회논문집
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    • 2003.10a
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    • pp.49-56
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    • 2003
  • When X and Y have independent normal distributions, we develop a Bayesian testing procedure for the equality of two coefficients of variation. Under the reference prior of the coefficient of variation, we propose a Bayesian test procedure for the equality of two coefficients of variation using fractional Bayes factor. A real data example is provided.

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Bayesian Test for Equality of Coefficients of Variation in the Normal Distributions

  • Lee, Hee-Choon;Kang, Sang-Gil;Kim, Dal-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.14 no.4
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    • pp.1023-1030
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    • 2003
  • When X and Y have independent normal distributions, we develop a Bayesian testing procedure for the equality of two coefficients of variation. Under the reference prior of the coefficient of variation, we propose a Bayesian test procedure for the equality of two coefficients of variation using fractional Bayes factor. A real data example is provided.

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Prediction model for prior austenite grain size in low-alloy steel weld HAZ (용접열영향부 호스테나이트 결정립 크기 예측 모델링)

  • 엄상호;문준오;이창희;윤지현;이봉상
    • Proceedings of the KWS Conference
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    • 2003.05a
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    • pp.43-45
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    • 2003
  • The empirical model for predicting the prior austenite grain size in low-alloy steel weld HAZ was developed through examining the effect of alloying element. The test alloys were made by vacuum induction melting. Grain growth behaviors were observed and analyzed by isothermal grain growth test and subsequent metallography. As a result, it was found that the grain growth might be controlled by grain boundary diffusion and the empirical model for grain growth was presented.

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Prior Thinking and Posterior Thinking Formation of Children and Adolescents In Sinking Objects (물체의 수중낙하에 대한 아동 및 청소년의 사전생각과 사후생각 형성)

  • 김헤라;유안진
    • Journal of the Korean Home Economics Association
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    • v.40 no.5
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    • pp.39-51
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    • 2002
  • The purpose of this study is to investigate prior thinking and posterior thinking formation of children and adolescents in sinking objects. The subjects consisted of twenty eight, 9- and 11-year old children and fourteen, 13-year old adolescents selected from one elementary school and two middle schools. The transcripts were analyzed to classify children and adolescents'prior thinking and posterior thinking frequency, reasoning response(evidence based response, idea based response) and reasoning method(valid method, invalid method). The data were analyzed by frequency, percentile, mean and standard deviation,1 test, ANOVA. Major findings were as followings: 1. Children and adolescents have already had prior thinking in sinking objects. 2. Children and adolescents applies their prior thinking to posterior thinking formation process. 3. There were significant differences in children and adolescent'posterior thinking formation process, especially choices in objects and reasoning methods depending on age. 4. There were significant differences in children and adolescents'reasoning response depending on presented evidences types.5. Through the experimentation, children and adolescents'prior thinking was different from their posterior thinking. There were significant differences in differences between the prior thinking and posterior thinking depending on age.

Comparing Job Satisfaction with Professional Self-Concept of RN-BSN Students (간호학사 특별과정생의 직업만족도와 전문직 자아개념)

  • Kim Chun-Gil;Noh Choon-Hee
    • The Journal of Korean Academic Society of Nursing Education
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    • v.5 no.2
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    • pp.250-266
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    • 1999
  • This study was conducted to compare the level of RN-BSN students' job satisfaction and professional self-concept (PSCNI) prior to RN-BSN course and upon graduation The study was designed to investigate the degree of job satisfaction and PSCNI, and to test the correlation between job satisfaction and professional self-concept. The subjects were 68 students in Chunchon, who entered to H University (RN-BSN course) in March 1997. The data was gathered by self-reported questionnaire job satisfaction(48 items) and professional self-concept nurses instrument (PSCNI: 27 items) The instruments used for this study were the nurse Job satisfaction scale developed by Stamps et al., and Arthur's PSCNI. The reliability of two questionnaires were relatively high (Job satisfaction Cronbach's $\alpha$=0.88, 0.89, PSCNI Cronbach's $\alpha$=0.80, 0.96) The data was analyzed frequency, mean, t-test, ANOVA, Duncan's multiple range test, Pearson's corelation, and multiple regression analysis through SAS program. Research findings were as follows : 1. The average item score of job satisfaction was 119.50(prior to RN-BSN course) 124.16 (upon graduation). PSCNI' average item score was 75.37/77.21 at each. 2. The job satisfaction scores were significantly higher at the graduation than at the entrance(t=2,10, P=.040). But PSCNI's scores had no significant difference. 3. The relationship between job satisfaction and PSCNI of entering time was high R=.60, P=.000) The relationship of the two at graduation time was not high(R=.29, P=.018). 4. The factors contributing to the job satisfaction & PSCNI as follow: job satisfaction(prior to RB-BSN course), PSCNI(prior to RB-BSN course), The factors contributing to the job satisfaction & PSCNI were as follow: PSCNI(prior to RN-BSN course) In conclusion, we recognized that RN-BSN course influenced job satisfaction of students. Also this study Eave a information for necessity to develop curricula promoting PSCNI. Nurse-educator should explore further research to enlighten the nursing profession.

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A Comparative Study of the Effects of Gibbs Smoothing Priors in Bayesian Tomographic Reconstruction (Bayesian Tomographic 재구성에 있어서 Gibbs Smoothing Priors의 효과에 대한 비교연구)

  • Lee, S.J.
    • Proceedings of the KOSOMBE Conference
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    • v.1997 no.05
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    • pp.279-282
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    • 1997
  • Bayesian reconstruction methods for emission computed tomography have been a topic of interest in recent years, partly because they allow for the introduction of prior information into the reconstruction problem. Early formulations incorporated priors that imposed simple spatial smoothness constraints on the underlying object using Gibbs priors in the form of four-nearest or eight-nearest neighbors. While these types of priors, known as "membrane" priors, are useful as stabilizers in otherwise unstable ML-EM reconstructions, more sophisticated prior models are needed to model underlying source distributions more accurately. In this work, we investigate whether the "thin plate" model has advantages over the simple Gibbs smoothing priors mentioned above. To test and compare quantitative performance of the reconstruction algorithms, we use Monte Carlo noise trials and calculate bias and variance images of reconstruction estimates. The conclusion is that the thin plate prior outperforms the membrane prior in terms of bias and variance.

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