• Title/Summary/Keyword: Prior

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Noninformative priors for product of exponential means

  • Kang, Sang Gil;Kim, Dal Ho;Lee, Woo Dong
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.3
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    • pp.763-772
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    • 2015
  • In this paper, we develop the noninformative priors for the product of different powers of k means in the exponential distribution. We developed the first and second order matching priors. It turns out that the second order matching prior matches the alternative coverage probabilities, and is the highest posterior density matching prior. Also we revealed that the derived reference prior is the second order matching prior, and Jeffreys' prior and reference prior are the same. We showed that the proposed reference prior matches very well the target coverage probabilities in a frequentist sense through simulation study, and an example based on real data is given.

Bayesian Analysis for the Ratio of Variance Components

  • Kang, Sang-Gil
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.2
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    • pp.559-568
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    • 2006
  • In this paper, we develop the noninformative priors for the linear mixed models when the parameter of interest is the ratio of variance components. We developed the first and second order matching priors. We reveal that the one-at-a-time reference prior satisfies the second order matching criterion. It turns out that the two group reference prior satisfies a first order matching criterion, but Jeffreys' prior is not first order matching prior. Some simulation study is performed.

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ARMA Model Identification Using the Bayes Factor

  • Son, Young-Sook
    • Journal of the Korean Statistical Society
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    • v.28 no.4
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    • pp.503-513
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    • 1999
  • The Bayes factor for the identification of stationary ARM(p,q) models is exactly computed using the Monte Carlo method. As priors are used the uniform prior for (\ulcorner,\ulcorner) in its stationarity-invertibility region, the Jefferys prior and the reference prior that are noninformative improper for ($\mu$,$\sigma$\ulcorner).

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NONINFORMATIVE PRIORS FOR PARETO DISTRIBUTION : REGULAR CASE

  • Kim, Dal-Ho;Lee, Woo-Dong;Kang, Sang-Gil
    • 한국데이터정보과학회:학술대회논문집
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    • 2003.05a
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    • pp.27-37
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    • 2003
  • In this paper, we develop noninformative priors for two parameter Pareto distribution. Specially, we derive Jeffrey's prior, probability matching prior and reference prior for the parameter of interest. In our case, the probability matching prior is only a first order and there does not exist a second order matching prior. Some simulation reveals that the matching prior performs better to achieve the coverage probability. And a real example will be given.

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Reference Prior and Posterior in the AR(1) Model

  • Lee, Yoon-Jae
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.1
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    • pp.71-78
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    • 2005
  • Recently an important issue in Bayesian methodology is determination of noninformative prior distributions, often required when there is no idea of prior information. In this thesis attention is focused on the development of noninformative priors for stationary AR(1) model. The noninformative priors primarily discussed are the Jeffreys prior, and the reference priors. The remarkable points in the result are that the Jeffreys prior coincides with the reference prior for the case that $\rho$ is the parameter of interest.

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Bayesian Survival Estimation of Pareto Distribution of the Second Kind Based on Type II Censored Data

  • Kim, Dal-Ho;Lee, Woo-Dong;Kang, Sang-Gil
    • Communications for Statistical Applications and Methods
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    • v.12 no.3
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    • pp.729-742
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    • 2005
  • In this paper, we discuss the propriety of the various noninformative priors for the Pareto distribution. The reference prior, Jeffreys prior and ad hoc noninformative prior which is used in several literatures will be introduced and showed that which prior gives the proper posterior distribution. The reference prior and Jeffreys prior give a proper posterior distribution, but ad hoc noninformative prior which is proportional to reciprocal of the parameters does not give a proper posterior. To compute survival function, we use the well-known approximation method proposed by Lindley (1980) and Tireney and Kadane (1986). And two methods are compared by simulation. A real data example is given to illustrate our methodology.

Noninformative priors for the ratio of the scale parameters in the half logistic distributions

  • Kang, Sang-Gil;Kim, Dal-Ho;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.4
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    • pp.833-841
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    • 2012
  • In this paper, we develop the noninformative priors for the ratio of the scale parameters in the half logistic distributions. We develop the first and second order matching priors. It turns out that the second order matching prior matches the alternative coverage probabilities, and is a highest posterior density matching prior. Also we reveal that the one-at-a-time reference prior and Jeffreys' prior are the second order matching prior. We show that the proposed reference prior matches the target coverage probabilities in a frequentist sense through simulation study, and an example based on real data is given.

The Effect of Prior Financial Performance on Organizational Reputation and Earnings Management

  • HUYNH, Quang Linh;NGUYEN, Nguyen Van
    • The Journal of Asian Finance, Economics and Business
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    • v.6 no.4
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    • pp.75-81
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    • 2019
  • The paper aims to investigate the linkage among prior financial performance, organizational reputation and earnings quality. Firstly, it examines the influence of prior financial performance on organizational reputation and on earnings quality. Secondly, this research explores the moderating role that prior financial performance plays in the causal relationship from organizational reputation to earnings quality. Thirdly, the mediating role of organizational reputation in the effect of prior financial performance on earnings quality is analyzed. The empirical findings show that, prior financial performance positively affects both earnings quality and organizational reputation that in turn partly mediates the causal connection from prior financial performance to earnings quality; whereas prior financial performance imposes a positive moderation in the influence of organizational reputation on earnings quality. This research is expected to provide scholars and practitioners with a thorough understanding of the complex link among prior financial performance, organizational reputation and earnings quality. That helps them to deliver good decisions on the investment of suitable resources in maintaining and enhancing their organizational reputation, which assures a higher quality of reported earnings that in turn improves involved stakeholders' confidence in their firm. This likely leads the firms to gain better performance in the future.

Study for the Status and Effectiveness of Science Prior Learning (과학 선행학습의 실태와 그 효과에 대한 연구)

  • Jo, Chang Won;Koo, Min Joo;Park, Jong Keun
    • The Journal of the Convergence on Culture Technology
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    • v.6 no.4
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    • pp.483-492
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    • 2020
  • Considering the fact that many students and parents spend a considerable amount of time and economic power on prior learning and that the environments of internet-based society change rapidly, it is worth examining the status and effectiveness of prior learning. In response, the study surveyed 186 first-year students of A high school in Changwon on the basic status of science prior learning. By the analysis results for the status, 39.8% of the students surveyed said they had experience in prior learning in science. Among the students experienced, 56 students who started science prior learning after the start of winter vacation in the third grade of middle school were analyzed the specific status of science prior learning and the impact of science prior learning on science achievements. The semi-subject form of pre-learning in science showed the highest response rate with 50.0 percent, and the motivation for pre-learning in science was the highest with 33.9 percent improvement in test scores. The confidence and learning intention were positive when conducting prior learning in a semi-subject form, and interest and value were positive when conducting prior learning in a self-directed form. As a result of the survey on the effect of science prior learning, 71.4% of the students who experienced science prior learning showed positive scientific achievement.

Effect of Ti and C Contents on Prior Austenite Grain Size in Ti Added Steels (Ti 첨가강의 Ti와 C 함량에 따른 초기 오스테나이트 입도 변화)

  • Kim, Woo-Jin;Kang, Nam-Hyun;Kim, Sung-Ju;Do, Hyung-Hyup;Nam, Dae-Geun;Cho, Kyung-Mox
    • Korean Journal of Materials Research
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    • v.21 no.4
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    • pp.187-191
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    • 2011
  • Prior austenite grain size plays an important role in the production of high strength hot-rolled steel. This study investigated the effect of Ti and C contents on the precipitates and prior austenite grain size. Steel with no Ti solutes had prior austenite grain size of about 620 ${\mu}m$. The addition of Ti ~ 0.03 wt.% and 0.11 wt.% reduced the prior austenite grain size to 180 ${\mu}m$ and 120 ${\mu}m$, respectively. The amount of Ti required to significantly decrease the prior austenite grain size was in the range of 0.03 wt.%. However, the amount of carbon required to significantly decrease the prior austenite grain size was not present from 0.04 wt.% to 0.12 wt.%. Oxides of Ti ($Ti_2O_3$) were observed as the Ti content increased to 0.03 wt.%. The specimen containing 0.11 wt.% of Ti exhibited the complex carbides of (Ti, Nb) C. The formation of Ti precipitates was critical to reduce the prior austenite grain size. Furthermore, the consistency of prior austenite grain size increased as the carbon and Ti contents increased. During the reheating process of hot-rolled steel, the most critical factor for controlling the prior austenite grain size seems to be the presence of Ti precipitates.