• 제목/요약/키워드: posterior expected loss

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Robust Bayesian Inference in Finite Population Sampling under Balanced Loss Function

  • Kim, Eunyoung;Kim, Dal Ho
    • Communications for Statistical Applications and Methods
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    • 제21권3호
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    • pp.261-274
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    • 2014
  • In this paper we develop Bayes and empirical Bayes estimators of the finite population mean with the assumption of posterior linearity rather than normality of the superpopulation under the balanced loss function. We compare the performance of the optimal Bayes estimator with ones of the classical sample mean and the usual Bayes estimator under the squared error loss with respect to the posterior expected losses, risks and Bayes risks when the underlying distribution is normal as well as when they are binomial and Poisson.

Robust Bayesian inference in finite population sampling with auxiliary information under balanced loss function

  • Kim, Eunyoung;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • 제25권3호
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    • pp.685-696
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    • 2014
  • In this paper, we develop Bayesian inference of the finite population mean with the assumption of posterior linearity rather than normality of the superpopulation in the presence of auxiliary information under the balanced loss function. We compare the performance of the optimal Bayes estimator under the balanced loss function with ones of the classical ratio estimator and the usual Bayes estimator in terms of the posterior expected losses, risks and Bayes risks.

Improved Estimation of Poisson Menas under Balanced Loss Function

  • Chung, Younshik
    • Communications for Statistical Applications and Methods
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    • 제7권3호
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    • pp.767-772
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    • 2000
  • Zellner(1994) introduced the notion of a balanced loss function in the context of a general liner model to reflect both goodness of fit and precision of estimation. We study the perspective of unifying a variety of results both frequentist and Bayesian from Poisson distributions. We show that frequentist and Bayesian results for balanced loss follow from and also imply related results for quadratic loss functions reflecting only precision of estimation. Several examples are given for Poisson distribution.

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A Bayesian Approach to Linear Calibration Design Problem

  • Kim, Sung-Chul
    • 한국경영과학회지
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    • 제20권3호
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    • pp.105-122
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    • 1995
  • Based on linear models, the inference about the true measurement x$_{f}$ and the optimal designs x (nx1) for the calibration experiments are considered via Baysian statistical decision analysis. The posterior distribution of x$_{f}$ given the observation y$_{f}$ (qxl) and the calibration experiment is obtained with normal priors for x$_{f}$ and for themodel parameters (.alpha., .betha.). This posterior distribution is not in the form of any known distributions, which leads to the use of a numerical integration or an approximation for the calculation of the overall expected loss. The general structure of the expected loss function is characterized in the form of a conjecture. A near-optimal design is obtained through the approximation nof the conditional covariance matrix of the joint distribution of (x$_{f}$ , y$_{f}$ $^{T}$ )$^{T}$ . Numerical results for the univariate case are given to demonstrate the conjecture and to evaluate the approximation.n.

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On loss functions for model selection in wavelet based Bayesian method

  • Park, Chun-Gun
    • Journal of the Korean Data and Information Science Society
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    • 제20권6호
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    • pp.1191-1197
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    • 2009
  • Most Bayesian approaches to model selection of wavelet analysis have drawbacks that computational cost is expensive to obtain accuracy for the fitted unknown function. To overcome the drawback, this article introduces loss functions which are criteria for level dependent threshold selection in wavelet based Bayesian methods with arbitrary size and regular design points. We demonstrate the utility of these criteria by four test functions and real data.

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ESTIMATION OF SCALE PARAMETER AND P(Y < X) FROM RAYLEIGH DISTRIBUTION

  • Kim, Chan-Soo;Chung, Youn-Shik
    • Journal of the Korean Statistical Society
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    • 제32권3호
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    • pp.289-298
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    • 2003
  • We consider the estimation problem for the scale parameter of the Rayleigh distribution using weighted balanced loss function (WBLF) which reflects both goodness of fit and precision. Under WBLF, we obtain the optimal estimator which creates a kind of balance between Bayesian and non-Bayesian estimation. We also deal with the estimation of R = P(Y < X) when Y and X are two independent but not identically distributed Rayleigh distribution under squared error loss function.

On the Bayesian Sequential Estiamtion Problem in k-Parameter Exponential Family

  • Yoon, Byoung-Chang;Kim, Jea-Joo
    • Journal of the Korean Statistical Society
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    • 제10권
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    • pp.128-139
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    • 1981
  • The Bayesian sequential estimation problem for k parameters exponential families is considered using loss related to the Fisher information. Tractable expressions for the Bayes estimator and the posterior expected loss are found, and the myopic or one-step-ahead stopping rule is defined. Sufficient conditions are given for optimality of the myopic procedure, and the myopic procedure is shown to be asymptotically optimal in all cases considered.

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후 경골 동맥에서 분지한 비 특이성 비골 골피 유리 피판에서의 관통 혈류 미세 문합을 통한 피부판의 구제 (Skin Paddle Salvage in Atypical Fibula Osteocutaneous Free Flap with Peroneal Flow through Vascular Anastomosis)

  • 김민수;유대현;이원재;탁관철
    • Archives of Reconstructive Microsurgery
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    • 제13권1호
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    • pp.24-28
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    • 2004
  • The vascularity of a skin island in fibula osteocutaneous free flap often depends on musculocutaneous perforators that find their origin in the proximal peroneal artery. But a potential drawback has been reported on the unreliability of the skin paddle. The perforating vessels to the skin paddle of the fibula osteocutaneous free flap were rarely derived from a common tibio-fibula trunk, an anterior tibial artery and a posterior tibial artery. Previous studies have emphasized total loss of the overlying skin paddle, if the expected perforating vessels are not present. We report here on our experience that the skin paddle of the fibula osteocutaneous free flap was vascularized not by a peroneal artery but a direct branch of the posterior tibial artery. There were no intraseptal nor intramuscular pedicles in the posterior crural septum which connected to the overlying skin island. Therefore, we performed microsurgical anastomoses between distal peroneal vessels of the fibula and the perforating branches of the posterior tibial vessels of the skin paddle. The anastomosed skin paddle was salvaged with a peroneal flow through vascular anastomosis and was transferred to the bone and intraoral soft tissue defects with the fibula graft. The patient had no evidence of vascular compromise in the postoperative period and showed good healing of the intraoral skin flap.

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Comparison between Posterior and Transforaminal Approaches for Lumbar Interbody Fusion

  • Park, Jae-Sung;Kim, Young-Baeg;Hong, Hyun-Jong;Hwang, Sung-Nam
    • Journal of Korean Neurosurgical Society
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    • 제37권5호
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    • pp.340-344
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    • 2005
  • Objective: Posterior lumbar interbody fusion(PLIF), the current leading method of pedicle screw fixation combined with interbody fusion via posterior route, sometimes requires too much destruction of the facet joint than expected especially for the patient with a narrow spine. On the other hand, tranforaminal lumbar interbody fusion(TLIF) technique provides potential advantages over PLIF and can be chosen as a better surgical alternative to more traditional fusion methods in certain surgical conditions. Methods: From October 1999, 99 PLIF and 29 TLIF procedures were done for the patients with spinal stenosis and instability. Radiological data including the interpedicular distance and the size of the pedicles as well as the clinical parameters were collected retrospectively. The degree of resection of the inferior articular process was compared with the interpedicular distance in each patient who received PLIF. Results: No significant differences were found between PLIF and TLIF regarding the operation time, blood loss, duration of hospital stay, or short term postoperative clinical result. There were no complication with TLIF, but PLIF resulted in 9(9.1%) complications. During PLIF procedure, all patients(n=24) except one with the interpedicular distance shorter than 27mm required near complete or complete resection of the inferior articular processes, whereas only 6(31.5%) of 19 patients with the interpedicular distances longer than 30mm required the similar extent of resection. Conclusion: TLIF is better than PLIF in terms of the complication rate. The patient who had narrow interpedicular distance(<27mm) might be better candidate for TLIF.

좁은 치조제를 가진 하악 구치부에서 지르코늄-티타늄 합금의 작은 직경 임플란트 사용 증례 (Titanium-zirconium alloy narrow-diameter implants for the rehabilitation of horizontally deficient mandibular posterior edentulous ridges)

  • 이인혜;박영범;한동후
    • 대한치과보철학회지
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    • 제55권2호
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    • pp.212-217
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    • 2017
  • 임플란트의 협설 측으로 잔존 골조직이 불충분할 경우 골증대술을 시행하지 않기 위해서는 작은 직경의 임플란트를 사용할 수 있다. 작은 직경 임플란트의 경우는 파절 저항성이 낮고, 골과 임플란트의 접촉 면적이 좁아 구치부에는 부적절한 것으로 여겨져 왔다. 최근의 연구에서는 새로운 임플란트 합금의 개발 및 표면 처리방법의 발전으로 구치부에서도 표준 직경 임플란트와 유사한 성공률이 보고되고 있다. 이 증례에서는 구치부 상실 부위 잔존골의 협설 폭이 부족한 상황에서 작은 직경 임플란트를 이용하여 심미적, 기능적으로 만족스러운 치료 결과를 보였다. 현재까지 추적 검사 기간은 4년 이상 되었고 특이할만한 합병증 없이 유지되었다. 향후 장기적인 안정성에 대한 추가적인 연구가 필요할 것으로 사료된다.