• Title/Summary/Keyword: Bayesian Design

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

  • Nam, Seung-Pyo;Bae, Jae-Min;Kwon, Kang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.32 no.4
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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.

Bayesian Model for the Classification of GPCR Agonists and Antagonists

  • Choi, In-Hee;Kim, Han-Jo;Jung, Ji-Hoon;Nam, Ky-Youb;Yoo, Sung-Eun;Kang, Nam-Sook;No, Kyoung-Tai
    • Bulletin of the Korean Chemical Society
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    • v.31 no.8
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    • pp.2163-2169
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    • 2010
  • G-protein coupled receptors (GPCRs) are involved in a wide variety of physiological processes and are known to be targets for nearly 50% of drugs. The various functions of GPCRs are affected by their cognate ligands which are mainly classified as agonists and antagonists. The purpose of this study is to develop a Bayesian classification model, that can predict a compound as either human GPCR agonist or antagonist. Total 6627 compounds experimentally determined as either GPCR agonists or antagonists covering all the classes of GPCRs were gathered to comprise the dataset. This model distinguishes GPCR agonists from GPCR antagonists by using chemical fingerprint, FCFP_6. The model revealed distinctive structural characteristics between agonistic and antagonistic compounds: in general, 1) GPCR agonists were flexible and had aliphatic amines, and 2) GPCR antagonists had planar groups and aromatic amines. This model showed very good discriminative ability in general, with pretty good discriminant statistics for the training set (accuracy: 90.1%) and a good predictive ability for the test set (accuracy: 89.2%). Also, receiver operating characteristic (ROC) plot showed the area under the curve (AUC) to be 0.957, and Matthew's Correlation Coefficient (MCC) value was 0.803. The quality of our model suggests that it could aid to classify the compounds as either GPCR agonists or antagonists, especially in the early stages of the drug discovery process.

Reliability Updates of Driven Piles Using Proof Pile Load Test Results (검증용 정재하시험 자료를 이용한 항타강관말뚝의 신뢰성 평가)

  • Park, Jae-Hyun;Kim, Dong-Wook;Kwak, Ki-Seok;Chung, Moon-Kyung;Kim, Jun-Young;Chung, Choong-Ki
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.324-337
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    • 2010
  • For the development of load and resistance factor design, reliability analysis is required to calibrate resistance factors in the framework of reliability theory. The distribution of measured-to-predicted pile resistance ratio was constructed based on only the results of load tests conducted to failure for the assessment of uncertainty regarding pile resistance and used in the conventional reliability analysis. In other words, successful pile load test (piles resisted twice their design loads without failure) results were discarded, and therefore, were not reflected in the reliability analysis. In this paper, a new systematic method based on Bayesian theory is used to update reliability index of driven steel pile piles by adding more pile load test results, even not conducted to failure, into the prior distribution of pile resistance ratio. Fifty seven static pile load tests performed to failure in Korea were compiled for the construction of prior distribution of pile resistance ratio. Reliability analyses were performed using the updated distribution of pile resistance ratio and the total load distribution using First-order Reliability Method (FORM). The challenge of this study is that the distribution updates of pile resistance ratio are possible using the load test results even not conducted to failure, and that Bayesian update are most effective when limited data are available for reliability analysis or resistance factors calibration.

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Parameter Estimation and Reliability Analysis Using Bayesian Approach for Bolted Joint and O-ring Seal of Solid Rocket Motor (고체 로켓 모터의 체결 볼트와 오링에 대한 베이지안 접근법 기반 모수 추정과 신뢰성 해석)

  • Gang, Jin Hyuk;Choi, Joo Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.11
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    • pp.1055-1064
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    • 2017
  • Since a device such as a rocket motor requires very high reliability, a reasonable reliability design process is essential. However, Korea has implemented a design method for applying a safety factor to each component. In classic reliability analysis, input variables such as mean and standard deviation, used in the limit state function, are treated as deterministic values. Because the mean and standard deviation are determined by a small amount of data, this approach could lead to inaccurate results. In this study, reliability analysis is performed for bolted joints and o-ring seals, and the Bayesian approach is used to statistically estimate the input variables. The estimated variables and failure probability, calculated by the reliability analysis, are derived in the form of probability distributions.

Accuracy of Brownian Motion Approximation in Group Sequential Methods

  • Euy Hoon Suh
    • Communications for Statistical Applications and Methods
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    • v.6 no.1
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    • pp.207-220
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    • 1999
  • In this paper, some of the issue about a group sequential method are considered in the Bayesian context. The continuous time optimal stopping boundary can be used to approximate the optimal stopping boundary for group sequential designs. The exact stopping boundary for group sequential design is obtained by using the backward induction method and is compared with the continuous optimal stopping boundary and the corrected continuous stopping boundary.

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Ultrasonic Signal Analysis with DSP for the Pattern Recognition of Welding Flaws

  • Kim, Jae-Yeol;Cho, Gyu-Jae;Kim, Chang-Hyun
    • International Journal of Precision Engineering and Manufacturing
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    • v.1 no.1
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    • pp.106-110
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    • 2000
  • The researches classifying the artificial flaws in welding parts are performed using the pattern recognition technology. For this purpose the signal pattern recognition package including user defined function is developed and the total procedure is made up the digital signal processing, feature extraction, feature selection, classfier design. Specially it is composed with and discussed using the ststistical classfier such as the linear discriminant function classfier, the empirical Bayesian classfier.

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PDC Intelligent control-based theory for structure system dynamics

  • Chen, Tim;Lohnash, Megan;Owens, Emmanuel;Chen, C.Y.J.
    • Smart Structures and Systems
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    • v.25 no.4
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    • pp.401-408
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    • 2020
  • This paper deals with the problem of global stabilization for a class of nonlinear control systems. An effective approach is proposed for controlling the system interaction of structures through a combination of parallel distributed compensation (PDC) intelligent controllers and fuzzy observers. An efficient approximate inference algorithm using expectation propagation and a Bayesian additive model is developed which allows us to predict the total number of control systems, thereby contributing to a more adaptive trajectory for the closed-loop system and that of its corresponding model. The closed-loop fuzzy system can be made as close as desired, so that the behavior of the closed-loop system can be rigorously predicted by establishing that of the closed-loop fuzzy system.

A Design of the Small File Grouping System Based on Naive Bayesian Classifier Model (나이브 베이지안 분류기 모델 기반의 소용량 파일 그룹화 시스템 설계)

  • Kim, Min-Jae;Kim, Kyung-Tae;Youn, Hee-Young
    • Proceedings of the Korean Society of Computer Information Conference
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    • 2014.07a
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    • pp.221-222
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    • 2014
  • 빠른 웹의 성장으로 대용량 데이터를 효과적으로 처리할 수 있는 플랫폼 기술에 대한 관심이 높아지고 있다. 특히, HDFS는 이상적인 분산 파일 시스템으로 각광받고 있으며 대용량 파일의 처리를 목적으로 개발되었다. 하지만, 실제 파일들의 집합에서 소용량 파일이 차지하는 비중은 높은 편이다. 많은 수의 소용량 파일은 HDFS 성능 감소에 치명적인 원인이 된다. 많은 수의 소용량 파일들이 HDFS에 저장된다면 NameNode의 메모리 소비량이 증가하게 되며 많은 수의 소용량 파일은 많은 수의 DataNode와 NameNode를 요구하므로 상대적으로 처리시간이 많이 소모된다. 따라서 본 논문에서는 HDFS에서 소용량 파일의 저장과 액세스 효율성을 향상시키기 위하여 나이브 베이지안 분류기 알고리즘을 적용한 파일 그룹화 시스템을 설계하였다.

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A new statistical approach for joint shear strength determination of RC beam-column connections subjected to lateral earthquake loading

  • Kim, Jaehong;LaFavet, James M.;Song, Junho
    • Structural Engineering and Mechanics
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    • v.27 no.4
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    • pp.439-456
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    • 2007
  • Reinforced concrete (RC) joint shear strength models are constructed using an experimental database in conjunction with a Bayesian parameter estimation method. The experimental database consists of RC beam-column connection test subassemblies that maintained proper confinement within the joint panel. All included test subassemblies were subjected to quasi-static cyclic lateral loading and eventually experienced joint shear failure (either in conjunction with or without yielding of beam reinforcement); subassemblies with out-of-plane members and/or eccentricity between the beam(s) and the column are not included in this study. Three types of joint shear strength models are developed. The first model considers all possible influence parameters on joint shear strength. The second model contains those parameters left after a step-wise process that systematically identifies and removes the least important parameters affecting RC joint shear strength. The third model simplifies the second model for convenient application in practical design. All three models are unbiased and show similar levels of scatter. Finally, the improved performance of the simplified model for design is identified by comparison with the current ACI 352R-02 RC joint shear strength model.

Robust wireless sensor network configuration design for structural health monitoring with optimal information-energy tradeoff

  • Xiao-Han Hao;Sin-Chi Kuok;Ka-Veng Yuen
    • Smart Structures and Systems
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    • v.33 no.6
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    • pp.465-482
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    • 2024
  • In this paper, a robust wireless sensor network configuration design method is proposed to develop the optimal configuration under the consideration of sensor failure and energy consumption. A malfunctioned sensor in a wireless sensor network may lead to data transmission failure of the entire sensing cluster, inducing severe deterioration in system identification performance. The proposed method determines a wireless sensor network configuration that is robust against sensor failure. By utilizing Bayesian inference, we introduce a robust indicator to evaluate the impact on estimation accuracy of sensor configurations with various malfunctioned sensors. Moreover, a network formation strategy is proposed to optimize the energy efficiency of the wireless sensor network configuration. Therefore, the resultant robust wireless sensor network configuration can operate with the minimum energy consumption while the measurement information of the sensor network with malfunctioned sensors can be guaranteed. The proposed method is illustrated by designing the robust wireless sensor network configurations of a truss model and a bridge model.