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Article
Publication date: 17 July 2009

Emmanuel Blanchard, Adrian Sandu and Corina Sandu

The purpose of this paper is to propose a new computational approach for parameter estimation in the Bayesian framework. A posteriori probability density functions are obtained…

Abstract

Purpose

The purpose of this paper is to propose a new computational approach for parameter estimation in the Bayesian framework. A posteriori probability density functions are obtained using the polynomial chaos theory for propagating uncertainties through system dynamics. The new method has the advantage of being able to deal with large parametric uncertainties, non‐Gaussian probability densities and nonlinear dynamics.

Design/methodology/approach

The maximum likelihood estimates are obtained by minimizing a cost function derived from the Bayesian theorem. Direct stochastic collocation is used as a less computationally expensive alternative to the traditional Galerkin approach to propagate the uncertainties through the system in the polynomial chaos framework.

Findings

The new approach is explained and is applied to very simple mechanical systems in order to illustrate how the Bayesian cost function can be affected by the noise level in the measurements, by undersampling, non‐identifiablily of the system, non‐observability and by excitation signals that are not rich enough. When the system is non‐identifiable and an a priori knowledge of the parameter uncertainties is available, regularization techniques can still yield most likely values among the possible combinations of uncertain parameters resulting in the same time responses than the ones observed.

Originality/value

The polynomial chaos method has been shown to be considerably more efficient than Monte Carlo in the simulation of systems with a small number of uncertain parameters. This is believed to be the first time the polynomial chaos theory has been applied to Bayesian estimation.

Details

Engineering Computations, vol. 26 no. 5
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 18 January 2016

Huajun Liu, Cailing Wang and Jingyu Yang

– This paper aims to present a novel scheme of multiple vanishing points (VPs) estimation and corresponding lanes identification.

Abstract

Purpose

This paper aims to present a novel scheme of multiple vanishing points (VPs) estimation and corresponding lanes identification.

Design/methodology/approach

The scheme proposed here includes two main stages: VPs estimation and lane identification. VPs estimation based on vanishing direction hypothesis and Bayesian posterior probability estimation in the image Hough space is a foremost contribution, and then VPs are estimated through an optimal objective function. In lane identification stage, the selected linear samples supervised by estimated VPs are clustered based on the gradient direction of linear features to separate lanes, and finally all the lanes are identified through an identification function.

Findings

The scheme and algorithms are tested on real data sets collected from an intelligent vehicle. It is more efficient and more accurate than recent similar methods for structured road, and especially multiple VPs identification and estimation of branch road can be achieved and lanes of branch road can be identified for complex scenarios based on Bayesian posterior probability verification framework. Experimental results demonstrate VPs, and lanes are practical for challenging structured and semi-structured complex road scenarios.

Originality/value

A Bayesian posterior probability verification framework is proposed to estimate multiple VPs and corresponding lanes for road scene understanding of structured or semi-structured road monocular images on intelligent vehicles.

Details

Industrial Robot: An International Journal, vol. 43 no. 1
Type: Research Article
ISSN: 0143-991X

Keywords

Article
Publication date: 1 January 2008

Peng Liu, Elia El‐Darzi, Lei Lei, Christos Vasilakis, Panagiotis Chountas and Wei Huang

Purpose – Data preparation plays an important role in data mining as most real life data sets contained missing data. This paper aims to investigate different treatment methods…

Abstract

Purpose – Data preparation plays an important role in data mining as most real life data sets contained missing data. This paper aims to investigate different treatment methods for missing data. Design/methodology/approach – This paper introduces, analyses and compares well‐established treatment methods for missing data and proposes new methods based on naïve Bayesian classifier. These methods have been implemented and compared using a real life geriatric hospital dataset. Findings – In the case where a large proportion of the data is missing and many attributes have missing data, treatment methods based on naïve Bayesian classifier perform very well. Originality/value – This paper proposes an effective missing data treatment method and offers a viable approach to predict inpatient length of stay from a data set with many missing values.

Details

Journal of Enterprise Information Management, vol. 21 no. 1
Type: Research Article
ISSN: 1741-0398

Keywords

Article
Publication date: 29 November 2019

A. George Assaf and Mike G. Tsionas

This paper aims to present several Bayesian specification tests for both in- and out-of-sample situations.

Abstract

Purpose

This paper aims to present several Bayesian specification tests for both in- and out-of-sample situations.

Design/methodology/approach

The authors focus on the Bayesian equivalents of the frequentist approach for testing heteroskedasticity, autocorrelation and functional form specification. For out-of-sample diagnostics, the authors consider several tests to evaluate the predictive ability of the model.

Findings

The authors demonstrate the performance of these tests using an application on the relationship between price and occupancy rate from the hotel industry. For purposes of comparison, the authors also provide evidence from traditional frequentist tests.

Research limitations/implications

There certainly exist other issues and diagnostic tests that are not covered in this paper. The issues that are addressed, however, are critically important and can be applied to most modeling situations.

Originality/value

With the increased use of the Bayesian approach in various modeling contexts, this paper serves as an important guide for diagnostic testing in Bayesian analysis. Diagnostic analysis is essential and should always accompany the estimation of regression models.

Details

International Journal of Contemporary Hospitality Management, vol. 32 no. 4
Type: Research Article
ISSN: 0959-6119

Keywords

Article
Publication date: 1 January 1986

ROGER N. CONWAY and RON C. MITTELHAMMER

In the last two decades there has been considerable progress made in the development of alternative estimation techniques to ordinary least squares (OLS) regression. The search…

Abstract

In the last two decades there has been considerable progress made in the development of alternative estimation techniques to ordinary least squares (OLS) regression. The search for alternative estimators has no doubt been motivated by the observance of erratic OLS estimator behavior in cases where there are too few observations, multicollinearity problems, or simply “information‐poor” data sets. Imprecise and unreliable OLS coefficient estimates have been the result.

Details

Studies in Economics and Finance, vol. 10 no. 1
Type: Research Article
ISSN: 1086-7376

Article
Publication date: 11 September 2017

Arvind Shrivastava, Nitin Kumar and Purnendu Kumar

Decisions pertaining to working capital management have pivotal role for firms’ short-term financial decisions. The purpose of this paper is to examine impact of working capital…

1640

Abstract

Purpose

Decisions pertaining to working capital management have pivotal role for firms’ short-term financial decisions. The purpose of this paper is to examine impact of working capital on profitability for Indian corporate entities.

Design/methodology/approach

Both classical panel analysis and Bayesian techniques have been employed that provides opportunity not only to perform comparative analysis but also allows flexibility in prior distribution assumptions.

Findings

It is found that longer cash conversion period has detrimental influence on profitability. Financial soundness indicators are playing significant role in determining firm profitability. Larger firms seem to be more profitable and significant as per Bayesian approach. Bayesian approach has led to considerable gain in estimation fit.

Practical implications

Observing the highly skewed distribution of dependent variable, Multivariate Student t-distribution has been considered along with normal distribution to model stochastic term. Accordingly, Bayesian methodology is applied.

Originality/value

Analysis of working capital for firms has been performed in Indian context. Application of Bayesian methodology is performed on balanced panel spanning from 2003 to 2012. As per author’s knowledge, this is the first study which applies Bayesian approach employing panel data for the analysis of working capital management for Indian firms.

Details

Journal of Economic Studies, vol. 44 no. 4
Type: Research Article
ISSN: 0144-3585

Keywords

Article
Publication date: 1 May 1990

B.D. Bunday and I.D. Al‐Ayoubi

The contents and function of a computer package to fit reliability models for computer software are outlined. Parameters in the models are, in the first place, estimated by…

Abstract

The contents and function of a computer package to fit reliability models for computer software are outlined. Parameters in the models are, in the first place, estimated by maximum likelihood estimation procedures. Bayesian estimation methods are also used and are shown to give estimates with a smaller variance than their MLE counterparts. An example of the application to a particular set of failure times is given.

Details

International Journal of Quality & Reliability Management, vol. 7 no. 5
Type: Research Article
ISSN: 0265-671X

Keywords

Article
Publication date: 6 September 2011

Manoj Kumar Rastogi and Yogesh Mani Tripathi

Burr distribution has been proved to be a useful failure model. It can assume different shapes which allow it to be a good fit for various lifetimes data. Hybrid censoring is an…

506

Abstract

Purpose

Burr distribution has been proved to be a useful failure model. It can assume different shapes which allow it to be a good fit for various lifetimes data. Hybrid censoring is an important way of generating lifetimes data. The purpose of this paper is to estimate an unknown parameter of the Burr type XII distribution when data are hybrid censored.

Design/methodology/approach

The problem is dealt with through both the classical and Bayesian point of view. Specifically, the methods of estimation used to tackle the problem are maximum likelihood estimation method and Bayesian method. Empirical Bayesian approach is also considered. The performance of all estimates is compared through their mean square error values. The paper employs Monte Carlo simulation to evaluate the mean square error values of all estimates.

Findings

The key findings of the paper are that the Bayesian estimates are superior to the maximum likelihood estimates (MLE).

Practical implications

This work has practical importance. Indeed, the proposed methods are applied to real life data.

Originality/value

The paper is original and is quite applicable in lifetimes data analysis.

Details

International Journal of Quality & Reliability Management, vol. 28 no. 8
Type: Research Article
ISSN: 0265-671X

Keywords

Article
Publication date: 22 June 2020

Siju K C, Mahesh Kumar and Michael Beer

This article presents the multi-state stress-strength reliability computation of a component having three states namely, working, deteriorating and failed state.

Abstract

Purpose

This article presents the multi-state stress-strength reliability computation of a component having three states namely, working, deteriorating and failed state.

Design/methodology/approach

The probabilistic approach is used to obtain the reliability expression by considering the difference between the values of stress and strength of a component, say, for example, the stress (load) and strength of a power generating unit is in terms of megawatt. The range of values taken by the difference variable determines the various states of the component. The method of maximum likelihood and Bayesian estimation is used to obtain the estimators of the parameters and system reliability.

Findings

The maximum likelihood and Bayesian estimates of the reliability approach the actual reliability for increasing sample size.

Originality/value

Obtained a new expression for the multi-state stress-strength reliability of a component and the findings are positively supported by presenting the general trend of estimated values of reliability approaching the actual value of reliability.

Details

International Journal of Quality & Reliability Management, vol. 38 no. 2
Type: Research Article
ISSN: 0265-671X

Keywords

Article
Publication date: 5 April 2021

Byron J. Idrovo-Aguirre and Javier E. Contreras-Reyes

This paper combines the objective information of six mixed-frequency partial-activity indicators with assumptions or beliefs (called priors) regarding the distribution of the…

Abstract

Purpose

This paper combines the objective information of six mixed-frequency partial-activity indicators with assumptions or beliefs (called priors) regarding the distribution of the parameters that approximate the state of the construction activity cycle. Thus, this paper uses Bayesian inference with Gibbs simulations and the Kalman filter to estimate the parameters of the state-space model, used to design the Imacon.

Design/methodology/approach

Unlike other economic sectors of similar importance in aggregate gross domestic product, such as mining and industry, the construction sector lacked a short-term measure that helps to identify its most recent performance.

Findings

Indeed, because these priors are susceptible to changes, they provide flexibility to the original Imacon model, allowing for the assessment of risk scenarios and adaption to the greater relative volatility that characterizes the sector's activity.

Originality/value

The classic maximum likelihood method of estimating the monthly construction activity index (Imacon) is rigid to the incorporation of new measures of uncertainty, expectations or different volatility (risks) levels in the state of construction activity. In this context, this paper uses Bayesian inference with 10,000 Gibbs simulations and the Kalman filter to estimate the parameters of the state-space model, used to design the Imacon, inspired by the original works of Mariano and Murasawa (2003) and Kim and Nelson (1998). Thus, this paper consists of a natural extension of the classic method used by Tejada (2006) in the estimation of the old Imacon.

Details

Journal of Economic Studies, vol. 49 no. 3
Type: Research Article
ISSN: 0144-3585

Keywords

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