• Title/Summary/Keyword: Inverse Estimation

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Comparison of Regularization Techniques For an Inverse Radiation Boundary Analysis (역복사경계해석을 위한 다양한 조정기법 비교)

  • Kim, Ki-Wan;Baek, Seung-Wook
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1288-1293
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    • 2004
  • Inverse radiation problems are solved for estimating the boundary conditions such as temperature distribution and wall emissivity in axisymmetric absorbing, emitting and scattering medium, given the measured incident radiative heat fluxes. Various regularization methods, such as hybrid genetic algorithm, conjugate-gradient method and Newton method, were adopted to solve the inverse problem, while discussing their features in terms of estimation accuracy and computational efficiency. Additionally, we propose a new combined approach of adopting the genetic algorithm as an initial value selector, whereas using the conjugate-gradient method and Newton method to reduce their dependence on the initial value.

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Comparison of Regularization Techniques for an Inverse Radiation Boundary Analysis (역복사경계해석을 위한 다양한 조정법 비교)

  • Kim, Ki-Wan;Shin, Byeong-Seon;Kil, Jeong-Ki;Yeo, Gwon-Koo;Baek, Seung-Wook
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.29 no.8 s.239
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    • pp.903-910
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    • 2005
  • Inverse radiation problems are solved for estimating the boundary conditions such as temperature distribution and wall emissivity in axisymmetric absorbing, emitting and scattering medium, given the measured incident radiative heat fluxes. Various regularization methods, such as hybrid genetic algorithm, conjugate-gradient method and finite-difference Newton method, were adopted to solve the inverse problem, while discussing their features in terms of estimation accuracy and computational efficiency. Additionally, we propose a new combined approach that adopts the hybrid genetic algorithm as an initial value selector and uses the finite-difference Newton method as an optimization procedure.

Nonparametric Bayesian estimation on the exponentiated inverse Weibull distribution with record values

  • Seo, Jung In;Kim, Yongku
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.3
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    • pp.611-622
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    • 2014
  • The inverse Weibull distribution (IWD) is the complementary Weibull distribution and plays an important role in many application areas. In Bayesian analysis, Soland's method can be considered to avoid computational complexities. One limitation of this approach is that parameters of interest are restricted to a finite number of values. This paper introduce nonparametric Bayesian estimator in the context of record statistics values from the exponentiated inverse Weibull distribution (EIWD). In stead of Soland's conjugate piror, stick-breaking prior is considered and the corresponding Bayesian estimators under the squared error loss function (quadratic loss) and LINEX loss function are obtained and compared with other estimators. The results may be of interest especially when only record values are stored.

Parameter estimation of an extended inverse power Lomax distribution with Type I right censored data

  • Hassan, Amal S.;Nassr, Said G.
    • Communications for Statistical Applications and Methods
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    • v.28 no.2
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    • pp.99-118
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    • 2021
  • In this paper, we introduce an extended form of the inverse power Lomax model via Marshall-Olkin approach. We call it the Marshall-Olkin inverse power Lomax (MOIPL) distribution. The four- parameter MOIPL distribution is very flexible which contains some former and new models. Vital properties of the MOIPL distribution are affirmed. Maximum likelihood estimators and approximate confidence intervals are considered under Type I censored samples. Maximum likelihood estimates are evaluated according to simulation study. Bayesian estimators as well as Bayesian credible intervals under symmetric loss function are obtained via Markov chain Monte Carlo (MCMC) approach. Finally, the flexibility of the new model is analyzed by means of two real data sets. It is found that the MOIPL model provides closer fits than some other models based on the selected criteria.

Estimation of Thermal Conductivity and Diffusivity by an Inverse Analysis (역해석에 의한 열전도율 및 확산율 예측)

  • Na, Jae-Jeong;Lee, Jung-Min;Kang, Kyung-Taik
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.397-402
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    • 2012
  • The objective of this study is the estimation of the two unknown thermal conductivity and thermal diffusivity by an inverse heat conduction analysis using the Levenberg-Marguardt method. One dimensional formulation of heat conduction problem in the model was applied. Two point transient temperature of test pieces and heat flux of inflow were measured under the high enthalpy flow environment. Estimated thermal conductivity and thermal diffusivity by an inverse analysis were compared with the known values of graphite test piece. It showed the effectiveness of proposed experimental inverse analysis.

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A Study on Development Cost Attributes Analysis of NHPP Software Reliability Model Based on Rayleigh Distribution and Inverse Rayleigh Distribution (레일리 분포와 역-레일리 분포에 근거한 NHPP 소프트웨어 신뢰성 모형의 개발비용 속성 분석에 관한 연구)

  • Yang, Tae-Jin
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.12 no.6
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    • pp.554-560
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    • 2019
  • In this study, after applying the finite failure NHPP Rayleigh distribution model and NHPP Inverse Rayleigh distribution model which are widely used in the field of software reliability to the software development cost model, the attributes of development cost and optimal release time were compared and analyzed. To analyze the attributes of software development cost, software failure time data was used, parametric estimation was applied to the maximum likelihood estimation method, and nonlinear equations were calculated using the bisection method. As a result, it was confirmed that Rayleigh model is relatively superior to Inverse Rayleigh model because software development cost is relatively low and software release time is also fast. Through this study, the development cost attributes of the Rayleigh model and the Inverse Rayleigh model without the existing research examples were newly analyzed. In addition, we expect that software developers will be able to use this study as a basic guideline for exploring software reliability improvement method and development cost attributes.

A hybrid inverse method for small scale parameter estimation of FG nanobeams

  • Darabi, A.;Vosoughi, Ali R.
    • Steel and Composite Structures
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    • v.20 no.5
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    • pp.1119-1131
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    • 2016
  • As a first attempt, an inverse hybrid numerical method for small scale parameter estimation of functionally graded (FG) nanobeams using measured frequencies is presented. The governing equations are obtained with the Eringen's nonlocal elasticity assumptions and the first-order shear deformation theory (FSDT). The equations are discretized by using the differential quadrature method (DQM). The discretized equations are transferred from temporal domain to frequency domain and frequencies of the nanobeam are obtained. By applying random error to these frequencies, measured frequencies are generated. The measured frequencies are considered as input data and inversely, the small scale parameter of the beam is obtained by minimizing a defined functional. The functional is defined as root mean square error between the measured frequencies and calculated frequencies by the DQM. Then, the conjugate gradient (CG) optimization method is employed to minimize the functional and the small scale parameter is obtained. Efficiency, convergence and accuracy of the presented hybrid method for small scale parameter estimation of the beams for different applied random error, boundary conditions, length-to-thickness ratio and volume fraction coefficients are demonstrated.

New generalized inverse Weibull distribution for lifetime modeling

  • Khan, Muhammad Shuaib;King, Robert
    • Communications for Statistical Applications and Methods
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    • v.23 no.2
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    • pp.147-161
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    • 2016
  • This paper introduces the four parameter new generalized inverse Weibull distribution and investigates the potential usefulness of this model with application to reliability data from engineering studies. The new extended model has upside-down hazard rate function and provides an alternative to existing lifetime distributions. Various structural properties of the new distribution are derived that include explicit expressions for the moments, moment generating function, quantile function and the moments of order statistics. The estimation of model parameters are performed by the method of maximum likelihood and evaluate the performance of maximum likelihood estimation using simulation.

An Empirical Study on Dimension Reduction

  • Suh, Changhee;Lee, Hakbae
    • Journal of the Korean Data Analysis Society
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    • v.20 no.6
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    • pp.2733-2746
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    • 2018
  • The two inverse regression estimation methods, SIR and SAVE to estimate the central space are computationally easy and are widely used. However, SIR and SAVE may have poor performance in finite samples and need strong assumptions (linearity and/or constant covariance conditions) on predictors. The two non-parametric estimation methods, MAVE and dMAVE have much better performance for finite samples than SIR and SAVE. MAVE and dMAVE need no strong requirements on predictors or on the response variable. MAVE is focused on estimating the central mean subspace, but dMAVE is to estimate the central space. This paper explores and compares four methods to explain the dimension reduction. Each algorithm of these four methods is reviewed. Empirical study for simulated data shows that MAVE and dMAVE has relatively better performance than SIR and SAVE, regardless of not only different models but also different distributional assumptions of predictors. However, real data example with the binary response demonstrates that SAVE is better than other methods.

Inverse Estimation of Fatigue Life Parameters of Springs Based on the Bayesian Approach (베이지안 접근법을 이용한 스프링 피로 수명 파라미터의 역 추정)

  • Heo, Chan-Young;An, Da-Wn;Won, Jun-Ho;Choi, Joo-Ho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.35 no.4
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    • pp.393-400
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    • 2011
  • In this study, a procedure for the inverse estimation of the fatigue life parameters of springs which utilize the field fatigue life test data is proposed to replace real test with the FEA on fatigue life prediction. The Bayesian approach is employed, in which the posterior distributions of the parameters are determined conditional on the accumulated life data that are routinely obtained from the regular tests. In order to obtain the accurate samples from the distributions, the Markov chain Monte Carlo (MCMC) technique is employed. The distributions of the parameters are used in the FEA for predicting the fatigue life in the form of a predictive interval. The results show that the actual fatigue life data are found well within the posterior predictive distributions.