1,349 results
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2. Estimation of stress–strength reliability for inverse exponentiated distributions with application
- Author
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Kumari, Rani, Lodhi, Chandrakant, Tripathi, Yogesh Mani, and Sinha, Rajesh Kumar
- Published
- 2023
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- View/download PDF
3. Multicomponent stress-strength reliability estimation based on unit generalized Rayleigh distribution
- Author
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Jha, Mayank Kumar, Tripathi, Yogesh Mani, and Dey, Sanku
- Published
- 2021
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4. Measurement and Evaluation of the Development Level of Health and Wellness Tourism from the Perspective of High-Quality Development.
- Author
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Pan, Huali, Mi, Huanhuan, Chen, Yanhua, Chen, Ziyan, and Zhou, Weizhong
- Abstract
In recent years, with the dramatic surge in the demand for health and elderly care services, the emergence of the health dividend has presented good development opportunities for health and wellness tourism. However, as a sector of the economy, health and wellness tourism still faces numerous challenges in achieving high-quality development. Therefore, this paper focuses on 31 provinces in China and constructs a multidimensional evaluation index system for the high-quality development of health and wellness tourism. The global entropy-weighted TOPSIS method and cluster analysis are used to conduct in-depth measurements, regional comparisons, and classification evaluations of the high-quality development of health and wellness tourism in each province. The research results indicate that: (1) From a quality perspective, the level of health and wellness tourism development in 11 provinces in China has exceeded the national average, while the remaining 20 provinces are below the national average. (2) From a regional perspective, the current level of high-quality development in health and wellness tourism decreases sequentially from the eastern to the central to the western regions, with significant regional differences. (3) Overall, the development in the 31 provinces can be categorized into five types: the High-Quality Benchmark Type, the High-Quality Stable Type, the High-Quality Progressive Type, the General-Quality Potential Type, and the General-Quality Lagging Type. (4) From a single-dimension analysis perspective, there are significant differences in the rankings of each province across different dimensions. Finally, this paper enriches and expands the theoretical foundation on the high-quality development of health and wellness tourism; on the other hand, it puts forward targeted countermeasures and suggestions to help promote the comprehensive enhancement of health and wellness tourism. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Three-Dimensional Image Visualization under Photon-Starved Conditions Using N Observations and Statistical Estimation.
- Author
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Kim, Hyun-Woo, Lee, Min-Chul, and Cho, Myungjin
- Subjects
THREE-dimensional imaging ,MAXIMUM likelihood statistics ,PHOTON counting ,POISSON distribution ,POISSON processes ,STOCHASTIC processes ,SIGNAL-to-noise ratio - Abstract
In this paper, we propose a method for the three-dimensional (3D) image visualization of objects under photon-starved conditions using multiple observations and statistical estimation. To visualize 3D objects under these conditions, photon counting integral imaging was used, which can extract photons from 3D objects using the Poisson random process. However, this process may not reconstruct 3D images under severely photon-starved conditions due to a lack of photons. Therefore, to solve this problem, in this paper, we propose N-observation photon-counting integral imaging with statistical estimation. Since photons are extracted randomly using the Poisson distribution, increasing the samples of photons can improve the accuracy of photon extraction. In addition, by using a statistical estimation method, such as maximum likelihood estimation, 3D images can be reconstructed. To prove our proposed method, we implemented the optical experiment and calculated its performance metrics, which included the peak signal-to-noise ratio (PSNR), structural similarity (SSIM), peak-to-correlation energy (PCE), and the peak sidelobe ratio (PSR). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. A New Extension of the Exponentiated Weibull–Poisson Family Using the Gamma-Exponentiated Weibull Distribution: Development and Applications.
- Author
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Chaisee, Kuntalee, Khamkong, Manad, and Paksaranuwat, Pawat
- Subjects
DISTRIBUTION (Probability theory) ,WEIBULL distribution ,PARAMETER estimation ,HAZARD function (Statistics) ,SURVIVAL rate - Abstract
This study proposes a new five-parameter distribution called the gamma-exponentiated Weibull–Poisson (GEWP) distribution. As an extension of the exponentiated Weibull–Poisson family, the GEWP distribution offers a more flexible tool for analyzing a wider variety of data due to its theoretically and practically advantageous properties. It encompasses established distributions like the exponential, Weibull, and exponentiated Weibull. The development of the GEWP distribution proposed in this paper is obtained by combining the gamma–exponentiated Weibull (GEW) and the exponentiated Weibull–Poisson (EWP) distributions. Therefore, it serves as an extension of both the GEW and EWP distributions. This makes the GEWP a viable alternative for describing the variability of occurrences, enabling analysis in situations where GEW and EWP may be limited. This paper analyzes the probability distribution functions and provides the survival and hazard rate functions, the sub-models, the moments, the quantiles, and the maximum likelihood estimation of the GEWP distribution. Then, the numerical experiments for the parameter estimation of GEWP distribution for some finite sample sizes are presented. Finally, the comparative study of GEWP distribution and its sub-models is investigated via the goodness of fit test with real datasets to illustrate its potentiality. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. Estimation of Parameters of Misclassified Size Biased Uniform Poisson Distribution and Its Application.
- Author
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Trivedi, B. S., Barot, D. R., and Patel, M. N.
- Abstract
Statistical data analysis is of great interest in every field of management, business, engineering, medicine, etc. At the time of classification and analysis, errors may arise, like a classification of observation in the other class instead of the actual class. All fields of science and economics have substantial problems due to misclassification errors in the observed data. Due to a misclassification error in the data, the sampling process may not suggest an appropriate probability distribution, and in that case, inference is impaired. When these types of errors are identified in variables, it is expected to consider the problem's solution regarding classification errors. This paper presents the situation where specific counts are reported erroneously as belonging to other counts in the context of size biased Uniform Poisson distribution, the so-called misclassified size biased Uniform Poisson distribution. Further, we have estimated the parameters of misclassified size biased Uniform Poisson distribution by applying the method of moments, maximum likelihood method, and approximate Bayes estimation method. A simulation study is carried out to assess the performance of estimation methods. A real dataset is discussed to demonstrate the suitability and applicability of the proposed distribution in the modeling count dataset. A Monte Carlo simulation study is presented to compare the estimators. The simulation results show that the ML estimates perform better than their corresponding moment estimates and approximate Bayes estimates. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. Estimation of multicomponent stress–strength reliability for exponentiated Gumbel distribution.
- Author
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Chacko, Manoj and Elizabeth Koshy, Ashly
- Subjects
BAYES' estimation ,MARKOV chain Monte Carlo ,MAXIMUM likelihood statistics ,ERROR functions - Abstract
In this paper, the stress–strength reliability $ R_{s,k} $ R s , k of a multicomponent s-out-of-k system for exponentiated Gumbel distribution is considered. An s-out-of-k system means a system with total k components and the system can survive only when atleast s of the total components function properly. The ability of the system to overcome the experiencing stress with its strength is termed as its stress–strengh reliability. The maximum likelihood estimator and Bayes estimator for $ R_{s,k} $ R s , k are obtained. The Bayes estimators are obtained using Markov chain Monte Carlo(MCMC) method under both symmetric and asymmetric loss functions. The loss functions we considered are squared error loss function, LINEX loss function and entropy loss function. The asymptotic, bootstrap and highest posterior density(HPD) confidence intervals for $ R_{s,k} $ R s , k are also obtained. A simulation study is conducted for evaluating the efficiency of the estimators derived in this paper. Real data sets are also considered for illustration. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. EJAZ DISTRIBUTION A NEW TWO PARAMETRIC DISTRIBUTION FOR MODELLING DATA.
- Author
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AHMAD, AIJAZ, LONE, M. A., and RATHER, AAFAQ. A.
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PROBABILITY theory ,PROBABILITY density function ,RELIABILITY in engineering - Abstract
This paper introduces a novel probability distribution known as the Ejaz distribution (ED), which is characterized by two parameters. The study offers a comprehensive analysis of this distribution, including an examination of key properties such as moments, moment-generating functions, order statistics, and reliability functions. Additionally, the paper explores the graphical representation of essential functions like the probability density function, cumulative distribution function, and hazard rate function, enhancing our visual understanding of their behavior. The distribution's parameters are estimated using the widely accepted method of maximum likelihood estimation. Through real-world examples, the paper highlights the practical applicability of the Ejaz distribution, demonstrating its performance and relevance in diverse scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2024
10. On Modeling Bivariate Left Censored Data Using Reversed Hazard Rates
- Author
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Vasudevan, Durga and Asha, G.
- Published
- 2023
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11. Properties, estimation, and applications of the extended log-logistic distribution.
- Author
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Kariuki, Veronica, Wanjoya, Anthony, Ngesa, Oscar, Alharthi, Amirah Saeed, Aljohani, Hassan M., and Afify, Ahmed Z.
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ESTIMATION theory ,MAXIMUM likelihood statistics ,ORDER statistics ,DATA modeling ,SIMPLICITY - Abstract
This paper presents the exponentiated alpha-power log-logistic (EAPLL) distribution, which extends the log-logistic distribution. The EAPLL distribution emphasizes its suitability for survival data modeling by providing analytical simplicity and accommodating both monotone and non-monotone failure rates. We derive some of its mathematical properties and test eight estimation methods using an extensive simulation study. To determine the best estimation approach, we rank mean estimates, mean square errors, and average absolute biases on a partial and overall ranking. Furthermore, we use the EAPLL distribution to examine three real-life survival data sets, demonstrating its superior performance over competing log-logistic distributions. This study adds vital insights to survival analysis methodology and provides a solid framework for modeling various survival data scenarios. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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12. Robust maximum correntropy criterion based square-root rotating lattice Kalman filter.
- Author
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Liu, Sanshan, Wang, Shiyuan, Lin, Dongyuan, Zheng, Yunfei, Guo, Zhongyuan, and Kuang, Zhijian
- Abstract
Lattice Kalman filter (LKF) is a nonlinear Kalman filter that utilizes a deterministic sampling method with the advantages of optional sampling points and a flexible balance between computational burden and estimation accuracy. However, the fixed angle of sampling points in LKF can limit the optimality of the selected points. To this end, this paper proposes a novel maximum correntropy square-root rotating lattice Kalman filter (MCSRLKF) to improve the performance of LKF by adjusting the angle of sampling points. In MCSRLKF, a rotation matrix is first constructed to enhance the estimation accuracy of LKF and the optimal rotation angle of sampling points is selected to generate rotating lattice Kalman filter (RLKF). Then, the square-root RLKF (SRLKF) is proposed to enhance the stability and estimation accuracy of RLKF. Due to the utilization of the minimum mean square error criterion in SRLKF, there is a potential for significant performance degradation in non-Gaussian noises. Thus, to enhance the robustness against non-Gaussian noises, the maximum correntropy criterion is applied to SRLKF, generating MCSRLKF. Moreover, the Cramér-Rao lower bound (CRLB) serves as an indicator for assessing the performance of MCSRLKF. Finally, simulations on the nonlinear function model and reentry vehicle tracking model are used to demonstrate that MCSRLKF exhibits excellent filtering accuracy and robustness when dealing with non-Gaussian noises. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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13. Chen-Burr XII Model as a Competing Risks Model with Applications to Real-Life Data Sets.
- Author
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Kalantan, Zakiah I., Binhimd, Sulafah M. S., Salem, Heba N., AL-Dayian, Gannat R., EL-Helbawy, Abeer A., and Elaal, Mervat K. Abd
- Subjects
PROBABILITY density function ,MAXIMUM likelihood statistics ,HAZARD function (Statistics) ,COMPETING risks ,PARAMETER estimation - Abstract
In this paper Chen-Burr XII distribution is constructed and graphical description of the probability density function, hazard rate and reversed hazard rate functions of the proposed model is obtained. Also, some statistical characteristics of the Chen-Burr XII distribution are discussed and some new models as sub-models from the Chen-Burr XII distribution are introduced. Moreover, maximum likelihood estimation of the parameters, reliability, hazard rate and reversed hazard rate functions of the Chen-Burr XII distribution are considered. Also, the asymptotic confidence intervals of the distribution parameters, reliability, hazard rate and reversed hazard rate functions are presented. Finally, three real life data sets are applied to prove how the Chen-Burr XII distribution can be applied in real life and to confirm its superiority over some existing distributions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. A New Generalization of the Uniform Distribution: Properties and Applications to Lifetime Data.
- Author
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González-Hernández, Isidro Jesús, Méndez-González, Luis Carlos, Granillo-Macías, Rafael, Rodríguez-Muñoz, José Luis, and Pacheco-Cedeño, José Sergio
- Subjects
PROBABILITY density function ,MAXIMUM likelihood statistics ,RELIABILITY in engineering ,RANDOM variables ,DISTRIBUTION (Probability theory) - Abstract
In this paper, we generalize two new statistical distributions, to improve the ability to model failure rates with non-monotonic, monotonic, and mainly bathtub curve behaviors. We call these distributions Generalized Powered Uniform Distribution and MOE-Powered Uniform. The proposed distributions' approach is based on incorporating a parameter k in the power of the values of the random variables, which is associated with the Probability Density Function and includes an operator called the Powered Mean. Various statistical and mathematical features focused on reliability analysis are presented and discussed, to make the models attractive to reliability engineering or medicine specialists. We employed the Maximum Likelihood Estimator method to estimate the model parameters and we analyzed its performance through a Monte Carlo simulation study. To demonstrate the flexibility of the proposed approach, a comparative analysis was carried out on four case studies with the proposed MOE-Powered Uniform distribution, which can model failure times as a bathtub curve. The results showed that this new model is more flexible and useful for performing reliability analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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15. Unit compound Rayleigh model: Statistical characteristics, estimation and application.
- Author
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Qin Gong, Laijun Luo, and Haiping Ren
- Subjects
MONTE Carlo method ,UNCERTAINTY (Information theory) ,DISTRIBUTION (Probability theory) ,PROBABILITY theory ,MOMENTS method (Statistics) ,RAYLEIGH model - Abstract
In this paper, we proposed a novel probability distribution model known as the unit compound Rayleigh distribution, which possesses the distinctive characteristic of defining the range within the bounded interval (0,1). Through an in-depth investigation of this distribution, we analyzed various statistical and structural characteristics including reliability function, risk function, quantile function, moment analysis, order statistics, and entropy measurement. To estimate the unknown parameters of our proposed distribution model, we employed maximum likelihood (ML) estimation and Bayesian estimation. Furthermore, we derived several entropy measures based on ML estimation under the unit compound Rayleigh distribution. To comprehensively evaluate the performance of these entropies, we employed the Monte Carlo simulation method to calculate the average entropy estimate, average entropy bias, corresponding mean square error, and mean relative estimate for assessing the performance of various entropies within the unit compound Rayleigh distribution model. Finally, in order to validate its potential for practical applications, two sets of real data were selected for empirical analysis where fitting and parameter estimation were conducted to demonstrate the advantages of utilizing the unit compound Rayleigh distribution in describing and predicting actual data. This study not only introduces a new probability theory and statistics framework by proposing a novel distribution model but also provides researchers and practitioners in related fields with a powerful analytical tool. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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16. Testing Correlation in a Three-Level Model
- Author
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Szczepańska-Álvarez, Anna, Álvarez, Adolfo, Szwengiel, Artur, and von Rosen, Dietrich
- Published
- 2024
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17. Model averaging estimation for nonparametric varying-coefficient models with multiplicative heteroscedasticity
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Sun, Xianwen and Zhang, Lixin
- Published
- 2024
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18. On the Interpolating Family of Distributions.
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Nadarajah, Saralees and Okorie, Idika E.
- Subjects
MAXIMUM likelihood statistics ,BETA functions ,MAXIMUM entropy method - Abstract
A recent paper introduced the interpolating family (IF) of distributions, and they also derived various mathematical properties of the family. Some of the most important properties discussed were the integer order moments of the IF distributions. The moments were expressed as an integral (which were not evaluated) or as finite sums of the beta function. In this paper, more general expressions for moments of any integer order or any real order are derived. Apart from being more general, our expressions converge for a wider range of parameter values. The expressions for entropies are also derived, the maximum likelihood estimation is considered and the finite sample performance of maximum likelihood estimates is investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
19. Enhanced positronium lifetime imaging through two-component reconstruction in time-of-flight positron emission tomography.
- Author
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Chen, Zhuo, Kao, Chien-Min, Huang, Hsiun-Hsiung, An, Lingling, Stepien, Ewa L., and Shopa, Roman
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IMAGE reconstruction ,MAXIMUM likelihood statistics ,POSITRONIUM ,POSITRONS ,PHYSICS ,RADIOACTIVE tracers - Abstract
Positronium lifetime imaging (PLI) is a newly demonstrated technique possible with time-of-flight (TOF) positron emission tomography (PET), capable of producing an image reflecting the lifetime of the positron, more precisely ortho-positronium (o-Ps), before annihilation, in addition to the traditional uptake image of the PET tracer. Due to the limited time resolution of TOF- PET systems and the added complexities in physics and statistics, lifetime image reconstruction presents a challenge. Recently, we described a maximum- likelihood approach for PLI by considering only o-Ps. In real-world scenarios, other populations of positrons that exhibit different lifetimes also exist. This paper introduces a novel two-component model aimed at enhancing the accuracy of o-Ps lifetime images. Through simulation studies, we compare this new model with the existing single-component model and demonstrate its superior performance in accurately capturing complex lifetime distributions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
20. Dichotomous Proportional Hazard Regression Model: A Case Study on Students' Dropout.
- Author
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Martínez-Flórez, Guillermo, Tovar-Falón, Roger, and Barrera-Causil, Carlos
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PROPORTIONAL hazards models ,CUMULATIVE distribution function ,MAXIMUM likelihood statistics ,STATISTICAL models ,SCHOOL dropouts - Abstract
In problems involving binary classification, researchers often encounter data suitable for modeling dichotomous responses. These scenarios include medical diagnostics, where outcomes are classified as "disease" or "no disease", and credit scoring in finance, determining whether a loan applicant is "high risk" or "low risk". Dichotomous response models are also useful in many other areas for estimating binary responses. The logistic regression model is one option for modeling dichotomous responses; however, other statistical models may be required to improve the quality of fits. In this paper, a new regression model is proposed for cases where the response variable is dichotomous. This novel, non-linear model is derived from the cumulative distribution function of the proportional hazard distribution, and is suitable for modeling binary responses. Statistical inference is performed using a classical approach with the maximum likelihood method for the proposed model. Additionally, it is demonstrated that the introduced model has a non-singular information matrix. The results of a simulation study, along with an application to student dropout data, show the great potential of the proposed model in practical and everyday situations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Estimating mixed-effects state-space models via particle filters and the EM algorithm.
- Author
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Hamdi, Fayçal and Lellou, Chahrazed
- Subjects
EXPECTATION-maximization algorithms ,KALMAN filtering ,MONTE Carlo method ,GOODNESS-of-fit tests ,DYNAMICAL systems ,MAXIMUM likelihood statistics - Abstract
In this paper, we focus on studying the Mixed-Effects State-Space (MESS) models previously introduced by Liu et al. [Liu D, Lu T, Niu X-F, et al. Mixed-effects state-space models for analysis of longitudinal dynamic systems. Biometrics. 2011;67(2):476–485]. We propose an estimation method by combining the auxiliary particle learning and smoothing approach with the Expectation Maximization (EM) algorithm. First, we describe the technical details of the algorithm steps. Then, we evaluate their effectiveness and goodness of fit through a simulation study. Our method requires expressing the posterior distribution for the random effects using a sufficient statistic that can be updated recursively, thus enabling its application to various model formulations including non-Gaussian and nonlinear cases. Finally, we demonstrate the usefulness of our method and its capability to handle the missing data problem through an application to a real dataset. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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22. Continuous Emotion Ambiguity Prediction: Modeling With Beta Distributions.
- Author
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Bose, Deboshree, Sethu, Vidhyasaharan, and Ambikairajah, Eliathamby
- Abstract
Conventional continuous emotion prediction systems are typically trained to predict the ‘average’ of affect ratings obtained from multiple human annotators. These systems, however, ignore the ambiguity inherent in the perceived emotions, which is not captured by the ‘average rating’. This paper presents a novel ambiguity-aware continuous emotion prediction system that predicts the time-varying emotion state as a series of beta distributions. Our recent work has shown beta distributions to be an effective parametric model of a collection of affect ratings. This work develops an appropriate cost function that enables neural networks to be trained to predict beta distributions. It also investigates the choice of parameterization of the beta distribution, the choice of activation functions of the output layer, and the tractability of gradient definitions in combination with the loss function. The proposed framework is implemented using a Bag-of-Audio-Words front-end and an LSTM-based back-end and evaluated on the RECOLA dataset. In addition to comparison with baseline systems that only predict the ‘average rating’, the effectiveness with which the predictions represent ambiguity in perceived emotions is also evaluated. Experimental results reveal that the proposed approach outperforms other ambiguity-aware systems, especially when predicting valence. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Estimation for partially observed left truncation and right censored competing risks data from a generalized inverted exponential distribution with illustrations.
- Author
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Wang, Liang, Zhang, Chunfang, Wu, Shuo-Jye, Dey, Sanku, and Lio, Yuhlong
- Subjects
DISTRIBUTION (Probability theory) ,COMPETING risks ,MAXIMUM likelihood statistics ,GIBBS sampling ,FISHER information - Abstract
In this paper, studies of competing risks model are considered when the observations are left-truncated and right-censored data. When the failure times of the competing risks are distributed by a generalized inverted exponential model with same scale but different shape parameters with partially observed failure causes, statistical inference for the unknown model parameters is discussed from classical and Bayesian approaches, respectively. Maximum likelihood estimators of the unknown parameters, along with associated existence and uniqueness, are established, and the asymptotic likelihood theory is also used to construct the confidence interval via the observed Fisher information matrix. Moreover, Bayesian estimates and the corresponding highest posterior density credible intervals are also obtained based a flexible Gamma-Beta prior, and a Gibbs sampling technique is constructed to compute associated estimates. Further, under a general practical assumption with order-restriction parameter case, classical and Bayesian estimations are also established under order restriction situations, respectively. Extensive Monte-Carlo simulations are carried out to investigate the performances of our results and two real-life examples are analyzed to show the applicability of the proposed methods. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Statistical inference for a two-parameter Rayleigh distribution under generalized progressive hybrid censoring scheme.
- Author
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Xin, Ying, Zhou, Bingchang, Tang, Yaning, and Zhang, You
- Subjects
RAYLEIGH model ,INFERENTIAL statistics ,MARKOV chain Monte Carlo ,CENSORING (Statistics) ,ASYMPTOTIC distribution ,MAXIMUM likelihood statistics ,FISHER information - Abstract
The two-parameter Rayleigh distribution, as an extended distribution of the Rayleigh distribution, has been widely applied in reliability analysis. With the introduction of the location parameter, two-parameter Rayleigh distribution becomes more flexible in fitting real-data. In this paper, based on generalized progressively hybrid censored(GPHC) sample from the two-parameter Rayleigh distribution, Classical and Bayesian inferences are discussed. The Newton-Raphson(NR) and Expectation-Maximization(EM) algorithms are used to compute the maximum likelihood estimates(MLEs). As well as the asymptotic confidence interval(ACI) estimation is obtained through the asymptotic distribution theory of maximum likelihood estimation(MLE) and computation of the observed Fisher information matrix. In Bayesian frame, the estimation of unknown parameters and prediction of future observable are taken into consideration. Due to Bayesian estimation is challenging to compute precisely and for the purpose of comparison, the Lindley's approximation, the Tierney-Kadane(TK) approximation and Markov chain Monte Carlo(MCMC) method are employed to obtain Bayesian estimates. Then, combining the MCMC algorithm mentioned in the article, the one- and two- samples Bayesian prediction are obtained. Finally, the simulation results are provided and a real-life data set is used for illustration purpose. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. Maximum likelihood inference for a class of discrete-time Markov switching time series models with multiple delays.
- Author
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Martínez-Ordoñez, José. A., López-Santiago, Javier, and Miguez, Joaquín
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TIME series analysis ,MAXIMUM likelihood detection ,EL Nino ,DELAY differential equations ,STOCHASTIC differential equations ,MAXIMUM likelihood statistics ,NONLINEAR dynamical systems ,STOCHASTIC systems ,PARAMETER estimation - Abstract
Autoregressive Markov switching (ARMS) time series models are used to represent real-world signals whose dynamics may change over time. They have found application in many areas of the natural and social sciences, as well as in engineering. In general, inference in this kind of systems involves two problems: (a) detecting the number of distinct dynamical models that the signal may adopt and (b) estimating any unknown parameters in these models. In this paper, we introduce a new class of nonlinear ARMS time series models with delays that includes, among others, many systems resulting from the discretisation of stochastic delay differential equations (DDEs). Remarkably, this class includes cases in which the discretisation time grid is not necessarily aligned with the delays of the DDE, resulting in discrete-time ARMS models with real (non-integer) delays. The incorporation of real, possibly long, delays is a key departure compared to typical ARMS models in the literature. We describe methods for the maximum likelihood detection of the number of dynamical modes and the estimation of unknown parameters (including the possibly non-integer delays) and illustrate their application with a nonlinear ARMS model of El Niño–southern oscillation (ENSO) phenomenon. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Estimating sensitivity with the Bruceton method: Setting the record straight.
- Author
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Christensen, Dennis, Novik, Geir Petter, and Unneberg, Erik
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RESEARCH personnel ,ECONOMIC stimulus ,EXPERIMENTAL design - Abstract
Accurate estimates of sensitivities of energetic materials are crucial for ensuring safe production, transport, usage and destruction of explosives. When estimating sensitivities, researchers most commonly follow the NATO standard guidelines (STANAGs), in which the Bruceton method is imposed. Introduced in 1948, this method contains (i) an experimental design for choosing which stimulus levels to measure at and (ii) a recipe for computing sensitivity estimates. Although the former experimental design is supported by both theory and simulations, few modern researchers are aware that the latter recipe was only intended as a pen‐and‐paper approximation of the maximum likelihood estimates, which are easy to compute today. The persistent use of this outdated approximation has led to many unfortunate misconceptions amongst users of the Bruceton method, including the rejection of many perfectly valid data sets and neglect of uncertainty assessments via confidence intervals. This is both dangerous and unnecessarily wasteful. This paper sets the record straight and explains how researchers should estimate sensitivity via maximum likelihood estimation and how to construct confidence intervals. It also shows explicitly how wasteful said approximation is via both simulations and with real data. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Predictive modelling of critical variables for improving HVOF coating using gamma regression models.
- Author
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Rannetbauer, Wolfgang, Hubmer, Simon, Hambrock, Carina, and Ramlau, Ronny
- Subjects
METAL spraying ,COATING processes ,REGRESSION analysis ,SURFACE coatings ,PREDICTION models ,ATOMIZERS ,SURFACES (Technology) - Abstract
Thermal spray coating is a critical process in many industries, involving the application of coatings to surfaces to enhance their functionality. This paper proposes a framework for modelling and predicting critical target variables in thermal spray coating processes, based on the application of statistical design of experiments (DoE) and the modelling of the data using generalized linear models (GLMs) with a particular emphasis on gamma regression. Experimental data obtained from thermal spray coating trials are used to validate the presented approach, demonstrating that it is able to accurately model and predict critical target variables. As such, the framework has significant potential for the optimization of thermal spray coating processes, and can contribute to the development of more efficient and effective coating technologies in various industries. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Inference of Constant-Stress Model of Fréchet Distribution under a Maximum Ranked Set Sampling with Unequal Samples.
- Author
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Liu, Jia, Wang, Liang, Tripathi, Yogesh Mani, and Lio, Yuhlong
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DISTRIBUTION (Probability theory) ,ACCELERATED life testing ,MAXIMUM likelihood statistics ,BAYESIAN analysis ,CONFIDENCE intervals - Abstract
This paper explores the inference for a constant-stress accelerated life test under a ranked set sampling scenario. When the lifetime of products follows the Fréchet distribution, and the failure times are collected under a maximum ranked set sampling with unequal samples, classical and Bayesian approaches are proposed, respectively. Maximum likelihood estimators along with the existence and uniqueness of model parameters are established, and the corresponding asymptotic confidence intervals are constructed based on asymptotic theory. Under squared error loss, Bayesian estimation and highest posterior density confidence intervals are provided, and an associated Monte-Carlo sampling algorithm is proposed for complex posterior computation. Finally, extensive simulation studies are conducted to demonstrate the performance of different methods, and a real-data example is also presented for applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Bayesian estimation of finite buffer size in single server Markovian queuing system.
- Author
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Basak, Arpita and Choudhury, Amit
- Abstract
For operating any new finite capacity (say K) queuing system in which customers arrive according to a Poisson process and are served by a single server under exponential service time (in Kendall's notation M/M/1/K system), the assumption of fixing K and estimating the parameter traffic intensity ρ , is quite practical. But in situation of any pre-existing M/M/1/K queuing system, it is essential to determine an estimator of K to increase system efficiency for fixed value of ρ . This paper therefore considered the problem of estimating the parameter finite buffer (K). A Bayes estimator of K is proposed and compared it with classical estimator based on maximum likelihood principal, under the assumption that ρ is known. A simulation study is carried out to establish the efficacy and effectiveness of the proposed approaches. A real life situation is analyzed to illustrate the applicability of the developed algorithms. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. The accelerated failure time regression model under the extended-exponential distribution with survival analysis.
- Author
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Kariuki, Veronica, Wanjoya, Anthony, Ngesa, Oscar, Mansour, Mahmoud M., Abd Elrazik, Enayat M., and Afify, Ahmed Z.
- Subjects
REGRESSION analysis ,CENSORING (Statistics) ,HAZARD function (Statistics) ,MAXIMUM likelihood statistics ,DISTRIBUTION (Probability theory) ,SURVIVAL analysis (Biometry) - Abstract
In this paper, we propose a parametric accelerated failure time (AFT) hazard-based regression model with the extended alpha-power exponential (EAPE) baseline distribution. The proposed model is called the extended alpha-power exponential-AFT (EAPE-AFT) regression model. We show that the EAPE distribution is closed under the AFT model. The parameters of the proposed EAPE-AFT model have been estimated by using the method of maximum likelihood estimation. An extensive simulation study was also conducted to examine the performance of the estimates under several scenarios based on the shapes of the baseline hazard function. Finally, real-life censored survival data has been used to illustrate the applicability of the proposed model. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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31. Simulation Study for Estimating the Parameters and Reliability Function of Weighted Exponential Distribution with Fuzzy Data.
- Author
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Hussein, Lamyaa Khalid and Al-Noor, Nadia Hashim
- Subjects
DISTRIBUTION (Probability theory) ,EXPONENTIAL functions ,NEWTON-Raphson method ,BAYES' estimation ,ESTIMATION theory ,ERROR functions - Abstract
This paper investigates the estimation of the two unknown parameters and the reliability function of the weighted exponential distribution. It explores Bayesian and non-Bayesian (maximum likelihood) estimation methods when the information available is in the form of fuzzy data. The Newton-Raphson algorithm is used to obtain the maximum likelihood estimates. In Bayes estimation, the symmetric squared error loss function is used. This loss function links equal importance to the losses due to overestimating and underestimating equal magnitude. Lindley approximation procedure in Bayesian estimation theory is used to evaluate the ratio of integrals. A comparative analysis using simulation is carried out to evaluate the performance of the obtained parameters estimators using mean squared error criteria and the performance of the obtained reliability estimators using integrated mean squared error criteria. The simulation results demonstrate that, for different sample sizes, the performance of Bayes estimates surpasses the maximum likelihood, and that all estimators perform consistently. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. 双应力恒加寿命试验可靠性评估模型.
- Author
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刘亚成 and 刘君
- Abstract
Copyright of Journal of Nanchang University (Engineering & Technology) is the property of Nanchang University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
- Published
- 2024
33. PSO-guided optimal estimator enabled regularized adaptive extended Kalman filter with unknown inputs for dynamic nonlinear indoor thermal state estimation.
- Author
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Das, Bed Prakash, Das Sharma, Kaushik, Chatterjee, Amitava, and Bera, Jitendra Nath
- Subjects
KALMAN filtering ,MAXIMUM likelihood statistics ,ADAPTIVE filters ,AIR conditioning ,HUMIDITY - Abstract
This paper presents a particle swarm optimization-guided maximum likelihood estimation enabled (MLE) adaptive extended Kalman filter (EKF) with unknown inputs algorithm for estimating the dynamic nonlinear thermal states for an indoor heating ventilation and air conditioning system. The concept of MLE has been introduced to enhance the speed of convergence of the filtering parameters in adaptive EKF. The nonlinear indoor environment has been modelled employing equivalent RC network taking relative humidity into account. At the outset, an EKF-based method accommodating the unknown inputs and an adaptive estimator-based variant of it are developed for estimating the temperature of the walls of a laboratory-scale realistic environment. Subsequently the proposed scheme comes into play to deal with the scenarios associated with undesirable divergence and poor initialization utilizing the metaheuristically adapted optimal regularizer. The proposed technique outperforms the other contemporary state-of-the-art counterparts in terms of mean squared error. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
34. The Additive Xgamma-Burr XII Distribution: Properties, Estimation and Applications.
- Author
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Mohammad, Hebatalla H., Alamri, Faten S., Salem, Heba N., and EL-Helbawy, Abeer A.
- Subjects
HAZARD function (Statistics) ,PROBABILITY density function ,MAXIMUM likelihood statistics ,COMPETING risks ,CONFIDENCE intervals - Abstract
This paper introduces a new four-parameter additive model, named xgamma-Burr XII distribution, by considering two competing risks: the former has the xgamma distribution and the latter has the Burr XII distribution. A graphical description of the xgamma-Burr XII distribution is presented, including plots of the probability density function, hazard rate and reversed hazard rate functions. The xgamma-Burr XII density has different shapes such as decreasing, unimodal, approximately symmetric and decreasing-unimodal. The main statistical properties of the proposed model are studied. The unknown model parameters, reliability, hazard rate and reversed hazard rate functions are estimated via the maximum likelihood method. The asymptotic confidence intervals of the parameters, reliability function, hazard rate function and reversed hazard rate function are also obtained. A simulation study is carried out to evaluate the performance of the maximum likelihood estimates. In addition, three real data are applied to show the superiority of the xgamma-Burr XII distribution over some known distributions in real-life applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
35. Uncertain logistic regression models.
- Author
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Jinling Gao and Zengtai Gong
- Subjects
REGRESSION analysis ,NONLINEAR regression ,LOGISTIC regression analysis ,ECONOMIC forecasting ,NONLINEAR analysis ,DATA mining - Abstract
Logistic regression is a generalized nonlinear regression analysis model and is often used for data mining, automatic disease diagnosis, economic prediction, and other fields. In this paper, we first aimed to introduce the concept of uncertain logistic regression based on the uncertainty theory, as well as investigating the likelihood function in the sense of uncertain measure to represent the likelihood of unknown parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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36. A New Modification of the Weibull Distribution: Model, Theory, and Analyzing Engineering Data Sets.
- Author
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Alshanbari, Huda M., Ahmad, Zubair, El-Bagoury, Abd Al-Aziz Hosni, Odhah, Omalsad Hamood, and Rao, Gadde Srinivasa
- Subjects
STATISTICAL models ,CIVIL engineers ,CIVIL engineering ,MAXIMUM likelihood statistics ,FRACTURE toughness - Abstract
Symmetrical as well as asymmetrical statistical models play a prominent role in describing and predicting the real-world phenomena of nature. Among other fields, these models are very useful for modeling data in the sector of civil engineering. Due to the applicability of the statistical models in civil engineering and other related sectors, this paper offers a statistical methodology to improve the distributional flexibility of traditional models. The suggested method/approach is called the extended-X family of distributions. The proposed method has the ability to generate symmetrical and asymmetrical probability distributions. Based on the extended-X family approach, an updated version of the Weibull model, namely, the extended Weibull model, is studied. The proposed model is very flexible and has the ability to capture the symmetrical and asymmetrical shapes of its density function. For the extended-X method, the estimation of parameters, a simulation study, and some mathematical properties are derived. Finally, the practical illustration/usefulness of the suggested model is shown by analyzing two data sets taken from the field of engineering. Both data sets represent the fracture toughness of alumina (Al
2 O3 ). [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
37. A robust fusion bus frequency estimation method to improve frequency oscillation damping in power systems.
- Author
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Farahani, Ali, Abolmasoumi, Amir H., Mili, Lamine, and Bayat, Mohammad
- Subjects
FREQUENCIES of oscillating systems ,PHASE-locked loops ,FREQUENCY dividers ,OUTLIER detection ,KALMAN filtering ,BUSES - Abstract
This paper proposes a new robust method for accurately and reliably estimating remote bus frequencies in a power system. Two different measurement sources for the remote bus frequency are considered, that is, the ideal Frequency Divider (FD) and the Synchronous Reference Frame Phase Locked Loops (SRF‐PLLs). Each measurement signal encounters different uncertainties and data quality issues. In this paper, both data sources are employed and fused together to better estimate the remote bus frequencies. To this end, the model structure of the power system is selected and an Unscented Kalman Filter (UKF) is utilized together with a fusion covariance intersection method to enhance the accuracy of the estimated bus frequency. Since the fusion estimation method fails in case of quality issues on both channels, a robust Generalized Maximum‐likelihood UKF (GM‐UKF) using a novel outlier detection criteria is developed. The impact of the resulting robust fusion filter on the estimation of the remote bus frequencies and on the performance of WAPSS, which makes use of the estimated frequencies as the feedback signal, is examined via simulations. The results demonstrate the excellent performance and reliability of the proposed method in dealing with noise filtering and outlier suppression while ensuring a high statistical efficiency. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Properties and Parameter Estimation of the Partly-Exponential Distribution.
- Author
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Roopmok, Nalattaporn, Duangsaphon, Monthira, and Volodin, Andrei
- Abstract
The partly-exponential distribution was introduced in the paper by Atikankul et al. in 2021, but no properties of this distribution have been investigated. In this paper, we derive various theoretical properties such as the cumulative distribution function, the moment generating function, the first three moments, the characteristic function, and the mode. The maximum likelihood estimation is used to estimate the parameters. Moreover, the Wald and the profile likelihood approaches are used for interval estimation. A simulation study is conducted to examine the mean square error and bias of the maximum likelihood estimators, as well as the coverage probability of the both confidence intervals. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
39. ON THE DISCRETE DISTRIBUTION GENERATED BY LEVY PROBABILITY
- Author
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Farbod, Davood and Basirat, Maryam
- Published
- 2024
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40. Inference for multicomponent stress–strength reliability based on unit generalized Rayleigh distribution
- Author
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Jha, Mayank Kumar, Singh, Kundan, Dey, Sanku, Wang, Liang, and Tripathi, Yogesh Mani
- Published
- 2024
- Full Text
- View/download PDF
41. A γ-power stochastic Lundqvist-Korf diffusion process: Computational aspects and simulation.
- Author
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Abdenbi, El Azri and Ahmed, Nafidi
- Subjects
INFERENTIAL statistics ,ENERGY consumption ,ALGORITHMS ,NONLINEAR equations ,PROBABILITY theory - Abstract
In this paper, we introduce a new family of stochastic Lundqvist-Korf diffusion process, defined from a g-power of the Lundqvist-Korf diffusion process. First, we determine the probabilistic characteristics of the process, such as its analytic expression, the transition probability density function from the corresponding It ˆo stochastic differential equation and obtain the conditional and non-conditional mean functions. We then study the statistical inference in this process. The parameters of this process are estimated by using the maximum likelihood estimation method with discrete sampling, thus we obtain a nonlinear equation, which is achieved via the simulated annealing algorithm. Finally, the results of the paper are applied to simulated data. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
42. A Numerical Approach for Evaluating the Time-Dependent Distribution of a Quasi Birth-Death Process.
- Author
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Mandjes, Michel and Sollie, Birgit
- Subjects
MAXIMUM likelihood statistics ,MARKOV processes ,TIME series analysis - Abstract
This paper considers a continuous-time quasi birth-death (qbd) process, which informally can be seen as a birth-death process of which the parameters are modulated by an external continuous-time Markov chain. The aim is to numerically approximate the time-dependent distribution of the resulting bivariate Markov process in an accurate and efficient way. An approach based on the Erlangization principle is proposed and formally justified. Its performance is investigated and compared with two existing approaches: one based on numerical evaluation of the matrix exponential underlying the qbd process, and one based on the uniformization technique. It is shown that in many settings the approach based on Erlangization is faster than the other approaches, while still being highly accurate. In the last part of the paper, we demonstrate the use of the developed technique in the context of the evaluation of the likelihood pertaining to a time series, which can then be optimized over its parameters to obtain the maximum likelihood estimator. More specifically, through a series of examples with simulated and real-life data, we show how it can be deployed in model selection problems that involve the choice between a qbd and its non-modulated counterpart. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
43. Instance-Dependent Positive and Unlabeled Learning With Labeling Bias Estimation.
- Author
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Gong, Chen, Wang, Qizhou, Liu, Tongliang, Han, Bo, You, Jane, Yang, Jian, and Tao, Dacheng
- Subjects
ESTIMATION bias ,MAXIMUM likelihood statistics ,MATHEMATICAL optimization ,RANDOM variables ,PRODUCTION scheduling - Abstract
This paper studies instance-dependent Positive and Unlabeled (PU) classification, where whether a positive example will be labeled (indicated by $s$ s ) is not only related to the class label $y$ y , but also depends on the observation $\mathbf {x}$ x . Therefore, the labeling probability on positive examples is not uniform as previous works assumed, but is biased to some simple or critical data points. To depict the above dependency relationship, a graphical model is built in this paper which further leads to a maximization problem on the induced likelihood function regarding $P(s,y|\mathbf {x})$ P (s , y | x) . By utilizing the well-known EM and Adam optimization techniques, the labeling probability of any positive example $P(s=1|y=1,\mathbf {x})$ P (s = 1 | y = 1 , x) as well as the classifier induced by $P(y|\mathbf {x})$ P (y | x) can be acquired. Theoretically, we prove that the critical solution always exists, and is locally unique for linear model if some sufficient conditions are met. Moreover, we upper bound the generalization error for both linear logistic and non-linear network instantiations of our algorithm, with the convergence rate of expected risk to empirical risk as $\mathcal {O}(1/\sqrt{k}+1/\sqrt{n-k}+1/\sqrt{n})$ O (1 / k + 1 / n - k + 1 / n) ($k$ k and $n$ n are the sizes of positive set and the entire training set, respectively). Empirically, we compare our method with state-of-the-art instance-independent and instance-dependent PU algorithms on a wide range of synthetic, benchmark and real-world datasets, and the experimental results firmly demonstrate the advantage of the proposed method over the existing PU approaches. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
44. A Physics-Informed Deep Learning Paradigm for Traffic State and Fundamental Diagram Estimation.
- Author
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Shi, Rongye, Mo, Zhaobin, Huang, Kuang, Di, Xuan, and Du, Qiang
- Abstract
Traffic state estimation (TSE) bifurcates into two main categories, model-driven and data-driven (e.g., machine learning, ML) approaches, while each suffers from either deficient physics or small data. To mitigate these limitations, recent studies introduced hybrid methods, such as physics-informed deep learning (PIDL), which contains both model-driven and data-driven components. This paper contributes an improved paradigm, called physics-informed deep learning with a fundamental diagram learner (PIDL + FDL), which integrates ML terms into the model-driven component to learn a functional form of a fundamental diagram (FD), i.e., a mapping from traffic density to flow or velocity. The proposed PIDL + FDL has the advantages of performing the TSE learning, model parameter identification, and FD estimation simultaneously. This paper focuses on highway TSE with observed data from loop detectors, using traffic density or velocity as traffic variables. We demonstrate the use of PIDL + FDL to solve popular first-order and second-order traffic flow models and reconstruct the FD relation as well as model parameters that are outside the FD term. We then evaluate the PIDL + FDL-based TSE using the Next Generation SIMulation (NGSIM) dataset. The experimental results show the superiority of the PIDL + FDL in terms of improved estimation accuracy and data efficiency over advanced baseline TSE methods, and additionally, the capacity to properly learn the unknown underlying FD relation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
45. Random Matrix Time Series
- Author
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Teng, Peiyuan and Xu, Min
- Published
- 2023
- Full Text
- View/download PDF
46. On the Maximum Likelihood Estimation of Population and Domain Means
- Author
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Wywiał, Janusz L.
- Published
- 2023
- Full Text
- View/download PDF
47. A novel flexible exponent power-X family of distributions with applications to COVID-19 mortality rate in Mexico and Canada.
- Author
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Shah, Zubir, Khan, Dost Muhammad, Khan, Imad, Ahmad, Bakhtiyar, Jeridi, Mouna, and Al-Marzouki, Sanaa
- Subjects
MONTE Carlo method ,AKAIKE information criterion ,ORDER statistics ,DEATH rate ,COVID-19 ,MAXIMUM likelihood statistics ,EXPONENTS - Abstract
This paper aims to introduce a novel family of probability distributions by the well-known method of the T–X family of distributions. The proposed family is called a "Novel Generalized Exponent Power X Family" of distributions. A three-parameters special sub-model of the proposed method is derived and named a "Novel Generalized Exponent Power Weibull" distribution (NGEP-Wei for short). For the proposed family, some statistical properties are derived including the hazard rate function, moments, moment generating function, order statistics, residual life, and reverse residual life. The well-known method of estimation, the maximum likelihood estimation method is used for estimating the model parameters. Besides, a comprehensive Monte Carlo simulation study is conducted to assess the efficacy of this estimation method. Finally, the model selection criterion such as Akaike information criterion (AINC), the correct information criterion (CINC), the Bayesian information criterion (BINC), the Hannan–Quinn information criterion (HQINC), the Cramer–von-Misses (CRMI), and the ANDA (Anderson–Darling) are used for comparison purpose. The comparison of the NGEP-Wei with other rival distributions is made by Two COVID-19 data sets. In terms of performance, we show that the proposed method outperforms the other competing methods included in this study. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Step‐stress life‐testing under tampered random variable modeling for Weibull distribution in presence of competing risk data.
- Author
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Sultana, Farha, Çetinkaya, Çağatay, and Kundu, Debasis
- Subjects
- *
COMPETING risks , *MAXIMUM likelihood statistics , *CENSORING (Statistics) , *WEIBULL distribution , *BAYESIAN field theory , *BAYESIAN analysis , *RANDOM variables - Abstract
In this paper, we have considered the classical and Bayesian inference of the unknown parameters of the lifetime distribution based on the observations obtained from a simple step‐stress life‐testing (SSLT) experiment and when more than one cause of failures are observed. We have used the Tampered Random Variable (TRV) approach. The main advantage of the TRV approach is that it can be easily extended to a multiple step‐stress model as well as for different lifetime distributions. In this paper, it is assumed that the lifetime of the experimental units at each stress level follows Weibull distribution with the same shape parameter and different scale parameters. Further, we have introduced different tempering co‐efficient for different causes of failures. The maximum likelihood estimators and the associated asymptotic confidence intervals are obtained based on Type‐II censored observations. Further, we have considered the Bayesian inference of the unknown model parameters based on a fairly general class prior distributions. An extensive simulation study is performed to examine the performances of the proposed method, and the analysis of a real data set has been provided to show how the method can be used in practice. We have compared the TRV model with some of the other existing models, and the TRV model provides a better fit in terms of information theoretic criteria. We have also provided some optimality criteria, to determine the optimal stress change time and some sensitivity analyses have been performed. Most of the methods can be extended for other lifetime distributions also. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. On the theory of order statistics of the flexible Lomax distribution.
- Author
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Jamal, Farrukh, Ijaz, Muhammad, Mustafa, Ghulam, Khan, Sadaf, and Shafiq, Shakaiba
- Subjects
ORDER statistics ,MAXIMUM likelihood statistics - Abstract
This paper studies the flexible Lomax distribution's order statistics with graphical and numerical findings. Along with the quantitative measurements, some plots are furnished, including those for the skewness and kurtosis measures. We will dwell on the numerous results that relate to statistics of moments of order. We consider the single and product moment of order statistics from the new distribution. Further, we establish some recurrence relation for single moments of order statistics. We have sought to apply the derived relations to empirically evaluate the moments of smallest (largest) order statistics to establish well-known moments and related measures. For order statistics of a flexible Lomax distribution, exact analytical expressions of entropy, residual entropy, and past latent entropy are determined. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. Estimating flexibility preferences to resolve temporal scheduling conflicts in activity-based modelling.
- Author
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Manser, Patrick, Haering, Tom, Hillel, Tim, Pougala, Janody, Krueger, Rico, and Bierlaire, Michel
- Subjects
DISCRETE choice models ,CAPABILITIES approach (Social sciences) ,SCHEDULING - Abstract
This paper presents a novel activity-based demand model that combines an optimisation framework for continuous temporal scheduling decisions (i.e. activity timings and durations) with traditional discrete choice models for non-temporal choice dimensions (i.e. activity participation, number and type of tours, and destinations). The central idea of our approach is that individuals resolve temporal scheduling conflicts that arise from overlapping activities, e.g. needing to work and desiring to shop at the same time, in order to maximise their daily utility. Flexibility parameters capture behavioural preferences that penalise deviations from desired timings. This framework has three advantages over existing activity-based modelling approaches: (i) the time conflicts between different temporal scheduling decisions including the activity sequence are treated jointly; (ii) flexibility parameters follow a utility maximisation approach; and (iii) the framework can be used to estimate and simulate a city-scale case study in reasonable time. We introduce an estimation routine that allows flexibility parameters to be estimated using real-world observations as well as a simulation routine to efficiently resolve temporal conflicts using an optimisation model. The framework is applied to the full-time workers of a synthetic population for the city of Lausanne, Switzerland. We validate the model results against reported schedules. The results demonstrate the capabilities of our approach to reproduce empirical observations in a real-world case study. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
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