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Improvement of X-Band Polarization Radar Melting Layer Recognition by the bayesian method and ITS Impact on Hydrometeor Classification

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Advances in Atmospheric Sciences 2020年第1期37卷 105-116页

作者： Jianli MA Zhiqun HU Meilin YANG Siteng LI Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089China State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China

Using melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation coefficient(CC)in the ML and NML are obtained in several stable precipitation *** prior probability density distributions(PDDs)of the ZH,ZDR and CC are calculated first,and then the probabilities of ZH,ZDR and CC at each radar gate are determined(PBB in the ML and PNB in the NML)by the bayesian *** PBB>PNB the gate belongs to the ML,and when PBBbayesian method are contrasUsing melting layer(ML)and non-melting layer(NML)data observed with the X-band dual linear polarization Doppler weather radar(X-POL)in Shunyi,Beijing,the reflectivity(ZH),differential reflectivity(ZDR),and correlation coefficient(CC)in the ML and NML are obtained in several stable precipitation *** prior probability density distributions(PDDs)of the ZH,ZDR and CC are calculated first,and then the probabilities of ZH,ZDR and CC at each radar gate are determined(PBB in the ML and PNB in the NML)by the bayesian *** PBB>PNB the gate belongs to the ML,and when PBBbayesian method are contrasted under the conditions of the independent PDDs and joint PDDs of the ZH,ZDR and *** results suggest that MLs can be identified effectively,although there are slight differences between the two *** the values of the polarization parameters are similar in light rain and dry snow,it is difficult for the polarization radar to distinguish *** using the bayesian method to identify the ML,light rain and dry snow can be effectively separated with the X-POL observed *** under the conditions of the independent PDDs and joint PDDs of the ZH,ZDR and *** results suggest that MLs can be identified effectively,a

关键词： X-band polarimetric radar bayesian method melting layer identification hydrometeor classification

A bayesian method for comprehensive water quality evaluation of the Danjiangkou Reservoir water source area, for the middle route of the South-to-North Water Diversion Project in China

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Frontiers of Earth Science 2014年第2期8卷 242-250页

作者： Fangbing MA Chunhui LI Xuan WANG Zhifeng YANG Chengchun SUN Peiyu LIANG Key Laboratory for Water and Sediment Sciences of Ministry of Education School of Environment Beijing Normal University Beijing 100875 China State Key Laboratory for Water Environment Simulation School of Environment Beijing Normal University Beijing 100875 China Shidu Town People's Government Beijing 102411 China

The Danjiangkou Reservoir is the water source for the middle route of the South-to-North Water Diversion Project in China. Thus, its water quality status is of great concern. Five water quality indicators （dissolved oxygen, permanganate index, ammonia nitrogen, total nitrogen, and total phosphorus）, were measured at three monitoring sites （the Danjiangkou Reservoir dam, the Hejiawan and the Jiangbei bridge）, to investigate changing trends, and spatiotemporal characteristics of water quality in the Danjiangkou Reservoir area from January 2006 to May 2012. We then applied a bayesian statistical method to evaluate the water quality comprehensively. The normal distribution sampling method was used to calculate likelihood, and the entropy weight method was used to determine indicator weights for variables of interest in to the study. The results indicated that concentrations of all five indicators increased during the last six years. In addition, the water quality in the reservoir was worse during the wet season （from May to October）, than during the dry season （from November to April of the next year）. Overall, the probability of the water＇s belonging to quality category of type lI, according to environmental quality standards for surface water in China, was 27.7%-33.7%, larger than that of its belonging to the other four water quality types. The increasing concentrations of nutrients could result in eutrophication of the Danjiangkou Reser- voir. This method reduced the subjectivity that is commonly associated with determining indicator weights and artificial classifications, achieving more reliable results. These results indicate that it is important for the interbasin water diversion project to implement integrated water quality management in the Danjiangkou Reservoir area.

关键词： water quality evaluation Danjiangkou Reser-voir bayesian method normal distribution samplingmethod entropy weight method

Some results of classification problem by bayesian method and application incredit operation

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Statistical Theory and Related Fields 2018年第2期2卷 150-157页

作者： Tai Vovan College of Natural Science Can Tho UniversityCan ThoVietnam

This study proposes some results in classifying by bayesian method. There are upper and lowerbounds of the Bayes error as well as its determination in case of one dimension and multidimensions. Based on the proposals for estimating of probability density functions, calculatingthe Bayes error and determining the prior probability, we establish an algorithm to evaluateability of customers to pay debts at banks. This algorithm has been performed by the Matlabprocedure that can be applied well with real data. The proposed algorithm is tested by the realapplication at a bank in Viet Nam that obtains the best results in comparing with the existingapproaches.

关键词： bayesian method classification error credit operation prior probability

A bayesian Updating method for Non-Probabilistic Reliability Assessment of Structures with Performance Test Data

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Computer Modeling in Engineering & Sciences 2020年第11期125卷 777-800页

作者： Jiaqi He Yangjun Luo Province Key Laboratory of Advanced Technology for Aerospace Vehicles School of Aeronautics and AstronauticsDalian University of TechnologyDalian116024China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian116024China

For structures that only the predicted bounds of uncertainties are available,this study proposes a bayesianmethod to logically evaluate the nonprobabilistic reliability of structures based on multi-ellipsoid convex model and performance test *** to the given interval ranges of uncertainties,we determine the initial characteristic parameters of a multi-ellipsoid convex ***,to update the plausibility of characteristic parameters,a bayesian network for the information fusion of prior uncertainty knowledge and subsequent performance test data is ***,an updated multi-ellipsoid set with the maximum likelihood of the performance test data can be *** credible non-probabilistic reliability index is calculated based on the Kriging-based surrogate model of the performance *** numerical examples are presented to validate the proposed bayesian updating method.

关键词： Convex model bayesian method non-probabilistic reliability information fusion

A Reliability Improvement Predictive Approach to Software Testing with bayesian method

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A Reliability Improvement Predictive Approach to Software Te...

Online remaining-useful-life estimation with a bayesian-updated expectation-conditional-maximization algorithm and a modified bayesian-model-averaging method

第二十九届中国控制会议

作者： BAI Cheng-Gang,JIANG Chang-Hai,CAI Kai-Yuan National Key Laboratory of Science and Technology on Holistic Control Department of Automatic Control,Beihang University,Beijing 100191,P.R.China

The capability of improving software reliability is one of the main objectives of software ***,the previous testing methods did not pay much attention to how to improve software testing strategy based on software reliability *** relationship between software testing and software reliability is very complex and this is mainly due to the complexity of software products and development *** software testing strategy with improving reliability on line needs to possess the ability to predict *** predictive control provides a good framework to improve predictive effect on ***,one of the main issues in model predictive control is how to estimate the concern *** this case,bayesian method is used to estimate the concern parameter:*** proposed reliabilityimprovement predictive approach to software testing with bayesian method can optimize test allocation scheme on *** case study shows that it is not definitely true for a software testing method that can find more defects than others can get higher *** the case study also shows that the proposed approach can get better result in the sense of improving reliability than random testing.

关键词： Software Testing Software Reliability Model Predictive Control bayesian method

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Science China(Information Sciences) 2021年第1期64卷 146-161页

作者： Yong YU Xiaosheng SI Changhua HU Jianfei ZHENG Jianxun ZHANG School of Missile Engineering Rocket Force University of Engineering School of Mechanical Engineering Xi'an Jiaotong University

Online remaining-useful-life(RUL) estimation is an effective method with respect to ensuring the safety of complex-huge systems. Generally, current methods assume a specific degradation model when degradation values are observed in the initial degradation phase. However, this assumption may not always be robust enough owing to the often-ambiguous inherent incipient-degradation characteristic. Therefore,besides model-parameter uncertainty, the uncertainty of the degradation model is worth examining in online RUL estimations. In this paper, a bayesian-updated expectation-conditional-maximization(ECM) algorithm is adopted to address the uncertainty of prior parameters, and a modified bayesian-model-averaging method is used to deal with the uncertainty of the degradation model. Then, simulation studies are conducted to analyze the effectiveness of the proposed fusion algorithm. Results suggest that the bayesian-updated ECM algorithm and modified bayesian-model-averaging method effectively address the associated uncertainties of model parameters and the degradation model itself. Finally, we apply the proposed fusion algorithm to predict the RUL of a gyroscope.

关键词： online RUL estimation parameter uncertainty model uncertainty bayesian method ECM algorithm bayesian model averaging

Performance analysis of empirical models for predicting rock mass deformation modulus using regression and bayesian methods

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第6期12卷 1263-1271页

作者： Adeyemi Emman Aladejare Musa Adebayo Idris Oulu Mining School University of OuluOuluFinland Division of Mining and Geotechnical Engineering Department of CivilEnvironmental and Natural Resources EngineeringLuleåUniversity of TechnologyLuleåSweden

Deformation modulus of rock mass is one of the input parameters to most rock engineering designs and *** field tests for determination of deformation modulus are cumbersome,expensive and *** has prompted the development of various regression equations to estimate deformation modulus from results of rock mass classifications,with rock mass rating(RMR)being one of the frequently used *** regression equations are of different types ranging from linear to nonlinear functions like power and *** method has recently been developed to incorporate regression equations into a bayesian framework to provide better estimates of geotechnical *** question of whether bayesian method improves the estimation of geotechnical properties in all circumstances remains ***,a comparative study was conducted to assess the performances of regression and bayesian methods when they are used to characterize deformation modulus from the same set of RMR data obtained from two project *** study also investigated the performance of different types of regression equations in estimation of the deformation ***,probability distributions and prediction indicators were used to assess the performances of regression and bayesian methods and different types of regression *** was found that power and exponential types of regression equations provide a better estimate than linear regression *** addition,it was discovered that the ability of the bayesian method to provide better estimates of deformation modulus than regression method depends on the quality and quantity of input data as well as the type of the regression equation.

关键词： Deformation modulus Rock mass Regression equation bayesian method Performance analysis Rock mass rating(RMR)

bayesian analysis on non-resonant behavior of 12C+12C fusion reaction at sub-barrier energies

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Chinese Physics C 2022年第6期46卷 174-182页

作者：骆天鹏温培威林承键杨磊贾会明杨峰黄大湖常昶张明昊杨赟莫腾欢马南茹 China Institute of Atomic Energy Beijing 102413China College of Physics and Technology&Guangxi Key Laboratory of Nuclear Physics and Technology Guangxi Normal UniversityGuilin 541004China

Controversies exist among experiments and theories on the S^(*)factor of the astrophysical important reaction ^(12)C+^(12)C for energies below 3 *** frequentist approaches have been used so far for data analysis,and the confidence levels or theoretical errors are not available from previous theoretical *** this study,the bayesian method is employed to provide theoretical predictions and its 1σconfidence level based on all the currently available experimental data for the first *** improved coupled-channels model CCFULL-FEM implemented with the finite element method as well as the Markov chain Monte Carlo approach emcee are adopted to analyze the non-resonant behavior of this *** posterior distribution of the Woods-Saxon potential parameters is *** with the widely used frequentist method MIGRAD within the Minuit minimization program,the bayesian method has a significant advantage for exploring the potential parameter *** the existing experimental data measured down to subbarrier energies are considered,the potential parameters are constrained to a very narrow range,and the predictions of the S^(*) factor showed no sharp decrease in the low-energy region.

关键词： bayesian method coupled channels method carbon fusion reaction astrophysical S-factor

Differences in parameter estimates derived from various methods for the ORYZA(v3) Model

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Journal of Integrative Agriculture 2022年第2期21卷 375-388页

作者： TAN Jun-wei DUAN Qing-yun GONG Wei DI Zhen-hua College of Water Resources and Civil Engineering China Agricultural UniversityBeijing 100083P.R.China College of Water Resources and Hydrology Hohai UniversityNanjing 210098P.R.China Institute of Land Surface System and Sustainable Development Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875P.R.China

Parameter estimation is always a difficult issue for crop model users, and inaccurate parameter values will result in deceptive model predictions. Parameter values may vary with different inversion methods due to equifinality and differences in the estimating processes. Therefore, it is of great importance to evaluate the factors which may influence parameter estimates and to make a comparison of the current widely-used methods. In this study, three popular frequentist methods(SCE-UA, GA and PEST) and two bayesian-based methods(GLUE and MCMC-AM) were applied to estimate nine cultivar parameters using the ORYZA(v3) Model. The results showed that there were substantial differences between the parameter estimates derived by the different methods, and they had strong effects on model predictions. The parameter estimates given by the frequentist methods were obviously sensitive to initial values, and the extent of the sensitivity varied with algorithms and objective functions. Among the frequentist methods, the SCE-UA was recommended due to the balance between stable convergence and high efficiency. All the parameter estimates remarkably improved the goodness of model-fit, and the parameter estimates derived from the bayesian-based methods had relatively worse performance compared to the frequentist methods. In particular, the parameter estimates with the highest probability density of posterior distributions derived from the MCMC-AM method(MCMC_P_(max)) led to results equivalent to those derived from the frequentist methods, and even better in some situations. Additionally, model accuracy was greatly influenced by the values of phenology parameters in validation.

关键词： parameter estimation frequentist method bayesian method crop model calibration