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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

bayesian method Reliability of Flight Simulator

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International English Education Research 2017年第1期 76-78页

作者： WANG Li XIONG Jing Shanghai University of Engineering Science Shanghai 201620 China

This paper introduces the basic viewpoints and characteristics of bayesian statistics. Which provides a theoretical basis for solving the problem of small sample of flight simulator using bayesian method. A series of formulas were derived to establish the bayesian reliability modeling and evaluation model for flight simulation equipment. The two key problems of bayesian method were pointed out as follows： obtaining the prior distribution of WeibuU parameter, calculating the parameter a posterior distribution and parameter estimation without analytic solution, and proposing the corresponding solution scheme.

关键词： Small sample data Flight simulation equipment Reliability modeling bayesian method Weibull parameter

A Reliability Improvement Predictive Approach to Software Testing with bayesian method

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A Reliability Improvement Predictive Approach to Software Te...

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

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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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

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

Packet Cache-Forward method Based on Improved bayesian Outlier Detection for Mobile Handover in Satellite Networks

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China Communications 2016年第6期13卷 167-177页

作者： Hefei Hu Dongming Yuan Mingxia Liao Yuan'an Liu School of Information and Communication Engineering Beijing University of Posts and Telecommunications School of Electronic Engineering Beijing University of Posts and Telecommunications

In this paper, we propose a Packet Cache-Forward(PCF) method based on improved bayesian outlier detection to eliminate out-of-order packets caused by transmission path drastically degradation during handover events in the moving satellite networks, for improving the performance of TCP. The proposed method uses an access node satellite to cache all received packets in a short time when handover occurs and forward them out in order. To calculate the cache time accurately, this paper establishes the bayesian based mixture model for detecting delay outliers of the entire handover scheme. In view of the outliers' misjudgment, an updated classification threshold and the sliding window has been suggested to correct category collections and model parameters for the purpose of quickly identifying exact compensation delay in the varied network load statuses. Simulation shows that, comparing to average processing delay detection method, the average accuracy rate was scaled up by about 4.0%, and there is about 5.5% cut in error rate in the meantime. It also behaves well even though testing with big dataset. Benefiting from the advantage of the proposed scheme in terms of performance, comparing to conventional independent handover and network controlled synchronizedhandover in simulated LEO satellite networks, the proposed independent handover with PCF eliminates packet out-of-order issue to get better improvement on congestion window. Eventually the average delay decreases more than 70% and TCP performance has improved more than 300%.

关键词： satellite networks handover bayesian method outlier detection

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)