基于自适应逐步Ⅱ型混合截尾试验Burr-Ⅻ分布的统计分析

本文分别基于自适应逐步Ⅱ型混合截尾试验和逐步Ⅱ型混合截尾试验,结合部分步进应力加速寿命试验,使用经典统计理论和Bayes理论讨论了Burr-Ⅻ分布下的统计分析问题.给出了Burr-Ⅻ分布在不同截尾试验下的极大似然估计和Bayes估计.利用Monte-Carlo模拟对自适应逐步Ⅱ型混合截尾试验和逐步Ⅱ型混合截尾试验下的参数估计进行模拟比较.结果表明,自适应逐步Ⅱ型混合截尾试验下的均方误差更小,区间长度更短,相对误差更小,所以自适应逐步Ⅱ型混合截尾试验更优越.     

Some interval-valued intuitionistic uncertain linguistic hybrid Shapley operators

Two interval-valued intuitionistic uncertain linguistic hybrid operators cal ed the induced interval-valued intuitionistic uncertain linguistic hybrid Shapley averaging （I-IIULHSA） operator and the induced interval-valued intuitionistic uncertain linguistic hybrid Shapley geometric （I-IIULHSG） operator are defined. These operators not only reflect the importance of elements and their ordered positions, but also consider the correlations among elements and their ordered positions. Since the fuzzy measures are defined on the power set, it makes the problem exponentially complex. In order to simplify the complexity of solving a fuzzy measure, we further define the induced interval-valued intuitionistic uncertain linguistic hybrid λ-Shapley averaging （I-IIULHλSA） operator and the induced interval-valued intuitionistic uncertain linguistic hybrid λ-Shapley geometric （I-IIULHλSG） operator. Moreover, an approach for multi-attribute group decision making under the interval-valued intuitionistic uncertain linguistic environment is developed. Finally, a numerical example is provided to verify the developed procedure and demonstrate its practicality and feasibility.     

Inference for constant-stress accelerated life test with Type-I progressively hybrid censored data from Burr-Xll distribution

This paper proposes a simple constant-stress accel- erated life test （ALT） model from Burr type XII distribution when the data are Type-I progressively hybrid censored. The maximum likelihood estimation （MLE） of the parameters is obtained through the numerical method for solving the likelihood equations. Approxi- mate confidence interval （CI）, based on normal approximation to the asymptotic distribution of MLE and percentile bootstrap Cl is derived. Finally, a numerical example is introduced and then a Monte Carlo simulation study is carried out to illustrate the pro- posed method.     

Improved algorithms to plan missions for agile earth observation satellites

This study concentrates of the new generation of the agile （AEOS）. AEOS is a key study object on management problems earth observation satellite in many countries because of its many advantages over non-agile satellites. Hence, the mission planning and scheduling of AEOS is a popular research problem. This research investigates AEOS characteristics and establishes a mission planning model based on the working principle and constraints of AEOS as per analysis. To solve the scheduling issue of AEOS, several improved algorithms are developed. Simulation results suggest that these algorithms are effective.     

竞争失效场合相似产品可靠性的综合评估

对小样本情形下的联合Ⅱ型截尾寿命试验进行综合分析.针对产品可能存在多种失效模式问题,建立试验数据服从独立指数分布的竞争失效模型.基于极大似然估计,利用条件矩母函数导出参数的精确分布,据此构造参数的精确置信区间.并采用Bootstrap方法给出参数的区间估计.最后,通过Monte-Carlo仿真比较估计的优良性,利用数值算例验证了本文方法的有效性和可行性.     

Statistical Inference for a Simple Step Stress Model with Competing Risks Based on Generalized Type-Ⅰ Hybrid Censoring

This paper investigates a simple step-stress accelerated lifetime test(SSALT) model for the inferential analysis of exponential competing risks data. A generalized type-I hybrid censoring scheme is employed to improve the efficiency and controllability of the test. Firstly, the MLEs for parameters are established based on the cumulative exposure model(CEM). Then the conditional moment generating function(MGF) for unknown parameters is set up using conditional expectation and multiple integral techniques. Thirdly, confidence intervals(CIs) are constructed by the exact MGF-based method, the approximate normality-based method, and the bias-corrected and accelerated(BCa) percentile bootstrap method. Finally, we present simulation studies and an illustrative example to compare the performances of different methods.     

Exponential Stability of a Reparable System with Two Types of Repair Facilities

The exponential stability of a reparable system with two types of repair facilities is discussed in this paper. We present that the c0-semigroup generated by the system operator is quasi-compact and irreducible. It is known that 0 is a simple eigenvalue of the system operator. In combination with this, we obtain that the time-dependent solution exponentially converges to the steady-state solution, which is the positive eigenfuction corresponding to the simple eigenvalue 0.     

含屏蔽数据四单元混联系统的可靠性分析

讨论了两种含屏蔽数据四单元混联系统的可靠性分析问题。在单元失效率为指数函数的情形下,详细推导出两种混联系统在逐步Ⅱ型混合截尾试验下的似然函数。利用极大似然方法给出了单元分布参数及系统可靠度函数的极大似然估计,采用似然比方法构造了未知参数的近似置信区间。最后运用蒙特卡罗方法进行随机模拟,验证了所提方法的正确性和有效性。     

相似产品步进应力加速寿命试验的统计分析

本文将单组样本的步进应力加速寿命试验(SSALT)拓展到双样本情形.基于累积失效模型(CEM),对两组指数产品的联合Ⅱ型截尾数据进行综合分析.首先,计算未知参数的极大似然估计(MLE),并利用矩母函数(MGF)建立其条件概率分布.然后,采用两种方法,基于概率分布的精确分析方法和参数的Bootstrap方法,构建参数的置信区间(CIs).以覆盖率作为评价标准,对两种方法的区间估计效果进行分析.最后,通过数值算例验证了本文方法的有效性.     

Evidence fusion procedure based on hybrid DSm model

Dezert-Smarandache（DSm） theory, a new information fusion theory, is widely applied in image processing, multiple targets tracking identification, and other areas for its excellent processing ability of imperfect information. However, earlier research on DSm theory mainly focused on one sort of questions. An evidence fusion procedure is proposed based on the hybrid DSm model to compensate for a lack of research on the entire information procedure of DSm theory. This paper analyzes the evidence fusion procedure, as well as correlative node input and output information. Key steps and detailed procedures of evidence fusion are also discussed. Finally, an experiment illustrates the efficiency of the proposed evidence fusion procedure.     

基于竞争失效数据的Lindley分布参数估计

假定产品在使用时经历多种竞争失效,每种失效寿命数据服从Lindley分布。竞争失效数据包括不完全数据和截尾数据。对竞争失效分布进行参数点估计、相对风险率计算,讨论了参数的渐进置信区间和Bootstrap置信区间。为考察其适应性,一组实际数据用来说明各种参数估计方法的使用情况,同时,分别用指数分布和威布尔分布拟合该组数据,并计算相应的统计量。结果表明,根据3种分布的极大似然估计量和K-S值,Lindley分布对该组数据具有最好的适应性。     

A statistical inference for generalized Rayleigh model under Type-Ⅱ progressive censoring with binomial removals

This paper considers the parameters and reliability characteristics estimation problem of the generalized Rayleigh distribution under progressively Type-Ⅱ censoring with random removals,that is,the number of units removed at each failure time follows the binomial distribution.The maximum likelihood estimation and the Bayesian estimation are derived.In the meanwhile,through a great quantity of Monte Carlo simulation experiments we have studied different hyperparameters as well as symmetric and asymmetric loss functions in the Bayesian estimation procedure.A real industrial case is presented to justify and illustrate the proposed methods.We also investigate the expected experimentation time and discuss the influence of the parameters on the termination point to complete the censoring test.     

WHO WON THE 2008 OLYMPICS？ A MULTICRITERIA DECISION OF MEASURING INTANGIBLES

It often happens that at the end of Olympics games the medals won by more than one country are many and close in total number as in the 2008 games where China won 100 medals with many gold ones and the United States won 110 medals but with a lesser number of gold medals. The question is： Although it is often done arbitrarily, is there a way to quantify the values of gold, silver and bronze medals legitimately to resolve this concern？ This short exposition shows that there is by using the author＇s theory for the measurement of intangibles, the Analytic Hierarchy Process.     

Asymptotic and stable proper ties of general stochastic functional differential equations

The asymptotic and stable properties of general stochastic functional differential equations are investigated by the multiple Lyapunov function method, which admits non-negative up-per bounds for the stochastic derivatives of the Lyapunov functions, a theorem for asymptotic properties of the LaSal e-type described by limit sets of the solutions of the equations is obtained. Based on the asymptotic properties to the limit set, a theorem of asymptotic stability of the stochastic functional differential equations is also established, which enables us to construct the Lyapunov functions more easily in application. Particularly, the wel-known classical theorem on stochastic stability is a special case of our result, the operator LV is not required to be negative which is more general to fulfil and the stochastic perturbation plays an important role in it. These show clearly the improvement of the traditional method to find the Lyapunov functions. A numerical simulation example is given to il ustrate the usage of the method.     

Interactive multigraph visualization and exploration with a two-phase strategy

While it is very reasonable to use a multigraph consisting of multiple edges between vertices to represent various relationships, the multigraph has not drawn much attention in research. To visualize such a multigraph, a clear layout representing a global structure is of great importance, and interactive visual analysis which allows the multiple edges to be adjusted in appropriate ways for detailed presentation is also essential. A novel interactive two-phase approach to visualizing and exploring multigraph is proposed. The approach consists of two phases： the first phase improves the previous popular works on force-directed methods to produce a brief drawing for the aggregation graph of the input multigraph, while the second phase proposes two interactive strategies, the magnifier model and the thematic-oriented subgraph model. The former highlights the internal details of an aggregation edge which is selected interactively by user, and draws the details in a magnifying view by cubic Bezier curves; the latter highlights only the thematic subgraph consisting of the selected multiple edges that the user concerns. The efficiency of the proposed approach is demonstrated with a real-world multigraph dataset and how it is used effectively is discussed for various potential applications.     

Adaptive actuator failure compensation and disturbance rejection scheme for spacecraft

An adaptive actuator failure compensation scheme is proposed for attitude tracking control of spacecraft with unknown disturbances and uncertain actuator failures. A new feature of this adaptive control scheme is the adaptation of the failure pattern parameter estimates, as well as the failure signal parameter estimates, for direct adaptive actuator failure compensation. Based on an adaptive backstepping control design, the estimates of the disturbance parameters are used to solve the disturbance rejection problem. The unknown disturbances are compensated completely with the stability of the whole closed-loop system. The scheme is not only able to accommodate uncertain actuator failures, but also robust against unknown external disturbances. Simulation results verify the desired adaptive actuator failure compensation performance.     

Spectral analysis and stabilization of a coupled wave-ODE system

In this paper, an interconnected wave-ODE system with K-V damping in the wave equation and unknown parameters in the ODE is considered. It is found that the spectrum of the system operator is composed of two parts： Point spectrum and continuous spectrum. The continuous spectrum consists of an isolated point 1 1/d, and there are two branches of the asymptotic eigenvalues： The first branch is accumulating towards 1 -2, and the other branch tends to -∞. It is shown that there is a sequence of generalized eigenfunctions, which forms a Riesz basis for the Hilbert state space. As a consequence, the spectrum-determined growth condition and exponential stability of the system are concluded.     

双应力恒加寿命试验下相依竞争失效模型的统计分析

针对传统加速寿命试验仅考虑单一应力且假定产品各失效机理之间独立的问题,首先结合自适应逐步Ⅱ型混合截尾(adaptive type-Ⅱ progressively hybrid censored scheme, AT-Ⅱ PHCS)寿命试验,建立AT-Ⅱ PHCS双应力恒加寿命试验。其次,利用Marshall-Olkin二维Gompertz (Marshall-Olkin bivariate Gompertz, MOBG)分布构建产品失效机理间相依关系。然后,基于AT-Ⅱ PHCS双应力加速寿命试验下相依竞争失效数据,利用极大似然理论,计算了参数的极大似然估计(maximum likelihood estimation, MLE),采用渐近似然理论和Bootstrap抽样方法构建参数的置信区间(confidence interval, CI)。最后,结合一个实例对构建的相依竞争失效模型进行了算例验证,结果表明其具有很好的统计推断性能。     

双应力恒加寿命试验下相依竞争失效模型的统计分析

针对传统加速寿命试验仅考虑单一应力且假定产品各失效机理之间独立的问题,首先结合自适应逐步Ⅱ型混合截尾(adaptive type-Ⅱ progressively hybrid censored scheme, AT-Ⅱ PHCS)寿命试验,建立AT-Ⅱ PHCS双应力恒加寿命试验。其次,利用Marshall-Olkin二维Gompertz (Marshall-Olkin bivariate Gompertz, MOBG)分布构建产品失效机理间相依关系。然后,基于AT-Ⅱ PHCS双应力加速寿命试验下相依竞争失效数据,利用极大似然理论,计算了参数的极大似然估计(maximum likelihood estimation, MLE),采用渐近似然理论和Bootstrap抽样方法构建参数的置信区间(confidence interval, CI)。最后,结合一个实例对构建的相依竞争失效模型进行了算例验证,结果表明其具有很好的统计推断性能。     

Robust bounded control for uncertain flight dynamics using disturbance observer

The robust bounded flight control scheme is developed for the uncertain longitudinal flight dynamics of the fighter with control input saturation invoking the backstepping technique. To enhance the disturbance rejection ability of the robust flight control for fighters, the sliding mode disturbance observer is designed to estimate the compounded disturbance including the unknown external disturbance and the effect of the control input saturation. Based on the backstepping technique and the compounded disturbance estimated output, the robust bounded flight control scheme is proposed for the fighter with the unknown external disturbance and the control input saturation. The closed-loop system stability under the developed robust bounded flight control scheme is rigorously proved using the Lyapunov method and the uniformly asymptotical convergences of all closed-loop signals are guaranteed. Finally, simulation results are presented to show the effectiveness of the proposed robust bounded flight control scheme for the uncertain longitudinal flight dynamics of the fighter.