For a general linear mixed model with two variance components, a set of simple conditions is obtained, under which, (i) the least squares estimate of the fixed effects and the analysis of variance (ANOVA) estimates of...For a general linear mixed model with two variance components, a set of simple conditions is obtained, under which, (i) the least squares estimate of the fixed effects and the analysis of variance (ANOVA) estimates of variance components are proved to be uniformly minimum variance unbiased estimates simultaneously; (ii) the exact confidence intervals of the fixed effects and uniformly optimal unbiased tests on variance components are given; (iii) the exact probability expression of ANOVA estimates of variance components taking negative value is obtained.展开更多
Problems of the simultaneous optimal estimates and the optimal tests in general mixed models are considered. A necessary and sufficient condition is presented for the least squares estimate of the fixed effects and th...Problems of the simultaneous optimal estimates and the optimal tests in general mixed models are considered. A necessary and sufficient condition is presented for the least squares estimate of the fixed effects and the analysis of variance （Hendreson III＇s） estimate of variance components being uniformly minimum variance unbiased estimates simultaneously. This result can be applied to the problems of finding uniformly optimal unbiased tests and uniformly most accurate unbiased confidential interval on parameters of interest, and for finding equivalences of several common estimates of variance components.展开更多
针对传统三步迭代滤波算法在遭受网络攻击的情况下无法对系统状态进行估计的问题,提出一种扩展三步递归滤波算法,可以对遭受混合网络攻击的网络化系统进行状态估计。分别将拒绝服务(Denial of Service,DoS)攻击建模为服从Bernoulli分布...针对传统三步迭代滤波算法在遭受网络攻击的情况下无法对系统状态进行估计的问题,提出一种扩展三步递归滤波算法,可以对遭受混合网络攻击的网络化系统进行状态估计。分别将拒绝服务(Denial of Service,DoS)攻击建模为服从Bernoulli分布的随机变量,将虚假数据注入(False Data Injection,FDI)攻击描述为未知干扰输入项,对混合网络攻击下网络化系统的状态进行估计。通过设计新息对测量方程中的攻击信号进行估计,使用此估计值进一步修正新息,以便对系统状态进行估计。然后采用矩阵增广方式将状态方程中的攻击信号增广入系统状态值,继续设计新息对增广后的状态进行估计,此时可同时得到系统状态和2个攻击信号的估计值,且为最小方差无偏估计值。最后,使用数值仿真和无人机飞行模型仿真验证了滤波算法的有效性。展开更多
Opting to follow the computing-design philosophy that the best way to reduce power consumption and increase energy efficiency is to reduce waste, we propose an architecture with a very simple ready-implementation by u...Opting to follow the computing-design philosophy that the best way to reduce power consumption and increase energy efficiency is to reduce waste, we propose an architecture with a very simple ready-implementation by using an NComputing device that can allow multi-users but only one computer is needed. This intuitively can save energy, space as well as cost. In this paper, we propose a simple and realistic NComputing architecture to study the energy and power-efficient consumption of desktop computer systems by using the NComputing device. We also propose new approaches to estimate the reliability of k-out-of-n systems based on the delta method. The k-out-of-n system consisting of n subsystems works if and only if at least k-of-the-n subsystems work. More specificly, we develop approaches to obtain the reliability estimation for the k-out-of-n systems which is composed of n independent and identically distributed subsystems where each subsystem （or energy-efficient usage application） can be assumed to follow a two-parameter exponential lifetime distribution function. The detailed derivations of reliability estimation of k-out-of-n systems based on the biased-corrected estimator, known as delta method, the uniformly minimum variance unbiased estimate （UMVUE） and maximum likelihood estimate （MLE） are discussed. An energy-management NComputing application is discussed to illustrate the reliability results in terms of the energy consumption usages of a computer system with qua（t-core, 8 GB of RAM, and a GeForce 9800GX-2 graphics card to perform various complex applications. The estimated reliability values of systems based on the UMVUE and the delta method differ only slightly. Often the UMVUE of reliability for a complex system is a lot more difficult to obtain, if not impossible. The delta method seems to be a simple and better approach to obtain the reliability estimation of complex systems. The results of this study also show that, in practice, the NComputing architecture improves both energy cost sa展开更多
基金This work was partially supported by the National Natural Science Foundation of China(Grant No.10271010)the Natural Science Foundation of Beijing(Grant Mo.1032001).
文摘For a general linear mixed model with two variance components, a set of simple conditions is obtained, under which, (i) the least squares estimate of the fixed effects and the analysis of variance (ANOVA) estimates of variance components are proved to be uniformly minimum variance unbiased estimates simultaneously; (ii) the exact confidence intervals of the fixed effects and uniformly optimal unbiased tests on variance components are given; (iii) the exact probability expression of ANOVA estimates of variance components taking negative value is obtained.
基金Funding Project for Academic Human Resources Development in Institutions of Higher Learning under the Jurisdiction of Beijing Municipality PHR (IHLB)National Natural Science Foundation of China (NSFC) (10801005) and (NSFC) (10771010)the Intramural Research Program of the National Institute of Child Health and Human Development,National Institute of Health
文摘Problems of the simultaneous optimal estimates and the optimal tests in general mixed models are considered. A necessary and sufficient condition is presented for the least squares estimate of the fixed effects and the analysis of variance （Hendreson III＇s） estimate of variance components being uniformly minimum variance unbiased estimates simultaneously. This result can be applied to the problems of finding uniformly optimal unbiased tests and uniformly most accurate unbiased confidential interval on parameters of interest, and for finding equivalences of several common estimates of variance components.
文摘针对传统三步迭代滤波算法在遭受网络攻击的情况下无法对系统状态进行估计的问题,提出一种扩展三步递归滤波算法,可以对遭受混合网络攻击的网络化系统进行状态估计。分别将拒绝服务(Denial of Service,DoS)攻击建模为服从Bernoulli分布的随机变量,将虚假数据注入(False Data Injection,FDI)攻击描述为未知干扰输入项,对混合网络攻击下网络化系统的状态进行估计。通过设计新息对测量方程中的攻击信号进行估计,使用此估计值进一步修正新息,以便对系统状态进行估计。然后采用矩阵增广方式将状态方程中的攻击信号增广入系统状态值,继续设计新息对增广后的状态进行估计,此时可同时得到系统状态和2个攻击信号的估计值,且为最小方差无偏估计值。最后,使用数值仿真和无人机飞行模型仿真验证了滤波算法的有效性。
基金supported by Rutgers CCC Green Computing Initiative
文摘Opting to follow the computing-design philosophy that the best way to reduce power consumption and increase energy efficiency is to reduce waste, we propose an architecture with a very simple ready-implementation by using an NComputing device that can allow multi-users but only one computer is needed. This intuitively can save energy, space as well as cost. In this paper, we propose a simple and realistic NComputing architecture to study the energy and power-efficient consumption of desktop computer systems by using the NComputing device. We also propose new approaches to estimate the reliability of k-out-of-n systems based on the delta method. The k-out-of-n system consisting of n subsystems works if and only if at least k-of-the-n subsystems work. More specificly, we develop approaches to obtain the reliability estimation for the k-out-of-n systems which is composed of n independent and identically distributed subsystems where each subsystem （or energy-efficient usage application） can be assumed to follow a two-parameter exponential lifetime distribution function. The detailed derivations of reliability estimation of k-out-of-n systems based on the biased-corrected estimator, known as delta method, the uniformly minimum variance unbiased estimate （UMVUE） and maximum likelihood estimate （MLE） are discussed. An energy-management NComputing application is discussed to illustrate the reliability results in terms of the energy consumption usages of a computer system with qua（t-core, 8 GB of RAM, and a GeForce 9800GX-2 graphics card to perform various complex applications. The estimated reliability values of systems based on the UMVUE and the delta method differ only slightly. Often the UMVUE of reliability for a complex system is a lot more difficult to obtain, if not impossible. The delta method seems to be a simple and better approach to obtain the reliability estimation of complex systems. The results of this study also show that, in practice, the NComputing architecture improves both energy cost sa
