A new family of covariate-adjusted response adaptive designs and their properties

It is often important to incorporate covariate information in the design of clinical trials. In literature there are many designs of using stratification and covariate-adaptive randomization to balance certain known covariate. Recently, some covariate-adjusted response-adaptive （CARA） designs have been proposed and their asymptotic properties have been studied （Ann. Statist. 2007）. However, these CARA designs usually have high variabilities. In this paper, a new family of covariate-adjusted response-adaptive （CARA） designs is presented. It is shown that the new designs have less variables and therefore are more efficient.     

业务载荷自适应动态资源调度

通过对WEB应用负荷与现有WEB服务器体系结构不相适应的问题分析和研究,提出了基于业务载荷的自适应动态资源调度.首先从互联网24小时载荷变化分析现有WEB服务系统能效比较低的原因,然后介绍了基于认知的主动重构WEB服务以及动态资源调度所需参数及感知方法,并基于此提出了负荷预测和自适应动态资源调度算法,最后通过实验验证了算法的有效性.     

ERS-1/2 InSAR干涉图处理的滤波方法实验对比研究

选择合适的滤波方法对InSar干涉相位图进行滤波处理是提高干涉图质量的关键技术环节．系统研究了圆周期均值滤波、圆周期中值滤波、加权圆周期滤波和基于梯度的自适应滤波方法，利用ERS-1／2数据进行了对比实验，并对各方法的效果进行了评价．结果表明，基于梯度的自适应滤波方法可以取得稳定效果，而梯度的自适应滤波与圆周期中值滤波组合效果更加显著．     

Robust iris biometric system for visible wavelength data

Commercial iris biometric systems exhibit good performance for near-infrared(NIR) images but poor performance for visible wavelength(VW) data.To address this problem,we propose an iris biometric system for VW data.The system includes localizing iris boundaries that use bimodal thresholding,Euclidean distance transform(EDT),and a circular pixel counting scheme(CPCS).Eyelids are localized using a parabolic pixel counting scheme(PPCS),and eyelashes,light reflections,and skin parts are adaptively detected using image intensity.Features are extracted using the log Gabor filter,and finally,matching is performed using Hamming distance(HD).The experimental results on UBIRIS and CASIA show that the proposed technique outperforms contemporary approaches.     

改进的MEMS陀螺随机噪声自适应Kalman实时滤波方法

针对微机电系统陀螺易受环境影响和稳定性能较差,导致建立的随机漂移模型参数和随机噪声统计特性变化的问题,提出了一种改进的指数渐消记忆自适应Kalman实时滤波方法。通过分析实测数据确定随机漂移自回归滑动平均模型阶数,在此基础上利用递推最小二乘法对模型参数进行实时更新。根据陀螺噪声参数特点,提出了基于渐消记忆因子的Allan方差分析法和Sage-Husa自适应滤波算法同时对Q和R进行参数估计的实时滤波方法,避免了系统状态估计和量测噪声参数估计的相互耦合和制约。实验结果表明:相比标准Kalman滤波补偿方法及传统的固定Q阵只对R阵做自适应估计的滤波方法,本文方法能够更加有效地对MEMS陀螺随机漂移误差进行实时补偿,具有较好的适应性和稳定性。     

不同目标函数的量子系统动态跟踪

针对不同的随时间变化的目标函数,对所给定的封闭量子系统,利用李雅普诺夫稳定性定理进行控制律的设计.对于系统跟踪过程中控制量过大的问题,通过采用自适应算法来加以解决.分别针对不同的目标函数进行了系统仿真实验.在所设计的控制律的作用下,能够使控制系统的输出从任意初态动态跟踪目标系统的状态.仿真实验验证了所提出的控制策略具有根据系统响应过程中出现的控制值过大的情况自适应地调整控制律、对动态目标系统实时跟踪的能力,同时对不同的目标函数具有通用的特性.     

自适应演化硬件系统中遗传算法内核设计

根据基于演化的自适应系统的体系架构,将与具体应用相对独立的遗传算法操作部分取出来,结合算法的操作流程,设计了一个与应用无关的、能够独立完成遗传算法操作的GAK(遗传算法内核).采用VHDL(超高速集成电路硬件描述语言)语言描述的状态机来实现该设计,其中种群规模、染色体长度等参数均可配置.采用Xilinx的Vl000FG680、速度等级为-6的EPGA(现场可编程门阵列)来实现GAK,其中染色体长度为8位、适应度值为16位、种群规模为256,此时该设计的综合结果为:占用资源为485个片(Slice),时钟频率为48.51MH.进而在GAK上仿真求解了多项式函数的极值优化问题，从而验证了设计的有效性.     

Multi-rate sensor fusion-based adaptive discrete finite-time synergetic control for flexible-joint mechanical systems

This paper proposes an adaptive discrete finite-time synergetic control （ADFTSC） scheme based on a multi-rate sensor fusion estimator for flexible-joint mechanical systems in the presence of unmeasured states and dynamic uncertainties. Multi-rate sensors are employed to observe the system states which cannot be directly obtained by encoders due to the existence of joint flexibilities. By using an extended Kalman filter （EKF）, the finite-time synergetic controller is designed based on a sensor fusion estimator which estimates states and parameters of the mechanical system with multi-rate measurements. The proposed controller can guarantee the finite-time convergence of tracking errors by the theoretical derivation. Simulation and experimental studies are included to validate the effectiveness of the proposed approach.