Robust filtering for discrete time piecewise impulsive systems

This paper investigates the filtering problems for the discrete time piecewise impulsive system. First, the robust H_∞ filtering problem and generalized H₂ filtering problem for the discrete time piecewise impulsive system are introduced. Then, linear matrix inequality (LMI) conditions are proposed for the design of H_∞ and generalized H₂ filters such that the resulting discrete time piecewise impulsive filtering error system is globally stable with guaranteed H_∞ or H₂ performance. Finally, a numerical simulation is also given to illustrate the effectiveness of the proposed approaches.     

VLSI电源网络近似电路模型研究

针对基于底层规划的电源网络分析、优化需求,提出了一种电源网络近似电路模型.根据电源网络结构特点,对其进行层次划分,并充分考虑标准单元吸纳电流的统计分布特性,建立各组成元件的电路模型.在此基础上,利用诺顿等效原理对其进行简化.实验表明,基于近似电路模型的电源网络分析结果比悲观分析要小38.75%(最差电压降)和36.04%(中心节点电压降),分析结果更为可信.     

基于时间估计的动态频谱接入算法

基于先验知识模型,设计了基于信道剩余空闲时间估计的动态频谱接入算法：每个次用户根据感知历史维护信道剩余空闲时间的估计向量并周期进行更新,每个时隙开始时次用户选择剩余空闲时间估计最大的信道接入。对动态频谱接入算法的适应性问题进行了分析,并求得了次用户的最优传输时间长度。仿真结果表明,在给定的参数下,新算法的信道利用率比其他算法提高约5%-10%,同时对主用户的干扰保持最低。     

电饭煲节电清洁附加器的研究和制作

该文通过设计的电饭煲外置附加器,来实现电饭煲的更多功能。解决了目前在大多数家庭中使用的普及型电饭煲存在功能单一和食物汤水外溢的问题。电饭煲外置节电装置通过温度传感器采集电饭煲出气孔的温度,遵照食物先大火后小火的烹调原则:烧稀饭或其他需要焖烧的食物时全功率加热至100℃,自动转低电压煲;烧干饭时全功率加热至100℃自动关闭,延时5min后通电把饭烧好,电饭煲内的米汤不会外溢出来,具有既节电又清洁卫生及操作方便等优点。     

一种基于遗传算法的自适应参数型多径时延估计

基于四阶累积量的自适应参数型多径时延估计（FOC—APMTDE）算法只能直接估计整数倍采样间隔的时延,为了克服此缺点,引入遗传算法进行时延估计的寻优,保留了FOC—APMTDE算法良好的抑制相关或非相关高斯噪声的性能,在低信噪比的情况下可以准确地直接估计非整数倍采样间隔的时延。计算机仿真试验验证了新方法的有效性。     

Comparative evaluation of software for retention time alignment of gas chromatography/time-of-flight mass spectrometry-based metabonomic data

In chromatography-based metabonomic research, retention time (RT) alignment of chromatographic peaks poses a challenge for the accurate profiling of biomarkers. Although a number of RT alignment software has been reported, the performance of these software packages have not been comprehensively evaluated. This study aimed to evaluate the RT alignment accuracy of publicly available and commercial RT alignment software. Two gas chromatography/mass spectrometry (GC/MS) datasets acquired from a mixture of standard metabolites and human bladder cancer urine samples, were used to assess three publicly available software packages, MetAlign, MZmine and TagFinder, and two commercial applications comprising the Calibration feature and Statistical Compare of ChromaTOF software. The overall RT alignment accuracies in aligning standard compounds mixture were 93, 92, 74, 73 and 42% for Calibration feature, MZmine, MetAlign, Statistical Compare and TagFinder, respectively. Additionally, unique trends were observed for the individual software with regards to the different experimental conditions related to extent and direction of RT shifts. Conflicting performance was observed for human urine samples suggesting that RT misalignments still occurred despite the use of RT alignment software. While RT alignment remains an inevitable step in data preprocessing, metabonomic researchers are recommended to perform manual check on the RT alignment of important biomarkers as part of their validation process.     

Synthesis and morphology of nanosized zeolite L

AFM is a powerful tool for imaging nanoscale surface features; it provides two and three dimensional crystal structure images and other information about actual surface of zeolite crystallites. In this paper, nanosized zeolite L is synthesized in different crystallization times and a study of crystal growth of zeolite L is reported using atomic force microscopy (AFM). X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) techniques are used for characterization of the as synthesized samples. TEM and two‐dimensional AFM images indicate that the zeolite particles are in a nano‐range and they have hexagonal structure. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

非Lipschitz条件Hilbert空间上扩散过程的短时间大偏差原理

Under the non-Lipschitzian condition, a small time large deviation principle of diffusion processes on Hilbert spaces is established. The operator theory and Gronwall inequality play an important role.     

GPU accelerated CESE method for 1D shock tube problems

In the present study, a GPU accelerated 1D space–time CESE method is developed and applied to shock tube problems with and without condensation. We have demonstrated how to implement the CESE algorithm to solve 1D shock tube problems using an older generation GPU (the NVIDIA 9800 GT) with relatively limited memory. To optimize the code performance, we used Shared Memory and solved the inter-Block boundary problem in two ways, namely the branch scheme and the overlapping scheme. The implementations of these schemes are discussed in detail and their performances are compared for the Sod shock tube problems. For the Sod problem without condensation, the speedup over an Intel CPU E7300 is 23 for the branch scheme and 41 for the overlapping scheme, respectively. While for problems with condensation, both schemes achieve higher acceleration ratios, 53 and 71, respectively. The higher speedup of the condensation case can be ascribed to the source term calculation which has a local dependence on the mesh point and the SOURCE kernel has a higher acceleration ratio.     

Carrier relaxation dynamics in InAs/InGaAlAs quantum dashes

We characterize size-dependent carrier relaxation dynamics of partial laser structures containing quantum dashes by time-resolved degenerate four wave mixing between 1.2 and 1.6 μm.