Fault-Tolerant Control for Markovian Jump Delay Systems with an Adaptive Observer Approach

This paper investigates the problem of fault estimation and fault-tolerant control for a class of Markovian jump systems with mode-dependent interval time-varying delay and Lipschitz nonlinearities. In this paper, a new adaptive fault observer is designed to solve the problem of fault estimation. The proposed observer can estimate the states and faults simultaneously, whether faults are of time-varying or constant characterization. Based on the fault estimation, a fault-tolerant controller is designed to stabilize the closed-loop system. Sufficient conditions for the existence of the observer gain and fault-tolerant controller gain are got by a set of linear matrix inequalities. Finally, a numerical example is presented to illustrate the effectiveness of the proposed fault-tolerant control method.     

Design and Experimental Demonstration of Cherenkov Radiation Source Based on Metallic Photonic Crystal Slow Wave Structure

This paper presents a kind of Cherenkov radiation source based on metallic photonic crystal (MPC) slow-wave structure (SWS) cavity. The Cherenkov source designed by linear theory works at 34.7 GHz when the cathode voltage is 550 kV. The three-dimensional particle-in-cell (PIC) simulation of the SWS shows the operating frequency of 35.56 GHz with a single TM₀₁ mode is basically consistent with the theoretically one under the same parameters. An experiment was implemented to testify the results of theory and PIC simulation. The experimental system includes a cathode emitting unit, the SWS, a magnetic system, an output antenna, and detectors. Experimental results show that the operating frequency through detecting the retarded time of wave propagation in waveguides is around 35.5 GHz with a single TM₀₁ mode and an output power reaching 54 MW. It indicates that the MPC structure can reduce mode competition. The purpose of the paper is to show in theory and in preliminary experiment that a SWS with PBG can produce microwaves in TM₀₁ mode. But it still provides a good experimental and theoretical foundation for designing high-power microwave devices.     

粗糙海面的电磁散射缩比模拟测量的若干基本问题

针对实验室内难以构造的高海情PM谱海面,采用电磁缩比测量的方法研究其电磁散射特性,首先定量分析了以淡水替代海水造成不满足物理相似性要求而引入的误差,然后讨论了缩比PM谱海面满足几何相似性条件的要求,和对粗糙海面进行缩比模拟测量的途径,根据粗糙海面缩比模拟理论与条件,在实验室内成功模拟构造满足缩比测量理论的粗糙海面。     

固态继电器输入端电磁脉冲效应研究

通过方波电流注入方法对某型号固态继电器的输入端电磁脉冲效应进行了实验研究,给出了输入端方波注入对固态继电器输出端性能影响的实验结果,为固态继电器的产品设计及实际应用提供参考。     

The design of spin filter junction in zigzag graphene nanoribbons with asymmetric edge hydrogenation

Using the non-equilibrium Green’s function method combined with the density functional theory, we investigate the electronic transport properties of a heterostructure based on zigzag graphene, This heterostructure consists of H2–NZGNR–H and H–NZGNR–H. Results show that a perfect dual spin filtering effect can be realized with the parallel (P) and antiparallel (AP) magnetiesm configuration, and some magnetic domain walls (DW) at the interface between two component ribbons. The magnetic moments, DOS and PDOS, the transmission pathways and LDOS demonstrate that the edge of C–H2 bonds have important effects for magnetic and spin dependent transport properties compared to the edge of C–H bonds. Our results show that the H2–ZGNR–H/H–NZGNR–H heterostructure holds promise for magneto electronics devices which can keep steady properties when change the widths of the two component ribbons.     

核电站辅助过滤器壳体设计

以开发出适合我国压水堆核电站的辅助过滤器来代替进口产品为背景,以核电站蒸汽发生器排污系统中过滤器壳体为设计对象,按照常规设计法,遵循GB150．2011,对过滤器壳体依次进行了筒体、封头、进出水接管及壳体开孔补强和法兰密封设计。最后将所设计的壳体导入有限元分析软件ANSYS11．0进行强度验证,结果表明其强度满足要求。     

基于AMBE-1000与nRF401的无线语音传输系统的实现

介绍了Digital Voice System. Inc公司的AMBE-1000芯片与挪威Nordic 公司的nRF401芯片的特点与工作原理,给出了一种基于AMBE-1000和nRF401的无线语音传输系统的实现.系统采用AMBE-1000 结合TCM320AC36C进行语音信号的处理;同时,采用nRF401传输数字化后的语音信号;在整体上,采用AT89C52 处理器负责接口之间的数据处理.提出了系统的硬件设计、软件流程.此系统具有无需许可证、功耗低、使用方便等特点,可广泛应用于无线语音传输系统的产品设计中.     

Tracking myocardial motion from cine DENSE images using spatiotemporal phase unwrapping and temporal fitting

Displacement encoding with stimulated echoes (DENSE) encodes myocardial tissue displacement into the phase of the MR image. Cine DENSE allows for rapid quantification of myocardial displacement at multiple cardiac phases through the majority of the cardiac cycle. For practical sensitivities to motion, relatively high displacement encoding frequencies are used and phase wrapping typically occurs. In order to obtain absolute measures of displacement, a two-dimensional (2-D) quality-guided phase unwrapping algorithm was adapted to unwrap both spatially and temporally. Both a fully automated algorithm and a faster semi-automated algorithm are proposed. A method for computing the 2-D trajectories of discrete points in the myocardium as they move through the cardiac cycle is introduced. The error in individual displacement measurements is reduced by fitting a time series to sequential displacement measurements along each trajectory. This improvement is in turn reflected in strain maps, which are derived directly from the trajectories. These methods were validated both in vivo and on a rotating phantom. Further measurements were made to optimize the displacement encoding frequency and to estimate the baseline strain noise both on the phantom and in vivo. The fully automated phase unwrapping algorithm was successful for 767 out of 800 images (95.9%), and the semi-automated algorithm was successful for 786 out of 800 images (98.3%). The accuracy of the tracking algorithm for typical cardiac displacements on a rotating phantom is 0.24 +/- 0.15 mm. The optimal displacement encoding frequency is in the region of 0.1 cycles/mm, and, for 2 scans of 17-s duration, the strain noise after temporal fitting was estimated to be 2.5 +/- 3.0% at end-diastole, 3.1 +/- 3.1% at end-systole, and 5.3 +/- 5.0% in mid-diastole. The improvement in intra-myocardial strain measurements due to temporal fitting is apparent in strain histograms, and also in identifying regions of dysfunctional myocardium in studies of patients with infarcts.     

Preservation of Conditionally Nonblocking Switches Under Two-Stage Interconnection

The two-stage interconnection network is conceivably the most compact design for interconnecting small switches into a large switch. Switches so constructed typically can be controlled in the self-routing manner, because the route from an input to an output is unique. Different orderings of network input/output result in different versions of the two-stage interconnection network, two of which are known to preserve various classes of conditionally nonblocking switches. This paper adds Latin-square switches, rotators, reflectors, twisters, and untwisters to this set of classes with applications in load balancing, crosstalk-free optical switching, full connectivity among multiple users, etc. Knowledge of switch preservation under a certain style of multistage interconnection not only allows recursive construction of indefinitely large switches, but also provides insight, generality, and algorithmic flexibility in the construction     

中兴通讯CDMA2000 ALL-IP灵活的组网解决方案

CDMA2000 ALL-IP产品推出了包含Ap接口在内的ALL-IP接口解决方案,丰富了网络架构.中兴通讯CDMA2000 ALL-IP产品技术先进,容量大,接口协议丰富,具有兼容性和演进性.描述了中兴通讯CDMA2000ALL-IP网络灵活的组网方案,主要针对CDMA网络演进到LMSD阶段后,分析实现BSC与核心网之间A接口分组传输后带来的一系列网络架构优势,组网方式的灵活.