Stability analysis and antiwindup design of uncertain discrete-time switched linear systems subject to actuator saturation

This paper investigates the stability analysis and antiwindup design problem for a class of discrete-time switched linear systems with time-varying norm-bounded uncertainties and saturating actuators by using the switched Lyapunov function approach.Supposing that a set of linear dynamic output controllers have been designed to stabilize the switched system without considering its input saturation,we design antiwindup compensation gains in order to enlarge the domain of attraction of the closed-loop system in the presence of saturation.Then,in terms of a sector condition,the antiwindup compensation gains which aim to maximize the estimation of domain of attraction of the closed-loop system are presented by solving a convex optimization problem with linear matrix inequality(LMI)constraints.A numerical example is given to demonstrate the effectiveness of the proposed design method.     

A New Medical Image Enhancement Based on Human Visual Characteristics

Study of image enhancement shows that the quality of image heavily relies on human visual system. In this paper, we apply this fact effectively to design a new image enhancement method for medical images that improves the detail regions. First, the eye region of interest （ROI） is segmented; then the Un-sharp Masking （USM） is used to enhance the detail regions. Experiments show that the proposed method can effectively improve the accuracy of medical image enhancement and has a significant effect.     

MIS在人事和月票管理中的实践和应用

叙述了MIS在厦门市轮渡公司的人事和月票管理中的实践和应用。首先从系统的组成、基本原理、基本功能阐述了MIS在人事管理中的实践 ,并取得既方便又快捷、且准确的效果 ;然后通过对轮渡TM卡的构成、基本功能、应用效果进行了阐述 ,证明了TM卡最适用于轮渡作为月票使用。在当今社会 ,MIS已成为现代企业不可缺少的组成部分 ,是企业升级的重要标志。     

Evaluation of measurement uncertainty based on grey system theory for small samples from an unknown distribution

To evaluate measurement uncertainty for small sample size and measurement data from an unknown distribution, we propose a grey evaluation method of measurement uncertainty based on the grey relation coefficient. The uncertainty of measurement is analyzed using grey system theory, and the defects of the grey evaluation model of measurement uncertainty (GEMU) are studied. We then establish an improved grey evaluation model of measurement uncertainty (IGEMU). Simulations show that the precision of IGEMU is greater than that of GEMU, and that sample size has only a small effect on the precision of IGEVU. In particular, IGEMU is applied to evaluating measurement uncertainty for small sample size and measurement data from an unknown distribution. The measurement uncertainty of total profile deviation, which is measured by the CNC gear measuring center, can be evaluated by a combination of IGEMU and the Monte Carlo method.     

A Planar 4-Bit Reconfigurable Antenna Array Based on the Design Philosophy of Information MetasurfacesOA

Inspired by the design philosophy of information metasurfaces based on the digital coding concept,a planar 4-bit reconfigurable antenna array with low profile of 0.15λ₀(where λ₀ is the free-space wavelength)is presented.The array is based on a digital coding radiation element consisting of a 1-bit magnetoelectric(ME) dipole and a miniaturized reflection-type phase shifter(RTPS).The proposed 1-bit ME dipole can provide two digital states of "0" and "1"(with 0° and 180° phase...     

A high-precision and 10 bit two-step Time-to-Digital Converter for TOF application

A two-step high-precision Time-to-Digital Converter(TDC), integrated with a Single-Photon Avalanche Diode(SPAD), used for Time-Of-Flight(TOF) application, has been developed and tested. Time interval measurement is performed by the coarse counter and fine interpolator, which are utilized to measure the total periods and the residue time of the reference clock, respectively. Following a detail analysis of time precision and clock jitter in the two-step structure, the prototype TDC fabricated in GSMC 1P6M 0.18 μm CMOS Image Sensor(CIS) technology exhibits a Single-Shot Precision(SSP) of 11.415 ps and a dynamic range of 216.7 ns. In addition, a pixel of the chip occupies 100 μm×100 μm, and the measured Integral Nonlinearity(INL) and Differential Nonlinearity(DNL) are better than ±0.88 LSB and ±0.67 LSB, respectively. Meanwhile, the overall power consumption of the chip is 35 mW at 1.8 V power supply. Combined with these characteristics, the designed chip is suitable for TOF-based ranging applications.     

High Power 170 GHz Frequency Doubler Based on Ga As Schottky Diodes

The research on high power 170 GHz frequency doubler based on the Ga As Schottky diodes is proposed in this paper. This basic doubler cell is developed with a 50-μm-thick, 600-μm-wide, and 2-mm-long Al N substrate with high thermal conductivity to reduce the thermal effect. Besides, power combined frequency doubler has been fabricated to improve the power capacity by a factor of two. Great agreement has been achieved between the simulated results based on electrothermal model and measured perfor...     

Phase Noise Effects on the Performance of High-Order Digital Modulation Terahertz Communication System

As the carrier frequency goes into the terahertz band, the phase noise of the signal source has increasing impacts on the performance of the communication system. Considering a 16 QAM high-order digital modulation terahertz communication system(DMTCS),by comparing the influence of two kinds of local oscillator signal sources with different phase noise characteristics on the bit error rate(BER) performance of the system based on theoretical analysis and experimental research, it is found that the...     

Permeability analysis of fractured vuggy porous media based on homogenization theory

Based on the characteristics of fractured vuggy porous media,a novel mathematical model was proposed to model fluid flow in such media on fine scale,i.e.,the discrete fracture-vug network model.The new model consists of three systems:porous rock system,fracture system,and vug system.The fractures and vugs are embedded in porous rock,and the isolated vugs could be connected via the discrete fracture network.The flow in porous rock and fractures follows Darcy's law,and the vugs system is free fluid region.Usi...