基于FPGA的双通道旋转变压器测角系统设计

设计了用于星载设备的双通道多对极旋转变压器的角度测量系统.以获取高精度的电机旋转角度值为目的,在旋转变压器测角工作原理、误差分析以及双通道数据组合算法和测角系统软硬件设计等方面进行了研究,并选用FPGA对步进电机的角位移量进行探测与解算.为验证所设计的双通道旋变角度测量系统的精度,采用了分辨率更高的海德汉光电编码器进行...     

A 1 V 186-μW 50-MS/s 10-bit subrange SAR ADC in 130-nm CMOS process

This paper presents a 10-bit 50-MS/s subrange successive-approximation register (SAR) analog-to-digital converter (ADC) composed of a 4-bit SAR coarse ADC and a 6-bit SAR fine ADC. In the coarse ADC, multi-comparator SAR architecture is used to reduce the digital logic propagation delay, and a traditional asynchronous SAR ADC with monotonic switching method is used as the fine ADC. With that combination, power dissipation also can be much reduced. Meanwhile, a modified SAR control logic is adopted in the fine ADC to speed up the conversion and other techniques, such as splitting capacitors array, are borrowed to reduce the power consumption. Fabricated with 1P8M 130-nm CMOS technology, the proposed SAR ADC achieves 51.6-dB signal to noise and distortion ratio (SNDR) and consumes 186 μ W at 50 MS/s with a 1-V supply, resulting in a figure of merit (FOM) of 12 fJ/conversion-step. The core area is only 0.045 mm².     

太赫兹网络中基于优先级调度的低开销双信道MAC协议

针对现有太赫兹通信网络双信道MAC协议存在控制开销冗余和在竞争信道时缺少优先级调度策略等问题,提出了一种太赫兹网络中基于优先级调度的低开销双信道MAC协议（Low Overhead Dual-channel MAC Protocol Based on Priority Scheduling,LO-PSMAC）,包含通信距离预判、优先级调度策略的CSMA/CA和精简THz频段MAC帧三种机制,可有效提升信道利用率和整体网络吞吐量,同时减小控制开销和降低数据平均时延。仿真结果表明,所提协议与现有太赫兹双信道MAC协议相比,MAC层吞吐量和信道利用率分别提升了7.14%和14.75%,数据平均时延降低了14.21%。     

基于热光效应的智能窗薄膜材料

基于半导体和金属间的相变特性,重点介绍了基于热光效应的二氧化钒薄膜材料,描述了当前国内外的研究进展.给出了能应用于智能窗的纳米二氧化钒薄膜材料,并与常规的二氧化钒薄膜材料进行了分析比较.对这种智能窗薄膜材料的原理与应用前景进行了评述.可以预计,随着对太阳能材料的不断研究与开发,基于热光效应的智能窗薄膜材料在太阳能利用方面将具有巨大潜力.     

锁相环频率综合器中高性能电荷泵设计

本文基于0.18μm CMOS工艺设计并实现了一种新的高性能电荷泵电路。采用宽输入范围的轨到轨运算放大器和自偏置共源共栅电流镜技术提高了电荷泵在宽输出电压范围内的电流匹配精度;同时,提出通过增加预充电电流源技术来提高电荷泵的初始充电电流,以缩短CPPLLs的建立时间。测试结果表明电荷泵在0.4～1.7V输出电压范围内失配电流小于0.4%,充电电流为100μA,预充电电流为70μA。在1.8V电源电压下,电荷泵电路锁定时的平均功耗为0.9mW。     

Novel hollow Ni0.33Co0.67Se nanoprisms for high capacity lithium storage

In this work, homogeneous Ni_0.33Co_0.67Se hollow nanoprisms were synthesized successfully in virtue of Kirkendall effect. It is the first time for bimetallic Ni-Co compounds Ni_0.33Co_0.67Se to be used in lithium-ion batteries (LIBs). Impressively, the Ni_0.33Co_0.67Se hollow nanoprisms show superior specific capacity (1,575 mAh/g at the current density of 100 mA/g) and outstanding rate performance (850 mAh/g at 2,000 mA/g) as anode material for LIBs. This work proves the potential of bimetallic chalcogenide compounds as high performance anode materials for LIBs.

     

基于离散小波变换和感知哈希的加密医学图像检索算法

针对加密存储在云服务器的医学图像安全检索问题,提出基于离散小波变换（DWT）和感知哈希的加密医学图像检索算法。首先结合Henon映射的特点对图像进行频域加密运算;然后,对加密医学图像进行小波分解,得到逼近原图的子图;其次,根据离散余弦变换（DCT）的特性,通过比较DCT各系数与系数均值的关系得到图像的感知哈希序列;最后通过比较感知哈希序列之间的归一化相关系数来实现对加密医学图像检索。与基于非负矩阵分解（NMF）的哈希算法相比,所提算法在高斯噪声下检索精度提高了近40%,且在JPEG压缩攻击、中值滤波攻击、缩放攻击和扭曲攻击下检索精度与之相差无几。实验结果表明,所提算法对于常规攻击和几何攻击具有较好的鲁棒性,同时降低了图像加密的时间复杂度。     

Hidden quality cost function of a product based on the cubic approximation of the Taylor expansion

The-Nominal-The-Best (N-type) loss function is established based on the Taylor expansion. Results become more accurate as more Taylor expansion items are retained. N-type loss function neglects terms with powers higher than two, which inevitably leads to a certain deviation between the calculated result and the true value. In this paper, Taylor expansion is retained to the third-order, and the quality loss function is extended to three items. The quality loss coefficients of each item are determined, and the asymmetric piecewise cubic quality loss function is established. The deviation between the cubic and quadratic functions is evaluated. The formula for calculating the hidden quality cost of a product is derived by choosing an appropriate density distribution function and using process capability. Two cases are utilised to analyse and discuss the quality loss and hidden quality cost of a product using the cubic quality loss and quadratic quality loss functions. This paper provides a more accurate approach for the study of product quality management.     

NLOS环境下基于TOA/AOA的单基站目标跟踪

现有的单基站定位技术由于非视距（Non-Line-of-Sight,NLOS）误差的存在,导致定位性能急剧下降。针对这一问题,提出了一种基于单基站的改进扩展卡尔曼滤波（Extended Kalman Filter,EKF）算法。该算法在扩展卡尔曼滤波器中引入阈值去判断是否丢弃测量值,通过对卡尔曼增益的处理来提高对NLOS误差的滤除能力,最后利用扩展卡尔曼滤波器的跟踪性能对移动目标进行定位跟踪。仿真结果表明,所提算法的定位精度优于传统的EKF、无迹卡尔曼滤波器（Unscented Kalman Filter,UKF）等算法,且对抑制NLOS误差具有良好的效果。