HHT在水下目标信号特征提取中的应用

将希尔伯特-黄变换（HHT）用于水下目标特征分析,利用HHT对实录舰船辐射信号进行了特征提取,结果表明其适用于水声非平稳信号的分析,与传统时频分析方法相比具有很强的自适应特性和较好的时频聚集性。     

电子类毕业设计实现方法探讨

针对电子类毕业设计的特点,本文分析了毕业设计中出现的一些常见问题并提出具体的解决方法.以"电子日历时钟系统"题目为例,阐述了毕业设计中课题选择、电路设计、系统仿真、实物制作、论文撰写及毕业设计考核等方面的内容.笔者结合多年的教学经验和具体设计流程,文章就毕业设计指导方法、质量监控手段、设计调试工具应用等方面的内容展开了研究和讨论.     

双传声器系统中的风噪声抑制方法研究

风噪声是自然界中最常见的一种噪声,严重影响着传声器拾音质量,并且其非平稳性使普通消噪方法（如谱减法等）不适用于风噪声抑制。本文分析了双传声器拾取的语声信号和风噪声信号的频域相干性,利用来自双传声器语声信号之间的强相干性和风噪声之间的弱相干性,采用Zelinski滤波器思路,考虑自由声场和扩散声场中风噪声和背景噪声的综合影响,设计了一种利用信号的相干性进行风噪声检测,进而准确估计风噪声相干系数的风噪声抑制滤波器。实验证明,文中提出的基于双传声器相干性原理的风噪声抑制方法较传统方法不仅在消噪性能上有较大提升,而且还具有运算量小、实时性强的特点,能够广泛应用于自由声场和扩散声场中的各类拾音系统。      

一种基于多协议电流复用双频段压控振荡器的设计

.本文设计了一种基于IEEE 802.11 a/b/g和蓝牙多协议零中频收发机中双频段压控振荡器.该振荡器使用电流复用的方法,即将两个工作在不同频段的压控振荡器串联堆叠,达到了降低功耗的目的.通过Aglient ADS仿真,结果表明本文所设计的双频段压控振荡器功耗为12.22 mW,2.44和5.23 GHz载频处的相位噪声分别为-126.2和-120.1dBc/Hz@1 MHz,其性能完全符合IEEE 802.11a/b/g和蓝牙协议的要求.该振荡器将采用0.18 μm CMOS工艺实现,芯片面积为1.18 mm×0.67 mm.     

基于纠错码理论的群组认证

为解决群组认证中非法签名难以标定的问题,本文基于数字通信系统中的纠错码理论,提出了一个非适应性组合群组认证方案.该方案首先根据纠错码理论构造认证节点分组算法,然后按照分组进行节点签名的批量认证,再对分组认证结果进行迭代,从而标定非法签名,最后进行了例证演示.复杂度分析表明,针对n个签名（含有r个非法签名）进行非法者标定的问题,运用群组认证的标定次数远远小于逐一认证的n次,准确性演化结果表明当r远远小于n时,群组认证非法签名的标定成功概率接近于1.     

Silicon waveguide-based single cavity Fano resonance temperature sensor

A compact Fano resonant temperature sensor composed of a micro-ring resonator (MRR) coupled double-T-shaped waveguide is developed. The coupling gap and coefficient of the device are optimized by the finite difference time domain (FDTD) method. The maximum slope ratio (SR) of the MRR-coupled single-T-shaped waveguide is ?2.13 dB/nm. The SR of the double-T-shaped waveguide is ?49.69 dB/nm which is 23 times that of the single-T-shaped waveguide. The simulation results show that the temperature sensitivity of optical intensity decreases with increasing temperature in the range from 303.6 K to 343.8 K. The wavelength-temperature sensitivity of the double-T-shaped waveguide microring is 76.5 pm/K. After introducing the double-T-shaped waveguide structure, the device''s performance is greatly improved, and the double-T-shaped waveguide has a good application prospect as a temperature sensor.     

基于Proteus和组态王的温度测控系统联合仿真

数据测控系统通常由下位机和上位机组成.为实现下位机和上位机协同设计,提高设计效率,本文采用Proteus和组态王联合仿真的方法,并以温度测控系统为实例,阐述了实现下位机和上位机联合仿真的具体过程.实验结果验证了本方法的可行性.     

Exemplar-Based Clustering Analysis Optimized by Genetic Algorithm

Exemplar-based clustering algorithm is very efficient to handle large scale and high dimensional data, while it does not require the user to specify many pa- rameters. For current algorithms, however, are the inabil- ities to identify the optimal results or specify the number of clusters automatically. To remedy these, in this work, we propose and explore the idea of exemplar-based cluster- ing analysis optimized by genetic algorithms, abbreviated as ECGA framework, which use genetic algorithms for op- timizing and combining the results. First, an exemplar- based clustering framework based on canonical genetic al- gorithm is introduced. Then the framework is optimized with three new genetic operators： （1） Geometry operator which limits the typology distribution of exemplars based on pair-wise distances, （2） EM operator which apply EM （Expectation maximization） algorithm to generate children from previous population and （3） Vertex substitution op- erator which is initialized with genetic algorithm and se- lect exemplars by using the variable neighborhood search meta-heuristic framework. Theoretical analysis proves the ECGA can achieve better chance to find the optimal clus- tering results. Experimental results on several synthetic and real data sets show our ECGA provide comparable or better results at the cost of slightly longer CPU time.     

利用动态密勒补偿电路解决LDO的稳定性问题

针对LDO稳压器的稳定性问题,设计了一种新颖的动态密勒补偿电路。与传统方法相比,该电路具有恒定的带宽,大大提高了系统的瞬态响应性能;同时将开环增益提高了30 dB左右,使LDO稳压器具有较高的电压调整率和负载调整率。通过具体投片,验证了该方法的正确性和可行性。     

一种低静态功耗的CMOS集成稳压器的实现

提出了一种静态功耗很低的CMOS集成稳压器的实现方法，详细分析了他的工作原理，并给出了具体电路、仿真波形以及分析数据。