一种DSP+FPGA实时信号处理系统

简要叙述了常用的信号处理系统的类型与处理机结构,介绍了正逐步得到广泛应用的DSP+FPGA处理机结构,在此基础上提出了一种实时信号处理的线性流水阵列,并举例说明了该结构的具体实现,最后分析说明了此结构的优越性。     

Resembling a Viper: Implications of Mimicry for Conservation of the Endangered Smooth Snake

The phenomenon of Batesian mimicry, where a palatable animal gains protection against predation by resembling an unpalatable model, has been a core interest of evolutionary biologists for 150 years. An extensive range of studies has focused on revealing mechanistic aspects of mimicry (shared education and generalization of predators) and the evolutionary dynamics of mimicry systems (co‐operation vs. conflict) and revealed that protective mimicry is widespread and is important for individual fitness. However, according to our knowledge, there are no case studies where mimicry theories have been applied to conservation of mimetic species. Theoretically, mimicry affects, for example, frequency dependency of predator avoidance learning and human induced mortality. We examined the case of the protected, endangered, nonvenomous smooth snake (Coronella austriaca) that mimics the nonprotected venomous adder (Vipera berus), both of which occur in the Åland archipelago, Finland. To quantify the added predation risk on smooth snakes caused by the rarity of vipers, we calculated risk estimates from experimental data. Resemblance of vipers enhances survival of smooth snakes against bird predation because many predators avoid touching venomous vipers. Mimetic resemblance is however disadvantageous against human predators, who kill venomous vipers and accidentally kill endangered, protected smooth snakes. We found that the effective population size of the adders in Åland is very low relative to its smooth snake mimic (28.93 and 41.35, respectively).Because Batesian mimicry is advantageous for the mimic only if model species exist in sufficiently high numbers, it is likely that the conservation program for smooth snakes will fail if adders continue to be destroyed. Understanding the population consequences of mimetic species may be crucial to the success of endangered species conservation. We suggest that when a Batesian mimic requires protection, conservation planners should not ignore the model species (or co‐mimic in Mullerian mimicry rings) even if it is not itself endangered. Implications of mimicry for Conservation of the endangered smooth snake     

一种低功耗高性能数据采集数字处理平台的设计

目的构建一套基于中频信号基带数字信号处理的软件无线电平台。方法通过选择芯片设计硬件电路设计出合适的PCB板。结果主要依据软件无线电平台,提出了一种基于A/D+FPGA+D/A的硬件设计方案,该系统包括了前端的A/D数据采集和后端的D/A模拟数据恢复的详细收发电路原理设计。结论构建了一个从前端数据接收到后端模拟发送的高速基带数字信号处理平台。     

海洋环境水下电场时频特征分析

目的掌握海洋环境水下电场主要能量来源和衰减规律。方法结合理论研究环境电场幅值随时间的变化规律,重点分析水下环境电场不同频带的频谱分布,最后计算得到海洋环境水下电场不同频点的幅值在整个频带所占比重。结果海洋环境水下电场随海水电导率和海水运动强度的减弱,幅值降低,能量主要集中在0.01~1 Hz的低频以及工频处,在一定的空间范围内海洋环境水下电场的一致性较强。结论实验结果与理论分析结果具有一定的吻合度。     

有限空间作业人员生理状态监测设备研制

为监测有限空间作业人员异常生理状况,进而保障有限空间作业安全与作业人员生命健康,在分析手腕处6个测量位置信号质量的基础上,获得最佳信号采集位置,并结合事故成因,从光电容积脉搏波(PPG)信号中提取心率、脉搏周期、振幅等生理参数作为评价指标,研制一款针对有限空间特殊作业人群的手腕处脉动生理信息监测设备;并进行系统稳定性测...     

基于微电荷法的烟气颗粒物浓度检测技术及其应用

目前针对烟气颗粒物浓度的检测方法较多,但均存在不足。详细分析了基于微电荷法的烟气颗粒物浓度检测技术的基本原理和关键的技术难点,介绍了由于微处理器、数字电子技术和材料科学等的飞速发展带来的技术革新,技术的进步为其应用开拓了更为广泛的应用领域并逐步在工业场合得到推广。     

基于汶川8.0级强震记录的近场地震动特征分析

在汶川8.0级大地震中,国家数字强震动台网布设在龙门山断裂带及其周围地区的50多个台站获得了大于100 Gal的加速度记录。选取其中断层附近11个台站的加速度记录,分别进行了地震反应谱分析和基于正交化HHT法的能量分布特征分析,通过对竖向与水平向加速度峰值比、竖向与水平向加速度反应谱比值,以及能量分布和峰值系数的分析与比较,探讨了汶川地震的近场地震动特征。     

基于设备网(DeviceNet)总线技术的矿井瓦斯传感器的设计

介绍瓦斯传感器的国内外研究现状,给出以设备网(DeviceNet)总线构成的瓦斯传感器检测网络结构。简要分析了DeviceNet总线协议特点以及其关键技术,提出具有DeviceNet总线规范的矿井瓦斯传感器的设计及实现方案。硬件电路主要由信号调理电路、数字信号处理器,以及能实现DeviceNet网络通信的接口电路构成,用对象建模的方法构建了矿井瓦斯传感器的对象模型,并用模块化编程技术实现了矿井瓦斯传感器作为一个网络从设备的应用层的软件设计。该传感器作为从设备和带有PCI-CAN网卡的计算机组成主/从连接网络,能对多个矿井瓦斯传感器的数据实现远距离的控制。     

绿灯倒计时信号对驾驶行为的影响

为揭示绿灯倒计时信号对交叉口交通安全的影响,针对不同交通负荷与信号控制方式下的驾驶行为开展研究。选择大连市内的倒计时信号交叉口与非倒计时信号交叉口各2处,开展车辆行驶速度及不良驾驶行为调查。用数理统计方法,对比分析2类交叉口在平峰与高峰时段的车辆行驶速度特性,同时对比分析上述不同条件下闯黄灯及违规变道行为的发生数量。研究表明,绿灯倒计时信号在绿灯时间末期,会诱发一部分驾驶员加速行驶通过交叉口;绿灯倒计时信号在平峰时段对闯黄灯行为数量的影响较小,而对违规变道行为的数量有显著影响。     

A dual-sensor-based method to recognize pipeline leakage and interference signals

During the detection of pipeline leakages, false alarms of leak detection could be markedly reduced if the interference signals resulting from pressure regulating, pump regulating or valve movements could be accurately distinguished. A digital recognition method for interference signals and leakage signals based on a dual-sensor system is proposed in this paper. It is demonstrated that the direction of the signal can be recognized by a cross-correlation calculation between two signals from the dual-sensor, one of which undergoes forward linear interpolation and backward linear interpolation. Based on this theory, the interference signal and the leak signal can be discriminated exactly, and the distance between the two sensors in the dual-sensor system can be considerably reduced without needing to increase the sampling frequency. The monotonicity of the cross-correlation function is demonstrated, and a fast discrimination algorithm based on a binary extreme search method, which decreases the computational load and maintains global optimization, is also proposed. A pre-processing method of the actual signal is proposed to decrease the identity requirement for the two sensors in a dual-sensor system. In the experiment based on artificial signals, the proposed discrimination algorithm could achieve accurate recognition of the abnormal signal, and as such, the theory and application of pipeline leak detection based on dual-sensor systems are extended.