嵌入式DSP系统中SDF模型的层次化存储优化方法

在同步数据流模型(SDF)描述的嵌入式数字信号处理(DSP)系统中,计算体单一出现调度(SAS)算法对于存在反馈环和数据密集处理的应用不可解或内存优化效果很差.文中提出了将SAS和Non-SAS类型调度算法相结合的层次化的存储优化方法,定义了数据密集分量和强连通分量来描述环和数据密集处理结构,并依据数据优先消耗原则设计了启发式的Non-SAS调度算法对分量进行存储优化.该方法适用于任意SDF模型,并有良好的存储优化效果.实验结果证明了其有效性.     

使用SDF图描述的嵌入式DSP系统存储优化

提出一种嵌入式DSP系统的存储优化方法．该方法利用遗传算法求得存储需求量较少的同步数据流(Synchronous Data Flow,SDF)图顶点调度序列;使用TPFIFO(Two-Port FIFO)数据缓冲模型来实现顶点输入边和输出边的存储共享,以进一步提高数据缓冲的利用率．实验结果证实了该方法的有效性．     

同步数据流语言高阶运算消去的可信翻译

Lustre是一种广泛应用于工业界核心安全级控制系统的同步数据流语言,采用形式化验证的方法实现Lustre到C的编译器可以有效地提高编译器的可信度.基于这种方法,开展了从Lustre*(一种类Lustre语言)到C子集Clight的可信编译器的研究.由于Lustre*与Clight之间巨大的语言差异,整个编译过程划分为多个层次,每个层次完成特定的翻译工作.阐述了其中高阶运算消去的翻译算法,翻译过程采用辅助定理证明工具Coq实现,并进行严格的正确性证明.     

同步数据流模型调度序列的空间优化

提出了一种嵌入式DSP系统的存储优化方法。该方法基于同步数据流模型SDF（Synchronous Data Flow）。针对其他优化算法不适用于存在反馈环的同步数据流模型的问题,该方法为反馈环的空间优化设计实现了启发式的调度算法,并提出了将SAS（Single Appearance Schedules）和Non-SAS类型调度序列相结合的层次化的空间优化方案,为同步数据流模型调度序列的空间优化提供一个通用的解决方案。实验结果证实了该方案的有效性。     

汽车减震器参数同步数据采集系统设计

为了解决汽车减震器运行时压力与位移信号难以同步采集的问题,设计了一种基于51单片机和AD7572的同步数据采集系统.系统通过51单片机控制两个独立的高速A/D转换通道同步采集压力与位移信号,采用USB串口与上位机通信实现数据的储存、传输和处理.示功图对比表明,该系统可以完成减震器关键参数的同步采集,具有较高的实用价值.     

多传感轨道扣件检测的数据同步采集系统设计

针对轨道扣件检测的多传感数据同步采集,首先,在分析线阵CCD相机成像原理的基础上,根据系统的要求对相机的关键参数进行了选择并设计了采集方案。然后,设计了传感器的信号调理电路,包括电平调整电路以及抗混叠滤波器的设计,提高了传感器的抗干扰能力。并通过STM32获取光电编码器的等间隔脉冲信息,对各个传感器进行触发控制,设计了线阵相机与惯性传感器的同步触发方案。最后,编写了上位机软件实现了数据的同步采集。实验结果表明,该系统能够精确采集各传感器的数据,具有较强的抗干扰能力和稳定性。     

Minimization of demand paging for the LRU stack model of program behavior

The minimization of page faults in a demand paging environment where program behavior is described by the LRU stack model is studied. Previous work on this subject considered a specific type of stack probability distribution. As there exist practical situations which do not satisfy this assumption, we extend the analysis to arbitrary distributions. The minimization is stated as an optimization problem under constraints, a method to obtain a class of optimal solution is presented, and a fixed-space replacement algorithm to implement these solutions is proposed. The parameters of this replacement algorithm can be varied to adapt to specific stack probability distributions and to the number of allocated pages in memory. This paper also determines a necessary and sufficient condition for the optimality of the LRU algorithm.     

同步数据流语言可信编译器Vélus与L2C的比较

同步数据流语言（如Lustre、Signal）在航空、高铁、核电等安全关键领域得到广泛应用.例如,适合这些领域实时控制系统建模和开发的Scade工具就是基于一种类Lustre语言.这类语言相关开发工具,特别是编译器的安全性问题也自然受到高度关注.近年来,基于形式化验证实现可信编译器构造成为程序设计语言领域的研究焦点之一,也取得了瞩目的成果,如CompCert项目实现了产品级的可信C编译器.同样,人们也采用这种方法开展了同步数据流语言可信编译器的研发工作.主要关注从事这一工作的两个长线项目,二者均研发面向基于Lustre的同步数据流语言编译器,分别以Vélus和L2C代称.对Vélus和L2C从多个重要的角度进行较为深入的分析与比较.     

6-DOF磁悬浮轴承同步数据采集系统设计

以6自由度磁悬浮定位平台控制系统为研究对象,结合被控对象的实际特点,在平面磁悬浮平台(PAMB)数学模型的基础上,介绍了一种用于磁悬浮轴承实时控制的数据采集与处理系统。采用DSP作为主控单元,对传感器信号高速采集。由于A/D集成在DSP内部,可以对两路信号精确同步采样。对数据进行运算后,实现D/A转换输出控制电压信号。控制软件采用JTAG接口下载到DSP的内部闪存。为了方便实时改写参数,还设计了DSP与计算机通讯接口。仿真结果表明,这种控制方案有较好的动态和静态特性。     

永磁同步电机功率驱动电路的分析与设计

以小功率三相永磁同步电动机为控制对象,推导出交流伺服系统中功率驱动电路的设计原理与方法,详细介绍了主电路的拓扑结构和重要元器件的参数设计过程,同时为了便于实现永磁同步电机的闭环控制,为系统的主要信号设计了相应的检测电路,并在此基础上设计了完善的保护电路;此外,为了解决功率驱动电路中电源种类繁多的问题,提出了一种基于开关电源技术的系统电源解决方案;实际应用表明,据此开发的功率驱动电路性能稳定,功能完善,具有很高的可靠性.     

Test Data Sets and Evaluation of Gene Prediction Programs on the Rice Genome

With several rice genome projects approaching completion gene prediction/finding by computer algorithms has become an urgent task. Two test sets were constructed by mapping the newly published 28,469 full-length KOME rice cDNA to the RGP BAC clone sequences of Oryza sativa ssp. japonica: a single-gene set of 550 sequences and a multi-gene set of 62 sequences with 271 genes. These data sets were used to evaluate five ab initio gene prediction programs: RiceHMM, GlimmerR, GeneMark, FGENSH and BGF. The predictions were compared on nucleotide, exon and whole gene structure levels using commonly accepted measures and several new measures. The test results show a progress in performance in chronological order. At the same time complementarity of the programs hints on the possibility of further improvement and on the feasibility of reaching better performance by combining several gene-finders.     

一种智能大气数据测量系统的设计与实现

大气数据测量系统是飞行器的重要组成部分,为飞行控制系统提供高度和速度等重要的信息源,设计了一种采用硅压阻传感器和DSP技术实现的大气数据测量系统,建立了系统的数学模型,提出了系统的组成方案,给出了系统的工作原理图和部分硬件电路图等,对系统的误差源进行了分析和消除,最后对系统进行了具体实现;该系统已投入使用,实践表明,其测量精度高（气压高度精度可达5m）、可靠性高、智能化程度较高。     

A review of stochastic algorithms with continuous value function approximation and some new approximate policy iteration algorithms for multidimensional continuous applications

We review the literature on approximate dynamic programming, with the goal of better understanding the theory behind practical algorithms for solving dynamic programs with continuous and vector-valued states and actions and complex information processes. We build on the literature that has addressed the well-known problem of multidimensional (and possibly continuous) states, and the extensive literature on model-free dynamic programming, which also assumes that the expectation in Bellman’s equation cannot be computed. However, we point out complications that arise when the actions/controls are vector-valued and possibly continuous. We then describe some recent research by the authors on approximate policy iteration algorithms that offer convergence guarantees (with technical assumptions) for both parametric and nonparametric architectures for the value function.     

高精度微波引导设备角度数据检测系统设计与实现

针对当前某高精度微波引导设备的角度制导性能精准检测难度大的问题,基于ARM+DSP+FPGA的总体架构,研究并搭建了高精度角度数据检测系统的硬件电路结构,基于C/C++、VHDL和Verilog开发了角度数据测试软硬件程序,实现了对微波引导设备空间角度、数据信号的接收、处理、解算和测量;并进行试验验证,结果表明该系统实现了设计功能、达到了指标要求,对高精度微波引导设备角度测量方位角优于0.16°,仰角优于0.18°,数据字与设备预置信息一致,满足高精度角度、数据的检测要求,对有效提高该微波引导设备的可靠性具有重要意义。     

水培水质监控系统实时数据管理

实时数据管理是水培水质监控系统的核心部分，设计实现了数据管理中心DMC对系统实时数据的管理，DMC通过内存实时数据库管理生产监控系统的实时数据信息。介绍了数据管理中心服务接口的设计和实现，系统其他模块通过调用数据管理中心的接口完成相应的功能操作。     

学生体检数据统计及资料管理系统软件设计

学生健康体检是中小学必做的一项重要工作。长期以来,基层保健医生一直从事着繁重的手工报表统计工作,不但工作繁多,而且出错的几率很高,效率低。本文依据现行的学生体检标准以及多年工作实践,采用Delphi平台开发,目的在于把基层保健医生从繁重的手工劳动中解放出来,及时提供高效、准备的体检数据。因此,本文对于提高此项工作的工作效率,改进工作方法,具有参考意义。     

On Joint Control of Heating,Ventilation, and Air Conditioning and Natural Ventilation in a Meeting Room for Energy Saving

In this paper, we consider the optimal joint control of heating, ventilation, and air conditioning systems and natural ventilation during the start‐up period of these systems in a meeting room. The joint control policy could reduce the total energy consumption in the building, but the optimal policy could be complex and difficult to implement in practice. In order to address this dilemma, we make the following major contributions. First, we theoretically show that the optimal control policy of heating, ventilation and air conditioning can be well approximated by the threshold policies after natural ventilation is applied; the optimal control policy of natural ventilation can be greatly approximated by the threshold policy, when the indoor air temperature as a function of time has monotonicity after the heating, ventilation and air conditioning policy is applied. Furthermore, we establish a rule‐based law framework for the policy approximation of joint control of heating, ventilation, and air conditioning and natural ventilation. Second, we propose the thresholds estimation framework for the policy approximation of fan coil unit, fresh air unit, and natural ventilation respectively, based on the dynamic of the outdoor air temperature, the indoor base air temperature, and the indoor air temperature after the heating, ventilation, and air conditioning policy is applied. Finally, we compare the performance loss, the indoor comfort violation rate, and computational complexity under the approximated policy with those under the dynamic programming, the optimized artificial neural network method, [24–26], and the small sampling and machine learning method [27]. Numerical testing results show that our method saves the computing time dramatically with no effect on the comfort of occupants and little performance degradation.     

继电器分断过压信号采集装置的设计与实现

继电器的寿命直接影响到使用电器设备的可靠性。在其性能指标中,继电器触点在分断时产生的频率高、幅值大的过电压信号是重要的指标之一。为了采集到该信号,该文根据数据采集系统性能要求,采用以DSP为核心,以及DSP的外扩器件制作成高速数据采集卡,插入PC机的ISA总线插槽中;PC机与DSP构成主从结构,通过DMA(直接存储器存取)方式把采集的数据传送到PC机进行处理。利用本系统对继电器分断时产生的过电压信号进行采集,可以得到幅值大约750V,频率10kHz的信号。