基于EZ_USB与FX2的通用数据传输模块设计

介绍了一种基于EZ_USBFX2单片机的通用数据传输模块,讨论了USB控制器EZ-USBFX2(CY7C68013)的性能及传输方式并给出了该系统的硬件实现方案。通过使用Cypress公司提供的GPIFDesigner工具开发GPIF(通用可编程接口),预先定义好波形描述符,通过激发GPIF功能来实现数据传输。     

通用可编程接口IP核的设计与实现

为满足SoC外设接口高带宽、外部电路接口多样性的要求,利用可编程状态机和波形描述符存储器,设计了一种通用可编程接口IP核.分别从接口硬件连接设计、固件程序设计、波形描述符设计和仿真平台设计等方面对接口的设计流程进行了详述.以8051 CPU核为基础,利用所设计的接口IP核构建了仿真验证环境,对接口IP核编程后实现了对外部存储器的访问,并通过比较写出和读入的数据验证了设计的正确性.     

非刚性三维形状匹配中基于谱分析的形状描述符综述

基于谱分析的形状描述符在非刚性三维形状匹配中取得了较好的匹配效果，引起了研究者的广泛关注.谱分析是基于流形上拉普拉斯贝尔特拉米算子谱分解的一种内蕴形状分析方法.谱形状描述符和谱距离分布函数是最主要的两类谱分析形状描述符，它们具有不同的数学性质和物理意义.基于两类不同的形状描述符，给出了详细的方法分析及其在形状匹配中的应用.首先，给出了应用基于谱分析的形状描述符的非刚性三维形状匹配框架，介绍了几种常用的谱形状描述符及谱距离分布函数的基本思想和计算方法；然后，分析比较了这些形状描述符的优缺点及应用场景，为研究者选择基于谱分析的形状描述符提供参考；最后，通过实验对比了不同基于谱分析的形状描述符的算法鲁棒性、时间耗费及非刚性匹配性能，以此推动谱分析形状描述符的应用进程.     

残差增强的图像描述符

针对增大视觉码书在提高图像全局描述符——局部特征聚合描述符(VLAD)精度的同时会增加VLAD存储开销的问题,提出一种基于2层结构层次视觉码书生成残差增强的图像全局描述符EVLAD.离线码书生成阶段,首先通过K-means算法生成第1层视觉码书,然后基于量化残差最小化原则非均匀地生成第2层各视觉子码书.在线EVLAD生成阶段,图像局部特征首先面向细粒度的第2层视觉子码书生成量化残差;然后面向第1层视觉码书进行聚集生成各子向量,EVLAD即为各子向量的串联结果,为了抑制特征空间爆发现象,各子向量和串联结果分别进行了L_2归一化.实验结果表明, EVLAD精度优于VLAD和其他各种改进方法.     

具有子串检索功能的可扩展分布式数据结构

EH*S是可扩展分布式数据结构EH*的一个改进，增加了子串检索功能。通过对子串和关键字计算描述符向量，为EH*文件中的每个桶添加一个桶描述符向量，然后把子串描述符向量分别与关键字和桶的描述符向量进行比较，得到包含子串的关键字集。     

基于深度学习的局部描述符

局部描述符提取是计算机视觉的一个基本问题,目前图像几何信息的获取还主要依靠传统的局部描述符。深度学习在图像分类,图像分割等领域已经获得了极大的成功。经我们了解传统局部描述符没有基于深度学习提取到的描述符精度高,导致之后计算有偏差甚至出现错误,现今研究正热的SLAM主要应用传统手工局部描述符。由于传统的描述符在精度方面还不能达到一个令人满意的效果,所以我们准备用一个深度学习描述符来代替传统手工局部描述符,形成一个较为完整的"基于深度学习的视觉SLAM"。最后,展望深度学习局部描述符的未来和前景。     

利用FIFOs实现USB与DSP的高速数据传输

利用两片SN74V245实现了TMS320C6201与EZ-USB FX2LP系列芯片CY7C68013A的连接,介绍了TMS320C6201的外部存储接口(EMIF)和CY7C68013A的通用可编程接口(GPIF)以及它们与SN74V245的连接方案,深入研究了GPIF的波形描述符编写和固件程序开发.     

USB与DSP数据通信接口设计

利用两片SN74V225实现了TMS320C6202B与EZ-USB FX2LP系列芯片CY7C68013A的连接,介绍了TMS320C6203B的扩展总线接口(XBUS)和CY7C68013A的通用可编程接口(GPIF)以及它们与SN74V225的连接方案,深入研究了GPIF的波形描述符编写和固件程序开发.     

吉时利发布SignalMeister2．0版波形生成软件

2008年7月8日，美国吉时利（Keithley）仪器公司发布了2．0版的SignalMeister波形生成软件，这是一款具有全新性能和可用性的强大射频开发工具。SignalMeister2．0具有全新的“面向对象”图形用户界面（GUI），是当前市面上唯一一款采用基于对象方式的波形生成软件，通过它，射频工程师可以使用图形对象直观地生成各种简单或复杂的波形。这种面向对象的GUI专门针对MIMO信号进行了优化，允许用户生成的测试波形范围被大大扩展。SignalMeister2．0能够生成符合WiMAX和WLAN无线连接标准以及3GPP和3GPP2蜂窝标准的所有信号。     

小波轮廓描述符及在图像查询中的应用

该文提出一种基于小波变换方法对目标形状的描述方法．在给出小波轮廓描述符数学定义的基础上,详细分析和实验验证了描述符的各个性质,并讨论了描述符的实际计算问题．另外结合基于内容的图像查询对小波轮廓描述符与傅里叶轮廓描述符的描述和检索性能进行了比较,证实了小波轮廓描述符的优越性．     

钻铣镗类加工中心的概念设计与方案评估研究

提出一种基于多色集合理论的机械产品概念设计的推理算法．采用一个有效的多目标方案评估算法，综合应用了层次分析法、模糊规则和神经网络，对满足需求的方案集进行评估和优化选择，得出满足需求的最优方案．以钻铣镗类加工中心的方案设计为例，用文中方法进行概念设计，得到了能满足需求的方案集和最优方案。     

基于LabVIEW8.6的材料输运性测量系统设计

针对连续变温条件下,材料的电输运特性难以准确测量和实时分析问题,设计一种基于LabVIEW8.6的材料电输运特性实时测量和分析系统。该系统首先选择高精度的电流电压表作为主要测量部件,以高精度的温控仪和压缩机作为改变材料环境温度的控制部件,再利用Labview 8.6编程灵活、界面直观的特点,设计能实时采集和处理数据的高精度材料电输运性能测量软件系统,直观显示出材料在不同环境下的电输运特性图,并实时保存测量数据。通过对两种材料的特性测试,表明了本系统具有快速的数据采集和处理能力,具有高精度的测量能力,避免人工测量方法无法实时处理和分析数据的缺点,为材料电输运特性测量提供了一种新的方案,同时为设计高性能的电子器件提供了参考。     

Optimal and suboptimal control of bundle of trajectories of deterministic logical-dynamical systems

The optimal control problem for deterministic logical-dynamical systems, with their continuous part described by differential equations and their discrete part described by recurrence equations, which simulate the operation of an automaton with memory, is considered. Algorithms for constructing the suboptimal guaranteeing and suboptimal on average controls under uncertainty are proposed based on sufficient optimality conditions for complete feedback control. It is shown that for linear logical-dynamical systems with the quadratic control criterion, the optimal open-loop control of the bundle coincides with the optimal control of its trajectory, i.e., the suboptimal control is optimal. Examples are given to illustrate the way to apply optimality and suboptimality conditions.     

Method of calculating the collision integral and solution of the Boltzmann kinetic equation for simple gases,gas mixtures and gases with rotational degrees of freedom

The conservative method of calculating the Boltzmann collision integral for simple gases, gas mixtures and gases with rotational degrees of freedom of molecules is presented. In all cases the common approach based on the projection technique of summing up the contributions in the collision integral is used. The method is applied for solving the Boltzmann kinetic equation for two fundamental rarefied gas flow problems: the heat transfer problem and the problem of shock wave structure. A comparison with experimental and numerical data of other authors is reported. It is shown that the considered numerical method allows one to solve the Boltzmann equation for real gases with high accuracy.     

Application of multi-level signals to the identification of direction-dependent processes

Theoretical results for the output and the input-output crosscorrelation function are derived for first order direction-dependent processes perturbed using pseudo-random maximum length ternary (MLT) signals with unsymmetrical signal levels. The analytical results are valid if the process output is either always increasing or always decreasing when the input is at its median level of zero. It is shown that, although this is not normally the case for the whole of the signal period, good approximations to the analytical results are obtained when it is the case for most of the signal period, as can be achieved with a suitable choice of signal levels. MLT signals with unequal spacing between signal levels can also be used to minimise the nonlinear distortion. This is equivalent to compensating for the direction-dependent behaviour of the system by preceding it with a static nonlinearity. Based on the theoretical and simulation results obtained, a novel technique is proposed to allow the best linear approximation of the process to be estimated from the ratio between the amount of time when the output increases to that when it decreases. The proposed method is shown to be applicable even when the number of signal levels is greater than three, and is less susceptible to the effects of noise than the method of correlation analysis and least squares.     

An Approach to Mathematical Modeling of Ill-Posed Problems of Dynamics of Distributed-Parameter Systems

A technique for mathematical modeling of a state of a distributed-parameter dynamic system with incomplete data about their initial boundary conditions is proposed in the paper. Modeling accuracy and uniqueness conditions are formulated. An algorithm is proposed for recalculation of modeling results for different numbers of discrete observations of the initial boundary state of the system with point modeling effects.     

Optimal and suboptimal control for sets of trajectories of deterministic continuous-discrete systems

The optimal control problem for deterministic continuous-discrete systems whose continuous part is described by differential equations and the discrete part, by recurrence equations simulating the control device operation, is considered. Based on sufficient optimality conditions for complete feedback control, algorithms for construction of optimal control with limited set of exact measurements and suboptimal guaranteeing and suboptimal on average controls under uncertainty conditions are proposed. It is shown that for linear continuous-discrete systems with quadratic cost function the optimal open-loop control for the set coincides with the optimal control for one set trajectory, i.e., the suboptimal control is optimal. The application of optimality and suboptimality conditions is demonstrated using examples.     

GMW-序列的三项生成多项式

研究了GMW-序列的三项生成多项式问题,给出了其三项生成多项式的结构和计数,证明了其三项生成多项式个数远远少于同周期的m-序列,这说明GMW-序列在抵抗快速相关攻击的能力方面要强于同周期的m-序列。     

Enthalpy of formation of binary solid and liquid Mg alloys – Comparison of Miedema-model calculations with data reported in literature

Enthalpies of formation and mixing of binary solid and liquid magnesium alloys have been calculated by application of the Miedema model and compared with data reported in literature. The Miedema model has originally been developed for alloys containing at least one transition metal. The model parameters have been developed over the years and became fixed around the end of the nineteen eighties. In the present paper, the validity of the model is investigated for all binary Mg-alloy systems, also including alloys without a transition metal. The much larger number of literature data, that is presently available, allows for a more precise estimation of one of the model parameters associated with Mg and to adapted calculations for binaries of Mg with transition metals. In addition, an extension of the model to binaries of Mg with non-transition metals is introduced. For these alloys an additional negative contribution to the heat of formation and mixing is added.     

Sensitivity analysis for the dynamic response of thermoviscoplastic shells of revolution

A computational procedure is presented for evaluating the sensitivity coefficients of the dynamic axisymmetric, fully-coupled, thermoviscoplastic response of shells of revolution. The analytical formulation is based on Reissner's large deformation shell theory with the effects of large-strain, transverse shear deformation, rotatory inertia and moments turning around the normal to the middle surface included. The material model is chosen to be viscoplasticity with strain hardening and thermal hardening, and an associated flow rule is used with a von Mises effective stress. A mixed formulation is used for the shell equations with the fundamental unknowns consisting of six stress resultants, three generalized displacements and three velocity components. The energy-balance equation is solved using a Galerkin procedure, with the temperature as the fundamental unknown.Spatial discretization is performed in one dimension (meridional direction) for the momentum and constitutive equations of the shell, and in two dimensions (meridional and thickness directions) for the energy-balance equation. The temporal integration is performed by using an explicit central difference scheme (leap-frog method) for the momentum equation; a predictor-corrector version of the trapezoidal rule is used for the energy-balance equation; and an explicit scheme consistent with the central difference method is used to integrate the constitutive equations. The sensitivity coefficients are evaluated by using a direct differentiation approach. Numerical results are presented for a spherical cap subjected to step loading. The sensitivity coefficients are generated by evaluating the derivatives of the response quantities with respect to the thickness, mass density, Young's modulus, two of the material parameters characterizing the viscoplastic response and the three parameters characterizing the thermal response. Time histories of the response and sensitivity coefficients are presented, along with spatial distributions of some of these quantities at selected times.