适用于集成电路的大时间常数积分器的研究

鉴于普通的大时间常数积分器不能集成实现,提出了2种采用新型有源器件CDBA和CFA、利用时间常数倍增技术实现的大时间常数积分器结构．对这2种积分器结构进行了理论分析与对比,结果证明,由CFA实现的时间常数倍增积分器结构更为简单、理想和实用．     

The analysis of the integral gated mode single photon detector

This paper critically analyses and simulates the circuit configuration of the integral gated mode single photon detector which is proposed for eliminating the transient spikes problem of conventional gated mode single photon detector. The relationship between the values of the circuit elements and the effect of transient spikes cancellation has been obtained. With particular emphasis, the bias voltage of the avalanche photodiode and the output signal voltage of the integrator have been calculated. The obtained analysis results indicate that the output signal voltage of the integrator only relates to the total quantity of electricity of the avalanche charges by choosing the correct values of the circuit elements and integral time interval. These results can be used to optimize the performance of single photon detectors and provide guides for the design of single photon detectors.     

基于径向基逼近的KdV方程的无网格辛算法

基于径向基逼近理论,本文为KdV方程构造了一个无网格辛算法.首先借助径向基空间离散Hamilton函数以及Poisson括号,把KdV方程转化成一个有限维的Hamilton系统.然后用辛积分子离散有限维系统,得到辛算法.文章进一步讨论了所构造辛算法的收敛性和误差界.数值例子验证了理论分析.     

基于高效抽取滤波器的数字下变频设计

对数字下变频各个模块的构成及原理进行了研究,提出了一种基于高效抽取滤波器的实现方案,用查表法产生数字混频所需的高采样率的数字本振信号,用梳状滤波器和半带滤波器级联实现数字下变频的抽取和滤波.方案中多处使用了查表法,它相对于传统方法有节省资源,速度快,易于实现的优点.设计中调用了ALTREA参数化模块库中的资源,充分利用了芯片的硬件资源,从而提高了运算速度.还给出了半带滤波器的一个设计实例.该方案已通过FPGA验证.     

压控锯齿波发生器电路的研究

对单电源供电的迟滞比较器的门限电压进行了估算,给出了迟滞比较器的传输特性曲线,分析了压控锯齿波发生器的工作原理,推导了锯齿波的幅度及振荡周期的计算公式,并进行了实验验证.     

随机时滞非完整系统的自适应控制器设计

本文处理具有随机时滞的非完整系统的控制器设计问题。目标是对这类随机时滞非完整系统通过应用非连续控制,设计一个依概率全局渐进稳定控制器。基于第一个子系统的输出测量的切换控制方案的应用得到系统渐进稳定。应用基于建设性操作的积分反推技术来设计控制器。系统的依概率渐进稳定得到实现。仿真算例进一步证明了设计过程的有效性。     

数字LDI梯形滤波器的计算机模拟

本文叙述数字 LDI 梯形滤波器的计算机模拟方法.以一个3阶数字 LDI 低通滤波器为例说明模拟过程,并验征这种滤波器设计方法的正确性和可行性.     

Markov Chain Monte Carlo from Lagrangian Dynamics

Hamiltonian Monte Carlo (HMC) improves the computational efficiency of the Metropolis–Hastings algorithm by reducing its random walk behavior. Riemannian HMC (RHMC) further improves the performance of HMC by exploiting the geometric properties of the parameter space. However, the geometric integrator used for RHMC involves implicit equations that require fixed-point iterations. In some cases, the computational overhead for solving implicit equations undermines RHMC’s benefits. In an attempt to circumvent this problem, we propose an explicit integrator that replaces the momentum variable in RHMC by velocity. We show that the resulting transformation is equivalent to transforming Riemannian Hamiltonian dynamics to Lagrangian dynamics. Experimental results suggest that our method improves RHMC’s overall computational efficiency in the cases considered. All computer programs and datasets are available online (http://www.ics.uci.edu/babaks/Site/Codes.html) to allow replication of the results reported in this article.     

Dynamics of Charged Particles Around a Magnetized Black Hole with Pseudo–Newtonian Potential

The linear stability of equilibria of charged particles moving near a compact object with a dipole magnetic field and a pseudo-Newtonian potential is analyzed detailedly.An optimal fourth-order force gradient symplectic method,as a global symplectic integrator that can simultaneously solve both the equations of motion and the variational equations,is used to calculate fast Lyapunov indicators.In this way,dynamical structures are described,and parameter domains for causing chaos are found.     

引入整合风险的服务集成商模式农村末端物流资源整合

在对服务集成商模式农村末端物流资源运作特征进行简要分析以及关键因素挖掘和量化的基础上,分析了对整合决策具有重要影响作用的整合风险,提出了整合过程面临的主要风险类型并引入模糊综合评价法对整合风险进行了量化,建立了服务集成商模式农村末端物流资源整合优化模型,构建了相应的求解算法,并通过算例验证了模型和算法的可行性和有效性。