直觉模糊集Choquet积分在目标威胁估计中的应用

针对威胁估计过程具有一定的不确定性,威胁因素往往又具有一定的相关性问题,将直觉模糊集和模糊积分引入信息融合领域中,提出了基于直觉模糊集Choquet积分的威胁估计方法.首先,利用直觉模糊集理论构建了基于不同威胁因素的直觉模糊估计器,利用隶属度函数和非隶属度函数表示每个威胁估计器的不确定性.其次,利用模糊测度对威胁因素和因素集的重要程度进行建模.再通过Choquet模糊积分完成不同威胁估计器结果的集成,完成对目标威胁程度的估计.最后,以20批空中目标的威胁评估实例,验证了方法的有效性.     

基于知识推理的导向器类零件精铸模具单元体智能切分

导向器类零件分体式精铸的关键技术之一是切分得到蜡模模具设计的内、外环及叶片单元体即如何实现分割面的生成。应用数学推理表达经验知识,得到参数化分割面,为快捷准确的设计与制造导向器类零件精铸模具奠定了基础。     

摆动式TIG焊焊缝跟踪技术

介绍以弧压为传感信号的摆动式TIG焊焊缝跟踪技术。硬件设计方面，采用两级滤波的方法，前级主要用来保护控制电路，后级主要用来滤除杂波。软件处理方面，针对搭接TIG焊的特点，采用摆动焊接方法，利用积分比较法，实现了焊缝的自动跟踪；提出加权处理的方法，对积分比较法进行修正，进一步保证了跟踪的实现，提高了跟踪精度。试验证明，该技术控制可靠，焊缝跟踪效果好。     

CAS wavelet method for solving the fractional integro-differential equation with a weakly singular kernel

In this paper, a computational method for numerical solution of a class of integro-differential equations with a weakly singular kernel of fractional order which is based on Cos and Sin (CAS) wavelets and block pulse functions is introduced. Approximation of the arbitrary order weakly singular integral is also obtained. The fractional integro-differential equations with weakly singular kernel are transformed into a system of algebraic equations by using the operational matrix of fractional integration of CAS wavelets. The error analysis of CAS wavelets is given. Finally, the results of some numerical examples support the validity and applicability of the approach.     

基于二重积分滑动面的Buck变换器滑模研究

利用状态空间平均方法建立了Buck变换器的数学模型,该模型考虑了电容和电感的串联等效电阻,仿真结果与电路模型的仿真结果基本一致,其准确性较高;基于该数学模型,分别设计了PID控制和PWM滑模控制,滑模控制基于二重积分滑动面,并利用了电流信息。仿真结果表明,在负载突变情况下,基于二重积分滑动面的PWM滑模电流控制具有更好的动态响应特性和稳态误差调节特性。     

栅元有效共振积分的CUDA算法设计与实现

核反应堆中需要实时精确地计算堆芯和增殖材料的有效共振积分或群截面来实现反应堆的安全控制。整个计算过程因为涉及大量的积分运算和庞大的核素截面数据,采用常规的计算方法,计算时耗相当大。基于统一计算设备架构(CUDA)平台,利用图形处理器(GPU)的计算能力,对整个计算过程进行并行化分解,多线程同时运算,大幅度提升计算速度,降低时耗。实验结果表明,在GPU上并行计算所得结果与原始数据没有明显差异,且加速效果显著。     

Two general integral inequalities and their applications to stability analysis for systems with time‐varying delay

Integral inequalities have been widely used in stability analysis for systems with time‐varying delay because they directly produce bounds for integral terms with respect to quadratic functions. This paper presents two general integral inequalities from which almost all of the existing integral inequalities can be obtained, such as Jensen inequality, the Wirtinger‐based inequality, the Bessel–Legendre inequality, the Wirtinger‐based double integral inequality, and the auxiliary function‐based integral inequalities. Based on orthogonal polynomials defined in different inner spaces, various concrete single/multiple integral inequalities are obtained. They can produce more accurate bounds with more orthogonal polynomials considered. To show the effectiveness of the new inequalities, their applications to stability analysis for systems with time‐varying delay are demonstrated with two numerical examples. Copyright © 2016 John Wiley & Sons, Ltd.     

Robust stability and stabilization of uncertain linear positive systems via integral linear constraints: L1‐gain and L∞‐gain characterization

Copositive linear Lyapunov functions are used along with dissipativity theory for stability analysis and control of uncertain linear positive systems. Unlike usual results on linear systems, linear supply rates are employed here for robustness and performance analysis using L₁‐gain and L_∞‐gain. Robust stability analysis is performed using integral linear constraints for which several classes of uncertainties are discussed. The approach is then extended to robust stabilization and performance optimization. The obtained results are expressed in terms of robust linear programming problems that are equivalently turned into finite dimensional ones using Handelman's theorem. Several examples are provided for illustration. Copyright © 2012 John Wiley & Sons, Ltd.     

前馈和积分分离在超临界机组协调控制的应用

介绍了静态前馈的线性关系和动态前馈控制技术。针对华电潍坊发电有限公司2×670MW超临界机组协调控制的特点,论述了超临界机组协调控制中的锅炉指令、燃料指令、给水指令和燃料发热量（BTU）校正的要点。分析了积分分离的应用效果。     

基于平面矢量场的可视化方法的研究

平面矢量场可视化是科学计算可视化的重要研究内容。矢量场以直观的图形图像显示场的运动,透过抽象数据有效洞察其内涵本质和变化规律,广泛应用于计算流体力学、航空动力学、大气物理和气象分析等领域。对平面矢量场进行可视化的方法有很多种,常见的有点图标法、流线法、线积分卷积法和拓扑分析法等。论文主要研究常见的可视化方法,分析它们的性能,并通过实际的例子,对具体的可视化结果图像进行比较。通过该研究,能够给人们在选择可视化方法时提供依据。