基于m-n变进制规则的动态图软件水印算法?

针对软件水印分存算法恢复缓慢、数据扩张的缺点,提出一种基于m-n变进制规则的动态图软件水印算法,利用水印信息、m-n变进制数、排列数与置换图之间的对应关系,实现水印的分存和编码。当水印嵌入时,根据变进制规则将水印信息分存为一组变进制数,构造一个完美哈希函数将变进制数映射为对应的排列数,把得到的排列数编码为置换图结构嵌入到程序的执行代码中,水印提取是水印嵌入的逆过程。实验结果表明,该算法能减小程序的负载,降低水印嵌入和提取的时间复杂度,增强水印的隐蔽性和纠错能力。     

变路网情况下车辆路径问题建模及应用

受车辆调度中的一类现实需求启发,提出了路网结构可变情况下的车辆路径问题。探讨了路网变动对车辆路径的影响,在描述可变路网的基础上,基于路网、路径双层优化思想,建立了问题优化模型。考虑到路网变化给问题求解带来的复杂性,给出了改进遗传算法与随机递归算法相结合的求解策略。作为模型的直接应用和说明,最后的算例验证了模型和算法的合理性、有效性。     

基于响应面的变复杂度气动分析模型

结合变复杂度和响应面近似建模方法，采用CFD和工程估算气动分析方法，构建了基于响应面校准的变复杂度气动分析模型。以冲压发动机导弹为例，采用拉丁超方取样技术，选取6个CFD计算状态，建立了差值和比值校准响应面，并比较校准后的气动性能与CFD分析。结果显示，基于差值校准响应面的变复杂度方法具有较好的逼近能力和计算效率，适合于飞行器多学科设计优化过程的气动分析。     

多级异地远程控制系统中的权限管理

在多级控制系统中，控制权限的正确设置与管理对整个多级远程系统能否安全可靠运行起着至关重要的作用。本文介绍了利用西门子的Win CC中的内部变量来实现多级控制系统的权限设置与管理，并在黄河引黄涵闸远程监控系统中获得了成功的应用。     

Robust position control of DC servomechanism with output measurement noise

This note presents a systematic robust control method for DC servomechanism based on the sliding mode technique. The noise in the measured position is considered. The proposed approach guaranteed system robustness against parameter variations and external disturbances. The common requirement of an integral function in the formulation of sliding surface is eliminated. The position tracking error dynamics in the sliding mode is assigned. Several practical techniques for implementing the control scheme are provided as well.     

可变时滞系统的控制与仿真

炉温变化时硬质合金真空烧结炉的时滞常数变化很大，常规PID控制不能同时在高温段与低温段满足生产工艺提出的控制品质要求。本文在利用最小二乘法拟合出真空烧结炉时滞常数与炉温变化函数的基础上，PID参数采用经典的CHR整定算法随炉温变化实时整定，并利用MAT—LAB仿真软件对该控制算法在真空烧结炉中的应用进行了仿真研究，结果表明该算法能够实现对真空炉的有效控制，控制系统能够满意地跟踪设定的温度曲线。     

空调循环水泵变流量控制多泵同时变频调节的重要意义

空调循环水系统中,多台水泵运行时多台同步变频调节和单台变频调节的比较     

Time derivative equations for mode I fatigue crack growth in metals

Predicting fatigue crack growth in metals remains a difficult task since the available models based on the Paris law are cycle-derivative equations (da/dN), while service loads are often far from being cyclic. This imposes a cycle-reconstruction of the load sequence, which significantly modifies the load history in the signal. The main objective of this paper is therefore to propose a set of time-derivative equations for fatigue crack growth in order to avoid any cycle reconstruction. The model is based on the thermodynamics of dissipative processes. Its main originality lies in the introduction of a supplementary state variable for the crack, which allows describing continuously the state of the crack throughout any complex load sequence. The state of the crack is considered to be fully characterized at the global scale by its length a, its plastic blunting ρ, and its elastic opening. In the equations, special attention is paid to the elastic energy stored inside the crack tip plastic zone, since, in practice, residual stresses at the crack tip are known to considerably influence fatigue crack growth. The model consists finally in two laws: a crack propagation law, which is a relationship between dρ/dt and da/dt and which observes the inequality stemming from the inequality of Clausius Duhem, and an elastic–plastic constitutive behaviour for the cracked structure, which provides dρ/dt versus load and which stems from the energy balance equation. The model was implemented and tested. It successfully reproduces the main features of fatigue crack growth as reported in the literature, such as the Paris law, the stress ratio effect, and the overload retardation effect.     

适用于H.264视频解码器的VLD设计

设计了一种适合于H-264的变字长解码器，根据码流特点进行模块划分，减少硬件开销；采用并行结构解NAL包，解码效率高；采用了桶形移位器，进行并行解码，每个时钟解一个码字。采用Verilog语言进行设计、仿真，并通过了FPGA验证，可以在FPGA上实时解码标准清晰度的H．264视频。用0．18μm CMOS工艺库作综合，电路规模为1．6万门左右，最高频率能够达到150MHz。     

离散不确定系统预估+ 步长修正变结构控制

在现有文献的基础上，给出一种预估＋步长修正的离散变结构控制律设计方法，该方法可用于离散时间不确定系统变结构控制，有效地抑制切换函数的发散振荡，克服现有方法中条件限制过程的缺点，仿真结果表明，该方法具有收敛性好，抖振小，鲁棒性强的优点。