A new coupled high-order compact method for the three-dimensional nonlinear biharmonic equations

This paper presents a new family of fourth- compact finite difference schemes for the numerical solution of three-dimensional nonlinear biharmonic equations using coupled approach. The numerical solutions of unknown variable and its first- derivatives as well as v(=Δ u) are obtained not only in the interior but also at the boundary. A prominent contribution of this work is that the boundary conditions for the variable v are approximated more accurately, which plays an important role for the efficiency of calculation. Finally, numerical experiments are conducted to verify the feasibility of this new method and the high accuracy of these schemes, including the steady Navier–Stokes equation in terms of vorticity-stream function formulation.     

A high-order compact method for nonlinear Black–Scholes option pricing equations of American options

Due to transaction costs, illiquid markets, large investors or risks from an unprotected portfolio the assumptions in the classical Black–Scholes model become unrealistic and the model results in nonlinear, possibly degenerate, parabolic diffusion–convection equations. Since in general, a closed-form solution to the nonlinear Black–Scholes equation for American options does not exist (even in the linear case), these problems have to be solved numerically. We present from the literature different compact finite difference schemes to solve nonlinear Black–Scholes equations for American options with a nonlinear volatility function. As compact schemes cannot be directly applied to American type options, we use a fixed domain transformation proposed by ?ev?ovi? and show how the accuracy of the method can be increased to order four in space and time.     

Noise analysis compact differential evolution

This article proposes a compact algorithm for optimisation in noisy environments. This algorithm has a compact structure and employs differential evolution search logic. Since it is a compact algorithm, it does not store a population of solutions but a probabilistic representation of the population. This kind of algorithmic structure can be implemented in those real-world problems characterized by memory limitations. The degree of randomization contained in the compact structure allows a robust behaviour in the presence of noise. In addition the proposed algorithm employs the noise analysis survivor selection scheme. This scheme performs an analysis of the noise and automatically performs a re-sampling of the solutions in order to ensure both reliable pairwise comparisons and a minimal cost in terms of fitness evaluations. The noise analysis component can be reliably used in noise environments affected by Gaussian noise which allow an a priori analysis of the noise features. This situation is typical of problems where the fitness is computed by means of measurement devices. An extensive comparative analysis including four different noise levels has been included. Numerical results show that the proposed algorithm displays a very good performance since it regularly succeeds at handling diverse fitness landscapes characterized by diverse noise amplitudes.     

基于边界扫描技术的抗混淆自适应测试算法

针对现有边界扫描测试快速测试算法存在征兆混淆现象的问题,在深入分析多种测试算法的基础上,提出一种抗混淆的自适应测试算法.首先,通过分析走步算法的特点,给出一种走步算法的改进方案.该方案在保证算法完备性指标不变的情况下,提高了算法的紧凑性指标.在此基础上,结合改良计数序列算法,生成抗混淆自适应测试算法.该算法解决了改良计数序列算法存在的征兆混淆问题,极大提高了算法的完备性指标,且紧凑性指标较好.     

基于C^#的密集架串口通信服务的设计与实现

为了实现管理系统对存放档案的密集架进行灵活操作,特定制PLC与PC间的通信协议,通过com串口实现与硬件的通信。然后将控制方法以服务方式部署,并开放Socket监听端口,接收高层系统指令以控制密集架的相关动作。     

一类简约的粒子群算法

针对标准粒子群的早熟和局部粒子群的最优位置信息利用率低的问题,提出一类简约的粒子群算法,该算法包含两种改进的策略:初始阶段有区别的更新粒子速度,减少更新频率,当粒子的速度有利于种群的进化时,那么下一代粒子的速度则保持不变;当粒子位置变化不大时,采用基于正态分布的随机采样搜索策略来改变寻优方式,有效地控制种群多样性,避免了早熟现象的发生.仿真实验表明该算法具有更强的寻优能力和更高的稳定性.     

Effects of Ti addition on low carbon hot strips produced by CSP process

Large quantity of fine Ti（C,N） particles, 15-30 nm in size, were observed in low carbon hot strips added to a small amount of Ti and produced by CSP process. The results showed that the precipitation of Ti（C,N） mostly took place during soaking and hot rolling, which is significantly different from that in the conventional production. These fine Ti carbonitride particles could be very effective on the austenite grain refinement by hindering grain growth of recrystallized austenite. Their precipitation behavior was discussed and compared with that of the steels produced in the conventional production.     

建设项目实施阶段工程造价控制的合同管理

文章从造价控制的角度分析论证了加强建设工程合同管理的重要性。提出了合同订立阶段对工程合同类型的选择，合同的工程造价支付管理、工程造价变更管理、工程造价风险管理的思路和方法，以工程合同的主动有效管理，达到控制工程造价、保证建设项目顺利实施的目的。     

关于500kV紧凑型线路架线施工中的技术问题

阐述了500 kV罗平至百色紧凑型线路工程施工和监理过程中,电气距离控制、滑车安装、导线缠绕打绞、弧垂施工、相间间隔棒安装、金具更换等技术问题及采取的有效控制措施和处理方法.     

射频CMOS平面螺旋电感2-π等效电路模型参数的提取

从有理分式拟合方法出发,提出了用于射频CMOS平面螺旋电感2-π等效电路模型参数提取的新方法.通过比较提参后等效电路给出的S参数和实验测量的S参数,证明该方法的精度很高.此外,提参的策略非常直接,因此容易在CAD里面编程实现.提参得到的等效电路模型对于射频电路设计者来说也是非常有用的.