Numerical solution of nonlinear system of Klein–Gordon equations by cubic B-spline collocation method

A technique to approximate the solutions of nonlinear Klein–Gordon equation and Klein–Gordon-Schrödinger equations is presented separately. The approach is based on collocation of cubic B-spline functions. The above-mentioned equations are decomposed into a system of partial differential equations, which are further converted to an amenable system of ODEs. The obtained system has been solved by SSP-RK54 scheme. Numerical solutions are presented for five examples, to show the accuracy and usefulness of proposed approach. The approximate solutions of both the equations are computed without using any transformation and linearization. The technique can be applied with ease to solve linear and nonlinear PDEs and also reduces the computational work.     

Real-time nonlinear MPC and MHE for a large-scale mechatronic application

Progress in optimization algorithms and in computational hardware made deployment of Nonlinear Model Predictive Control (NMPC) and Moving Horizon Estimation (MHE) possible to mechatronic applications. This paper aims to assess the computational performance of NMPC and MHE for rotational start-up of Airborne Wind Energy systems. The capabilities offered by an automatic code generation tool are experimentally verified on a real physical system, using a model comprising 27 states and 4 inputs at a sampling frequency of 25 Hz. The results show the feedback times less than 5 ms for the NMPC with more than 1500 variables.     

片上集成光电微能源工艺兼容性及器件特性研究

根据暂存式光电微能源系统组成器件的制备工艺特点,提出了基于SOI晶片的光电微能源片上集成方案。主要工艺包括绝缘沟槽刻蚀、离子注入、氧化等,具有较好的制备工艺兼容性。另外,根据片上集成方案,对器件特性进行了研究。结果表明,光伏电池的转换效率为9.7%,NMOS管阈值电压、漏极反向击穿电压VT分别为0.98 V和31.97 V,NPN三极管的电流放大倍数、集电极-发射极之间击穿电压约为83 V和12 V。各器件特性满足系统工作要求,集成方案具有较好的可行性。     

一种高效强K—栅栏覆盖构建算法

K－栅栏覆盖是无线传感器网络覆盖控制的研究热点之一。本文构建了强栅栏覆盖模型,提出了分区强K－栅栏覆盖构建算法PMNSB,用最少的节点形成强栅栏。首先把监控区域分成多个子区域,通过匈牙利算法选用移动距离之和最少的网格集合为基准1－栅栏覆盖,缺少移动节点的子区域,选择附近区域的剩余移动节点修补形成1－栅栏覆盖。水平相邻的两个子区域之间构建竖直栅栏,这些1－栅栏合起来构成强K－栅栏覆盖。仿真结果证明了该方法的有效性,本文的研究对提升无线传感器网络的性能具有重要的理论与实际意义。     

关于雾霾污染的现状及治理方案的探讨＊

雾霾是雾与霾的混合物,雾霾湿度相对较大时,雾所占的成分居多;而在相对湿度为80%～90%时,霾所占的比例较大。在雾霾天气下,人们在室外的能见度特别低,给行车出行带来很大的不便,同时,还会给人们的健康带来严重的威胁。主要对雾霾污染的现状进行了分析,并重点提出治理雾霾污染的有效方案。     

现代商业区建筑供配电设计要点及对策初论

在经济的推动下,商业区数量日益增多,空间布局更加紧凑,用电量也随之大幅增加,管理更为困难。因此,要重视商业区建筑的供电配电。介绍了商业区建筑的特点,然后结合实际案例对其供配电进行了设计。     

Fast local image inpainting based on the Allen–Cahn model

In this paper, we propose a fast local image inpainting algorithm based on the Allen–Cahn model. The proposed algorithm is applied only on the inpainting domain and has two features. The first feature is that the pixel values in the inpainting domain are obtained by curvature-driven diffusions and utilizing the image information from the outside of the inpainting region. The second feature is that the pixel values outside of the inpainting region are the same as those in the original input image since we do not compute the outside of the inpainting region. Thus the proposed method is computationally efficient. We split the governing equation into one linear equation and one nonlinear equation by using an operator splitting technique. The linear equation is discretized by using a fully implicit scheme and the nonlinear equation is solved analytically. We prove the unconditional stability of the proposed scheme. To demonstrate the robustness and accuracy of the proposed method, various numerical results on real and synthetic images are presented.     

向家坝二期大坝混凝土施工方案优化与进度控制

向家坝二期工程具有水文地质条件复杂、工程量巨大、大坝结构复杂、浇筑设备众多且布置集中、大体积混凝土温控难度大、工期紧等特点。为确保工程质量与进度,在二期大坝混凝土浇筑过程中,根据现场实际情况,采取了一系列设计、施工方案优化与调整措施,不仅加快了施工进度、确保了电站初期下闸蓄水目标的实现,而且提前实现了抬高蓄水位运行的目标。详细介绍了施工方案的优化与调整过程,可供同类工程参考。     

阀门关闭速度对TVD格式数值模拟水击影响分析

采用总变差减小（TVD）格式模拟了一维有压管道水击过程,对管道中阀门突然关闭和缓慢关闭引起的水击压强进行了数值计算。通过改变阀门关闭速度,分析TVD格式对水击数值模拟精度的影响。结果表明,与传统经典差分二阶MC格式相比,阀门关闭速度越快,TVD格式捕捉激波间断的能力越强,模拟水击波效果越好;当阀门关闭速度缓慢到一定程度,TVD格式与MC计算方法所得结果基本吻合,与解析解最大误差不超过2%。说明TVD格式是数值模拟水击现象行之有效的方法之一。     

预应力锚索腐蚀耐久性试验方案设计探讨

预应力锚索在岩土工程加固中应用广泛,其腐蚀耐久性对工程运行安全至关重要,而相关的腐蚀变化规律及机理还有待进一步明确。在总结当前预应力锚索腐蚀耐久性研究成果的基础上,对其腐蚀耐久性室内加速试验方案设计进行了探讨。分析了影响腐蚀的主要因素并拟定了各因素的不同影响水平;采用正交设计方法优化试验方案并通过有限元方法对试验模型尺寸和应力分布进行了计算模拟优化和验证;介绍了模型制作等工艺步骤。相关成果可供类似耐久性试验方案设计参考。 