高压浓相煤粉气力输送差压信号多分辨分析

为了探究高压浓相气力输送过程中时频空间的内部特征,利用六尺度多分辨小波分析对试验差压信号进行时频分解.引进能量、Shannon熵和标准差STD作为特征量对气固两相流频域空间进行分析.分析表明:浓相气力输送过程中,差压信号中的能量主要分布在低频区,Shannon熵从高频到低频上呈先减小后增大分布趋势.在相同的试验压力条件下,随着表观速度的增大,低频所占据的能量份额减小,信号脉动向高频移动;高频d1和d2的Shannon熵和a6上的STD增大,低频d4~d6上的Shannon熵和d1~d6上的STD减小.为进一步研究流型辨识及流动稳定性提供了新方法.     

Nuclear Norm Subspace System Identification and Its Application on a Stochastic Model of Plague

The discrete-time model of plague is deduced by zero-order holder based on the continuoustime model. Due to the existence of stochastic disturbances, the stochastic model is given corresponding to the discrete-time model. The state estimation and noise reduction of the stochastic model are achieved by designing Kalman filter. Nuclear norm minimization is to structure the low-rank matrix approximation instead of the singular value decomposition in the process of subspace system identification. According to the plague data from the World Health Organization, the system matrices and noise intensity of the model are identified. Simulations are carried out to show the higher approximation capability of the proposed method.     

面向手机的云端VR三维场景立体显示与交互框架

针对手机无法渲染可交互的高质量三维场景这一弊端,提出一种面向手机的云端VR应用框架。此框架结合云渲染和VR技术在手机端实现可交互高质量三维场景的立体显示,并以手机浏览器作为客户端,利用视频块流传输图像数据、消抖算法(AJA)处理交互数据,实现Web端轻量级渲染,不仅降低了移动端数据可视化运算成本,还避免使用插件和下载安装包。实验表明本文框架的显示帧率能达到30帧每秒,带宽控制在80 kb/s以内,能稳定地在手机上实现传统App无法实现的逼真VR体验。     

基于Unity3D的水下机器人半实物仿真系统

基于Unity3D研制了一种由地面控制终端、机器人本体和三维仿真系统3部分组成的水下机器人半实物仿真系统,为水下机器人开发过程中的性能测试、控制算法分析和人员操作培训提供了仿真和测试平台。该系统采用同一地面控制终端作为三维仿真系统和机器人控制系统的统一指令输入源,以实现虚拟对象和机器人本体的同步工作,可对系统进行实时监测、调参。采用多目视觉技术对机器人位置采集,对传感器数据进行卡尔曼滤波处理。机器人运动仿真试验结果表明,机器人实际运动路径和仿真规划路径基本相同,该系统动态响应性和控制系统同步性较好。     

城市疫情传播和复工强度建模及相关性分析

以多源大数据为基础构建模型,分析全国34个典型城市因疫情导致的人口迁徙变化和人力缺口,并通过迁徙基数推算其他各城市的复工强度。仿真结果证明SEIR仓室模型能够较好地模拟此次疫情发展趋势,利用其估计各城市内部新型冠状病毒感染肺炎的基本再生数,结合人力缺口对复工强度进行回顾性的矩阵分析,以总结我国此次抗疫经验。相关性分析阶段对K-means无监督聚类后的城市集群进行回归分析,结果表明对于大部分城市而言,复工强度的大小与其人力缺口、基本再生数以及人均GDP水平有明显的相关关系。     

Credit Scoring Based on the Set-Valued Identification Method

Credit scoring is one of the key problems in financial risk managements. This paper studies the credit scoring problem based on the set-valued identification method, which is used to explain the relation between the individual attribute vectors and classification for the credit worthy and credit worthless lenders. In particular, system parameters are estimated by the set-valued identification algorithm based on a given recognition criteria. In order to illustrate the efficiency of the proposed method, practical experiments are conducted for credit card applicants of Australia and credit card holders from Taiwan, respectively. The empirical results show that the set-valued model has a higher prediction accuracy on both small and large numbers of data set compared with logistic regression model. Furthermore, parameters estimated by the set-valued identification method are more stable,which provide a meaningful and logical explanation for extracting factors that influence the borrowers' credit scorings.     

Dynamic Event-Triggered Control for Nonlinear Systems: A Small-Gain Approach

An event-triggered control(ETC) system transmits data packages and updates control inputs only when the predefined criterion is satisfied. In this way, network communication and computing resources are scheduled more reasonably in contrast to the traditional periodic sampling strategy.Small-gain approach proposed in recent literatures is a new modeling method to deal with nonlinear ETC systems. Different from traditional ETC models, stability criteria are proposed in the form of input to state stability(ISS) gain to design the triggering mechanisms. This paper introduces additional dynamic variables in this model and proposes a small-gain based dynamic event-triggered strategy.Sufficient conditions to guarantee the stability of the system are derived with the help of cyclic-smallgain theorem and Zeno behaviors are avoided to ensure the feasibility of this method in practical applications. Numerical simulations are given to demonstrate the effectiveness of our approach.     

自适应的无线融断网络路由算法研究

无线融断网络具有长延时、高动态拓扑、链路不稳定等特点,伴随着网络联接缺乏源端到目的端的持续性,为解决网络通信困难的问题,将多头绒泡菌的智能性和自适应性引入,提出一种自适应的无线融断网络路由算法。搭建无线融断网络模型,推导出链路容量的数学表达;设计下一跳节点的选择策略和最佳路由选择策略,实现在融断网络环境下的数据尽力投递。仿真实验表明,该算法能够在网络开销率较低的情况下,达到良好的数据投递,且平均延迟小。     

Fault tolerant motion planning based on joint torque limit for redundant manipulators

0 IntroductionWith the development of science and technology,manipulators have been widely utilized in some specialfields of space , deeper ocean, and nuclear materialcleanup.Becausethese workingenvironments are distant ,harsh and dangerous ,itis difficultfor peopletorepairthefailed manipulators onthe spot .Therefore ,the manipula-tors should operate normally for a long time . To meetthese requirements ,the manipulators must have not onlyhigher reliability but also fault tolerance capabilities…     

Fabrication of solenoid-type microinductor with different magnetic core schemes by MEMS technique

0 IntroductionThere has been a great demand on micro DC/DCconverter for the applications of the portable electronicproducts such as mobile communication product CDMA(Code Division Multiple Access) ,portable notebookcom-puter ,microprocessor ,digital camcorder andso on.Mag-netic components such as inductors and transformers arethe essential components in constructingthe power supplytransformer ,filter , oscillator , amplifier and micro DC/DCconverter ,andthe miniaturization of inductor an…