Disturbance rejection of battery/ultracapacitor hybrid energy sources

This paper contributes an active control strategy to reject disturbances in hybrid energy source systems applied in hybrid electric vehicles. The disturbances include persistent disturbances introduced by engine torque ripples compensation, and transient disturbances caused by transient load power demands. The disturbance rejection is achieved via singular perturbation theory. The original system is a Port-Controlled Hamiltonian (PCH) system, and the controller is designed based on interconnection and damping assignment. Experimental results verify the effectiveness of the disturbance rejection control.     

(3+1)维修正KdV-Zakharov-Kuznetsov方程的行波解

结合动力系统分支理论,对一个非线性(3+1)维修正KdV-Zakharov-Kuznetsov方程进行理论上的研究.首先,根据不同参数值和三次方程判别式分别定性分析了平衡点的类型和相应轨线情况.其次,利用Ja-cobi椭圆函数,从形式上给出了若干有界行波解和同宿轨的公式,这一结论扩展了已有文献的工作.最后,利用Hami...     

基于逻辑Petri网的服务流程结构演化研究

流程结构演化是实现服务流程重构的一种有效手段,可以充分利用已有流程资源快速定制满足新业务需求的服务流程.然而,当前服务演化研究多关注于流程局部组成服务以及接口参数的兼容替换,对于流程结构演化所提供的操作过于简单,难以应对复杂流程演化场景.针对上述问题,提出一种基于逻辑Petri网的服务流程结构演化形式化描述方法.利用逻辑Petri网将服务流程建模为服务网,在服务网的基础上,针对不同的演化需求构建相应的结构演化运算;引入结构范式概念评价服务流程的结构健壮性,并借助逻辑Petri网的结构性质来分析与验证所建立的演化运算对流程结构范式的级别保持问题.给出了基于流程结构演化的服务流程定制框架,并基于所提出结构演化运算设计开发了仿真验证平台,验证了方法的有效性.     

基于代数正规型构造的代数免疫最优布尔函数

现有代数免疫最优布尔函数的构造方法大多基于支撑集,通过代数正规型直接构造的方法研究较少.为此,利用代数正规型的多项式表示构造一类代数免疫性质优的布尔函数,研究其代数次数、代数免疫阶、函数重量、非线性度等性质,分析采用这种方法构造的代数免疫最优布尔函数的性质及计数等结果.由构造方法可以得到代数免疫最优的布尔函数,其中包含一些已有的特殊构造结果,表明该方法更具有一般性,包含更多具有最优代数免疫阶的函数.     

示例学习的广义扩张矩阵算法及其实现

本文对扩张矩阵理论加以扩充，提出关于公式的扩张矩阵的概念，并据此实现一个广义扩张矩阵算法叫做ＡＥ９，本文还将ＡＥ９和ＡＱ１５应用于几个实际领域的学习问题，如睡眠状态的分类，手写数字识别等，结果都表明ＡＥ９比ＡＱ１５分类精度更高。     

改进的Koblitz曲线上数字签名算法

标量乘法的效率决定着椭圆曲线密码体制的性能,而JSF算法是当前最流行的计算椭圆曲线双标量乘的算法;Koblitz曲线上的快速标量乘算法是标量乘法研究的重要课题。Lee[12]算法采用Frobenius映射扩展正整数k并将其扩展后的系数改写成二进制形式有效地提高标量乘算法效率。将JSF应用到扩展后的系数中,以较小存储空间为代价来提高算法效率,并将算法运用到改进的ECDSA算法中,减少乘法运算次数,加速签名及验证过程,节约数字签名时间。     

一种表单Ajax信息项提取方法

提出一种表单Ajax信息项提取方法。该方法在独立于浏览器运行的程序中嵌入JavaScript引擎,本地化构建DOM对象和Ajax应用对象,利用JavaScript引擎跟踪执行脚本代码,模拟执行用户在浏览器下的操作,从而自动获取表单Ajax信息项数据。实验结果表明,该方法可以完整获取Deep Web查询接口的表单信息,提高搜索准确率。     

Design and implementation of a block‐backstepping based tracking control for nonholonomic wheeled mobile robot

This paper presents formulation of a novel block‐backstepping based control algorithm to overcome the challenges posed by the tracking and the stabilization problem for a differential drive wheeled mobile robot (WMR). At first, a two‐dimensional output vector for the WMR has been defined in such a manner that it would decouple the two control inputs and, thereby, allow the designer to formulate the control laws for the two inputs one at a time. Actually, the decoupling has been carried out in a way to convert the system into block‐strict feedback form. Thereafter, block‐backstepping control algorithm has been utilized to derive the expressions of the control inputs for the WMR system. The proposed block‐backstepping technique has further been enriched by incorporating an integral action for enhancing the steady state performance of the overall system. Global asymptotic stability of the overall system has been analyzed using Lyapunov stability criteria. Finally, the proposed control algorithm has been implemented on a laboratory scale differential drive WMR to verify the effectiveness of the proposed control law in real‐time environment. Indeed, the proposed design approach is novel in the sense that it has judiciously exploited the nonholonomic constraint of the WMR to result in a reduced order block‐backstepping controller for the WMR, and thereby, it has eventually yielded a compact expression of the control law that is amenable to real‐time implementation. Copyright © 2015 John Wiley & Sons, Ltd.     

关系数据规范理论第五范式的缺陷

剖析了连续依赖的本质。并提出其产生的条件和处理的方法。指出连续依赖出现在联系关系中，且并不少见。但不能以一组５ＮＦ去替代原关系。否则会丢失信息。必须采用该文提出的方法去处理。