飞剪的定位控制

针对飞剪剪切完后返回时的定位控制,提出分段直线控制与抛物线控制两种方法,使飞剪以最小的机械冲击力且不产生超调地返回原位。实践证明,用这两种方法进行定位控制,飞剪返回距原位不大于±15°,剪切棒材端面光滑,误差不大于2cm,剪切棒材的成材率大大提高。     

Moving coordinate frames for representation and visualization in four dimensions

In this paper we generalize the method of sweeping, which may be used for both object representation and object visualization, to objects in E⁴. The generalized sweeping method involves a trajectory in E⁴, and a three-dimensional cross-section orthogonal to the trajectory. Three alternatives are considered for specifying the relationship between the trajectory and the cross-section, namely the Frenet frame, modified Frenet frames, and the standard viewing-reference coordinate (VRC) frame, where each of these is generalized to the case of four dimensions. We have implemented the method using the four-dimensional VRC frame, and the method is illustrated here by means of two examples involving visualization of objects embedded in E⁴.     

Recognition of two-dimensional representation of urban environment for autonomous flying agents

In this paper the problem of a vision system implementation for autonomous flying agents is considered in the context of industrial inspection tasks performed by unmanned aerial vehicles. A syntactic algorithm of a two-dimensional object vectorization and recognition is proposed. An algorithm of two-dimensional map recognition has been introduced as well. The algorithms have been tested by using both artificial data and real data – the satellite image. They have turned out to be effective.     

Numerical analysis of the influence of internal number representation on accuracy of coordinate transformation of industrial robots

The increasing performance of microprocessor technology allows for more generalized and sophisticated control algorithms for advanced robot control systems. The extended number of numerical operations of these approaches requires that an analysis of the influence of the numerical accuracy on the performance of the algorithms be made during the development process. In this context a universal approach for the inverse transformation module for robot application is validated numerically.     

A novel binary image representation algorithm by using NAM and coordinate encoding procedure and its application to area calculation

We propose a novel binary image representation algorithm using the non-symmetry and anti-packing model and the coordinate encoding procedure （NAMCEP）. By tak- ing some idiomatic standard binary images in the field of image processing as typical test objects, and by comparing our proposed NAMCEP representation with linear quadtree （LQT）, binary tree （Bintree）, non-symmetry and anti-packing model （NAM） with K-lines （NAMK）, and NAM representa- tions, we show that NAMCEP can not only reduce the aver- age node, but also simultaneously improve the average com- pression. We also present a novel NAMCEP-based algorithm for area calculation and show experimentally that our algo- rithm offers significant improvements.     

A novel binary image representation algorithm by using NAM and coordinate encoding procedure and its application to area calculation

We propose a novel binary image representation algorithm using the non-symmetry and anti-packing model and the coordinate encoding procedure (NAMCEP). By taking some idiomatic standard binary images in the field of image processing as typical test objects, and by comparing our proposed NAMCEP representation with linear quadtree (LQT), binary tree (Bintree), non-symmetry and anti-packing model (NAM) with K-lines (NAMK), and NAM representations, we show that NAMCEP can not only reduce the average node, but also simultaneously improve the average compression. We also present a novel NAMCEP-based algorithm for area calculation and show experimentally that our algorithm offers significant improvements.     

Context and its representation

Recent work in HCI has argued that an adequate account of computer use and the user's understandings should pay attention to the contexts in which interactions take place. The paper reaffirms this claim and distinguishes some variants of it, but simultaneously argues that the specification of what is to count as ‘context’ is more problematic than is often supposed. Some empirical data in the form of a transcribed videotape of one interaction is discussed to illustrate the argument. Finally some implications for HCI are briefly considered.     

Nielsen方程的三重组合梯度表示及其稳定性分析

研究Nielsen方程的三重组合梯度表示以及方程零解稳定性.首先给出4类三重组合梯度系统及其性质.其次,给出完整系统和非完整系统的Nielsen方程转化成三重组合梯度系统的条件;将完整和非完整两类Nielsen方程分别化为三重组合梯度系统并研究方程的零解稳定性.最后,举例验证结果的应用.     

基于局部坐标稀疏表示和最小二乘的基因表达数据分类

局部坐标稀疏表示可以使测试样本由其近邻样本线性近似表示,借鉴此思想,在稀疏表示模型中引入局部距离加权并添加非负约束,求解得到测试样本在训练集上的表示系数,根据表示系数的大小剔除训练集中的噪声点,在新的训练集上进行最小二乘子空间分类。在6个基因表达数据集上的实验结果表明,所提算法可以进一步改善分类质量。     

Context-aware temporal network representation of event logs: Model and methods for process performance analysis

Analysing performance of business processes is an important vehicle to improve their operation. Specifically, an accurate assessment of sojourn times and remaining times enables bottleneck analysis and resource planning. Recently, methods to create respective performance models from event logs have been proposed. These works have several limitations, though: They either consider control-flow and performance information separately, or rely on an ad-hoc selection of temporal relations between events. In this paper, we introduce the Temporal Network Representation (TNR) of a log. It is based on Allen’s interval algebra, comprises the pairwise temporal relations for activity executions, and potentially incorporates the context in which these relations have been observed. We demonstrate the usefulness of the TNR for detecting (unrecorded) delays and for probabilistic mining of variants when modelling the performance of a process. In order to compare different models from the performance perspective, we further develop a framework for measuring performance fitness. Under this framework, TNR-based process discovery is guaranteed to dominate existing techniques in measuring performance characteristics of a process. In addition, we show how contextual information in terms of the congestion levels of the process can be mined in order to further improve capabilities for performance analysis. To illustrate the practical value of the proposed models, we evaluate our approaches with three real-life datasets. Our experiments show that the TNR yields an improvement in performance fitness over state-of-the-art algorithms, while congestion learning is able to accurately reconstruct congestion levels from event data.     

正交M ult i-agen t 遗传算法及其性能分析

将Multi—agent系统、遗传算法与正交试验设计方法相结合，提出一种新的遗传算法——正交Multi—agent遗传算法，其主要思想是：利用正交设计的方法产生初始化种群；用正交交叉算子代替传统的算术交叉算子；利用agent间的竞争作用与每个agent所具有的知识和自学习能力进行启发式搜索，以提高进化的速度，仿真试验和性能分析表明，正交Multi—agent遗传算法不但具有很强的全局优化能力和较快的收敛速度，而且具有很强的鲁棒性。     

一种新的混沌伪随机序列及其性能分析

提出了一种新的基于混沌系统的伪随机序列,该序列能有效避免迭代过程中舍入误差积累的影响;且随着对系统数值仿真步长(时间间隔)的差异或方程参数值的微小变化,序列完全相异。分析表明该序列有很好的密码学特性,如接近于1的0-1比,类δ的自相关和接近于0的互相关特性,大线性复杂度。将其应用于图像加密中,结果表明是一类很有效的伪随机序列。     

一种高精度多通道采集系统及其性能分析

以电流、电压信号可选电路作为模拟信号的输入端口,从而实现模拟电压、电流信号均可被采集;再通过差分转单端的放大器,保证单端模拟信号进入模数转换器,将经转换后的数字量保存在FPGA的缓存区中。处理器FPGA控制数据采集系统的所有操作。通过模数器件与数模器件间联调,并对采集结果做适当的标定,得知此数据采集系统精度可达到14bit。     

稳定广义预测控制与性能分析

基于已有的一种稳定广义预测控制(SGPC)结构,以参考信号为优化变量对目标函数进行寻优,求出了控制器的滚动最优控制律,该控制律可以无静差地跟踪常数设定值.文中给出并证明了SGPC闭环控制系统的稳定性充分条件.数值仿真表明,该SGPC控制器可以保证闭环系统无稳态误差,并且适用于具有近似相消零极点的被控对象.     

Modelling of Chevron electrothermal actuator and its performance analysis

Microsystem Technologies - In this work, a Chevron electrothermal actuator is designed and its analytical model is developed. Chevron actuator works on the principle of Joules heating effect and...     

三层结构的网络游戏服务器设计及其性能分析

鉴于现有的网络游戏服务器端一个线程对应一个客户端的情况,提出了一个扩展的多路复用模式的服务器模型,基于该思想设计了一种游戏应用服务器。在此基础上对该模型的应用服务器进行了性能分析。游戏应用服务器运行测试表明这种服务器模型具有可用性和高效性。     

Fiber soliton-form 3R regenerator and its performance analysis

A novel fiber optical 3R regenerator based on optical soliton-effect using highly nonlinear fiber is constructed and investigated for the needs of the high rate and long-haul optical communications. The propagation equation of the pulses in the proposed optical 3R regenerator with the control of optical modulator and filter is established. By the use of the variational approach, the evolution of the distorted optical pulses in the regenerator and the functions of reamplification, reshaping, and retiming are investigated. The relation between the construction parameters and the output performance of the regenerator is discussed. The stable operation condition of the regenerator is revealed.     

A robust TDOA-based location method and its performance analysis

Based on time difference of arrive (TDOA), the regularized constrained total least square (RCTLS) algorithm for passive location is presented in this paper. RCLTS is used to solve the location equations by transforming the nonlinear equations about TDOA into linear equations about parameters of the position and range and expanding the true TDOA in a first-order Taylor series about measurement TDOA. A proper weight is chosen by the least mean square error (MSE) rule to obtain the location solution through analyzing the location error, whose feasibility and effectiveness are well proved by computer simulations. The CRB and GDOP for TDOA-based location are given. Supported by the Program for New Century Excellent Talents in University, Ministry of Education, China (Grant No. NCET-05-0803)     

混沌系统参数扰动方案及分析

对混沌系统施以扰动可以有效解决由于计算机有限精度效应导致的混沌系统动力学特性退化问题。基于区间映射中Cantor集的构造方法,提出一种数字混沌系统参数扰动方案,该方案将混沌系统每次迭代后得到的序列值等比例地扩散到压缩后的混沌状态参数取值区间上,从而达到扰动混沌序列的目的。实验仿真及分析表明,增加扰动后的混沌系统具有更好的混沌特性、更大的参数范围和更高的复杂度。