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.     

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.     

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.     

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。     

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。     

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)     

A compile-time granularity analysis algorithm and its performance evaluation

A major implementation problem with implicitly parallel languages, is that small grain size can lead to execution overheads and reduced performance. We present a new granularity-analysis scheme that produces estimators, at compile time, of the relative execution weight of each procedure invocation. These estimators can be cheaply evaluated at runtime to approximate the relative task granularities, enabling intelligent scheduling decisions. Our method seeks to balance tradeoffs between analysis complexity, estimator accuracy, and runtime overhead of evaluating the estimator. To this end, rather than analyze data size or dependencies, we introduceiteration parameters to handle recursive procedures. This simplification facilitates solving the recurrence equations that describe the granularity estimators, and reduces the runtime overhead of evaluating these estimators. The algorithm is described in the context of concurrent logic programming languages, although the concepts are applicable to functional languages in general. We show, for a benchmark suite, that the method accurately estimates cost. Multiprocessor simulation results quantify the advantage of dynamically scheduling tasks with the granularity information.     

提高移动站点综合节能性能的新算法及性能分析

为减少移动站点(MS)的平均能耗(AEC)和其接收数据帧的平均等待时间(AWT),在分析IEEE802.16e规定的节能算法的基础上提出了一种休眠窗口的混合增长算法.该算法通过改变休眠窗口的增长速度,提高了移动站点节能综合性能.通过与IEEE802.16e规定的节能算法的对比分析和实验仿真验证了该算法的良好性能,并进一步考查了休眠模式中参数对算法性能的影响,有助于参数值的选取.结果表明:混合增长算法可以在获得更好节能特性的同时大大减少平均等待时间,尤其在到达率较低时,混合增长算法的平均能耗比指数增长算法降低15%～20%,平均等待时间减少50%～70%.     

MPI非阻塞广播算法及性能研究

MPI的3.0版新增了非阻塞集合通信.非阻塞集合通信兼顾非阻塞和集合通信的特点,与阻塞集合通信相比具有更低的同步开销,能够实现更多的计算通信重叠,带来性能提升.以广播为例详细介绍了广播通信的不同算法实现,比较了非阻塞与阻塞广播底层控制管理方法并进行了实验分析,提出了实现改进方法.     

Computational representation and analysis of emotion dynamics

Multimedia Tools and Applications - Human emotions are dynamic in nature. The intensity with which they are felt changes over time, and they have a natural timescale of expression, from onset to...     

整椭圆的三次NURBS表示及其应用

利用普劳茨算法对整椭圆的一种二次NURBS表示方案进行升阶,得到其三次NURBS表示。讨论了整椭圆的无限多种三次NURBS表示问题,并给出了适合工程应用的现成可用的结果,同时指出,同一椭圆不同的三次NURBS表示与有理线性参数变换相对应,即不同NURBS表示之间的差异主要在于曲线上点的参数值发生了变化。给出了具体的应用实例。     

软件质量的模糊属性及其表示

软件质量是一个模糊的概念,其主要表现是：软件质量等级通常以某一质量特性的指标值来划分,然而用户对软件质量的评价却是模糊的,为了处理软件质量的模糊属性,提出了3种描述软件质量（子）特性的模糊表示方法,并给出了这些表示方法的示例。     

Entropy based spatial domain image watermarking and its performance analysis

Digital image watermarking technique based on LSB Substitution and Hill Cipher is presented and examined in this paper. For better imperceptibility watermark is inserted in the spatial domain. Further the watermark is implanted in the Cover Image block having the highest entropy value. To improve the security of the watermark hill cipher encryption is used. Both subjective and objective image quality assessment technique has been used to evaluate the imperceptibility of the proposed scheme.Further, the perceptual perfection of the watermarked pictures accomplished in the proposed framework has been contrasted and some state-of-art watermarking strategies. Test results demonstrates that the displayed method is robust against different image processing attacks like Salt and Peppers, Gaussian filter attack, Median filter attacks, etc.

     

一种高速crossbar调度算法及其性能分析

分析了高速crossbar调度算法iSLIP在处理突发业务时性能严重恶化的原因。结合LQF/iLQF算法的思想,提出了又一种输入排队crossbar调度算法iPGQM。仿真结果表明:该调度算法在均匀业务流量下和iSLIP算法的性能基本相同;在突发业务的条件下,iPGQM算法具有更好的抗突发特性;特别在重负载的条件下,与iSLIP算法相比,不仅具有更高的吞吐量,而且平均延迟降低了10%左右。