A Subspace Approach to Timing Acquisition for Wavelet-Based Multirate Transmissions

We propose a subspace-based maximum-likelihood approach for acquiring the timing of wavelet-based multirate transmission systems. The S-curve analysis shows that our approach can correctly acquire the initial timing of a symbol from anywhere within a symbol-time interval at a cost of increasing jitter variance.     

A Unified Approach to Congestion Control and Node-Based Multipath Routing

The paper considers a TCP/IP-style network with flow control at end-systems based on congestion feedback and routing decisions at network nodes on a per-destination basis. The main generalization with respect to standard IP is to allow routers to split their traffic in a controlled way between the outgoing links. We formulate global optimization criteria, combining those used in the congestion control and traffic engineering, and propose decentralized controllers at sources and routers to reach these optimal points, based on congestion price feedback. We first consider adapting the traffic splits at routers to follow the negative price gradient; we prove this is globally stabilizing when combined with primal congestion control, but can exhibit oscillations in the case of dual congestion control. We then propose an alternative anticipatory control of routing, proving its stability for the case of dual congestion control. We present a concrete implementation of such algorithms, based on queueing delay as congestion price. We use TCP-FAST for congestion control and develop a multipath variant of the distance vector routing protocol RIP. We demonstrate through ns2-simulations the collective behavior of the system, in particular that it reaches the desired equilibrium points.     

A Factor Analytic Approach to Inferring Congestion Sharing Based on Flow Level Measurements

Internet traffic primarily consists of packets from elastic flows, i.e., Web transfers, file transfers, and e-mail, whose transmissions are mediated via the Transmission Control Protocol (TCP). In this paper, we develop a methodology to process TCP flow measurements in order to analyze throughput correlations among TCP flow classes that can be used to infer congestion sharing in the Internet. The primary contributions of this paper are: 1) development of a technique for processing flow records suitable for inferring congested resource sharing; 2) evaluation of the use of factor analysis on processed flow records to explore which TCP flow classes might share congested resources; and 3)validation of our inference methodology using bootstrap methods and nonintrusive, flow level measurements collected at a single network site. Our proposal for using flow level measurements to infer congestion sharing differs significantly from previous research that has employed packet level measurements for making inferences. Possible applications of our method include network monitoring and root cause analysis of poor performance     

A Wavelet-Based Approach for Steady-State Analysis of Nonlinear Circuits With Widely Separated Time Scales

We propose a new wavelet method for steady-state analysis of nonlinear circuits. The new method inherits the robustness of wavelet-based technique in handling very strong nonlinear circuits while offering significant reduction of simulation costs for circuits with widely separated time scales     

基于拥塞博弈的微服务运行时资源管理方法

随着云计算技术的不断发展,微服务体系结构逐渐成为一种广泛应用的软件设计风格.在基于微服务的应用系统中,微服务数量众多、相互依赖关系复杂、持续在线演化等特征使得微服务运行时资源的有效管理面临新的挑战.本文充分考虑微服务之间的关系特征,提出了一种基于拥塞博弈理论的运行时资源管理方法.首先,对微服务之间的复杂依赖关系进行建模,给出了带权有向无环图描述的微服务调用关系模型;然后,基于微服务关系调用模型对各个微服务的请求到达频率进行计算,并用排队论中的M/G/1队列刻画微服务处理请求的过程,进而设计了一种以服务等级协议（Service Level Agreement）满足程度为衡量标准的服务收益函数;最后利用拥塞博弈模型刻画对计算资源的竞争关系,给出了求解博弈的纳什均衡状态的多项式算法.实验表明,该方法在计算资源有限的场景下可以有效地提高微服务应用的整体性能.     

复杂背景下圆孔半径及圆心的图像检测方法

针对刷子插毛生产线的现实问题,本文给出了一种在复杂背景下圆孔的半径和圆心的图像检测方法。首先,根据扫描过程中角度不绝对垂直以及背景木板条纹大小和方向的不确定性,采用图像增强方法提高了对比度;然后,用边缘点检测方法来确定目标范围,用数学形态学的方法提取目标;最后,用平均误差的算法提高精度。使用本方法,可以用图像检测代替用手工标尺的测量。实验结果表明:相对于传统检测方法,本文的方法定位效果好,提取目标效果佳,具有进一步提高目标检测精度的潜力。     

An Approach to High-Order Cumulants Used to Detect Multifrequency Signalsin Telephone Networks

1 Introduction There are two kinds of signals in distance telephone networks. One is a line signal, the other, a multifrequency signal. The multifrequency signals are divided into forward ones and backward ones. The forward signals adopt the coding patter…     

An Approach to High-Order Cumulants Used to Detect Multifrequency Signals in Telephone Networks

In accordance with the detecting process of multi-frequency signals between the offices in telephone networks, and in contrast with the autocorrelation method used to handle the multi-frequency signals, a fast,inexpensive and unbiased of cumulants estimation method is adopted in detecting signals. This detecting method is better for resisting noise performance and more practical than the autocorrelation method.     

基于文档分割的图像兴趣域检测及编码方法

结合数字图书馆系统建设和应用的需求,文章提出一种基于文档分割的自适应文档图像兴趣域编码方法.文章针对数字化文档结构特征,详细描述了一种基于块缩图和涂染技术的快速图文分割算法,该算法分割图文时不受文本倾斜和插图区域不规则的限制;在将插图域和文本域进行准确分割的基础上,文章提出了一种自适应生成插图兴趣域屏蔽图和兴趣域位移法的压缩编码算法,最后给出采用该方法压缩含插图的扫描文档的示例.     

A Generic Quantitative Approach to the Scheduling of Synchronous Packets in a Shared Uplink Wireless Channel

The scheduling logic at the base station of a shared wireless medium supports time-dependent (synchronous) applications by allocating timely transmission grants. To this end, it must take into account not only the deadlines of the pending packets, but also the channel conditions for each potential sender, the requirements of nonsynchronous applications, and the packet retransmission strategy. With respect to these factors, we identify three scheduling scenarios and show that the scheduler logic faces a different challenge in addressing each of them. We then present a generic scheduling algorithm that translates all the factors relevant to each scenario into a common profit parameter, and selects the most profitable transmission instances.     

角点与边缘信息相结合的遥感图像飞机检测新方法

利用遥感图像中飞机目标的边缘特征和角点特征,提出边缘与角点信息相结合的遥感图像飞机检测新方法.首先,进行Canny边缘检测,提取遥感图像中飞机目标边缘信息,并利用OTSU算法二值化处理图像;然后,进行Harris角点检测,找出满足飞机角点分布特征的区域,去除伪目标;最后,进行区域生长式聚类,通过求取类心最终确定飞机位置.对60幅高分辨率遥感图像进行飞机检测测试,正确检测出238架飞机中的220架,漏检18架,48个虚警.实验表明,该方法可以有效解决复杂背景下飞机检测问题,具有良好的检测性能.     

Analysis of Integrated Circuit System s by An Innovative Wavelet-Based Scattering Matrix Approach

This paper proposes the use of scattering parameters (S-parameters) in the wavelet domain for the analysis of coupled multiconductor transmission lines, high-speed integrated circuits, and interconnects. S-parameters-based computing techniques are widely used in the analysis of networks characterized by a large number of integrated devices and interconnects. The theoretical and practical definition of the wavelet-based S matrix is shown, and then some numerical examples of its use and potential in the analysis of systems with linear and nonlinear terminations is shown and compared with other numerical techniques. The computational costs and the memory requirements of the wavelet representation of scattering matrix are also addressed     

一种检测悬停直升机的新方法

首先对直升机旋翼的雷达回波进行建模和分析,在此基础上提出一种悬停直升机积累检测新方法即低通滤波和多级假设检验相结合的方法。理论分析和仿真实验表明,该方法简单实用,可以解决低信噪比情况下机载相控阵雷达对悬停典型直升机的检测问题。     

APuML: An Efficient Approach to Detect Mobile Phishing Webpages using Machine Learning

Wireless Personal Communications - The recent trend in wireless technology has been tremadously increased the demand of higher frequency bands from every corners of the mobile technology. As next...     

一种p2p Botnet在线检测方法研究

文章详细分析了p2p僵尸网络的生命周期以及网络特征,利用改进的SPRINT决策树和相似度度量函数,提出了一种新的在线综合检测方法,并论述了虚拟机环境搭建、原型系统设计和实验结果分析.实验结果表明,检测方法是可行的,具有较高的效率和可靠性.     

基于NDIS的恶意程序通信隐藏检测方法

通过研究当今恶意程序的发展趋势,系统比较在通信隐藏和检测方面的诸多技术和方法,综合分析它们存在的不足,提出了一种基于NDIS来进行恶意程序隐藏检测的方法,很好的补充了恶意程序检测体系,实验表明该方法可以检测出当前所有进行通信隐藏的恶意程序。     

基于小波的多传感器空间目标数据融合算法

在多传感器系统中,本文提出一种基于小波变换的数据融合算法,用于对空间目标的轨道参数进行精确预测。仿真实验表明,该算法适用于空间目标轨道参数等快时变数据,估计得到的轨道参数均方差,优于各个传感器的理论均方差,同时也小于LMS算法获得的均方差。     

一种基于小波变换的高倍数SAR原始数据压缩算法

该文提出了一种基于分块提升小波变换的SAR原始数据压缩算法。在该算法中,针对SAR原始数据特点,提出一种有效的小波子带比特分配策略,为获得最优量化增益,在高比特率和低比特率两种情况下,分别采用均匀和非均匀Lloyd-Max量化器对小波系数进行量化。实验结果表明,该算法与传统BAQ和BAVQ算法相比,在信噪比和图像质量等各方面指标都取得了明显的改善。