Stable local dimensionality reduction approaches

Dimensionality reduction is a big challenge in many areas. A large number of local approaches, stemming from statistics or geometry, have been developed. However, in practice these local approaches are often in lack of robustness, since in contrast to maximum variance unfolding (MVU), which explicitly unfolds the manifold, they merely characterize local geometry structure. Moreover, the eigenproblems that they encounter, are hard to solve. We propose a unified framework that explicitly unfolds the manifold and reformulate local approaches as the semi-definite programs instead of the above-mentioned eigenproblems. Three well-known algorithms, locally linear embedding (LLE), laplacian eigenmaps (LE) and local tangent space alignment (LTSA) are reinterpreted and improved within this framework. Several experiments are presented to demonstrate the potential of our framework and the improvements of these local algorithms.     

Mean square detectability of LTI systems over finite-state digital block-fading channels

This paper studies the mean square quadratic (MSQ) detectability for multi-output networked systems over finite-state digital block-fading channels. The packet-loss rate of each digital fading channel depends on the channel power gain, as well as packet length and power level used for transmission. A finite-state random process is introduced to model time-varying fading channels, which characterizes various configurations of physical communication environment and/or different channel fading amplitudes. Necessary and sufficient conditions for MSQ detectability over finite-state Markov digital block-fading channels are given in the form of algebraic Riccati equations or linear matrix inequalities (LMIs). The estimation gain is given as a function of estimated/observed channel state. In addition, explicit conditions on network for MSQ detectability over finite-state independent identically distributed (i.i.d.) digital block-fading channels are presented in terms of the unstable poles of the multi-output plant. Finally, an application to Gilbert-Elliott channels (GECs) is provided to demonstrate the derived results.     

一种基于鲁棒局部纹理特征的背景差分方法

针对复杂场景下运动目标的精确检测这一问题,提出一种对噪声鲁棒并具备灰度尺度不变性的局部纹理特征描述子LBP_Center,将其与像素的颜色信息结合应用于背景建模中,采用随机抽样的机制更新模型,同时引入背景复杂度以去除多模态动态背景产生的噪点。在标准测试数据集上的实验结果表明,该算法对柔性阴影及光照缓慢变化具备良好的鲁棒性,综合性能更优。     

一种基于FS401的高分辨率视频转换器设计

介绍了VGA高分辨率视频分配设计原理和TV视频转换的系统原理与总体架构.基于FS401视频处理器和VGA视频分配技术的应用,设计开发了一种高分辨率VGA-TV视频转换器.在分析视频格式转换基本原理及FS401芯片功能结构基础上,对视频转换器的硬、软件进行设计,最终开发出视频转换器电路板并应用于实际系统中.实测结果表明,...     

一种新的指纹图像合成分割法

在研究和分析传统方差法和最大类间方差法的基础上,提出了一种传统方差法和最大类间方差法相结合的分块处理分割算法。该算法首先求出整个指纹图像的方差,然后计算每一子块的方差。若方差小于整个图像的方差则用方差法对图像进行分割,否则用最大类间方差法进行分割。最后再对图像进行平滑处理。实验结果表明,相对于传统分割方法,该方法无需根据经验选取阈值,能较准确地分割出前景和背景,抗噪能力强,对高对比度和低对比度的图像均具有很好的分割效果。     

整理车间多Agent生产管理系统的建模与过程优化

借助多Agent技术,提出了一种基于多Agent的生产管理结构模型,对用户实际需求和结构模型的合理性进行了分析.在此基础上,开发了一个柔性、动态、高效的生产管理系统,对车间目前的生产管理模式进行了优化.同时,对多个体Agent的主要功能、工作原理和系统建模过程进行了介绍.实际应用表明,多Agent的生产管理系统,解决了...     

C语言中“/”影响运算精度问题的探讨

使用C语言编程进行计算的时候常常会因为不注意类型转换产生问题,尤其是在使用除法运算符"/"的时候,经常因为没有注意运算数据类型转换,从而导致运算结果不正确或着说是精度不够的问题。以下就C语言中"/"影响运算精度的问题做简单的探讨,希望助于初学者甚至是有一定编程水平的人更好地使用C语言。     

A Service-Centric Multicast Architecture and Routing Protocol

In this paper, we present a new multicast architecture and the corresponding multicast routing protocol for providing efficient and flexible multicast services over the Internet. Traditional multicast protocols construct and update the multicast tree in a distributed manner, which may cause two problems: first, since each node has only local or partial information on the network topology and group membership, it is difficult to build an efficient multicast tree and, second, due to the lack of complete information, broadcast is often used for sending control packets and data packets, which consumes a great deal of network bandwidth. In the newly proposed multicast architecture, a few powerful routers, called m-routers, collect multicast-related information and process multicast requests based on the information collected. The m-routers handle most of the multicast-related tasks, whereas other routers in the network only need to perform minimum functions for routing. The m-routers are designed to be able to handle simultaneous many-to-many communications efficiently. The new multicast routing protocol, called the Service-Centric Multicast Protocol (SCMP), builds a shared multicast tree rooted at the m-router for each group. The multicast tree is computed in the m-router by employing the Delay-Constrained Dynamic Multicast (DCDM) algorithm, which dynamically builds a delay-constrained multicast tree and minimizes the tree cost as well. The physical construction of the multicast tree over the Internet is performed by a special type of self-routing packets in order to minimize the protocol overhead. Our simulation results on ns-2 demonstrate that the new SCMP protocol outperforms other existing protocols and is a promising alternative for providing efficient and flexible multicast services over the Internet.     

浅析高校周边环境规划设计和教育环境的特色化建设的关系

随着社会化的发展,对各项环境指标的要求,教育环境的优化也成为了当前比较重要的值得重视的一个方面,这也是一个教育和教育环境相结合的整合形态,是一个值得深入研究的问题。本文从作者对本校大门以及校园周边环境的设计分析得出高校教育环境是需要一个特色化的建设过程的,这个特色化不仅包括人文环境的特色化,更重要的是人文环境要和校园实际规划环境相完美结合,才能创造出更加利于师生学习的优化环境。