Model-based approach to spatial–temporal sampling of video clips for video object detection by classification

For a variety of applications such as video surveillance and event annotation, the spatial–temporal boundaries between video objects are required for annotating visual content with high-level semantics. In this paper, we define spatial–temporal sampling as a unified process of extracting video objects and computing their spatial–temporal boundaries using a learnt video object model. We first provide a computational approach for learning an optimal key-object codebook sequence from a set of training video clips to characterize the semantics of the detected video objects. Then, dynamic programming with the learnt codebook sequence is used to locate the video objects with spatial–temporal boundaries in a test video clip. To verify the performance of the proposed method, a human action detection and recognition system is constructed. Experimental results show that the proposed method gives good performance on several publicly available datasets in terms of detection accuracy and recognition rate.     

360°线性移相器

本文对一种360°移相器线性条件进行了分析。从线性要求出发,求出了对变容管的引线电感及结电容的最大值和最小值的要求。并研制了一个工作于11GHz 的360°移相器,此移相器在11GHz±100MHz 内线性度优于±3.8%,损耗为6.2±0.7dB,移相误差≤±2°。与国外文献[1]、[3]比较,此移相器在性能指标上是优良的,在理论与实际上一致性良好。     

高精度0°～360°步级移相器

本文介绍一种由纯电阻平衡电桥构成的正弦移相器,它能够在0°～360°范围内实现任意移相,其移相精度与信号频率无关.文中导出了任意移相的设计公式和桥臂电阻误差与移相误差的关系;同时,也对移相桥工作条件引入的移相误差进行了分析.     

360°变容管线性调相器

一、引言在环形器的一端装上一变容管可构成一连续的调相器。从环形器第一端进入的功率被第二端的变容器反射,由第三端输出,此输出的相位和幅度取决于变容管的反射系数。当加到变容管上的反向电压改变时,其反射系数值仍然较高而相位发生变化。此调相器所需调制功率很小,并且对调     

Novel 360° 3D Profilometry

A new method of 360° turning 3D shape measurement in which light sectioning and phase shifting techniques are both used is presented in this paper.A sine light field is applied in the projected light stripe ,meanwhile phase shifting technique is used to calculate phase of the light slit.Thereafter wrapped phase distribution of the slit is formed and the unwrapping process will be made by means of the height information based on the light sectioning method.Therefore phase measuring results with better precision can be obtained .At last the target 3D shape data can be produced according to geometric relationships between phases and the object heights.The principles of this method are discussed in detail and experimental results are shown in this paper.     

感受Mirage的360°发声

2007年11月30日在广州白天鹅宾馆,上海Jamo(尊宝)音响有限公司于白天鹅音响唱片大展期间举行了年度媒体见面会,并在会上向各媒体推荐了来自加拿大多伦多的Mirage(米拉奇)音响.     

Gauss–Jordan elimination-based image tampering detection and self-recovery

This paper proposes a novel Gauss–Jordan elimination-based image tampering detection and self-recovery scheme, aiming at dealing with the problem of malicious tampering on digital images. To deal with the copy–move tampering which is challenging because the tampered region may contain the watermark information, we propose the Improved Check Bits Generation algorithm during watermark generation, to generate the check bits for tampering detection. Meanwhile, the recovery bits are reconstructed according to the fundamental of Gauss–Jordan Elimination, for purpose of image contents self-recovery. To improve the accuracy of detection and the quality of recovered images, we propose the Morphological Processing-Based Enhancement method and the Edge Extension preprocessing respectively during and after the tampering detection Finally, the Gauss–JordanElimination-Based Self-Recovery method is proposed to recover the damaged content mathematically on basis of the detected results. By employing the unchanged recovery bits which are embedded in the non-tampered region, the failure in recovery caused by the damaged recovery bits can be completely avoided. A large number of experiments have been conducted to show the very good performance of the proposed scheme. The precision, recall, and F1 score are calculated for evaluation of tampering detection, while the PSNR values are calculated for evaluation of image recovery. The comparisons with the state-of-the-art methods show that the proposed scheme shows the superiorities in terms of imperceptibility, security and recovery capability. The experimental result indicates the average PSNR of recovered image is 44.415dB.     

60°转360°电压空间的SVPWM软件算法

提出了一种电压空间矢量调制的新型软件算法,在该算法中无须进行电压矢量夹角的三角函数运算及扇区判断,只需定义60°电压空间内的矢量运算公式,由程序自动将360°的电压空间矢量运算转化为60°的电压空间矢量运算,该方法简单,容易实现,为CPU节约了大量的空间资源,文章最后给出了其在交流异步电机控制上的实验波形与结果。     

感受Mirage,S360°发声

2007年11月30日在广州白天鹅宾馆,上海Jamo（尊宝）音响有限公司于白天鹅音响唱片大展期间举行了年度媒体见面会,并在会上向各媒体推荐了来自加拿大多伦多的Mirage（米拉奇）音响。见面会上最耀眼的亮点当属Mirage（米拉奇）音响最新推出的Hi—End扬声器360°发声OMD-28落地式扬声器。     

0°～360°双稳态扭曲盒的矩阵寻址

报道了关于双稳态扭曲液晶显示的动态性能和光学性能的研究结果。这种显示器由具有所需表面预倾角的向列液晶层加手性材料组成。其驱动波形的特征能在0°和360°两种光学差异明显的扭曲状态间选择。     

Tracking moving object using Snake’s jump based on image flow

An active contour model, Snake, was developed as a useful segmenting and tracking tool for rigid or non-rigid (i.e. deformable) objects by Kass in 1987. Snake is designed on the basis of Snake energies. Segmenting and tracking can be executed successfully by the process of energy minimization. The ability to contract is an important process for segmenting objects from images, but the contraction forces of Kass’ Snake are dependent on the object’s form. In this research, new contraction energy, independent of the object’s form, is proposed for the better segmentation of objects. Kass’ Snake can be applied to the case of small changes between images because its solutions can be achieved on the basis of variational approach. If a somewhat fast moving object exists in successive images, Kass’ Snake will not operate well because the moving object may have large differences in its position or form, between successive images. Snake’s nodes may fall into the local minima in their motion to the new positions of the target object in next image. When the motion is too large to apply image flow energy to tracking, a jump mode is proposed for solving the problem. The vector used to make Snake’s nodes jump to the new location can be obtained by processing the image flow. The effectiveness of the proposed Snake is confirmed by some simulations.     

X波段360°模拟移相器的设计

介绍了变容管反射式360°模拟移相器的设计,对相位与调制电压的线性关系作了分析。制成的模拟移相器采用计算机辅助设计,使用了超突变结变容管管芯和微波集成电路工艺。在9.3～9.7GHz范围内可获得360°连续可变相移,调相电压20V,线性偏离优于±5％,中心频率上的偏离优于±3％,插入损牦随相位的变化3dB。     

模拟式360°线性移相器原理与应用

介绍了模拟式360°线性移相器的基本原理及优化设计方法,分析和讨论了主要技术指标的物理意义和技术规范.利用优化设计方法设计的360°线性移相器线性度优于±1.77%,工作带宽500 MHz,并在同步移相扫描应用中获得了满意的效果.     

彩色视频脉冲系统中的360°移相器

在彩色电视视频脉冲系统设备中360°移相器是一个基本电路,比如:编码器、同步机、黑场、彩场、色键等都要用到,本文就是从基本原理出发,对这种电路较系统地作出分析的一个尝试。     

360°自由旋转双系统Sailing Y13A

近两年,微软（Microsoft）在正在发力触控操作系统的同时,谷歌（Google）的Android系统正一点点侵占手机和平板市场,消费者们已经习惯于手机的Android系统,但又离不开主流的桌面操作系统Windows,如果有一款双系统的笔记本该有多好啊!有需求就有市场,消费者的福音：海尔（Haier）在8月11日上市了一创新力作产品,这就是海尔Sailing Y13A,它预装了Windows8.1和Android OS V4．4双系统,两个系统满足你双向需求!MI在第一时间拿到了这款笔记本,它到底有哪些创新之处,让我们一起来看看吧。     

Fast Profilometry of 360° Spinning 3D Measurement

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365天,360°的内容安全防护

2006年,IT面临着更多的风险,病毒、木马、间谍软件、网络钓鱼、垃圾邮件等与安全内容相关的问题已经日渐成为影响计算机用户最主要的威胁。对用户而言,在各类安全问题中,最严重和出现频率最高的安全问题均与安全内容相关,其中垃圾邮件继病毒之后上升为第二个严重的安全问题。除了来自外部的威胁外,如何合理使用网络资源并对内部数据进行有效保护,防止员工上网旷工以及不当浏览网页而带来的安全风险,也开始成为许多用户关心的问题。对于企业来讲,邮件安全、即时消息、Web浏览等应用带来的安全问题,也是传统的安全解决方案所不能系统解决的,…     

采购新体验：360°设计整合采购方案

“360°设计整合采购方案”是派睿电子（Premier）为广大电子设计工程师量身打造以设计为导向的全新元器件采购模式。派睿电子旨在通过其特有的翌日到货、无最小订购量和技术支持等服务为电子工程师带来更多的增值服务。