检索结果-内蒙古大学图书馆

Maxwell'S equations, symplectic matrix, and grid

Progress In Electromagnetics Research B 2008年 8卷 115-127页

作者： Sha, W. Wu, X.L. Huang, Z.X. Chen, M.S. Department of Electrical and Electronic Engineering The University of Hong Kong Pokfulam Road Hong Kong Key Laboratory of Intelligent Computing and Signal Processing Anhui University Feixi Road 3 Hefei230039 China Department of Physics and Electronic Engineering Hefei Teachers College Jinzhai Road 327 Hefei230061 China

The connections between Maxwell's equations and symplectic matrix are studied. First, we analyze the continuous-time Maxwell's differential equations in free space and verify its time evolution matrix (TEMA) is symplectic-unitary matrix for complex space or symplectic-orthogonal matrix for real space. Second, the spatial differential operators are discretized by pseudo-spectral (PS) approach with collocated grid and by finite-difference (FD) method with staggered grid. For the PS approach, the TEMA conserves the symplectic-unitary property. For the FD method, the TEMA conserves the symplectic-orthogonal property. Finally, symplectic integration scheme is used in the time direction. In particular, we find the symplectiness of the TEMA also can be conserved. The mathematical proofs presented are helpful for further numerical study of symplectic schemes. © 2008, Electromagnetics Academy.

关键词： Matrix algebra

来源：评论

学校读者我要写书评

暂无评论

Spatial-temporal attention analysis for home video

Spatial-temporal attention analysis for home video

引用

IEEE International Conference on Multimedia and Expo (ICME)

作者： Xuekan Qiu Shuqiang Jiang Huiying Liu Qingming Huang Longbing Cao Chinese Academy of Sciences Beijing China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy and Sciences Beijing China Sydney University of Technology Sydney Australia

In this paper, by considering the multiple spatial-temporal characteristic of visual perception system, we propose a novel home video attention analysis method. Firstly, each frame of the video is segmented into regions which are more informative than pixels and image blocks. Then the saliency of each region is analyzed by combining static, motion and location attentions. Finally a region based saliency map is generated for each frame, and an attention score curve is obtained for the video clip by combining attention scores of all regions in each frame. Both of them can be utilized in wide applications. This method takes advantage of the properties of human visual perception and can well present the attention information of home videos. Experimental results show the effectiveness of this approach.

关键词： Cameras Image segmentation Multimedia communication Multimedia systems Streaming media Pixel Visualization

来源：评论

学校读者我要写书评

暂无评论

Optimized symplectic scheme for electromagnetic simulations

Optimized symplectic scheme for electromagnetic simulations

引用

Asia-Pacific Conference on Microwave

作者： Bo Wu Zhi-Xiang Huang Wei Sha Ming-Sheng Chen Hong Dai School of physical science and technology Yunnan University China Key Laboratory of Intelligent Computing & Signal Processing Anhui University China Department of Electrical and Electronic Engineering University of Hong Kong Hong Kong China Department of Physics and Electronic Engineering Hefei Teachers College China

Classical finite-difference time-domain (FDTD) method has been widely used in computational electromagnetics, but for electrically large domains and for late-time analysis, FDTD method begins to show its limitations due to the accumulation of phase errors. To solve this problem, several methods have been proposed such as high-order schemes and four-stage Runge-Kutta integrator. Recently, the symplectic methods have been adopted for using in computational electromagnetics. In this paper, the concentration is on the derivation of an optimized fourth-order symplectic scheme in electromagnetic simulations.

关键词： Computational modeling Finite difference methods Permittivity Permeability Maxwell equations Electromagnetic propagation Differential equations Optimization methods Physics computing signal processing

来源：评论

学校读者我要写书评

暂无评论

Coarse-to-fine video text detection

Coarse-to-fine video text detection

引用

IEEE International Conference on Multimedia and Expo (ICME)

作者： Guangyi Miao Qingming Huang Shuqiang Jiang Wen Gao Chinese Academy of Sciences Beijing China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy and Sciences Beijing China Institute of Digital Media Peking University Beijing China

In this paper, we propose an effective coarse-to-fine algorithm to detect text in video. Firstly, in coarse-detection section, stroke filter is employed to detect all candidate stroke pixels, and then a fast region growing method is developed to connect these pixels into regions which are further separated into candidate text lines by projection operation. Secondly, in fine-detection section, correct text regions are selected from candidate ones by support vector machine (SVM) model and stroke features, and text regions in multi-resolution are integrated. Finally, the result is optimized significantly according to temporal correlation information. Experimental results show that our algorithm achieves real-time performance and is robust for the variation of language, font, size, color and noise of text caused by low frame resolution in video.

关键词： Pixel Support vector machines Feature extraction Classification algorithms Filtering algorithms Streaming media Correlation

来源：评论

学校读者我要写书评

暂无评论

Illumination transfer using homomorphic wavelet filtering and its application to light-insensitive face recognition

Illumination transfer using homomorphic wavelet filtering an...

引用

International Conference on Automatic Face and Gesture Recognition

作者： Hu Han Shiguang Shan Xilin Chen Wen Gao Key Laboratory of Intelligent Information Processing of CAS Institute of Computing Technology Chinese Academy of Sciences Beijing China Chinese Academy of Sciences Beijing China Institute of Digital Media Peking University Beijing China

In this paper, we propose a novel homomorphic wavelet filtering based illumination transfer technique to change the dominant lighting of one face image (source face image) to another face image (reference face image ). Specifically, in the proposed method, based on the ldquoreflectance-illuminationrdquo imaging model, we first obtain an approximate estimate of the illumination component of the face image through a wavelet-based Multiresolution Analysis (MRA) in the logarithm domain of the input image. Then, a homomorphic filtering procedure is applied to improve the accuracy of the illumination component estimation. Finally, the source face image is re-lighted by substituting the estimated illumination component of the reference image for that of the source image. The proposed method is entirely an image processing based method without any 3D geometry modeling steps, so it is simple but effective. The method is also applied easily to illumination invariant face recognition by transferring a standard illumination to all the face images. Experimental results show that our method is quite effective for both illumination transfer and illumination-insensitive face recognition.

关键词： Lighting Filtering Face recognition Solid modeling Geometry Face detection Facial animation Multiresolution analysis Image processing Digital filters

来源：评论

学校读者我要写书评

暂无评论

An Improved Adaptive Exponential Smoothing Model for Short-term Travel Time Forecasting of Urban Arterial Street

引用

自动化学报 2008年第11期34卷 1404-1409页

作者： LI Zhi-Peng YU Hong LIU Yun-Cai LIU Fu-Qiang Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 200092 P.R. China Intelligent Transportation System Department Shanghai Electrical Apparatus Research Institute Shanghai 200063 P. R. China Institute of Image Processing and Pattern Recognition Shanghai Jiao Tong University Shanghai 200240 P. R. China

旅行时间的短期的预报为聪明的交通系统的成功是必要的。在这份报纸，我们考察预报模型的短期的交通的 state-of-art 并且构画出他们每个模型的基本想法，相关工作，优点和劣势。一改进适应指数的变光滑(IAES ) 模型也被建议克服以前的... 详细信息

旅行时间的短期的预报为聪明的交通系统的成功是必要的。在这份报纸，我们考察预报模型的短期的交通的 state-of-art 并且构画出他们每个模型的基本想法，相关工作，优点和劣势。一改进适应指数的变光滑(IAES ) 模型也被建议克服以前的适应指数的变光滑模型的缺点。然后，比较实验在状况和反常交通调节评估在牌照匹配获得的直接旅行时间数据(每分钟行数) 上预报模型的四个主要分支的性能的正常交通下面被执行。实验的结果证明每个模型似乎有它的自己的力量和软弱。IASE 的预报表演比在更突然预报地平线(预报的和二步) 的另外的模型优异， IASE 能够处理各种交通条件。

关键词：自适应指数平滑模型短期旅行时间预测预测方法信息处理技术城市街道设计方案

来源：评论

学校读者我要写书评

暂无评论

Mahalanobis distance based Polynomial Segment Model for Chinese Sign Language Recogniton

Mahalanobis distance based Polynomial Segment Model for Chin...

引用

IEEE International Conference on Multimedia and Expo (ICME)

作者： Yu Zhou Xilin Chen Debin Zhao Hongxun Yao Wen Gao School of Computer Science and Technology Harbin Institute of Technology Harbin China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy and Sciences Beijing China Institute of Digital Media Peking University Beijing China

Sign Language Recognition (SLR) systems are mostly based on Hidden Markov Model (HMM) and have achieved excellent results. However, the assumption of frame independence in HMM makes it inconsistent with the characteristic of strong temporal correlation in sign language signals. Polynomial Segment Model (PSM) explicitly represents the temporal evolution of sign language features as a Gaussian process with time-varying parameters. In this paper PSM is first introduced to SLR framework to solve the temporal correlation problem. Considering the correlation among the coefficients of polynomial trajectorypsilas different orders, Mahalanobis distance is used as the classification criterion to evaluate the likelihood of test data. Experimental results show that our method outperform the conventional HMM methods by 6.81% in recognition accuracy.

关键词： Hidden Markov models Handicapped aids Distance measurement Trajectory Vocabulary Euclidean distance Polynomials

来源：评论

学校读者我要写书评

暂无评论

An Innovative Tempo Model for Movie Content Analysis

An Innovative Tempo Model for Movie Content Analysis

引用

IEEE International Conference on Networking, Sensing and Control

作者： Anan Liu Zhaoxuan Yang Jiapeng Wu Yongdong Zhang Jintao Li School ofElectronic Engineering Tianjin University TJU Tianjin China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy and Sciences Beijing China Tianjin University TJU China ICT Chinese Academy and Sciences China

The paper presents a novel tempo model for movie content analysis. We originally propose that tempo indicates the rhythm of both movie scenarios and human perception and focus on the low level features extraction to represent both aspects. By thoroughly analyzing them, we classify the factors of tempo into two sorts. The first is based on the film grammar and we use the low level features of shot length and camera motion to describe filmmaking by directors. The second is based on the human perception and the low level features of motion intensity, motion complexity, audio energy and audio pace are integrated for the formulation of information to describe the viewers' emotional changes to continuously developing storyline. With both factors, tempo is defined and tempo flow plot is derived as the clue of storyline. Then we implement the tempo model for Action scene detection and build a system, SmartMovirPlayer, for hierarchical browse and edit with action concept annotation. The large-scale experiments demonstrate the effectiveness of the tempo model for movie content analysis.

关键词： Motion pictures Humans Layout Performance analysis Rhythm Feature extraction Cameras Large-scale systems Technology planning Laboratories

来源：评论

学校读者我要写书评

暂无评论

Image segmentation using dynamic mechanism based PCNN model

Image segmentation using dynamic mechanism based PCNN model

引用

International Joint Conference on Neural Networks (IJCNN)

作者： Yuanhua Qiao Jun Miao Lijuan Duan Yunfeng Lu College of Applied Science Beijing University of Technology Beijing China Institute of Computing Technology and the Key Laboratory of Intelligent Information Processing Chinese Academy and Sciences Beijing China College of Computer Science and Technology Beijing University of Technology Beijing China

Pulse-coupled neuron networks (PCNN) can be efficiently applied to image segmentation. However, the performance of segmentation depends on the suitable PCNN parameters, which are obtained by manual experiment, and the effect of the segmentation needs to be improved for images with noise. In this paper, dynamic mechanism based PCNN(DMPCNN) is brought forward to simulate the integrate-and-fire mechanism, and it is applied to segment images with noise effectively. Parameter selection is based on dynamic mechanism. Experimental results for image segmentation show its validity and robustness.

关键词： Neurons Image segmentation Couplings Mathematical model Equations Fires Artificial neural networks

来源：评论

学校读者我要写书评

暂无评论

Parzen Discriminant Analysis

Parzen Discriminant Analysis

引用

International Conference on Pattern Recognition

作者： Youhan Fang Shiguang Shan Hong Chang Xilin Chen Wen Gao Chinese Academy of Sciences Beijing China Digital Media Research Center Institute of Computing Technology Chinese Academy of Sciences Beijing China Key Laboratory of Intelligent Information Processing CAS Beijing China Digital Media Institute Peking University Beijing China

ISBN: (纸本)9781424421749

In this paper, we propose a non-parametric discriminant analysis method (no assumption on the distributions of classes), called Parzen discriminant analysis (PDA). Through a deep investigation on the non-parametric density estimation, we find that minimizing/maximizing the distances between each data sample and its nearby similar/dissimilar samples is equivalent to minimizing an upper bound of the Bayesian error rate. Based on this theoretical analysis, we define our criterion as maximizing the average local dissimilarity scatter with respect to a fixed average local similarity scatter. All local scatters are calculated in fixed size local regions, resembling the idea of Parzen estimation. Experiments in UCI machine learning database show that our method impressively outperforms other related neighbor based non-parametric methods.

关键词： Error analysis Scattering Upper bound Linear discriminant analysis Information analysis Bayesian methods Gaussian distribution Personal digital assistants Content addressable storage Performance analysis

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：