检索结果-南通市图书馆

THz-TDS signal analysis and substance identification via the conformal split

Science china(information Sciences) 2012年第1期55卷 49-63页

作者： XIE WeiXin1,2,LI Jing1,2&PEI JiHong2 1School of Electronic Engineering,Xidian university,Xi'an 710071,china 2intelligent information institute,shenzhen university,shenzhen 518060,china School of Electronic Engineering Xidian University Xi’an China intelligent information institute Shenzhen University Shenzhen China

A terahertz time-domain spectroscopy(THz-TDS)imaging system can obtain high-dimensional signals with substance fingerprint *** introducing geometric algebra,a novel signal analysis approach to THz-TDS signals is developed based on an optical physical *** this approach,signals are represented with vectors in the high-dimensional real vector *** distribution properties and algebraic relationships of THz-TDS signals are *** is proved that every complex refractive index of substances relates to a unique 2-blade,the vectors corresponding to the samples of the same substance are collinear and belong to the intrinsic 2-blade of the *** decomposed through the conformal split with respect to a 2-blade,THz-TDS signals of high dimensionality can be related to vectors in a 2-dimensional *** on the conformal split properties we deduced,two criteria for substance identification on the basis of THz-TDS signals are ***,a novel substance identification method via the conformal split is *** the method,the 2-blade related to each "known" substance is calculated with two vectors corresponding to THz-TDS signals measured from samples of the substance but with dierent *** the conformal split with respect to those 2-blades,an identified vector corresponding to a THz-TDS signal is linearly related to the vector in a 2-dimensional *** substance of a sample can be identified using criteria on the projected vectors in the *** method can contribute to accurate classification and ***,two experiments are presented that show the feasibility and accuracy of this method.

关键词： terahertz time-domain spectroscopy substance identification geometric algebra conformal split

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Multispectral image edge detection via Clifford gradient

引用

Science china(information Sciences) 2012年第2期55卷 260-269页

作者： XU Chen2,LIU Hui1,CAO WenMing1 & FENG JiQiang2 1College of information Engineering,shenzhen university,shenzhen 518060,china 2institute of intelligent Computing Science,shenzhen university,shenzhen 518060,china institute of intelligent Computing Science Shenzhen University Shenzhen China College of information Engineering Shenzhen University Shenzhen China

The edge detection of a multispectral image with a mass of image information is theoretically expected to give a more accurate *** algebra is more suitable for processing multidimensional data and expressing the data association than general ***,the basic properties of Clifford algebra are ***,the Clifford algebra description of a multispectral image is ***,a novel multispectral image edge detection algorithm is proposed in terms of the Clifford *** the first two experiments,comparison of the detail achieved by the new algorithm with that from the maximal entropy edge detection algorithm reveals that the edge detection based on Clifford gradient is better at retaining and identifying edge information of the multispectral image than the maximal entropy edge detection *** experiments using tuberculosis CT image show that the new algorithm has clinical value in reducing risk of misdiagnosis.

关键词： multispectral image edge detection Clifford gradient

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Power minimization with derivative constraints for high dynamic GPS interference suppression

引用

Science china(information Sciences) 2012年第4期55卷 857-866页

作者： WU RenBiao 1,2,LI Chan 1 & LU Dan 1 1 Tianjin Key Laboratory for Advanced Signal Processing,Civil Aviation university of china,Tianjin 300300,china 2 intelligent information institute of ATR Lab,shenzhen university,shenzhen,518060,china Tianjin Key Laboratory for Advanced Signal Processing Civil Aviation University of China Tianjin China intelligent information institute of ATR Lab Shenzhen University Shenzhen China

In this paper,a novel adaptive interference suppression algorithm is proposed for high dynamic GPS (global positioning system) *** new method incorporates derivative constraints on the inter-ference DOA (direction of arrival) into power minimization approach,which could broaden the width of nulls in the interferences directions and adapt to the rapid change of the interference *** with the traditional wide nulling algorithm based on the derivative constraints,the new method does not have to know or estimate the DOAs of the desired signal and the *** new method is firstly discussed in the context of spatial processing,and then extended to space-time adaptive processing to mitigate wideband diffusive multipath *** of the new method is verified via simulation examples.

关键词： GPS interference cancellation adaptive arrays space-time adaptive processing high dynamic GPS receiver

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

A novel STAP method for the detection of fast air moving targets from high speed platform

引用

Science china(information Sciences) 2012年第6期55卷 1259-1269页

作者： WU RenBiao 1,2,JIA QiongQiong 1 & LI Hai 1 1 Tianjin Key Laboratory for Advanced Signal Processing,Civil Aviation university of china,Tianjin 300300,china 2 intelligent information institute of ATR Lab,shenzhen university,shenzhen 518060,china Tianjin Key Laboratory for Advanced Signal Processing Civil Aviation University of China Tianjin China intelligent information institute of ATR Lab Shenzhen University Shenzhen China

Space-time adaptive processing (STAP) is an effective method for detecting moving target in airborne/spaceborne ***,the detection of fast air moving targets from high speed platform is challenged by the range walk of both the clutter and moving *** is well known that keystone formatting can be used to compensate for the range walk of multiple moving targets simultaneously without using the knowledge of the motion ***,in the presence of serious Doppler ambiguity of fast air moving targets,distribution of the clutter will be affected by the keystone formatting matched to the ambiguity number of targets,and as a result the STAP performance will *** this paper,a novel STAP method is proposed for the detection of fast air moving targets from high speed platform,which can deal with the range walk of both clutter and *** of the new method is verified via simulation examples.

关键词： airborne/spaceborne radar keystone formatting space-time adaptive processing (STAP) moving target detection

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Image corner detection using topology learning

引用

The Journal of china Universities of Posts and Telecommunications 2010年第6期17卷 101-105页

作者： SUN Wei,YANG Xuan College of Computer Science and Software Engineering,shenzhen university,shenzhen 518060,china College of Computer Science and Software Engineering Shenzhen University Shenzhen 518060 China

Image corner detection plays an important role in image analysis and recognition. This paper presents a novel corner detector based on the growing neural gas （GNG） network and this proposed detector is called GNG-C. With the GNG network,image topology information can be learned and used to implement corner detection. The GNG-C approach can be described as consisting of the following steps. First,a canny edge detector is used to acquire the contour information of the input image. This edge information is used to train a modified GNG network. A special stopping criterion is defined to terminate network learning. Second,vectors formed between network nodes and their neighbors are used to measure curvatures. Third,dynamic regions of support （ROS） are determined based on these curvatures. These ROS are used to suppress curvature noise. The curvature values of the nodes are then analyzed to estimate the candidate corners. Finally,the candidates are distilled by a non-maxima suppression process to obtain the final set of corners. Experiments on both artificial and real images show that the proposed corner detection method is feasible and effective.

关键词： corner detection GNG topology learning self-organizing map

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Approximation algorithm for minimizing relay node placement in wireless sensor networks

引用

Science china(information Sciences) 2010年第11期53卷 2332-2342页

作者： LU KeZhong1,2, CHEN GuoLiang1,2, FENG YuHong1,2, LIU Gang1,2 & MAO Rui1,2 1College of Computer Science and Software Engineering, shenzhen university, shenzhen 518060, china 2National High Performance Computing Center at shenzhen, shenzhen 518060, china College of Computer Science and Software Engineering Shenzhen University Shenzhen China National High Performance Computing Center at shenzhen Shenzhen China

To eliminate the routing load unbalance among sensor nodes, one approach is to deploy a small number of powerful relay nodes acting as routing nodes in wireless sensor networks, the major optimization objective of which is to minimize the number of relay nodes required. In this paper, we prove that the relay node placement problem in a bounded plane is a P problem, but its computational complexity in general case is quite great. From the geometric cover feature of the relay node placement problem, an O(n2 log n) time greedy approximation algorithm is proposed, where n is the number of sensor nodes. Particularly, at each stage of this algorithm's iterative process, we first select a critical node from uncovered sensor nodes, and then determine the location of relay node based on the principle of preferring to cover the sensor node closer to the critical node, so as to prevent the emergence of isolated node. Experiment results indicate that our proposed algorithm can generate a near optimum feasible relay node deployment in a very short time, and it outperforms existing algorithms in terms of both the size of relay node deployment and the execution time.

关键词： wireless sensor network relay node placement geometrical cover approximation algorithm greedy algorithm

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Positioning localities from spatial assertions based on Voronoi neighboring

引用

Science china(Technological Sciences) 2010年第S1期53卷 143-149页

作者： GONG YongXi 1,2,3,LI GuiCai 1,LIU Yu 2 & YANG Jian 1 1 shenzhen Key Lab of Recycling Economy,Peking university shenzhen Graduate School,shenzhen 518055,china 2institute of Remote Sensing and Geographical information Systems,Peking university,Beijing 100871,china 3College of Urban and Environmental Science,Peking university,Beijing 100871,china shenzhen Key Lab of Recycling Economy Peking University Shenzhen Graduate School Shenzhen China institute of Remote Sensing and Geographical information Systems Peking University Beijing China College of Urban and Environmental Science Peking University Beijing China

With the rapid development of Internet,much spatial information contained in non-structured or semi-structured documents is available on the World Wide *** such documents,localities are always textually described using spatial relationships and named places,instead of numerical ***,extracting positional information from locality descriptions is an important *** this paper,we bridge two aspects of locality descriptions,namely generating locality descriptions and positioning localities,and provide a method to compute probability density according to the selection probability of a reference object to describe the position of the target *** operation on uncertainty field is used to deal with locality description involving multiple reference *** metrics are introduced to measure the results of positioning *** choose the mixed selection probability function based on Euclidean distance and Voronoi stolen-area to compute probability density ***,we use three cases to demonstrate the proposed methods.

关键词： geographic information science positioning locality Voronoi neighboring probability density function

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

H2 /H∞ control of networked control system with random time delays

引用

Science china(information Sciences) 2011年第12期54卷 2635-2650页

作者： QIU Li 1,2 , XU BuGong 1 & LI ShanBin 1 1 College of Automation Science and Engineering, South china university of Technology, Guangzhou 510640, china 2 College of Mechatronics and Control Engineering, shenzhen university, shenzhen 518060, china College of Automation Science and Engineering South China University of Technology Guangzhou China College of Mechatronics and Control Engineering Shenzhen University Shenzhen China

This paper investigates the H 2 /H ∞ control problem for a class of discrete-time networked control systems with random communication time delays. Both sensor-to-controller (S-C) and controller-to-actuator (C-A) random network-induced delays are considered. Two independent Markov chains are used to model the S-C and C-A random delays. The resulting closed-loop system is a jump linear time-delay system induced by two Markov chains. Sufficient conditions for existence of H 2 /H ∞ controller are established by free-weighting matrix and stochastic Lyapunov functions. A simulation example illustrates the effectiveness of the proposed method.

关键词： H 2 /H ∞ control networked control systems Markov chains random time delays

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

An oblivious fragile watermarking scheme for images utilizing edge transitions in BTC bitmaps

引用

Science china(information Sciences) 2012年第11期55卷 2570-2581页

作者： ZHANG Yong1,LU ZheMing2 & ZHAO DongNing1 1ATR National Defense Technology Key Laboratory,College of information Engineering,shenzhen university,shenzhen 518060,china 2School of Aeronautics and Astronautics,Zhejiang university,Hangzhou 310027,china ATR National Defense Technology Key Laboratory College of Information Engineering Shenzhen University Shenzhen China School of Aeronautics and Astronautics Zhejiang University Hangzhou China

As one of the famous block-based image coding schemes,block truncation coding(BTC) has been also applied in digital *** BTC-based watermarking or hiding schemes usually embed secret data by modifying the BTC encoding stage or BTC-compressed data,obtaining the watermarked image with poorer quality than the BTC-compressed *** paper presents a new oblivious image watermarking scheme by exploiting BTC *** the traditional schemes,our approach does not really perform the BTC compression on images during the embedding process but utilizes the parity of the number of horizontal edge transitions in each BTC bitmap to guide the watermark embedding and extraction *** embedding process starts by partitioning the original cover image into non-overlapping 4×4 blocks and performing BTC on each block to obtain its BTC *** watermark bit is embedded in each block by modifying at most three pixel values in the block to make sure that the parity of the number of horizontal edge transitions in the bitmap of the modified block is equal to the embedded watermark *** the extraction stage,the suspicious image is first partitioned into non-overlapping 4×4 blocks and BTC is performed on each block to obtain its ***,by checking the parity of the number of horizontal edge transitions in the bitmap,we can extract one watermark bit in each *** results demonstrate that the proposed watermarking scheme is fragile to various image processing operations while keeping the transparency very well.

关键词： fragile image watermarking oblivious watermarking block truncation coding data hiding image authentication

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Time amplifying techniques towards atomic time resolution

引用

Science china(Technological Sciences) 2009年第12期52卷 3425-3446页

作者： LI JingZhen institute of Photonic Engineering,College of Electron Science&Technology,shenzhen university,and shenzhen Key Laboratory of Micro·Nano Photonic information,shenzhen 518060,china institute of Photonic Engineering College of Electron Science & Technology Shenzhen University and Shenzhen Key Laboratory of Micro-Nano Photonic Information Shenzhen China

High speed imaging technology has opened applications in many fields,such as collision,detonating, high voltage discharge,disintegration and transfer of phonon and exciton in solid,photosynthesis primitive reaction,and electron dynamics inside atom *** principle,all of the transient processes need to be explained theoretically and,at the same time,the time amplifying technique is required for observations of these *** present review concerns the atomic time amplifying mechanism of optical information and the extremely-high speed imaging methods,which are expressed in terms of the short time amplifying *** is well-known that for extremely-high speed imaging with the converter tube,the temporal resolution is in the order of sub-picosecond of the streak imaging,and the imaging frequency is 6×10 8 ―5×10 9 fps(frame per second)of the frame *** the other hand,for the tubeless extremely-high speed imaging,the imaging frequency is 10 7 ―10 14 fps,and its mechanism of forming high speed and framing could involve a lot of factors of the light under investigation,for instance,light speed,light parallelism,the parameters of light wave such as amplitude,phase,polari- zation and wavelength,and even quantum properties of *** the cascaded system of electro- magnetic wave and particle wave,it is possible to simultaneously realize extremely-high resolution in time and space,which is higher than a kite *** it would be possible to break the limit of the Heisenberg uncertainty relation of the optical frequency band.

关键词： time amplification image converter tube imaging tubeless imaging ultra-high speed imaging extremely-high speed imaging holog- raphic coherent shutter optical acceleration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

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

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

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：