检索结果-内蒙古大学图书馆

Multilevel Characteristic Basis Function Method with ACA for Accelerated Solution of Electrically Large Scattering Problems

引用

Transactions of Nanjing University of Aeronautics and Astronautics 2018年第3期35卷 449-454页

作者： Li Chenlu Sun Yufa Wang Zhonggen Wang Guohua Key Laboratory of Intelligent Computing & Signal Processing Ministry of EducationAnhui University College of Electrical and Information Engineering Anhui University of Science and Technology

The multilevel characteristic basis function method(MLCBFM)with the adaptive cross approximation(ACA)algorithm for accelerated solution of electrically large scattering problems is studied in this *** the conventional MLCBFM based on Foldy-Lax multiple scattering equations,the improvement is only made in the generation of characteristic basis functions(CBFs).However,it does not provide a change in impedance matrix filling and reducing matrix calculation procedure,which is *** reality,all the impedance and reduced matrix of each level of the MLCBFM have low-rank property and can be calculated ***,ACA is used for the efficient generation of two-level CBFs and the fast calculation of reduced matrix in this *** results are given to demonstrate the accuracy and efficiency of the method.

关键词： multilevel characteristic basis function method(MLCBFM) adaptive cross approximation(ACA) characteristic basis functions(CBFs) electromagnetic scattering

来源：评论

学校读者我要写书评

暂无评论

An Anti-Eavesdrop Transmission Scheduling Scheme Based on Maximizing Secrecy Outage Probability in Ad Hoc Networks

引用

China Communications 2016年第1期13卷 176-184页

作者： WANG Yajun LIAO Tongqing WANG Chuanan School of Mathematical and Information Engineering Anhui Science and Technology University Ministry of Educational Key Laboratory of Intelligent Computing and Signal Processing Anhui University

In this paper,we consider a wireless ad hoc network consisting of multiple source nodes transmitting to their respective destinations,where an eavesdropper attempts to intercept their *** propose an optimal transmission scheduling scheme to defend against the eavesdropper,where a source node having the highest secrecy rate is scheduled to access the wireless medium for transmitting to its destination in an opportunistic *** be specific,the secrecy rate between a pair of the source and destination in the presence of an eavesdropper varies temporally due to the wireless fading *** proposed optimal transmission scheduling scheme opportunistically selects a source node with the highest secrecy rate to transmit its data for the sake of maximizing the security of the ad hoc network against eavesdropping *** comparison purposes,we also consider the conventional round-robin scheduling as a benchmark,where multiple source nodes take turns in accessing their shared wireless medium for transmitting to their respective *** derive closed-form secrecy outage probability expressions of both the round-robin scheduling and the proposed optimal scheduling schemes over Rayleigh fading *** results show that the proposed transmission scheduling scheme outperforms the conventional round-robin method in terms of its secrecy outage ***,upon increasing the number of source-destination pairs,the secrecy outage probability of the round-robin scheme keeps unchanged,whereas the secrecy outage performance of the proposed transmission scheduling significantly improves,showing the security benefits of exploiting transmission scheduling for protecting wireless ad hoc networks against eavesdropping.

关键词： transmission scheduling eavesdropping secrecy outage probability secrecy rate rayleigh fading

来源：评论

学校读者我要写书评

暂无评论

Improving whisper intelligibility in noise environment based on joint time frequency analysis

引用

Information Technology Journal 2013年第6期12卷 1089-1097页

作者： Zhou, Jian Wang, Huabin Fang, Xianyong Tao, Liang Zhao, Li Key Laboratory of Intelligent Computing and Signal Processing Ministry of Education Anhui University Heifei 230601 China Key Laboratory of Underwater Acoustic Signal Processing Ministry of Education Southeast University Nanjing 210096 China

A whisper intelligibility enhancement method was proposed based on the Real-valued Discrete Gabor Transform (RDGT) in the joint time frequency domain where the RDGT can change the density of the spectrum through the over sample rate parameter. An optimal logarithmic spectrum estimator was derived based on RDGT coefficients. Experimental results showed that the proposed method improved the intelligibility of enhanced whisper in an adverse noise environment when using a proper over sample rate value. The largest gains in intelligibility were got when the over sample rate value is set to 16 or 32. The proposed method outperforms other four speech enhancement algorithms in terms of intelligibility improvement. The experimental results also implied that the intelligibility performance of the conventional speech enhancement algorithms might be improved when increasing the density of the time-frequency spectrum properly. © 2013 Asian Network for Scientific Information.

关键词： Frequency domain analysis

来源：评论

学校读者我要写书评

暂无评论

Localization Optimization Algorithm of Maximum Likelihood Estimation Based on Received signal Strength 9

Localization Optimization Algorithm of Maximum Likelihood Es...

引用

2017 9th IEEE International Conference on Communication Software and Networks (ICCSN 2017)

作者： Jun Zhu Qiang Chen Jingjing Zhang Key Lab of Intelligent Computing and Signal Processing Ministry of Education School of Electronics and Information Engineering Anhui University

ISBN: (纸本)9781509038237;9781509038220

In this paper, we propose a method to improve localization algorithm of maximum likelihood estimation;the localization scheme relies on the distance threshold. In order to suppress effectively the effects of received signal strength error to node localization precision. This paper presents an indoor localization algorithm based on received signal strength to select anchor nodes. Compared with the traditional localization algorithm, this scenario not only improve the localization accuracy, but also reduce the calculation complexity of nodes. The simulation results show that the average error of the proposed method is less than 0.15 m. Moreover, when there are a large number of anchor nodes, the computational complexity is effectively reduced. Verification result verifies the effectiveness and reliability of the algorithm.

关键词： localization received signal strength(RSS) maximum likelihood estimation(MLE) least squares threshold

来源：评论

学校读者我要写书评

暂无评论

A Direct-Path Interference Cancellation Approach to Passive Radar Based on Adaptive Fractional Delay Estimation

引用

电子学报(英文版) 2007年第2期16卷 359-362页

作者： ZHU Jiabing WU Xianliang TAO Liang HONG Yi Education Ministry Key Laboratory of Intelligent Computing and Signal Processing Anhui University Hefei 230039 China Institute of Signal Processing East China Research Institute of Electronic Engineering Hefei 230031 China

Target detection by non-cooperative illuminator is a study hotspot in electronic warfare field, with'four countering' potential advantages for passive radar. One of the major problems in continuous wave bistatic radar is Direct path interference (DPI). Conventional solutions to this problem is the use of an adaptive antenna, steering null towards the interference. Unfortunately the null depth obtained by this technology is not enough for surveillance radar. First of all, DPI appeared in passive radar based on non-cooperative FM broadcast transmitter is analyzed in this paper. Secondly, a DPI cancellation based on Adaptive fractional delay estimation (AFDE) is in detail introduced how to deal with this problem. Finally, a passive radar experimental system based on non-cooperative FM broadcast transmitter is provided, simulation results by real collected data show applying the method proposed in this paper is effective in suppression DPI.

关键词：无源雷达直达波干扰对消自适应分数延迟估计 FM广播

来源：评论

学校读者我要写书评

暂无评论

Speaker Recognition Based on the Improved Double-Threshold Endpoint Algorithm and Multistage Vector Quantization 9

Speaker Recognition Based on the Improved Double-Threshold E...

引用

2017 9th IEEE International Conference on Communication Software and Networks (ICCSN 2017)

作者： Jun Zhu Jingjing Zhang Qiang Chen Peipei Tu Key Lab of Intelligent Computing and Signal Processing Ministry of Education School of Electronics and Information Engineering Anhui University

ISBN: (纸本)9781509038237;9781509038220

The traditional double-threshold endpoint detection method has the phenomenon of missing detection. Therefore, the speech recognition(SR) system based on vector quantization(VQ) in this paper proposes an improved algorithm for this phenomenon, which effectively avoids the problem of missing detection. Then, Mel Frequency Cepstral Coefficients(MFCC) is used to extract the characteristic parameters of the speech signal, and the multistage vector quantization is used to quantify the characteristic parameters. Experimental results show that, the proposed algorithm improves the recognition rate of the text-independent speaker recognition system by 8.7%, and it also confirms that the longer the training speech is, the higher the recognition rate will be.

关键词： the multistage vector quantization MFCC double-threshold endpoint detection method missing detection characteristic parameters

来源：评论

学校读者我要写书评

暂无评论

An image enhancement method based on improved fuzzy set

引用

Revista Tecnica de la Facultad de Ingenieria Universidad del Zulia 2016年第9期39卷 161-169页

作者： Chen, Lili Guo, Hongjun Laboratory of Intelligent Information Processing Suzhou University Suzhou Anhui234000 China Key Laboratory of Intelligent Computing and Signal Processing of MOE Anhui University Hefei Anhui230039 China

At present, in related image processing field, the fuzzy set theory has also gained more successful applications to some extent. The image processing based on the fuzzy theory is an important research area. The information loss brought by 3D object projection in 2D image plane makes the image have the ambiguity exist in essence, thus there exists ambiguity when defining image characteristics such as the border, area and texture, therefore, because of the complexity of the image itself, uncertainty and inaccuracy or ambiguity may occur in the different stages of the processing. The algorithm in this paper improves the degree of membership function to make it suitable for the image fuzzy enhancement. The membership function curve is S-shaped, and at the inflection point, the function value on the left side drops rapidly while the function value on the right side rapidly rises. There is certain symmetry about the inflection point, and the function inflection point position can be decided by changing function parameters, and better enhancement effect can be gained by a small amount of iteration. By the experimental simulation, it is verified that the enhanced color image by adopting the method in this paper is bright in color on the visual effect with moderate increasing proportion of brightness and contrast, and best color maintaining performance and minimum chromaticity change, and also the image information entropy is improved when compared with the original image data.

关键词： Image processing

来源：评论

学校读者我要写书评

暂无评论

Study on moving target detection to passive radar based on FM broadcast transmitter

引用

Journal of Systems Engineering and Electronics 2007年第3期18卷 462-468页

作者： Zhu Jiabing Tao Liang Hong yi Education Ministry Key Lab of Intelligent Computing and Signal Processing Anhui Univ. Hefei 230039 P. R. China Inst. of Signal Processing East China Research Inst. of Electronic Engineering Hefei 230031 P. R. China

Target detection by a noncooperative illuminator is a topic of general interest in the electronic warfare field. First of all, direct-path interference （DPI） suppression which is the technique of bottleneck of moving target detection by a noncooperative frequency modulation（FM） broadcast transmitter is analyzed in this article; Secondly, a space-time-frequency domain synthetic solution to this problem is introduced： Adaptive nulling array processing is considered in the space domain, DPI cancellation based on adaptive fractional delay interpolation （AFDI） technique is used in planned time domain, and long-time coherent integration is utilized in the frequency domain; Finaily, an experimental system is planned by considering FM broadcast transmitter as a noncooperative illuminator, Simulation results by real collected data show that the proposed method has a better performance of moving target detection.

关键词： passive radar direct path interference adaptive beamforming adaptive fractional delay interpolation,long-time coherent integration.

来源：评论

学校读者我要写书评

暂无评论

Fusion of infrared and visible images using nonsubsampled shearlet transform and block-based random image sampling

引用

Revista Tecnica de la Facultad de Ingenieria Universidad del Zulia 2016年第7期39卷 337-347页

This paper presents a novel image fusion method based on nonsubsampled shearlet transform (NSST) and block-based random image sampling for infrared and visible images. In the method, the NSST is firstly performed on each of the source images to obtain their low frequency and high frequency subbands coefficients. Then the low frequency coefficients are fused by combing the block-based random image sampling and the sliding widow technique, while the high frequency coefficients are fused using classical absolute value maximum choosing rule. The fused image is reconstructed though performing the inverse NSST. The experiments are carried out on five pairs of infrared and visible images using five traditional fusion methods to verify the effectiveness and efficiency of the proposed method and by comparing the fused results visually and objectively it is demonstrated that the proposed fusion method is competitive or even superior to the other wellknown methods.

关键词： Image fusion

来源：评论

学校读者我要写书评

暂无评论

Efficient multi-resolution detection of binary object

引用

Information Technology Journal 2010年第8期9卷 1641-1646页

作者： Fang, Xianyong Wu, Hao MOE Key Laboratory of Intelligent Computing and Signal Processing School of Computer Science and Technology Anhui University Anhui 230039 China

This study presents an efficient multi-resolution method to detect binary object directly. Both intensity and geometry differences are used to measure the similarity between the source object template and target objects inside the test image. Especially for the geometrical difference, the histogram of oriented gradients is proposed to measure the similarity of the edge images between the source object template and the target object. Based on these two measurements, a multi-resolution strategy is used to accurately locate the object position in a coarse-to-fine way, where intensity difference and geometry difference applied consequently in each layer. Experimental results demonstrate the efficiency of the proposed method. © 2010 Asian Network for Scientific Information.

关键词： Geometry

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：