检索结果-内蒙古大学图书馆

21st Telecommunications Forum (TELFOR)

作者： Voicu, C. Lohan, E. S. Halunga, S. Univ Politehn Bucuresti Telecommun Dept Elect Telecommun & Informat Technol Fac Bul Iuliu Maniu 1-3 Bucharest 061071 Romania Tampere Univ Technol Dept Elect & Commun Engn Tampere 33101 Finland

ISBN: (纸本)9781479914203

This paper presents the results obtained by a new multiuser detector based on the Projection Onto Convex Sets (pocs) deconvolution algorithm, in comparison with those obtained by the decorrelating detector, when the channel is affected by the flat Rayleigh fading and gray images are transmitted through the system. All the users transmit their information with the same power, but the spreading codes are correlated. We will investigate the fading effect on the received images and the impact of the crosscorrelation of the spreading codes on the quality of the received images. In the end, several conclusions are highlighted, with respect to the level of performance achieved.

关键词： Decorrelating detector pocs algorithm image transmission space-time block coding universal image quality index visual information fidelity index

来源：评论

学校读者我要写书评

暂无评论

Multiuser detection in DS-CDMA systems using pocs algorithm

Multiuser detection in DS-CDMA systems using POCS algorithm

引用

Telecommunications Forum Telfor

作者： C. Voicu E. S. Lohan S. Halunga Telecommunication Department Electronics Telecommunications & Information Technology Faculty University "Politehnica" of Bucharest Department of Electronics and Communications Engineering Tampere University of Technology

ISBN: (纸本)9781479914180

This paper presents the results obtained by a new multiuser detector based on the Projection Onto Convex Sets (pocs) deconvolution algorithm, in comparison with those obtained by the decorrelating detector, when the channel is affected by the flat Rayleigh fading and gray images are transmitted through the system. All the users transmit their information with the same power, but the spreading codes are correlated. We will investigate the fading effect on the received images and the impact of the cross-correlation of the spreading codes on the quality of the received images. In the end, several conclusions are highlighted, with respect to the level of performance achieved.

关键词： Decorrelating detector pocs algorithm Image transmission Space-time block coding Universal image quality index Visual information fidelity index

来源：评论

学校读者我要写书评

暂无评论

Super-Resolution Image Reconstruction for Omni-Vision based on pocs

Super-Resolution Image Reconstruction for Omni-Vision based ...

引用

21st Chinese Control and Decision Conference

作者： Zhang Fan Zhu Qi-dan Harbin Engn Univ Acad Automat Harbin 150001 Peoples R China

ISBN: (纸本)9781424427239

The catadioptric omnidirectional sensor, called Omni-Vision, involving capture and automatic interpretation of images, depicts full horizontal panorama 360 degrees view of the surroundings. The field of view band can be easily transformed to a panoramic image and a converntional perspective image. However, it has an intrinsical disadvantage that the angular resolution Omni-Vision is lower than that of conventional video camera. In this paper, a super-resolution method for the Omni-Vision is proposed to reconstruct high resolution panoramic transformed images, in which consecutive images obtained by rotating motion of Omni-Vision are fused using the pocs (project on convex sets) algorithm. Experiment results are also provided to demonstrate the efficiency of the proposed method.

关键词： Catadioptric omnidirection sensor Super-Resolution Panoramic image pocs algorithm

来源：评论

学校读者我要写书评

暂无评论

Millimetre-wave radiometric imaging for concealed contraband detection on personnel

引用

IET IMAGE PROCESSING 2011年第5期5卷 375-381页

作者： Xiao, Z. Hu, T. Xu, J. Wu, L. Nanjing Univ Sci & Technol Sch Elect Engn & Optoelect Technol Nanjing Peoples R China

Millimetre-wave (MMW) radiometric imaging has established itself in a wide range of military and civil applications, but the fact that the radiometric temperature contrast between different objects indoors is low restricts the commercial application of MMW radiometric imaging to some extent. Based on the particular analysis of MMW radiometric imaging model suitable for concealed contraband detection on personnel, the method of adopting MMW noise source to illuminate the scene of being imaged to improve the radiometric temperature contrast, just like the flash lamp of camera, is proposed in this study. In addition, the choice of both the ways of illumination and the excess noise ratio (ENR) of the noise source is analysed. Then the image degradation model is discussed and the projection onto the convex sets (pocs) algorithm for MMW radiometric image super-resolution restoration is depicted in detail. In addition, a series of experiments are carried out both indoors and outdoors, with the dual-channel radiometric imaging system that has been implemented at W-band with the mode of two-dimensional planar scanning. The experimental results are presented and analysed to validate the significance of the imaging model and it is indicated that the radiometric imaging system is capable of detecting metal objects hidden underneath clothing, and the method of adopting noise illumination can improve the quality of radiometric images.

关键词： image resolution image degradation model concealed contraband detection projection onto the convex sets algorithm millimetre-wave radiometric imaging radiometry excess noise ratio image restoration Microwave measurement techniques radiometric temperature contrast two-dimensional planar scanning Thermal variables measurement object detection dual-channel radiometric imaging system Optical variables measurement MMW noise source Algebra, set theory, and graph theory millimetre wave imaging Photometry and radiometry personnel set theory Sensing devices and transducers W-band Combinatorial mathematics MMW radiometric image super-resolution restoration pocs algorithm

来源：评论

学校读者我要写书评

暂无评论

Interior reconstruction method based on rotation-translation scanning model

引用

JOURNAL OF X-RAY SCIENCE AND TECHNOLOGY 2014年第1期22卷 37-45页

作者： Wang, Xianchao Tang, Ziyue Yan, Bin Li, Lei Bao, Shanglian Air Force Early Warning Acad Wuhan Hubei Peoples R China Natl Digital Switching Syst Engn & Technol Res Ct Zhengzhou 450002 Henan Peoples R China Peking Univ Beijing City Key Lab Med Phys & Engn Beijing 100871 Peoples R China

In various applications of computed tomography (CT), it is common that the reconstructed object is over the field of view (FOV) or we may intend to sue a FOV which only covers the region of interest (ROI) for the sake of reducing radiation dose. These kinds of imaging situations often lead to interior reconstruction problems which are difficult cases in the reconstruction field of CT, due to the truncated projection data at every view angle. In this paper, an interior reconstruction method is developed based on a rotation-translation (RT) scanning model. The method is implemented by first scanning the reconstructed region, and then scanning a small region outside the support of the reconstructed object after translating the rotation centre. The differentiated backprojection (DBP) images of the reconstruction region and the small region outside the object can be respectively obtained from the two-time scanning data without data rebinning process. At last, the projection onto convex sets (pocs) algorithm is applied to reconstruct the interior region. Numerical simulations are conducted to validate the proposed reconstruction method.

关键词： CT interior reconstruction truncation pocs algorithm

来源：评论

学校读者我要写书评

暂无评论

Estimation algorithm for Large MIMO System 3rd

Estimation Algorithm for Large MIMO System

引用

3rd EAI International Conference on Future Access Enablers of Ubiquitous and Intelligent Infrastructures (Fabulous)

作者： Voicu, Carmen Berceanu, Madalina Halunga, Simona V. Univ Politehn Bucuresti Elect Telecommun & Informat Technol Fac Telecommun Dept Bucharest Romania

ISBN: (纸本)9783319922133;9783319922126

In multiuser Large MIMO communication systems, signal recovery is a relevant factor for ensuring a safe and reliable communication, especially when the users are intercorrelated. Solutions for interference minimization include analysis regarding source coding/decoding techniques, channel coding/decoding methods and multiuser detection algorithms. This paper illustrates the performance improvement brought by convex optimization technique in Large MIMO systems when the channel is affected by AWGN and Rice fading. The performance is evaluated for different sets of spreading sequences (Walsh-Hadamard and PN) and based on the simulation results several conclusions are highlighted and further improvement will be proposed for fading effects reduction and interference minimization.

关键词： Large MIMO Convex optimization pocs algorithm Multiuser MIMO Rice fading

来源：评论

学校读者我要写书评

暂无评论

Curvelet Transform Based Super-Resolution Image Processing

Curvelet Transform Based Super-Resolution Image Processing

引用

12th IEEE International Symposium on Signal Processing and Information Technology (ISSPIT)

作者： Thuong Le-Tien Luc Nguyen-Tan Giang Le-Thach Cao Bui-Thu Hochiminh City Univ Technol Dept Elect & Elect Engn 268 Ly Thuong KietDist 10 Ho Chi Minh City Vietnam Ind Univ Dept Elect Technol Ho Chi Minh City Vietnam

ISBN: (纸本)9781467356046

Super-Resolution (SR) Processing is a technique that produces a High - Resolution (HR) image from a range of Low - Resolution (LR) images. There are many methods for implementing the SR signal processing. In this paper, we introduce a specific transformation that were developed in the recent years called Curvelet Transform (CT), and then apply it in SR Processing to obtain a quality improvement of SR images. We discuss two separate algorithms using the Discrete Curvelet Transform (DCT) and then compare them based on the results of HR images. We find out that the first algorithm, named the iterative algorithm can produce better HR images than the second one, the Interpolation algorithm. However, the iterative algorithm also take more computational cost than that of the Interpolation algorithm. It is a reasonable trade-off between images quality and processing speed. We also made a comparison between our algorithms and previous works such as the Projection onto Convex Sets (pocs) and the Nearest Neighbourhood algorithms to show the quality improvement.

关键词： Curvelet Transform Superresolution Image Processing Iterative algorithm Interpolation algorithm pocs algorithm Nearest Neighbourhood algorithm

来源：评论

学校读者我要写书评

暂无评论

Registration Based Super-Resolution Reconstruction for Lung 4D-CT 36

Registration Based Super-Resolution Reconstruction for Lung ...

引用

36th Annual International Conference of the IEEE-Engineering-in-Medicine-and-Biology-Society (EMBC)

作者： Wu, Xiuxiu Xiao, Shan Zhang, Yu Southern Med Univ Sch Biomed Engn Guangzhou 510515 Guangdong Peoples R China

ISBN: (纸本)9781424479290

Lung 4D-CT plays an important role in lung cancer radiotherapy for tumor localization and treatment planning. In lung 4D-CT data, the resolution in the slice direction is often much lower than the in-plane resolution. For multi-plane display, isotropic resolution is necessary, but the commonly used interpolation operation will blur the images. In this paper, we present a registration based method for super resolution enhancement of the 4D-CT multi-plane images. Our working premise is that the low-resolution images of different phases at the corresponding position can be regarded as input. frames. to reconstruct high resolution images. First, we employ the Demons registration algorithm to estimate the motion field between different. frames.. Then, the projections onto convex sets (pocs) approach is employed to reconstruction high-resolution lung images. We show that our method can get clearer lung images and enhance image structure, compared with the cubic spline interpolation and back projection method.

关键词： lung 4D-CT super-resolution reconstruction Demons registration pocs algorithm

来源：评论

学校读者我要写书评

暂无评论

SUPER-RESOLUTION RECONSTRUCTION OF MULTI-POLARIZATION SAR IMAGES BASED ON PROJECTIONS ONTO CONVEX SETS algorithm 38

SUPER-RESOLUTION RECONSTRUCTION OF MULTI-POLARIZATION SAR IM...

引用

38th IEEE International Geoscience and Remote Sensing Symposium (IGARSS)

作者： Huang, Jin Gao, Bo Chen, Yan Chen, Yunping Tong, Ling Univ Elect Sci & Technol China Sch Automat Engn Chengdu 611731 Sichuan Peoples R China

ISBN: (纸本)9781538671504

Resolution is one of the important indices to measure the quality of SAR images. Super-resolution reconstruction is a widely adopted resolution enhancement method. Many algorithms have been developed for the super-resolution reconstruction. Among these algorithms, this paper applies projections onto convex sets algorithm to SAR image reconstruction processing. The pocs can efficiently obtain high-resolution SAR images with enhanced details. However, the pocs requires many low-resolution SAR images of the same area to gain a better result, usually 10 to 20 images. Such requirement is very difficult to achieve when only single-polarization mode is included. In this paper, we propose a novel method that utilizes all the polarimetric images of the same original SAR data for the algorithm. Thus, the number of the available images is increased exponentially. The experiment results have demonstrated the effectiveness of our proposed method: The reconstructed high-resolution SAR image based on multipolarimetric information is more detailed and clearer than that based on single-polarization information.

关键词： SAR image super-resolution reconstruction pocs algorithm multi-polarization information

来源：评论

学校读者我要写书评

暂无评论

MISSING INTENSITY RESTORATION VIA PERCEPTUALLY OPTIMIZED SUBSPACE PROJECTION BASED ON ENTROPY COMPONENT ANALYSIS

MISSING INTENSITY RESTORATION VIA PERCEPTUALLY OPTIMIZED SUB...

引用

IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)

作者： Ogawa, Takahiro Haseyama, Miki Hokkaido Univ Grad Sch Informat Sci & Technol Kita Ku Sapporo Hokkaido 0600814 Japan

ISBN: (纸本)9781479928934

A missing intensity restoration method via perceptually optimized subspace projection based on entropy component analysis (ECA) is presented in this paper. The proposed method calculates the optimal subspace of known patches within a target image based on structural similarity (SSIM) index, and the optimal bases are determined based on ECA. Then missing intensity estimation whose results maximize the SSIM index is realized by using a projection onto convex sets (pocs) algorithm whose constraints are the obtained subspace and known intensities within the target image. In this approach, a non-convex maximization problem for calculating the projection onto the subspace is reformulated as a quasi-convex problem, and the restoration of the missing intensities becomes feasible. Experimental results show that our restoration method outperforms previously reported methods.

关键词： Missing intensity restoration image quality assessment entropy component analysis pocs algorithm

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：