检索结果-内蒙古大学图书馆

Trustworthy web services discovery via supervised services representation and collab.rative QoS prediction

Journal of Computational Information Systems 2012年第21期8卷 8835-8846页

作者： Chen, Lei Yang, Geng Zhang, Yingzhou Wang, Tao Mou, Bolin College of Computer Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing 210003 China

With the exponential growth of web services, the researches on how to accurately find the trustworthy services become increasingly important. Currently, some researchers have utilized the idea of services classification to minimize the services discovery duration, but seldom employed category lab.l information to further improve services representation. In addition, the existing researches always assume that the nonfunctional QoS characteristics are known, which is actually impossible in reality. In this paper, in order to address these problems, we present a trustworthy web services discovery framework named *** with the existing approaches, the TWSDisC has the two advantages. First, by using the prior category lab.l information, the TWSDisC imports the supervised Inverse Category Frequency term weighting scheme to facilitate services representation. Second, the TWSDisC adopts the state-of-the-art matrix completion technique to predict the missing QoS values and correct the corrupted ones. Experimental results performed on the real-world web services collection demonstrate the feasibility of the proposed approaches. © 2012 Binary Information Press.

关键词： Websites

来源：评论

学校读者我要写书评

暂无评论

Spectrum sensing for cognitive OFDM system using free probability theory

引用

Journal of Information and Computational Science 2011年第10期8卷 1847-1859页

作者： Wang, Lei Zheng, Baoyu Cui, Jingwu Meng, Qingmin Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab. of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education China

Free probability theory as a main branch of random matrix theory is a valuable tool for describing the asymptotic behavior of multiple systems, especially for those with large random matrices. In this paper, by using free probability theory, a new spectrum sensing scheme for cognitive OFDM system is proposed, which shows how asymptotic free behavior of random matrices and the property of Wishart distribution can be used to assist spectrum sensing for cognitive radios in such scenario. Simulation results show that the proposed scheme has a better detection performance than the energy detection technique and the maximum-minimum eigenvalue scheme even for the case of a small sample of observations. © 2011 by Binary Information Press.

关键词： Cognitive radio

来源：评论

学校读者我要写书评

暂无评论

Joint Optimization of Resource Allocation and Trajectory Based on User Trajectory for UAV-Assisted Backscatter communication System

引用

China communications 2024年第2期21卷 197-209页

作者： Peizhong Xie Junjie Jiang Ting Li Yin Lu School of Communication and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China Key Lab of Broadband Wireless Communication and Sensor Network Technology(Nanjing University of Posts and Telecommunications) Ministry of EducationNanjing 210003China

The Backscatter communication has gained widespread attention from academia and industry in recent years. In this paper, A method of resource allocation and trajectory optimization is proposed for UAV-assisted backscatter communication based on user trajectory. This paper will establish an optimization problem of jointly optimizing the UAV trajectories, UAV transmission power and BD scheduling based on the large-scale channel state signals estimated in advance of the known user trajectories, taking into account the constraints of BD data and working energy consumption, to maximize the energy efficiency of the system. The problem is a non-convex optimization problem in fractional form, and there is nonlinear coupling between optimization *** iterative algorithm is proposed based on Dinkelbach algorithm, block coordinate descent method and continuous convex optimization technology. First, the objective function is converted into a non-fractional programming problem based on Dinkelbach method,and then the block coordinate descent method is used to decompose the original complex problem into three independent sub-problems. Finally, the successive convex approximation method is used to solve the trajectory optimization sub-problem. The simulation results show that the proposed scheme and algorithm have obvious energy efficiency gains compared with the comparison scheme.

关键词： energy efficiency joint optimization UAV-assisted backscatter communication user trajectory

来源：评论

学校读者我要写书评

暂无评论

Arbitrary-Oriented Ship Detection Based on Rotation Region Locating networks in Large Scale Remote Sensing Images 4

Arbitrary-Oriented Ship Detection Based on Rotation Region L...

引用

4th IEEE International Conference on Image, Vision and Computing, ICIVC 2019

作者： Liu, Xipeng Chen, Jianxin Kang, Bin Zhang, Xuguang Nanjing University of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing China

ISBN: (纸本)9781728123257

Although deep learning has dominated the ship detection domain, it still has two challenges: arbitrary-oriented densely arranged ships cause detection omissions and large scale image contains redundant areas. This paper proposes an effective convolutional neural network framework for arbitrary-oriented ship detection in large scale and complex scenes. In this framework, we propose Cumulative Feature Pyramid networks for multi-receptive-field feature fusion, which enhances high-level semantic information at all scales. Based on the outputs of Region Proposal networks, Rotation Region Locating network predicts rotation bounding box of arbitrary-oriented ships and adopts rotation intersection over union to avoid the effect of ship dense arrangement. For large scale scenes, No-Ship Area Suppression uses OTSU algorithm to generate binary mask and then filter out non-ship regions to reduce redundant computations. Additionally, we firstly build a remote sensing image dataset for ship detection, which contains 4237 images and over 21200 ships. Experimental comparisons with the state-of-the-art approaches validate the effectiveness, accuracy and robustness of the proposed method. © 2019 IEEE.

关键词： Ships

来源：评论

学校读者我要写书评

暂无评论

Rapid computation of i-vector

Rapid computation of i-vector

引用

Speaker and Language Recognition Workshop, Odyssey 2016

作者： Xu, Longting Lee, Kong Aik Li, Haizhou Yang, Zhen Broadband Wireless Communication and Sensor Network Technology Key Lab Nanjing University of Posts and Telecommunications China Singapore

I-vector has been one of the state-of-the-art techniques in speaker recognition. The main computational load of the standard i-vector extraction is to evaluate the posterior covariance matrix, which is required in estimating the i-vector. This limits the potential use of i-vector on handheld devices and for large-scale cloud-based applications. Previous fast approaches focus on simplifying the posterior covariance computation. In this paper, we propose a method for rapid computation of i-vector which bypasses the need to evaluate a full posterior covariance thereby speeds up the extraction process with minor impact on the recognition accuracy. This is achieved by the use of subspace-orthonormalizing prior and the uniform-occupancy assumption that we introduce in this paper. From the experiments conducted on the extended core task of NIST SRE'10, we obtained significant speed-up with modest degradation in performance over the standard i-vector. © Odyssey 2016: Speaker and Language Recognition Workshop. All rights reserved.

关键词： Covariance matrix

来源：评论

学校读者我要写书评

暂无评论

Improved medical image registration based on mutual information and gradient information

Improved medical image registration based on mutual informat...

引用

2013 International Conference on Human Health and Medical Engineering, HHME 2013

作者： Zhang, Dengyin Tan, Liping Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Nanjing China

ISBN: (纸本)9781845648923

Image registration based on mutual information is widely employed in medical image processing. But this method may lead to the wrong result of registration due to the excessive local maximum points and low accuracy. As the imaging parameters of the same organs are changeless, the gray values from different images are related. Thus this paper constructed the weighted factors for the different gray pairs that represent the different registration accurate levels to improve the registration accuracy and robustness. Meanwhile, this paper introduced the difference between gradient modules which can reflect intensity of gray change on the basis of traditional gradient similarity metric function to improve accuracy. Tests prove that this new method has an improved attribute in aspects of the more obvious climaxes of parameters' curves, the finding of the extreme point, higher accuracy, and stronger robustness. © 2014 WIT Press.

关键词： Image registration

来源：评论

学校读者我要写书评

暂无评论

Compressive Wideband Spectrum Sensing Based on Random Matrix Theory

引用

Journal of Donghua University(English Edition) 2015年第2期32卷 248-251页

作者：曹开田戴林燕杭燚灵张蕾顾凯冬 Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and Telecommunications College of Overseas Education Nanjing University of Posts and Telecommunications

Spectrum sensing in a wideband regime for cognitive radio network(CRN) faces considerably technical challenge due to the constraints on analog-to-digital converters(ADCs).To solve this problem,an eigenvalue-based compressive wideband spectrum sensing(ECWSS) scheme using random matrix theory(RMT) was proposed in this *** ECWSS directly utilized the compressive measurements based on compressive sampling(CS) theory to perform wideband spectrum sensing without requiring signal recovery,which could greatly reduce computational complexity and data acquisition *** the ECWSS,to alleviate the communication overhead of secondary user(SU),the sensors around SU carried out compressive sampling at the sub-Nyquist rate instead of ***,the exact probability density function of extreme eigenvalues was used to set the *** analyses and simulation results show that compared with the existing eigenvalue-based sensing schemes,the ECWSS has much lower computational complexity and cost with no significant detection performance degradation.

关键词： compressive wideband Spectrum overhead exact eigenvalue utilized instead considerably constraints

来源：评论

学校读者我要写书评

暂无评论

Pilot Assignment Based on Graph Coloring with Sum-Rate Maximization in Cell-Free Massive MIMO 7

Pilot Assignment Based on Graph Coloring with Sum-Rate Maxim...

引用

7th International Conference on Computer and communications, ICCC 2021

作者： Chen, Rongheng Wang, Hong Song, Rongfang Nanjing University of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing China

ISBN: (纸本)9781665409506

To mitigate the severe effect of pilot contamination, a novel graph coloring (NGC) based algorithm is applied to pilot assignment in cell-free massive multiple-input multiple-output (MIMO) systems. Specifically, firstly, the potential pilot contamination intensity among users is calculated by utilizing the large-scale fading between users and access points (APs). Then, the contamination threshold is set to perform the sparsification and an interference graph describing the user interference relationship is constructed. Finally, the proposed algorithm is used to implement pilot assignment in the interference graph. In addition, an iterative grid search (IGS) approach is adopted to update the threshold to ensure that the system downlink sum-rate is maximized. The numerical results reveal that the proposed NGC pilot assignment algorithm with optimized thresholds can remarkably improve the system performance compared with previous pilot assignment schemes. © 2021 IEEE.

关键词： Graph theory

来源：评论

学校读者我要写书评

暂无评论

Data aggregation scheduling algorithm based on maximum weighted independent set for WSNs

引用

Journal of Information and Computational Science 2012年第15期9卷 4451-4459页

作者： Xu, Jian Yang, Geng Yang, Zhen Zhang, Zixiong College of Computer Science and Technology Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Lab. of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education Nanjing University of Posts and Telecommunications Nanjing 210003 China

Because sensor nodes are typically resource-constrained, the key challenge in wireless sensor networks (WSNs) design is the energy-efficiency and how to deal with the trade-off between it and the QoS parameters. Data Aggregation is an attractive technique able to cut down the data traffic, thereby reduce energy consumption, and extend the network lifetime. Meanwhile, the QoS performance of data aggregation rests with the aggregation scheduling algorithm. The previously proposed schemes consist of two phases: tree construction and scheduling. However most of them suffer from the following disadvantages: they must rely on some specific aggregation trees, and cannot guarantee the weighted fairness. Based on this defect, in this paper, we proposed an improved scheduling algorithm based on the Max Weighted Independent Set (MWIS). The aggregation scheduling methods presented here produce conflict-free schedules depending on the topology and data weight. The experiments results show that our approach have better performance in any arbitrary tree while the node of network have different priority to be scheduled. © 2012 by Binary Information Press.

关键词： Scheduling algorithms

来源：评论

学校读者我要写书评

暂无评论

Optical encryption scheme based on ghost imaging with disordered speckles

引用

Chinese Physics B 2017年第5期26卷 160-164页

作者：张玉东赵生妹 Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Nanjing 210003 China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing 210003 China

An optical encryption scheme based on a ghost imaging system with disordered speckles is proposed to obtain a higher security with a small key. In the scheme, Alice produces the random speckle patterns and obtains the detection results with the help of a computational ghost imaging（CGI） system. Then Alice permutes the order of the random speckle patterns and shares the permutation sequence as a secure key to the authorized users. With the secure key, Bob could recover the object with the principle of the CGI system, whereas, the unauthorized users could not obtain any information of the object. The numerical simulations and experimental results show that the proposed scheme is feasible with a small key, simultaneously,it has a higher security. When the eavesdropping ratio（ER） is less than 40%, the eavesdropper cannot acquire any useful information. Meanwhile, the authorized users could recover completely with the secure key.

关键词： ghost encryption secure speckle recover authorized disordered users reconstructed PSNR

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：