检索结果-内蒙古大学图书馆

Time-pattern design for transmission energy allocation in wireless sensor networks

IET COMMUNICATIONS 2017年第7期11卷 1028-1035页

作者： Li, Feng Wang, Li Meng, Limin Zhang, Yu Pan, Qing Zhejiang Univ Technol Coll Informat Engn Hangzhou Zhejiang Peoples R China

Cooperative transmission is an efficient method for wireless sensor networks (WSNs) to decrease power consumption of sensor nodes and combat the fast fading inherent to wireless multipath channels. During the course, a key issue is how a sensor relay handles the balance between assisting other nodes' communication and accomplishing its own transmission tasks. To address this problem, this study investigates the potential bargaining for resource allocation in WSNs over Rayleigh fading environments by considering energy fairness in cooperative transmission. Specifically, based on the characteristics of Rayleigh fading channel, a relevant system model is built. Then, after analysing the system capacity with a given outage probability over the fading channels, a system utility function for transmit-time allocation is proposed to address the participants' energy concern. An iterative algorithm is subsequently achieved by solving the Nash equilibrium. Furthermore, essential analysis and discussion on the pure equilibrium and convergence conditions of the iterative algorithm are provided. Finally, numerical results are presented to evaluate the feasibility and system performance of the proposed framework.

关键词： wireless sensor networks cooperative communication Rayleigh channels multipath channels relay networks (telecommunication) resource allocation probability channel capacity iterative methods game theory time-pattern design transmission energy allocation wireless sensor network cooperative transmission WSN power consumption wireless multipath channel fast fading inherent channel resource allocation Rayleigh fading channel relevant system model outage probability transmit-time allocation iterative algorithm Nash equilibrium

来源：评论

学校读者我要写书评

暂无评论

Controller synthesis for positive Takagi-Sugeno fuzzy systems under l₁ performance

引用

INTERNATIONAL JOURNAL OF SYSTEMS SCIENCE 2017年第3期48卷 515-524页

作者： Chen, Xiaoming Lam, James Meng, Min Nanjing Univ Aeronaut & Astronaut Coll Automat Engn Nanjing Jiangsu Peoples R China Univ Hong Kong Dept Mech Engn Pokfulam Rd Hong Kong Hong Kong Peoples R China Shandong Univ Sch Math Jinan Peoples R China

In this paper, the problem of l(1)-induced controller design for positive Takagi-Sugeno (T-S) fuzzy systems is investigated with the use of linear Lyapunov function. A novel performance characterisation is first established to guarantee the asymptotic stability of the closed-loop system with l(1)-induced performance. Moreover, sufficient conditions are presented to design the required fuzzy controllers and iterative convex optimisation approaches are developed to solve the conditions. Finally, two examples are presented to show the effectiveness of the derived theoretical results.

关键词： iterative algorithm linear Lyapunov functions l(1)-induced performance positive T-S fuzzy systems

来源：评论

学校读者我要写书评

暂无评论

Obtention of the constitutive equation of hydride blisters in fuel cladding from nanoindentation tests

引用

JOURNAL OF NUCLEAR MATERIALS 2017年 487卷 220-228页

作者： Rengel, M. A. Martin Gomez, F. J. Rico, A. Ruiz-Hervias, J. Rodriguez, J. Univ Politecn Madrid ETSI Caminos Canales & Puertos C Prof Aranguren 3 E-28040 Madrid Spain AMS Bilbao Spain Univ Rey Juan Carlos DIMME Mostoles Spain

It is well known that the presence of hydrides in nuclear fuel cladding may reduce its mechanical and fracture properties. This situation may be worsened as a consequence of the formation of hydride blisters. These blisters are zones with an extremely high hydrogen concentration and they are usually associated to the oxide spalling which may occur at the outer surface of the cladding. In this work, a method which allows us to reproduce, in a reliable way, hydride blisters in the laboratory has been devised. Depth-sensing indentation tests with a spherical indenter were conducted on a hydride blister produced in the laboratory with the aim of measuring its mechanical behaviour. The plastic stress-strain curve of the hydride blister was calculated for first time by combining depth-sensing indentation tests results with an iterative algorithm using finite element simulations. The algorithm employed reduces, in each iteration, the differences between the numerical and the experimental results by modifying the stress-strain curve. In this way, an almost perfect adjustment of the experimental data was achieved after several iterations. The calculation of the constitutive equation of the blister from nanoindentation tests, may involve a lack of uniqueness. To evaluate it, a method based on the optimization of parameters of analytical equations has been proposed in this paper. An estimation of the error which involves this method is also provided. (C) 2017 Elsevier B.V. All rights reserved.

关键词： Nuclear fuel cladding Hydride blister Nanoindentation iterative algorithm Constitutive equation Uniqueness

来源：评论

学校读者我要写书评

暂无评论

Robust maximum signal fraction analysis for blind source separation

引用

IET SIGNAL PROCESSING 2017年第8期11卷 969-974页

作者： Lu, Xuesong Li, Xiaomeng Fu, Mao-sheng Wang, Haixian Southeast Univ Zhongda Hosp Dept Rehabil Nanjing 210009 Jiangsu Peoples R China Southeast Univ Res Ctr Learning Sci Nanjing 210096 Jiangsu Peoples R China West Anhui Univ Sch Elect & Informat Engn Luan 237012 Anhui Peoples R China Foshan Univ Sch Math & Big Data Foshan 528000 Guangdong Peoples R China

Blind source separation (BSS) is an active research topic in the fields of biomedical signal processing and brain-computer interface. As a representative technique, maximum signal fraction analysis (MSFA) has been recently developed for the problem of BSS. However, MSFA is formulated based on the L2-norm, and thus is prone to be negatively affected by outliers. In this study, the authors propose a robust alternative to MSFA based on the L1-norm, termed as MSFA-L1. Specifically, they re-define the objective function of MSFA, in which the energy quantities of both the signal and the noise are defined with the L1-norm rather than the L2-norm. By adopting the L1-norm, MSFA-L1 alleviates the negative influence of large deviations that are usually associated with outliers. Computationally, they design an iterative algorithm to optimise the objective function of MSFA-L1. The iterative procedure is shown to converge under the framework of bound optimisation. Experimental results on both synthetic data and real biomedical data demonstrate the effectiveness of the proposed MSFA-L1 approach.

关键词： blind source separation medical signal processing brain-computer interfaces iterative methods optimisation robust maximum signal fraction analysis blind source separation BSS active research topic biomedical signal processing brain-computer interface representative technique maximum signal fraction analysis MSFA iterative algorithm iterative procedure bound optimisation real biomedical data

来源：评论

学校读者我要写书评

暂无评论

Parameter estimation algorithms for Hammerstein time-delay systems based on the orthogonal matching pursuit scheme

引用

IET SIGNAL PROCESSING 2017年第3期11卷 265-274页

作者： Mao, Yawen Ding, Feng Liu, Yanjun Jiangnan Univ Key Lab Adv Proc Control Light Ind Minist Educ Sch Internet Things Engn Wuxi 214122 Peoples R China

This study focuses on the parameter estimation of Hammerstein non-linear systems with unknown time-delay and coloured noise. By means of the compressed sensing recovery theory and the auxiliary model identification idea, an orthogonal matching pursuit based iterative algorithm is proposed for estimating the system parameters and the time delay. The proposed algorithms can give highly accurate parameter estimates from a small number of observations. Two simulation examples are provided to test the proposed algorithms.

关键词： parameter estimation iterative methods time-frequency analysis compressed sensing parameter estimation Hammerstein time-delay systems orthogonal matching pursuit scheme Hammerstein nonlinear systems unknown time-delay coloured noise compressed sensing recovery auxiliary model identification iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

Modified algorithm of Sinusoid Signal Frequency Estimation Based on Quinn and Aboutanios iterative algorithms

Modified Algorithm of Sinusoid Signal Frequency Estimation B...

引用

2016 IEEE 13th International Conference on Signal Processing（ICSP2016）

作者： Gao Yue Zhang Xiong Song Jun Nanjing Forestry University

The problem of estimating the frequency of a complex signal is considered. Through analyzing the performance of the Quinn algorithm and Aboutanios iterative algorithm, when the frequency of signal is located in the central region of two neighboring quantized frequency in discrete Fourier transform(DFT), Quinn algorithm's precision is very high and its rootmean-square error(RMSE) is close to Cramer-Rao bound(CRB).Meanwhile, the variance of frequency estimated by the Aboutanios iterative algorithm is big. However, when the frequency is located in the vicinity of quantitative frequency point, the Quinn algorithm's accuracy is poor and Aboutanios iterative algorithm has high precision. In this paper, through combining the advantages of two kinds of algorithms and obtaining the correct interpolation direction by spectral shift in the vicinity of quantitative frequency point, there is a new comprehensive algorithm which has better computational efficiency and its RMSE is close to the CRB in the entire frequency estimation range.

关键词： parameter estimation iterative algorithm sinusoid signal frequency estimation

来源：评论

学校读者我要写书评

暂无评论

Hybrid Pre-Log and Post-Log Image Reconstruction for Computed Tomography

引用

IEEE TRANSACTIONS ON MEDICAL IMAGING 2017年第12期36卷 2457-2465页

作者： Wang, Guobao Zhou, Jian Yu, Zhou Wang, Wenli Qi, Jinyi Univ Calif Davis Dept Biomed Engn Davis CA 95616 USA Univ Calif Davis Sch Med Dept Radiol Sacramento CA 95817 USA Toshiba Med Res Inst Vernon Hills IL 60061 USA Columbia Univ Dept Radiat Oncol New York NY 10027 USA

Tomographic image reconstruction for low-dose computed tomography (CT) is increasingly challenging as dose continues to reduce in clinical applications. Pre-log domain methods and post-log domain methods have been proposed individually and each method has its own disadvantage. While having the potential to improve image quality for low-dose data by using an accurate imaging model, pre-log domain methods suffer slow convergence in practice due to the nonlinear transformation from the image to measurements. In contrast, post-log domain methods have fast convergence speed but the resulting image quality is suboptimal for low-dose CT data because the log transformation is extremely unreliable for low-count measurements and undefined for negative values. This paper proposes a hybrid method that integrates the pre-log model and post-log model together to overcome the disadvantages of individual pre-log and post-log methods. We divide a set of CT data into high-count and low-count regions. The post-log weighted least squares model is used for measurements in the high-count region and the pre-log shifted Poisson model for measurements in the low-count region. The hybrid likelihood function can be optimized using an existing iterative algorithm. Computer simulations and phantom experiments show that the proposed hybrid method can achieve faster early convergence than the pre-log shifted Poisson likelihood method and better signal-to-noise performance than the post-logweighted least squares method.

关键词： Low-dose CT image reconstruction iterative algorithm noise model shifted Poisson weighted least squares

来源：评论

学校读者我要写书评

暂无评论

Energy-efficient dual-layer coordinated beamforming scheme in multi-cell massive multiple-input-multiple-output systems

引用

IET COMMUNICATIONS 2017年第1期11卷 30-38页

作者： Mei, Jie Zhao, Long Zheng, Kan Wang, Xiaoyu Beijing Univ Posts & Telecommun Wireless Signal Proc & Network Lab Minist Educ Beijing 100876 Peoples R China Orange Labs Int Ctr Beijing Orange Int Labs China NPIT Beijing 100013 Peoples R China

To improve the energy efficiency of multi-cell massive multiple-input-multiple-output system while guaranteeing the information transmission quality, this study proposes a dual-layer coordinated beamforming scheme. In the proposed scheme, the beamformer at each evolved node B (eNB) is divided into a cell-layer beamformer and a user-layer beamformer. The cell-layer beamformer is used to mitigate inter-cell interference (ICI) by exchanging long-term channel state information (CSI) among eNBs. The user-layer beamformer serves user according to the local real-time CSI at each eNB. On the basis of the dual-layer structure, the cell-layer beamformers, the user-layer beamformers, and power allocation are jointly optimised in order to minimise the total transmit power across all the eNBs subject to the signal-to-interference-plus-noise ratio requirements and single-antenna power constraints. To make the original problem solvable, the ICI is replaced by its upper bound. Then, the problem is partitioned into two convex sub-problems, and two iterative algorithms are proposed in order to find the sub-optimal solution to the original optimisation problem. Simulation results show that the proposed scheme performs better than two reference schemes including the existing zero-forcing scheme and coordinative multiple point schemes.

关键词： array signal processing MIMO communication cellular radio interference suppression radiofrequency interference energy conservation wireless channels antenna arrays convex programming energy-efficient dual-layer coordinated beamforming scheme multicell massive multiple-input–multiple-output system information transmission quality evolved node B eNB user-layer beamformer cell-layer beamformer intercell interference mitigation ICI mitigation channel state information CSI power allocation signal-to-interference-plus-noise ratio requirement single-antenna power constraint convex subproblem iterative algorithm optimisation problem zero-forcing scheme coordinative multiple point scheme

来源：评论

学校读者我要写书评

暂无评论

A parametric intensity-based 3D image registration method for magnetic resonance imaging

引用

SIGNAL IMAGE AND VIDEO PROCESSING 2017年第3期11卷 455-462页

作者： Song, Huajun Qiu, Peihua China Univ Petr East China Coll Informat & Control Engn Qingdao Peoples R China Univ Florida Dept Biostat Gainesville FL 32611 USA

Image registration (IR) aims to map one image to another of a same scene. With rapid progress in image acquisition technologies, 3D IR becomes an important problem in magnetic resonance imaging (MRI) and other applications. In the literature, however, most IR methods are for 2D images and there are only a limited number of 3D methods available. Because 3D images have much complicated structure than their 2D counterparts, 3D IR is not just a simple generalization of the 2D IR problem. In this paper, we develop a 3D IR method that can handle cases with affine geometric transformations well. By its definition, an affine transformation maps a line to a line, and it includes rotation, translation, and scaling as special cases. In practice, most geometric transformations involved in IR problems are affine transformations. Therefore, our proposed method can find many IR applications. It is shown that this method works well in various cases, including cases when the data size of a 3D image is reduced for different reasons. This latter property makes it attractive for many 3D IR applications, since 3D images are often big in data size and it is natural to reduce their size for fast computation.

关键词： Function approximation Geometric transformation Image mapping iterative algorithm Kernel estimation Performance evaluation

来源：评论

学校读者我要写书评

暂无评论

A receding frictional contact problem between a graded layer and a homogeneous substrate pressed by a rigid punch

引用

MECHANICS OF MATERIALS 2017年第Nov.期114卷 201-214页

作者： El-Borgi, Sami Comez, Isa Texas A&M Univ Qatar Mech Engn Program Engn BldgPOB 23874 Doha Qatar Karadeniz Tech Univ Dept Civil Engn TR-61080 Ortahisar Trabzon Turkey

This paper considers the plane problem of a receding frictional nonlinear contact between an elastic graded layer and a homogeneous half-space when they are pressed against each other by a rigid stamp. A non-homogenous isotropic stress-strain law was used to model the graded layer. The contact region is assumed to be under sliding contact conditions with Coulombs law relating the tangential traction to the normal component. Applying Fourier integral transform and the appropriate boundary conditions, the plane elasticity equations are converted analytically into a system of singular integral equations in which the unknowns are the pressures and receding contact lengths in the two contact zones. Ensuring mechanical equilibrium is an indispensable requirement warranted by the physics of the problem and therefore the global force and moment equilibrium conditions for the stamp and the layer are supplemented to solve the problem. The Gauss-Chebyshev quadrature-collocation method is used to convert the singular integral equations into a set of nonlinear equations which are solved with a newly developed iterative algorithm to yield the lengths of the receding contact zones and the associated contact pressures. The main focus of this paper is to investigate the effect of the non-homogeneity parameter of the graded layer, the friction coefficient in the contact zones and the radius of the stamp profile on the contact pressures and lengths of the receding contact zones. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Functionally graded material Plane receding frictional contact Cylindrical punch Singular integral equations Gauss-Chebyshev quadrature-collocation iterative 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：