检索结果-内蒙古大学图书馆

2012 International Conference on Power Electronics Engineering and Computer Technology(PEECT 2012)

作者： Guangcong Zhang Beibei Xu Yuhong Zhao Department of Control Science & Engineering Zhejiang University Testing and Technology Center for Industrial Products Shenzhen Entry and Exit Inspection and Quarantine Bureau

Phase compensation is widely used for designing control systems in the frequency domain. Nonetheless, conventional algorithm for phase compensator design is imprecise in respect that the crossover frequency of the compound system is unable to determine beforehand, and thus trail-and-error is inevitable for a satisfactory precision. In this paper, a new iterative algorithm for exact design of phase compensator is proposed. This algorithm is non-trail-and-error and free of Bode-plot. Further analysis demonstrates that the algorithm converges in a non-linear speed. In addition, a case of second-order system is investigated and the result shows that the proposed algorithm is of high accuracy and efficiency.

关键词： phase compensation frequency domain design method iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

Computational methods of nonlinear tensioner damping in belt drive systems

引用

PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART D-JOURNAL OF AUTOMOBILE ENGINEERING 2023年第1期237卷 3-20页

作者： Long, Shangbin Wang, Wenlong Yue, Xia Zhang, Chunliang Qin, Wu Zhou, Chao Guangzhou Univ Sch Mech & Elect Engn Waihuan West Rd Guangzhou 510006 Peoples R China East China Jiaotong Univ Sch Mech & Vehicle Engn Nanchang Peoples R China

The friction type tensioner is an energy absorbing component in belt drive system which has hysteretic torque and nonlinear damping. In this paper, a hysteretic model is used for describing the tensioner's operating torque versus the imposed angle, and considered into the dynamic analysis of a belt drive system. The modeling process for calculating the vibration responses of a belt drive system is presented, and two iterative methods are proposed for estimating the tensioner's nonlinear damping in a varying excitation frequency. One timing belt drive system is taken as a case study. The system's vibration responses, such as the oscillation angle of tensioner arm, the transmission error between pulleys and the hub load on pulley are calculated and compared with the measured values, which validate the presented methods. The influence of iterative method on the computational efficiency and iterative accuracy are both discussed. At last a modified method is presented to improve iterative efficiency. The presented technique can improve the computational efficiency with a good computational accuracy.

关键词： Engine belt drive systems nonlinear damping hysteretic tensioner iterative algorithm varying frequency

来源：评论

学校读者我要写书评

暂无评论

Energy Management and Charging Portfolio Analysis for Future Battery Powered Harbor Vessels

引用

IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS 2023年第5期59卷 6522-6531页

作者： Tummakuri, Vidyasagar Chelliah, Thanga Raj Ramesh, U. S. Indian Inst Technol Hydropower Simulat Lab Dept Water Resource Dev & Management Roorkee 247667 Uttar Pradesh India Indian Inst Technol Hydropower Simulat Lab Dept Water Resource Dev & Management Ctr Sustainable Energy Roorkee 247667 Uttar Pradesh India Indian Maritime Univ Dept Naval Architecture & Ocean Engn Visakhapatnam 530011 India

This article intends to provide key insights to the marine designers and port authorities for adapting battery-operated zero emission electric harbor vessels (ZEE-HVs) and plan the resources for charging infrastructure. The present study is a cumulatively coordinated analysis of various significant aspects concerning the adaptation of ZEE-HVs for short-endurance commercial maritime operations. The sizing of onboard battery energy systems (OBES) is discussed for different short-endurance ZEE-HVs by considering the speed-resistance characteristics of the hull and open-water characteristics of the propeller without limiting their operations for specific load profiles/operating cycles. Charging portfolio selection is critical for a marine vessel as the OBES size is several times higher than a regular electric vehicle's battery. Hence charging portfolio selection criteria are presented to select a suitable battery charging protocol for each ZEE-HV as per the OBES ratings and available idle times on a typical day. Since the port is a commercial spot, uncertainty in resource planning leads to penalties and loss of goodwill. Therefore, Monte Carlo-based iterative analytical method is adopted to forecast the ZEE-HVs' maximum possible charging power demand on a typical day. By the load forecast data, optimal sizing of the load peak shaving battery (LPSB) was performed to limit load fluctuations at the port grid. The synergy of ZEE-HVs with LPSB and bi-directional charge-discharge controller is pivotal for effectively administering the seaport shore charging facility, which is demonstrated for a typical energy management cycle.

关键词： Battery chargers charging stations DC-DC power converters energy management iterative algorithm lithium-ion batteries marine vehicles power harmonic filters

来源：评论

学校读者我要写书评

暂无评论

Adaptive-weighted high order TV algorithm for sparse-view CT reconstruction

引用

MEDICAL PHYSICS 2023年第9期50卷 5568-5584页

作者： Xi, Yarui Zhou, Pengwu Yu, Haijun Zhang, Tao Zhang, Lingli Qiao, Zhiwei Liu, Fenglin Chongqing Univ Key Lab Optoelect Technol & Syst Minist Educ Chongqing Peoples R China Chongqing Univ Engn Res Ctr Ind Computed Tomog Nondestruct Testin Minist Educ Chongqing Peoples R China Chongqing Univ Coll Mech & Vehicle Engn Chongqing Peoples R China Chongqing Univ Arts & Sci Chongqing Key Lab Complex Data Anal & Artificial I Chongqing Peoples R China Chongqing Univ Arts & Sci Chongqing Key Lab Grp & Graph Theories & Applicat Chongqing Peoples R China Shanxi Univ Sch Comp & Informat Technol Taiyuan Shanxi Peoples R China Chongqing Univ Key Lab Optoelect Technol & Syst Minist Educ Chongqing 400044 Peoples R China

BackgroundWith the development of low-dose computed tomography (CT), incomplete data reconstruction has been widely concerned. The total variation (TV) minimization algorithm can accurately reconstruct images from sparse or noisy data. PurposeHowever, the traditional TV algorithm ignores the direction of structures in images, leading to the loss of edge information and block artifacts when the object is not piecewise constant. Since the anisotropic information can facilitate preserving the edge and detail information in images, we aim to improve the TV algorithm in terms of reconstruction accuracy via this approach. MethodsIn this paper, we propose an adaptive-weighted high order total variation (awHOTV) algorithm. We construct the second order TV-norm using the second order gradient, adapt the anisotropic edge property between neighboring image pixels, adjust the local image-intensity gradient to keep edge information, and design the corresponding Chambolle-Pock (CP) solving algorithm. Implementing the proposed algorithm, comprehensive studies are conducted in the ideal projection data experiment where the Structural similarity (SSIM), Root Mean Square Error (RMSE), Contrast to noise ratio (CNR), and modulation transform function (MTF) curves are utilized to evaluate the quality of reconstructed images in statism, structure, spatial resolution, and contrast, respectively. In the noisy data experiment, we further use the noise power spectrum (NPS) curve to evaluate the reconstructed images and compare it with other three algorithms. ResultsWe use the 2D slice in the XCAT phantom, 2D slice in TCIA Challenge data and FORBILD phantom as simulation phantoms and use real bird data for real verification. The results show that, compared with the traditional TV and FBP algorithms, the awHOTV has better performance in terms of RMSE, SSIM, and Pearson correlation coefficient (PCC) under the projected data with different sparsity. In addition, the awHOTV algorithm is robust ag

关键词： adaptive-weighted high order total variation Chambolle-Pock algorithm compressed sensing iterative algorithm image reconstruction

来源：评论

学校读者我要写书评

暂无评论

Identification of Unknown Parameters of the Dynamic Model of Mass Transfer

引用

MATHEMATICAL MODELLING AND ANALYSIS 2023年第3期28卷 459-468页

作者： Zavialov, Volodymyr Lobok, Oleksii Mysiura, Taras Popova, Nataliia Chornyi, Valentyn Pohorilyi, Taras Natl Univ Food Technol Volodymyrska Str 68 UA-01033 Kiev Ukraine

An iterative algorithm for identifying unknown parameters of a mathematical model based on the Bayesian approach is proposed, which makes it possible to determine the most probable maximum informative estimates of these parameters. The example of the mathematical model of mass transfer dynamics shows the algorithm for finding the most probable and most informative estimate of the vector of unknown parameters, and also an analysis of the sequence of the corresponding steps is given. The results of computational experiments showed a significant dependence of the results of the calculations on the choice of the initial approximation point and slowing down the rate of convergence of the iterative process (and even its divergence) with an unsuccessful choice of the initial approximation. The validity of the obtained results is provided by analytical conclusions, the results of computational experiments, and statistical modeling. The results of computational experiments make it possible to assert that the proposed algorithm has a sufficiently high convergence for a given degree of accuracy and makes it possible to derive not only estimates of point values of mathematical model parameters based on a posteriori analysis, but also confidence intervals of these estimates. At the same time, it should be noted that the results of calculations depend significantly on the choice of the initial approximation point and the slowing of the convergence rate of the iterative process with an unsuccessful choice of the initial approximation. Analytical studies and results of calculations confirm the effectiveness of the proposed identification algorithm, which makes it possible, with the help of active, purposeful experiments, to build more accurate mathematical models. In accordance with the algorithm, a program was developed in the MatLab mathematics package and computational experiments were performed.

关键词： iterative algorithm mass transfer Bayesian approach mathematical modeling variance experiment

来源：评论

学校读者我要写书评

暂无评论

A modified iterative algorithm for the (Hermitian) reflexive solution of the generalized Sylvester matrix equation

引用

TRANSACTIONS OF THE INSTITUTE OF MEASUREMENT AND CONTROL 2014年第6期36卷 815-827页

作者： Beik, Fatemeh Panjeh Ali Vali E Asr Univ Rafsanjan Dept Math Rafsanjan Iran

Recently, Ramadan et al. have focused on the following matrix equation: A(1)V + A(2)(V) over bar + B1W + B-2(W) over bar = E1VF1+ E-2(V) over barF(2)+ C and propounded two gradient- based iterative algorithms for solving the above matrix equation over reflexive and Hermitian reflexive matrices, respectively. In this paper, we develop two new iterative algorithms based on a two- dimensional projection technique for solving the mentioned matrix equation over reflexive and Hermitian reflexive matrices. The performance of our proposed algorithms is collated with the gradient- based iterative algorithms. It is both theoretically and experimentally demonstrated that the approaches handled surpass the offered algorithms in the earlier referred work in solving the mentioned matrix equation over reflexive and Hermitian reflexive matrices. In addition, it is briefly discussed that a one- dimensional projection technique can accelerate the speed of convergence of the gradient- based iterative algorithm for solving general coupled Sylvester matrix equations over reflexive matrices without assuming the restriction of the existence of a unique solution.

关键词： Matrix equation iterative algorithm reflexive matrix Hermitian reflexive matrix

来源：评论

学校读者我要写书评

暂无评论

Adaptive Parameter Alternating Direction algorithm for Centrosymmetric Solutions of a Class of Generalized Coupled Sylvester-transpose Matrix Equations

引用

FRONTIERS OF MATHEMATICS 2023年第4期18卷 977-998页

作者： Yan, Tongxin Ke, Yifen Ma, Changfeng Fujian Normal Univ Coll Math & Stat Fuzhou 350117 Peoples R China Fujian Normal Univ FJKLMAA Fuzhou 350117 Peoples R China Fujian Univ Technol Sch Comp Sci & Math Fuzhou 350118 Peoples R China

We propose an adaptive parameter alternating direction algorithm to solve a class of generalized coupled Sylvester-transpose matrix equations over centrosymmetric matrices. Under appropriate constraints, we prove that the algorithm is convergent. Finally, we illustrate the feasibility and effectiveness of this method through numerical experiments.

关键词： Adaptive parameter generalized coupled Sylvester-transpose matrix equations centrosymmetric matrices iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

Impulsive Artificial Defense Against Advanced Persistent Threat

引用

IEEE TRANSACTIONS ON INFORMATION FORENSICS AND SECURITY 2023年 18卷 3506-3516页

作者： Sun, Hao Yang, Xiaofan Yang, Lu-Xing Huang, Kaifan Li, Gang Chongqing Univ Sch Big Data & Software Engn Chongqing 400044 Peoples R China Deakin Univ Sch Informat Technol Melbourne Vic 3125 Australia

Advanced persistent threat (APT) as a new type of cyber espionage poses a severe threat to modern organizations. Artificial APT defense, in which an organization engages experienced cybersecurity experts to artificially check if there exist rootkits implanted by APT actors within the organizational internet and, if so, artificially remove the discovered rootkits, is recognized as an indispensable part of APT defense. There are two different ways of artificial APT defenses: continuous artificial defense (CAD), where the defense work is conducted at all time points, and impulsive artificial defense (IAD), where the defense work is conducted at a scheduled sequence of time points. IAD is superior to CAD in terms of the overall service cost. In the context of IAD, we refer to each sequence of service costs as an IAD policy. This paper addresses the problem of developing a cost-effective IAD policy (the IAD problem). First, by introducing an impulsive state evolutionary model for the organizational intranet, the IAD problem is reduced to an optimal impulsive control model (the IAD model). Second, by deriving the optimality system for the IAD model, an iterative algorithm for solving the IAD model (the IAD algorithm) is presented. Next, the convergence and effectiveness of the IAD algorithm are validated through numerical experiments. Finally, the effect of some factors is inspected. To our knowledge, this is the first time IAD is inspected from the perspective of optimal impulsive control theory.

关键词： Advanced persistent threat impulsive artificial APT defense IAD problem state evolutionary model optimal impulsive control model optimality system iterative algorithm convergence effectiveness

来源：评论

学校读者我要写书评

暂无评论

A collocation-based spectral element method for computing nonlinear optical waveguide

引用

INTERNATIONAL JOURNAL OF COMPUTER MATHEMATICS 2023年第3期100卷 591-614页

作者： Cheng, Ronghua Zhang, Lihong Wang, Hanquan Yunnan Univ Finance & Econ Sch Stat & Math Kunming 650221 Yunnan Peoples R China Yunnan Normal Univ Sch Math Kunming 650500 Yunnan Peoples R China

Computation of nonlinear optical waveguide needs to solve nonlinear eigenvalue/ eigenfunction problem mathematically. However, usually the refractive index profiles in the nonlinear optical waveguide are discontinuous, which makes a solution to the nonlinear eigenvalue/eigenfunction problem not smooth enough. In this work, we mainly discuss how to use the high-order collocation-based spectral element method (SEM) to discretize such a problem and propose an iterative algorithm for computing nonlinear optical waveguide with discontinuous refractive index profiles. Starting from the linear eigenvalue/eigenfunction problem, we adopt SEM to discretize it and solve the resulting discretized system with Matlab eigen solver;for the nonlinear problem, we first change the nonlinear problem into corresponding linear problems, and then solve the linear problems by the usage of the iterative method. The proposed method has the advantage of high-order accuracy and lower-order cost. The accuracy and efficiency of the method are tested by several one-dimensional and two-dimensional linear optical waveguide structures. Numerical results for some nonlinear optical waveguides are also presented.

关键词： Optical waveguide collocation-based spectral element method iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

In-Network algorithm for Passive Sensors in Structural Health Monitoring

引用

IEEE SIGNAL PROCESSING LETTERS 2023年 30卷 952-956页

作者： Insausti, Xabier Zarraga-Rodriguez, Marta Nolasco-Ferencikova, Carolina Gutierrez-Gutierrez, Jesus Univ Navarra Tecnun San Sebastian 20018 Spain

Structural health monitoring (SHM) using wireless sensor networks (WSN) has become a popular implementation, due to low maintenance and installation costs. These networks commonly use a centralized approach and battery-powered sensors, leading to energy consumption limitations, in both the central unit and the sensors. Therefore, it is of interest to consider the use of passive sensors and distributed processing in the network. In this letter, we present a distributed algorithm for SHM using wireless passive sensor networks (WPSNs) that allows any passive sensor in the network to obtain the distance to its neighbours via backscattering, and hence to detect and signal changes in the monitored structure.

关键词： Structural health monitoring (SHM) wireless passive sensor networks (WPSNs) distributed algorithm 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：