检索结果-内蒙古大学图书馆

Electrocardiogram sampling frequency for the optimal performance of complexity analysis and machine learning models: Discrimination between patients with and without paroxysmal atrial fi brillation using sinus rhythm electrocardiograms

引用

HEART RHYTHM O2 2025年第1期6卷 48-57页

作者： Creasy, Steven Alexeenko, Vadim Lip, Gregory Y. H. Tse, Gary Aston, Philip J. Jeevaratnam, Kamalan Univ Surrey Sch Vet Med Dept Comparat Biomed Sci Daphne Jackson Rd Guildford GU27AL Surrey England Univ Surrey Dept Math Guildford England Univ Liverpool Liverpool John Moores Univ Liverpool Ctr Cardiovasc Sci Liverpool England Liverpool Heart & Chest Hosp Liverpool England Aalborg Univ Danish Ctr Hlth Serv Res Dept Clin Med Aalborg Denmark PowerHlth Ltd Cardiovasc Analyt Grp Hong Kong Peoples R China Tianjin Med Univ Tianjin Inst Cardiol Dept Cardiol Tianjin Key Lab Ion Mol Funct Cardiovasc DisHosp Tianjin Peoples R China Hong Kong Metropolitan Univ Sch Nursing & Hlth Studies Hong Kong Peoples R China

BACKGROUND The current clinical practice to diagnose atrial fi brillation (AF) requires repeated episodic monitoring and signifi- cantly underperform in their ability to detect AF episodes. OBJECTIVE There is therefore potential for artificial intelligence- based methods to assist in the detection of AF. Better understanding of the optimal parameters for this detection can potentially improve the sensitivity for detecting AF. METHODS Ten-second, 12-lead electrocardiogram signals were analyzed using complexity algorithms combined with machine learning techniques to predict patients who had a previously detected AF episode but had since returned to normal sinus rhythm. An investigation was performed into the impact of the sampling frequency of the electrocardiogram signal on the accuracy of the machine learning models *** Using a single complexity algorithm showed a peak accuracy of 0.69 when using signals sampled at 125 Hz. In particular, it was noted that improved accuracy occurred when using lead V6 compared with other available leads. CONCLUSION Based on these results, there is potential for 12-lead electrocardiogram signals to be recorded at 125 Hz as standard and used in conjunction with complexity analysis to aid in the detection of patients with AF.

关键词： Atrial fi brillation complexity analysis Machine learning Prediction Electrocardiogram

来源：评论

学校读者我要写书评

暂无评论

complexity analysis and Synchronization Control of Fractional-Order Jafari-Sprott Chaotic System

引用

IEEE ACCESS 2020年 8卷 53360-53373页

作者： Li, Guohui Zhang, Xiangyu Yang, Hong Xian Univ Posts & Telecommun Sch Elect Engn Xian 710121 Peoples R China

Aiming at the complexity problem of fractional-order Jafari-Sprott chaotic system, in this paper, Adomian decomposition method is used to study its numerical analysis and a complexity analysis method of fractional-order Jafari-Sprott chaotic system based on fuzzy entropy algorithm, sample entropy algorithm and dispersion entropy algorithm is proposed. For the synchronization and control of fractional-order Jafari-Sprott chaotic system, sliding mode control is used to achieve synchronization of fractional-order Jafari-Sprott chaotic system and a control method of fractional-order Jafari-Sprott chaotic system is proposed based on frequency distribution model of fractional-order integral operator. The main results are as follows: (1) The complexity of the fractional-order Jafari-Sprott chaotic system is greater than the integer-order Jafari-Sprott chaotic system, and fractional-order chaotic system has better application prospects. (2) Moreover, it is concluded that the effect of the dispersion entropy algorithm on detecting complexity is the best, which provides theoretical and experimental basis for the practical engineering application of the fractional-order Jafari-Sprott chaotic system. (3) Synchronization and control of fractional-order Jafari-Sprott chaotic system is accomplished by sliding model control and frequency distribution model of fractional-order integral operator respectively. In particular, the control effect of each variable is accomplished by designing a control law based on the frequency distribution model of fractional integral operator.

关键词： Fractional-order chaotic system Adomian decomposition method complexity analysis sliding mode control frequency distribution model of fractional-order integral operator

来源：评论

学校读者我要写书评

暂无评论

complexity analysis for maximum flow problems with arc reversals

引用

JOURNAL OF COMBINATORIAL OPTIMIZATION 2010年第2期19卷 200-216页

作者： Rebennack, Steffen Arulselvan, Ashwin Elefteriadou, Lily Pardalos, Panos M. Univ Florida Dept Ind & Syst Engn Ctr Appl Optimizat Gainesville FL 32611 USA Univ Florida Dept Civil & Coastal Engn Transportat Res Ctr Gainesville FL 32611 USA

We provide a comprehensive study on network flow problems with arc reversal capabilities. The problem is to identify the arcs to be reversed in order to achieve a maximum flow from source(s) to sink(s). The problem finds its applications in emergency transportation management, where the lanes of a road network could be reversed to enable flow in the opposite direction. We study several network flow problems with the arc reversal capability and discuss their complexity. More specifically, we discuss the polynomial time algorithms for the maximum dynamic flow problem with arc reversal capability having a single source and a single sink, and for the maximum (static) flow problem. The presented algorithms are based on graph transformations and reductions to polynomially solvable flow problems. In addition, we show that the quickest transshipment problem with arc reversal capability and the problem of minimizing the total cost resulting from arc switching costs are NP-hard.

关键词： Contraflow problem Dynamic contraflow problem complexity analysis

来源：评论

学校读者我要写书评

暂无评论

complexity analysis of Three-Dimensional Fractional-Order Chaotic System Based on Entropy Theory

引用

IEEE ACCESS 2021年 9卷 73012-73028页

作者： Li, Guohui Zhang, Xiangyu Yang, Hong Xian Univ Posts & Telecommun Sch Elect Engn Xian 710121 Peoples R China

complexity analysis of fractional-order chaotic system is an interesting topic in recent years. How to measure the complexity of fractional-order chaotic system correctly and effectively is the basis of its theoretical analysis and engineering application. In this paper, complexity analysis of three-dimensional fractional-order chaotic system based on multivariate multiscale fuzzy entropy (mvMFE), multivariate multiscale sample entropy (mvMSE) and multivariate multiscale dispersion entropy (mvMDE) respectively is proposed. In the case of single parameter change, different entropy such as mvMFE, mvMSE and mvMDE are used to analyze how complexity varies with parameter. In the case of two parameters change, the change of complexity is analyzed by the chromatomap which takes two parameters as independent variable, and mvMFE, mvMSE, and mvMDE as the dependent variable when the two parameters change simultaneously. Aiming at the performance problem when the complexity of three-dimensional fractional-order chaotic system is analyzed by mvMFE, mvMSE, and mvMDE, the maximum complexity under single parameter and the detection area under two parameters are used as indicators. The result shows that the performance of mvMDE is the best, and the nonlinear term in the mathematical model of fractional-order chaotic system is positively correlated with the complexity of the system. This will provide a new method for measuring the complexity of fractional-order chaotic system, and lay the basis of theoretical analysis and practical application of fractional chaotic system in the fields of image encryption, sound encryption, image compression-encryption technique, and secure communication.

关键词： complexity theory Entropy Chaotic communication Mathematical model Heuristic algorithms Encryption Licenses Fractional-order chaotic system complexity analysis multivariate multiscale fuzzy entropy multivariate multiscale sample entropy multivariate multiscale dispersion entropy

来源：评论

学校读者我要写书评

暂无评论

complexity analysis of interior point algorithms for non-Lipschitz and nonconvex minimization

引用

MATHEMATICAL PROGRAMMING 2015年第1-2期149卷 301-327页

作者： Bian, Wei Chen, Xiaojun Ye, Yinyu Harbin Inst Technol Dept Math Harbin 150006 Peoples R China Hong Kong Polytech Univ Dept Appl Math Hong Kong Hong Kong Peoples R China Stanford Univ Dept Management Sci & Engn Stanford CA 94305 USA

We propose a first order interior point algorithm for a class of non-Lipschitz and nonconvex minimization problems with box constraints, which arise from applications in variable selection and regularized optimization. The objective functions of these problems are continuously differentiable typically at interior points of the feasible set. Our first order algorithm is easy to implement and the objective function value is reduced monotonically along the iteration points. We show that the worst-case iteration complexity for finding an scaled first order stationary point is . Furthermore, we develop a second order interior point algorithm using the Hessian matrix, and solve a quadratic program with a ball constraint at each iteration. Although the second order interior point algorithm costs more computational time than that of the first order algorithm in each iteration, its worst-case iteration complexity for finding an scaled second order stationary point is reduced to . Note that an scaled second order stationary point must also be an scaled first order stationary point.

关键词： Constrained non-Lipschitz optimization complexity analysis Interior point method First order algorithm Second order algorithm

来源：评论

学校读者我要写书评

暂无评论

complexity analysis of the iteratively regularized Gauss-Newton method with inner CG-iteration

引用

JOURNAL OF INVERSE AND ILL-POSED PROBLEMS 2009年第9期17卷 871-890页

作者： Langer, S. German Aerospace Center Member of the Helmholtz Association Institute of Aerodynamics and Flow Technology Lilienthalplatz 7 38108 Braunschweig Germany

In this paper we investigate the numerical complexity to solve nonlinear ill-posed problems when the operator equations F(x) = y(delta) are solved by the iteratively regularized Gauss Newton method (IRGNM) with inner CG-iteration. Additionally we consider a preconditioned version of the IRGNM and compare the complexity of the standard IRGNM and its preconditioned version. In the case of exponentially ill-posed problems we show the superiority of the preconditioned IRGNM, that is we prove that the preconditioning techniques presented in this paper yield a significant reduction of the total complexity.

关键词： Nonlinear inverse problems regularized Newton methods CG-method complexity analysis

来源：评论

学校读者我要写书评

暂无评论

complexity analysis based on generalized deviation for financial markets

引用

PHYSICA A-STATISTICAL MECHANICS AND ITS APPLICATIONS 2018年 494卷 118-128页

作者： Li, Chao Shang, Pengjian Beijing Jiaotong Univ Dept Math Beijing 100044 Peoples R China

In this paper, a new modified method is proposed as a measure to investigate the correlation between past price and future volatility for financial time series, known as the complexity analysis based on generalized deviation. In comparison with the former retarded volatility model, the new approach is both simple and computationally efficient. The method based on the generalized deviation function presents us an exhaustive way showing the quantization of the financial market rules. Robustness of this method is verified by numerical experiments with both artificial and financial time series. Results show that the generalized deviation complexity analysis method not only identifies the volatility of financial time series, but provides a comprehensive way distinguishing the different characteristics between stock indices and individual stocks. Exponential functions can be used to successfully fit the volatility curves and quantify the changes of complexity for stock market data. Then we study the influence for negative domain of deviation coefficient and differences during the volatile periods and calm periods. after the data analysis of the experimental model, we found that the generalized deviation model has definite advantages in exploring the relationship between the historical returns and future volatility. (C) 2017 Elsevier B.V. All rights reserved.

关键词： complexity analysis Generalized deviation Volatility Past price Financial time series

来源：评论

学校读者我要写书评

暂无评论

complexity analysis of distributed measuring and sensing network in multistage machining processes

引用

JOURNAL OF INTELLIGENT MANUFACTURING 2013年第1期24卷 55-69页

作者： Zhang, Fuqiang Jiang, Pingyu Xi An Jiao Tong Univ State Key Lab Mfg Syst Engn Xian 710049 Shaanxi Peoples R China

To obtain various underlying data from machining processes, measuring and sensing devices are required to be distributed at different machining process nodes. Considering the characteristics of multistage machining processes (MMPs), a measuring and sensing network (MSN) for analyzing product-quality and equipment-fault is proposed and its complexity is discussed. In order to establish this MSN, first, product machining form features, machining components, measuring and sensing elements are abstracted as different network nodes. The coupling relationships (such as evolving, locating, machining, inspecting and monitoring) between different nodes are mapped into network edges. Next, a level-by-level evolution model is presented to illustrate the formation procedure of establishing MSN. Then, combined with complex network theory, the related topological and physical properties are defined to analyze the MSN. Finally, a case study is put forward to demonstrate the feasibility of the proposed method.

关键词： Multistage machining processes Measuring and sensing network complexity analysis Complex network theory Formation procedure

来源：评论

学校读者我要写书评

暂无评论

complexity analysis OF WAVELET SIGNAL DECOMPOSITION AND RECONSTRUCTION

引用

IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 1994年第3期30卷 910-918页

作者： KOC, CK CHEN, GR CHUI, CK UNIV HOUSTON DEPT ELECT ENGNHOUSTONTX 77204 TEXAS A&M UNIV DEPT ELECT ENGNCOLLEGE STNTX 77843 TEXAS A&M UNIV DEPT MATHCOLLEGE STNTX 77843

We give certain sequential and parallel algorithms and their computational analysis for signal decomposition and reconstruction based on wavelets. The signal decomposition (respectively, reconstruction) process is separated into two stages: The first is the preprocessing stage where certain constants are computed for implementation to prepare for the second stage in which signal decomposition (respectively, reconstruction) is performed. In the decomposition (respectively, reconstruction) stage, the input signal is transformed via different methods to compute the output signal without changing the setup initialized in the preprocessing stage. We describe certain sequential algorithms for both the preprocessing and the decomposition (respectively, reconstruction) stages, and parallel algorithms for the latter. The algorithms are finally illustrated for compactly supported spline-wavelets and are analyzed in detail in terms of the required arithmetic operations.

关键词： Parallel algorithms wavelets computational analysis outgoing signal signal resolution Pretreatment complexity analysis input signal

来源：评论

学校读者我要写书评

暂无评论

complexity analysis of FDE receivers for massive MIMO block transmission systems

引用

IET COMMUNICATIONS 2019年第12期13卷 1762-1768页

作者： Pereira, Andreia Bento, Pedro Gomes, Marco Dinis, Rui Silva, Vitor Inst Telecomunicacoes Lisbon Portugal Univ Coimbra Dept Elect & Comp Engn P-3030290 Coimbra Portugal UNL FCT P-2829516 Caparica Portugal

This study considers massive multiple-input multiple-output (m-MIMO) schemes employing orthogonal frequency division multiplexing (OFDM) or single-carrier with frequency-domain equalisation (SC-FDE) modulation, concerning an uplink transmission. The authors study the performance and complexity for both conventional zero forcing (ZF) and minimum mean squared error (MMSE) (which require the inversion of channel matrix) and iterative frequency domain equalisation receivers based on equal gain combining (EGC) and maximum ratio combining (MRC) concepts, that do not require matrix inversions. It is shown that, although matrix inversions are generally the more complex operations for relatively balanced systems (i.e. with similar number of transmit and receive antennas), this is not generally true for systems where the channel matrix is 'very tall' (i.e. much more receive than transmit antennas), at least in terms of the number of multiplications and sums. This means that the advantage on a reduced complexity of MRC/EGC-based equalisers with respect to ZF/MMSE is, in fact, limited. However, the performance advantages combined with the possibility of parallel receiver implementations, make those techniques particularly interesting for m-MIMO schemes, either employing OFDM or SC-FDE modulations.

关键词： equalisers least mean squares methods channel estimation antenna arrays diversity reception OFDM modulation radio receivers receiving antennas MIMO communication frequency-domain analysis transmitting antennas massive MIMO block transmission systems orthogonal frequency division single-carrier frequency-domain equalisation modulation uplink transmission minimum mean squared error channel matrix equal gain matrix inversions complex operations relatively balanced systems transmit antennas multiplications sums MRC EGC-based equalisers ZF MMSE parallel receiver implementations m-MIMO schemes SC-FDE modulations complexity analysis FDE receivers maximum ratio combining concepts MRC concepts OFDM ZF error massive multiple-input multiple-output schemes SC

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：