检索结果-内蒙古大学图书馆

Penalized regression analysis with individual-specific patterns of missing covariates

COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION 2024年第7期53卷 3126-3142页

作者： Liu, Zhishuai Zhan, Zishu Lin, Cunjie Renmin Univ China Ctr Appl Stat Beijing Peoples R China Renmin Univ China Sch Stat Beijing Peoples R China

High-dimensional but incomplete data are common in many settings. With such data, regularized estimation and variable selection techniques developed for complete data fail to produce reliable results due to the missingness. To address this problem, we propose an iterative penalized least squares estimation (IPLSE) method, which customizes existing penalized regression techniques for data with high missing rates and individual-specific missing patterns. The proposed method simultaneously conducts missing value imputation, parameter estimation, and variable selection. Statistical properties are rigorously established, and a simulation demonstrates its competitive performance under various missing patterns, especially when there is missingness concerning important variables. An analysis of China's provincial economic data further supports the merits of the proposed method.

关键词： High missing rate Individual-specific missing Variable selection iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

Convergence Characteristics of Domain Decomposition Method for Full-Wave Electromagnetic Analysis

引用

IEICE TRANSACTIONS ON ELECTRONICS 2024年第11期E107C卷 465-471页

作者： Murayama, Toshio Takei, Amane Univ Tokyo Tokyo 1138564 Japan Univ Miyazaki Miyazaki 8892192 Japan

A domain decomposition method is widely utilized for analyzing large-scale electromagnetic problems. The method decomposes the target model into small independent subdomains. An electromagnetic analysis has inherently suffers from late convergence analyzed with iterative algorithms such as Krylov subspace algorithms. The DDM remedies this issue by decomposing the total system into subdomain problems and gathering the local results as an interface problem to adjust to achieve the total solution. In this paper we report the convergence properties of the domain decomposition method while modifying the size of local domain and the region shape on several mesh sizes. As experimental results show, the convergence speed depends on the number of interface problem variables and the selection of the local region shapes. In addition to that the convergence property differs according to the target frequencies. In general it is demonstrated that the convergence speed can be accelerated with large cubic subdomain shape. We propose the subdomain selection strategies based on the analysis of the condition numbers of the governing equation.

关键词： finite element method domain decomposition method iterative algorithm convergence characteristics

来源：评论

学校读者我要写书评

暂无评论

Transient Stability Evaluation and Decoupled Control for Grid-Following Converters Considering Nonideal Alternating Current Control

引用

IEEE TRANSACTIONS ON POWER ELECTRONICS 2025年第7期40卷 8990-9003页

作者： Li, Xilin Feng, Pan Zhang, Ruiqi Tian, Zhen Huang, Meng Zha, Xiaoming Xiong, Xiaoling Hu, Pan Wuhan Univ Sch Elect Engn & Automat Hubei Key Lab Power Equipment & Syst Secur Integra Wuhan 430072 Peoples R China North China Elect Power Univ Sch Elect & Elect Engn Beijing 102206 Peoples R China State Grid Hubei Elect Power Res Inst Wuhan 430048 Peoples R China

In most previous studies about transient synchronization stabilities of grid-following converters (GFLC), alternating current control (ACC) dynamics are often neglected. However, the bandwidth of the ACC cannot be selected too high in some low-switching cases, such as large wind turbines. The adverse effects of ACC must be considered to avoid over-optimistic evaluation of transient stability. There are seldom quantitative and analytic large signal analyses that take the ACC dynamics into account. To fill this gap, an iteration-based accurate transient stability evaluation method is proposed in this article. First, the model of the ACC and line dynamics are deduced. The time-domain analytic solution of current dynamics is obtained. Furthermore, the multivariate implicit function equation set concerning current-frequency-power angle's mapping relation under the critical stable condition is constructed and the transient stability boundary is solved based on the proposed iterative algorithm. The interaction mechanism between the phase-locked-loop (PLL) and ACC is accurately quantified. A simplified transient stability criterion is deduced to preliminarily estimate the adverse effects of ACC on GFLC's transient stability. In addition, a stability-enhanced decoupled PLL strategy is proposed to enable the setting of PLL bandwidth unconstrained by the interaction from ACC, which significantly improves the dynamic response of the GFLC. Simulation and experiments verify the effectiveness and superiority of the proposed stability evaluation method and decoupled PLL strategy.

关键词： Phase locked loops Transient analysis Power system stability Stability criteria Numerical stability Couplings Bandwidth Synchronization Grid following Current control Alternating current control (ACC) equal area criterion (EAC) grid-following converter (GFLC) iterative algorithm phase-locked-loop (PLL) transient synchronization stability

来源：评论

学校读者我要写书评

暂无评论

Cost-Effective Company Response Policy for Product Co-Creation in Company-Sponsored Online Community

引用

IEEE TRANSACTIONS ON SYSTEMS MAN CYBERNETICS-SYSTEMS 2024年第7期54卷 4494-4506页

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

Product co-creation based on company-sponsored online community has come to be a paradigm of developing new products collaboratively with customers. In such a product co-creation campaign, the sponsoring company needs to interact intensively with active community members about the design scheme of the product. We call the collection of the rates of the company's response to active community members at all time in the co-creation campaign as a company response policy (CRP). This article addresses the problem of finding a cost-effective CRP (the CRP problem). First, we introduce a novel community state evolutionary model and, thereby, establish an optimal control model for the CRP problem (the CRP model). Second, based on the optimality system for the CRP model, we present an iterative algorithm for solving the CRP model (the CRP algorithm). Third, through extensive numerical experiments, we conclude that the CRP algorithm converges and the resulting CRP exhibits excellent cost benefit. Consequently, we recommend the resulting CRP to companies that embrace product co-creation. Next, we discuss how to implement the resulting CRP. Finally, we investigate the effect of some factors on the cost benefit of the resulting CRP. To our knowledge, this work is the first attempt to study value co-creation through optimal control theoretic approach.

关键词： Epidemics Companies Mathematical models Optimal control Costs Technological innovation Numerical models Company response policy (CRP) company-sponsored online community convergence cost benefit iterative algorithm optimal control model optimality system product co-creation state evolutionary model

来源：评论

学校读者我要写书评

暂无评论

Convergence analysis of a primal-dual optimization-by-continuation algorithm

引用

JOURNAL OF COMPUTATIONAL AND APPLIED MATHEMATICS 2025年 457卷

作者： Loris, Ignace Rebegoldi, Simone Univ Libre Bruxellles Math Dept Blvd Triomphe B-1050 Brussels Belgium Univ Modena & Reggio Emilia Dipartimento Sci Fis Informat & Matemat Via Campi 213-B I-41125 Modena Italy

We present a numerical iterative optimization algorithm for the minimization of a cost function consisting of a linear combination of three convex terms, one of which is differentiable, a second one is prox-simple and the third one is the composition of a linear map and a proxsimple function. The algorithm's special feature lies in its ability to approximate, in a single iteration run, the minimizers of the cost function for many different values of the parameters determining the relative weight of the three terms in the cost function. A proof of convergence of the algorithm, based on an inexact variable metric approach, is also provided. As a special case, one recovers a generalization of the primal-dual algorithm of Chambolle and Pock, and also of the proximal-gradient algorithm. Finally, we show how it is related to a primal-dual iterative algorithm based on inexact proximal evaluations of the non-smooth terms of the cost function.

关键词： Primal-dual algorithm Proximal algorithm Inverse problem iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

Construction and Analysis of Structure-Preserving Numerical algorithm for Two-Dimensional Damped Nonlinear Space Fractional Schrödinger equation

引用

JOURNAL OF SCIENTIFIC COMPUTING 2024年第3期99卷 60-60页

作者： Ding, Hengfei Qu, Haidong Yi, Qian Guangxi Normal Univ Ctr Appl Math Guangxi Sch Math & Stat Guilin 541006 Peoples R China Guangxi Normal Univ Educ Dept Guangxi Zhuang Autonomous Reg Key Lab Math Model & Applicat Guilin 514006 Peoples R China Hanshan Normal Univ Dept Math Chaozhou 521041 Peoples R China Guangxi Normal Univ Sch Math & Stat Guilin 541006 Peoples R China

In this paper, we present a novel high-order structure-preserving numerical scheme for solving the damped nonlinear space fractional Schrodinger equation (DNSFSE) in two spatial dimensions. The main idea of constructing new algorithm consists of two parts. Firstly, we introduce an auxiliary exponential variable to transform the original DNSFSE into a modified one. The modified DNSFSE subjects to the conservation of mass and energy, which is crucial to develop structure-preserving numerical schemes. Secondly, we construct a high-order numerical differential formula to approximate the Riesz derivative in space, which contributes to a semi-discrete difference scheme for the modified DNSFSE. Combining the semi-discrete scheme with the variant Crank-Nicolson method in time, we can obtain the fully-discrete difference scheme for solving the modified DNSFSE. The advantage of the proposed scheme is that a fourth-order convergent accuracy can be achieved in space while maintaining the conservation of mass and energy. Subsequently, we conduct a detailed study on the boundedness, uniqueness, and convergence of solution for fully-discrete scheme. Furthermore, an improved efficient iterative algorithm is proposed for the fully-discrete scheme, which has the advantage of maintaining the same convergence order as the original difference scheme. Finally, extensive numerical results are reported to further verify the correctness of theoretical analysis and the effectiveness of the proposed numerical algorithm.

关键词： Structure-preserving algorithm Numerical differential formula The damped nonlinear space fractional Schrodinger equations iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

A learning-based uplink massive-MIMO decoder

引用

WIRELESS NETWORKS 2025年第1期31卷 669-678页

作者： Kumar, Satish Mahapatra, Rajarshi Singh, Anurag Int Inst Informat Technol Elect & Commun Engn Dept Raipur 493661 Chhattisgarh India

This work presents a deep learning based iterative network for massive-MIMO decoding. The structure of DLNet is based upon a projected gradient descent-based iterative trainable network. This DLNet is a 15-layer deep iterative network structure whose parameters are optimized using DL training for better performance on Rayleigh as well as correlated M-MIMO channels. Due to rigorous training on time-varying channels, DLNet can work for time-varying channels with single-time training. Simulation shows that the proposed DLNet decoder performs better than other MIMO decoding techniques by at least 2 dB in symbol-error-rate (SER), at least 11 times faster than the baseline (OAMPNet), and 9 times less complex. It also converges fast compared to other available M-MIMO decoders.

关键词： Massive MIMO decoding Deep learning Correlated channels Training iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

Application of the Van Cittert algorithm for Deconvolving Loss Features in X-ray Photoelectron Spectroscopy Spectra

引用

MATERIALS 2024年第3期17卷 763-763页

作者： Speranza, Giorgio Fdn Bruno Kessler v Sommar 18 I-38123 Trento Italy Univ Trento Dept Ind Engn v Sommar 9 I-38123 Trento Italy CSMFO Lab IFN CNR v Cascata 56-C I-38123 Trento Italy

The convolution of two physical entities, denoted as f and g, delineates the manner in which one entity undergoes modification in response to the other. This transformative process is mathematically represented by the expression f circle times g, symbolizing the convolution of the two entities in a resultant function h. Frequently, it becomes imperative to comprehend the magnitude of the induced modifications. From the derived function h, a crucial step involves the separation of the two original signals, a process commonly referred to as deconvolution. Various techniques have been proposed to facilitate the calculation of the deconvolution, with one notable approach originating in 1931 by van Cittert. The algorithm, based on an iterative method, has been scrutinized over time, notably by Bracewell and, more recently, by Jansson. This work represents the current state-of-the-art, focusing specifically on the analysis of Auger spectra obtained through XPS. Emphasis is placed on delineating the procedural aspects of the analysis, and the algorithm utilized in the open-source software RxpsG is comprehensively described.

关键词： deconvolution spectral interference noise interference van Cittert iterative algorithm

来源：评论

学校读者我要写书评

暂无评论

Wideband 2-D DoA Estimation With Uniform Circular Array

引用

IEEE SENSORS JOURNAL 2024年第7期24卷 11585-11598页

作者： Ding, Xiaorui Xu, Wenbo Wang, Yue Li, Yingshu Huang, Yan Beijing Univ Posts & Telecommun Key Lab Universal Wireless Commun Minist Educ Beijing 100876 Peoples R China Georgia State Univ Dept Comp Sci Atlanta GA 30303 USA Kennesaw State Univ Coll Comp & Software Engn Atlanta GA 30144 USA

Direction-of-arrival (DoA) estimation is a critical technique in radio signal-based sensing. With the advancement of integration of sensing and communication, the demand for low-latency sensing based on wideband signals is increasing, thus efficient wideband DoA estimation with high performance is desirable. In this article, an iterative coherent signal-subspace method (CSM) including three main steps in each iteration is proposed for wideband 2-D DoA estimation with a uniform circular array (UCA), the input of which is the narrowband signals at multiple frequency points divided by Fourier transform from the wideband signal. The first step selects partial frequency points for the subsequent focusing process. The second step performs the focusing process with the angle intervals that designed for generating the focusing matrices, where the received signal-subspaces at the selected frequency points are focused into a reference frequency. The DoAs are estimated by the multiple signal classification (MUSIC) algorithm with a range-shrunk spatial spectrum in the third step. The DoA estimation results of the previous iterations are utilized in the subsequent iterations to refine the estimation accuracy. Furthermore, the computational complexity of the proposed method is theoretically analyzed to demonstrate its efficiency. Besides, the Cramer-Rao bound (CRB) of the investigated scenario of DoA estimation is derived as a performance benchmark, based on which the guidelines for estimation performance improvement are provided. The simulation results indicate that the proposed method enjoys preferable estimation performance and efficiency.

关键词： Direction-of-arrival estimation Estimation Wideband Focusing Sensors Narrowband Antenna arrays Array signal processing coherent signal-subspace method (CSM) Cramer-Rao bound (CRB) iterative algorithm uniform circular array (UCA) wideband direction-of-arrival (DoA) estimation

来源：评论

学校读者我要写书评

暂无评论

Incorporating Data-Driven Demand-Price Uncertainty Correlations Into Microgrid Optimal Dispatch

引用

IEEE TRANSACTIONS ON SMART GRID 2024年第3期15卷 2804-2818页

作者： Qiu, Haifeng Liu, Pengxiang Gu, Wei Zhang, Rufeng Lu, Shuai Gooi, Hoay Beng Nanyang Technol Univ Sch Elect & Elect Engn Singapore 639798 Singapore Southeast Univ Sch Elect Engn Nanjing 210096 Peoples R China Northeast Elect Power Univ Dept Elect Engn Jilin 132012 Peoples R China

A growing number of microgrid (MG) systems ipate in market trading as prosumers to improve their own operation profits, as well as the flexibility of power supply. To handle the MG dispatch problem with uncertainties in both load demands and electricity prices, this paper provides a data-driven robust optimization (RO) approach. Firstly, the correlations between the uncertainties of demands and prices are verified via the analysis of historical monitoring data from a real-world case. Based on the data-fitting for the rectangular and ellipsoidal intervals, a new data-driven demand-price uncertainty set with correlations is built to eliminate these unreasonable scenarios effectively. Secondly, a two-stage RO dispatch model is established considering multiple uncertainties of renewable-load power and prices in MGs. The bilinear objective term brings huge obstacles to the solution of the RO model, therefore a novel nested iterative algorithm is further exploited. The bilinear terms of power and price in the objective function are linearized by a binary expansion approach. Besides, to avoid the enumerations of numerous binary recourses in problem solving, the block coordinate descent (BCD) theory is adopted to co-optimize different types of variables, thereby enhancing the computational tractability. Numerical simulations indicate the validity and superiority of the developed RO model and the solution algorithm.

关键词： Data-driven uncertainty set demand-price correlations iterative algorithm microgrid dispatch two-stage robust optimization

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：