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Tracking online low-rank approximations of higher-order incomplete streaming tensors

PATTERNS 2023年第6期4卷 100759页

作者： Thanh, Le Trung Abed-Meraim, Karim Trung, Nguyen Linh Hafiane, Adel Univ Orleans PRISME Lab INSA CVL 12 Rue Blois F-45100 Orleans France VNU Univ Engn & Technol AVITECH Inst 144 Xuan Thuy Hanoi 10000 Vietnam Acad Inst France 1 Rue Descartes F-75005 Paris France

In this paper, we propose two new provable algorithms for tracking online low-rank approximations of high order streaming tensors with missing data. The first algorithm, dubbed adaptive Tucker decomposition (ATD), minimizes a weighted recursive least-squares cost function to obtain the tensor factors and the core tensor in an efficient way, thanks to an alternating minimization framework and a randomized sketching technique. Under the canonical polyadic (CP) model, the second algorithm, called ACP, is developed as a variant of ATD when the core tensor is imposed to be identity. Both algorithms are low-complexity tensor trackers that have fast convergence and low memory storage requirements. A unified convergence analysis is presented for ATD and ACP to justify their performance. Experiments indicate that the two proposed algorithms are capable of streaming tensor decomposition with competitive performance with respect to estimation accuracy and runtime on both synthetic and real data.

关键词： tensor decomposition low-rank approximation adaptive algorithm streaming tensor missing data randomized method

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Adaptation of Antenna Arrays with Using Correlation Matrices of a Special Types

Adaptation of Antenna Arrays with Using Correlation Matrices...

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Conference on Systems of Signal Synchronization, Generating and Processing in Telecommunications (SYNCHROINFO)

作者： Glushankov, E., I Kirik, D., I Kirsanov, D. M. Rylov, E. A. Bonch Bruevich St Petersburg State Univ Telecommu St Petersburg Russia AO PKB RIO St Petersburg Russia

ISBN: (纸本)9781665415491

To reduce the computational complexity of direct methods for adapting linear equidistant antenna arrays, the correlation matrices of the input signals were approximated by matrices of a special type related to Toeplitz and block-Toeplitz matrices. It is shown that the sample correlation matrices used in adaptation, due to the use of samples of limited length in their estimation, do not belong to matrices of a special type and can be approximated by them with limited accuracy. The accuracy of such an estimation is estimated and the simulation of direct methods using the MATLAB environment is carried out, on the basis of which recommendations are given on the use of direct methods for adapting antenna arrays.

关键词： antenna array correlation matrix adaptive algorithm Toeplitz matrix

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A New Flame Image Edge Detection algorithm for Reconstruction of the Internal Temperature Field in the Furnace 40

A New Flame Image Edge Detection Algorithm for Reconstructio...

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40th Chinese Control Conference (CCC)

作者： Tao, Wang Peng, Chen Wei, Wang Gang, Yusen Zeng, Deliang Shanghai Univ Sch Mech & Elect Engn & Automat Shanghai 200444 Peoples R China North China Elect Power Univ Sch Control & Comp Engn Beijing 102206 Peoples R China

ISBN: (纸本)9789881563804

For a coal-fired boiler, it is always a difficult problem to reconstruct the internal temperature field. Due to the complex environment inside the furnace, the traditional reconstruction methods are not suitable for the furnace, so the current mainstream methods are based on the characteristics of the furnace internal flame image to reconstruct the temperature field. But the flame image inside the furnace is easily affected by external factors, especially the background. Therefore, it is very important to detect the edge of the flame image and extract the separate flame image for the subsequent temperature field reconstruction. For this purpose, a new edge detection method is proposed in this paper. First, a new rule is designed for color image to gray image. The rule can improve the gray difference between flame target and background area. Then the threshold segmentation algorithm is used to preprocess the flame gray image, and a new weighted edge image calculation method is designed to capture more details of the flame edge. Finally, an adaptive double threshold algorithm is used to remove the false edge in the flame edge. The simulation results show that the method is effective and can detect the continuous flame edge very well. It is of great practical value for the temperature field reconstruction in the furnace.

关键词： Flame Image Image Processing Edge Detection adaptive algorithm

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adaptive algorithms for computing the principal Takagi vector of a complex symmetric matrix

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NEUROCOMPUTING 2018年 317卷 79-87页

作者： Che, Maolin Qiao, Sanzheng Wei, Yimin Southwest Univ Finance & Econ Sch Econ Math Chengdu 611130 Sichuan Peoples R China McMaster Univ Dept Comp & Software Hamilton ON L8S 4K1 Canada Fudan Univ Sch Math Sci Shanghai 200433 Peoples R China Fudan Univ Key Lab Math Nonlinear Sci Shanghai 200433 Peoples R China

In this paper, we present a unified framework for deriving and analyzing adaptive algorithms for computing the principal Takagi vector of a complex symmetric matrix. Eight systems of complex-valued ordinary differential equations (complex-valued ODEs) are derived and their convergence behavior is analyzed. We prove that the solutions of the complex-valued ODEs are asymptotically stable. The systems can be implemented on neural networks. Finally, we show experimental results to support our analyses. (C) 2018 Elsevier B.V. All rights reserved.

关键词： Complex symmetric matrix Takagi factorization Principal Takagi vector adaptive algorithm Asymptotic stability

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A MPPT Control Method. Based on the Improved Wind-Driven Optimization 16

A MPPT Control Method. Based on the Improved Wind-Driven Opt...

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16th IEEE Conference on Industrial Electronics and Applications (ICIEA)

作者： Liu, Hongpeng Shi, Yuxin Zhang, Wei Northeast Elect Power Univ Sch Elect Engn Key Lab OfModern Power Syst Simulat & Control & R Minist Educ Jilin Jilin Peoples R China

ISBN: (纸本)9781665422482

With the development of photovoltaic power generation, there is an urgent problem to be solved about how to improve the efficiency of photovoltaic power generation systems. For the nonlinear output characteristics of photovoltaic arrays, fast and accurate tracking method of the maximum power point has become the topic of research. The traditional maximum power point tracking methods do not consider the tracking speed and accuracy at the same time, and there are often problems with oscillation and misjudgment. In order to solve the problems above, the wind-driven optimization algorithm is studied and an improved adaptive wind-driven optimization algorithm is proposed, which not only has fast tracking speed and higher tracking accuracy, but also greatly reduces the steady-state oscillation. Finally, the superiority of proposed method comparing with the wind-driven optimize algorithm has been verified with the simulation results based on MATLAB/Simulink under the sudden changes of the external environment.

关键词： photovoltaic inverter maximum power point tracking wind-driven optimization adaptive algorithm

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On the Thermal Efficiencies of Cascading Heat Exchangers: An algorithmic Approach - II 20

On the Thermal Efficiencies of Cascading Heat Exchangers: An...

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20th InterSociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm)

作者： Subrahmanyam, Prabhakar Tadayon, Pooya Polyanko, Victor Diglio, Paul Mohammed, Rahima Bianco, Mark Intel Corp Santa Clara CA 95054 USA Intel Corp Hillsboro OR USA

ISBN: (纸本)9781728185392

scalable design architecture for addressing optimal temperature performance on demand is investigated and implemented in this research using novel algorithmic methods. The thermal efficiencies of cascading multiple heat exchangers (HEX) in a parallel fashion networked to multiple cold plates is presented. An in-depth, self-learning algorithmic approach is presented to characterize power and performance perspectives. Several novel algorithmic approaches aimed at reducing transient thermal solution response time for coolant flow branching to dynamically and to preemptively address the 6dFffaffUffaeffO has been investigated and implemented in this design. The dynamic algorithm also calculates the efficiency of the system based on the heat picked up by the cold plate and heat dumped by the HEX upon recirculation and forced convectively cooled by the fans blowing on the HEX relative to the ambient temperature. The apparatus once deployed, is driven by algorithmic methods without the need for human intervention and the flow control is automated. Experimental data for quad HEX configuration dissipating 4 kW on multiple cold plates is presented. The algorithm automatically branches coolant to the cold plates only when power is being dissipated by the package under the cold plate. A plug and play, adaptive, coolant flow branching system that removes human intervention and dynamically optimizes thermal efficiency based on real-time, dynamic power changing conditions is implemented and presented in this research. When implemented in data centers, this is projected to optimize TCO (Total Cost of Ownership) at the rack level and for large scale deployment & adoption at data centers.

关键词： LAAC adaptive algorithm heat exchangers thermal efficiency cascading radiators LMTD O-NTU high heat flux performance on demand efficiency parameter

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Research on Thermal-Hydraulic Parameter Prediction Method of the Small Lead-Bismuth Fast Reactor Core Based on adaptive RBF Neural Network

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FRONTIERS IN ENERGY RESEARCH 2022年 10卷

作者： Wu, Hong Li, Ren Zhao, Pengcheng Yu, Tao Zhao, Yanan Univ South China Sch Nucl Sci & Technol Hengyang Peoples R China Harbin Engn Univ Coll Nucl Sci & Technol Harbin Peoples R China

In this study, a cladding surface temperature prediction method based on an adaptive RBF neural network was proposed. This method can significantly improve the accuracy and efficiency of the thermal safety evaluation of the lead-bismuth fast reactor. First, based on the sub-channel analysis program SUBCHANFLOW, the core sub-channel model of the small lead-bismuth fast reactor SPALLER-100 was established. Second, the calculated 2000 groups of core power distribution and coolant flow distribution data were used as training samples. The adaptive RBF neural network model was trained to predict the surface temperature of fuel elements in the lead-bismuth fast reactor. Finally, by comparison, the effectiveness and superiority of the adaptive RBF neural network method were proved. The results indicate that the relative error of the maximum temperature of the fuel cladding predicted using the adaptive RBF neural network method was less than 0.5%, which can be used for the rapid prediction of the thermal and hydraulic parameters of the lead-bismuth fast reactor.

关键词： RBF neural network adaptive algorithm small lead-bismuth fast reactor thermal safety SUBCHANFLOW

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Dynamic Geometry Control for Robust Aerodynamic Shape Optimization

Dynamic Geometry Control for Robust Aerodynamic Shape Optimi...

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AIAA Aviation Forum and Exposition

作者： Streuber, Gregg M. Zingg, David W. Univ Toronto Inst Aerosp Studies Toronto ON M3H 5T6 Canada

ISBN: (数字)9781624106101

ISBN: (纸本)9781624106101

This work presents novel progressive and adaptive dynamic geometry control algorithms which seek to improve convergence and reduce userworkload by partially automating the design of effective geometry control systems for aerodynamic shape optimization. These algorithms function by beginning in a coarse design space and periodically refining the geometry control with additional design variables when objective improvement becomes asymptotic. When refinement is initiated, progressive geometry control moves through a pre-defined sequence of increasingly fine geometry control schemes, while the adaptive algorithm instead dynamically generates a refined search space. This is accomplished by generating a list of candidate refinements and ranking them based on the minimum of a constrained quadratic suboptimization problem which constitutes an estimate of the maximum objective reduction possible in each candidate search space. The accuracy of this method is first validated on two inviscid problems, after which the progressive and adaptive algorithms are applied to two common aerodynamic shape optimization problems based on the Reynolds-Averaged Navier-Stokes equations, the twist and section optimization of the common research model wing-only geometry, and the planform optimization of a hybrid wing-body aircraft. In both cases, the dynamic geometry control schemes are able to converge to lower drag, often with fewer optimization iterations, compared to the tested static schemes.

关键词： Aerodynamic Shape Optimization Reynolds Averaged Navier Stokes adaptive algorithm Control Systems Control algorithm Broyden Fletcher Goldfarb Shanno Computational Fluid Dynamics Jetstream adaptive Control Lift Coefficient

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Efficient computation of frequency response for non-proportional damped systems

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ENGINEERING STRUCTURES 2022年 266卷 1页

作者： Wu, Baisheng Zhao, Xuqi Lim, C. W. Zhong, Huixiang Guangdong Univ Technol Sch Electromech Engn Guangzhou 510006 Peoples R China Jilin Normal Univ Sch Math Siping 136000 Peoples R China City Univ Hong Kong Dept Architecture & Civil Engn Kowloon Tat Chee Ave Hong Kong Peoples R China

Frequency response analysis is required in many structural dynamic applications. For large-scale problems, the cost of performing a frequency response analysis within a frequency interval of interest can be computationally very expensive and prohibitive, because the evaluation of the structural response for each excitation frequency requires solving a system with complex coefficients. For such purposes, a new method for the frequency response analysis of a non-proportional damped system in the frequency interval [0, omega(max)] is established. We first determine the lower-order modes in the interval [0, omega(max)/psi] and retain the quantity, where psi is an optional parameter which is greater than zero and less than 1. The default value of psi is set to 0.5. We then approximate the unknown higher-order mode contributions by using partial sums of the constructed convergent power series of excitation frequency. The number of items in the partial sum is determined adaptively by an iterative algorithm performed at omega(max). The resulting analytical expression for the frequency response is applied to the frequency interval [0, omega(max)]. Consequently, the frequency response analysis can be fulfilled simply by changing the excitation frequency in the analytical expression. Although the proposed method is derived based on the state space approach, its implementation is transformed to the original space to reduce the computational effort and storage space. The accuracy and effectiveness of the proposed method are illustrated and validated by two numerical examples.

关键词： adaptive algorithm Excitation frequency interval Frequency response Iteration Non-proportional damping

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adaptive algorithm to Improve Trajectory Prediction Accuracy of Climbing Aircraft

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JOURNAL OF GUIDANCE CONTROL AND DYNAMICS 2013年第1期36卷 15-24页

作者： Thipphavong, David P. Schultz, Charles A. Lee, Alan G. Chan, Steven H. NASA Ames Res Ctr Moffett Field CA 94035 USA Univ Affiliated Res Ctr Moffett Field CA 94035 USA

Aircraft climb trajectories are difficult to predict, and large errors in these predictions reduce the potential operational benefits of some advanced concepts in the Next Generation Air Transportation System. An algorithm that dynamically adjusts modeled aircraft weights based on observed track data to improve the accuracy of trajectory predictions for climbing flights has been developed. In real-time evaluation with actual Fort Worth Center traffic, the algorithm decreased the altitude root-mean-square error by about 20%. It also reduced the root-mean-square error of predicted time at top of climb by the same amount.

关键词： Boeing 777 Aircraft Performance Next Generation Air Transportation System adaptive algorithm Center TRACON Automation System Automatic Dependent Surveillance Broadcast RADAR Calibrated Airspeed En Route Automation Modernization Federal Aviation Administration

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