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Maximum Correntropy High-Order Extended Kalman Filter

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Chinese Journal of Electronics 2022年第1期31卷 190-198页

In this paper, a novel maximum correntropy high-order extended Kalman filter(H-MCEKF) is proposed for a class of nonlinear non-Gaussian systems presented by polynomial form. All high-order polynomial terms in the state model are defined as implicit variables and regarded as parameter variables; the original state model is equivalently formulated into a pseudo-linear form with original variables and parameter variables; the dynamic relationship between each implicit variable and all variables is modeled, then an augmented linear state model appears by combing with pseudo-linear state model; similarly, the nonlinear measurement model can be equivalently rewritten into linear form; once again, the statistical characteristics of non-Gaussian modeling error are described by mean value and variance based on their finite samples; combing original measurement model with predicted value regarded as added state measurement, a cost function to solve the state estimation based on maximum correntropy criterion(MCC) is constructed; on the basis of this cost function, the state estimation problem can be equivalently converted into a recursive solution problem in the form of Kalman filter, in which the filter gain matrix is solved by numerical iteration though its fixed-point equation; illustration examples are presented to demonstrate the effectiveness of the new algorithm.

关键词： cost function filter gain matrix numerical iteration matrix algebra state estimation polynomial form nonlinear measurement nonGaussian modeling error Kalman filters nonGaussian systems sampling methods pseudolinear state model recursive solution problem statistical characteristics state measurement polynomials maximum entropy methods implicit variables high-order polynomial terms H-MCEKF nonlinear filters augmented linear state model MCC pseudolinear form parameter variables maximum correntropy high-order extended Kalman filter fixed-point equation iterative methods maximum correntropy criterion finite samples

A Novel Step-by-Step High-Order Extended Kalman Filter Design for a Class of Complex Systems with Multiple Basic Multipliers

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Chinese Journal of Electronics 2021年第2期30卷 313-321页

A novel step-by-step linearization high-order Extended Kalman filter SH-EKF is designed for a class of nonlinear systems composed of linear functions and the product of several separable basic functions. The basic functions in the state and measurement models are defined as latent variables; the state and measurement models are equivalently formulated into pseudo-linear models based on the combination of the original variable and the latent variables; latent variables are regarded as new variables,and a dynamic linear model between each latent variable and other latent variables with original state is established;the measurement model is rewritten into the first-order linear product form between the current state and each latent variable; latent variables are solved by Kalman filter step by step, and a stepwise linearized high-order extended Kalman filter is designed. Illustration examples are presented to demonstrate the effectiveness of the new algorithm.

关键词： step-by-step linearization high-order Extended Kalman filter SH-EKF latent variables first-order linear product form multiple basic multipliers Kalman filter step dynamic linear model nonlinear filters measurement model original variable linear functions Kalman filters separable basic functions measurement models Kalman filter design novel step-by-step high-order pseudolinear models

The Heisenberg double of the quantum Euclidean group and its representations

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Science China Mathematics 2023年第8期66卷 1713-1736页

作者： wen-Qing tao School of Mathematical Science Yangzhou UniversityYangzhou 225002China

The Heisenberg double D_(q)(E_(2))of the quantum Euclidean group O_(q)(E_(2))is the smash product of O_(q)(E_(2))with its Hopf dual U_(q)(e_(2)).For the algebra D_(q)(E_(2)),explicit descriptions of its prime,primitive and maximal spectra are *** the prime factors of D_(q)(E_(2))are presented as generalized Weyl *** a result,we obtain that the algebra D_(q)(E_(2))has no finite-dimensional representations,and D_(q)(E_(2))cannot have a Hopf algebra *** automorphism groups of the quantum Euclidean group and its Heisenberg double are *** centralizers are explicitly described via generators and defining *** enables us to give a classification of simple weight modules and the so-called a-weight modules over the algebra D_(q)(E_(2)).

关键词： Heisenberg double quantum Euclidean group automorphism group prime ideal weight module

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Metadata Feedback and Utilization for Data Deduplication Across WAN

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Journal of Computer Science & Technology 2016年第3期31卷 604-623页

作者： Bing Zhou Jiang-tao wen State Key Laboratory on Intelligent Technology and Systems Tsinghua University Beijing 100084 China Tsinghua National Laboratory for Information Science and Technology Tsinghua University Beijing 100084 China Department of Computer Science and Technology Tsinghua University Beijing 100084 China

Data deduplication for file communication across wide area network （WAN） in the applications such as file synchronization and mirroring of cloud environments usually achieves significant bandwidth saving at the cost of significant time overheads of data deduplication. The time overheads include the time required for data deduplication at two geographi- cally distributed nodes （e.g., disk access bottleneck） and the duplication query/answer operations between the sender and the receiver, since each query or answer introduces at least one round-trip time （RTT） of latency. In this paper, we present a data deduplication system across WAN with metadata feedback and metadata utilization （MFMU）, in order to harness the data deduplication related time overheads. In the proposed MFMU system, selective metadata feedbacks from the receiver to the sender are introduced to reduce the number of duplication query/answer operations. In addition, to harness the metadata related disk I/O operations at the receiver, as well as the bandwidth overhead introduced by the metadata feedbacks, a hysteresis hash re-chunking mechanism based metadata utilization component is introduced. Our experimental results demonstrated that MFMU achieved an average of 20%~40% deduplication acceleration with the bandwidth saving ratio not reduced by the metadata feedbacks, as compared with the ＂baseline＂ content defined chunking （CDC） used in LBFS （Low-bandwith Network File system） and exiting state-of-the-art Bimodal chunking algorithms based data deduplication solutions.

关键词： data deduplication wide area network (WAN) metadata feedback metadata utilization

A Data Deduplication Framework of Disk Images with Adaptive Block Skipping

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Journal of Computer Science & Technology 2016年第4期31卷 820-835页

作者： Bing Zhou Jiang-tao wen State Key Laboratory on Intelligent Technology and Systems Tsinghua University Beijing 100084 China

We describe an efficient and easily applicable data deduplication framework with heuristic prediction based adaptive block skipping for the real-world dataset such as disk images to save deduplication related overheads and improve deduplication throughput with good deduplication efficiency maintained. Under the framework, deduplication operations are skipped for data chunks determined as likely non-duplicates via heuristic prediction, in conjunction with a hit and matching extension process for duplication identification within skipped blocks and a hysteresis mechanism based hash indexing process to update the hash indices for the re-encountered skipped chunks. For performance evaluation, the proposed framework was integrated and implemented in the existing data domain and sparse indexing deduplication algorithms. The experimental results based on a real-world dataset of 1.0 TB disk images showed that the deduplication related overheads were significantly reduced with adaptive block skipping, leading to a 30%-80% improvement in deduplication throughput when deduplieation mctadata were stored on the disk for data domain, and 25%-40% RAM space saving with a 15%-20% improvement in deduplication throughput when an in-RAM sparse index was used in sparse indexing. In both cases, the corresponding deduplication ratios reduced were below 5%.

关键词： data deduplication metadata adaptive block skipping

Improving Metadata Caching Efficiency for Data Deduplication via In-RAM Metadata Utilization

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Journal of Computer Science & Technology 2016年第4期31卷 805-819页

We describe a data deduplication system for backup storage of PC disk images, named in-RAM metadata utilizing deduplication （IRwMUD）. In-RAM hash granularity adaptation and miniLZO based data compression are firstly proposed to reduce the in-RAM metadata size and thereby reduce the space overheads required by the in-RAM metadata caches. Secondly, an in-RAM metadata write cache, as opposed to the traditional metadata read cache, is proposed for further reducing metadata-related disk I/O operations and improving deduplication throughput. During deduplication, the metadata write cache is managed following the LRU caching policy. For each manifest that is hit in the metadata write cache, an expensive manifest reloading operation from the disk is avoided. After deduplieation, all the manifests in the metadata write cache are cleared and stored on the disk. Our experimental results using 1.5 TB real-world disk image dataset show that I） IR-MUD achieved about 95% size reduction for the deduplication metadata, with a small time overhead introduced, 2） when the metadata write cache was not utilized, with the same RAM space size for the metadata read cache, IR-MUD achieved a 400% higher RAM hit ratio and a 50% higher deduplication throughput, as compared with the classic Sparse Indexing deduplication system where no metadata utilization approaches are utilized, and 3） when the metadata write cache was utilized and enough RAM space was available, IR-MUD achieved a 500% higher RAM hit ratio compared with Sparse Indexing and a 70% higher deduplication throughput compared with IR-MUD with only a single metadata read cache. The in-RAM metadata harnessing and metadata write caching approaches of IR-MUD can be applied in most parallel deduplication systems for improving metadata caching efficiency.

关键词： data deduplication cache metadata utilization

Coupling potential and viscous flow models with domain decomposition for wave propagations

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Journal of Hydrodynamics 2022年第5期34卷 826-848页

作者： wen-jie Zhong wen-tao Wang De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China China Ship Scientific Research Center Wuxi214082China

Either potential flow or viscous flow based model may be flawed for numerical wave *** two-way coupling of potential and viscous flow models with the domain decomposition utilizing respective strengths has been a trending research *** contrast to existing literatures in which closed source potential models were used,the widely used open source OceanWave3D,OpenFOAM-v2012 are used in the present *** innovative overlapping two-way coupling strategy is developed utilizing the ghost points in *** guarantee computational stability,a relaxation zone used both for outlet damping and data transfer is built over the overlapping region in *** free surface elevation in the relaxation zone is directly probed in OpenFOAM while the velocity potential is indirectly built upon its temporal variation which is calculated by the free surface boundary condition using the probed *** coupling is achieved based on the fourth-order Runge-Kutta(RK)*** two-and three-dimensional tests including linear,nonlinear,irregular,and multi-directional irregular waves,are *** effectiveness of the coupling procedure in bidirectional data transfer is fully demonstrated,and the model is validated to be accurate and efficient,thus providing a competitive alternative for ocean wave simulations.

关键词： Domain decomposition numerical wave tank potential/viscous flow coupling irregular waves wave-structure interaction

High-Order Extended Strong Tracking Filter

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Chinese Journal of Electronics 2021年第6期30卷 1152-1158页

作者： SUN Xiaohui wen tao wen Chenglin CHENG Xingshuo WU Yunkai School of Automation Hangzhou Dianzi University School of Electronic and Information Engineering Beijing Jiaotong University School of Automation Guangdong University of Petrochemical Technology School of Mechatronic Engineering and Automation Foshan University School of Electronics and Information Jiangsu University of Science and Technology

A novel High-order extended Strong tracking filter(H-STF) is proposed for a class of nonlinear systems. All high-order polynomial terms in the state model are regarded as implicit variables; the original state model is equivalently formulated into a pseudo-linear form; the dynamic relationship between each implicit variable and all variables is modeled; original state model is rewritten into an augmented linear model; the nonlinear measurement model can be rewritten into linear form;taking into account the problems of modeling errors and state mutations that may be caused by the introduction of implicit variables, a high-order extended strong tracking filter is designed. Examples are presented to demonstrate the effectiveness of the new algorithm.

关键词： state mutations high-order polynomial terms augmented linear model polynomials nonlinear control systems Kalman filters target tracking nonlinear measurement model high-order extended strong tracking filter pseudolinear form tracking filters nonlinear systems

A Novel Integrated Path Planning Algorithm for Warehouse AGVs

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Chinese Journal of Electronics 2021年第2期30卷 331-338页

作者： wen tao YANG Daichuan LIU Weifeng wen Chenglin CAI Baigen School of Electronic and Information Engineering Beijing Jiaotong University School of Automation Hangzhou Dianzi University

We propose an integrated path planning method for multiple automated guided vehicles performing logistics delivery within a real-world warehouse environment considering obstacles. By applying it on each vehicle,this proposed method enables the vehicle the vehicles have the capabilities for autonomous path planning. The path planning consists of three parts, K-means algorithm based task points clustering, genetic algorithm based task points ordering, and the probabilistic road map based best path search. Vehicle conflict resolution is depending on implementing the probabilistic road map construction considering the realistic map with *** simulations result validate that the clustering and ordering are necessary for the path planning, both the path planning time and the Automated guided vehicles(AGVs)running time can be dramatically reduced.

关键词： path planning time vehicle conflict resolution real-world warehouse environment probabilistic road map construction path planning collision avoidance integrated path planning method mobile robots autonomous path planning genetic algorithm algorithm based task points path search vehicles running time novel integrated path planning algorithm logistics genetic algorithms automatic guided vehicles multiple automated guided vehicles logistics delivery