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An approach of motion compensation and ISAR imaging for micro-motion targets

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Journal of Systems Engineering and Electronics 2021年第1期32卷 68-80页

作者： WANG Yong ZHOU Xingyu LU xiaofei LI Yajun School of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China Jiuquan Satellite Launch Center Jiuquan 732750China Shanghai Radio Equipment Research Institute Shanghai 201109China

Inverse synthetic aperture radar(ISAR)imaging of the target with the non-rigid body is very important in the field of radar signal *** this paper,a motion compensation method combined with the preprocessing and global technique is proposed to reduce the influence of micro-motion components in the fast time domain,and the micro-Doppler(m-D)signal in the slow time domain is separated by the improved complex-valued empirical-mode decomposition(CEMD)algorithm,which makes the m-D signal more effectively distinguishable from the signal for the main body by translating the target to the Doppler ***,a better focused ISAR image of the target with the non-rigid body can be obtained *** of the simulated and raw data demonstrate the effectiveness of the algorithm.

关键词： inverse synthetic aperture radar(ISAR) micro-Doppler(m-D) motion compensation complex-valued empiricalmode decomposition(CEMD)

Vision‐audio fusion SLAM in dynamic environments

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CAAI Transactions on Intelligence Technology 2023年第4期8卷 1364-1373页

作者： Tianwei Zhang Huayan Zhang xiaofei Li Shenzhen Institute of Artificial Intelligence and Robotics for Society ShenzhenChina Department of Robotics Ritsumeikan UniversityShigaJapan Westlake University and Westlake Institute for Advanced Study HangzhouChina

Moving humans,agents,and subjects bring many challenges to robot self‐localisation and environment *** adapt to dynamic environments,SLAM researchers typically apply several deep learning image segmentation models to eliminate these moving ***,these moving obstacle segmentation methods cost too much computation resource for the onboard processing of mobile *** the current industrial environment,mobile robot collaboration scenario,the noise of mobile robots could be easily found by on‐board audio‐sensing processors and the direction of sound sources can be effectively acquired by sound source estimation algorithms,but the distance estimation of sound sources is ***,in the field of visual perception,the 3D structure information of the scene is relatively easy to obtain,but the recognition and segmentation of moving objects is more *** address these problems,a novel vision‐audio fusion method that combines sound source localisation methods with a visual SLAM scheme is proposed,thereby eliminating the effect of dynamic obstacles on multi‐agent *** heterogeneous robots experiments in different dynamic scenes indicate very stable self‐localisation and environment reconstruction performance of our method.

关键词： dynamic environment intelligent robots sensor fusion

A simplified bit metric calculation method for high-order PSK

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Science China(Information Sciences) 2013年第7期56卷 109-117页

作者： WANG Lei XU DaZhuan ZHANG xiaofei College of Information Science and Technology Nanjing University of Aeronautics and Astronautics

This paper proposes a simplified bit metric calculation method for high-order PSK signal with Gray-mapping. This method calculates the bit metric recursively by the symmetry of Gray code. Analysis and simulation results show that the proposed method can significantly reduce the computational complexity and maintain similar performance compared to ML and Max-Log bit metric. Additionally, this method generates bit metrics of PSK signals with different modulation order in the same way, so it can be applied to adaptive modulation system.

关键词： phase shift keying high order modulation bit metric soft demodulation

Robust state of charge estimation of lithium-ion battery via mixture kernel mean p-power error loss LSTM with heap-based-optimizer

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Journal of Energy Chemistry 2023年第5期80卷 768-784,I0016页

作者： Wentao Ma Yiming Lei xiaofei Wang Badong Chen School of Electrical Engineering Xi'an University of TechnologyXi’an 710048ShaanxiChina School of Microelectronics Xi'an Jiaotong UniversityXi’an 710049ShaanxiChina Institute of Artificial Intelligence and Robotics(IAIR) Xi'an Jiaotong UniversityXi’an 710049ShaanxiChina

The state of charge(SOC)estimation of lithium-ion battery is an important function in the battery management system(BMS)of electric *** long short term memory(LSTM)model can be employed for SOC estimation,which is capable of estimating the future changing states of a nonlinear *** the BMS usually works under complicated operating conditions,i.e the real measurement data used for model training may be corrupted by non-Gaussian noise,and thus the performance of the original LSTM with the mean square error(MSE)loss may ***,a novel LSTM with mixture kernel mean p-power error(MKMPE)loss,called MKMPE-LSTM,is developed by using the MKMPE loss to replace the MSE as the learning criterion in LSTM framework,which can achieve robust SOC estimation under the measurement data contaminated with non-Gaussian noises(or outliers)because of the MKMPE containing the p-order moments of the error *** addition,a meta-heuristic algorithm,called heap-based-optimizer(HBO),is employed to optimize the hyper-parameters(mainly including learning rate,number of hidden layer neuron and value of p in MKMPE)of the proposed MKMPE-LSTM model to further improve its flexibility and generalization performance,and a novel hybrid model(HBO-MKMPE-LSTM)is established for SOC estimation under non-Gaussian noise ***,several tests are performed under various cases through a benchmark to evaluate the performance of the proposed HBO-MKMPE-LSTM model,and the results demonstrate that the proposed hybrid method can provide a good robustness and accuracy under different non-Gaussian measurement noises,and the SOC estimation results in terms of mean square error(MSE),root MSE(RMSE),mean absolute relative error(MARE),and determination coefficient R2are less than 0.05%,3%,3%,and above 99.8%at 25℃,respectively.

关键词： SOC estimation Long short term memory model Mixture kernel mean p-power error Heap-based-optimizer Lithium-ion battery Non-Gaussian noisy measurement data

UCat: heterogeneous memory management for unikernels

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Frontiers of Computer Science 2023年第1期17卷 51-61页

作者： Chong TIAN Haikun LIU xiaofei LIAO Hai JIN National Engineering Research Center for Big Data Technology and System Services Computing Technology and System Lab/Cluster and Grid Computing LabSchool of Computing Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China

Unikernels provide an efficient and lightweight way to deploy cloud computing services in application-specialized and single-address-space virtual machines (VMs). They can efficiently deploy hundreds of unikernel-based VMs in a single physical server. In such a cloud computing platform, main memory is the primary bottleneck resource for high-density application deployment. Recently, non-volatile memory (NVM) technologies has become increasingly popular in cloud data centers because they can offer extremely large memory capacity at a low expense. However, there still remain many challenges to utilize NVMs for unikernel-based VMs, such as the difficulty of heterogeneous memory allocation and high performance overhead of address *** this paper, we present UCat, a heterogeneous memory management mechanism that support multi-grained memory allocation for unikernels. We propose front-end/back-end cooperative address space mapping to expose the host memory heterogeneity to unikernels. UCat exploits large pages to reduce the cost of two-layer address translation in virtualization environments, and leverages slab allocation to reduce memory waste due to internal memory fragmentation. We implement UCat based on a popular unikernel--OSv and conduct extensive experiments to evaluate its efficiency. Experimental results show that UCat can reduce the memory consumption of unikernels by 50% and TLB miss rate by 41%, and improve the throughput of real-world benchmarks such as memslap and YCSB by up to 18.5% and 14.8%, respectively.

关键词： unikernel virtualization non-volatile memory heterogeneous memory large page slab allocation

Adaptive Control of Discrete-time Nonlinear Systems Using ITF-ORVFL

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IEEE/CAA Journal of Automatica Sinica 2022年第3期9卷 556-563页

作者： xiaofei Zhang Hongbin Ma Wenchao Zuo Man Luo School of Automation Beijing Institute of TechnologyBeijing 100081 School of Vehicle and Mobility Tsinghua UniversityBeijing 100084China School of Automation Beijing Institute of Technologyand also with the State Key Laboratory of Intelligent Control and Decision of Complex Systems(Beijing Institute of Technology)Beijing 100081China School of Automation Beijing Institute of TechnologyBeijing 100081and he is with Beijing Institute of Electronic System EngineeringBeijing 100854China School of Automation Beijing Institute of TechnologyBeijing 100081and she is with Ant GroupBeijing 310013China

Random vector functional ink(RVFL)networks belong to a class of single hidden layer neural networks in which some parameters are randomly *** network structure in which contains the direct links between inputs and outputs is unique,and stability analysis and real-time performance are two difficulties of the control systems based on neural *** this paper,combining the advantages of RVFL and the ideas of online sequential extreme learning machine(OS-ELM)and initial-training-free online extreme learning machine(ITFOELM),a novel online learning algorithm which is named as initial-training-free online random vector functional link algo rithm(ITF-ORVFL)is investigated for training *** link vector of RVFL network can be analytically determined based on sequentially arriving data by ITF-ORVFL with a high learning speed,and the stability for nonlinear systems based on this learning algorithm is *** experiment results indicate that the proposed ITF-ORVFL is effective in coping with nonparametric uncertainty.

关键词： Adaptive control initial-training-free online learning algorithm random vector functional link networks

Resource abstraction and data placement for distributed hybrid memory pool

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Frontiers of Computer Science 2021年第3期15卷 47-57页

作者： Tingting CHEN Haikun LIU xiaofei LIAO Hai JIN National Engineering Research Center for Big Data Technology and System Services Computing Technology and System Lab/Gluster and Grid Computing LabSchool of Gomputing Science and TechnologyHuazhong University of Science and TechnologyWuhan 430074China

Emerging byte-addressable non-volatile memory(NVM)technologies offer higher density and lower cost than DRAM,at the expense of lower performance and limited write *** have been many studies on hybrid NVM/DRAM memory management in a single physical ***,it is still an open problem on how to manage hybrid memories efficiently in a distributed *** paper proposes Alloy,a memory resource abstraction and data placement strategy for an RDMA-enabled distributed hybrid memory pool(DHMP).Alloy provides simple APIs for applications to utilize DRAM or NVM resource in the DHMP,without being aware of the hardware details of the *** propose a hotness-aware data placement scheme,which combines hot data migration,data replication and write merging together to improve application performance and reduce the cost of *** evaluate Alloy with several micro-benchmark workloads and public benchmark *** results show that Alloy can significantly reduce the DRAM usage in the DHMP by up to 95%,while reducing the total memory access time by up to 57%compared with the state-of-the-art approaches.

关键词： load balance distributed hybrid memory clouds

Expectation-maximisation for speech source separation using convolutive transfer function

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CAAI Transactions on Intelligence Technology 2019年第1期4卷 47-53页

作者： xiaofei Li Laurent Girin Radu Horaud INRIA Grenoble Rhoe-Alpes Montbonnot Saint-MartinFrance GIPSA-lab Saint-Martin d’HèresFrance UniversitéGrenoble Alpes Saint-Martin d’HèresFrance

This study addresses the problem of under-determined speech source separation from multichannel microphone signals,*** convolutive mixtures of multiple *** time-domain signals are first transformed to the short-time Fourier transform(STFT)*** represent the room filters in the STFT domain,instead of the widely used narrowband assumption,the authors propose to use a more accurate model,*** convolutive transfer function(CTF).At each frequency band,the CTF coefficients of the mixing filters and the STFT coefficients of the sources are jointly estimated by maximising the likelihood of the microphone signals,which is resolved by an expectation-maximisation *** show that the proposed method provides very satisfactory performance under highly reverberant environments.

关键词： STFT CTF

UNILATERAL BIFURCATION FOR SEVERAL-PARAMETER EIGENVALUE PROBLEM WITH HOMOGENEOUS OPERATOR

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Acta Mathematica Scientia 2019年第5期39卷 1406-1414页

作者： xiaofei CAO Guowei DAI Faculty of Mathematics and Physics Huaiyin Institute of Technology Huaian 223003 China School of Mathematical Sciences Dalian University of Technology Dalian 116024 China

We establish the unilateral global bifurcation result for the following nonlinear operator equation u=L(λ)u + H(λ, u),(λ, u)∈ Rm×X where m is a positive integer, X is a Banach space, L(·) is a positively homogeneous completely continuous operator and H:R^m×X → X is completely continuous with H=o (||u||) near u=0 uniformly on bounded λ sets.

关键词： global bifurcation several-parameter nonlinear problem