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Smith Form of Triangular Multivariate Polynomial Matrix

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Journal of Systems Science & Complexity 2023年第1期36卷 151-164页

作者： LIU Jinwang WU Tao LI Dongmei school of Mathematics and computing sciences Hunan University of Science and TechnologyXiangtan 411201China

The Smith form of a matrix plays an important role in the equivalence of matrix.It is known that some multivariate polynomial matrices are not equivalent to their Smith forms.In this paper,the authors investigate mainly the Smith forms of multivariate polynomial triangular matrices and testify two upper multivariate polynomial triangular matrices are equivalent to their Smith forms respectively.

关键词： Degree-Lexicographical order equivalence of matrix multidimensional system multivariate polynomial matrix Smith form

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Multi-Distributed Speech Emotion Recognition Based on Mel Frequency Cepstogram and Parameter Transfer

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Chinese Journal of Electronics 2022年第1期31卷 155-167页

作者： LIN Long TAN Liang school of Computer Science Sichuan Normal University Institute of computing Technology Chinese Academy of Sciences

Speech emotion recognition(SER) is the use of speech signals to estimate the state of emotion. At present, machine learning is one of the main research methods of SER, the test and training data S of traditional machine learning all have the same distribution and feature space, but the data of speech is accessed from different environments and devices, with different distribution characteristics in real life. Thus, the traditional machine learning method is applied to the poor performance of SER. This paper proposes a multi-distributed SER method based on Mel frequency cepstogram(MFCC) and parameter transfer. The method is based on single-layer long short-term memory(LSTM), pre-trained inceptionv3 network and multi-distribution corpus. The speech pre-processed MFCC is taken as the input of single-layer LSTM, and input to the pre-trained inception-v3 network.The features are extracted through the pre-trained inception-v3 model. Then the features are sent to the newly defined the fully connected layer and classification layer,let the parameters of the fully connected layer be finetuned, finally get the classification result. The experiment proves that the method can effectively complete the classification of multi-distribution speech emotions and is more effective than the traditional machine learning framework of SER.

关键词： Speech emotion recognition (SER) Machine learning Mel frequency cepstogram (MFCC) Parameter transfer Long short-term memory (LSTM) Inception-v3

Extraction Security of Sequential Aggregate Signatures

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Chinese Journal of Electronics 2021年第5期30卷 885-894页

作者： ZHAI Jiaqi LIU Jian CHEN Lusheng school of Mathematical sciences Nankai University school of Cybersecurity College of Intelligence and ComputingTianjin University

Aggregate signature schemes enable anyone to compress many signatures into one.Besides the unforgeability of aggregate signature,another property called aggregate extraction sometimes is useful.In sequential aggregate signature schemes,the aggregate signature is computed incrementally by the signers.We introduce extraction security in the sequential context which can be seen as an analogy of aggregate extraction introduced by Boneh et al.in CRYPTO 2003.In addition to the practical meaning,it also has benefits in the construction of hierarchical identity-based signatures as we will point out.We study several well known aggregate signature schemes and prove some of them satisfy extraction security.

关键词： Cryptography Data security Digital signatures Sequential aggregate signatures Hierarchical identity-based signatures Aggregate extraction

A beamforming design for weighted sidelobe power leakage minimization

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Science China(Information sciences) 2016年第6期59卷 144-152页

作者： Cheng FENG Meng MA Bingli JIAO school of Electronics Engineering and computing sciences Peking University

In this paper, a beamforming scheme for minimizing the weighted sidelobe power leakage while maintaining the norm of the weight vector at unity is proposed. The proposed criterion is very flexible because weighting factors are added to the sidelobes in the object function, and the weighting factors can be adjusted according to any design purpose, e.g., to minimize the interference within a direction of arrival(Do A) range. To acquire the minimum sidelobe power leakage, we first express the sidelobe power through the sidelobe coefficient matrix. Afterwards, the minimization problem can be treated as the 2-norm minimization of the sidelobe coefficient matrix. The optimal weighting vector design is then derived by singular value decomposition(SVD).Simulation results show that the proposed beamformer can decrease the sidelobe power leakage and efficiently suppress interference with barely any increase in the sidelobes; moreover, this beamforming scheme provides good robustness in consideration of the DOA mismatch.

关键词： beamforming weighted sidelobe power leakage 2-norm singular value decomposition(SVD) direction of arrival(Do A)

A New Sixth-Order WENO Scheme for Solving Hyperbolic Conservation Laws

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Communications on Applied Mathematics and Computation 2023年第1期5卷 3-30页

作者： Kunlei Zhao Yulong Du Li Yuan State Key Laboratory of Scientific and Engineering computing(LSEC)and Institute of Computational Mathematics and Scientific/Engineering computing Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China school of Mathematical sciences University of Chinese Academy of SciencesBeijing 100190China school of Mathematical sciences Beihang UniversityBeijing 100191China

In this paper,we develop a new sixth-order WENO scheme by adopting a convex combina-tion of a sixth-order global reconstruction and four low-order local reconstructions.Unlike the classical WENO schemes,the associated linear weights of the new scheme can be any positive numbers with the only requirement that their sum equals one.Further,a very simple smoothness indicator for the global stencil is proposed.The new scheme can achieve sixth-order accuracy in smooth regions.Numerical tests in some one-and two-dimensional bench-mark problems show that the new scheme has a little bit higher resolution compared with the recently developed sixth-order WENO-Z6 scheme,and it is more efficient than the classical fifth-order WENO-JS5 scheme and the recently developed sixth-order WENO6-S scheme.

关键词： Global smoothness indicator Linear weights Sixth-order accuracy WENO

Regularized two-stage submodular maximization under streaming

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Science China(Information sciences) 2022年第4期65卷 102-111页

作者： Ruiqi YANG Dachuan XU Longkun GUO Dongmei ZHANG Beijing Institute for Scientific and Engineering computing Beijing University of Technology school of Mathematical sciences University of Chinese Academy Sciences school of Computer Science and Technology Qilu University of Technology school of Computer Science and Technology Shandong Jianzhu University

In the problem of maximizing regularized two-stage submodular functions in streams, we assemble a family ■ of m functions each of which is submodular and is visited in a streaming style that an element is visited for only once. The aim is to choose a subset S of size at most ■ from the element stream ■, so as to maximize the average maximum value of these functions restricted on S with a regularized modular term. The problem can be formally cast as ■, where c:■ is a non-negative modular function and ■ is a non-negative monotone non-decreasing submodular function. The well-studied regularized problem of ■ is exactly a special case of the above regularized two-stage submodular maximization by setting m=1 and ■=k. Although f(·)-c(·) is submodular, it is potentially negative and non-monotone and admits no constant multiplicative factor approximation. Therefore, we adopt a slightly weaker notion of approximation which constructs S such that f(S)-c(S)≥ρ·f(O)-c(O) holds against optimum solution O for some ρ∈(0, 1). Eventually, we devise a streaming algorithm by employing the distorted threshold technique, achieving a weaker approximation ratio with ρ=0.2996 for the discussed regularized two-stage model.

关键词： submodular maximization streaming model two-stage threshold technique approximation algorithms

The m-delay Autoregressive Model with Application

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Computer Modeling in Engineering & sciences 2020年第2期122卷 487-504页

作者： Manlika Ratchagit BenchawanWiwatanapataphee Nikolai Dokuchaev school of Electrical Engineering Computing and Mathematical SciencesCurtin UniversityPerthAustralia.

The classical autoregressive(AR)model has been widely applied to predict future data usingmpast observations over five decades.As the classical AR model required m unknown parameters,this paper implements the AR model by reducing m parameters to two parameters to obtain a new model with an optimal delay called as the m-delay AR model.We derive the m-delay AR formula for approximating two unknown parameters based on the least squares method and develop an algorithm to determine optimal delay based on a brute-force technique.The performance of them-delay AR model was tested by comparing with the classical AR model.The results,obtained from Monte Carlo simulation using the monthly mean minimum temperature in PerthWestern Australia from the Bureau of Meteorology,are no significant difference compared to those obtained from the classical AR model.This confirms that the m-delay AR model is an effective model for time series analysis.

关键词： Delay autoregressive model least squares method brute-force technique.

An oscillation-free Hermite WENO scheme for hyperbolic conservation laws

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Science China Mathematics 2024年第2期67卷 431-454页

作者： Zhuang Zhao Jianxian Qiu school of Mathematical sciences and Institute of Natural sciences Shanghai Jiao Tong UniversityShanghai 200240China school of Mathematical sciences and Fujian Provincial Key Laboratory of Mathematical Modeling and High-Performance Scientific computing Xiamen UniversityXiamen 361005China

In this paper, the sixth-order oscillation-free Hermite weighted essentially non-oscillatory (OFHWENO) scheme is proposed for hyperbolic conservation laws on structured meshes, where the zeroth- andfirst-order moments are the variables for the governing equations. The main difference from other HWENOschemes existing in the literature is that we add high-order numerical damping terms in the first-order momentequations to control spurious oscillations for the OF-HWENO scheme. The OF-HWENO scheme not only canachieve the designed optimal numerical order, but also can be easily implemented as we use only one set ofstencils in the reconstruction procedure and the same reconstructed polynomials are applied for the zeroth- andfirst-order moment equations. In order to obtain the adaptive order resolution when facing discontinuities, atransition polynomial is added in the reconstruction, where the associated linear weights can also be any positivenumbers as long as their summation equals one. In addition, the OF-HWENO scheme still keeps compactnessas only immediate neighbor values are needed in the space discretization. Some benchmark numerical tests areperformed to illustrate the high-order accuracy, high resolution and robustness of the proposed scheme.

关键词： Hermite WENO scheme hyperbolic conservation laws oscillation-free adaptive order discontinuous Galerkin method

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LOPE: A Low-Overhead Payment Verification Method for Blockchains

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Chinese Journal of Electronics 2021年第2期30卷 349-358页

作者： ZHANG Ying HE Zhengyuan JIA Linpeng DING Donghui ZHANG Hanwen SUN Yi school of Software Engineering Tongji University Blockchain Lab Institute of Computing Technology Chinese Academy of Sciences school of Computer Science and Technology University of Chinese Academy of Sciences

With its characteristics of decentralization,security, data traceability, and tamper-resistance, the blockchain has been widely used in various domains.Considering the difference in the performance of the devices, the light client is proposed so that devices without the ability to store a full blockchain copy can also participate in the blockchain transactions. However,the light client has to communicate with full nodes and verify the authenticity of a transaction which brings in some extent of communication, computation, and storage overheads to the light client. These overheads cannot be ignored for some low-performance devices, such as embedded devices or Io T chips, and therefore the current light client scheme does not work in this situation. We propose LOPE(a Low-overhead payment v Erification method) for poor-capacity nodes in the blockchain system.In LOPE, a grouping protocol is designed to partition full nodes into groups to serve the verification requests of the light client. In addition, Practical byzantine fault tolerance(PBFT) is used to ensure the light client to get a credible result in spite of a few dishonest nodes existing in the group. We conduct LOPE and evaluate it in a testbed. The experiment results show that LOPE reduces more than half of the communication overhead, degrades the computation overhead of the light client to a large extent, and avoids the storage overhead of the hash roots of block headers in the light client. We also conduct theoretical analysis to show the performance improvement and security issues of LOPE.

关键词： Blockchain Light client Low-overhead Payment verification