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Pattern-based learning and control of nonlinear pure-feedback systems with prescribed performance

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Science China(Information Sciences) 2023年第1期66卷 188-209页

作者： Fukai ZHANG weiming WU Cong wang Center for Intelligent Medical Engineering School of Control Science and EngineeringShandong University

This article presents a novel pattern-based intelligent control scheme with prescribed performance(PP) for uncertain pure-feedback systems operating in multiple control situations(patterns). Based on PP,an observer-based adaptive neural network(NN) control approach, which not only achieves system stability and prescribed tracking control performance but also realizes accurate identification/learning of the unknown closed-loop dynamics via deterministic learning and uses only one NN unit, is proposed. Subsequently, the knowledge learned is utilized to construct high-performance candidate controllers for each control situation.Based on the transformed system and observer technique, accurate classification of the nth order systems under different control situations is achieved by requiring only one set of dynamic estimators, thereby significantly reducing the complexity of pattern recognition. Thus, sudden changes in the control situation can be rapidly recognized based on the minimum residual principle, with which the correct candidate controller is selected to achieve superior control performance. The simulation results verify the efficacy of the proposed scheme.

关键词： adaptive neural control (ANC) deterministic learning neural networks (NNs) pattern-based control high gain observer pure-feedback systems

Global stability for an influenza transmission model incorporating human mobility behavior

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International Journal of Biomathematics 2017年第7期10卷 167-173页

作者： Yongli Cai Weiming Wang School of Mathematical Science Huaiyin Normal University Huaian 223300 P. R. China

A recent paper [W. D. wang. Modeling adaptive behavior in influenza transmission, Math. Model. Nat. Phenom. 7(3) (2012) 253-262] presented the local stability of the endemic equilibrium E* of an influenza transmission model incorporating hum an mobility behavior. In the present paper, we prove that PC is globally stable if the basic reproduction number R-0 > 1.

关键词： Influenza transmission basic reproduction number endemic global stability mobility Basic Reproduction Number Endemic Diseases Adaptive Behavior overall buckling influenza local stability

Dynamical pattern recognition for univariate time series and its application to an axial compressor

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Control Theory and Technology 2024年第1期22卷 39-55页

作者： Jingtao Hu weiming Wu Zejian Zhu Cong wang Center for Intelligent Medical Engineering School of Control Science and TechnologyShandong UniversityJinan250061ShandongChina School of Automation Science and Engineering South China University of TechnologyGuangzhou510641GuangdongChina

In this paper, a learning and recognition approach is proposed for univariate time series composed of output measurements of general nonlinear dynamical systems. Firstly, a class of dynamical systems in the canonical form is derived to describe the univariate time series by introducing coordinate transformation. An observer-based deterministic learning technique is then adopted to achieve dynamical modeling of the associated transformed systems of the training univariate time series, and the modeling results in the form of radial basis function network (RBFN) models are stored in a pattern library. Subsequently, multiple observer-based dynamical estimators containing the RBFN models in the pattern library are constructed for a test univariate time series, and a recognition decision scheme is proposed by the derived recognition indicator. On this basis, more concise recognition conditions are provided, which is beneficial for verifying the recognition results. Finally, simulation studies on the Rossler system and aero-engine stall warning verify the effectiveness of the proposed approach.

关键词： Dynamical pattern recognition Deterministic learning Stall warning Radial basis function network Sampled-data observer

Changes of vegetation in southern China

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Science China Earth Sciences 2019年第8期62卷 1316-1328页

作者： Weiming Wang Chunhai LI Junwu SHU Wei CHEN CAS Key Laboratory of Economic Stratigraphy and Palaeogeography Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing210008China State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing210008China

In order to reveal the changes of vegetation in southern China since the Last Glacial Maximum, we have established high-resolution time scales and palynological sequences of borehole profiles by drilling cores in some weak areas of the research to restore vegetation changes over the past 20,000 years on the basis of previous work. This paper gives the vegetation zoning maps of 18, 9 and 6 ka BP respectively in southern China, and describes the distribution characteristics of plants in different zones/subzones. The results show that the vegetation zonations around 18 ka BP were significantly different from that at present.It appeared in turn with Cold-temperate coniferous forest and alpine meadow steppe zone, and Temperate mixed coniferous and broad-leaved forest zone/warm temperate deciduous broad-leaved forest zone from northwest to southeast in the west, and Temperate mixed coniferous and broad-leaved forest zone, Warm temperate deciduous broad-leaved forest zone, and Northern subtropical mixed evergreen and deciduous broad-leaved forest zone from north to south in the central and east. The vegetation distribution around 9 ka BP changed distinctively. Except that the northwest part was located in Mountain temperate mixed coniferous and broad-leaved forest zone, the vegetation in other areas occurred in turn with North subtropical mixed evergreen and deciduous broad-leaved forest subzone, Mid-subtropical typical evergreen broad-leaved forest subzone, and South subtropical monsoon evergreen broad-leaved forest subzone/Tropical seasonal rainforest and rainforest zone from north to south.There was little change in the appearance of vegetation zonations between 6 and 9 ka BP, but the northern edge of each vegetation belt moved a little northward, reflecting that the overall climate became warmer around 6 ka BP. The vegetation changes in southern China over the past 20,000 years were largely driven by environmental changes. Climate change was the main factor affecting the vegetation distribution. The impact of human

关键词： Vegetation changes 18 ka BP 9 ka BP 6 ka BP Environmental change Southern China

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Anterior cruciate ligament reconstruction with femoral direct fiber insertion: a novel technique

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Chinese Medical Journal 2022年第2期135卷 231-233页

作者： Xianxiang Xiang Rongjin Chen Ruixin Li Jue Gong Jiang Yang Chunhui Li Weiming Wang Department of Sports Medicine The Affiliated Zhongshan Hospital of Dalian UniversityDalianLiaoning 116001China Department of Orthopedic Surgery The Affiliated Rehabilitation Hospital of Chengdu University of Traditional Chinese MedicineChengduSichuan 611130China Department of Sports Medicine The Affiliated Xinhua Hospital of Dalian UniversityDalianLiaoning 116021China

Anterior cruciate ligament(ACL)tear is a common disease among sports-medicine outpatients.To restore static and dynamic stability as well as kinematics in an ACL injured knee,accurate position of the femoral and tibial tunnel plays an important role in ACL reconstruction,especially the femoral tunnel.[1]Some studies have attempted to maximize functional outcome of anteriomedial(AM)and posterolateral(PL)bundles by reconstructing ACL in the center of the entire femoral footprint[2,3].

关键词： femoral ligament medial

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Towards harmonized regional style transfer and manipulation for facial images

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Computational Visual Media 2023年第2期9卷 351-366页

作者： Cong wang Fan Tang Yong Zhang Tieru Wu weiming Dong School of Mathematics Jilin UniversityChangchun 130012China School of Artificial Intelligence Jilin UniversityChangchun 130012China AI Lab TencentShenzhen 518054China Institute of Automation Chinese Academy of SciencesBeijing 100190China

Regional facial image synthesis conditioned on a semantic mask has achieved great attention in the field of computational visual media.However,the appearances of different regions may be inconsistent with each other after performing regional editing.In this paper,we focus on harmonized regional style transfer for facial images.A multi-scale encoder is proposed for accurate style code extraction.The key part of our work is a multi-region style attention module.It adapts multiple regional style embeddings from a reference image to a target image,to generate a harmonious result.We also propose style mapping networks for multi-modal style synthesis.We further employ an invertible flow model which can serve as mapping network to fine-tune the style code by inverting the code to latent space.Experiments on three widely used face datasets were used to evaluate our model by transferring regional facial appearance between datasets.The results show that our model can reliably perform style transfer and multimodal manipulation,generating output comparable to the state of the art.

关键词： face manipulation style transfer generative models facial harmonization

Rapid dynamical pattern recognition for sampling sequences

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Science China(Information Sciences) 2021年第3期64卷 118-135页

作者： weiming WU Qian wang Chengzhi YUAN Cong wang School of Automation Science and Engineering South China University of Technology School of Control Science and Engineering Shandong University Department of Mechanical Industrial and Systems Engineering University of Rhode Island

In this paper, based on deterministic learning, we propose a method for rapid recognition of dynamical patterns consisting of sampling sequences. First, for the sequences yielded by sampling a periodic or recurrent trajectory(a dynamical pattern) generated from a nonlinear dynamical system, a sampled-data deterministic learning algorithm is employed for modeling/identification of inherent system dynamics. Second,a definition is formulated to characterize similarities between sampling sequences(dynamical patterns) based on differences in the system dynamics. Third, by constructing a set of discrete-time dynamical estimators based on the learned knowledge, similarities between the test and training patterns are measured by using the average L1 norms of synchronization errors, and general conditions for accurate and rapid recognition of dynamical patterns are given in a sampled-data framework. Finally, numerical examples are discussed to illustrate the effectiveness of the proposed method. We demonstrate that not only a test pattern can be rapidly recognized corresponding to a similar training pattern, but also the proposed recognition conditions can be verified step by step based on historical sampling data. This makes a distinction compared with the previous work on rapid dynamical pattern recognition for continuous-time nonlinear systems, in which the recognition conditions are difficult to be verified by using continuous-time signals.

关键词： deterministic learning dynamical pattern recognition sampling sequence synchronization

Deep 3D mesh watermarking with self-adaptive robustness

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Cybersecurity 2023年第2期6卷 75-88页

作者： Feng wang Hang Zhou Han Fang weiming Zhang Nenghai Yu University of Science and Technology of China HefeiChina Simon Fraser University VancouverCanada National University of Singapore Kent RidgeSingapore

Robust 3D mesh watermarking is a traditional research topic in computer graphics,which provides an efficient solution to the copyright protection for 3D meshes.Traditionally,researchers need manually design watermarking algorithms to achieve suffcient robustness for the actual application scenarios.In this paper,we propose the first deep learning-based 3D mesh watermarking network,which can provide a more general framework for this problem.In detail,we propose an end-to-end network,consisting of a watermark embedding sub-network,a watermark extracting sub-network and attack layers.We employ the topology-agnostic graph convolutional network(GCN)as the basic convolution operation,therefore our network is not limited by registered meshes(which share a fixed topology).For the specific application scenario,we can integrate the corresponding attack layers to guarantee adaptive robustness against possible attacks.To ensure the visual quality of watermarked 3D meshes,we design the curvature consistency loss function to constrain the local geometry smoothness of watermarked meshes.Experimental results show that the proposed method can achieve more universal robustness while guaranteeing comparable visual quality.

关键词： 3D mesh watermarking Graph convolution network Attack layer

Quantitative analysis of parameters’influence on the stability of coal roadway clamped by upper and lower soft rock with extra thickness

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International Journal of Modeling, Simulation, and Scientific Computing 2014年第2期5卷 25-39页

作者： Zenghui Zhao Weiming Wang Jixing Yan College of Civil Engineering of Shandong University of Science and Technology Qingdao Shandong 266590P.R.China

In this paper,a physical model of coal roadway which is clamped by upper and lower softrock with extra thickness was built according to the characteristics of soft rock strata in china's western mining area.Then,a series of orthogonal numerical experiments were carried out by selecting the strength and stiffness parameters of soft rock and coal seam as well as the in situ stress of soft rock strata as experimental factors and roadway displacements(convergence displacements of sides,displacement of roof to floor)as experimental indexes.By constructing the F statistics with different inspection levels,evaluation method for influence of the experimental factors on stability indexes were defined.Thus,influence degrees of specified parameters on the stability of roadway were divided into five classes as follows:highly significant influence,significant influence,relatively significant influence,little significant influence,and no influence respectively which realize the quantitative analysis of the influence degrees of experimental factors.The finite element calculation results showed that main failure mode of coal roadway that usually showed as tension failure of coal seam in roof and deformation factors of coal seam had the most remarkable effect on roadway displacements.The conclusions provide theoretical basis for further analysis of the mechanism of"roof burst"in roadway maintenance.

关键词： Upper and lower soft rock with extra thickness coal roadway orthogonal experiment stability influence degree quantitative analysis