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Simulation and Field Testing of Multiple Vehicles Collision Avoidance Algorithms 被引量:9
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作者 Chaoyue Zu Chao Yang +3 位作者 Jian Wang Wenbin Gao Dongpu Cao Fei-Yue Wang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2020年第4期1045-1063,共19页
A global planning algorithm for intelligent vehicles is designed based on the A* algorithm, which provides intelligent vehicles with a global path towards their destinations. A distributed real-time multiple vehicle c... A global planning algorithm for intelligent vehicles is designed based on the A* algorithm, which provides intelligent vehicles with a global path towards their destinations. A distributed real-time multiple vehicle collision avoidance(MVCA)algorithm is proposed by extending the reciprocal n-body collision avoidance method. MVCA enables the intelligent vehicles to choose their destinations and control inputs independently,without needing to negotiate with each other or with the coordinator. Compared to the centralized trajectory-planning algorithm, MVCA reduces computation costs and greatly improves the robustness of the system. Because the destination of each intelligent vehicle can be regarded as private, which can be protected by MVCA, at the same time MVCA can provide a real-time trajectory planning for intelligent vehicles. Therefore,MVCA can better improve the safety of intelligent vehicles. The simulation was conducted in MATLAB, including crossroads scene simulation and circular exchange position simulation. The results show that MVCA behaves safely and reliably. The effects of latency and packet loss on MVCA are also statistically investigated through theoretically formulating broadcasting process based on one-dimensional Markov chain. The results uncover that the tolerant delay should not exceed the half of deciding cycle of trajectory planning, and shortening the sending interval could alleviate the negative effects caused by the packet loss to an extent. The cases of short delay(< 100100 ms) and low packet loss(< 5%) can bring little influence to those trajectory planning algorithms that only depend on V2 V to sense the context, but the unpredictable collision may occur if the delay and packet loss are further worsened. The MVCA was also tested by a real intelligent vehicle, the test results prove the operability of MVCA. 展开更多
关键词 Collision avoidance intelligent vehicles intervehicle communication SIMULATION TESTING trajectory planning
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Fano resonance and wave transmission through a chain structure with an isolated ring composed of defects
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作者 张存喜 丁秀欢 +2 位作者 王瑞 周运清 孔令民 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第3期212-217,共6页
We consider a discrete model that describes a linear chain of particles coupled to an isolated ring composed of N defects. This simple system can be regarded as a generalization of the familiar Fano Anderson model. It... We consider a discrete model that describes a linear chain of particles coupled to an isolated ring composed of N defects. This simple system can be regarded as a generalization of the familiar Fano Anderson model. It can be used to model discrete networks of coupled defect modes in photonic crystals and simple waveguide arrays in two-dimensional lattices. The analytical result of the transmission coefficient is obtained, along with the conditions for perfect reflections and transmissions due to either destructive or constructive interferences. Using a simple example, we further investigate the relationship between the resonant frequencies and the number of defects N, and study how to affect the numbers of perfect reflections and transmissions. In addition, we demonstrate how these resonance transmissions and refections can be tuned by one nonlinear defect of the network that possesses a nonlinear Kerr-like response. 展开更多
关键词 wave transmission Fano resonance DEFECT BISTABILITY
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Painlevé Property and Integrability of Polynomial Dynamical Systems
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作者 Li Wen-lei Shi Shao-yun 《Communications in Mathematical Research》 CSCD 2014年第4期358-368,共11页
The main purpose of this paper is to investigate the connection between the Painlev′e property and the integrability of polynomial dynamical systems. We show that if a polynomial dynamical system has Painlev′e prope... The main purpose of this paper is to investigate the connection between the Painlev′e property and the integrability of polynomial dynamical systems. We show that if a polynomial dynamical system has Painlev′e property, then it admits certain class of first integrals. We also present some relationships between the Painlev′e property and the structure of the differential Galois group of the corresponding variational equations along some complex integral curve. 展开更多
关键词 Painlev′e property INTEGRABILITY differential Galois group
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Bionic Mosaic Method of Panoramic Image Based on Compound Eye of Fly 被引量:8
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作者 Haipeng Chen Xuanjing Shen +1 位作者 Xiaofei Li Yushan Jin 《Journal of Bionic Engineering》 SCIE EI CSCD 2011年第4期440-448,共9页
To satisfy the requirements of real-time and high quality mosaics, a bionic compound eye visual system was designed by simulating the visual mechanism of a fly compound eye. Several CCD cameras were used in this syste... To satisfy the requirements of real-time and high quality mosaics, a bionic compound eye visual system was designed by simulating the visual mechanism of a fly compound eye. Several CCD cameras were used in this system to imitate the small eyes of a compound eye. Based on the optical analysis of this system, a direct panoramic image mosaic algorithm was proposed. Several sub-images were collected by the bionic compound eye visual system, and then the system obtained the overlapping proportions of these sub-images and cut the overlap sections of the neighboring images. Thus, a panoramic image with a large field of view was directly mosaicked, which expanded the field and guaranteed the high resolution. The experimental results show that the time consumed by the direct mosaic algorithm is only 2.2% of that by the traditional image mosaic algorithm while guaranteeing mosaic quality. Furthermore, the proposed method effectively solved the problem of misalignment of the mosaic image and eliminated mosaic cracks as a result of the illumination factor and other factors. This method has better real-time properties compared to other methods. 展开更多
关键词 bionic compound eye panoramic image image mosaic direct mosaic algorithm
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Generalized Extended tanh-function Method for Traveling Wave Solutions of Nonlinear Physical Equations 被引量:6
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作者 CHANG JING GAO YI-XIAN AND CAI HUA 《Communications in Mathematical Research》 CSCD 2014年第1期60-70,共11页
In this paper, the generalized extended tanh-function method is used for constructing the traveling wave solutions of nonlinear evolution equations. We choose Fisher's equation, the nonlinear schr&#168;odinger equat... In this paper, the generalized extended tanh-function method is used for constructing the traveling wave solutions of nonlinear evolution equations. We choose Fisher's equation, the nonlinear schr&#168;odinger equation to illustrate the validity and ad-vantages of the method. Many new and more general traveling wave solutions are obtained. Furthermore, this method can also be applied to other nonlinear equations in physics. 展开更多
关键词 generalized tanh-function method nonlinear Schrodinger equation Fisher's equation
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Processing of 3D meshed surfaces using spherical wavelets 被引量:4
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作者 Hu Jianping Liu Xiuping +1 位作者 WangXiaochao and Xie Qi 《Computer Aided Drafting,Design and Manufacturing》 2012年第1期20-26,共7页
This paper presents an efficient technique for processing of 3D meshed surfaces via spherical wavelets. More specifically, an input 3D mesh is firstly transformed into a spherical vector signal by a fast low distortio... This paper presents an efficient technique for processing of 3D meshed surfaces via spherical wavelets. More specifically, an input 3D mesh is firstly transformed into a spherical vector signal by a fast low distortion spherical parameterization approach based on symmetry analysis of 3D meshes. This signal is then sampled on the sphere with the help of an adaptive sampling scheme. Finally, the sampled signal is transformed into the wavelet domain according to spherical wavelet transform where many 3D mesh processing operations can be implemented such as smoothing, enhancement, compression, and so on. Our main contribution lies in incorporating a fast low distortion spherical parameterization approach and an adaptive sampling scheme into the frame for pro- cessing 3D meshed surfaces by spherical wavelets, which can handle surfaces with complex shapes. A number of experimental ex- amples demonstrate that our algorithm is robust and efficient. 展开更多
关键词 mesh processing spherical parameterization adaptive sampling spherical wavelets
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A Novel Method for Prediction of Protein Domain Using Distance-Based Maximal Entropy
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作者 Shu-xue Zou Yan-xin Huang Yan Wang Chun-guang Zhou 《Journal of Bionic Engineering》 SCIE EI CSCD 2008年第3期215-223,共9页
Detecting the boundaries of protein domains is an important and challenging task in both experimental and computational structural biology. In this paper, a promising method for detecting the domain structure of a pro... Detecting the boundaries of protein domains is an important and challenging task in both experimental and computational structural biology. In this paper, a promising method for detecting the domain structure of a protein from sequence information alone is presented. The method is based on analyzing multiple sequence alignments derived from a database search. Multiple measures are defined to quantify the domain information content of each position along the sequence. Then they are combined into a single predictor using support vector machine. What is more important, the domain detection is first taken as an imbal- anced data learning problem. A novel undersampling method is proposed on distance-based maximal entropy in the feature space of Support Vector Machine (SVM). The overall precision is about 80%. Simulation results demonstrate that the method can help not only in predicting the complete 3D structure of a protein but also in the machine learning system on general im- balanced datasets. 展开更多
关键词 protein domain boundary SVM imbalanced data learning distance-based maximal entropy
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Prediction of miRNA Based on miRNA Biogenesis via One-class SVM
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作者 LIU Yuan-ning YAN Wen +3 位作者 ZHANG Hao LI Zhi LU Hui-jun LI Xin 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2010年第5期803-809,共7页
MicroRNAs are a class of small, single-stranded RNAs which are produced by non-protein-coding RNA genes with a length of 21-29 nt. They regulate the expression of protein-encoding genes at the post-transcriptional lev... MicroRNAs are a class of small, single-stranded RNAs which are produced by non-protein-coding RNA genes with a length of 21-29 nt. They regulate the expression of protein-encoding genes at the post-transcriptional level and the degradation ofmRNAs by base pairing to mRNAs. Mature miRNAs are processed from 60-90 nt RNA hairpin structures called pre-miRNAs. At present, most of the machine learning computational methods for pre-miRNAs prediction are based on two-class SVM and use structural information of pre-miRNA hairpins. Those methods share a common feature that all of them need a negative dataset in the training dataset and feature selection in both training and testing dataset. In order to avoid selecting false negative examples of miRNA hairpins in the training dataset which may mislead the classifiers, we presented a microRNA prediction algorithm called MirBio based on miRNAs Biogenesis which is trained only on the information of the positive miRNAs class to predict miRNAs. It can predict both pre-miRNAs and miRNAs and get a relatively satisfying result in this study. 展开更多
关键词 MIRNAS HAIRPIN One-class classification miRNAs Biogenesis
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Strengthened Initialization of Adaptive Cross-Generation Differential Evolution
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作者 Wei Wan Gaige Wang Junyu Dong 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第3期1495-1516,共22页
Adaptive Cross-Generation Differential Evolution(ACGDE)is a recently-introduced algorithm for solving multiobjective problems with remarkable performance compared to other evolutionary algorithms(EAs).However,its conv... Adaptive Cross-Generation Differential Evolution(ACGDE)is a recently-introduced algorithm for solving multiobjective problems with remarkable performance compared to other evolutionary algorithms(EAs).However,its convergence and diversity are not satisfactory compared with the latest algorithms.In order to adapt to the current environment,ACGDE requires improvements in many aspects,such as its initialization and mutant operator.In this paper,an enhanced version is proposed,namely SIACGDE.It incorporates a strengthened initialization strategy and optimized parameters in contrast to its predecessor.These improvements make the direction of crossgeneration mutation more clearly and the ability of searching more efficiently.The experiments show that the new algorithm has better diversity and improves convergence to a certain extent.At the same time,SIACGDE outperforms other state-of-the-art algorithms on four metrics of 24 test problems. 展开更多
关键词 Differential Evolution(DE) multi-objective optimization(MO) opposition-based learning parameter adaptation
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Automatic localization of macular area based on structure label transfer
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作者 Xiao-Xin Guo Qun Li +1 位作者 Chao Sun Yi-Nan LU 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2018年第3期422-428,共7页
AIM: To explore feasibility and practicability of macula localization independent of macular morphological features. METHODS: A novel method was proposed to identify macula in fundus images by using structure label... AIM: To explore feasibility and practicability of macula localization independent of macular morphological features. METHODS: A novel method was proposed to identify macula in fundus images by using structure label transfer. Its main idea was to match a processed image with the candidate images with known structures, and then transfer the structure label representing the macular to the processed image as a result of macula localization. In this way, macula localization couldn't be influenced by lesion or other interference any more. RESULTS: The average success rate in four datasets was 98.18%. For accuracy, the average error distance in four datasets was 0.151 optic disc diameter (ODD). Even for severe lesion images, the proposed method can still maintain high success rate and high accuracy, e.g., 95.65% and 0.124 ODD in the case of STARE dataset, respectively, which indicated that the proposed method was highly robust and stable in the complicated situations. CONCLUSION: The proposed method can avoid the interference of lesion to macular morphological features in macula localization, and can locate macula with high accuracy and robustness, verifying its feasibility. 展开更多
关键词 fundus image optic disc MACULA structurelabel transfer
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Quasi-periodic Solutions of the General Nonlinear Beam Equations
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作者 GAO YI-XIAN 《Communications in Mathematical Research》 CSCD 2012年第1期51-64,共14页
In this paper, one-dimensional (1D) nonlinear beam equations of the form utt - uxx + uxxxx + mu = f (u) with Dirichlet boundary conditions are considered, where the nonlinearity f is an analytic, odd function an... In this paper, one-dimensional (1D) nonlinear beam equations of the form utt - uxx + uxxxx + mu = f (u) with Dirichlet boundary conditions are considered, where the nonlinearity f is an analytic, odd function and f(u) = O(u3). It is proved that for all m ∈ (0, M*] R (M* is a fixed large number), but a set of small Lebesgue measure, the above equations admit small-amplitude quasi-periodic solutions corresponding to finite dimensional invariant tori for an associated infinite dimensional dynamical system. The proof is based on an infinite dimensional KAM theory and a partial Birkhoff normal form technique. 展开更多
关键词 beam equation KAM theorem quasi-periodic solution partial Birkhoffnormal form
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Preprocessing of Spatial Query in Distributed GIS
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作者 Shengsheng Wang Dayou Liu Jie Liu 《通讯和计算机(中英文版)》 2005年第5期1-5,共5页
关键词 地理信息系统 数据处理 操作系统 信息共享
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NADARAYA-WATSON ESTIMATORS FOR REFLECTED STOCHASTIC PROCESSES
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作者 韩月才 张丁文 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期143-160,共18页
We study the Nadaraya-Watson estimators for the drift function of two-sided reflected stochastic differential equations.The estimates,based on either the continuously observed process or the discretely observed proces... We study the Nadaraya-Watson estimators for the drift function of two-sided reflected stochastic differential equations.The estimates,based on either the continuously observed process or the discretely observed process,are considered.Under certain conditions,we prove the strong consistency and the asymptotic normality of the two estimators.Our method is also suitable for one-sided reflected stochastic differential equations.Simulation results demonstrate that the performance of our estimator is superior to that of the estimator proposed by Cholaquidis et al.(Stat Sin,2021,31:29-51).Several real data sets of the currency exchange rate are used to illustrate our proposed methodology. 展开更多
关键词 reflected stochastic differential equation discretely observed process continuously observed process Nadaraya-Watson estimator asymptotic behavior
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A Novel Locomotion Rule Rmbedding Long Short-Term Memory Network with Attention for Human Locomotor Intent Classification Using Multi-Sensors Signals
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作者 Jiajie Shen Yan Wang Dongxu Zhang 《Computers, Materials & Continua》 SCIE EI 2024年第6期4349-4370,共22页
Locomotor intent classification has become a research hotspot due to its importance to the development of assistive robotics and wearable devices.Previous work have achieved impressive performance in classifying stead... Locomotor intent classification has become a research hotspot due to its importance to the development of assistive robotics and wearable devices.Previous work have achieved impressive performance in classifying steady locomotion states.However,it remains challenging for these methods to attain high accuracy when facing transitions between steady locomotion states.Due to the similarities between the information of the transitions and their adjacent steady states.Furthermore,most of these methods rely solely on data and overlook the objective laws between physical activities,resulting in lower accuracy,particularly when encountering complex locomotion modes such as transitions.To address the existing deficiencies,we propose the locomotion rule embedding long short-term memory(LSTM)network with Attention(LREAL)for human locomotor intent classification,with a particular focus on transitions,using data from fewer sensors(two inertial measurement units and four goniometers).The LREAL network consists of two levels:One responsible for distinguishing between steady states and transitions,and the other for the accurate identification of locomotor intent.Each classifier in these levels is composed of multiple-LSTM layers and an attention mechanism.To introduce real-world motion rules and apply constraints to the network,a prior knowledge was added to the network via a rule-modulating block.The method was tested on the ENABL3S dataset,which contains continuous locomotion date for seven steady and twelve transitions states.Experimental results showed that the LREAL network could recognize locomotor intents with an average accuracy of 99.03%and 96.52%for the steady and transitions states,respectively.It is worth noting that the LREAL network accuracy for transition-state recognition improved by 0.18%compared to other state-of-the-art network,while using data from fewer sensors. 展开更多
关键词 Lower-limb prosthetics deep neural networks motion classification
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Geometrical Characterizations of Non-Radiating Sources at Polyhedral and Conical Corners with Applications
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作者 Huaian Diao Yueran Geng +1 位作者 Hongyu Liu Qinghua Yu 《Communications in Mathematical Research》 CSCD 2023年第4期523-538,共16页
Considering the acoustic source scattering problems,when the sour-ce is non-radiating/invisible,we investigate the geometrical characterization for the underlying sources at polyhedral and conical corner.It is reveale... Considering the acoustic source scattering problems,when the sour-ce is non-radiating/invisible,we investigate the geometrical characterization for the underlying sources at polyhedral and conical corner.It is revealed that the non-radiating source with Holder continuous regularity must vanish at the corner.Using this kind of geometrical characterization of non-radiating sources,we establish local and global unique determination for a source with the polyhedral or corona shape support by a single far field measurement.Uniqueness by a single far field measurement constitutes of a long standing problem in inverse scattering problems. 展开更多
关键词 Non-radiating sources corner singularity VANISHING inverse scattering sin-gle far-field measurement
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Underwater Target Detection Based on Reinforcement Learning and Ant Colony Optimization 被引量:1
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作者 WANG Xinhua ZHU Yungang +1 位作者 LI Dayu ZHANG Guang 《Journal of Ocean University of China》 SCIE CAS CSCD 2022年第2期323-330,共8页
Underwater optical imaging produces images with high resolution and abundant information and hence has outstanding advantages in short-distance underwater target detection.However,low-light and high-noise scenarios po... Underwater optical imaging produces images with high resolution and abundant information and hence has outstanding advantages in short-distance underwater target detection.However,low-light and high-noise scenarios pose great challenges in un-derwater image and video analyses.To improve the accuracy and anti-noise performance of underwater target image edge detection,an underwater target edge detection method based on ant colony optimization and reinforcement learning is proposed in this paper.First,the reinforcement learning concept is integrated into artificial ants’movements,and a variable radius sensing strategy is pro-posed to calculate the transition probability of each pixel.These methods aim to avoid undetection and misdetection of some pixels in image edges.Second,a double-population ant colony strategy is proposed,where the search process takes into account global search and local search abilities.Experimental results show that the algorithm can effectively extract the contour information of underwater targets and keep the image texture well and also has ideal anti-interference performance. 展开更多
关键词 ant colony optimization reinforcement learning underwater target edge detection
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Interpolation and approximation for data living on manifold surfaces 被引量:1
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作者 HU Jianping LIU Xiuping +1 位作者 WANG Xiaochao XIE Qi 《Computer Aided Drafting,Design and Manufacturing》 2012年第4期16-20,共5页
Meshed surfaces are ubiquitous in digital geometry processing and computer graphics. The set of attributes associated with each vertex such as the vertex locations, curvature, temperature, pressure or saliency, can be... Meshed surfaces are ubiquitous in digital geometry processing and computer graphics. The set of attributes associated with each vertex such as the vertex locations, curvature, temperature, pressure or saliency, can be recognized as data living on mani- fold surfaces. So interpolation and approximation for these data are of general interest. This paper presents two approaches for mani- fold data interpolation and approximation through the properties of Laplace-Beltrami operator (Laplace operator defined on a mani- fold surface). The first one is to use Laplace operator minimizing the membrane energy of a scalar function defined on a manifold. The second one is to use bi-Laplace operator minimizing the thin plate energy of a scalar function defined on a manifold. These two approaches can process data living on high genus meshed surfaces. The approach based on Laplace operator is more suitable for manifold data approximation and can be applied manifold data smoothing, while the one based on bi-Laplace operator is more suit- able for manifold data interpolation and can be applied image extremal envelope computation. All the application examples demon- strate that our procedures are robust and efficient. 展开更多
关键词 manifold data interpolation and approximation Laplace operator bi-Laplace operator manifold data smoothing imageextremal envelope computation
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KAM Type-Theorem for Lower Dimensional Tori in Random Hamiltonian Systems
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作者 LI YONG XU LU 《Communications in Mathematical Research》 CSCD 2011年第1期81-96,共16页
In this paper, we study the persistence of lower dimensional tori for random Hamiltonian systems, which shows that majority of the unperturbed tori persist as Cantor fragments of lower dimensional ones under small per... In this paper, we study the persistence of lower dimensional tori for random Hamiltonian systems, which shows that majority of the unperturbed tori persist as Cantor fragments of lower dimensional ones under small perturbation. Using this result, we can describe the stability of the non-autonomous dynamic systems. 展开更多
关键词 random Hamiltonian system KAM type theorem Cantor fragment of invariant tori
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An embedded vertical‐federated feature selection algorithm based on particle swarm optimisation 被引量:1
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作者 Yong Zhang Ying Hu +4 位作者 Xiaozhi Gao Dunwei Gong Yinan Guo Kaizhou Gao Wanqiu Zhang 《CAAI Transactions on Intelligence Technology》 SCIE EI 2023年第3期734-754,共21页
In real life,a large amount of data describing the same learning task may be stored in different institutions(called participants),and these data cannot be shared among par-ticipants due to privacy protection.The case... In real life,a large amount of data describing the same learning task may be stored in different institutions(called participants),and these data cannot be shared among par-ticipants due to privacy protection.The case that different attributes/features of the same instance are stored in different institutions is called vertically distributed data.The pur-pose of vertical‐federated feature selection(FS)is to reduce the feature dimension of vertical distributed data jointly without sharing local original data so that the feature subset obtained has the same or better performance as the original feature set.To solve this problem,in the paper,an embedded vertical‐federated FS algorithm based on particle swarm optimisation(PSO‐EVFFS)is proposed by incorporating evolutionary FS into the SecureBoost framework for the first time.By optimising both hyper‐parameters of the XGBoost model and feature subsets,PSO‐EVFFS can obtain a feature subset,which makes the XGBoost model more accurate.At the same time,since different participants only share insensitive parameters such as model loss function,PSO‐EVFFS can effec-tively ensure the privacy of participants'data.Moreover,an ensemble ranking strategy of feature importance based on the XGBoost tree model is developed to effectively remove irrelevant features on each participant.Finally,the proposed algorithm is applied to 10 test datasets and compared with three typical vertical‐federated learning frameworks and two variants of the proposed algorithm with different initialisation strategies.Experi-mental results show that the proposed algorithm can significantly improve the classifi-cation performance of selected feature subsets while fully protecting the data privacy of all participants. 展开更多
关键词 Evolutionary optimization feature selection privacy protection vertical‐federated learning
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Visual Analysis of the National Characteristics of the COVID-19 Vaccine Based on Knowledge Graph
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作者 Yong Feng Ning Zhang +2 位作者 Hongyan Xu Rongbing Wang Yonggang Zhang 《国际计算机前沿大会会议论文集》 2022年第1期262-272,共11页
The aim is to construct a country-dimension knowledge graph of COVID-19 vaccines from the information of COVID-19 vaccines and to analyze the leading countries of vaccine R&D by combining the advantages of easy op... The aim is to construct a country-dimension knowledge graph of COVID-19 vaccines from the information of COVID-19 vaccines and to analyze the leading countries of vaccine R&D by combining the advantages of easy operation and intuitive feeling of knowledge graph visualization,to provide a reference for Chinese vaccine R&D departments and international cooperation.In this paper,through data collection,based on entity extraction and relationship construction,a knowledge graph of country dimensions was established by specifying the central vaccine R&D countries and vaccine distribution,and multidimensional microdata such as word frequency and betweenness centrality were combined to analyze the national characteristics of the COVID-19 vaccine.The analysis of the knowledge graph of the country dimension of the COVID-19 vaccine shows that countries with robust technology and economies,such as the US and China,choose to develop vaccine distribution independently,countries with advanced economies,such as Saudi Arabia,decide to purchase vaccine distribution,and less developed countries,such as South Africa and Latin America,need international aid for vaccines or purchase low-cost vaccines.This paper constructs the correlation between nodes and nodes of the COVID-19 vaccine with the help of a knowledge graph,systematically and comprehensively reveals the research mainstay and distribution model of the COVID-19 vaccine from the national level,and provides rationalized suggestions for international cooperation in vaccine R&D in China. 展开更多
关键词 DIMENSION DIMENSIONS RATIONAL
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