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Control of fractional chaotic and hyperchaotic systems based on a fractional order controller

Chinese Physics B 2014年第8期23卷 274-284页

作者： Li Tian-Zeng Wang Yu Luo Mao-Kang College of Mathematics Sichuan University Chengdu 610065 China Sichuan Province University Key Laboratory of Bridge Non-destruction Detecting and Engineering Computing School of Science Sichuan University of Science and Engineering Zigong 643000 China

We present a new fractional-order controller based on the Lyapunov stability theory and propose a control method which can control fractional chaotic and hyperchaotic systems whether systems are commensurate or incommensurate. The proposed control method is universal, simple, and theoretically rigorous. Numerical simulations are given for several fractional chaotic and hyperchaotic systems to verify the effectiveness and the universality of the proposed control method.

关键词： fractional-order chaotic system chaos control fractional-order controller hyperchaos

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Simulation of Manipulator Path Planning Based on Improved RRT∗ Algorithm 5

Simulation of Manipulator Path Planning Based on Improved RR...

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5th International Conference on Pattern Recognition and Artificial Intelligence, PRAI 2022

作者： Liu, XueShen Cao, Lijia Sichuan University of Science & Engineering Artificial Intelligence Key Laboratory of Sichuan Province Sichuan Prov. Univ. Key Laboratory of Bridge Non-Destruction Detecting and Engineering Computing Yibin China

ISBN: (数字)9781665499163

ISBN: (纸本)9781665499163

The problem of obstacle avoidance path planning of 6-axis manipulator is studied. After analyzing the disadvantages of large randomness and low algorithm efficiency of RRT*, an improved RRT∗ algorithm is proposed, which can quickly search the shortest expected path that can effectively avoid obstacles. Firstly, the path pruning process of RRT∗ is improved to improve the degree of path optimization, and then the global sampling space is reduced, so that the random tree can quickly expand to the target point. The algorithm is verified on the MATLAB simulation platform. The results show that the average time of path search and the number of expansion nodes of the improved RRT∗ algorithm are greatly reduced, the path length is also better than the traditional RRT*, and can be well applied to the path planning of manipulator. © 2022 IEEE.

关键词： Motion planning

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A homomorphic universal re-encryptor for identity-based encryption

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International Journal of Network Security 2017年第1期19卷 11-19页

作者： Liu, Liang Ye, Jun Xidian University No. 2 South Taibai Road Yanta District Xi'an Shaanxi710071 China Artificial Intelligence Key Laboratory of Sichuan Province Sichuan University of Science and Engineering No. 180 School Street Huixing Road Sichuan643000 China Sichuan Province University Key Laboratory of Bridge Non-destruction Detecting and Engineering Computing No. 180 School Street Huixing Road Sichuan643000 China

Re-encryption (or proxy re-encryption) is a very useful cryptographic primitive which is able to transform a ciphertext under one public key into a new ciphertext encrypting the same message but under another different public key. It plays an important role in modern secure communication and information exchange via various kinds of network infrastructure. In addition to traditional public-key encryption scheme, re-encryption can also come into force in other cryptosystems like Identity-Based Encryption (IBE) and more advanced Functional Encryption (FE), making the enhanced schemes more powerful as well as easy-to-use. In this work, we have proposed a novel identity-based proxy re-encryption (IBPRE) scheme which to the maximum extent reduces the workloads in the user side by delivering the re-encryption key (RK) generation work to the proxy server. Besides, it is likewise able to prevent possible bottlenecks for the users, like re-encryption key management.

关键词： Public key cryptography

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Image reconstruction of concrete based on Filtered Backprojection method using ultrasonic time of flight data

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Computer Modelling and New Technologies 2014年第6期18卷 72-78页

作者： Fan, Honghui Zhu, Hongjin Han, Qingbang School of Computer Engineering Jiangsu University of Technology Changzhou Jiangsu China Sichuan Province Key Laboratory of Bridge non-destructive testing and engineering computing Zigong Sichuan China Key Laboratory of Cloud Computing Intelligent Information Processing of Changzhou City Changzhou Jiangsu China College of IOT Engineering Hohai University Jiangsu China

This research aims to recognize the defect of concrete materials using an ultrasonic computed tomography imaging technique. Filtered Backprojection method was used to reconstruct concrete images in this paper. Ultrasonic time of flight data was measured to reconstruct computer tomography images. 306 data paths were obtained in total by manual scanning for one computer tomography image. We examined the effect of the interpolation data as the density of time of flight data has a considerable effect on image quality. The feasibility of concrete reconstruction system and time of flight data interpolation were examined in detail using numerical and concrete phantoms.

关键词： Interpolation

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A Relaxed Greedy Block Kaczmarz Method for Solving Large Consistent Linear Systems

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Journal of Applied Mathematics and Physics 2021年第12期9卷 3032-3044页

作者： Yimou Liao Feng Yin Guangxin Huang College of Mathematics and Statistics Sichuan University of Science & Engineering Zigong China Sichuan Province University Key Laboratory of Bridge Non-destruction Detecting and Engineering Computing Zigong China College of Mathematics and Physics Chengdu University of Technology Chengdu China

Many problems in science and engineering require solving large consistent linear systems. This paper presents a relaxed greedy block Kaczmarz method (RGBK) and an accelerated greedy block Kaczmarz method (AGBK) for solving large-size consistent linear systems. The RGBK algorithm extends the greedy block Kaczmarz algorithm (GBK) presented by Niu and Zheng in [1] by introducing a relaxation parameter to the iteration formulation of GBK, and the AGBK algorithm uses different iterative update rules to minimize the running time. The convergence of the RGBK is proved and a method to determine an optimal parameter is provided. Several examples are presented to show the effectiveness of the proposed methods for overdetermined and underdetermined consistent linear systems with dense and sparse coefficient matrix.

关键词： Linear Consistent Systems Convergence Properties Relaxed Greedy Block Kaczmarz

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A Geometric Gaussian Kaczmarz Method for Large Scaled Consistent Linear Equations

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Journal of Applied Mathematics and Physics 2021年第11期9卷 2954-2965页

作者： Li Wen Feng Yin Yimou Liao Guangxin Huang College of Mathematics and Statistics Sichuan University of Science and Engineering Zigong China Sichuan Province University Key Laboratory of Bridge Non-Destruction Detecting and Engineering Computing Zigong China College of Mathematics and Physics Chengdu University of Technology Chengdu China

This paper presents a geometric Gaussian Kaczmarz (GGK) method for solving the large-scaled consistent linear systems of equation. The GGK method improves the geometric probability randomized Kaczmarz method in [1] by introducing a new block set strategy and the iteration process. The GGK is proved to be of linear convergence. Several numerical examples show the efficiency and effectiveness of the GGK method.

关键词： Gaussian Kaczmarz Convergence Rate Linear Systems Consistent

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An Improved Lightweight Small Target Detection Algorithm for Air-to-Ground Image

SSRN

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SSRN 2022年

作者： Cao, Lijia Song, Pinde Wang, Yongchao Geng, Chuang Peng, Baoyu Sichuan University of Science & Engineering Yibin644000 China Technical University of Munich Munich80333 Germany Artificial Intelligence Key Laboratory of Sichuan Province Yibin644000 China Sichuan Province University Key Laboratory of Bridge Non-destruction Detecting and Engineering Computing Yibin644000 China

Air-to-Ground target detection algorithm is of great significance to achieve military countermeasures and disaster search and rescue. The state-of-the-art object detection algorithm, YOLOv5, has been widely used to detect UAV image. However, it suffers some challenges, such as high FLOPs, redundant parameters, longer inference time and poor performance of small target detection. To address these issues, an improved lightweight object detection method is proposed for UAVs images. In the presented method, MobileNetv3 is introduced into the YOLOv5 backbone network to reduce the parameters and float-point operations(FLOPs). An extra prediction head is introduced into the shallow layer of the neck to improve the algorithm's ability of small targets. Besides, we design two kinds of neck structures with different parameter scales to meet the requirements of different embedded devices. Finally, the Hardswish activation function is used in the neck network to accelerate the inference speed of the improved algorithm. To validate the performance of the proposed improved algorithm, we tested our algorithm in VisDrone-Det2019 dataset. The results show that, compared with YOLOv5l and YOLOv5x, the number of parameters of MEN-YOLOv5-L decreased by 87.4% and 93.3%, the FLOPs decreased by 47.2% and 72.1%, and mAP@0.5 increased by 7.3% and 5.9%, respectively. MEN-YOLOv5-S has 51.4% and 38.4% lower number of parameters and FLOPs, respectively, and 2.5% higher mAP@0.5 than YOLOv5s. © 2022, The Authors. All rights reserved.

关键词： Image enhancement

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An Improved Lightweight Small Target Detection Algorithm for Air-to-Ground Images

SSRN

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SSRN 2022年

A lightweight target detection algorithm, MobileNetv3 extended neck YOLOv5 (MEN-YOLOv5) is proposed in this paper to simplify the complex structure of the YOLOv5 target detection network, reduce the number of model parameters, and improve detection accuracy of small targets. Firstly, to reduce the number of parameters, the backbone network YOLOv5 is re-constructed using the MobileNetv3 depthwise separable convolution. Secondly, in accordance with the characteristics of the air-to-ground detected targets and the YOLOv5 algorithm, the layers are extended to the shallow-layer on the basis of the Neck network structure and more shallow feature information are fused, which makes the developed algorithm have a smaller receptive field and improves accuracy of detection of small targets. Finally, channel parameters are re-designed and the Neck network structure is rebuilt to avoid the dramatic increase in the number of parameters. As a result, the number of parameters in the entire network structure are compressed to the maximum extent possible to produce lightweight target detection models. The effectiveness of the proposed algorithm is verified by experiments with the VisDrone-DET2019 dataset and the experimental results show that, compared with YOLOv5l and YOLOv5x, the numbers of parameters of MEN-YOLOv5-L reduce by 86.8% and 92.98%, and floating point operations (FLOPs) decrease by 46.18% and 71.58%, and mAP50 values increase by 7.18% and 5.78%, respectively. MEN-YOLOv5-S has 52.9% and 30.8% lower number of parameters and FLOPs, respectively, and 2.5% higher mAP50 than YOLOv5s. © 2022, The Authors. All rights reserved.

关键词： Signal detection

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Some Sufficient Conditions Under Which a non-Autonomous Discrete System or Semi-Flow is Sensitive

SSRN

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SSRN 2022年

作者： Li, Risong Wang, Hongqing Lu, Tianxiu Li, YongJiang Quan, Weizhen School of Mathematics and Computer Science Guangdong Ocean University Zhanjiang524025 China College of Mathematics and Statistics Sichuan University of Science and Engineering Zigong Sichuan 643000 China Bridge Non-destruction Detecting and Engineering Computing Key Laboratory of Sichuan Province Zigong Sichuan 643000 China Artificial Intelligence Key Laboratory of Sichuan Province Key Laboratory of Higher Education of Sichuan Province for Enterprise Informationalization and Internet of Things Zigong Sichuan 643000 China Department of Mathematics Zhanjiang Preschool Education College Zhanjiang524037 China

In this paper we are concerned withsensitivity for non-autonomous discrete systems and semi-flows. Somesufficient conditions of sensitivity for non-autonomous discretesystems and semi-flows are established, where it is not requiredthat maps and semi-flows are continuous or measure-preserving, andthat spaces are compact. In particular, it is shown that if anon-autonomous discrete system (F1,∞, G) (resp. a semi-flow F) on a nontrivial metric space (G,p) satisfies one of thefollowing two conditions:(1) d(NF1,∞(V,V)) + d(NF1,∞(U,V)) > 1 (resp. d(NF(V,V) + d(NF(U,V)) > 1) for any open sets U,V ⊂ G with U, V ≠ ∅;(2) [[EQUATION]] for any open sets U,V ⊂ G with U, V ≠ ∅,then it is ergodically sensitive, which means that it is sensitive. Our results improve and extend the exiting results. © 2022, The Authors. All rights reserved.

关键词： Topology

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