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30th International Ocean and Polar engineering Conference, ISOPE 2020

作者： Yan, Mingwei Ma, Xin Li, Yibin Bai, Wei School of Control Science and Engineering Shandong University JinanShandong Province China Centre for Mathematical Modelling and Flow Analysis School of Computing Mathematics and Digital Technology Manchester Metropolitan University Manchester United Kingdom

ISBN: (纸本)9781880653845

The purpose of present paper is to evaluate how the forces and moments acting on the cylinder or the cuboid payload change with the relative postures between the wave incident direction and the offshore crane payload, and to develop a PID controller for the payload to hold its posture in the presence of external wave forces. Aiming at this purpose, numerical results of regular wave interaction with a vertically suspending cylinder are presented first to validate the NWT model, and then a series of simulation experiments which offer results of the forces and the moments exerted by the regular waves on one fixed suspending cylinder and cuboid payload with different postures. With some certain posture, the suspending cylinder and cuboid payload suffer the minimal forces and moments. After that, the PID controller is raised and applied on a free heave decay cylinder for validation. Lastly, the same PID controller is applied on the cuboid payload subjected to wave forces. The results show the controller works well in keeping the payload with a certain posture. All of the present works provide the fundamentals for further research on safe control of offshore lifting or lowering. © 2020 by the International Society of Offshore and Polar Engineers (ISOPE).

关键词： controllers

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Research on Vehicle Forward Pedestrian Recognition Based on Multi-line LIDAR

Research on Vehicle Forward Pedestrian Recognition Based on ...

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Chinese Intelligent Systems Conference, CISC 2019

作者： Guo, Chenyang Yu, Guizhen Zhang, Li Niu, Huan Zhou, Bin Wang, Zhangyu Li, Da School of Transportation Science and Engineering Beijing Advanced Innovation Center for Big Data and Brain Computing Beijing Key Laboratory for Cooperative Vehicle Infrastructure Systems and Safety Control Beihang University Beijing100191 China

ISBN: (纸本)9789813296978

Pedestrians are one of the most important elements in traffic scenes. In autopilot system, pedestrians need to be accurately detected. We found the latest research that 3D light detection and ranging (LIDAR) sensors can provide more accurate pedestrian location information. In this paper, the AdaBoost algorithm is used to improve the accuracy of the support vector machine (SVM) and high-accuracy pedestrian detection based on real-time 3D point cloud data. The first step is to process 3D points to 2D grid, followed by using k-means clustering algorithm to extract candidate points of the pedestrian. Next, nine features are chosen to train the SVM, the AdaBoost iterative process is used to reduce the further error rate to meet the classification requirements. This method has achieved significant progress in our experiment, the average classification accuracy has been improved to 92.4% per scan. © 2020, Springer Nature Singapore Pte Ltd.

关键词： Adaptive boosting

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AutoFlow: Hotspot-aware, dynamic load balancing for distributed stream processing

arXiv

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arXiv 2021年

作者： Lu, Pengqi Yuan, Liang Zhang, Yunquan Cao, Hang Li, Kun State Key Laboratory of Computer Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing China School of Computer and Control Engineering University of Chinese Academy of Sciences Beijing China

Stream applications are widely deployed on the cloud. While modern distributed streaming systems like Flink and Spark Streaming can schedule and execute them efficiently, streaming dataflows are often dynamically changing, which may cause computation imbalance and backpressure. We introduce AutoFlow, an automatic, hotspot-aware dynamic load balance system for streaming dataflows. It incorporates a centralized scheduler which monitors the load balance in the entire dataflow dynamically and implements state migrations correspondingly. The scheduler achieves these two tasks using a simple asynchronous distributed control message mechanism and a hotspot-diminishing algorithm. The timing mechanism supports implicit barriers and a highly efficient state-migration without global barriers or pauses to operators. It also supports a time-window based load-balance measurement and feeds them to the hotspot-diminishing algorithm without user interference. We implemented AutoFlow on top of Ray, an actor-based distributed execution framework. Our evaluation based on various streaming benchmark dataset shows that AutoFlow achieves good loadbalance and incurs a low latency overhead in highly data-skew workload. © 2021, CC BY.

关键词： Distributed parameter control systems

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Faster Randomized Dynamical Decoupling

arXiv

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arXiv 2024年

作者： Yi, Changhao Kim, Leeseok Marvian, Milad Center for Quantum Information and Control University of New Mexico NM87131 United States Department of Physics and Astronomy University of New Mexico NM87131 United States State Key Laboratory of Surface Physics Department of Physics Fudan University Shanghai200433 China Institute for Nanoelectronic Devices and Quantum Computing Fudan University Shanghai200433 China Department of Electrical and Computer Engineering University of New Mexico NM87131 United States

We present a randomized dynamical decoupling (DD) protocol that can substantially improve the performance of any given deterministic DD, by using no more than two additional pulses. Our construction is implemented by probabilistically applying sequences of pulses, which, when combined, effectively eliminate the error terms that scale linearly with the system-environment coupling strength. As a result, we show that a randomized protocol using a few pulses can outperform deterministic DD protocols that require considerably more pulses. Furthermore, we prove that the randomized protocol provides an improvement compared to deterministic DD sequences that aim to reduce the error in the system’s Hilbert space, such as Uhrig DD, which had been previously regarded to be optimal. To rigorously evaluate the performance, we introduce new analytical methods suitable for analyzing higher-order DD protocols that might be of independent interest. We also present numerical simulations confirming the significant advantage of using randomized protocols compared to widely used deterministic protocols. Copyright © 2024, The Authors. All rights reserved.

关键词： Hilbert spaces

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Size-invariance matters: rethinking metrics and losses for imbalanced multi-object salient object detection 24

Size-invariance matters: rethinking metrics and losses for i...

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Proceedings of the 41st International Conference on Machine Learning

作者： Feiran Li Qianqian Xu Shilong Bao Zhiyong Yang Runmin Cong Xiaochun Cao Qingming Huang Institute of Information Engineering Chinese Academy of Sciences Beijing China and School of Cyber Security University of Chinese Academy of Sciences Beijing China Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing China School of Computer Science and Technology University of Chinese Academy of Sciences Beijing China Institute of Information Science Beijing Jiaotong University Beijing China and School of Control Science and Engineering Shandong University Jinan China and Key Laboratory of Machine Intelligence and System Control Ministry of Education Jinan China School of Cyber Science and Tech. Shenzhen Campus Sun Yat-sen University School of Computer Science and Technology University of Chinese Academy of Sciences Beijing China and Key Laboratory of Intelligent Information Processing Institute of Computing Technology Chinese Academy of Sciences Beijing China and Key Laboratory of Big Data Mining and Knowledge Management Chinese Academy of Sciences Beijing China

This paper explores the size-invariance of evaluation metrics in Salient Object Detection (SOD), especially when multiple targets of diverse sizes co-exist in the same image. We observe that current metrics are size-sensitive, where larger objects are focused, and smaller ones tend to be ignored. We argue that the evaluation should be size-invariant because bias based on size is unjustified without additional semantic information. In pursuit of this, we propose a generic approach that evaluates each salient object separately and then combines the results, effectively alleviating the imbalance. We further develop an optimization framework tailored to this goal, achieving considerable improvements in detecting objects of different sizes. Theoretically, we provide evidence supporting the validity of our new metrics and present the generalization analysis of SOD. Extensive experiments demonstrate the effectiveness of our method. The code is available at https://***/Ferry-Li/SI-SOD.

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A Vision-Based Method for Vehicle Forward Collision Warning

A Vision-Based Method for Vehicle Forward Collision Warning

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Chinese Intelligent Systems Conference, CISC 2019

作者： Zhang, Yanfei Wang, Zhangyu Zhou, Bin Yu, Guizhen Hu, Chaowei Zhang, Li School of Transportation Science and Engineering Beijing Advanced Innovation Center for Big Data and Brain Computing Beijing Key Laboratory for Cooperative Vehicle Infrastructure Systems and Safety Control Beihang University Beijing100191 China

ISBN: (纸本)9789813296978

Forward Collision Warning (FCW) system can automatically measure the distance between obstacles and provide early warning, which can effectively provide safety guarantee for vehicle travel and reduce the probability of traffic accidents. The vision-based approaches are always popular because vision sensors have the characteristics of low cost and rich image information. In this paper, a vision-based forward collision warning method is proposed. The method contains three main stages: (1) detect obstacle based on multi-feature fusion using convolution neural networks (CNN), (2) estimate the relative distance, relative velocity from vehicles and collision time, (3) design obstacles hazard level discrimination strategy for different road scenarios. The algorithm is tested on our own dataset and the experiment results showed that the method has good feasibility and robustness. © 2020, Springer Nature Singapore Pte Ltd.

关键词： Hazards

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H ∞ Asynchronous control for Discrete-Time Semi-Markov Jump Systems

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IFAC-PapersOnLine 2022年第3期55卷 143-148页

作者： Liqiang Jin Yanyan Yin Yanqing Liu Kok Lay Teo Fei Liu National Key Laboratory of Advanced Process Control for Light Industry (Ministry of Education) Institute of Automation Jiangnan University Wuxi 214122 China School of Electrical Engineering Computing and Mathematical Sciences Curtin University Perth Western Australia 6102 Australia School of Mathematical Sciences Sunway University Kuala Lumpur 47500 Malaysia Tianjin University of Finance and Economics Tianjin China

This paper investigates the problem of H ∞ asynchronous control for discrete-time semi-Markov jump systems. In practice, it is difficult to ensure that controller modes and system modes are updated synchronously. Therefore, a hidden semi-Markov model is introduced to characterize such an asynchronous phenomenon between system modes and controller modes. Meanwhile, the switching signal of the controller is generated by a given conditional probability related to the system mode. Based on the mode-dependent and elapsed-time-dependent Lyapunov function, together with the semi-Markov kernel (SMK) method, sufficient conditions constructed by linear matrix inequalities (LMIs) are derived to ensure the existence of an asynchronous controller such that the resulting system is σ-error mean square stable and satisfies an H ∞ performance index. Finally, a numerical example is given to illustrate the effectiveness and feasibility of the method proposed.

关键词： Asynchronous control semi-Markov jump systems hidden semi-Markov model semi-Markov kernel (SMK) σ-error mean square stable

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Adjusted and controllability Properties of Memristor Rucklidge System

Adjusted and Controllability Properties of Memristor Rucklid...

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Memristive computing and Applications (ICMCA), IEEE International Conference on

作者： Hongyan Zang Lili Huang Shourong Zhang Annie Anak Joseph Haiyan Fu Tengfei Lei Collaborative Innovation Center of Memristive Computing Application Qilu Institute of Technology Jinan P. R. China Faculty of Engineering Universiti Malaysia Sarawak Kota Samarahan Sarawak Malaysia College of Intelligent Manufacturing and Control Engineering Qilu Institute of Technology Jinan P. R. China Shandong Vanform High Energy Physics Technology Co. Ltd. Jinan P. R. China Department of Electrical and Electronics Universiti Malaysia Sarawak Kota Samarahan Sarawak Malaysia College of Computer and Information Engineering Qilu Institute of Technology Jinan P. R. China Collaborative Innovation Center of Memristive Computing Application(CICMCA) Qilu Institute of Technology Jinan P. R. China

There are many models of memristors, but there are no reports on exponential memristors. In this paper, a three- dimension memristor Rucklidge system with exponential memristor is proposed by introducing exponential function and constructing exponential memristor. The dynamic behavior of the system is analyzed by means of Lyapunov exponent and bifurcation diagram. The complex attractor coexistence and amplitude modulation characteristics of the system are found. The internal variable of memristor is introduced into the second two-dimensional equation as a feedback term, and a conditional symmetric system is constructed for the three-dimensional memristor system, which can realize the polarity control of output signal. By discussing the dynamic characteristics of exponential memristor chaotic system and the control mechanism of amplitude modulation, bias and conditional symmetry, the complex dynamic characteristics of exponential function memristor are revealed, which lays a foundation for its application in the field of secure communication.

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Fair Equilibria in Sponsored Search Auctions: The Advertisers’ Perspective

arXiv

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arXiv 2021年

作者： Birmpas, Georgios Celli, Andrea Colini-Baldeschi, Riccardo Leonardi, Stefano Department of Computer Control and Management Engineering Sapienza University Rome Italy Department of Computing Sciences Bocconi University Milan Italy Core Data Science Meta London United Kingdom

In this work we introduce a new class of mechanisms composed of a traditional Generalized Second Price (GSP) auction and a fair division scheme, in order to achieve some desired level of fairness between groups of Bayesian strategic advertisers. We propose two mechanisms, β-Fair GSP and GSP-EFX, that compose GSP with, respectively, an envy-free up to one item, and an envy-free up to any item fair division scheme. The payments of GSP are adjusted in order to compensate advertisers that suffer a loss of efficiency due the fair division stage. We investigate the strategic learning implications of the deployment of sponsored search auction mechanisms that obey to such fairness criteria. We prove that, for both mechanisms, if bidders play so as to minimize their external regret they are guaranteed to reach an equilibrium with good social welfare. We also prove that the mechanisms are budget balanced, so that the payments charged by the traditional GSP mechanism are a good proxy of the total compensation offered to the advertisers. Finally, we evaluate the quality of the allocations through experiments on real-world data. Copyright © 2021, The Authors. All rights reserved.

关键词： Machine learning

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Machine learning framework for computing the most probable paths of stochastic dynamical systems

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Physical Review E 2021年第1期103卷 012124-012124页

作者： Yang Li Jinqiao Duan Xianbin Liu State Key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics 29 Yudao Street Nanjing 210016 China Department of Applied Mathematics College of Computing Illinois Institute of Technology Chicago Illinois 60616 USA

The emergence of transition phenomena between metastable states induced by noise plays a fundamental role in a broad range of nonlinear systems. The computation of the most probable paths is a key issue to understanding the mechanism of transition behaviors. The shooting method is a common technique for this purpose to solve the Euler-Lagrange equation for the associated action functional, while losing its efficacy in high-dimensional systems. In the present work, we develop a machine learning framework to compute the most probable paths in the sense of Onsager-Machlup action functional theory. Specifically, we reformulate the boundary value problem of a Hamiltonian system and design a neural network to remedy the shortcomings of the shooting method. The successful applications of our algorithms to several prototypical examples demonstrate its efficacy and accuracy for stochastic systems with both (Gaussian) Brownian noise and (non-Gaussian) Lévy noise. This approach is effective in exploring the internal mechanisms of rare events triggered by random fluctuations in various scientific fields.

关键词： Diffusion Fluctuations & noise Neuronal networks

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