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Robust symbol-level precoding and passive beamforming for IRS-aided communications

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arXiv 2021年

作者： Zhang, Guangyang Shen, Chao Ai, Bo Zhong, Zhangdui Beijing Jiaotong University State Key Laboratory of Rail Traffic Control and Safety Beijing100044 China Frontiers Science Center for Smart High-speed Railway System Beijing100044 China Beijing Engineering Research Center of High-speed Railway Broadband Mobile Communications 100044 China Key Laboratory of Railway Industry of Broadband Mobile Information Communications Beijing100044 China

This paper investigates a joint beamforming design in a multiuser multiple-input single-output (MISO) communication network aided with an intelligent reflecting surface (IRS) panel. The symbol-level precoding (SLP) is adopted to enhance the system performance by exploiting the multiuser interference (MUI) with consideration of bounded channel uncertainty. The joint beamforming design is formulated into a nonconvex worst-case robust programming to minimize the transmit power subject to single-to-noise ratio (SNR) requirements. To address the challenges due to the constant modulus and the coupling of the beamformers, we first study the single-user case. Specifically, we propose and compare two algorithms based on the semidefinite relaxation (SDR) and alternating optimization (AO) methods, respectively. It turns out that the AO-based algorithm has much lower computational complexity but with almost the same power to the SDR-based algorithm. Then, we apply the AO technique to the multiuser case and thereby develop an algorithm based on the proximal gradient descent (PGD) method. The algorithm can be generalized to the case of finite-resolution IRS and the scenario with direct links from the transmitter to the users. Numerical results show that the SLP can significantly improve the system performance. Meanwhile, 3-bit phase shifters can achieve near-optimal power performance. © 2021, CC BY.

关键词： Gradient methods

A 4-Channel Ultrafast Wavelength-Swept REC-DFB Laser Array for Fiber Bragg Grating Interrogation

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A 4-Channel Ultrafast Wavelength-Swept REC-DFB Laser Array f...

Asia Communications and Photonics Conference and Exhibition (ACP)

作者： Lingxin Meng Pan Dai Qilu Ban Kaichuan Xu Jiacheng Wang Zhen Li Feng Wang Jie Zeng Shaobo Li Xiang Ma Xiangfei Chen Key Laboratory of Intelligent Optical Sensing and Manipulation of the Ministry of Education & Engineering National Laboratory of Solid State Microstructures Research Center of Precision Photonics Integration and System Application of the Ministry of Education College of Engineering and Applied Sciences Nanjing University Nanjing China State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and Astronautics Nanjing China Optical Communication Research and Development Center the 54th Research Institute of China Electronics Technology Group Corporation Shijiazhuang China

We present a four-channel ultrafast wavelength-swept distributed feedback (DFB) semiconductor laser array based on the reconstruction-equivalent-chirp (REC) technique using instantaneous injection current modulation. With the aid of our designed laser driving circuit system consists of the microcontroller unit (MCU), field-programmable gate array (FPGA) and negative metal-oxide-semiconductor field effect transistors (n-MOSFETs), the precise pulse driving current for the 4-channel wavelength-swept REC-DFB laser array can be generated and a fast tuning of 16.424 nm within 10 μs is achieved. To further investigate the tuning performance of the proposed wavelength-swept laser source, we then applied it to the fiber Bragg grating (FBG) interrogation system and four FBG temperature sensor arrays were successfully demodulated. The development of high-efficient optical sensing systems heavily relies on the significance of the ultrafast wavelength-swept laser source, which has the potential to greatly enhance FBG interrogator performance in the future.

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New algorithm based on the distribution of the normalized equivalent instantaneous inductance for the discrimination of inrush

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Zhongguo Dianji Gongcheng Xuebao/Proceedings of the Chinese Society of Electrical engineering 2005年第23期25卷 47-53页

作者： Zheng, Tao Liu, Wan-Shun Zhuang, Heng-Jian Li, Xiao-Bo Laboratory of Power System Protection and Dynamic Security Monitoring and Control North China Electric Power University Beijing 102206 China SP Longyuan Environment Engineering Beijing 100761 China

Oriented to wye-delta connected three phase transformer, a new configuration of current transformer (CT) in transformer differential protection is proposed. In this configuration, only one single phase CT connected in any phase of the delta side is more needed than the traditional scheme. Worked with line currents measured by other current transformers connected in both sides of the transformer, any phase current in the delta side can be calculated based on the Kirchhoff's Current Law. This new scheme ensures the accurate calculation of the equivalent instantaneous inductance, which is immune to the loop current existed in the delta side of transformer, as well as no dead zone in transformer differential protection. A new algorithm based on the distribution of the normalized equivalent instantaneous inductance for the discrimination between inrush current and fault current is proposed. The normalization of equivalent instantaneous inductance makes the setting-value have little relation with the parameter of transformers, which has more universal meaning in the determination of setting values. Utilizing the distributive characteristic of the normalized equivalent instantaneous inductance, the variety of the normalized equivalent instantaneous inductance is effectively revealed. At last, experiment data obtained from HYBRISIM (Hybrid Simulator) validates the reliability and sensitivity of this algorithm. This algorithm has good prospect of engineering application in the EHV transformer protection.

关键词： Transformer protection

Arbitrary State Transition of Open Qubit system Based on Switching control

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arXiv 2024年

作者： Wu, Guangpu Xue, Shibei Ma, Shan Kuang, Sen Dong, Daoyi Petersen, Ian R. Department of Automation Shanghai Jiao Tong University Shanghai200240 China Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai200240 China Shanghai Engineering Research Center of Intelligent Control and Management Shanghai200240 China School of Automation Central South University Changsha410083 China Department of Automation University of Science and Technology of China Hefei230027 China School of Engineering Australian National University CanberraACT2601 Australia

We present a switching control strategy based on Lyapunov control for arbitrary state transitions in open qubit systems. With coherent vector representation, we propose a switching control strategy, which can prevent the state of the qubit from entering invariant sets and singular value sets, effectively driving the system ultimately to a sufficiently small neighborhood of target states. In comparison to existing works, this control strategy relaxes the strict constraints on system models imposed by special target states. Furthermore, we identify conditions under which the open qubit system achieves finite-time stability (FTS) and finite-time contractive stability (FTCS), respectively. This represents a critical improvement in quantum state transitions, especially considering the asymptotic stability of arbitrary target states is unattainable in open quantum systems. The effectiveness of our proposed method is convincingly demonstrated through its application in a qubit system affected by various types of decoherence, including amplitude, dephasing and polarization decoherence. Copyright © 2024, The Authors. All rights reserved.

关键词： Asymptotic stability

Using Inverse Distance Weighting and Pb Isotopic Compositions Reveal Source Contribution and Transfer Mechanism of Pb in Soil-Wheat system: A Case Study of Suburban Farmland

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SSRN

SSRN 2023年

作者： Chen, Zhifan Li, Yipeng Yang, Mengyang Zhou, Han Wu, Di Ding, Renqi Ruan, Xinling Li, Zhihong Ministry of Education Kaifeng475004 China Henan Engineering Research Center for Control & Remediation of Soil Heavy Metal Pollution Henan University Kaifeng475004 China Henan Key Laboratory of Earth System Observation and Modeling Henan University Kaifeng475004 China MLR Key Laboratory of Isotope Geology Institute of Geology Chinese Academy of Geological Sciences Beijing100037 China

This study combined Pb isotopic compositions and inverse distance weighting (IDW) to quantitatively identify contribution rates of different Pb sources for various compartments of soil-wheat system and explored the uptake, transfer pathway and mechanisms of Pb in soil-wheat system in the suburban farmlands of Kaifeng, China. The Pb isotopic compositions in soil-wheat system and environmental samples were measured by multi-collector inductively coupled plasma mass spectrometry. The results showed that the average Pb contents were in order of soil > root > stem > shell > grain, which 18.2% of Pb contents in grain samples were above the national food safe standard for Pb (0.2mg kg-1). Translocation factors of Pb were ranked as TF shell/stem > TF root/soil > TF stem/root > TF grain/shell > TF grain/stem. Quantitative source identification displayed that sewage irrigation gave a decreasing contribution (30.60 % - 67.74 %) from root, soil, wheat stem, shell, leaf to grain, while the contribution of atmospheric deposition had an increasing tendency (30.69 % - 68.62 %). Totally, lighter Pb isotopes from atmospheric deposition are more easily absorbed by leaves and preferably enriched in wheat grains, while wheat roots and stems are the main retention sites of heavier Pb isotopes from sewage irrigation. The result implied that Pb in wheat grains was primarily contributed by atmospheric deposition, wheat roots and stems play an irresistible role in blocking heavy Pb isotopes, effectively decreasing heavy Pb isotopes into wheat grains, thus greatly reducing Pb health risks in wheat grain. Therefore, reasonable adjustment of rhizosphere soil and atmospheric environment or physiological interference on wheat growth might be an effective way to reduce the risk of Pb enrichment in wheat grains. The study gave us a new insight into elucidating uptake, migration pathway and mechanisms of Pb in soil-wheat system. © 2023, The Authors. All rights reserved.

关键词： Soils

Two points are enough

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arXiv 2024年

作者： Liu, Hao Zhao, Yanbin Zheng, Huarong Fan, Xiulin Deng, Zhihua Chen, Mengchi Wang, Xingkai Liu, Zhiyang Lu, Jianguo Chen, Jian State Key Laboratory of Fluid Power Components and Mechatronic Systems School of Mechanical Engineering Zhejiang University Hangzhou China Ocean College Zhejiang University Hangzhou China State Key Laboratory of Silicon and Advanced Semiconductor Materials School of Materials Science and Engineering Zhejiang University Hangzhou China Nanyang Technological University Singapore School of Control Science and Engineering Zhejiang University Hangzhou China School of Materials Science and Engineering Tianjin University Tianjin China School of System Design and Intelligent Manufacturing Southern University of Science and Technology Shenzhen China

Prognosis and diagnosis play an important role in accelerating the development of lithium-ion batteries, as well as reliable and long-life operation. In this work, we answer an important question: What is the minimum amount of data required to extract features for accurate battery prognosis and diagnosis? Based on the first principle, we successfully extracted the best two-point feature (BTPF) for accurate battery prognosis and diagnosis using the fewest data points (only two) and the simplest feature selection method (Pearson correlation coefficient). The BTPF extraction method is tested on 820 cells from 6 open-source datasets (covering five different chemistry types, seven manufacturers, and three data types). It achieves comparable accuracy to state-of-the-art features in both prognosis and diagnosis tasks. This work challenges the cognition of existing studies on the difficulty of battery prognosis and diagnosis tasks, subverts the fixed pattern of establishing prognosis and diagnosis methods for complex dynamic systems through deliberate feature engineering, highlights the promise of data-driven methods for field battery prognosis and diagnosis applications, and provides a new benchmark for future studies. Copyright © 2024, The Authors. All rights reserved.

关键词： Lithium-ion batteries

fMRI-based Brain Disease Diagnosis: A Graph Network Approach

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TechRxiv

TechRxiv 2023年

作者： Chen, Qi-Qi Gao, Yubing Tong, Wei Li, Ping Wu, Edmond Q. The Department of Automation Shanghai Jiao Tong University Shanghai200240 China The Nanjing University of Science and Technology Jiangsu210008 China The School of Biological Science and Medical Engineering Beihang University Beijing100191 China The Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai Jiao Tong University Shanghai200240 China The Shanghai Engineering Research Center of Intelligent Control and Management Shanghai Jiao Tong University Shanghai200240 China

As a non-invasive brain imaging technology, functional magnetic resonance imaging (fMRI) provides a basic tool for brain functional network modeling and brain disease diagnosis. Problems, such as large number of parameters, low training efficiency, and poor interpretability, are encountered in mainstream models because of the high complexity of fMRI and brain networks. To solve these problems, a novel structure feature combined graph neural network (SFC-GNN) with a low number of parameters is proposed. In particular, SFC-GNN is composed of 1) the graph convolution layer of the brain region perception and 2) the node pooling layer of the graph structure feature (GSF). It also receives the sparse brain graph modeled by each subject’s fMRI as input. Especially, the GSF layer can select brain regions that are important for classification, thereby localizing all active regions related to brain disease. Moreover, a group network is constructed according to the correlation among subjects, and SFC-GNN can be extended further to a node classification model to achieve better diagnosis performance. The proposed method has been validated on the ABIDE and ADNI datasets, thereby showing the effectiveness of our proposed method in various experiments. © 2023, CC BY.

关键词： Magnetic resonance imaging

An application of fractional intelligent robust controller for electromechanical valve

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An application of fractional intelligent robust controller f...

World Congress on Information and Communication Technologies (WICT)

作者： Tribeni Prasad Banerjee Suman Saha Swagatam Das Ajith Abraham Department of Electronics and Telecommunication Engineering Jadavpur University Kolkata India Drives and Control System Laboratory CSIR-Central Mechanical Engineering Research Institute Durgapur West Bengal India IT For Innovations EU Center of excellence Faculty of Electrical Engineering and Computer Science VSB-Technical University of Ostrava Czech Republic Scientific Network for Innovation and Research Excellence Machine Intelligence Research Laboratories-MIR Laboratories WA USA

The paper analyzed and model of a fault tolerant electromechanical controlled worm gear driven fuel shut off valve for aerospace application. The analysis is mainly on design a reduced order fractional controller. This is for controlling the velocity of worm gear so that the friction torque due to uneven rotational speed can be avoided. Because with the friction and stiction and backlash the valve system performance is reduced and more and more unstable this leads the system to failure. The proposed controller can provide robustness against the uncertain loading torque and system parameter.

关键词： Valves Gears Equations control systems Robustness Mathematical model Torque

DiffRoad: Realistic and Diverse Road Scenario Generation for Autonomous Vehicle Testing

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arXiv 2024年

作者： Zhou, Junjie Wang, Lin Meng, Qiang Wang, Xiaofan Department of Automation Shanghai Jiao Tong University Key Laboratory of System Control and Information Processing Ministry of Education of China Shanghai200240 China Department of Automation Shanghai Jiao Tong University School of Mechatronic Engineering and Automation Shanghai University School of Electrical and Electronic Engineering Shanghai Institute of Technology Shanghai201418 China Department of Civil and Environmental Engineering National University of Singapore Singapore117576 Singapore

Generating realistic and diverse road scenarios is essential for autonomous vehicle testing and validation. Nevertheless, owing to the complexity and variability of real-world road environments, creating authentic and varied scenarios for intelligent driving testing is challenging. In this paper, we propose DiffRoad, a novel diffusion model designed to produce controllable and high-fidelity 3D road scenarios. DiffRoad leverages the generative capabilities of diffusion models to synthesize road layouts from white noise through an inverse denoising process, preserving real-world spatial features. To enhance the quality of generated scenarios, we design the Road-UNet architecture, optimizing the balance between backbone and skip connections for high-realism scenario generation. Furthermore, we introduce a road scenario evaluation module that screens adequate and reasonable scenarios for intelligent driving testing using two critical metrics: road continuity and road reasonableness. Experimental results on multiple real-world datasets demonstrate DiffRoad’s ability to generate realistic and smooth road structures while maintaining the original distribution. Additionally, the generated scenarios can be fully automated into the OpenDRIVE format, facilitating generalized autonomous vehicle simulation testing. DiffRoad provides a rich and diverse scenario library for large-scale autonomous vehicle testing and offers valuable insights for future infrastructure designs that are better suited for autonomous vehicles. Copyright © 2024, The Authors. All rights reserved.

关键词： Automobile testing