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arXiv 2024年

作者： Liu, Shuai Wu, Bo-Han Huang, Jeffrey Zhang, Zheshen Department of Electrical Engineering and Computer Science The University of Michigan Ann ArborMI48109 United States Research Laboratory of Electronics Massachusetts Institute of Technology CambridgeMA02139 United States

Bound states in the continuum (BIC) holds significant promise in manipulating electromagnetic fields and reducing losses in optical structures, leading to advancements in both fundamental research and practical applications. Despite their observation in various optical systems, the behavior of BIC in whispering-gallery-modes (WGMs) optical microcavities, essential components of photonic integrated chips, has yet to be thoroughly explored. In this study, we propose and experimentally identify a robust mechanism for generating quasi-BIC in a single deformed microcavity. By introducing boundary deformations, we construct stable unidirectional radiation channels as leaking continuum shared by different resonant modes and experimentally verify their external strong mode coupling. This results in drastically suppressed leaking loss of one originally long-lived resonance, manifested as more than a 3-fold enhancement of its quality (Q) factor, while the other short-lived resonance becomes more lossy, demonstrating the formation of Friedrich-Wintgen quasi-BICs as corroborated by both the theoretical model and the experimental data. This research will provide a practical approach to enhance the Q factor of optical microcavities, opening up potential applications in the area of deformed microcavities, nonlinear optics, quantum optics, and integrated photonics. © 2024, CC BY.

关键词： Quantum optics

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Efficient Arm Motion Planning with Reduced Viapoints for Mars Rover Operations

Efficient Arm Motion Planning with Reduced Viapoints for Mar...

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Space Robotics (iSpaRo), International Conference on

作者： Justin Huang Valen Yamamoto Ana Warner Jet Propulsion Laboratory California Institute of Technology Pasadena CA Department of Electrical Engineering and Computer Science UC Irvine Irvine CA Department of Robotics University of Michigan Ann Arbor MI

ISBN: (数字)9798350367232

ISBN: (纸本)9798350367249

This paper describes additions and enhancements we made to the standard RRT-Connect motion planning algorithm to suit the unique needs of operating the robotic arm on the Perseverance Mars Rover. One constraint we have is to maintain a minimum distance between the terrain and any part of the arm hardware. Another goal specific to rover planning is to minimize the number of viapoints in our motion plans. These algorithms should also run efficiently so that rover planners can generate arm motion sequences in time for uplink windows. We applied the RRT-Connect algorithm to the rover’s robotic arm and tested its performance, and we found that it could be used successfully for rover planning with a few changes. First, we implemented the terrain clearance requirement using a software tool called Proximeter. Second, we simplify the paths computed by RRT-Connect to minimize the number of viapoints in a motion plan. Third, we leverage Proximeter to reduce the number of expensive terrain collision checks done by the algorithm, speeding up motion planning.

关键词： Space vehicles Mars Costs Software algorithms Manipulators Hardware Planning

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Joint Server Activation and Network Slice Deployment in Mobile Edge Computing Networks

Joint Server Activation and Network Slice Deployment in Mobi...

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IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Yijian Hou Kaisa Zhang Zibin Chen Xuewen Liu Gang Chuai Weidong Gao Xiangyu Chen Key Laboratory of Universal Wireless Communication Ministry of Education Beijing University of Posts and Telecommunications Beijing China Department of Electrical and Computer Engineering University of Massachusetts Amherst MA U.S.A

ISBN: (数字)9798350362244

ISBN: (纸本)9798350362251

Network slicing provides personalized services by building isolated logical networks. Besides, through deploying Virtual Network Function (VNF) chains on Mobile Edge Computing (MEC) servers, network slicing can guarantees the performance of low-latency services. To reduce maintenance costs, it is necessary to optimize the deployment of both the slices’ access functions on the base stations and the VNF chains on the MEC servers. Meanwhile, optimizing MEC server activation can save energy while meeting service demands. There have been many studies focusing on MEC server activation, access function deployment, and VNF chain deployment, but no work has considered them simultaneously. To fill this research gap, we construct a joint server activation as well as the access functions and VNF chains deployment model, aiming to guarantee performance while minimizing the cost. This problem is a mixed-integer nonlinear programming problem which is hard to be solved. Thus, we decompose the problem and design a Deep Q Network (DQN)based three-stage algorithm. Numerical results demonstrate the superiority of the proposed scheme over the baseline methods.

关键词： Costs Multi-access edge computing Network slicing Clustering algorithms Quality of service Programming Numerical models Maintenance Servers Optimization

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Optimal Power Control Based-Metaheuristic Algorithm Based Variable Speed Wind Energy System of DFIG

Optimal Power Control Based-Metaheuristic Algorithm Based Va...

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International Smart Grid Workshop and Certificate Program (ISGWCP)

作者： Boussaid Ibrahim Harrouz Abdelkader Merahi Farid Ibrahim Yaichi Ilhami Colak Korhan Kayisli Virgil Dumbrava Electrical Engineering Department Laboratory of sustainable development and computer science (LDDI) University of Adrar Adrar Algeria Laboratory of sustainable development and computer science (LDDI) University of Adrar Adrar Algeria Electrical Engineering Department Automatic Laboratory of Setif University of Ferhat Abbas Setif1 Setif Algeria Department of Electrical Electronics Eng. Faculty of Engineering Architecture Nisantasi University Istanbul Turkey Department of Electric Power Systems Polytechnic University of Bucharest Bucharest Romania

This article presents a novel method for controlling a doubly fed induction generator (DFIG) wind energy system in the presence of variable wind speeds. In order to achieve decoupling control of the active and reactive power, the rotor-side converter (RSC) of the DFIG is controlled using field-oriented control (FOC). The system is very complicated and nonlinear, making it challenging to adjust the PI gains appropriately. The present research proposes the utilization of the Grey Wolf Optimization (GWO) algorithm as an approach to optimize the gains of a Proportional-Integral (PI) regulator. The simulation results demonstrate that the GWO-PI provides a lower criterion value and an improved response than the conventional PI.

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The Entrapment Problem in Random Walk Decentralized Learning

arXiv

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arXiv 2024年

作者： Liu, Zonghong Rouayheb, Salim El Dwyer, Matthew Department of Electrical and Computer Engineering Rutgers University New BrunswickNJ United States Network Cyber and Computational Sciences Division DEVCOM Army Research Laboratory AdelphiMD United States

This paper explores decentralized learning in a graph-based setting, where data is distributed across nodes. We investigate a decentralized SGD algorithm that utilizes a random walk to update a global model based on local data. Our focus is on designing the transition probability matrix to speed up convergence. While importance sampling can enhance centralized learning, its decentralized counterpart, using the Metropolis-Hastings (MH) algorithm, can lead to the entrapment problem, where the random walk becomes stuck at certain nodes, slowing convergence. To address this, we propose the Metropolis-Hastings with Lévy Jumps (MHLJ) algorithm, which incorporates random perturbations (jumps) to overcome entrapment. We theoretically establish the convergence rate and error gap of MHLJ and validate our findings through numerical experiments. Copyright © 2024, The Authors. All rights reserved.

关键词： Contrastive Learning

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Prediction of Acoustic Communication Performance for AUVs using Gaussian Process Classification

Prediction of Acoustic Communication Performance for AUVs us...

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IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS)

作者： Yifei Gao Harun Yetkin McMahon James Daniel J. Stilwell Bradley Department of Electrical and Computer Engineering Virginia Tech Blacksburg VA USA Bartin University Acoustics Division Code 7130 US Naval Research Laboratory Washington D.C.

ISBN: (数字)9798350377705

ISBN: (纸本)9798350377712

Cooperating autonomous underwater vehicles (AUVs) often rely on acoustic communication to coordinate their actions effectively. However, the reliability of underwater acoustic communication decreases as the communication range between vehicles increases. Consequently, teams of cooperating AUVs typically make conservative assumptions about the maximum range at which they can communicate reliably. To address this limitation, we propose a novel approach that involves learning a map representing the probability of successful communication based on the locations of the transmitting and receiving vehicles. This probabilistic communication map accounts for factors such as the range between vehicles, environmental noise, and multi-path effects at a given location. In pursuit of this goal, we investigate the application of Gaussian process binary classification to generate the desired communication map. We specialize existing results to this specific binary classification problem and explore methods to incorporate uncertainty in vehicle location into the mapping process. Furthermore, we compare the prediction performance of the probability communication map generated using binary classification with that of a signal-to-noise ratio (SNR) communication map generated using Gaussian process regression. Our approach is experimentally validated using communication and navigation data collected during trials with a pair of Virginia Tech 690 AUVs.

关键词： Uncertainty Acoustic communication (telecommunication) Navigation Working environment noise Gaussian processes Probabilistic logic Reliability Underwater acoustics Intelligent robots Signal to noise ratio

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Safety-Critical Control of Euler-Lagrange Systems Subject to Multiple Obstacles and Velocity Constraints

arXiv

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arXiv 2024年

作者： Liu, Zhi Wu, Si Liu, Tengfei Jiang, Zhong-Ping State Key Laboratory of Synthetical Automation for Process Industries Northeastern University Shenyang110004 China Department of Electrical and Computer Engineering New York University BrooklynNY11201 United States

This paper studies the safety-critical control problem for Euler-Lagrange (EL) systems subject to multiple ball obstacles and velocity constraints in accordance with affordable velocity ranges. A key strategy is to exploit the underlying inner-outer-loop structure for the design of a new cascade controller for the class of EL systems. In particular, the outer-loop controller is developed based on quadratic programming (QP) to avoid ball obstacles and generate velocity reference signals fulfilling the velocity limitation. Taking full advantage of the conservation-of-energy property, a nonlinear velocity-tracking controller is designed to form the inner loop. One major difficulty is caused by the possible non-Lipschitz continuity of the standard QP algorithm when there are multiple constraints. To solve this problem, we propose a refined QP algorithm with the feasible set reshaped by an appropriately chosen positive basis such that the feasibility is retained while the resulting outer-loop controller is locally Lipschitz. It is proved that the constraint-satisfaction problem is solvable as long as the ball obstacles satisfy a mild distance condition. The proposed design is validated by numerical simulation and an experiment based on a 2-link planar manipulator. Copyright © 2024, The Authors. All rights reserved.

关键词： Quadratic programming

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Fitting an immersed submanifold to data via Sussmann’s orbit theorem

Fitting an immersed submanifold to data via Sussmann’s orbi...

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IEEE Conference on Decision and Control

作者： Joshua Hanson Maxim Raginsky Department of Electrical and Computer Engineering and the Coordinated Science Laboratory University of Illinois at Urbana-Champaign Urbana IL

ISBN: (数字)9781665467612

ISBN: (纸本)9781665467629

This paper describes an approach for fitting an immersed submanifold of a finite-dimensional Euclidean space to random samples. The reconstruction mapping from the ambient space to the desired submanifold is implemented as a composition of an encoder that maps each point to a tuple of (positive or negative) times and a decoder given by a composition of flows along finitely many vector fields starting from a fixed initial point. The encoder supplies the times for the flows. The encoder-decoder map is obtained by empirical risk minimization, and a high-probability bound is given on the excess risk relative to the minimum expected reconstruction error over a given class of encoder-decoder maps. The proposed approach makes fundamental use of Sussmann’s orbit theorem, which guarantees that the image of the reconstruction map is indeed contained in an immersed submanifold.

关键词： Space vehicles Neural networks Fitting Orbits Mathematical models Manifold learning Risk management

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Influence of Defects on Enhancing Lithium Diffusivity in Crystalline Silicon Anodes for Fast Charging Lithium-Ion Batteries

SSRN

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SSRN 2024年

作者： Zand, Ali Lashani Mani, Azam Jalali, Hossein Kookhaee, Maryam Habibi, Alireza Sanaee, Zeinab Mousavi-Khoshdel, Seyed Morteza School of Electrical and Computer Engineering College of Engineering University of Tehran Tehran14395-515 Iran Department of Engineering Science College of Engineering University of Tehran Iran Industrial Electrochemistry Research Laboratory Faculty of Chemistry Iran University of Science and Technology Tehran*** Iran

The growing energy storage market requires safe and stable high-capacity cycling, silicon (Si) anodes are ideal for this purpose. Electrochemical reactions between Si anodes and lithium pose challenges due to the significant volumetric expansion during lithiation. Expansion material can cause cracks in the structure and result in disconnection from the current collector. Si anodes exhibit a variety array of phenomena, such as amorphization and crystallization upon full lithiation, with variations depending on crystal orientations. It is evident that Lithium ions (Li+) diffusion varies across different Si crystalline surfaces and arrangements. It is possible to improve ion mobility and reduce diffusion barriers through strategic design and the use of complementary materials. First principles simulations can provide fundamental insights into atomic interactions, offering a realistic atomistic representation of lithiation processes. Our simulations involve the step-by-step insertion of Li+ into Si orientations and Si with N vacancies. Atomic imaging of Si (110) doped with N vacancies reveals a more favorable behavior in ionic diffusion. Our results explain the ternary Si-Li-N electrode materials and the identification of optimal site disorders to maximize the rate of Li+ diffusion in crystalline Si anodes. © 2024, The Authors. All rights reserved.

关键词： Lithium-ion batteries

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Entangled Photons Based Particle-Level Temporal-Spatial Matching Processing in Quantum Radar

Entangled Photons Based Particle-Level Temporal-Spatial Matc...

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2021 CIE International Conference on Radar, Radar 2021

作者： Wang, Weihao Li, Jun Wei, Rongyu Guo, Qinghua Xidian University National Laboratory of Radar Signal Processing Xian China School of Electrical Computer and Telecommunications Engineering University of Wollongong Wollongong Australia

ISBN: (纸本)9781665498142

With the continuous development of quantum technology, entangled signal has been used in more and more fields. Due to the unique temporal-spatial correlation characteristics of entangled signal, it provides promising solutions to problems such as super-resolution and anti-interference. Especially in the context of weak signal, the entangled signal-based sensing is more prominent. In this paper, we present a quantum imaging framework based on particle level matching processing under the correlation characteristics of entangled photons. The temporal-spatial correlation property of the entangled photon is used to realize the matched filtering to accumulate the weak signals in time domain and reconstructed the target image in spatial domain. © 2021 IEEE.

关键词： Entangled-photons imaging particle-level processing quantum radar

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