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Mediterranean Conference on Control and Automation (MED)

作者： Vassilios Yfantis Nigora Gafur Achim Wagner Martin Ruskowski Department of Mechanical and Process Engineering Chair of Machine Tools and Control Systems Technische Universit&#x00E4 t Kaiserslautern Kaiserslautern Germany German Research Center for Artificial Intelligence (DFKI) Kaiserslautern Germany

ISBN: (数字)9781665406734

ISBN: (纸本)9781665406741

This paper presents a dual decomposition-based distributed optimization algorithm and applies it to distributed model predictive control (DMPC) problems. The considered DMPC problems are coupled through shared limited resources. Lagrangian duality can be used to decompose an MPC problem, so that each subsystem can compute its individual resource utilization, without sharing information, such as dynamics or constraints, with the other subsystems. The feasibility of the central problem is ensured by the coordination of the subproblems through dual variables which can be interpreted as prices on the shared limited resources. The proposed coordination algorithm makes efficient use of information collected from previous iterations by performing a quadratic approximation of the dual function of the central MPC problem. Aggressive update steps of the dual variables are prevented through a covariance-based step size constraint. The nonsmoothness encountered in dual optimization problems is addressed by the construction of cutting planes, similar to bundle methods for nonsmooth optimization. The cutting planes ensure that the updated dual variables do not lie outside the range of validity of the dual approximation. The proposed algorithm is evaluated on a two-tank system and compared to the standard subgradient method. The results show that the rate of convergence towards the centralized solution can be significantly improved while still preserving privacy between the subsystems through limited information exchange.

关键词： Privacy Heuristic algorithms Prediction algorithms approximation algorithms Dynamic scheduling Resource management Optimization

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An Approximate Least-Squares Method for Fast Gridless Radar Imaging

An Approximate Least-Squares Method for Fast Gridless Radar ...

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IEEE International Symposium on Geoscience and Remote Sensing (IGARSS)

作者： Longhui Wang Zhanyang Ai Jian Wang Department of Electronic Engineering Tsinghua University Beijing P.R.China Aerospace Information Research Institute Chinese Academy of Sciences Beijing P.R.China

ISBN: (数字)9798350360325

ISBN: (纸本)9798350360332

This paper presents a fast method called approximate least-squares (ALS) algorithm to address the off-grid problem in tomographic synthetic aperture radar (TomoSAR) imaging. First, we give the model of TomoSAR imaging and formulate the off-grid optimization problem. Next, we propose ALS algorithm to solve the optimization problem. ALS uses the second-order approximation of Taylor expansion to represent the off-grid optimization problem, and gives approximate closed-form solution for fast processing. Finally, numerical simulations confirm that ALS achieves gridless TomoSAR imaging faster while ensuring performance.

关键词： Imaging Radar imaging Tomography approximation algorithms Taylor series Numerical simulation Real-time systems

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A Low-Complexity and High-Quality Reconstruction Algorithm for Terahertz Single-Pixel Imaging

A Low-Complexity and High-Quality Reconstruction Algorithm f...

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International Conference on Signal Processing and Communication Systems, ICSPCS

作者： Chieh-Li Wang Yuan-Hao Huang Department of Electric Engineering Natioinal Tsing Hua University Hsinchu Taiwan R.O.C

ISBN: (数字)9798350389630

ISBN: (纸本)9798350389647

Single-pixel imaging is a promising technique for Terahertz (THz) imaging, because it can largely reduce the numbers of expensive THz emitter and detector. Single-pixel imaging uses compressive sensing (CS) to measure the compressed THz signal and to recover the object image. This work presents a low-complexity and high-quality total variation augmented Lagrangian method (2D-TVALM) algorithm based on the well-known total variation augmented Lagrangian alternating-direction algorithm (TVAL3). TVAL3 is a convex optimization algorithm used to solve the problem of total variation (TV) regularization. By designing the sampling matrix and some mathematic approximation, this work largely reduces the computational complexity and speed up the convergence. The simulation results show that the reconstruction quality of the proposed algorithm is about 7 dB higher than TVAL3 in PSNR and the performance is much better than that of the other CS algorithms. In the computation time, the proposed algorithm is about 31 times faster than TVAL3. Finally, the average PSNR and elapsed time of the proposed algorithm are 38.43 dB and 0.0558 s respectively with 200 iterations in the 15 test patterns.

关键词： Terahertz wave imaging TV Simulation Signal processing algorithms Signal processing approximation algorithms Sensors Computational complexity Image reconstruction Terahertz communications

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Throughput Enhancement of Full-Duplex CSMA Networks Using Multiplayer Bandits

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IEEE INTERNET OF THINGS JOURNAL 2021年第15期8卷 11807-11821页

作者： Tong, Jingwen Fu, Liqun Han, Zhu Xiamen Univ Sch Informat Xiamen 361005 Peoples R China Univ Houston Dept Elect & Comp Engn Houston TX 77004 USA Xiamen Univ Minist Educ Key Lab Underwater Acoust Commun & Marine Informa Xiamen 361005 Peoples R China Kyung Hee Univ Dept Comp Sci & Engn Seoul 446701 South Korea

This article studies the network-level throughput of a full-duplex (FD)-enabled CSMA network, considering the link's transmit power (TP) control, carrier-sensing threshold (CST) adjustment, and logarithm access intensity (LAI) adaptation. With the FD technique, a transmitter-receiver pair can transmit and receive simultaneously in the same frequency band. We aim to find the best combination of TP, CST, and LAI for each link to maximize the FD-CSMA network throughput. However, adjusting each link's TP and CST will change the network's carrier-sensing relation or contention graph, consequently leading to a computationally intractable network optimization problem. On the other hand, it is difficult to jointly optimize these three parameters in a fully distributed network. To overcome these, we first decompose this network optimization problem into two subproblems: 1) a joint control and scheduling problem in the transport- and media access control (MAC)-layer and 2) a parameter selection problem in the PHY-layer. Then, the multiplayer multiarmed bandit (MPMAB) framework has been introduced to address this problem by solving the two subproblems alternately. We put forth a fully distributed algorithm, named the stochastic and adversarial optimal FD-CSMA (SAO-FD-CSMA) algorithm, to solve the MPMAB problem by taking advantage of the optimization tool and the bandit theory. The numerical results show that the proposed algorithm outperforms the state-of-the-art bandit algorithms and can improve the network throughput by 43% compared with the random selection method.

关键词： Multiaccess communication Throughput Optimization Stochastic processes approximation algorithms Tuning Internet of Things CSMA full duplex (FD) multiplayer multiarmed bandit (MPMAB) stochastic and adversarial optimal FD-CSMA (SAO-FD-CSMA) algorithm

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Contiguous Allocation of Indivisible Items on a Path

arXiv

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arXiv 2024年

作者： Kawase, Yasushi Roy, Bodhayan Sanpui, Mohammad Azharuddin The University of Tokyo Japan Indian Institute of Technology Kharagpur India

We study the problem of allocating indivisible items on a path among agents. The objective is to find a fair and efficient allocation in which each agent’s bundle forms a contiguous block on the line. We say that an instance is (a, b)-sparse if each agent values at most a items positively and each item is valued positively by at most b agents. We demonstrate that, even when the valuations are binary additive, deciding whether every item can be allocated to an agent who wants it is NP-complete for the (4, 3)-sparse instances. Consequently, we provide two fixed-parameter tractable (FPT) algorithms for maximizing utilitarian social welfare, with respect to the number of agents and the number of items. Additionally, we present a 2-approximation algorithm for the special case when the valuations are binary additive, and the maximum utility is equal to the number of items. Also, we provide a 1/a-approximation algorithm for the (a, b)-sparse instances. Furthermore, we establish that deciding whether the maximum egalitarian social welfare is at least 2 or at most 1 is NP-complete for the (6, 3)-sparse instances, even when the valuations are binary additive. We present a 1/a-approximation algorithm for maximizing egalitarian social welfare for the (a, b)-sparse instances. Besides, we give two FPT algorithms for maximizing egalitarian social welfare in terms of the number of agents and the number of items. We also explore the case where the order of the blocks of items allocated to the agents is predetermined. In this case, we show that both maximum utilitarian social welfare and egalitarian social welfare can be computed in polynomial time. However, we determine that checking the existence of an EF1 allocation is NP-complete, even when the valuations are binary additive. Copyright © 2024, The Authors. All rights reserved.

关键词： approximation algorithms

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Low Cost 3D Scanner Using Iterative Closest Point Algorithm

Low Cost 3D Scanner Using Iterative Closest Point Algorithm

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Intelligent Systems and Embedded Design (ISED), International Conference on

作者： Arushi Sreekumar Renuka Devi S M Hemalatha T. Bappadittya Roy Electronics and Communication Department G. Narayanamma Institute of Technology and Science Hyderabad India Department of ECE Vijaya Institute of Technology for Women Enikepadu India School of Electronics Engineering VIT-AP University Amaravati India

ISBN: (数字)9798331522612

ISBN: (纸本)9798331522629

3D reconstruction is widely used to create 3D representation of 2D images. 3D scanner is a device that takes scans or images of the object or environment and creates the 3D representation of it. While industrial 3D scanners use laser technology to do the scanning, the central goal of this work is to compare cost effective ways of 3D scanning and comparing their performance. In this work we use a camera to capture RGBD images then use three different techniques namely, the hardcoded meth to reconstruct the objects, SIFT algorithm and the ICP algorithm. The results demonstrate that the ICP method yields the most reliable reconstructions, evidenced by Root Mean Square Error (RMSE) values approximately 0.0022 and fitness values reaching 0.9, indicating accuracy for objects such as a Rubik's cube and an orange fruit.

关键词： Point cloud compression Three-dimensional displays Costs Accuracy Iterative closest point algorithm Transforms Neural radiance field approximation algorithms Reliability Image reconstruction

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Real-Time Obstacle Detection and Localization for USV Using Stereo Vision and Edge Computing

Real-Time Obstacle Detection and Localization for USV Using ...

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Artificial Intelligence of Things and Systems (AIoTSys), International Conference on

作者： Di Wang Haiming Chen MD Asif Hasan Weihao Zhang Yuqing Hu Faculty of Electrical Engineering and Computer Science Ningbo University Ningbo Zhejiang China Information Center Ningbo Polytechnic Ningbo Zhejiang China Ningbo Industrial Internet Research Institute Ningbo Zhejiang China

ISBN: (数字)9798331507886

ISBN: (纸本)9798331507893

Unmanned Surface Vessel (USV) is widely used in various fields, and obstacle avoidance is a key technology for USV. Accurately detecting the position and type of obstacles is crucial for obstacle avoidance. Active sensors can accurately detect the position of obstacles but cannot distinguish their types, necessitating the use of vision sensors. Therefore, this paper employs stereo vision and proposes a stereo obstacle detection and localization method, based on SGBM and YOLOv5. The SGBM algorithm generates depth information, while the YOLOv5 algorithm detects the position of obstacles in the image. To address the issue of errors in measuring the continuous position of obstacles, this paper uses a Kalman filter to smooth the trajectory. Experimental results show that the proposed method improves obstacle localization accuracy by approximately 38% compared to raw measurements. Besides, considering the energy constraints and computing capabilities of lightweight USV, which cannot meet the demands of processing vision tasks, this paper introduces an edge-device collaboration architecture, by offloading the USV computing tasks to edge nodes, thereby extending the computing capacity and energy efficiency of the USV. Experimental results indicate that the proposed architecture meets the real-time obstacle avoidance requirements of USV.

关键词： Location awareness YOLO Accuracy Image edge detection Computer architecture approximation algorithms Stereo vision Trajectory Collision avoidance Underactuated surface vessels

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Design and Implementation of Array Multiplier Using 2-Bit Accurate and Approximate Adder

Design and Implementation of Array Multiplier Using 2-Bit Ac...

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PhD Colloquium on Ethically Driven Innovation and Technology for Society (PhD EDITS)

作者： R.V Nithyashree V. Yoga Priya G. Nikhil Kumar Reddy Shashidhar Tantry Department of ECE PES University Banglore Karnataka

ISBN: (数字)9798331541965

ISBN: (纸本)9798331541972

In this work, a design approach for array multipliers using approximate adders is presented. Our approach focuses on improving efficiency mainly in terms of resource usage and area. We have implemented multiplier by using 2-bit approximation adders and are used in 4-bit and 8-bit array multiplier configuration for the validation. Comparative results of these circuits with existing designs proves that our approach reduces resource usage and area by 10% however adding error by 5-10%. The designed approximate multipliers were tested on image processing algorithm implementation.

关键词： Technological innovation Accuracy Image processing approximation algorithms Delays MATLAB Adders

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Observability of Koopman Representations and Output Canonical Extended Dynamic Mode Decomposition

Observability of Koopman Representations and Output Canonica...

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IEEE Conference on Decision and Control

作者： Hyunsang Park Inseok Hwang School of Aeronautics and Astronautics Purdue University West Lafayette IN USA

ISBN: (数字)9798350316339

ISBN: (纸本)9798350316346

The Koopman operator has gained considerable attention due to its ability to represent a nonlinear system as a high-dimensional linear system through nonlinear lifting of the state space. While many algorithms have been proposed to approximate a Koopman representation from data, most assume full knowledge of the state information, whereas, in many applications, only the system’s output may be available. System identification with output data relies on the observability of the system in question, however, whether the Koopman representation is observable for an observable nonlinear system remains an open question. This paper bridges the gap by showing the existence of a locally faithful, observable Koopman representation for a nonlinear system that is locally weakly observable. Based on this finding, we propose a data-driven algorithm, called Observable Canonical Extended Dynamic Mode Decomposition, which can approximate the Koopman representation directly from output data. By leveraging the observable canonical form for multiinput multi-output linear systems, the proposed algorithm enables the identification of Koopman representations with a minimal number of parameter estimates, accurately capturing the dynamics of the underlying nonlinear system using only the output data. The efficacy of the theory demonstrated with analytic Koopman representations and data-driven estimator design for a few illustrative example systems.

关键词： Linear systems Heuristic algorithms Artificial neural networks Observers approximation algorithms Control systems Nonlinear dynamical systems System identification Observability

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Synchronization Process Analysis of Line Start Permanent Magnet Synchronous Machine

Synchronization Process Analysis of Line Start Permanent Mag...

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International Conference on Electrical Machines, ICEM

作者： Junli Huang Shanming Wang Wenmao Liu Department of Electrical Engineering Tsinghua University Beijing China

ISBN: (数字)9798350370607

ISBN: (纸本)9798350370614

Ahstract-Line-start permanent magnet synchronous machines (LSPMSM) can start without converters, enabling them to replace asynchronous machines in low-cost industrial applications. The starting process of line-start interior permanent magnet synchronous machine(LS-IPMSM) still lacks accurate analysis. In this paper, we use the quasi-static method to simplify the five-rank dq0 model to a two-rank model. A new method is proposed to compute the synchronous capability of LSPMSMs based on the simplified model. Simulation results show the high accuracy of the simplified model during the starting process and the effectiveness of the proposed method to compute the starting capability for LS-IPMSMs compared to the conventional method.

关键词： Permanent magnet machines Accuracy Torque Computational modeling Simulation Rotors Stators approximation algorithms Permanent magnets Synchronization

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