检索结果-内蒙古大学图书馆

Adaptive sliding mode back-stepping control for hypersonic flight vehicle with state constraints and unmodeled disturbances

学校读者我要写书评

暂无评论

Adaptive sliding mode back-stepping control for hypersonic f...

International Conference on control and Automation (ICCA)

作者： Fei Ma Yunjie Wu Xiaocen Liu Bohao Li Xiaodong Liu State Key Laboratory of Virtual Reality Technology and Systems Beihang University Beijing China School of Automation Science and Electrical Engineering Beihang University Beijing China and Technology on Aircraft Control Laboratory Beijing China Beijing Aerospace Automatic Control Institute Beijing China

ISBN: (数字)9781728190938

ISBN: (纸本)9781728190945

This study presents a finite-time adaptive sliding mode back-stepping controller (FASMBC) for hypersonic flight vehicle (HFV), where the state constraints and unmodeled disturbances are considered. Firstly, the longitudinal model of HFV is decomposed into altitude subsystem and velocity subsystem. Then, sliding mode control and back-stepping logic based on barrier Lyapunov function are merged to design the robust controller for each subsystem. Besides, the adaptive strategy is applied to estimate the unmodeled disturbances. A tracking differentiator is introduced to avoid the "explosion of terms" problem involved in traditional back-stepping control. Finally, the simulation results is provided to illustrate the effectiveness of the proposed control scheme.

关键词： Solid modeling Adaptation models Lyapunov methods Estimation Atmospheric modeling Two dimensional displays Three-dimensional displays

Analysis of factors affecting the precision of gene expression measurement methods

学校读者我要写书评

暂无评论

Analysis of factors affecting the precision of gene expressi...

International Conference on Signal Processing and Communication systems, ICSPCS

作者： Anna Lalik Krzysztof Puszyński Roman Jaksik Systems Engineering Group Faculty of Automatic Control Electronics and Automatic Control Electronics and Automatic Control Electronics and Informatics Informatics Informatics Silesian University of Technology Gliwice Poland

ISBN: (数字)9781728121949

ISBN: (纸本)9781728121956

Biological experiments which aim to study changes in the gene expression profile currently allow to detect only significant variations in RNA levels due to high variance of the signal in both biological and technical replicates. The variance of the signal has its source in the experimental procedure and in the laboratory in which the measurement was performed. Understanding factors that influence measured levels of gene expression, using individual platforms, will allow the development of bioinformatics tools correcting the impact of experimental methodology. In this study, we analyze the influence of selected factors (poly(A) and spacer-T motifs; GC content, transcript length) on the precision of gene expression measurements by RT-qPCR, oligonucleotide microarrays and RNA sequencing.

关键词： RNA Gene expression Probes Sequential analysis Real-time systems Informatics

Compositional Synthesis of Signal Temporal Logic Tasks via Assume-Guarantee Contracts

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Liu, Siyuan Saoud, Adnane Jagtap, Pushpak Dimarogonas, Dimos V. Zamani, Majid Department of Electrical and Computer Engineering Technical University of Munich Germany Computer Science Department LMU Munich Germany Laboratoire des Signaux et Systèmes CentraleSupélec Univ. Paris Saclay Gif sur Yvette France Robert Bosch Center for Cyber-Physical Systems in Indian Institute of Science Bangalore India Division of Decision and Control Systems KTH Royal Institute of Technology Stockholm Sweden Computer Science Department University of Colorado Boulder United States

In this paper, we focus on the problem of compositional synthesis of controllers enforcing signal temporal logic (STL) tasks over a class of continuous-time nonlinear interconnected systems. By leveraging the idea of funnel-based control, we show that a fragment of STL specifications can be formulated as assume-guarantee contracts. A new concept of contract satisfaction is then defined to establish our compositionality result, which allows us to guarantee the satisfaction of a global contract by the interconnected system when all subsystems satisfy their local contracts. Based on this compositional framework, we then design closed-form continuous-time feedback controllers to enforce local contracts over subsystems in a decentralized manner. Finally, we demonstrate the effectiveness of our results on two numerical examples. Copyright © 2022, The Authors. All rights reserved.

关键词： Continuous time systems

Real-time cross-fleet pareto-improving truck platoon coordination

学校读者我要写书评

暂无评论

arXiv 2022年

作者： Johansson, Alexander Sun, Xiaotong Mårtensson, Jonas Yin, Yafeng Integrated Transport Research Lab and Division of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology Stockholm Sweden StockholmSE-100 44 Sweden Department of Civil and Environmental Engineering University of Michigan 2350 Hayward St Ann ArborMI48109 United States

This paper studies a multi-fleet platoon coordination system in transport networks that deploy hubs to form trucks into platoons. The trucks belong to different fleets that are interested in increasing their profits by platooning across fleets. The profit of each fleet incorporates platooning rewards and costs for waiting at hubs. Each truck has a fixed route and a waiting time budget to spend at the hubs along its route. To ensure that all fleets are willing to participate in the system, we develop a cross-fleet Pareto-improving coordination strategy that guarantees higher fleet profits than a coordination strategy without cross-fleet platoons. By leveraging multiple hubs for platoon formation, the coordination strategy can be implemented in a real-time and distributed fashion while largely reducing the amount of travel information to be shared for system-wide coordination. We evaluate the proposed strategy in a simulation study over the Swedish transportation network. The cross-fleet platooning strategy significantly improves fleets' profits compared with single-fleet platooning, especially the profits from smaller fleets. The cross-fleet platooning strategy also shows strong competitiveness in terms of the system-wide profit compared to the case when a system planner optimizes all fleets' total profit. Copyright © 2022, The Authors. All rights reserved.

关键词： Profitability

A stochastic perturbed augmented Lagrangian method for smooth convex constrained minimization

学校读者我要写书评

暂无评论

arXiv 2025年

作者： Singh, Nitesh Kumar Necoara, Ion School of Computer Science University of Petroleum and Energy Studies Uttarakhand Dehradun248007 India Automatic Control and Systems Engineering Department University Politehnica Bucharest Bucharest060042 Romania Gheorghe Mihoc-Caius Iacob Institute of Mathematical Statistics and Applied Mathematics of the Romanian Academy Bucharest050711 Romania

This paper considers smooth convex optimization problems with many functional constraints. To solve this general class of problems we propose a new stochastic perturbed augmented Lagrangian method, called SGDPA, where a perturbation is introduced in the augmented Lagrangian function by multiplying the dual variables with a subunitary parameter. Essentially, we linearize the objective and one randomly chosen functional constraint within the perturbed augmented Lagrangian at the current iterate and add a quadratic regularization that leads to a stochastic gradient descent update for the primal variables, followed by a perturbed random coordinate ascent step to update the dual variables. We provide a convergence analysis in both optimality and feasibility criteria for the iterates of SGDPA algorithm using basic assumptions on the problem. In particular, when the dual updates are assumed to be bounded, we prove sublinear rates of convergence for the iterates of algorithm SGDPA of order O(k−1/2) when the objective is convex and of order O(k−1) when the objective is strongly convex, where k is the iteration counter. Under some additional assumptions, we prove that the dual iterates are bounded and in this case we obtain convergence rates of order O(k−1/4) and O(k−1/2) when the objective is convex and strongly convex, respectively. Preliminary numerical experiments on problems with many quadratic constraints demonstrate the viability and performance of our method when compared to some existing state-of-the-art optimization methods and software. © 2025, CC BY.

关键词： Lagrange multipliers

Automated Injuries Classification on Postmortem Images: A Deep Learning Approach with Different Neural Networks Architectures

学校读者我要写书评

暂无评论

SSRN

SSRN 2023年

作者： Kalinowska, Kamila Barbara Zawieska, Dorota Puchala, Sebastian Markiewicz, Jakub Stefan Kot, Patryk Wilkowski, Artur Krajewski, Pawel Fudalej, Marcin Soltyszewski, Ireneusz Department of Photogrammetry Remote Sensing and Spatial Information Systems Warsaw University of Technology Politechniki 1 Square Warsaw00-661 Poland Institute of Computer Science Warsaw University of Technology Politechniki 1 Square Warsaw00-661 Poland Research Institute Liverpool John Moores University Byrom Street LiverpoolL3 3AF United Kingdom Institute of Control and Computation Engineering Warsaw University of Technology Politechniki 1 Square Warsaw00-661 Poland Forensic Medicine Department Medical University of Warsaw 61 Żwirki and Wigury Street Warsaw02-091 Poland

The paper discusses a deep learning approach for automatically detecting the two most important classes of injuries (bruises and abrasions) with the use of semantic segmentation. First, a dataset of postmortem images of injuries is completed and fitting data pre-processing, and annotation methods for algorithm training and evaluation are developed. Second, end-to-end U-Net, FPN and LinkNet semantic segmentation network-based injuries detection algorithms are implemented on EfficientNetB3 and ResNet50 backbones. Third, an optimisation strategy for the network is employed to improve the algorithm's detection performance based on the data features of injuries. This technique entails data augmentation utilising a custom loss function and a combination of image transformation and class balancing. The experimental results demonstrated promising performance with high sensitivity and specificity for our best model called TIPPI (92,7% and 98,9%, respectively). TIPPI may be used to automatically analyse postmortem images. © 2023, The Authors. All rights reserved.

关键词： Metadata

Active Simultaneously Transmitting and Reflecting Surface Assisted NOMA Networks

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Yue, Xinwei Xie, Jin Ouyang, Chongjun Liu, Yuanwei Shen, Xia Ding, Zhiguo The Key Laboratory of Information and Communication Systems Ministry of Information Industry Beijing Information Science and Technology University Beijing100101 China The Key Laboratory of Modern Measurement & Control Technology Ministry of Education Beijing Information Science and Technology University Beijing100101 China The School of Information and Communication Engineering Beijing University of Posts and Telecommunications Beijing100876 China The School of Electronic Engineering and Computer Science Queen Mary University of London LondonE1 4NS United Kingdom Beijing100191 China The Department of Electrical Engineering and Computer Science Khalifa University Abu Dhabi United Arab Emirates Department of Electrical Engineering Princeton University Princeton United States

The novel active simultaneously transmitting and reflecting surface (ASTARS) has recently received a lot of attention due to its capability to conquer the multiplicative fading loss and achieve full-space smart radio environments. This paper introduces the ASTARS to assist non-orthogonal multiple access (NOMA) communications, where the stochastic geometry theory is used to model the spatial positions of pairing users. We design the independent reflection/transmission phase-shift controllers of ASTARS to align the phases of cascaded channels at pairing users. We derive new closed-form and asymptotic expressions of the outage probability and ergodic data rate for ASTARS-NOMA networks in the presence of perfect/imperfect successive interference cancellation (pSIC). The diversity orders and multiplexing gains for ASTARS-NOMA are derived to provide more insights. Furthermore, the system throughputs of ASTARS-NOMA are investigated in both delay-tolerant and delay-limited transmission modes. The numerical results are presented and show that: 1) ASTARS-NOMA with pSIC outperforms ASTARS assisted-orthogonal multiple access (ASTARS-OMA) in terms of outage probability and ergodic data rate;2) The outage probability of ASTARS-NOMA can be further reduced within a certain range by increasing the power amplification factors;3) The system throughputs of ASTARS-NOMA are superior to that of ASTARS-OMA in both delay-limited and delay-tolerant transmission modes. Copyright © 2024, The Authors. All rights reserved.

关键词： Stochastic systems

Temperature shift of magnetic field dependent photoluminescence features of nitrogen-vacancy ensembles in diamond

学校读者我要写书评

暂无评论

Physical Review B 2025年第9期111卷 094112-094112页

作者： Irena Rodzoń Xue Zhang Viktor Ivády Huijie Zheng Arne Wickenbrock Dmitry Budker Johannes Gutenberg-Universität Mainz Helmholtz-Institut Mainz GSI Helmholtzzentrum für Schwerionenforschung 55128 Mainz Germany School of Control Science and Engineering Dalian University of Technology Dalian 116024 China Department of Physics of Complex Systems ELTE Eötvös Loránd University Egyetem tér 1-3 H-1053 Budapest Hungary MTA-ELTE Lendület “Momentum” NewQubit Research Group Pázmány Péter Sétány 1/A 1117 Budapest Hungary Department of Physics Chemistry and Biology Linköping University 581 83 Linköping Sweden Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Department of Physics University of California Berkeley California 94720 USA

Recently significant attention has been paid to magnetic field dependent photoluminescence (PL) features of the negatively charged nitrogen-vacancy (NV) centers in diamond. These features are used for microwave-free sensing and are indicative of the spin-bath properties in the diamond sample. Examining the temperature dependence of the PL features allows identifying both temperature-dependent and -independent features, of potential utility in diamond-based quantum sensing and dynamic nuclear polarization applications. Here we study the thermal variability of many different features visible in a wide range of magnetic fields. To this end, we first discuss the origin of the features and tentatively assign the previously unidentified features to cross relaxation of NV center containing multispin systems. The experimental results are compared with theoretically predicted temperature shifts deduced from a combination of thermal expansion and electron-phonon interactions. A deeper insight into the thermal behavior of a wide array of the features may come with important consequences for various applications in high-precision NV thermometry, gyroscopes, solid-state clocks, and biomagnetic measurements.

关键词： Electron-phonon interactions

On the convergence of step decay step-size for stochastic optimization

学校读者我要写书评

暂无评论

arXiv 2021年

作者： Wang, Xiaoyu Magnússon, Sindri Johansson, Mikael The Division of Decision and Control Systems School of Electrical Engineering and Computer Science KTH Royal Institute of Technology StockholmSE-100 44 Sweden Department of Computer and System Science Stockholm University Stockholm Sweden

The convergence of stochastic gradient descent is highly dependent on the step-size, especially on non-convex problems such as neural network training. Step decay step-size schedules (constant and then cut) are widely used in practice because of their excellent convergence and generalization qualities, but their theoretical properties are not yet well understood. We provide the convergence results for step decay in the non-convex regime, ensuring that the gradient norm vanishes at an (Formula presented) rate. We also provide the convergence guarantees for general (possibly non-smooth) convex problems, ensuring an (Formula presented) convergence rate. Finally, in the strongly convex case, we establish an (Formula presented) rate for smooth problems, which we also prove to be tight, and an (Formula presented) rate without the smoothness assumption. We illustrate the practical efficiency of the step decay step-size in several large scale deep neural network training tasks. Copyright © 2021, The Authors. All rights reserved.

关键词： Deep neural networks