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Eigenvalue Problems Arising in the Control of a Distributed Parameter Bioreactor

IFAC Proceedings Volumes 1995年第8期28卷 509-514页

作者： M.T. Nihtilä J.P. Babary University of Kuopio Faculty of Natural and Environmental Sciences Department of Computer Science and Applied Mathematics P.O.Box 1627 FIN-702ll Kuopio FINLAND. Centre National de la Recherche Scientifique Laboratoire d'Analyse et d'Architecture des Systèmes 7 avenue du Colonel Roche F-3l077 Toulouse Cédex FRANCE

L'objet de cette communication concerne l'33;tude d'un mod32;le à param32;tres r33;partis d'un bior33;acteur à lit fixe fonctionnant en mode continu. L'accent est port33... 详细信息

L'objet de cette communication concerne l'étude d'un modèle à paramètres répartis d'un bioréacteur à lit fixe fonctionnant en mode continu. L'accent est porté sur une propriété stracturelle du modèle du procédé fomulé sous la forme d'un système aux dérivées partielles. Dans le cas de systèmes à paramètres localisés, cette propriété, relative à un déphasage non-minimal, est à l'origine de certaines difficultés dans la conception de lois de commande. Dans le cas d'un modèle à paramètres répartis, la loi de commande est obtenue après semidiscrétisation. La seule variable d'espace de ce modèle est discrétisée à l'aide de la mèthode des éléments finis de Galerkin. Pour certaines valeurs paramétriques du modèle aux dérivées partielles, la commande linéarisante du modèle semi-discrétisé engendre un comportement instable dans le sens où la dynamique des zéros du système est instable. Ce comportement instable avait déjà été observé quand la discrétisation est effectuée à l'aide de la mèthode de collocation orthogonale. Les relations existant entre la position des zéros du modèle aux dérivées partielles linéarisé autour de sa solution en régime permanent et les propriétés de stabilité/instabilité de la commande linéarisante du modèle semi-discrétisé sont discutées de façon analogue au cas des systèmes à paramètres localisés. A distributed parameter model of a continuous flow fixed-bed reactor is studied. The main emphasis lies on a structural property of the partial differential equation (POE) system model. This property, which in lumped parameter systems, is called nonminimum phase property has certain implications in the controller design. The controller design for the PDE model is constructed via semidiscretisation. The only space variable of the PDE model is discretised by using Galerkin's finite element method (FEM). For some parameter values of the POE model the linearising control of the semidiscretised model resulted in unstable behaviour in the sense that the zero dy

关键词： Systèmes à paramètres répartis Approximation par collocation orthogonale Approximation aux éléments finis Commande linéarisante Déphasage non-minimal Dynamique des zéros Fonction de transfert linéarisée Distributed parameter systems Orthogonal collocation approximation Finite element method approximation Linearizing control Nonmimimum phase property Zero dynamics Linearized transfer function

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Dynamic collapse analysis of four-story steel frame using E-Simulator

Dynamic collapse analysis of four-story steel frame using E-...

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4th International Conference on Computational Methods in Structural Dynamics and Earthquake Engineering, COMPDYN 2013

作者： Miyamura, Tomoshi Ohsaki, Makoto Yamashita, Takuzo Isobe, Daigoro Kohiyama, Masayuki Department of Computer Science College of Engineering Nihon University 1 Nakagawara Tokusada Tamura Koriyama 963-8642 Japan Department of Architecture Hiroshima University 1-4-1 Kagamiyama Higashi-Hiroshima 739-8527 Japan Hyogo Earthquake Eng. Res. Center National Res. Inst. for Earth Science and Disaster Prevention 1501-21 Nishikameyama Mitsuta Shijimi Miki 673-0515 Japan Division of Engineering Mechanics and Energy University of Tsukuba 1-1-1 Tennodai Tsukuba-shi Ibaraki 305-8573 Japan Department of System Design Engineering Keio University 3-14-1 Hiyoshi Kohoku Yokohama 223-8522 Japan

ISBN: (纸本)9789609999427

Dynamic collapse analyses of a 4-story steel building frame modeled by solid elements are performed using the E-Simulator, which is a parallel finite element analysis software package for civil and building structures. Code verification, calculation verification, and validation of the numerical codes (V&V) are conducted by comparing the results obtained by the E-Simulator, those obtained by a beam element analysis code, and the experimental results obtained by the 3-D full-scale earthquake testing facility, the E-Defense at NIED. The seismic response analyses under 60% or 100% of the JR Takatori seismic wave of the 1995 Hyogoken-Nanbu earthquake are performed. The shear forces and interstory drift angles of the 1st story obtained by the E-Simulator simulation and the E-Defense full-scale test have good agreement. Both response of the whole frame and local deformation due to plastic buckling are simulated in the analysis using the E-Simulator.

关键词： Finite element method

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Lyapunov theorems with semidefinite functions

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IFAC Proceedings Volumes 1999年第2期32卷 1802-1807页

作者： Abderrahman Iggidr Boris Kalitine Gauthier Sallet CONGE Project INRIA Lorraine & UPRES A 7035 Dept. of Mathematics University of Metz I.S.C.M.P. Bat. A Ile da Saulcy 57045 Metz cedex 01 France. phone: +33 3 87 54 72 80 Fax: +33 3 87 54 72 77 Belarusian State University Faculty of Applied Mathematics & Computer Science Chair of Optimal Control Methods 220050 Republic Belarus Minsk Fr. Skartny av. 4

This paper gives a new generalization of Lyapunov theorems. Tt shows how to explore the stability properties of a given system by using a Lyapunov function which is nonnegative semidefinite, rather than positive definite. Several examples and an application to the algebraic Riccati Equation are given to illustrate the new approach.

关键词： Lyapunov functions nonlinear systems stability semidefinite functions Riccati equations

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Free weight exercises recognition based on dynamic time Warping of acceleration data

Communications in Computer and Information Science

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Communications in computer and Information science 2013年 355卷 178-185页

作者： Li, Chuanjiang Fei, Minrui Hu, Huosheng Qi, Ziming School of Mechanical Engineering and Automation Shanghai Key Laboratory of Power Station Automation Technology Shanghai University 200072 China College of Information Mechanical and Electrical Engineering Shanghai Normal University Shanghai 200234 China Department of Computer Science University of ESSEX Colchester CO4 3SQ United Kingdom School of Architecture Building and Eng. Otago Polytechnic Dunedin 9054 New Zealand

To maximize training effects in free weight exercises, people need to remember repetitions of each type of exercises, which is tedious and difficult. Recognizing exercises type and counting automatically can overcome this problem, and multiple accelerometers were used in the existing exercises recognition. This paper presents a new recognition method based on one triaxial accelerometer, in which a filtered acceleration data stream is divided into time series with unequal length for peak analysis instead of conventional fixed length window. Based on this time series, Dynamic Time Warping (DTW) is deployed to recognize weight exercise types. 3D Euclidean distance and Itakura parallelogram constraint region are used to improve recognition performance. A reference template is set up for each class based on many examples instead of one in the conventional way. The proposed procedures are compared with other popular methods with both the user-dependent protocol and the userindependent protocol. Results show that proposed approach is feasible and can achieve good performance. © Springer-Verlag Berlin Heidelberg 2013.

关键词： Accelerometers

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A Combined Solution of the Inverse Kinematic Task in the Vicinity of the Singularities

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Journal of Advanced Computational Intelligence and Intelligent Informatics 2004年第5期8卷 514-522页

作者： Rudas, Imre J. Tar, József K. Bitó, János F. Szeghegyi, Ágnes Kozlowski, Krzysztof R. John von Neumann Faculty of Informatics Budapest Polytechnic Népszínház u. 8 BudapestH-1081 Hungary Károly Keleti Faculty of Economics Budapest Polytechnic Népszínház u. 8 BudapestH-1081 Hungary Chair of Control Robotics and Computer Science Poznan University of Technology ´ Ul. Piotrowo 3a Poznan60-965 Poland

In the case of the traditional differential approach of solving the inverse kinematic task, depending on the desired trajectory that may approach, reach, and cross the boundaries of non-singular domains or domains of different degree of singularity, certain joint velocities may take huge values. Within the singularity it may happen that the desired task cannot exactly be solved, and that this imprecise solution has one or more degree of freedom in its ambiguity. The motion planner provided with end-point position and orientation data with respect to the workshop’s Cartesian frame does not have satisfactory information for locally resolving ambiguity. The rather modern approaches follow global way of thinking and apply Genetic Algorithms or similar evolutionary methods requiring huge computational power. The here presented approach is a compromise between these essentially different cases. For non-singular points it applies a fast algorithm to the differential solution, while near and in the singularities the Complex Algorithm combining the primary (that is tracking the prescribed data as precisely as possible) and secondary (complementary aspects applied in ambiguity resolution) requirements in an efficient way. The method is illustrated by calculations for particular trajectories in the case of a 6 DOF robot arm. © Fuji Technology Press Ltd. Creative Commons CC BY-ND: This is an Open Access article distributed under the terms of the Creative Commons Attribution-NoDerivatives 4.0 International License (http://***/licenses/by-nd/4.0/).

关键词： Inverse kinematics

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A Multi-Player Potential Game Approach for Sensor Network Localization with Noisy Measurements 63

A Multi-Player Potential Game Approach for Sensor Network Lo...

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63rd IEEE Conference on Decision and Control, CDC 2024

作者： Xu, Gehui Chen, Guanpu Fidan, Baris Hong, Yiguang Qi, Hongsheng Parisini, Thomas Johansson, Karl H. Kth Royal Institute of Technology Division of Decision and Control Systems School of Electrical Engineering and Computer Science Stockholm100 44 Sweden University of Waterloo Department of Mechanical and Mechatronics Engineering WaterlooONN2L 3G1 Canada Tongji University Department of Control Science and Engineering shanghai201804 China Shanghai Research Institute for Intelligent Autonomous Systems Shanghai201210 China Key Laboratory of Systems and Control Academy of Mathematics and Systems Science Beijing China University of Chinese Academy of Sciences School of Mathematical Sciences Beijing China Aalborg University Department of Electronic Systems Denmark Imperial College London Department of Electrical and Electronic Engineering LondonSW7 2AZ United Kingdom University of Trieste Department of Engineering and Architecture Italy

ISBN: (纸本)9798350316339

Sensor network localization (SNL) is a challenging problem due to its inherent non-convexity and the effects of noise in inter-node ranging measurements and anchor node position. We formulate a non-convex SNL problem as a multiplayer non-convex potential game and investigate the existence and uniqueness of a Nash equilibrium (NE) in both the ideal setting without measurement noise and the practical setting with measurement noise. We first show that the NE exists and is unique in the noiseless case, and corresponds to the precise network localization. Then, we study the SNL for the case with errors affecting the anchor node position and the inter-node distance measurements. Specifically, we establish that in case these errors are sufficiently small, the NE exists and is unique. It is shown that the NE is an approximate solution to the SNL problem, and that the position errors can be quantified accordingly. Based on these findings, we apply the results to case studies involving only inter-node distance measurement errors and only anchor position information inaccuracies. © 2024 IEEE.

关键词： Nash equilibrium

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Deep Reinforcement Learning Based Collision Avoidance System for Autonomous Ships

SSRN

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SSRN 2023年

作者： Wang, Yong Xu, Haixiang Feng, Hui He, Jianhua Yang, Haojie Yang, Lian School of Naval Architecture Ocean and Energy Power Engineering Wuhan University of Technology Wuhan430063 China Key Laboratory of High Performance Ship Technology Wuhan University of Technology Ministry of Education Wuhan430063 China School of Computer Science and Electronic Engineering University of Essex CO4 3SQ United Kingdom Zhuhai519000 China

Autonomous ships is a key to avoid accidents caused by human errors and improve maritime safety. However, unlike the autonomous vehicles counterpart, collision avoidance for autonomous ships faces many challenges due to the hash driving environments, difficult ship control and large stopping distance. In this paper, we investigate a collision avoidance system for autonomous ships under complex encounter scenarios, such as busy ports. In the system various sensors are used to detect objects and perceive the maritime environments. To help the autonomous ships handle the complex and dynamic scenarios that may be encountered, a collision map used to describe the ships encounter scenarios is generated and utilized as the input of a deep reinforcement learning (DRL) model. The DRL model is applied to make collision avoidance and safe driving decisions. New reward functions are proposed to train the DRL model to generate safe ship maneuver actions to reduce colllisions and ensure compliance with the Convention on the International Regulations for Preventing Collisions at Sea (COLREGs). Furthermore, a self-adaptive parameters sharing approach is designed for fast convergence and collision avoidance performance of the DRL model. Simulation results show that the proposed system has high DRL convergence speed and excellent collision avoidance. © 2023, The Authors. All rights reserved.

关键词： Collision avoidance

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MobVGG: Ensemble technique for birds and drones prediction

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Heliyon 2024年第21期10卷 e39537页

作者： Muhammad Saqib, Sheikh Mazhar, Tehseen Iqbal, Muhammad Almogren, Ahmad Shahazad, Tariq Rehman, Ateeq Ur Hamam, Habib Department of Computing and Information Technology Gomal University Dera Ismail Khan 29220 Pakistan Department of Computer Science School Education Department Government of Punjab Layyah 31200 Pakistan Chair of Cyber Security Department of Computer Science College of Computer and Information Sciences King Saud University Riyadh 11633 Saudi Arabia Department of Computer Science COMSATS University Islamabad Sahiwal Campus Sahiwal 57000 Pakistan School of Computing Gachon University Seongnam 13120 South Korea Faculty of Engineering Uni de Moncton Moncton E1A3E9 NB Canada School of Electrical Engineering University of Johannesburg Johannesburg 2006 South Africa International Institute of Technology and Management (IITG) Av. Grandes Ecoles Libreville BP 1989 Gabon Bridges for Academic Excellence - Spectrum Tunis Tunisia

Detection of aerial activities, including drones and birds, has practical implications for automating bird surveys and developing radar systems for aerial object collision detection. Convolutional neural networks (CNNs) have been extensively utilized for image recognition and classification tasks, albeit prior research predominantly focuses on single-class 'drone' classification. However, a gap persists in achieving high accuracy for multi-class classification. To address the limitations of traditional CNNs, such as vanishing gradients and the necessity for numerous layers, this study introduces a novel model termed "MobVGG.” This model combines the architectures of MobileNetV2 and VGG16 to accurately classify images as either 'bird' or 'drone'. The dataset comprises 4212 images for each category of 'bird' and 'drone'. The stringent methodology was applied for dataset preparation and model training to ensure the reliability of the findings. Comparative analysis with previous research demonstrates that the proposed MobVGG model, trained on both 'bird' and 'drone' images, achieves superior accuracy (96 %) compared to benchmark studies. Our paper targets researchers and graduate students as its primary audience. © 2024 The Authors

关键词： Convolutional neural networks (CNNs) Deep learning Ensemble technique MobileNetV2 VGG16

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An Empirical Investigation of the Role of Pre-training in Lifelong Learning

arXiv

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arXiv 2021年

作者： Mehta, Sanket Vaibhav Patil, Darshan Chandar, Sarath Strubell, Emma School of Computer Science Carnegie Mellon University PittsburghPA15213 United States Mila Quebec AI Institute Université de Montréal MontrealQCH3T 1J4 Canada Mila Quebec AI Institute Canada CIFAR AI Chair École Polytechnique de Montréal MontrealQCH3T 1J4 Canada

The lifelong learning paradigm in machine learning is an attractive alternative to the more prominent isolated learning scheme not only due to its resemblance to biological learning but also its potential to reduce energy waste by obviating excessive model re-training. A key challenge to this paradigm is the phenomenon of catastrophic forgetting. With the increasing popularity and success of pre-trained models in machine learning, we pose the question: What role does pre-training play in lifelong learning, specifically with respect to catastrophic forgetting? We investigate existing methods in the context of large, pre-trained models and evaluate their performance on a variety of text and image classification tasks, including a large-scale study using a novel data set of 15 diverse NLP tasks. Across all settings, we observe that generic pre-training implicitly alleviates the effects of catastrophic forgetting when learning multiple tasks sequentially compared to randomly initialized models. We then further investigate why pre-training alleviates forgetting in this setting. We study this phenomenon by analyzing the loss landscape, finding that pre-trained weights appear to ease forgetting by leading to wider minima. Based on this insight, we propose jointly optimizing for current task loss and loss basin sharpness to explicitly encourage wider basins during sequential fine-tuning. We show that this optimization approach outperforms several state-of-the-art task-sequential continual learning algorithms across multiple settings, occasionally even without retaining a memory that scales in size with the number of tasks. © 2021, CC BY.

关键词： Machine learning

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Wireless-Friendly Window Position Optimization for RIS-Aided Outdoor-to-Indoor Networks based on Multi-Modal Large Language Model

arXiv

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arXiv 2024年

作者： Hou, Jinbo Qiu, Kehai Zhang, Zitian Yu, Yong Wang, Kezhi Capolongo, Stefano Zhang, Jiliang Li, Zeyang Zhang, Jie The Department of Electronic and Electrical Engineering the University of Sheffield Sheffield United Kingdom The Department of Computer Science and Technology University of Cambridge CambridgeCB3 0FD United Kingdom Brunel University London United Kingdom The School of Information and Electronic Engineering Zhejiang Gongshang University Hangzhou China The Design & Health Lab Department of Architecture Built Environment and Construction Engineering Politecnico di Milano Italy The Department of Computer Science Brunel University London Middlesex UxbridgeUB8 3PH United Kingdom The State Key Laboratory of Synthetical Automation for Process Industries The College of Information Science and Engineering Northeastern University Shenyang China The Centre for Wireless Innovation Queen’s University of Belfast BelfastBT3 9DT United Kingdom

This paper aims to simultaneously optimize indoor wireless and daylight performance by adjusting the positions of windows and the beam directions of window-deployed reconfigurable intelligent surfaces (RISs) for RIS-aided outdoor-to-indoor (O2I) networks utilizing large language models (LLM) as optimizers. Firstly, we illustrate the wireless and daylight system models of RIS-aided O2I networks and formulate a joint optimization problem to enhance both wireless traffic sum rate and daylight illumination performance. Then, we present a multi-modal LLM-based window optimization (LMWO) framework, accompanied by a prompt construction template to optimize the overall performance in a zero-shot fashion, functioning as both an architect and a wireless network planner. Finally, we analyze the optimization performance of the LMWO framework and the impact of the number of windows, room size, number of RIS units, and daylight factor. Numerical results demonstrate that our proposed LMWO framework can achieve outstanding optimization performance in terms of initial performance, convergence speed, final outcomes, and time complexity, compared with classic optimization methods. The building’s wireless performance can be significantly enhanced while ensuring indoor daylight performance. Copyright © 2024, The Authors. All rights reserved.

关键词： Daylighting

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