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A novel approach for the prevention of ionizing radiation-induced bone loss using a designer multifunctional cerium oxide nanozyme

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Bioactive Materials 2023年第3期21卷 547-565页

作者： Fei Wei Craig J.Neal Tamil Selvan Sakthivel Yifei Fu Mahmoud Omer Amitava Adhikary Samuel Ward Khoa Minh Ta Samuel Moxon Marco Molinari Jackson Asiatico Michael Kinzel Sergey N.Yarmolenko Vee San Cheong Nina Orlovskaya Ranajay Ghosh Sudipta Seal Melanie Coathup Biionix Cluster Department of Internal MedicineCollege of MedicineUniversity of Central FloridaOrlandoFLUSA Advanced Materials Processing and Analysis Centre Nanoscience Technology Center(NSTC)Materials Science and EngineeringCollege of MedicineUniversity of Central FloridaOrlandoFLUSA CMC Materials 870 North CommonsDrAuroraILUSA Department of Chemistry Oakland UniversityRochesterMIMIUSA School of Applied Sciences Department of Chemical SciencesUniversity of HuddersfieldUK Department of Mechanical and Aerospace Engineering University of Central FloridaOrlandoFLUSA Engineering Research Center for Revolutionizing Biomaterials North Carolina A&T UniversityGreensboroNCUSA Department of Automatic Control and Systems Engineering Insigneo Institute for In Silico MedicineUniversity of SheffieldSheffieldS13JDUK

The disability,mortality and costs due to ionizing radiation(IR)-induced osteoporotic bone fractures are sub-stantial and no effective therapy *** radiation increases cellular oxidative damage,causing an imbalance in bone turnover that is primarily driven via heightened activity of the bone-resorbing *** demonstrate that rats exposed to sublethal levels of IR develop fragile,osteoporotic *** reactive surface sites,cerium ions have the ability to easily undergo redox cycling:drastically adjusting their electronic con-figurations and versatile catalytic *** properties make cerium oxide nanomaterials *** show that an engineered artificial nanozyme composed of cerium oxide,and designed to possess a higher fraction of trivalent(Ce^(3+))surface sites,mitigates the IR-induced loss in bone area,bone architecture,and *** investigations also demonstrate that our nanozyme furnishes several mechanistic avenues of protection and selectively targets highly damaging reactive oxygen species,protecting the rats against IR-induced DNA damage,cellular senescence,and elevated osteoclastic activity in vitro and in ***,we reveal that our nanozyme is a previously unreported key regulator of osteoclast formation derived from macrophages while also directly targeting bone progenitor cells,favoring new bone formation despite its exposure to harmful levels of IR in *** findings open a new approach for the specific prevention of IR-induced bone loss using synthesis-mediated designer multifunctional nanomaterials.

关键词： Ionizing radiation Osteoporosis Nanozyme Cerium oxide Bone strength Bone resorption

Unsupervised Learning-Based Methodology for Detection of Postural Anomalies in Wheelchair Users

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Unsupervised Learning-Based Methodology for Detection of Pos...

IEEE International Conference on systems, Man and Cybernetics

作者： Patrick Vermander Aitziber Mancisidor Giancarlo Fortino Itziar Cabanes Raffaele Gravina Department of Automatic Control and System Engineering University of the Basque Country (UPV/EHU) Bilbao Spain Department of Informatics Modeling Electronics and Systems engineering University of Calabria (UNICAL) Rende Italy

Postural monitoring in wheelchair users is a topic of growing interest. The detection of changes in the sitting patterns of these patients may serve to detect changes in their functional status and be able to adapt rehabilitation early. For this reason, this paper presents a methodology for the detection of specific postural anomalies that, unlike previous works, adopts unsupervised learning. The proposed methodology involves data dimensionality reduction using Principal Component Analysis, and the application of K-means clustering to group different normal posture states. The anomalies are detected using a threshold approach, where data points that fall outside a certain threshold are considered as anomalies. The results show that the methodology is effective in identifying anomalies with a high degree of accuracy (around 90%).

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Out-of-distribution Object Detection through Bayesian Uncertainty Estimation

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arXiv 2023年

作者： Zhang, Tianhao Wang, Shenglin Bouaynaya, Nidhal Calinescu, Radu Mihaylova, Lyudmila Automatic Control and Systems Engineering The University of Sheffield United Kingdom Department of Electrical and Computer Engineering Rowan University United States Department of Computer Science University of York United Kingdom

The superior performance of object detectors is often established under the condition that the test samples are in the same distribution as the training data. However, in many practical applications, out-of-distribution (OOD) instances are inevitable and usually lead to uncertainty in the results. In this paper, we propose a novel, intuitive, and scalable probabilistic object detection method for OOD detection. Unlike other uncertainty-modeling methods that either require huge computational costs to infer the weight distributions or rely on model training through synthetic outlier data, our method is able to distinguish between in-distribution (ID) data and OOD data via weight parameter sampling from proposed Gaussian distributions based on pre-trained networks. We demonstrate that our Bayesian object detector can achieve satisfactory OOD identification performance by reducing the FPR95 score by up to 8.19% and increasing the AUROC score by up to 13.94% when trained on BDD100k and VOC datasets as the ID datasets and evaluated on COCO2017 dataset as the OOD dataset. Copyright © 2023, The Authors. All rights reserved.

关键词： Object detection

Suboptimality analysis of receding horizon quadratic control with unknown linear systems and its applications in learning-based control

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arXiv 2023年

作者： Shi, Shengling Tsiamis, Anastasios De Schutter, Bart Department of Chemical Engineering Massachusetts Institute of Technology United States Delft Center for Systems and Control Delft University of Technology Netherlands Automatic Control Laboratory ETH Zurich Switzerland Delft Center for Systems and Control Delft University of Technology Netherlands

This work analyzes how the trade-off between the modeling error, the terminal value function error, and the prediction horizon affects the performance of a nominal receding-horizon linear quadratic (LQ) controller. By developing a novel perturbation result of the Riccati difference equation, a novel performance upper bound is obtained and suggests that for many cases, the prediction horizon can be either 1 or +∞ to improve the control performance, depending on the relative difference between the modeling error and the terminal value function error. The result also shows that when an infinite horizon is desired, a finite prediction horizon that is larger than the controllability index can be sufficient for achieving a near-optimal performance, revealing a close relation between the prediction horizon and controllability. The obtained suboptimality performance bound is applied to provide novel sample complexity and regret guarantees for nominal receding-horizon LQ controllers in a learning-based setting. We show that an adaptive prediction horizon that increases as a logarithmic function of time is beneficial for regret minimization. Copyright © 2023, The Authors. All rights reserved.

关键词： controllability

Discrete-Analog Filters on Switchable Capacitors with a Summator of Input and Output Signals on a Differential Difference Operational Amplifier

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Discrete-Analog Filters on Switchable Capacitors with a Summ...

Ural Symposium on Biomedical engineering, Radioelectronics and Information Technology (USBEREIT)

作者： Darya Denisenko Alexey Titov Nikolay Prokopenko Nikolay Butyrlagin Department of Scientific Research Don State Technical University Rostov-on-Don Russia Department of Automatic Control Systems Southern Federal University Rostov-on-Don Russia Department of Information Systems and Radio Engineering Don State Technical University Rostov-on-Don Russia

ISBN: (数字)9798350362893

ISBN: (纸本)9798350362909

Four new modifications of discrete analog filters (DAF) of second order low frequencies (LPF) on switched capacitors, which are protected by the authors of the article as objects of intellectual property, have been developed and studied. In the considered DAF family, unlike other known circuit solutions, summation of input and output signals is provided using a differential difference operational amplifier. As a result, the low-pass filter transmission coefficient in the passband does not depend on the passive elements of the circuit and is always equal to minus one. Buffer amplifiers in two DAF circuits are necessary to reduce the influence of switching circuits on transient processes. In the Micro-Cap environment, computer simulations of four modifications of DAFs were performed, showing that the proposed DAFs have the amplitude-frequency response of a low-pass filter. Sequences of pulses are given that should control four electronic keys, made, for example, on CMOS transistors. Graphs of transient processes of the DAF are shown for an input sinusoidal signal with an amplitude of 1V and a frequency of 1591 Hz, equal to the pole frequency at a switching frequency of electronic keys of 1 MHz. The DAF transmission coefficients for the input sinusoidal signal in different frequency ranges are determined. It has been established that with the selected parameters of the elements in the considered DAFs, which are low-pass filters, the input signal at a frequency of 159.10 kHz is attenuated by more than 60 dB.

关键词： Operational amplifiers Switching frequency Capacitors Low-pass filters Switches Radiofrequency integrated circuits Passband

Discrete-Time Stress Matrix-Based Formation control of General Linear Multi-Agent systems

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arXiv 2024年

作者： Onuoha, Okechi Kurawa, Suleiman Tang, Zezhi Dong, Yi School of Computing Engineering and Intelligent Systems Ulster University United Kingdom School of Electrical and Electronic Engineering The University of Manchester United Kingdom Department of Automatic Control and Systems Engineering University of Sheffield United Kingdom School of Electronics & Computer Science University of Southampton United Kingdom

This paper considers the distributed leader-follower stress-matrix-based affine formation control problem of discrete-time linear multi-agent systems with static and dynamic leaders. In leader-follower multi-agent formation control, the aim is to drive a set of agents comprising leaders and followers to form any desired geometric pattern and simultaneously execute any required manoeuvre by controlling only a few agents denoted as leaders. Existing works in literature are mostly limited to the cases where the agents’ inter-agent communications are either in the continuous-time settings or the sampled-data cases where the leaders are constrained to constant (or zero) velocities or accelerations. Here, we relax these constraints and study the discrete-time cases where the leaders can have stationary or time-varying velocities. We propose control laws in the study of different situations and provide some sufficient conditions to guarantee the overall system stability. Simulation study is used to demonstrate the efficacy of our proposed control laws. © 2024, CC BY.

关键词： Linear systems

System Identification Beyond the Nyquist Frequency: A Kernel-Regularized Approach

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arXiv 2025年

作者： van Haren, Max Smith, Roy S. Oomen, Tom Department of Mechanical Engineering Control Systems Technology Section Eindhoven University of Technology Groene Loper 5 Eindhoven5612 AE Netherlands Automatic Control Laboratory ETH Zürich Zürich8092 Switzerland Delft Center for Systems and Control Delft University of Technology Mekelweg 2 Delft2628 CN Netherlands

Models that contain intersample behavior are important for control design of systems with slow-rate outputs. The aim of this paper is to develop a system identification technique for fast-rate models of systems where only slow-rate output measurements are available, e.g., vision-in-the-loop systems. In this paper, the intersample response is estimated by identifying fast-rate models through least-squares criteria, and the limitations of these models are determined. In addition, a method is developed that surpasses these limitations and is capable of estimating unique fast-rate models of arbitrary order by regularizing the least-squares estimate. The developed method utilizes fast-rate inputs and slow-rate outputs and identifies fast-rate models accurately in a single identification experiment. Finally, both simulation and experimental validation on a prototype wafer stage demonstrate the effectiveness of the framework. © 2025, CC BY-NC-ND.

关键词： Decentralized systems

Starting System of Induction Motor with Dynamic Torque control Powered by an Autonomous Sources of Energy Supply

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Starting System of Induction Motor with Dynamic Torque Contr...

International Conference on Modern Electrical and Energy systems (MEES)

作者： Iurii Zachepa Nataliia Zachepa Mykola Antonov Andrii Pyrozhok Department of Systems of Automatic Control and Electric Drive Kremenchuk Mykhailo Ostrohradskyi National University Kremenchuk Ukraine Electrical Engineering Department National University Zaporizhzhya Polytechnic Zaporizhzhya Ukraine

ISBN: (纸本)9798350346848

The paper considers the application of starting systems for induction motors powered by autonomous sources of limited power. The conditions for the formation of the starting torque of an induction motor with the formation of the required transient characteristics and the control of electromagnetic transient moments under conditions of power supply from a stationary network and an autonomous sources of energy supply of limited power are analyzed. Studies have been carried out on the implementation of the “favorable” switching on mode of a three-phase induction motor powered by an autonomous generator according to the principle of creating non-zero initial conditions. An implementation algorithm has been developed and a technical solution has been proposed for the implementation of a starting device with the implementation of a “quasi-favorable” method for switching on an induction motor under conditions of power supply from autonomous sources of energy supply.

关键词： Induction motors Torque Power supplies Heuristic algorithms Torque control Switches Generators

Joint Sensor Scheduling and Target Tracking with Efficient Bayesian Optimisation

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Joint Sensor Scheduling and Target Tracking with Efficient B...

Sensor Signal Processing for Defence (SSPD)

作者： Xingchi Liu Chenyi Lyu Seyed Ahmad Soleymani Wenwu Wang Lyudmila Mihaylova Department of Automatic Control and Systems Engineering University of Sheffield Sheffield UK Centre for Vision Speech and Signal Processing (CVSSP) University of Surrey Guildford UK

The received signal strength measurement has been widely used in search and tracking applications and its benefit is linked with the distance between the transmitter and receiver. This paper proposes an online Bayesian optimisation-based approach that relies on signal strength measurements to schedule multiple sensors for searching and tracking a moving target, without any prior knowledge of the target’s state or motion model. A unique contribution lies in incorporating the Gaussian processes factorisation method into the Bayesian optimisation framework, which enhances the effectiveness of the proposed approach. Numerical results obtained from different sizes of measurements demonstrate that the proposed approach can efficiently schedule two unmanned aerial vehicles. Particularly, it achieves at most 21% lower computational time for deciding measurement locations and 79% lower time for updating the surrogate model as compared to the benchmark approach.

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