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Risk-Informed Model-Free Safe Control of Linear Parameter-Varying Systems

IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 1918-1932页

作者： Babak Esmaeili Hamidreza Modares department of mechanical engineering Michigan State UniversityEast LansingMI 48863 USA

This paper presents a risk-informed data-driven safe control design approach for a class of stochastic uncertain nonlinear discrete-time *** nonlinear system is modeled using linear parameter-varying(LPV)systems.A model-based probabilistic safe controller is first designed to guarantee probabilisticλ-contractivity(i.e.,stability and invariance)of the LPV system with respect to a given polyhedral safe *** obviate the requirement of knowing the LPV system model and to bypass identifying its open-loop model,its closed-loop data-based representation is provided in terms of state and scheduling data as well as a decision *** is shown that the variance of the closedloop system,as well as the probability of safety satisfaction,depends on the decision variable and the noise covariance.A minimum-variance direct data-driven gain-scheduling safe control design approach is presented next by designing the decision variable such that all possible closed-loop system realizations satisfy safety with the highest confidence *** minimum-variance approach is a control-oriented learning method since it minimizes the variance of the state of the closed-loop system with respect to the safe set,and thus minimizes the risk of safety *** the certainty-equivalent approach that results in a risk-neutral control design,the minimum-variance method leads to a risk-averse control *** is shown that the presented direct risk-averse learning approach requires weaker data richness conditions than existing indirect learning methods based on system identification and can lead to a lower risk of safety *** simulation examples along with an experimental validation on an autonomous vehicle are provided to show the effectiveness of the presented approach.

关键词： Data-driven control linear parameter-varying systems probabilistic control safe control

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Event-triggered sliding mode control of linear repetitive processes and its application in metal rolling process

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Science China(Information Sciences) 2024年第3期67卷 167-181页

作者： Xinyu LV Yugang NIU James LAM Key Laboratory of Smart Manufacturing in Energy Chemical Process (east China university of Science and Technology) Ministry of Education department of mechanical engineering The University of Hong Kong

This paper investigates the design problem of a sliding mode controller for linear repetitive processes(LRPs) with a finite pass length on each pass. Under limited communication resources, an eventtriggered mechanism is implemented from the sensors to the controller, whose triggered sequence is consistent with the evolution direction of LRPs. To periodically orchestrate communication between the controller and actuator, a round-robin scheduling mechanism is established based on the pass length. A sliding function involving the state and pass profile is constructed, and the sliding mode controller is designed using triggered states and pass profile signals. Feasible controller gains are attained to ensure the stability of the resultant closed-loop system. Finally, the proposed strategy is implemented for a multi-roll metal rolling process.

关键词： event-triggered mechanism linear repetitive processes metal rolling process round-robin scheduling sliding mode control

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Assessment of scale interactions associated with wake meandering using bispectral analysis methodologies

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Theoretical & Applied Mechanics Letters 2024年第2期14卷 65-75页

作者： Dinesh Kumar Kinjangi Daniel Foti department of mechanical engineering University of MemphisMemphisTennesseeUSA

Large atmospheric boundary layer fluctuations and smaller turbine-scale vorticity dynamics are separately hypothesized to initiate the wind turbine wake meandering phenomenon,a coherent,dynamic,turbine-scale oscillation of the far *** interactions,the mechanism of energy transfers between scales,manifest as triples of wavenumbers or frequencies and can be characterized through bispectral *** bispectrum,which correlates the two frequencies to their sum,is calculated by two recently developed multi-dimensional modal decomposition methods:scale-specific energy transfer method and bispectral mode ***-eddy simulation of a utility-scale wind turbine in an atmospheric boundary layer with a broad range of large length-scales is used to acquire instantaneous velocity *** bispectrum from both methods identifies prominent upwind and wake meandering interactions that create a broad range of energy scales including the wake meandering *** coherent kinetic energy associated with the interactions shows strong correlation between upwind scales and wake meandering.

关键词： Wind turbine wake Mode decomposition Bispectral analysis

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Supposition of graphene stacks to estimate the contact resistance and conductivity of nanocomposites

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 663-676页

作者： Y.ZARE M.T.MUNIR G.J.WENG K.Y.RHEE Biomaterials and Tissue engineering Research Group Department of Interdisciplinary TechnologiesBreast Cancer Research CenterMotamed Cancer InstituteTehran ***Iran College of engineering and Technology American University of the Middle EastEgaila 54200Kuwait department of mechanical and Aerospace engineering Rutgers UniversityNew BrunswickNJ 08903U.S.A. department of mechanical engineering(BK21 Four) College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equations superior to those previously *** contact resistance and nanocomposite conductivity are modeled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact *** developed model's accuracy is verified through numerous experimental *** further validate the models and establish correlations between parameters,the effects of all the variables on contact resistance and nanocomposite conductivity are ***,the contact resistance is primarily dependent on the polymer tunnel resistivity,contact area,and tunneling *** dimensions of the graphene nanosheets significantly influence the conductivity,which ranges from 0 S/m to90 S/*** increased number of nanosheets in stacks and a larger gap between them enhance the nanocomposite's ***,the thicker interphase and smaller tunneling size can lead to higher sample conductivity due to their optimistic effects on the percolation threshold and network efficacy.

关键词： graphene polymer composite stacked nanosheet tunneling conductivity contact resistance interphase

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Defect Detection Model Using Time Series Data Augmentation and Transformation

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Computers, Materials & Continua 2024年第2期78卷 1713-1730页

作者： Gyu-Il Kim Hyun Yoo Han-Jin Cho Kyungyong Chung department of Computer Science Kyonggi UniversitySuwon-si16227Korea Contents Convergence Software Research Institue Kyonggi UniversitySuwon-si16227Korea department of Energy IT engineering Far East UniversityEumsung-gun27601Korea Division of AI Computer Science and engineering Kyonggi UniversitySuwon-si16227Korea

Time-series data provide important information in many fields,and their processing and analysis have been the focus of much ***,detecting anomalies is very difficult due to data imbalance,temporal dependence,and ***,methodologies for data augmentation and conversion of time series data into images for analysis have been *** paper proposes a fault detection model that uses time series data augmentation and transformation to address the problems of data imbalance,temporal dependence,and robustness to *** method of data augmentation is set as the addition of *** involves adding Gaussian noise,with the noise level set to 0.002,to maximize the generalization performance of the *** addition,we use the Markov Transition Field(MTF)method to effectively visualize the dynamic transitions of the data while converting the time series data into *** enables the identification of patterns in time series data and assists in capturing the sequential dependencies of the *** anomaly detection,the PatchCore model is applied to show excellent performance,and the detected anomaly areas are represented as heat *** allows for the detection of anomalies,and by applying an anomaly map to the original image,it is possible to capture the areas where anomalies *** performance evaluation shows that both F1-score and Accuracy are high when time series data is converted to ***,when processed as images rather than as time series data,there was a significant reduction in both the size of the data and the training *** proposed method can provide an important springboard for research in the field of anomaly detection using time series ***,it helps solve problems such as analyzing complex patterns in data lightweight.

关键词： Defect detection time series deep learning data augmentation data transformation

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Negative Poisson’s ratio locally resonant seismic metamaterials vibration isolation barrier

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Acta Mechanica Sinica 2024年第8期40卷 239-252页

作者： Haibin Ding Nianyong Huang Muhammad Changjie Xu Lihong Tonog State Key Laboratory of Performance Monitoring and Protecting of Rail Transit Infrastructure Nanchang330013China Institute of Geotechnical engineering School of Civil Engineering and ArchitectureEast China Jiaotong UniversityNanchang330013China department of mechanical Manufacturing and Biomedical EngineeringTrinity College DublinDublinD02PN40Ireland department of mechanical engineering University of GalwayUniversity RoadGalwayH91 HX31Ireland

In recent decades,the application of seismic metamaterials to protect civil infrastructures being free of the damage of earthquakes has been attracting extensive ***,the proposed locally resonant seismic metamaterials provide the probability of isolating the low-frequency seismic wave using a small-size isolation ***,in previous studies,the energy absorption properties of locally resonant seismic metamaterials remain one of the least understood aspects of *** from the fascinating energy absorption characteristic of negative Poisson ratio(NPR)metamaterial,we creatively design a new seismic metamaterial structure by assembling the locally resonant seismic metamaterial and NPR metamaterial,to isolate seismic *** sound cone technique combining the transmission spectrum is employed to identify the surface wave from the hybrid *** generation mechanism of frequency bandgap and the isolation effectiveness of the proposed seismic metamaterial are discussed in *** results indicate that the generation of ultra-low and ultra-wide frequency bandgap with the range of 0.65 Hz–18.9 Hz is attributed to the locally resonant and energy absorption of the proposed seismic metamaterial structure and the excellent isolation effect is achieved by transforming the surface wave into the bulk *** frequency bandgap narrows as the distance increases between each *** addition,the mechanical properties of the NPR bearing,such as the Poisson ratio,mass density,and elastic modulus,have remarkable impact on the frequency bandgap,especially on the upper bound *** practical engineering,the NPR bearing with a low Poisson ratio,small mass density,and high elastic modulus is suggested for the design of the NPR locally resonant seismic metamaterial *** domain analysis for the practical seismic wave verifies that the proposed seismic metamaterial has a promising application in isolating ultra-low and ultra-wi

关键词： Seismic metamaterials Locally resonant Negative Poisson ratio(NPR) Seismic waves Frequency bandgap Vibration isolation barrier

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Micro/nano flow chemistry by Beyond Limits Manufacturing

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Chinese Chemical Letters 2024年第5期35卷 3-12页

作者： Peiwen Liu Fang Zhao Jing Zhang Yunpeng Bai Jinxing Ye Bo Bao Xinggui Zhou Li Zhang Changlu Zhou Xinhai Yu Peng Zuo Jianye Xia Lian Cen Yangyang Yang Guoyue Shi Lin Xu Weiping Zhu Yufang Xu Xuhong Qian State Key Laboratory of Bioreactor engineering Shanghai Key Laboratory of Chemical BiologySchool of PharmacyEast China University of Science and TechnologyShanghai 200237China State Key Laboratory of Chemical engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China State Key Laboratory of Bioreactor engineering Shanghai Collaborative Innovation Center for BiomanufacturingEast China University of Science and TechnologyShanghai 200237China School of Biomedical and Pharmaceutical Sciences Guangdong University of TechnologyGuangzhou 510006China School of mechanical and Power engineering East China University of Science and TechnologyShanghai 200237China Shanghai Key Laboratory of Green Chemistry and Chemical Processes Department of ChemistrySchool of Chemistry and Molecular EngineeringEast China Normal UniversityShanghai 200241China

In September 2018,we proposed the cutting-edge concept of“Beyond Limits Manufacturing”(BLM).BLM technology is based on the three-dimensional inner engraving or precise outer engraving of ultra-fast laser,to invent micro/nano scale flow chips or devices,which makes it possible for the microform,integration,economy,safety,high efficiency,green and intelligence of research,development and manufacturing process,so as to realize transformational manufacturing in the era of Industry *** this paper,we reviewed the representative results we made in the field of micro/nano flow chemistry during the implementation of the BLM major project(December 2019 to August 2023),and discussed its application prospects in micro/nano flow chemistry.

关键词： Beyond Limits Manufacturing Flow chemistry Pharmaceutical manufacturing Microreactor

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Performance analysis of a photovoltaic/thermal system with lunar regolith-based thermal storage for the lunar base

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Science China(Technological Sciences) 2024年第4期67卷 1113-1123页

作者： SUN WenGan ZHAO Bin PEI Yu SHI LingFeng HU MaoBin LI MuJun REN Xiao PEI Gang Deep Space Exploration Laboratory Hefei 230026China department of Thermal Science and Energy engineering University of Science and Technology of ChinaHefei 230026China department of mechanical and Aerospace engineering University of California San DiegoLa JollaCA 92093USA department of Precision Machinery and Precision Instrumentation University of Science and Technology of ChinaHefei 230026China College of New Energy China University of Petroleum(East China)Qingdao 266000China

Powering a moon base,especially keeping it warm during the long lunar night,is a big *** paper introduces a photovoltaic/thermal(PV/T)system incorporating regolith thermal storage to solve the challenge of power and heat provision for the lunar base *** vacuum of space around the moon helps this system by reducing heat *** the moon's daytime,the system not only generates electricity but also captures *** stored heat in the regolith is then used at night,reducing the amount of equipment we need to send from *** spectrally selective PV/T panels are designed to absorb a wide range of sunlight(0.3–2.5μm)while minimizing heat loss in the infrared range(3–30μm).Simulation results of the hybrid solar energy system indicate the average value of the overall efficiency is 45.9%,which relatively elevates 56.1%compared to the PV *** launch mass of the proposed PV/T system is only 8.4%of a traditional photovoltaic-lithium battery system with the same amount of energy *** the total specific energy of the proposed system is 7.3 kWh kg^(-1),while that of the photovoltaic-lithium battery system is about 0.3 kWh kg^(-1).In summary,this study proposes an alternative combined heat and electricity supply system for the lunar base,which can greatly reduce the launch mass and free up load for other scientific research equipment.

关键词： in-situ resource utilization(IRSU) regolith thermal storage photovoltaic/thermal(PV/T) spectral selectivity

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Effects of the nozzle structure and fluidized gas composition on the gas-particle two-phase jet characteristic in a powder fuel scramjet

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Particuology 2024年第9期92卷 166-179页

作者： Changfei Zhuo Hongming Ding Xiaobin Ren Hanyu Deng Xiong Chen School of mechanical and engineering Key Laboratory of Special Engine TechnologyMinistry of EducationNanjing University of Science and TechnologyNanjing210094China department of mechanical engineering National University of Singapore9 Engineering Drive 1Singapore117576 Shanxi North Xing'an Chemical Industry Co. Ltd.Taiyuan030008China

The interaction between nozzle design and fluidization gas composition significantly influences the dynamics within a powder fuel scramjet's combustion *** investigate this relationship,an experimental study utilized high-speed shadow imaging technology to explore the macroscopic aspects of powder fuel *** investigation examined various convergence angles,nozzle throat lengths,and fluidized gas *** findings include:During jet development,powder fuel initially concentrates near the axis,with non-convergence angle nozzles exhibiting longer concentrated distribution periods than convergence angle *** nozzle convergence angles lead to increased penetration distance,frontal velocity,and radial diffusion distance during the initial stages of jet ***,stable jet shapes show larger divergence angles as nozzle convergence angle decreases,with the largest divergence angle observed atα=60°.In the initial 0-7 ms of jet development,the powder fuel jet demonstrates greater penetration distance and frontal velocity under certain ***,penetration distance and frontal velocity increase with throat length from 7 to 20 ms,accompanied by changes in divergence ***,at a throat length(l)of 2 mm,the near-field divergence angle measures 46.50°,and the far-field divergence angle is 22.25°.Conversely,at l=8mm,the near-field divergence angle is 33.49°,and the far-field divergence angle is 23.21°.The fluidization gas composition minimally affects jet penetration distance and frontal velocity during the initial 0-3 ***,due to hydrogen's low density,hydrogen/powder fuel jets exhibit shorter distances and velocities compared to nitrogen/powder fuel *** fluidization also results in larger divergence angles,particularly in the near *** findings underscore the importance of nozzle design and fluidization gas composition in optimizing scramjet performance and efficiency.

关键词： Multiphase flows Gas-particle two-phase jet Nozzle contraction angle Powder fuel scramjet

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Covalent Bond Based Android Malware Detection Using Permission and System Call Pairs

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Computers, Materials & Continua 2024年第3期78卷 4283-4301页

作者： Rahul Gupta Kapil Sharma R.K.Garg department of Information Technology Delhi Technological UniversityNew Delhi110042India department of mechanical engineering Deenbandhu Chhotu Ram University of Science and TechnologyMurthal131039India

The prevalence of smartphones is deeply embedded in modern society,impacting various aspects of our *** versatility and functionalities have fundamentally changed how we communicate,work,seek entertainment,and access *** the many smartphones available,those operating on the Android platform dominate,being the most widely used *** widespread adoption of the Android OS has significantly contributed to increased malware attacks targeting the Android ecosystem in recent ***,there is an urgent need to develop new methods for detecting Android *** literature contains numerous works related to Android malware *** far as our understanding extends,we are the first ones to identify dangerous combinations of permissions and system calls to uncover malicious behavior in Android *** introduce a novel methodology that pairs permissions and system calls to distinguish between benign and malicious *** approach combines the advantages of static and dynamic analysis,offering a more comprehensive understanding of an application’s *** establish covalent bonds between permissions and system calls to assess their combined *** introduce a novel technique to determine these pairs’Covalent Bond Strength *** pair is assigned two scores,one for malicious behavior and another for benign *** scores serve as the basis for classifying applications as benign or *** correlating permissions with system calls,the study enables a detailed examination of how an app utilizes its requested permissions,aiding in differentiating legitimate and potentially harmful *** comprehensive analysis provides a robust framework for Android malware detection,marking a significant contribution to the *** results of our experiments demonstrate a remarkable overall accuracy of 97.5%,surpassing various state-of-the-art detection techniques proposed in the current literature.

关键词： Android malware android security hybrid analysis permission and system call pairs

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