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Robust Machine Learning Mapping of sEMG Signals to Future Actuator Commands in Biomechatronic Devices

Journal of Bionic Engineering 2024年第1期21卷 270-287页

作者： Ali Nasr Sydney Bell Rachel L.Whittaker Clark R.Dickerson John McPhee Systems Design Engineering University of WaterlooWaterloo N2L 3G1Canada Kinesiology and Health Sciences University of WaterlooWaterloo N2L3G3Canada

A machine learning model for regression of interrupted Surface Electromyography(sEMG)signals to future control-oriented signals(e.g.,robot’s joint angle and assistive torque)of an active biomechatronic device for high-level myoelectric-based hierarchical control is proposed.A Recurrent Neural Network(RNN)was trained using output data,initially obtained from offline optimization of the biomechatronic(human–robot)device and shifted by the prediction horizon.The input of the RNN consisted of interrupted sEMG signals(to mimic signal disconnections)and previous kinematic signals of the assistive system.The RNN with a 0.1-s prediction horizon could predict the control-oriented joint angle and assistive torque with 92%and 86.5%regression accuracy,respectively,for the test dataset.This proposed approach permits a fast,predictive,and direct estimation of control-oriented signals instead of an iterative process that optimizes assistive torque in the inverse dynamic simulation of a multibody human–robot system.Training with these interrupted input signals significantly improves the regression accuracy in the case of sEMG signal disconnection.This Robust Predictive Control-oriented Machine Learning(Robust-MuscleNET)model can support volitional high-level myoelectric-based control of biomechatronic devices,such as exoskeletons,prostheses,and assistive/resistive robots.Future work should study the application to prosthesis control as well as the repeatability of the high-level controller with electrode shift.The low-level hierarchical controller that manages the human–robot interaction,the assistance/resistance strategy,and the actuator coordination should also be studied.

关键词： Myoelectric-based control-Surface electromyography Machine learning Multibody system dynamics Exoskeleton Bionic

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Experimental measurement and numerical modeling of deformation behavior of breast cancer cells passing through constricted microfluidic channels

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Microsystems & Nanoengineering 2024年第1期10卷 129-147页

作者： Pouyan Keshavarz Motamed Hesam Abouali Mahla Poudineh Nima Maftoon Department of Systems Design Engineering University of WaterlooWaterlooON N2L 3G1Canada Center for Bioengineering and Biotechnology University of WaterlooWaterlooON N2L 3G1Canada Department of Electrical and Computer Engineering University of WaterlooWaterlooON N2L 3G1Canada

During the multistep process of metastasis,cancer cells encounter various mechanical forces which make them deform drastically.Developing accurate in-silico models,capable of simulating the interactions between the mechanical forces and highly deformable cancer cells,can pave the way for the development of novel diagnostic and predictive methods for metastatic progression.Spring-network models of cancer cell,empowered by our recently proposed identification approach,promises a versatile numerical tool for developing experimentally validated models that can simulate complex interactions at cellular scale.Using this numerical tool,we presented spring-network models of breast cancer cells that can accurately replicate the experimental data of deformation behavior of the cells flowing in a fluidic domain and passing narrow constrictions comparable to microcapillary.First,using high-speed imaging,we experimentally studied the deformability of breast cancer cell lines with varying metastatic potential(MCF-7(less invasive),SKBR-3(medium-high invasive),and MDA-MB-231(highly invasive)in terms of their entry time to a constricted microfluidic channel.We observed that MDA-MB-231,that has the highest metastatic potential,is the most deformable cell among the three.Then,by focusing on this cell line,experimental measurements were expanded to two more constricted microchannel dimensions.The experimental deformability data in three constricted microchannel sizes for various cell sizes,enabled accurate identification of the unknown parameters of the spring-network model of the breast cancer cell line(MDA-MB-231).Our results show that the identifed parameters depend on the cell size,suggesting the need for a systematic procedure for identifying the size-dependent parameters of spring-network models of cells.As the numerical results show,the presented cell models can simulate the entry process of the cell into constricted channels with very good agreements with the measured experimental data.

关键词： strict passing numerical

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Improved State-space Modelling for Microgrids Without Virtual Resistances

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Journal of Modern Power Systems and Clean Energy 2024年第2期12卷 584-596页

作者： Paranagamage S.A.Peiris Shaahin Filizadeh Dharshana Muthumuni Department of Electrical and Computer Engineering University of ManitobaWinnipegMBR3T 5V6Canada Manitoba HVDC Research Center 211 Commerce DriveWinnipegMBR3P 1A3Canada IEEE

Power converters and their interfacing networks are often treated as modular state-space blocks for small-signal stability studies in microgrids;they are interconnected by matching the input and output states of the network and converters.Virtual resistors have been widely used in existing models to generate a voltage for state-space models of the network that require voltage inputs.This paper accurately quantifies the adverse impacts of adding the virtual resistance and proposes an alternative method for network modelling that eliminates the requirement of the virtual resistor when interfacing converters with microgrids.The proposed nonlinear method allows initialization,time-domain simulations of the nonlinear model,and linearization and eigenvalue generation.A numerically linearized small-signal model is used to generate eigenvalues and is compared with the eigenvalues generated using the existing modelling method with virtual resistances.Deficiencies of the existing method and improvements offered by the proposed modelling method are clearly quantified.Electromagnetic transient(EMT)simulations using detailed switching models are used for validation of the proposed modelling method.

关键词： Low-voltage converter state-space modelling dynamic phasor time-domain simulation eigenvalue analysis

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Seamless morphing trailing edge flaps for UAS-S45 using high-fidelity aerodynamic optimization

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Chinese Journal of Aeronautics 2024年第2期37卷 12-29页

作者： Mir Hossein NEGAHBAN Musavir BASHIR Victor TRAISNEL Ruxandra Mihaela BOTEZ LARCASE Laboratory of Applied Research in Active Controls Avionics and AeroservoelasticityEcole de Technologie SuperieureUniversite du QuebecMontreal H3C1K3Canada

The seamless trailing edge morphing flap is investigated using a high-fidelity steady-state aerodynamic shape optimization to determine its optimum configuration for different flight conditions,including climb,cruise,and gliding descent.A comparative study is also conducted between a wing equipped with morphing flap and a wing with conventional hinged flap.The optimization is performed by specifying a certain objective function and the flight performance goal for each flight condition.Increasing the climb rate,extending the flight range and endurance in cruise,and decreasing the descend rate,are the flight performance goals covered in this study.Various optimum configurations were found for the morphing wing by determining the optimum morphing flap deflection for each flight condition,based on its objective function,each of which performed better than that of the baseline wing.It was shown that by using optimum configuration for the morphing wing in climb condition,the required power could be reduced by up to 3.8%and climb rate increases by 6.13%.The comparative study also revealed that the morphing wing enhances aerodynamic efficiency by up to 17.8%and extends the laminar flow.Finally,the optimum configuration for the gliding descent brought about a 43%reduction in the descent rate.

关键词： Seamless morphing trailing edge flap Aerodynamic optimization Gradient-based optimiza-tion Climb flight condition Gliding descent Flight range Endurance

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A taxonomy of built asset information coupling

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Frontiers of Engineering Management 2024年第2期11卷 247-268页

作者： Saman DAVARI Erik POIRIER Department of Construction Engineering Ecole de technologie superieureMontreal H3C 1K3Canada

The digital transformation of the built asset industry is moving toward closer integration of physical and digital assets and resources.Within the framework of Cyber-Physical Systems(CPSs)and Digital Twins(DTs),an increasing number of studies focus on the technical aspects of CPS and DT.However,a unified framework describing the dimensions and characteristics essential for integrating lifecycle information remains elusive.To leverage these concepts effectively,it is necessary to develop new frameworks to classify and put into relationship various components that comprise the lifecycle information integration of physical and digital assets and resources.This paper addresses these gaps by proposing a taxonomy of Built Asset Lifecycle Information Couples,which outlines the dimensions and characteristics crucial for the lifecycle information integration of built assets and resources.The proposed taxonomy contributes to the efforts aimed at organizing the knowledge domain of lifecycle information management in the built environment.

关键词： asset coupling taxonomy digitalization lifecycle information management built environment

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Ensuring Secure Platooning of Constrained Intelligent and Connected Vehicles Against Byzantine Attacks:A Distributed MPC Framework

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Engineering 2024年第2期33卷 35-46页

作者： Henglai Wei Hui Zhang Kamal AI-Haddad Yang Shi Department of Mechanical Engineering University of VictoriaVictoriaBC V8W 3P6Canada School of Transportation Science and Engineering Beihang UniversityBeijing 100191China École de Technologie Supérieure University of QuebecMontrealQC H3C 1K3Canada

This study investigates resilient platoon control for constrained intelligent and connected vehicles(ICVs)against F-local Byzantine attacks.We introduce a resilient distributed model-predictive platooning control framework for such ICVs.This framework seamlessly integrates the predesigned optimal control with distributed model predictive control(DMPC)optimization and introduces a unique distributed attack detector to ensure the reliability of the transmitted information among vehicles.Notably,our strategy uses previously broadcasted information and a specialized convex set,termed the“resilience set”,to identify unreliable data.This approach significantly eases graph robustness prerequisites,requiring only an(F+1)-robust graph,in contrast to the established mean sequence reduced algorithms,which require a minimum(2F+1)-robust graph.Additionally,we introduce a verification algorithm to restore trust in vehicles under minor attacks,further reducing communication network robustness.Our analysis demonstrates the recursive feasibility of the DMPC optimization.Furthermore,the proposed method achieves exceptional control performance by minimizing the discrepancies between the DMPC control inputs and predesigned platoon control inputs,while ensuring constraint compliance and cybersecurity.Simulation results verify the effectiveness of our theoretical findings.

关键词： Model predictive control Resilient control Platoon control Intelligent and connected vehicle Byzantine attacks

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Laser-assisted direct roller imprinting of large-area microstructured optical surfaces

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Microsystems & Nanoengineering 2024年第1期10卷 257-266页

作者： Keisuke Nagato Ken Takahashi Yuki Yajima Masayuki Nakao Department of Mechanical Engineering Graduate School of EngineeringThe University of Tokyo7-3-1 HongoBunkyo-kuTokyo 113-8656Japan

In this study,a high-throughput fabrication method called laser-assisted direct roller imprinting(LADRI)was developed to lower the cost of nanoimprinting large-area polymer films and to address problems associated with nanoimprinting,namely,microstructural damage and precision in flatness of entire film.With LADRI,the laser directly heats the microstructured surface of the roller mold,which heats and melts the surface of a polymethyl methacrylate(PMMA)film to replicate the microstructures on the mold rapidly.In this study,the effects of laser power density,scanning speed,size of the microstructures,and contact pressure on the replication speed were investigated experimentally.The replication speed increased as the power and scanning speed increased.However,because the film required heating until it filled the entire depth of the microstructure,an appropriate replication speed was necessary.This result was supported by simulation of the temperature distribution inside the mold and the PMMA using transient heat conduction analyses.To demonstrate the applications of LADRI,two different optical surfaces were replicated:an antireflection(AR)structure with conical structures sized several hundred nanometers and a lightextraction structure with a microlens array(MLA)comprising 10μm lenses,for display and illumination,respectively.The replication degree of the MLA was governed by the contact pressure.Polymer flow simulation indicated that the heat conduction and flow speeds of the melted PMMA surface were comparable within several tens of micrometers.In addition,the reflectivity of the AR structure decreased from 4 to 0.5%,and the light intensity of the light-extraction structure increased by a factor of 1.47.

关键词： microstructure roller conduction

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Assessing efficacy of standard impregnation techniques on die-cast aluminum alloys using X-ray micro-CT

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China Foundry 2024年第3期21卷 276-286页

作者： Ajith Bandara Koichi Kan Katanaga Yusuke Natsuto Soga Akifumi Koike Toru Aoki Hamamatsu TSC Chuo Hatsumei Institute322 lida-choMinami-kuHamamatsu435-0028Japan Graduate School of Medical Photonics ShizuokaUniversityJohoku 3-5-1HamamatsuShizuoka432-8561Japan ANSeeN Inc Johoku 3-5-1HamamatsuShizuoka432-8561Japan Research Institute of Electronics ShizuokaUniversityJohoku 3-5-1HamamatsuShizuoka432-8561Japan

Utilizing lightweight Al alloys in various industrial applications requires achieving precise pressure tightness and leak requirements.Vacuum pressure impregnation(VPI)with thermosetting polymers is commonly used to address leakage defects in die-cast Al alloys.In this study,the efficacy of the VPI technique in sealing alloy parts was investigated using a combination of nondestructive micro X-ray computed tomography(micro XCT)and a standard leak test.The results demonstrate that the commonly used water leak test is insufficient for determining the sealing performance.Instead,micro XCT shows distinct advantages by enabling more comprehensive analysis.It reveals the presence of a low atomic number impregnates sealant within casting defects,which has low grey contrast and allows for visualizing primary leakage paths in 3D.The effective atomic number of impregnated resin is 6.75 and that of Al alloy is 13.69 by dual-energy X-ray CT.This research findings will contribute to enhancing the standard VPI process parameters and the properties of impregnating sealants to improve quality assurance for impregnation in industrial metals.

关键词： nondestructive testing Al alloy die-casting vacuum pressure impregnation micro X-ray computed tomography duel-energy X-ray CT

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Digital Social Connectedness as a Lifeline for Older People: Use and Non-use of VinclesBCN During the Pandemic

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International Journal of Disaster Risk Science 2024年第2期15卷 251-264页

作者： Israel Rodríguez-Giralt Daniel López-Gómez Roser Beneito-Montagut CareNet IN3 Universitat Oberta de Catalunya School of Social Sciences Cardiff University

This article presents the results of a study that evaluated VinclesBCN during COVID-19. This digital-based public social service aims to prevent loneliness and isolation in +65-year-old adults living in Barcelona. Through service user(N = 12) and professional(N = 6) interviews and a questionnaire with service users(N = 255), we demonstrate the pivotal role of digital connectedness in transforming VinclesBCN into a lifeline during the pandemic. The analysis revealed the importance of sociability, social support, and, especially, entertainment in coping with pandemic fatigue and facilitating social connectivity and support among users. Users engaged in activities such as sharing images, songs, memes, and daily greetings to provide proximity, sociability, and care among users, whether they belonged to preexisting groups or were newly introduced to the platform. It also facilitated the identification of individuals who needed companionship, comfort, or more specialized support. The findings emphasize the significance of entertainment as a resilience-building strategy during times of uncertainty. Despite the positive impact, not all users equally used the platform. Non-use was strongly associated with being a woman, having a low educational level, having preexisting social relationships, less time of enrolment in the platform, as well as a high perception of loneliness, poor self-reported health, and low mood. The article underscores the need for further research into older adults' digital engagement during crises, its role in building resilience, and advocating for inclusive digital interventions that take into account diverse older adults' needs and experiences in crisis contexts.

关键词： Barcelona COVID-19 pandemic Digital social connectedness Entertainment Older adult resilience Public digital service

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Previously undiagnosed Morgagni hernia with bowel perforation detected during repeat screening colonoscopy: A case report

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World Journal of Clinical Cases 2024年第14期12卷 2389-2395页

作者： Said Al Alawi Alan N Barkun Sara Najmeh Division of Gastroenterology McGill UniversityMontrealQC H4A 3J1Canada Division of Thoracic surgery McGill UniversityMontrealQC H4A 3J1Canada

BACKGROUND Morgagni hernia(MH)is a form of congenital diaphragmatic hernia(CDH)characterized by an incomplete formation of diaphragm,resulting in the protru-sion of abdominal organs into the thoracic cavity.The estimated incidence of CDH is between 1 in 2000 and 1 in 5000 live births,although the true incidence is unknown.MH typically presents in childhood and can be diagnosed either pre-natally or postnatally.However,it can also be asymptomatic and carry the risk of developing into a life-threatening condition in adulthood.CASE SUMMARY A 76-year-old female with no history of prior abdominal surgeries presented for an elective colonoscopy for polyp surveillance.During the procedure,when approaching the hepatic flexure,the scope could not be advanced further despite multiple attempts.The patient experienced mild abdominal discomfort,leading to the abortion of the procedure.While in the recovery area,she developed increa-sing abdominal pains and hypotension.Urgent abdominal imaging revealed her-niation of the proximal transverse colon through a MH into the chest with evi-dence of perforation.The patient underwent laparoscopic urgent colonic resection and primary hernia repair and was discharged uneventfully 2 d later.CONCLUSION A MH is a rare condition in adults that can present as a life-threatening compli-cation of colonoscopy,even in patients with a history of uneventful colonoscopies.This case highlights the importance of considering congenital and internal hernias when faced with sudden and unexplained difficulties during colonoscopy.If there is a suspicion of MH,the endoscopist should halt the procedure and immediately obtain abdominal imaging to confirm the diagnosis.

关键词： Bowel perforation Colonoscopy Adverse event Congenital diaphragmatic

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