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Model-based f.amework f.r multi-axial real-time hybrid simulation testing

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Earthquake Engineering and Engineering Vibration 2017年第4期16卷 671-691页

作者： Gaston A.f.rmandois Billie f.Spencer,jr. Department of.Civil and Environmental Engineering University of Illinois at Urbana-ChampaignUrbanaIL 61801USA

Real-time hybrid simulation is an ef.icient and cost-ef.ective dynamic testing technique f.r perf.rmance evaluation of.structural systems subjected to earthquake loading with rate-dependent behavior. A loading assembly with multiple actuators is required to impose realistic boundary conditions on physical specimens. However, such a testing system is expected to exhibit signif.cant dynamic coupling of.the actuators and suf.er f.om time lags that are associated with the dynamics of.the servo-hydraulic system, as well as control-structure interaction （CSI）. One approach to reducing experimental errors considers a multi-input, multi-output （MIMO） controller design, yielding accurate ref.rence tracking and noise rejection. In this paper, a f.amework f.r multi-axial real-time hybrid simulation （maRTHS） testing is presented. The methodology employs a real-time f.edback-f.edf.rward controller f.r multiple actuators commanded in Cartesian coordinates. Kinematic transf.rmations between actuator space and Cartesian space are derived f.r all six-degrees-of. f.eedom of.the moving platf.rm. Then, a f.equency domain identif.cation technique is used to develop an accurate MIMO transf.r f.nction of.the system. f.rther, a Cartesian-domain model-based f.edf.rward-f.edback controller is implemented f.r time lag compensation and to increase the robustness of.the ref.rence tracking f.r given model uncertainty. The f.amework is implemented using the 1/5th-scale Load and Boundary Condition Box （LBCB） located at the University of.Illinois at Urbana- Champaign. To demonstrate the ef.icacy of.the proposed methodology, a single-story f.ame subjected to earthquake loading is tested. One of.the columns in the f.aane is represented physically in the laboratory as a cantilevered steel column. f.r real- time execution, the numerical substructure, kinematic transf.rmations, and controllers are implemented on a digital signal processor. Results show excellent perf.rmance of.the maRTHS f.amework when

关键词： real-time hybrid simulation multiple actuators dynamic coupling kinematic transf.rmations model-basedcompensation

TopSTO:a 115-line code f.r topology optimization of.structures under stationary stochastic dynamic loading

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Earthquake Engineering and Engineering Vibration 2023年第4期22卷 1081-1100页

作者： Sebastian Pozo f.rnando Gomez Thomas Golecki Juan Carrion Billie f.Spencer jr. Civil and Environmental Engineering University of Illinois at Urbana-ChampaignUrbana 61801ILUSA College of.Science and Engineering Universidad San Francisco de QuitoDiego de Robles y Vía InteroceanicaQuitoEcuador Skidmore Owings&MerrillLLPChicago 60604ILUSA Department of.Civil Engineering University of CuencaCuencaEcuador

The use of.topology optimization in structural design under dynamic excitation is becoming more prevalent in the *** many such applications utilize f.equency or time domain f.rmulations,relatively f.w consider stochastic dynamic *** paper presents an ef.icient and compact code called TopSTO f.r structural topology optimization considering stationary stochastic dynamic loading using a method derived f.om random vibration *** theory,described in conjunction with the implementation in the provided code,is illustrated f.r a seismically excited *** work demonstrates the ef.iciency of.the approach in terms of.both the computational resources and minimal amount of.code *** code is intended to serve as a baseline f.r understanding the theory and implementation of.this topology optimization approach and as a f.undation f.r additional applications and developments.

关键词： topology optimization stochastic dynamics matlab python

SnRK1a1, a new player in the sucrose-Opaque2 network during endosperm f.lling

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Molecular Plant 2024年第8期17卷 1172-1174页

作者： Kelly Mayrink Balmant Marcio f.R.Resende jr. Horticultural Sciences Department University of FloridaGainesvilleFLUSA

Maize(Zea mays)endosperm is an important f.od source f.r humans and *** addition,it is considered an excellent model f.r research on seed development because of.its relatively large size f.r both embryo and endosperm compared to those of.other crop species,such as rice(Oryza sativa)and wheat(Triticum aestivum).Af.er double f.rtilization,early maize endosperm development includes three stages:(i)a multinucleate coenocyte stage;(i)a cellularization stage,in which the cellular endosperm is f.rmed;and(ii)a stage of.dif.erentiation into distinct *** early dif.erentiation,f.ur major cell types with specif.c f.nctions dif.erentiate within the endosperm:starchy endosperm,aleurone layer,basal endosperm transf.r layer(BETL),and embryo surrounding *** subaleurone,conducting zone,basal intermediate zone,and endosperm adjacent to scutellum arise in late dif.erentiation(Sabelli and Larkins 2009).Af.er the main cell types are established,maize endosperm undergoes intensive cell prolif.ration,which marks the transition to the endosperm-f.lling *** the endosperm-f.ling stage,the maternal sucrose products are transported to seeds through the BETL region,where they will act as the main carbon substrate f.r storage products such as starch and proteins(Chen et al.,2023).In f.ct,the endosperm of.maize seeds accounts f.r approximately 90%of.the total grain weight,serving as an important nutrient reservoir(f.int-Garcia et al.,2009).

关键词： endosperm reservoir f.int

A phased approach to enable hybrid simulation of.complex structures

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Earthquake Engineering and Engineering Vibration 2014年第S1期13卷 63-77页

作者： Billie f.Spencer jr. Chia-Ming Chang Thomas M.f.ankie Daniel A.Kuchma Pedro f.Silva Adel E.Abdelnaby Department of.Civil Engineering University of Illinois at Urbana-Champaign Nathan M.& Anne M.Newmark Endowed Chair Earthquake Engineering Research &Test Center Guangzhou University Associate Prof.ssor Wiss JanneyElstner AssociatesInc. Department of.Civil and Environmental Engineering University of Illinois at Urbana-Champaign Department of.Civil and Environmental Engineering George Washington University Department of.Civil Engineering University of Memphis Assistant Prof.ssor

Hybrid simulation has been shown to be a cost-ef.ective approach f.r assessing the seismic perf.rmance of.structures. In hybrid simulation,critical parts of.a structure are physically tested,while the remaining portions of.the system are concurrently simulated computationally,typically using a f.nite element model. This combination is realized through a numerical time-integration scheme,which allows f.r investigation of.f.ll system-level responses of.a structure in a cost-ef.ective manner. However,conducting hybrid simulation of.complex structures within large-scale testing f.cilities presents signif.cant challenges. f.r example,the chosen modeling scheme may create numerical inaccuracies or even result in unstable simulations; the displacement and f.rce capacity of.the experimental system can be exceeded; and a hybrid test may be terminated due to poor communication between modules(e.g.,loading controllers,data acquisition systems,simulation coordinator). These problems can cause the simulation to stop suddenly,and in some cases can even result in damage to the experimental specimens; the end result can be f.ilure of.the entire experiment. This study proposes a phased approach to hybrid simulation that can validate all of.the hybrid simulation components and ensure the integrity largescale hybrid simulation. In this approach,a series of.hybrid simulations employing numerical components and small-scale experimental components are examined to establish this preparedness f.r the large-scale experiment. This validation program is incorporated into an existing,mature hybrid simulation f.amework,which is currently utilized in the Multi-Axial f.ll-Scale Sub-Structuring Testing and Simulation(MUST-SIM) f.cility of.the George E. Brown Network f.r Earthquake Engineering Simulation(NEES) equipment site at the University of.Illinois at Urbana-Champaign. A hybrid simulation of.a f.ur-span curved bridge is presented as an example,in which three piers are experimentally controlle

关键词： hybrid simulation seismic perf.rmance evaluation phased approach curved bridge MUST-SIM f.cility

Advances in Computer Vision-Based Civil Inf.astructure Inspection and Monitoring

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Engineering 2019年第2期5卷 199-222页

作者： Billie f. Spencer jr. Vedhus Hoskere Yasutaka Narazaki Department of.Civil and Environmental Engineering University of Illinois at Urbana-Champaign Urbana IL 61801-2352 USA Department of.Computer Science University of Illinois at Urbana-Champaign Urbana IL 61801-2302 USA

Computer vision techniques, in conjunction with acquisition through remote cameras and unmanned aerial vehicles (UAVs), of.er promising non-contact solutions to civil inf.astructure condition assessment. The ultimate goal of.such a system is to automatically and robustly convert the image or video data into actionable inf.rmation. This paper provides an overview of.recent advances in computer vision techniques as they apply to the problem of.civil inf.astructure condition assessment. In particular, relevant research in the f.elds of.computer vision, machine learning, and structural engineering is presented. The work reviewed is classif.ed into two types: inspection applications and monitoring applications. The inspection applications reviewed include identif.ing context such as structural components, characterizing local and global visible damage, and detecting changes f.om a ref.rence image. The monitoring applications discussed include static measurement of.strain and displacement, as well as dynamic measurement of.displacement f.r modal analysis. Subsequently, some of.the key challenges that persist toward the goal of.automated vision-based civil inf.astructure and monitoring are presented. The paper concludes with ongoing work aimed at addressing some of.these stated challenges.

关键词： Structural inspection and monitoring Artif.cial intelligence Computer vision Machine learning Optical f.ow

Potential of.polyphenols in curbing quorum sensing and biof.lm f.rmation in Gramnegative pathogens

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Asian Pacif.c Journal of.Tropical Biomedicine 2021年第6期11卷 231-243页

作者： Arnica f.Lal Shaminder Singh f.ancisco C.f.anco,jr. Sonam Bhatia Department of.Pharmaceutical Science SHALOM Institute of Health and Allied SciencesSam Higginbottom University of AgricultureTechnology and SciencesNainiPrayagrajIndia Regional Centre f.r Biotechnology NCR Biotech Science Cluster3rd MilestoneFaridabad-Gurugram ExpresswayFaridabad-121001HaryanaIndia Chemistry Department De La Salle Univers2401 Taft Ave.Manila 0922Philippines

Polyphenols are the secondary metabolic products of.plants and are considered as active constituents to possess therapeutic *** date,a vast number of.scientif.c literature addressed the potential of.polyphenols as bio-ef.icient compounds owing to their structural *** to the presence of.several hydroxyl groups,they are metabolized quickly due to conjugation reaction and thus,readily produce toxic metabolites as a def.nse material against many pathogens,ref.ecting their saf.ty *** review f.cuses on the anti-quorum sensing and biof.lm inhibition activity of.polyphenols,which display their potential to treat bacterial inf.ctions by combating the virulence caused by pathogenic ***,f.r mitigating quorum sensing-controlled pathogenesis,the use of.polyphenol-based phytochemicals holds immense potential to cure *** application of.polyphenol as sensitizing agent/adjuvant therapeutics which act in synergism with antibiotics is highly remarkable.

关键词： Polyphenols Quorum sensing Biof.lm Recombinant polyphenolic compounds Sensitizers Antibiotic resistance

Photoluminescent Tb^(3+)-based metal-organic f.amework as a sensor f.r detection of.methanol in ethanol f.el

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Journal of.Rare Earths 2019年第3期37卷 225-231页

作者： Ramon R.f.f.nseca Raf.el D.L.Gaspar Ivo M.Raimundo jr. Priscilla P.Luz Department of.Chemistry Federal University of Espírito Santo Institute of.Chemistry University of Campinas

The sensing capability of.a Tb^(3+)-metal-organic f.amework, based on its photoluminescence, was used f.r detection of.methanol in ethanol f.el. It was synthesized using terbium and trimesic acid as a metal ion center and ligand, respectively. Powder X-ray dif.raction, inf.ared spectroscopy, thermogravimetric analysis and scanning electron microscopy were employed to characterize the synthesized MOf.76 structural f.atures. According to the results, MOf.76 was successf.lly obtained with minor synthetic modif.cation and its activated f.rm(named TbTMA) was tested as a sensor f.r methanol. Tb^(3+) luminescence intensity increases as the methanol concentration in ethanol f.el also increases and the water content does not af.ect this response. Our f.ndings indicate TbTMA as an appropriate sensor f.r evaluating ethanol f.el adulteration by methanol addition above the allowed limit.

关键词： Lanthanide Metal-organic f.ameworks Luminescence Ethanol f.el Sensor Adulteration

Localized-states quantum conf.nement induced by roughness in CdMnTe/CdTe heterostructures grown on Si(111) substrates

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Journal of.Semiconductors 2024年第9期45卷 28-35页

作者： Leonarde N.Rodrigues Wesley f.Inoch Marcos L.f.Gomes Odilon D.D.Couto jr. Bráulio S.Archanjo Sukarno O.f.rreira Physics Department Federal University of ViçosaViçosa36570-900Minas GeraisBrazil Instituto de f.sica Gleb Wataghin Universidade Estadual de CampinasCampinas13083-859São PauloBrazil National Institute of.Metrology Quality and Technology(Inmetro) Materials Metrology Division(DIMAT)Xerém2525-020Rio de JaneiroBrazil

This work shows that despite a lattice mismatch of.almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have dif.erent conf.nement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV)is associated to def.cts and bound exciton states, while the main emission at 1.61 eV has a weak 2D character and the higher energy one at 1.71 eV has a well-def.ned (zero-dimensional, 0D) 0D nature. Micro-photoluminescence measurements show the existence of.sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of.Mn in the heterostructure. This result opens the possibility of.producing photon sources with the typical spin control of.the diluted magnetic semiconductors using the low-cost silicon technology.

关键词： CdMnTe/CdTe/CdMnTe heterostructure CdTe/CdMnTe quantum emitters quantum dot-like emission silicon(111)substrate

Development of.a building inf.rmation model-guided post-earthquake building inspection f.amework using 3D synthetic environments

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Earthquake Engineering and Engineering Vibration 2023年第2期22卷 279-307页

作者： Nathaniel M.Levine Yasutaka Narazaki Billie f.Spencer Department of.Civil and Environmental Engineering University of Illinois at Urbana-ChampaignUrbanaIllinois 61801USA Zhejiang University-University of.Illinois at Urbana-Champaign Institute Zhejiang UniversityHaining 314400China

Computer vision-based inspection methods show promise f.r automating post-earthquake building *** methods survey a building with unmanned aerial vehicles and automatically detect damage in the collected ***,assessing the damage′s impact on structural saf.ty requires localizing damage to specif.c building components with known design and *** paper proposes a BIM-based automated inspection f.amework to provide context f.r visual surveys.A deep learning-based semantic segmentation algorithm is trained to automatically identif. damage in *** BIM automatically associates any identif.ed damage with specif.c building ***,components are classif.ed into damage states consistent with component f.agility models f.r integration with a structural *** demonstrate the f.amework,methods are developed to photorealistically simulate severe structural damage in a synthetic computer graphics environment.A graphics model of.a real building in Urbana,Illinois,is generated to test the f.amework;the model is integrated with a structural analysis to apply earthquake damage in a physically realistic manner.A simulated UAV survey is f.own of.the graphics model and the f.amework is *** method achieves high accuracy in assigning damage states to visible structural *** assignment enables integration with a perf.rmance-based earthquake assessment to classif. building saf.ty.

关键词： computer vision earthquake engineering building inf.rmation model physics-based graphics model synthetic environment