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Systematic exploration of signal-based indicators for failure diagnosis in the context of cyber-physical systems

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Frontiers of Information Technology & Electronic Engineering 2019年第2期20卷 152-175页

作者： Santiago RUIZ-ARENAS Zoltán RUSák Imre HORVáTH ricardo MEJí-GUTIERREZ Faculty of Industrial Design Engineering Delft University of Technology Grupo de Investigación en Ingeniería de Diseno Universidad EAFIT

Malfunction or breakdown of certain mission critical systems(MCSs) may cause losses of life, damage the environments, and/or lead to high costs. Therefore, recognition of emerging failures and preventive maintenance are essential for reliable operation of MCSs. There is a practical approach for identifying and forecasting failures based on the indicators obtained from real life processes. We aim to develop means for performing active failure diagnosis and forecasting based on monitoring statistical changes of generic signal features in the specific operation modes of the system. In this paper, we present a new approach for identifying emerging failures based on their manifestations in system signals. Our approach benefits from the dynamic management of the system operation modes and from simultaneous processing and characterization of multiple heterogeneous signal sources. It improves the reliability of failure diagnosis and forecasting by investigating system performance in various operation modes, includes reasoning about failures and forming of failures using a failure indicator matrix which is composed of statistical deviation of signal characteristics between normal and failed operations, and implements a failure indicator concept that can be used as a plug and play failure diagnosis and failure forecasting feature of cyber-physical systems. We demonstrate that our method can automate failure diagnosis in the MCSs and lend the MCSs to the development of decision support systems for preventive maintenance.

关键词： Failure indicators Failure classification Failure detection and diagnosis Complex systems

Engineering Geological Investigations for the Foundations of Large Structures-Examples of a Concrete Dam and a long Bridge in Portugal

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Journal of Mountain Science 2011年第2期8卷 296-306页

作者： ricardo OLIVEIRA COBA and New University of Lisbon Portugal

The safety of large structures requires adequate foundations, which implies a good knowledge of the geological and geotechnical conditions of the respective ground. In general, that is only possible through engineering geological studies which include proper site investigation techniques, adapted to the nature of the ground (rock mass or soil) and to the associated engineering problems. The paper illustrates the studies carried out for the design of the foundations of Ribeiradio 76 m high concrete gravity dam in a difficult rock mass and of Vasco da Gama Bridge, 13 km long, crossing the Tagus River in Lisbon, Portugal, through piles 75 m deep.

关键词： Geological investigation Foundations Concrete dam Bridge

Deduction and Validation of an Eulerian-Eulerian Model for Turbulent Dilute Two-Phase Flows by Means of the Phase Indicator Function-Disperse Elements Probability Density Function

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Chinese Journal of Chemical Engineering 2000年第3期8卷 189-202页

作者： Santiago Laín ricardo Aliod MVT-UST Fachbereich Ingenieurwissenschaften Martin-Luther-UniversitatHalle-WittenbergD-06099Halle(Saale)GermanyFluid Mechanica DepartmentE.U.Politecnica de Huesca.University of ZaragozaCarretera Zaragoza km.6722071 HuescaSpain

A statistical formalism overcoming some conceptual and practical difficulties arising in existing two-phase flow (2PHF) mathematical modelling has been applied to propose a model for dilute 2PHF turbulent Hows. Phase interaction terms with a clear physical meaning enter the equations and the formalism provides some guidelines for the avoidance of closure assumptions or the rational approximation of these terms. Continuous phase averaged continuity, momentum, turbulent kinetic energy and turbulence dissipation rate equations have been rigorously and systematically obtained in a single step. These equations display a structure similar to that for single-phase flows. It is also assumed that dispersed phase dynamics is well described by a probability density function (pdf) equation and Eulerian continuity, momentum and fluctuating kinetic energy equations for the dispersed phase are deduced. An extension of the standard k-e turbulence model for the continuous phase is used. A gradient transport model is adopted for the dispersed phase fluctuating fluxes of momentum and kinetic energy at the non-colliding, large inertia limit. This model is then used to predict the behaviour of three axisymmetric turbulent jets of air laden with solid particles varying in size and concentration. Qualitative and quantitative numerical predictions compare reasonably well with the three different sets of experimental results, studying the influence of particle size, loading ratio and flow confinement velocity.

关键词： two-phase flow turbulence phase indicator function pdf ensemble average jet

Synthesis identification analysis for closed loop system

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Journal of Systems Engineering and Electronics 2021年第4期32卷 939-946页

作者： WANG Jianhong ricardo A.Ramirez-Mendoza School of Electronic Engineering and Automation Jiangxi University of Science and TechnologyGanzhou 343100China School of Engineering and Sciences Tecnologico de MonterreyMonterrey 64849Mexico

The existing theories for closed loop identification with the linear feedback controller are very *** apply the existed theories directly in the control field,we propose a new idea about replacing the original unknown and nonlinear feedback controller with one approximated linear controller,while guaranteeing the equivalent property for the obtained closed loop *** on some statistical correlation functions,one condition is derived to show the equivalent property between the approximated linear controller and the original nonlinear *** detailed explicit form,corresponding to the approximated linear controller,is also ***,to give a complete analysis for closed loop identification,the cost function is rewritten as one extended expression,being convenient to *** spectral estimation is introduced to identify the unknown plant in the closed loop ***,the proposed theories are verified by one simulation example.

关键词： synthesis analysis closed loop system simplified function equivalent controller

Comprehensive Euler/Lagrange modelling including particle erosion for confined gas-solid flows

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Particuology 2024年第1期84卷 209-235页

作者： Guiherme A.Novelletto ricardo Martin Sommerfeld Multiphase Flow Systems Institute of Process EngineeringOtto-von-Guericke-University MagdeburgHoher Weg 7b06120Halle(Saale)Germany

The present research aims to assess the capability of a comprehensive Euler/Lagrange approach for predicting gas-solid flows and the associated solid particle *** open-source code OpenFOAM®4.1 was used to carry out the numerical simulations,where the standard Lagrangian libraries were substantially extended to account for all necessary *** are tracked considering both translational and rotational motion as well as all relevant forces,such as gravity/buoyancy,drag and transverse lift due to shear and particle *** tracking time step was dynamically adapted ac-cording to the locally relevant time scales,which drastically reduces computational *** approaches are adopted to model particle turbulent dispersion,particle collisions with rough walls and particle-particle *** solid particle erosion models,available in the literature,were considered to estimate pipe bend *** study cases are provided to validate the adopted nu-merical approach and erosion models *** first case intends to evaluate the ability of the extended CFD code to predict the behaviour of gas-solid flows in pneumatic conveying *** goal is achieved by comparing the numerical results with the experimental data obtained by Huber(1997)and Huber and Sommerfeld(1994,1998)in a pneumatic conveying ***,the importance of considering inter-particle collisions and surface roughness for predicting particle velocity,mass flux and mean diameter distributions in gas-solid flows is *** second and third case intend to evaluate the ability of the erosion models in estimating bend erosion in diluted gas-solid *** erosion data obtained experimentally by Mazumder et al.(2008)and Solnordal et al.(2015)in very dilut pneumatic conveying systems is used for validating the numerical results,neglecting now inter-particle collisions and two-way *** a comprehensive analysis of the different influential properti

关键词： Pneumatic conveying Pipe bend Numerical calculation(CFD) Euler/Lagrange approach Erosion models Wall roughness

A comprehensive review on biomarkers associated with painful temporomandibular disorders

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International Journal of Oral Science 2021年第3期13卷 230-242页

作者： Mayank Shrivastava ricardo Battaglino Liang Ye Department of Diagnostic and Biological Sciences School of DentistryUniversity of MinnesotaMinneapolisMNUSA Department of Rehabilitation Medicine Medical SchoolUniversity of MinnesotaMinneapolisMNUSA

Pain of the orofacial region is the primary complaint for which patients seek *** all the orofacial pain conditions,one condition that possess a significant global health problem is temporomandibular disorder(TMD).Patients with TMD typically frequently complaints of pain as a *** can occur due to complex interplay between peripheral and central sensitization,endogenous modulatory pathways,and cortical *** diagnosis of TMD pain a descriptive history,clinical assessment,and imaging is ***,due to the complex nature of pain an additional step is needed to render a definitive TMD *** this review we explicate the role of different biomarkers involved in painful *** painful TMD conditions,the role of biomarkers is still *** believe that the identification of biomarkers associated with painful TMD may stimulate researchers and clinician to understand the mechanism underlying the pathogenesis of TMD and help them in developing newer methods for the diagnosis and management of ***,to understand the potential relationship of biomarkers,and painful TMD we categorize the biomarkers as molecular biomarkers,neuroimaging biomarkers and sensory *** addition,we will briefly discuss pain genetics and the role of potential microRNA(miRNA)involved in TMD pain.

关键词： diagnosis endogenous facial

Improved inclination correction method applied to the guidance system of agricultural vehicles

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International Journal of Agricultural and Biological Engineering 2020年第6期13卷 183-194页

作者： ricardo Ospina Noboru Noguchi Research Faculty of Agriculture Hokkaido UniversitySapporo 060-8589 HokkaidoJapan

This research introduces a new inclination correction method with increased accuracy applied to the guidance system of an agricultural *** method considers the geometry of a robot tractor and uses an Inertial Measurement Unit(IMU)to correct the lateral error of the RTk-GPS antenna measurements raised by the tractor's inclinations.A parameters optimization experiment and an automatic guidance experiment under real working conditions were used to compare the accuracy of a traditional correction method with the new correction method,by calculating the RMSE of the lateral error and the error reduction *** additional tuned correction method was found by using a simple analytical method to find the optimal variables that reduced the lateral error to a *** results indicate that the new correction method and the tuned correction method display a significant error reduction percentage compared to the traditional correction *** methods could correct the GPS lateral error caused by the roll inclinations in *** resulting lateral deviation caused by the tractor's inclinations could be reduced up to 23%for typical travelling speeds.

关键词： inclination correction method guidance system agricultural vehicles robot tractor IMU RTk-GPS precision farming

Macrophages and the maintenance of homeostasis

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Cellular & Molecular Immunology 2021年第3期18卷 579-587页

作者： David M.Mosser kajal Hamidzadeh ricardo Goncalves The Department of Cell Biology and Molecular Genetics The University of MarylandCollege ParkMD 20742USA The Department of General Pathology Federal University of Minas GeraisBelo HorizonteMGBrazil

There have been many chapters written about macrophage *** chapters generally focus on the role of macrophages in orchestrating immune responses by highlighting the T-cell-derived cytokines that shape these polarizing *** bias toward immunity is understandable,given the importance of macrophages to host ***,macrophages are ubiquitous and are involved in many different cellular processes,and describing them as immune cells is undoubtedly an *** disregards their important roles in development,tissue remodeling,wound healing,angiogenesis,and metabolism,to name just a few *** this chapter,we propose that macrophages function as transducers in the *** to Wikipedia,WA transducer is a device that converts energy from one form to another.^The word transducer is a term used to describe both the"sensor,which can interpret a wide range of energy forms,and the"actuator,which can switch voltages or currents to affect the *** are able to sense a seemingly endless variety of inputs from their environment and transduce these inputs into a variety of different response ***,rather than functioning as immune cells,they should be considered more broadly as cellular transducers that interpret microenvironmental changes and actuate vital tissue *** this chapter,we will describe some of the sensory stimuli that macrophages perceive and the responses they make to these stimuli to achieve their prime directive,which is the maintenance of homeostasis.

关键词： Macrophages polarization cytokines development inflammation

Nonlinear direct data-driven control for UAV formation flight system

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Journal of Systems Engineering and Electronics 2023年第6期34卷 1409-1418页

作者： WANG Jianhong ricardo A.RAMIREZ-MENDOZA XU Yang School of Engineering and Sciences Tecnologico de MonterreyMonterrey 64849Mexico School of Civil Aviation Northwestern Polytechnical UniversityXi’an 710072China

This paper proposes the nonlinear direct data-driven control from theoretical analysis and practical engineering,i.e.,unmanned aerial vehicle(UAV)formation flight ***,from the theoretical point of view,consider one nonlinear closedloop system with a nonlinear plant and nonlinear feed-forward controller *** avoid the complex identification process for that nonlinear plant,a nonlinear direct data-driven control strategy is proposed to design that nonlinear feed-forward controller only through the input-output measured data sequence directly,whose detailed explicit forms are model inverse method and approximated analysis ***,from the practical point of view,after reviewing the UAV formation flight system,nonlinear direct data-driven control is applied in designing the formation controller,so that the followers can track the leader’s desired trajectory during one small time instant only through solving one data fitting *** most natural phenomena have nonlinear properties,the direct method must be the better *** system identification and control algorithms are required to be proposed for those nonlinear systems,and the direct nonlinear controller design is the purpose of this paper.

关键词： nonlinear system nonlinear direct data-driven control model inverse control unmanned aerial vehicle(UAV)formation flight.