Agent-Based Approach to Distributed Ensemble Learning of Fuzzy ARTMAP Classifiers

Cervantes, L.,Lee, J.-s.,Lee, J. SPRINGER-VERLAG 2007 ICHIT 2012 Vol.4496 No.-

Synthesis of branched geminal zwitterionic liquids as wettability modifiers in enhanced oil recovery processes

J.F. Ramı´rez-Pe´ rez,R. Herna´ndez-Altamirano,J.M. Martı´nez-Magada´n,R. Cartas-Rosado,E. Soto-Castruita,R. Cisneros-Devora,L.A. Alca´ zar-Vara,R. Oviedo-Roa,V.Y. Mena-Cervantes,L.S. Zamudio-Rivera 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.45 No.-

A new class of branched geminal zwitterionic liquids (BGZLs) betaine base with a long alkyl chains witheither 8 (BGZL-ZW8) or 12 (BGZL-ZW12) carbons was synthesized and characterized by nuclearmagnetic resonance (NMR) and Fourier transform infrared (FTIR) spectroscopic techniques. The BGZLsmolecules presents functionality as viscosity reducer and wettability modifier with application inenhanced oil recovery (EOR) processes with good oil recovery factors (ORF). The above is demonstratedby performing spontaneous imbibition tests on embedded limestone cores with light and heavy crudeoils in Amott cells at high temperature (90 8C) and different concentrations of BGZLs in presence ofconnate water with high salinity and hardness (36,275 ppm as NaCl and 6700 ppm hardness as CaCO3). The rheological behavior of BGZLs was also determined as viscosity reducers in heavy crude oil atconcentrations of 2000, 1000 and 500 ppm at temperatures of 25 and 40 8C, in the range of 36.11% to25 8C and 43.31% to 40 8C. To explain the mechanism through BGZLs act as viscosity reducers, werealized theoretical studies using the density functional theory (DFT), also as wettability modifierstaking BGZL-ZW8 and BGZL-ZW12 behavior, observed in the experimental part. The interaction energiesshow that BGZLs can disaggregate asphaltene (Asph) dimmer (Asph:Asph) by the formation ofsupramolecular sandwich complex (Asph:BGZL:Asph) among BGZLs and Asph:Asph, modifying theproperties of crude oil such as viscosity, is possible to support the fact of the BGZLs can desorbs Asphmolecules of the rock surface, modifying the calcite surface (Cs) wettability of oil-wet to water-wet. Theresults of this research show that it is feasible the use of zwitterionic liquids as viscosity and wettabilitymodifier in EOR process.

Agent-Based Intelligent Decision Support for the Home Healthcare Environment

Cervantes, L.,Lee, Y.-S.,Yang, H.,Ko, S.-h.,Lee, J. SPRINGER-VERLAG 2007 ICHIT 2012 Vol.4413 No.-

Performance of carbon fiber added to anodes of conductive cement-graphite pastes used in electrochemical chloride extraction in concretes

M. J. Pellegrini-Cervantes,C. P. Barrios-Durstewitz,R. E. Nú,ñ,ez-Jaquez,F. J. Baldenebro-Lopez,R. Corral-Higuera,S. P. Arredondo-Rea,M. Rodriguez-Rodriguez,O. Llanes-Cardenas,R. Beltran-Chaco 한국탄소학회 2018 Carbon Letters Vol.26 No.-

Pollution of chloride ion-reinforced concrete can trigger active corrosion processes that reduce the useful life of structures. Multifunctional materials used as a counter-electrode by electrochemical techniques have been used to rehabilitate contaminated concrete. Cement-based pastes added to carbonaceous material, fibers or dust, have been used as an anode in the non-destructive Electrochemical Chloride Extraction (ECE) technique. We studied the performance of the addition of Carbon Fiber (CF) in a cement-graphite powder base paste used as an anode in ECE of concretes contaminated with chlorides from the preparation of the mixture. The experimental parameters were: 2.3% of free chlorides, 21 days of ECE application, a Carbon Fiber Volume Fraction (CFVF) of 0.1, 0.3, 0.6, 0.9%, a lithium borate alkaline electrolyte, a current density of 4.0 A / m2 and a cement/graphite ratio of 1.0 for the paste. The efficiency of the ECE in the traditional technique using metal mesh as an anode was 77.6% and for CFVF of 0.9% it was 90.4%, with a tendency to increase to higher percentages of the CFVF in the conductive cement-graphite paste, keeping the pH stable and achieving a homogeneous ECE in the mass of the concrete contaminated with chlorides.

Spectroscopic needs for imaging dark energy experiments

Newman, J.A.,Abate, A.,Abdalla, F.B.,Allam, S.,Allen, S.W.,Ansari, R.,Bailey, S.,Barkhouse, W.A.,Beers, T.C.,Blanton, M.R.,Brodwin, M.,Brownstein, J.R.,Brunner, R.J.,Carrasco Kind, M.,Cervantes-Cota, North-Holland 2015 Astroparticle physics Vol.63 No.-

Ongoing and near-future imaging-based dark energy experiments are critically dependent upon photometric redshifts (a.k.a. photo-z's): i.e., estimates of the redshifts of objects based only on flux information obtained through broad filters. Higher-quality, lower-scatter photo-z's will result in smaller random errors on cosmological parameters; while systematic errors in photometric redshift estimates, if not constrained, may dominate all other uncertainties from these experiments. The desired optimization and calibration is dependent upon spectroscopic measurements for secure redshift information; this is the key application of galaxy spectroscopy for imaging-based dark energy experiments. Hence, to achieve their full potential, imaging-based experiments will require large sets of objects with spectroscopically-determined redshifts, for two purposes:*Training: Objects with known redshift are needed to map out the relationship between object color and z (or, equivalently, to determine empirically-calibrated templates describing the rest-frame spectra of the full range of galaxies, which may be used to predict the color-z relation). The ultimate goal of training is to minimize each moment of the distribution of differences between photometric redshift estimates and the true redshifts of objects, making the relationship between them as tight as possible. The larger and more complete our ''training set'' of spectroscopic redshifts is, the smaller the RMS photo-z errors should be, increasing the constraining power of imaging experiments. Requirements: Spectroscopic redshift measurements for ~30,000 objects over >~15 widely-separated regions, each at least ~20arcmin in diameter, and reaching the faintest objects used in a given experiment, will likely be necessary if photometric redshifts are to be trained and calibrated with conventional techniques. Larger, more complete samples (i.e., with longer exposure times) can improve photo-z algorithms and reduce scatter further, enhancing the science return from planned experiments greatly (increasing the Dark Energy Task Force figure of merit by up to ~50%). Options: This spectroscopy will most efficiently be done by covering as much of the optical and near-infrared spectrum as possible at modestly high spectral resolution (λ/Δλ>~3000), while maximizing the telescope collecting area, field of view on the sky, and multiplexing of simultaneous spectra. The most efficient instrument for this would likely be either the proposed GMACS/MANIFEST spectrograph for the Giant Magellan Telescope or the OPTIMOS spectrograph for the European Extremely Large Telescope, depending on actual properties when built. The PFS spectrograph at Subaru would be next best and available considerably earlier, c. 2018; the proposed ngCFHT and SSST telescopes would have similar capabilities but start later. Other key options, in order of increasing total time required, are the WFOS spectrograph at TMT, MOONS at the VLT, and DESI at the Mayall 4m telescope (or the similar 4MOST and WEAVE projects); of these, only DESI, MOONS, and PFS are expected to be available before 2020. Table 2-3 of this white paper summarizes the observation time required at each facility for strawman training samples. To attain secure redshift measurements for a high fraction of targeted objects and cover the full redshift span of future experiments, additional near-infrared spectroscopy will also be required; this is best done from space, particularly with WFIRST-2.4 and JWST. Calibration: The first several moments of redshift distributions (the mean, RMS redshift dispersion, etc.), must be known to high accuracy for cosmological constraints not to be systematics-dominated (equivalently, the moments of the distribution of differences between photometric and true redshifts could be determined instead). The ultimate goal of calibration is to characterize these moments for every subsample used in analyses - i.e., to minimi

Flight Control Design using Incremental Nonlinear Dynamic Inversion with Fixed-lag Smoothing Estimation

Ludeña Cervantes Tito J.,최성환,김병수 한국항공우주학회 2020 International Journal of Aeronautical and Space Sc Vol.21 No.4

In this study, a flight control design strategy based on incremental nonlinear dynamic inversion (INDI) and smoothing algorithm is presented. The INDI is an enhanced version of the nonlinear dynamic inversion technique with a better robust performance. It reduces the aircraft model dependence via the feedback information of the state derivative, that is, angular acceleration for the aircraft attitude motion (or angular velocity related to the wind axis parameters). However, the state derivatives cannot always be obtained by direct measurement, thus they need to be estimated on-line. Moreover, taking into account that INDI requires one-step delay of state derivative and the fact that the inertial measurement unit (IMU) operates faster than the flight control computer (FCC), there will be additional information that can be used to improve the estimation. Therefore, a fixed-lag smoothing algorithm based on a discrete Kalman filter is proposed for angular velocity and angular acceleration estimation. The smoother utilizes the state variable from the sensor measurement and thus dealing with noise and delay.

A novel approach for the rigid body guidance synthesis of planar RRPR linkages

Selma J. Rodríguez-González,Henry A. Suárez-Velásquez,J. Jesús Cervantes-Sánchez,José M. Rico-Martínez 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.2

This paper demonstrates that the maximum number of poses that can be exactly reached by a planar RRPR linkage is four, while the design for five poses requires the relaxation of displacement constraints at one prescribed pose. To this end, a novel and explicit condition for the synthesis of RP dyads with five prescribed poses is correspondingly introduced. It leads to a new and efficient approach to synthesize planar RRPR linkages, which is equipped with a branching identification procedure. Two successful case studies are provided to validate the applicability of the proposed synthesis approach.

Characteristics of Synchronous and Asynchronous modes of fluctuations in Francis turbine draft tube during load variation

Goyal, Rahul,Cervantes, Michel J.,Gandhi, Bhupendra K. Korean Society for Fluid machinery 2017 International journal of fluid machinery and syste Vol.10 No.2

Francis turbines are often operated over a wide load range due to high flexibility in electricity demand and penetration of other renewable energies. This has raised significant concerns about the existing designing criteria. Hydraulic turbines are not designed to withstand large dynamic pressure loadings on the stationary and rotating parts during such conditions. Previous investigations on transient operating conditions of turbine were mainly focused on the pressure fluctuations due to the rotor-stator interaction. This study characterizes the synchronous and asynchronous pressure and velocity fluctuations due to rotor-stator interaction and rotating vortex rope during load variation, i.e. best efficiency point to part load and vice versa. The measurements were performed on the Francis-99 test case. The repeatability of the measurements was estimated by providing similar movement to guide vanes twenty times for both load rejection and load acceptance operations. Synchronized two dimensional particle image velocimetry and pressure measurements were performed to investigate the dominant frequencies of fluctuations, vortex rope formation, and modes (rotating and plunging) of the rotating vortex rope. The time of appearance and disappearance of rotating and plunging modes of vortex rope was investigated simultaneously in the pressure and velocity data. The asynchronous mode was observed to dominate over the synchronous mode in both velocity and pressure measurements.

Numerical Calculation of the Heat Transfer Coefficient in a Turbulent Particle Pipe Flow

R. Avila,J. Cervantes 대한기계학회 1993 International Symposium on Transport Phenomena in Vol.2 No.1

Characteristics of Synchronous and Asynchronous modes of fluctuations in Francis turbine draft tube during load variation

Rahul Goyal,Michel J. Cervantes,Bhupendra K. Gandhi 한국유체기계학회 2017 International journal of fluid machinery and syste Vol.10 No.2

Francis turbines are often operated over a wide load range due to high flexibility in electricity demand and penetration of other renewable energies. This has raised significant concerns about the existing designing criteria. Hydraulic turbines are not designed to withstand large dynamic pressure loadings on the stationary and rotating parts during such conditions. Previous investigations on transient operating conditions of turbine were mainly focused on the pressure fluctuations due to the rotor-stator interaction. This study characterizes the synchronous and asynchronous pressure and velocity fluctuations due to rotor-stator interaction and rotating vortex rope during load variation, i.e. best efficiency point to part load and vice versa. The measurements were performed on the Francis-99 test case. The repeatability of the measurements was estimated by providing similar movement to guide vanes twenty times for both load rejection and load acceptance operations. Synchronized two dimensional particle image velocimetry and pressure measurements were performed to investigate the dominant frequencies of fluctuations, vortex rope formation, and modes (rotating and plunging) of the rotating vortex rope. The time of appearance and disappearance of rotating and plunging modes of vortex rope was investigated simultaneously in the pressure and velocity data. The asynchronous mode was observed to dominate over the synchronous mode in both velocity and pressure measurements.