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Guillen P.F.,National Autonomous University of Mexico | Vazquez R.,National Autonomous University of Mexico | Miranda L.F.,University of Vigo | Zavala S.,Technological Educational Institute of Mexico | And 4 more authors.
Monthly Notices of the Royal Astronomical Society | Year: 2013

We present narrow-band [O III]λ5007 and Hα images, as well as long-slit high-resolution echelle spectra of the planetary nebula NGC 6058. Our data reveal that NGC 6058 is a multipolar planetary nebula of ~45 arcsec in extent that is formed by four bipolar outflows oriented at different position angles. Assuming homologous expansion for all the structures, and a distance of 3.5 kpc, we obtain polar velocities of ~68 km s-1 for three of them. The estimated kinematical ages suggest that the three oldest outflows were ejected at intervals of ~1100 and ~400 yr, during which the ejection axis changed its orientation by ~60° and~40°, respectively. Although an inner ring-like structure is suggested by the direct images, the kinematics shows that no equatorial ring or toroid exists in the nebula. On the contrary, the long-slit spectra reveal that the ring-like structure corresponds to a fourth outflow that is oriented almost perpendicular to the other three. This fourth outflow is the youngest one and appears to be interacting with the other three, creating aprotruding zone that sweeps material in a region almost perpendicular to the major axes of the oldest outflows. This structure also presents two bright arcuate regions along the direction of the older outflows, and on opposite sides of the central star. From our model, we suggest thatNGC6058 could be at an intermediate evolutionary stage between starfish planetary nebulae and multipolar planetary nebula with apparent equatorial lobes. © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Source

Ramirez-Fernandez C.,Autonomous University of Baja California | Ramirez-Fernandez C.,Technological Educational Institute of Mexico | Garcia-Canseco E.,Autonomous University of Baja California | Moran A.L.,Autonomous University of Baja California | Gomez-Montalvo J.R.,Autonomous University of Yucatan
ACM International Conference Proceeding Series | Year: 2015

Today, the development of virtual reality (VR) applications for upper limb motor rehabilitation is still a dificult and time-consuming task. It requires developers to be skilled in motor rehabilitation, interaction devices, and stroke sur- vivor characteristics, among others, to be able to develop a virtual environment (VE). In the literature there are several recommendations to aid in the design of VEs. However, to integrate the recommendations it is necessary to understand key domain concepts in motor rehabilitation. In this paper, we introduce VEULMoR, an ontology-based approach for designing VEs for Upper Limb Motor Rehabilitation. This approach uses the domain expertise coded into the ontology to shorten and facilitate the design of a VE. The information contained in the ontology can be used to denote the design factors that integrate the VE. © 2015 ACM. Source

Hernandez D.E.,Research Center Cientifica Estudios Superiores Of Ensenada | Clemente E.,Research Center Cientifica Estudios Superiores Of Ensenada | Clemente E.,Technological Educational Institute of Mexico | Olague G.,Research Center Cientifica Estudios Superiores Of Ensenada | Briseno J.L.,Research Center Cientifica Estudios Superiores Of Ensenada
Journal of Computational Science | Year: 2015

In recent years computer vision systems have used the human visual system as inspiration for solving different tasks such as object detection and classification. Computational models as the artificial visual cortex (AVC) have shown promising results in solving such problems. Thus, this paper proposes a new methodology for creating an image descriptor vector for classification, and at the same time, finding the objects' location within the image. Also, this work implements the brain programming paradigm from a multi-objective perspective in order to improve the performance in the object classification task. This methodology is implemented for training the proposed model in order to classify the images from the GRAZ-01 and GRAZ-02 databases. The solutions found in this research match, and in some cases outperform, other techniques of the state-of-the-art for classifying the aforementioned databases. © 2015 Elsevier B.V. Source

Contreras M.E.,National Autonomous University of Mexico | Vazquez R.,National Autonomous University of Mexico | Miranda L.F.,Institute Astrofisica Of Andalucia | Miranda L.F.,University of Vigo | And 3 more authors.
Astronomical Journal | Year: 2010

We present an observational study of the planetary nebula (PN) NGC7354 consisting of narrowband Hα and [N II]λ6584 imaging as well as low- and high-dispersion long-slit spectroscopy, and VLA-D radio continuum. According to our imaging and spectroscopic data, NGC7354 has four main structures: a quite round outer shell and an elliptical inner shell, a collection of low-excitation bright knots roughly concentrated on the equatorial region of the nebula, and two asymmetrical jet-like features, not aligned either with the shells' axes, or with each other. We have obtained physical parameters like electron temperature and electron density as well as ionic and elemental abundances for these different structures. Electron temperature and electron density slightly vary throughout the nebula going from ≃11, 000 to ≃14, 000 K, and from ≃1000 to ≃ 3000 cm-3, respectively. The local extinction coefficient c Hβ shows an increasing gradient from south to north and a decreasing gradient from east to west consistent with the number of equatorial bright knots present in each direction. Abundance values show slight internal variations but most of them are within the estimated uncertainties. In general, abundance values are in good agreement with the ones expected for PNe. Radio continuum data are consistent with optically thin thermal emission. Mean physical parameters derived from the radio emission are electron density ne = 710 cm-3 and M(H II) = 0.22 M1. We have used the interactive three-dimensional modeling tool SHAPE to reproduce the observed morphokinematic structures in NGC7354 with different geometrical components. Our observations and model show evidence that the outer shell is moving faster (≃35 km s-1) than the inner one (≃ 30 km s-1). Our SHAPE model includes several small spheres placed on the outer shell wall to reproduce equatorial bright knots. Observed and modeled velocity for these spheres lies between the inner and outer shells velocity values. The two jet-like features were modeled as two thin cylinders moving at a radial velocity of ≃60kms-1. In general, our SHAPE model is in very good agreement with our imaging and spectroscopic observations. Finally, after modeling NGC7354 with SHAPE, we suggest a possible scenario for the formation of the nebula. © 2010 The American Astronomical Society. Source

Badilla G.L.,Mexicali Institute of Technology | GomeZ M.M.A.,Mexicali Institute of Technology | Samaniego E.R.,Technological Educational Institute of Mexico
Materials Performance | Year: 2015

The importance of boilers and related piping as a cost effective energy source that replaces the expensive electrical energy in the Mexicali region was studied. The evaluation consisted of two steps, analyzing the PPO in the interior side of the pipelines and proposing primary solutions to reduce corrosion, and suggesting secondary alternatives to avoid future corrosion. The evaluation was conducted over two years. Specimens of SS and CS, measuring 30 by 10 by 5 mm, matched the pipeline materials. Mass loss was monitored after 1, 3, 6, 12, and 24 months to track the development of corrosion products, and these data were correlated with the levels of RH and temperature during the corresponding seasons. After exposure of the metallic probes, a microanalysis with scanning electron microscopy (SEM) identified the composition of the corrosion products and the principal corroded metallic surfaces. The correlation analysis ranged from 20% RH and 20 °C to 75% RH and 40°C with good correlation to the CR. In these ranges, it was observed that the maximum and minimum levels showed good correlation between the three variables in the evaluation. These values included high temperatures that did not permit the accumulation of water on the metal surfaces, resulting in low time of wetness and minor localized pitting corrosion. Source

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