UNACAR

Campeche, Mexico
Campeche, Mexico
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Cerecedo-Nunez H.H.,University of Veracruz | Alvarado-Zacarias J.C.,University of Veracruz | Padilla-Sosa P.,University of Veracruz | Basurto- Pensado M.A.,Autonomous University of Mexico State | And 3 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2013

An optical fiber trap operates by radiation pressure and transverse force gradient while conventional optical trap operates on longitudinal gradient to trap particles. This subtle difference translates into easy setup and many advantages over conventional single-beam optical tweezers. In this work, we present a brief review of the current situation of fiber optic trap and their applications. Subsequently, we discuss the effect of radiation pressure on micro-organic and inorganic particles. Using a single optical fiber, radiation pressure transfers movement to the micro-particles, so velocity and acceleration are quantified. After that, micro particles are trapped, but now using two optical fibers. Finally, we discuss the results and problems involved with this research. © 2013 SPIE.


Golikov V.,UNACAR | Lebedeva O.,UNACAR | Castillejos-Moreno A.,IPN | Ponomaryov V.,IPN
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences | Year: 2011

This Letter presents the matched subspace detection in the presence of Gaussian background with known covariance structure but different variance for hypothesis H0 and H1. The performance degradation has been evaluated when there are the following mismatches between the actual and designed parameters: background variance in the case of hypothesis H1 and one-lag correlation coefficient of background. It has been shown that the detectability depends strongly on the fill factor of targets in the case of the mode signal matrix with high rank for a prescribed false alarm probability and a given signal-to-background ratio. These results have been also justified via Monte Carlo simulations for an example scenario. Copyright © 2011 The Institute of Electronics, Information and Communication Engineers.


Lebedeva O.,Autonomous University of Carmen | Martinez Vera E.,UNACAR | Golikov V.,Autonomous University of Carmen | Rodriguez Blanco M.,Autonomous University of Carmen
Proceedings - 2013 International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves, MSMW 2013 | Year: 2013

This work presents a novel generalized likelihood ratio (GLR) methodology to design a detection algorithm for a sequence of images in the presence of Gaussian structured background and noise. We focus on the detection of a subpixel target both with small target's energy and without it (dark target). It is assumed that the background power is known a priori under the null hypothesis and is unknown under the alternative hypothesis. This situation is typical in the case of subpixel detection. We derive the GLR test (GLRT) for this problem. The designed detector is theoretically justified and numerically evaluated. The structure of the designed detector consists of two detectors. The first detector is the known matched subspace detector and the second is the background's power change detector. The second detector help to detect the black subpixel targets (without reflected energy). Both the theoretical and computer simulation results have shown that the proposed detector outperforms the conventional one. © 2013 IEEE.


Leon B.S.,CINVESTAV | Alanis A.Y.,University of Guadalajara | Sanchez E.N.,CINVESTAV | Ruiz-Velazquez E.,University of Guadalajara | Ornelas-Tellez F.,UNACAR
International Journal of Adaptive Control and Signal Processing | Year: 2012

In this paper, a discrete-time inverse optimal trajectory tracking for a class of nonlinear positive systems is proposed. The scheme is developed for MIMO affine discrete-time positive nonlinear systems. This optimal controller is based on discrete time passivity and positive systems theory. The advantage of this scheme is that it avoids solving the associated Hamilton-Jacobi-Bellman equation and minimizes a meaningful cost function. The affine discrete-time positive nonlinear system is obtained from an online neural identifier, which uses a recurrent neural network, trained with the extended Kalman filter.The applicability of the proposed approach is illustrated via simulation by trajectory tracking control of type 1 diabetes mellitus patients. Copyright © 2012 John Wiley & Sons, Ltd.


Perez Alvis E.,UNACAR | Gonzalez Morales C.A.,PEMEX | Ortuno Maldonado E.,PEMEX | Espinosa Luna R.,Kelly Services
1st EAGE/ACGGP Latin American Geophysics Workshop | Year: 2012

Understanding the geological-structural environment through regional studies to characterize the velocity field from surface to reservoir has more geological sense. In Sonda de Campeche there are strong velocity variations in the Tertiary rocks that affect the shape and dimensions of structures in time (pull-up or pull-down). The study, modeling and understanding these effects help to propose the best solution and the best image in depth of the reservoir with time-depth conversion process. In this paper, we focus on detailing the interpretation around the fault zones (thrusts and growth faults) of events corresponding to carbonate rocks, to populate interval velocity models with which we obtain the time-depth conversion of the seismic data in the Sonda de Campeche. It was concluded that the seismic data require additional processes to improve the image of events in the shadow zone of faults. Finally, we performed 100 realizations of interval velocity models thus generated a probability distribution of the rock volume. This allows us to represent the uncertainty in the velocity field in areas where there is not well information.


Montoya-Hernandez D.J.,UNACAR | Vazquez-Hernandez A.O.,Mexican Institute of Petroleum | Cuamatzi R.,Mexican Institute of Petroleum | Hernandez M.A.,Mexican Institute of Petroleum
Ocean Engineering | Year: 2014

Marine risers are subjected to several types of excitation loads, such as motions induced by the floating production system, external hydrodynamics forces due to currents and waves and internal forces due to the internal fluid flow regularly composed by water, oil and gas. When internal flow conditions as pressure, temperature and flow rate fluctuations appear in a riser, they can induce vibration motion to the system. This paper shows a numerical algorithm to evaluate the vibrations of vertical rigid production risers under internal multiphase flow behavior. The numerical algorithm developed computes the natural frequencies of vertical risers model coupled with a hydrodynamic numerical model. The internal flow was composed of water, oil and gas and was treated as a pseudo-single phase (mixture). The numerical algorithm was developed using difference finite method. The results were compared with information available in the literature. © 2014 Elsevier Ltd. All rights reserved.


Golikov V.,UNACAR | Lebedeva O.,UNACAR | Moreno C.,National Polytechnic Institute of Mexico | Ponomaryov V.,National Polytechnic Institute of Mexico
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences | Year: 2011

This work extends the optimum Neymann-Pearson methodology to detection of a subspace signal in the correlated additive Gaussian noise when the noise power may be different under the null (H0) and alternative (H1) hypotheses. Moreover, it is assumed that the noise covariance structure and power under the null hypothesis are known but under the alternative hypothesis the noise power can be unknown. This situation occurs when the presence of a small point (subpixel) target decreases the noise power. The conventional matched subspace detector (MSD) neglects this phenomenon and causes a consistent loss in the detection performance. We derive the generalized likelihood ratio test (GLRT) for such a detection problem comparing it against the conventional MSD. The designed detector is theoretically justified and numerically evaluated. Both the theoretical and computer simulation results have shown that the proposed detector outperforms the conventional MSD. As to the detection performance, it has been shown that the detectivity of the proposed detector depends on the additional adaptive corrective term in the threshold. This corrective term decreases the value of presumed threshold automatically and, therefore, increases the probability of detection. The influence of this corrective term on the detector performance has been evaluated for an example scenario. Copyright © 2011 The Institute of Electronics, Information and Communication Engineers.


Castillejos H.,National Polytechnic Institute of Mexico | Ponomaryov V.,National Polytechnic Institute of Mexico | Nino-De-Rivera L.,National Polytechnic Institute of Mexico | Golikov V.,UNACAR
Computational and Mathematical Methods in Medicine | Year: 2012

This paper presents a novel approach to segmentation of dermoscopic images based on wavelet transform where the approximation coefficients have been shown to be efficient in segmentation. The three novel frameworks proposed in this paper, W-FCM, W-CPSFCM, and WK-Means, have been employed in segmentation using ROC curve analysis to demonstrate sufficiently good results. The novel W-CPSFCM algorithm permits the detection of a number of clusters in automatic mode without the intervention of a specialist. © 2012 Heydy Castillejos et al.


Golikov V.,UNACAR | Lebedeva O.,UNACAR
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences | Year: 2011

This work extends the constant false alarm rate (CFAR) detection methodology to detection in the presence of two independent interference sources with unknown powers. The proposed detector is analyzed on the assumption that clutter and jammer covariance structures are known and have relatively low rank properties. The limited-dimensional subspace-based approach leads to a robust false alarm rate (RFAR) detector. The RFAR detection algorithm is developed by an adaptation and extension of Hotelling's principal-component method. The detector performance loss and false alarm stability loss to unknown clutter and jammer powers have been evaluated for example scenario. Copyright © 2011 The Institute of Electronics, Information and Communication Engineers.


Victor G.,UNACAR | Marco R.B.,UNACAR | Manuel M.A.,UNACAR | Olga L.,UNACAR | And 2 more authors.
2014 11th International Conference on Electrical Engineering, Computing Science and Automatic Control, CCE 2014 | Year: 2014

The optical subpixel detection of the floating objects on an agitated sea surface remains a hard problem. In this paper, we conduct a comparative study and investigate the relationship between two techniques in image sequence detection: Well-known matched subspace detection (MSD) and recently proposed modified MSD (MMSD). MMSD approach extends the optimum Neyman-Pearson methodology to detection of a subspace signal in correlated additive Gaussian background when the background power may be different under the null (H0) and alternative (H1) hypotheses. It is assumed that the background covariance structure and power under the null hypothesis are known but under the alternative hypothesis the background power can be unknown. This situation occurs in optical systems when the presence of a small point (subpixel) object decreases the background power. The proposed detector structure contains the additional adaptive corrective term in the threshold. This corrective term decreases the value of presumed threshold automatically and, therefore, increases the probability of detection. Computer simulation and experimental results have shown that the proposed detector outperforms the conventional MSD. The influence of the adaptive threshold on the detector performance has been evaluated for the example scenario of the subpixel floating object on the agitated sea surface by using the experimental and simulation results. © 2014 IEEE.

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