Time filter

Source Type

Sandoval J.,Technological Institute of La Paz | Kelly R.,CICESE | Santibanez V.,Technological Institute of La Laguna
2015 European Control Conference, ECC 2015 | Year: 2015

The Controlled Lagrangian method is a strategy for the design of control systems for a class of Lagrangian systems. This method has resolved the stabilization problem of some well-known underactuated mechanical systems, including an inverted pendulum on a force-driven cart benchmark. This paper goes deeply into the analysis of this control system by studying in detail asymptotic stability invoking the Barbashin-Krasovskii's theorem and giving an explicit novel estimate of the domain of attraction. As a consequence, an estimate of the domain of attraction that resolves the practical motivated issue of maintaining the travel of the cart within prescribed physical limits of displacement is obtained. Numerical simulations are presented to illustrate these results. © 2015 EUCA.

Background: Crassostrea gigas accumulates diarrheic shellfish toxins (DSP) associated to Prorocentrum lima of which Okadaic acid (OA) causes specific inhibitions of serine and threonine phosphatases 1 and 2A. Its toxic effects have been extensively reported in bivalve mollusks at cellular and physiological levels, but genomic approaches have been scarcely studied. Methodology/ Principal Findings: Acute and sub-chronic exposure effects of P. lima were investigated on farmed juvenile C. gigas (3-5 mm). The Pacific oysters were fed with three dinoflagellate concentrations: 0.3, 3, and 30×103 cells mL-1 along with a nontoxic control diet of Isochrysis galbana. The effects of P. lima on C. gigas were followed by analyzing expression levels of a total of four genes, three involved in cell cycle regulation and one in immune response by polymerase chain reaction and real time quantitative PCR, where changes in time and cell concentration were found. The highest expression levels were found in oysters fed 3×103 cells mL-1 at 168 h for the cycle regulator p21 protein (9 fold), chromatin assembly factor 1 p55 subunit (8 fold), elongation factor 2 (2 fold), and lipopolysaccharide/ β-1, 3 glucan binding protein (13 fold above base line). Additionally, the transcript level of all the genes decreased in oysters fed wich the mixed diet 30×103 cells mL-1 of dinoflagellate after 72 h and was lowest in the chromatin assembly factor 1 p55 subunit (0.9 fold below baseline). Conclusions: On C. gigas the whole cell ingestion of P lima caused a clear mRNA modulation expression of the genes involved in cell cycle regulation and immune system. Over-expression could be related to DNA damage, disturbances in cell cycle continuity, probably a genotoxic effect, as well as an activation of its innate immune system as first line of defense. © 2014 de Jesús Romero-Geraldo et al.

De-Leon Almaraz S.,R.A.U.M. | Azzaro-Pantel C.,R.A.U.M. | Montastruc L.,R.A.U.M. | Pibouleau L.,R.A.U.M. | Senties O.B.,Technological Institute of La Paz
International Journal of Hydrogen Energy | Year: 2013

This work considers the potential future use of hydrogen in fuel cell electrical vehicles to face problems such as global warming, air pollution, energy security and competitiveness. The lack of current infrastructure has been identified as one of the main barriers to develop the hydrogen economy. This work is focused on the design of a hydrogen supply chain through mixed integer linear programming used to find the best solutions for a multi-objective optimization problem in which three objectives are involved, i.e., cost, global warming potential and safety risk. This problem is solved by implementing an É-constraint method. The solution consists of a Pareto front, corresponding to different design strategies in the associated variable space. Multiple choice decision making is then recommended to find the best solution through an M-TOPSIS analysis. The model is applied to the Great Britain case study previously treated in the dedicated literature. Mono and multicriteria optimizations exhibit some differences concerning the degree of centralization of the network and the selection of the production technology type. © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.

Background:Crassostrea gigas accumulates paralytic shellfish toxins (PST) associated with red tide species as Gymnodinium catenatum. Previous studies demonstrated bivalves show variable feeding responses to toxic algae at physiological level; recently, only one study has reported biochemical changes in the transcript level of the genes involved in C. gigas stress response.Principal Findings:We found that 24 h feeding on toxic dinoflagellate cells (acute exposure) induced a significant decrease in clearance rate and expression level changes of the genes involved in antioxidant defense (copper/zinc superoxide dismutase, Cu/Zn-SOD), cell detoxification (glutathione S-transferase, GST and cytochrome P450, CPY450), intermediate immune response activation (lipopolysaccharide and beta glucan binding protein, LGBP), and stress responses (glutamine synthetase, GS) in Pacific oysters compared to the effects with the non-toxic microalga Isochrysis galbana. A sub-chronic exposure feeding on toxic dinoflagellate cells for seven and fourteen days (30×103 cells mL-1) showed higher gene expression levels. A significant increase was observed in Cu/Zn-SOD, GST, and LGBP at day 7 and a major increase in GS and CPY450 at day 14. We also observed that oysters fed only with G. catenatum (3×103 cells mL-1) produced a significant increase on the transcription level than in a mixed diet (3×103 cells mL-1 of G. catenatum+0.75×106 cells mL-1 I. galbana) in all the analyzed genes.Conclusions:Our results provide gene expression data of PST producer dinoflagellate G. catenatum toxic effects on C. gigas, a commercially important bivalve. Over expressed genes indicate the activation of a potent protective mechanism, whose response depends on both cell concentration and exposure time against these toxic microalgae. Given the importance of dinoflagellate blooms in coastal environments, these results provide a more comprehensive overview of how oysters respond to stress generated by toxic dinoflagellate exposure. © 2013 García-Lagunas et al.

Barranco-Gutierrez A.I.,Technological Institute of La Paz | Martinez-Diaz S.,Technological Institute of La Paz | Gomez-Torres J.L.,Technological Institute of La Paz
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

In this work, we propose an approach for utility pole recognition in real conditions based on color, shape and photometric stereo vision, by using conventional low cost cameras. This subsystem is part of an automatic path planning system for a maintenance robot, which repairs the cable connections in electrical poles. This method could be used in applications requiring object recognition in outdoor environments. The challenges facing this approach include extreme solar illumination, the confusion between telephone poles, cable TV, in columns of buildings, trees, street lights, and tilt between the ground and the pole. The experiments of this recognition system shows satisfactory results under different solar illuminations, different distances between the post and the cameras, different inclinations of pole with respect to the ground, occlusions of the pole and location of the utility pole from cameras system. Results were totally satisfactory with 100% effectiveness in a range of 5% to 95% with respect to the H component of the HSV scheme. The proposed method recognizes and locates utility poles with respect to the stereo vision system. © Springer-Verlag Berlin Heidelberg 2014.

Martinez-Diaz S.,Technological Institute of La Paz | Kober V.,CICESE
Proceedings - 2011 International Conference on Computational Science and Its Applications, ICCSA 2011 | Year: 2011

In literature several correlation filters have been proposed for image recognition. Traditionally linear correlation is applied among the images for this purpose, however, the operation is not robust when images are corrupted with non-Gaussian noise. In this paper we propose the use of morphological correlation combined with nonlinear filters for robust image recognition. Performance of the proposed technique is compared with that of classical linear filtering in terms of discrimination capability. Computer simulation results are provided and discussed. © 2011 IEEE.

Martinez-Diaz S.,Technological Institute of La Paz | Martinez-Chavelas S.,National Autonomous University of Mexico
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2014

Geometrical distortions are a major problem in image recognition. Composite correlation filters can be used for distortion-invariant image recognition by incorporating rotated versions of the target object. Traditionally composite filters are designed with linear techniques; but, these filters are sensitive to non-Gaussian noise. On the other hand, for the same purpose, composite nonlinear filters have been proposed too. These filters have a good discrimination capability and they are robust to non-Gaussian noise and illumination changes; however, the performance of filter could be reduced when the number of training images incorporated increases. In this paper, we propose a method for designing rotation-invariant composite nonlinear filters. The method tries to maximize the number of objects incorporated into the filter and preserve its performance. © Springer International Publishing Switzerland 2014.

Martinez-Diaz S.,Technological Institute of La Paz
Lecture Notes in Electrical Engineering | Year: 2013

Recently, nonlinear composite correlation filters have been proposed for distortion-invariant pattern recognition. The filter design is based on logical operations and the correlation is computed with a nonlinear operation called morphological correlation. In this paper a new implementation in parallel hardware of these kinds of filters for image recognition is proposed. The architecture is designed for a Field Programmable Gate Array (FPGA) device. The proposed design performs the most time consuming task of the recognition procedure. In consequence, it reduces the time required for the nonlinear operations in the spatial domain. Simulation results are provided and discussed. © 2013 Springer Science+Business Media Dordrecht.

Von Borstel F.D.,Engineering Group | Suarez J.,Technological Institute of La Paz | De La Rosa E.,Technological Institute of La Paz | Gutierrez J.,Engineering Group
Industrial Robot | Year: 2013

Purpose - The purpose of this paper is to develop a robotic system to feed aquatic organisms and measure water physicochemical parameters in experimental aquaculture ponds. Design/methodology/approach - A dispatcher unit dispenses a precise amount of food and control panel software schedules the tasks and operates the robot. In the control panel, the feeding and measuring schedule is defined and sent to the mobile robot and the amount of food is requested by the robot to the dispatcher for each pond. The robot travels automatically on a monorail to dispense the food and measure the water parameters. The data are transmitted to the control panel. The system can be remotely operated over the internet through a client-server software framework. Findings - The robotic system is a tool for delegating feeding and measuring tasks. This allows researchers and technicians time to focus on more substantive aquacultural research tasks. Research limitations/implications - Future improvement will include an automatic unit for cleaning sensors between ponds to minimize the risk of cross-contamination. Practical implications - The system systematized feeding and measuring tasks, minimized human error, and optimized the use of resources for aquacultural experimentation. The robotic system can be programmed for a variety of experimental conditions, such as the delivery of different diets at diverse schedules. Originality/value - The proposed robot was tested for feeding freshwater redclaw crayfish (Cherax quadricarinatus) and monitored the water parameters in real time. Based on the field results, the robotic system provided a reliable and robust device for aquacultural research applications.© Emerald Group Publishing Limited.

PubMed | National Polytechnic Institute of Mexico and Technological Institute of La Paz
Type: | Journal: Marine environmental research | Year: 2016

Bivalve mollusks bioaccumulate toxins via ingestion of toxic dinoflagellates. In this study, Crassostrea gigas was used to investigate the effects related to Prorocentrum lima exposure. Oysters were fed with three diets Isochrysis galbana (210(6)cellmL(-1)) control treatment; algal mix of I.galbana (210(6)) and P.lima (310(3)cellmL(-1)); and P.lima alone (310(3)cellmL(-1)). Feeding behavior changes, histopathological alterations, and expression patterns changes of genes involved in cell cycle (p21, cafp55, p53), cytoskeleton (tub, act), and inflammatory process (casp1) were evaluated. Results indicated that the presence of diarrheic shellfish poisoning by P.lima cells decreased the clearance rate (p<0.05), induced structural loss, significantly decreased tubule area of the digestive gland (p<0.05), and up-regulated in expression all gene (p<0.05), suggesting that toxic cells might trigger inflammatory tissue process, disturb cell cycle and cytoskeleton representing a risk to oysters integrity.

Loading Technological Institute of La Paz collaborators
Loading Technological Institute of La Paz collaborators