The Sonora Institute of Technology is a Mexican public university based in Ciudad Obregón, Sonora, with satellite campuses in Guaymas and Navojoa. Founded in 1955 as a preparatory school called Justo Sierra Institute , it was initially sponsored by Lions International until 1956, when it renamed as Northwestern Institute of Technology . In 1962, Governor Luis Encinas Johnson approved a state law that restructured the institution and gave it its current name. Wikipedia.
Plaut J.A.,University of New Mexico |
Wadsworth W.D.,Rice University |
Pangle R.,University of New Mexico |
Yepez E.A.,Sonora Institute of Technology |
And 2 more authors.
New Phytologist | Year: 2013
Summary: Global climate change is predicted to alter the intensity and duration of droughts, but the effects of changing precipitation patterns on vegetation mortality are difficult to predict. Our objective was to determine whether prolonged drought or above-average precipitation altered the capacity to respond to the individual precipitation pulses that drive productivity and survival. We analyzed 5 yr of data from a rainfall manipulation experiment in piñon-juniper (Pinus edulis-Juniperus monosperma) woodland using mixed effects models of transpiration response to event size, antecedent soil moisture, and post-event vapor pressure deficit. Replicated treatments included irrigation, drought, ambient control and infrastructure control. Mortality was highest under drought, and the reduced post-pulse transpiration in the droughted trees that died was attributable to treatment effects beyond drier antecedent conditions and reduced event size. In particular, trees that died were nearly unresponsive to antecedent shallow soil moisture, suggesting reduced shallow absorbing root area. Irrigated trees showed an enhanced response to precipitation pulses. Prolonged drought initiates a downward spiral whereby trees are increasingly unable to utilize pulsed soil moisture. Thus, the additive effects of future, more frequent droughts may increase drought-related mortality. © 2013 New Phytologist Trust.
Bernal M.,Sonora Institute of Technology |
Sala A.,Polytechnic University of Valencia |
Jaadari A.,University of Valenciennes and Hainaut‑Cambresis |
Guerra T.-M.,University of Valenciennes and Hainaut‑Cambresis
Fuzzy Sets and Systems | Year: 2011
In this paper, the stability of continuous-time polynomial fuzzy models by means of a polynomial generalization of fuzzy Lyapunov functions is studied. Fuzzy Lyapunov functions have been fruitfully used in the literature for local analysis of Takagi-Sugeno models, a particular class of the polynomial fuzzy ones. Based on a recent Taylor-series approach which allows a polynomial fuzzy model to exactly represent a nonlinear model in a compact set of the state space, it is shown that a refinement of the polynomial Lyapunov function so as to make it share the fuzzy structure of the model proves advantageous. Conditions thus obtained are tested via available SOS software. © 2011 Elsevier B.V. All rights reserved.
Guerra T.M.,University of Valenciennes and Hainaut‑Cambresis |
Bernal M.,Sonora Institute of Technology
International Journal of Fuzzy Systems | Year: 2012
An original solution to overcome infeasible global quadratic conditions for stability of continuous-time nonlinear models via a Takagi-Sugeno (TS) representation has recently appeared. By changing the paradigm of global stability for something less restrictive a nice solution providing an estimation of the stability domain (local asymptotic conditions) is found, as it is usually the case for nonlinear models for which stability and/or stabilization cannot be reached globally. Strategies to get better estimations with lower computational cost are hereby presented to fully exploit the new approach; some hard nonlinear problems are thus systematically solved. Since the proposed conditions are expressed as linear matrix inequalities (LMIs) they can be efficiently solved by convex optimization techniques. Illustrative examples are provided to show the efficiency of the new technique which outperforms available stability analysis by escaping the quadratic framework. © 2012 TFSA.
Guerra T.M.,University of Valenciennes and Hainaut‑Cambresis |
Bernal M.,Sonora Institute of Technology |
Guelton K.,University of Reims Champagne Ardenne |
Labiod S.,Jijel University
Fuzzy Sets and Systems | Year: 2012
This paper is concerned with non-quadratic stabilization of continuous-time Takagi-Sugeno (TS) models. The well-known problem of handling time-derivatives of membership functions (MFs) as to obtain conditions in the form of linear matrix inequalities (LMIs) is overcome by reducing global goals to the estimation of a region of attraction. Instead of parallel distributed compensation (PDC), a non-PDC control law is proposed according to the non-quadratic nature of the Lyapunov function. Examples are provided to show the advantages over the quadratic and some non-quadratic approaches. © 2011 Elsevier B.V. All rights reserved.
Ruelas J.,Sonora Institute of Technology |
Velazquez N.,Autonomous University of Baja California |
Cerezo J.,Autonomous University of Baja California
Applied Energy | Year: 2013
This study develops and applies a new mathematical model for estimating the intercept factor of a Scheffler-type solar concentrator (STSC) based on the geometric and optical behaviour of the concentrator in Cartesian coordinates, and the incorporation of a thermal model of the receptor is performed using numerical examinations to determine the technical feasibility of attaching the STSC to a 3. kWe Stirling engine. A numerical validation of the mathematical model is determined based on the experimental results reported for the WGA500 concentrator and the CNRS-PROMES system receiver. The numerical results allow for the design of the STSC and a comparison with a parabolic dish that provides the same thermal demand. Our findings show that the highest concentration was obtained with an edge angle of 45°, which was observed in the parabolic dish as well, but the STSC receiver shows a 7% increase in the thermal efficiency compared with the efficiency of the parabolic dish receiver. Finally, the STSC is appropriate for regions where the solar height allows for a reduction of convective thermal loss. © 2012 Elsevier Ltd.
Loukianov A.G.,National Polytechnic Institute of Mexico |
Canedo J.M.,National Polytechnic Institute of Mexico |
Fridman L.M.,National Autonomous University of Mexico |
Soto-Cota A.,Sonora Institute of Technology
IEEE Transactions on Industrial Electronics | Year: 2011
This paper deals with the design of robust regulation for both angular speed stability enhancement and voltage in synchronous generator machines with an excitation control system. The designed controller is based on the block control technique combined with a sliding-mode (SM) control approach. The block control is used to design a nonlinear sliding manifold with the desired stability property. In order to attenuate the chattering effect which can appear in the presence of the exciter's unmodeled dynamics, a high-order SM algorithm and a robust exact differentiator are employed. The efficiency of the proposed controller, i.e., robustness and high accuracy, is verified via simulations. © 2006 IEEE.
Zaviska F.,University of Québec |
Drogui P.,University of Québec |
Pablo G.,Sonora Institute of Technology
Desalination | Year: 2012
This study examines the possibility to optimally produce active chlorine from a synthetic concentrate of seawater by electrolysis using an experimental design methodology. Different operating parameters were investigated such as current density, reaction time, hydrochloric acid concentration and chloride ion concentration. Using a 2 4 factorial matrix, the best performance for active chlorine production (46mg/l of HClO) was obtained at a current intensity of 1.6A during 35min of treatment time in the presence of 0.11M of H 3O + and 0.8M of NaCl. The current intensity and treatment time were the main parameters influencing the active chlorine production. Subsequently, a central composite design methodology has been investigated to determine the optimal experimental parameters for chlorine production. The electrolytic cell applied under optimal conditions (at a current intensity of 1.6A during 27min in the presence of 0.11M of NaCl and 0.8M of H 3O +) is able to produce 31mg/l of chlorine for an energy consumption of 0.54kWh/m 3. © 2012 Elsevier B.V.
Rodriguez L.-F.,Sonora Institute of Technology |
Cognitive Computation | Year: 2014
It has been recognized that human behavior is an observable consequence of the interactions between cognitive and affective functions. This perception has motivated the study of human emotions in disciplines such as psychology and neuroscience and led to the formulation of a number of theories and models that attempt to explain the mechanisms underlying this human process. In the field of artificial intelligence, these theoretical findings have posed a series of challenges in the development of autonomous agents (AAs) capable of exhibiting very believable and human-like behaviors. One of these challenges is the design and implementation of computational models of emotions (CMEs), which are software systems designed to provide AAs with proper mechanisms for the processing of emotional information, elicitation of synthetic emotions, and generation of emotional behaviors. In this paper, we review this type of computational model from the perspective of their development. Particularly, we investigate five design aspects that influence their development process: theoretical foundations, operating cycle, interaction between cognition and emotion, architectural design, and role in cognitive agent architectures. We provide discussions about key issues and challenges in the development of CMEs and suggest research that may lead to more robust and flexible designs for this type of computational model. © 2014 Springer Science+Business Media New York.
Martinez C.M.,San Luis Potosí Institute of Scientific Research and Technology |
Alvarez L.H.,Sonora Institute of Technology |
Celis L.B.,San Luis Potosí Institute of Scientific Research and Technology |
Cervantes F.J.,San Luis Potosí Institute of Scientific Research and Technology
Applied Microbiology and Biotechnology | Year: 2013
Humus constitutes a very abundant class of organic compounds that are chemically heterogeneous and widely distributed in terrestrial and aquatic environments. Evidence accumulated during the last decades indicating that humic substances play relevant roles on the transport, fate, and redox conversion of organic and inorganic compounds both in chemically and microbially driven reactions. The present review underlines the contribution of humus-reducing microorganisms in relevant environmental processes such as biodegradation of recalcitrant pollutants and mitigation of greenhouse gases emission in anoxic ecosystems, redox conversion of industrial contaminants in anaerobic wastewater treatment systems, and on the microbial production of nanocatalysts and alternative energy sources. © Springer-Verlag Berlin Heidelberg 2013.
Lares-Jimenez L.F.,Sonora Institute of Technology |
Gamez-Gutierrez R.A.,Sonora Institute of Technology |
Lares-Villa F.,Sonora Institute of Technology
Diagnostic Microbiology and Infectious Disease | Year: 2015
Until now, for axenic cultivation of Balamuthia mandrillaris, the BM-3 culture medium and the Modified Chang's special medium have been the only ones recommended, but they have some disadvantages, as both require many components and their preparations are laborious. Therefore, we developed a novel culture medium for B. mandrillaris axenic cultivation. Each one of the 11 components of BM-3 was combined with Cerva's medium as basal culture medium. Ten strains of B. mandrillaris including the reference strain CDC:V039 and 9 environmental isolates were used during trials. After testing all combinations, the basal medium complemented with 10× Hank's balanced salt solution was the only one that supported confluent growth of B. mandrillaris. Cell shape and motility of trophozoites were normal. This developed medium is as useful as BM-3 for axenization. The development of a cheaper and easy-to-prepare medium for B. mandrillaris opens the possibility of increasing its study. © 2015 Elsevier Inc.