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Finite-time continuous control for mechanical systems with bounded inputs

Griselda Ivone Zamora Gómez (2020)

"In this dissertation the design of finite-time/exponential continuous control schemes for mechanical systems with bounded inputs is presented. The work involves the recent theoretical framework of local homogeneity, which expands the design flexibility and it results to be fundamental to solve problems with constrained inputs. The proposed schemes include corrective actions on the position and velocity errors with generalized structures. Moreover, all the proposed schemes give the freedom to choose among finite-time and exponential convergence through a simple parameter. Under the considered analytical framework, the regulation problem is first studied for both cases: state-feedback and output-feedback. Further, the state-feedback motion control problem is studied, supporting the closed-loop system through a strict Lyapunov function. Subsequently, a robustness study is developed for the trajectory-tracking control, under the consideration of an input-matching bounded perturbation term. Such a study has permitted to conclude that for a perturbation term with sufficiently small bound, the error variable trajectories converge into an origin-centered ball whose radius becomes smaller in the finite-time convergence case, entailing smaller post-transient variations than in the exponential case. Moreover, this is shown to be achieved for any initial condition and avoiding to restrain any of the parameters involved in the control design. All the proposed controllers are further tested through simulation and experimental implementations."

"En esta tesis se presenta el diseño de esquemas continuos de control en tiempo nito o exponencial para sistemas mecánicos con entradas acotadas. El trabajo involucra el reciente marco teórico de la homogeneidad local, lo cual amplía la exibilidad de diseño y resulta fundamental para resolver los problemas formulados ante restricciones de entrada. Los esquemas propuestos involucran acciones de corrección en errores de posición y velocidad con estructuras generalizadas. Más aún, dan al usuario la posibilidad de elegir entre convergencia en tiempo nito y exponencial a través de un simple parámetro. En el contexto analítico considerado, se aborda primero el problema de regulación tanto por retroalimentación de estado como de salida. Después, se aborda el problema de control de movimiento por retroalimentación de estado, soportando el análisis en lazo cerrado a través de una función estricta de Lyapunov. Posteriormente, para el control de seguimiento de trayectorias, se realiza un estudio de robustez considerando un término de perturbación acotado que se añade a la entrada. Este estudio permite concluir que para un término de perturbación su ficientemente pequeño, las trayectorias de las variables de error convergen al interior de una bola con centro en el origen cuyo radio se vuelve más pequeño en el caso de la convergencia en tiempo nito, implicando variaciones post-transitorias más pequeñas que en el caso exponencial. Más aún, esto se cumple para cualquier condición inicial y evitando restringir cualquier parámetro involucrado en el diseño de control. Todos los controladores propuestos son implementados a través de simulaciones y experimentos."

Doctoral thesis

Finite-time continuous control Local homogeneity Robustness Mechanical systems Constrained inputs INGENIERÍA Y TECNOLOGÍA INGENIERÍA Y TECNOLOGÍA

Structural modification of waste materials and its use in building materials

GONZALO MARTINEZ BARRERA GENCEL OSMAN (2015)

This chapter is divided into three sections, in the first one the modifications of waste materials by using gamma radiation are described; such materials are PET bottles, Tetra Pak packages and rubber tires. The second section describes the effects of these waste materials on the mechanical properties of concrete; and in the last section those effects provoked by gamma radiation in concrete containing these waste materials.

Book part

Waste materials Building materials Gamma radiation Mechanical properties INGENIERÍA Y TECNOLOGÍA

Reconfiguración incremental de sensores en la instrumentación de un calorímetro no-convencional

MARTHA CECILIA ARELLANO ALAMILLA (2020)

En la era de la tecnología, estamos observando cambios revolucionarios en nuestra manera de vivir, debido a la automatización de cualquier proceso, lo que nos vuelve cada vez más dependientes de la tecnología. Sin embargo, en la medida que incrementamos el uso de los dispositivos tecnológicos, mayoritariamente electrónicos, el problema de transferencia de calor crece de igual manera, además de ser este último un tema bastante desatendido. En este tenor, las necesidades mundiales de sistemas digitales complejos son cada día mayores, lo que da lugar a una excesiva generación de potencia térmica por efecto Joule. En últimas, contaminación. Por esta razón, es importante el desarrollo de sistemas contables con el objeto de cuantificar el impacto de este efecto térmico en nuestros dispositivos electrónicos y en el ambiente. En este trabajo de tesis se aborda el problema de instrumentación de un calorímetro no-convencional con el objetivo de mejorar su sensibilidad y, a su vez, la precisión en la medición de sus sensores. Las modificaciones propuestas permiten tener una mejor medición en la determinación experimental del flujo de calor generado por circuitos electrónicos. Las estrategias más importantes desarrolladas comprenden el ajuste de posición e incremento de sensores de manera experimental. Simultáneamente, se revisa y mejora el modelo matemático, con base en herramientas del cálculo fraccionario, utilizando resultados experimentales.

In the era of technology, we are observing revolutionary changes in daily life due to the automatization of any process, and we are becoming dependent on technology. However, as we increase the use of technology, the problem of heat transfer in electronic devices also grows besides being a subject very neglected. In such a tier, the world requirements of complex digital systems have been increased each day, generating heat substantially by the Joule effect. Namely, pollution. Therefore, it is crucial to develop reliable systems

to quantify the impact of the thermal effect on electronic devices. In this thesis, the instrumentation problem of a non-conventional calorimeter is addressed to increase the sensitivity and, simultaneously, the sensors’ precision. The proposed modification allows enhancing measurements in the experimental determination of heat dissipated by electronic circuits. Essential strategies are considered for rearranging and increasing heat sensors in the experimental setup. Simultaneously, a mathematical model is developed by using foundations from fractional calculus to improve the forecast of experimental results.

Master thesis

CIS- Maestría en Ingeniería Eléctrica (Instrumentación y Sistemas Digitales) INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE LA INSTRUMENTACIÓN Calorímetro no-convencional – Instrumentación Sensores – Reconfiguración incremental Sistemas digitales Circuitos electrónicos – Generación de calor Non-conventional calorimeter – Instrumentation Sensors - Incremental reconfiguration Digital systems Electronic circuits - Heat generation

CYP450 Genotype/Phenotype Concordance in Mexican Amerindian Indigenous Populations–Where to from Here for Global Precision Medicine?

BLANCA PATRICIA LAZALDE RAMOS (2017)

Global precision medicine demands characterization of drug metabolism and phenotype variation in diverse populations, including the indigenous societies. A related question is the extent to which CYP450 drug metabolizing enzyme genotype and phenotype data are concordant and whether they can be used interchangeably. These issues are increasingly debated as precision medicine continues to expand as a popular research topic worldwide. We report here the first study in clinically relevant CYP450 drug metabolism phenotypes and genotypes in Mexican Amerindian indigenous subjects. In a large sample of 450 unrelated and medication free Mexican Amerindian indigenous healthy persons from four Mexican states (Chihuahua, Durango, Nayarit, and Sonora), we performed multiplexed phenotyping for the CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 drug metabolizing enzymes using the CEIBA cocktail and genotyped the same pathways for functional polymorphic variation. Remarkable interindividual variability was found for the actual drug metabolizing capacity of all the enzymes analyzed, and, more specifically, the metabolic ratios calculated were significantly different across individuals with different number of active alleles for CYP2C9, CYP2C19, and CYP2D6. The drug metabolizing capacity "predicted" from the genotype determined was not in accordance with the actual capacity "measured" by phenotyping in several individuals for CYP2C9, CYP2C19, and CYP2D6. Consequently, a more extensive genotyping of the main CYP enzymes, including rare variants, together with the analysis of the actual drug metabolizing capacity using an appropriate phenotyping approach will add valuable information for accurate drug metabolism studies, especially useful in understudied populations such as Mexican Amerindians. In sum, this study demonstrates that current personalized medicine strategies based on "predicted" phenotype from genotyping of alleles with high frequency in European populations are not adequate for Mestizos and Native American populations.

Producción Científica de la Universidad Autónoma de Zacatecas UAZ

Article

BIOLOGÍA Y QUÍMICA biomarkers developing world omics drug metabolism variation global personalized medicine systems diagnostics