Optimización de la producción de un invernadero mediante control predictivo no lineal

Consultable des del TDXTítol obtingut de la portada digitalitzadaEn la presente tesis se presenta una aplicación práctica del control predictivo sobre un invernadero real. Por esta razón se desarrolla un algoritmo de control predictivo MELPC, no lineal, multivariable, basado en la linealización en línea y que no requiere un gran esfuerzo computacional. La investigación se ha centrado en el comportamiento de este controlador tanto en rendimiento como en aspectos computacionales. Se ha incluido, además, el análisis de un amplio rango de problemas relacionados con el control de sistemas con restricciones, tales como: estabilidad, factibilidad, optimización, implementación y cálculo, e influencia de las perturbaciones. Este estudio se ha complementado con una comparación entre los diferentes algoritmos que usan la misma técnica de linealización on-line ELPC, EPSAC y también con los algoritmos de control predictivo lineal y no lineal. También se han expuesto una serie de experimentos en simulaciones para probar el MELPC, controlador elaborado en esta tesis. Los experimentos consisten en aplicar este controlador sobre una amplia gama de sistemas con dinámicas diferentes. Finalmente se ha aplicado este controlador sobre un invernadero real construido en el Institute for Horticultural and Agricultural Engineering ITG de la Universidad de Hannover (Alemania) para el control de las variables clim ticas en tiempo real. Se ha desarrollado un modelo de invernadero real similar a los sistemas de producción en la industria agrícola, considerando las variables de estado: temperatura interna, humedad interna y concentración de CO2. También se ha presentado el modelo de crecimiento del cultivo que es la lechuga porque es un modelo sencillo con pocas variables de estado y que son: el peso seco no-estructural y el peso seco estructural.This work present a practical application of the predictive control on a real greenhouse. For this reason a predictive control algorithm MELPC is developed, This algorithm has the characteristics that is nonlinear, multivariable, based on the linearization and that does not require a great computational burden. He investigation has been centred in the behaviour of this controller as much in performance as in computational aspects. In addition, an analysis of an ample rank of problems related to the control of systems with restrictions is included, such as: stability, feasibility, optimisation, implementation and calculation, and influence of the disturbances. This study has been complemented with a comparison between the different algorithms that use the same technique of linealization online ELPC, EPSAC and also with the algorithms of linear and nonlinear predictive control. Also a series of experiments in simulations has been exposed to test the MELPC, controller elaborated in this thesis. The experiments consist of applying this controller on an ample range of systems with different dynamics. Finally this controller has been applied on a real greenhouse constructed in the Institute of Horticultural and Agricultural Engineering ITG of the University of Hannover (Germany) for the control of the climatic variables. A model of real greenhouse similar to the production systems in the agricultural industry has been developed, considering the state variables: internal temperature, internal humidity and CO2 concentration. Also a growth model of the culture is presented that is the lettuce

Progesterone Synthesis in the Nervous System: Implications for Myelination and Myelin Repair

Progesterone is well known as a female reproductive hormone and in particular for its role in uterine receptivity, implantation, and the maintenance of pregnancy. However, neuroendocrine research over the past decades has established that progesterone has multiple functions beyond reproduction. Within the nervous system, its neuromodulatory and neuroprotective effects are much studied. Although progesterone has been shown to also promote myelin repair, its influence and that of other steroids on myelination and remyelination is relatively neglected. Reasons for this are that hormonal influences are still not considered as a central problem by most myelin biologists, and that neuroendocrinologists are not sufficiently concerned with the importance of myelin in neuron functions and viability. The effects of progesterone in the nervous system involve a variety of signaling mechanisms. The identification of the classical intracellular progesterone receptors as therapeutic targets for myelin repair suggests new health benefits for synthetic progestins, specifically designed for contraceptive use and hormone replacement therapies. There are also major advantages to use natural progesterone in neuroprotective and myelin repair strategies, because progesterone is converted to biologically active metabolites in nervous tissues and interacts with multiple target proteins. The delivery of progesterone however represents a challenge because of its first-pass metabolism in digestive tract and liver. Recently, the intranasal route of progesterone administration has received attention for easy and efficient targeting of the brain. Progesterone in the brain is derived from the steroidogenic endocrine glands or from local synthesis by neural cells. Stimulating the formation of endogenous progesterone is currently explored as an alternative strategy for neuroprotection, axonal regeneration, and myelin repair

Architectural design of trust based recommendation system in customer relationship management

Most Companies are more customer centric than they were before. By adopting this strategy, it made the electronic commerce growing and enhance buyers experience. from the other side, Companies started to explore this customer experience -data generated- to extract knowledge about their customer to be well managed – eCRM - instead of classic customer relationship Management - CRM. Large quantity of Data motivated the companies to look for changes, and ask for more functionality, and this are what influenced software editors to adapt their solutions and implement the power of data. Nowadays, data available – Big Data – put the existing systems and architectures under question and push us to rethink the logical layer to explore this data. Following the data vague, puts a need to reconsider and study the strength of eCRM/CRM existing solutions and architectures. The main contribution of this paper is to propose architecture built on Trust-Based recommendation able to provide to companies better accuracy, coverage, novelty and diversity during the sales process

Limited effects of preterm birth and the first enteral nutrition on cerebellum morphology and gene expression in piglets

Preterm pigs show many signs of immaturity that are characteristic of preterm infants. In preterm infants, the cerebellum grows particularly rapid and hypoplasia and cellular lesions are associated with motor dysfunction and cognitive deficits. We hypothesized that functional brain delays observed in preterm pigs would be paralleled by both structural and molecular differences in the cerebellum relative to term born piglets. Cerebella were collected from term (n=56) and preterm (90% gestation, n=112) pigs at 0, 5, and 26days after birth for stereological volume estimations, large-scale qPCR gene expression analyses (selected neurodevelopmental genes) and western blot protein expression analysis (Sonic Hedgehog pathway). Memory and learning was tested using a T-maze, documenting that preterm pigs showed delayed learning. Preterm pigs also showed reduced volume of both white and gray matter at all three ages but the proportion of white matter increased postnatally, relative to term pigs. Early initiation of enteral nutrition had limited structural or molecular effects. The Sonic Hedgehog pathway was unaffected by preterm birth. Few differences in expression of the selected genes were found, except consistently higher mRNA levels of Midkine, p75, and Neurotrophic factor 3 in the preterm cerebellum postnatally, probably reflecting an adaptive response to preterm birth. Pig cerebellar development appears more affected by postconceptional age than by environmental factors at birth or postnatally. Compensatory mechanisms following preterm birth may include faster white matter growth and increased expression of selected genes for neurotrophic factors and regulation of angiogenesis. While the pig cerebellum is immature in 90% gestation preterm pigs, it appears relatively mature and resilient toward environmental factor

Myelinated, synapsing cultures of murine spinal cord – validation as an in vitro model of the central nervous system

Research in central nervous system (CNS) biology and pathology requires in vitro models, which, to recapitulate the CNS in vivo, must have extensive myelin and synapse formation under serum-free (defined) conditions. However, finding such a model has proven difficult. The technique described here produces dense cultures of myelinated axons, with abundant synapses and nodes of Ranvier, that are suitable for both morphological and biochemical analysis. Cellular and molecular events were easily visualised using conventional microscopy. Ultrastructurally, myelin sheaths were of the appropriate thickness relative to axonal diameter (G-ratio). Production of myelinated axons in these cultures was consistent and repeatable, as shown by statistical analysis of multiple experimental repeats. Myelinated axons were so abundant that from one litter of embryonic mice, myelin was produced in amounts sufficient for bulk biochemical analysis. This culture method was assessed for its ability to generate an in vitro model of the CNS that could be used for both neurobiological and neuropathological research. Myelin protein kinetics were investigated using a myelin fraction isolated from the cultures. This fraction was found to be superior, quantitatively and qualitatively, to the fraction recovered from standard cultures of dissociated oligodendrocytes, or from brain slices. The model was also used to investigate the roles of specific molecules in the pathogenesis of inflammatory CNS diseases. Using the defined conditions offered by this culture system, dose-specific, inhibitory effects of inflammatory cytokines on myelin formation were demonstrated, unequivocally. The method is technically quick, easy and reliable, and should have wide application to CNS research

Netrin-1 acts as a survival factor for aggressive neuroblastoma

Neuroblastoma (NB), the most frequent solid tumor of early childhood, is diagnosed as a disseminated disease in >60% of cases, and several lines of evidence support the resistance to apoptosis as a prerequisite for NB progression. We show that autocrine production of netrin-1, a multifunctional laminin-related molecule, conveys a selective advantage in tumor growth and dissemination in aggressive NB, as it blocks the proapoptotic activity of the UNC5H netrin-1 dependence receptors. We show that such netrin-1 up-regulation is a potential marker for poor prognosis in stage 4S and, more generally, in NB stage 4 diagnosed infants. Moreover, we propose that interference with the netrin-1 autocrine loop in malignant neuroblasts could represent an alternative therapeutic strategy, as disruption of this loop triggers in vitro NB cell death and inhibits NB metastasis in avian and mouse models

Fusion of metabolomics and proteomics data for biomarkers discovery: case study on the experimental autoimmune encephalomyelitis

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