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1
artÃculo
Publicado 2023
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Understanding how the physiological processes of trees are affected by the environment or silvicultural practices is important for forest management, which requires process-based models. It enables the evaluation of the growth of a forest under different scenarios. The 3-PG model has been widely used all over the world, justified by its simplicity and efficiency, as it uses a more accessible language and fewer parameters than other process-based models. It is a model of greatest interest for forest management because it enables the use of allometric equations to calculate variables of interest in this area, such as the average diameter at 1.30 m height (DBH), total height and stand volume. The 3-PG parameterization is essential to guarantee the model's good performance; however, in some cases, when observed data are not available, values from the literature is used or calibration is perf...
2
tesis doctoral
Publicado 2021
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Descargue en el texto completo en el repositorio institucional de la Universidade Federal de Santa Catarina: https://repositorio.ufsc.br/handle/123456789/231074
3
artÃculo
Publicado 2022
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The real-time prediction and estimation of the spread of diseases, such as COVID-19 is of paramount importance as evidenced by the recent pandemic. This work is concerned with the distributed parameter estimation of the time–space propagation of such diseases using a diffusion–reaction epidemiological model of the susceptible–exposed–infected–recovered (SEIR) type. State estimation is based on continuous measurements of the number of infections and deaths per unit of time and of the host spatial domain. The observer design method is based on positive definite matrices to parameterize a class of Lyapunov functionals, in order to stabilize the estimation error dynamics. Thus, the stability conditions can be expressed as a set of matrix inequality constraints which can be solved numerically using sum of squares (SOS) and standard semi-definite programming (SDP) tools. The observer...
4
artÃculo
Publicado 2022
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This paper is concerned with the design of observers for a class of one-dimensional multi-state transport-reaction systems considering distributed in-domain measurements over the spatial domain. A design based on the Lyapunov method is proposed for the stabilization of the estimation error dynamics. The approach uses positive definite matrices to parameterize a class of Lyapunov functionals that are positive in the Lebesgue space of integrable square functions. Thus, the stability conditions can be expressed as a set of LMI constraints which can be solved numerically using sum of squares (SOS) and standard semi-definite programming (SDP) tools. In order to evaluate the proposed methodology, a state observer is designed to estimate the variables of a nonisothermal tubular reactor model. Numerical simulations are presented to demonstrate the potentials of the proposed observer.
5
artÃculo
Publicado 2021
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In this work, the modeling of the volatility of financial assets is studied using a Bayesian approach. DCC - GARCH models are used, for the errors of these models asymmetric and leptokurtic probability distributions are considered, which are parameterized according to the asymmetry and the weight of the tails, therefore these parameters are also estimated. The estimation of the model parameters was performed using the MCMC methodology Metropolis - Hastings random walk algorithm using the software R package bayesDccGarch, daily data from 04/01/2015 - 01/31/2020 of the stock indices of: Frankfurt are considered (DAX), Tokyo (NIKKEI225), Paris (CAC40), and Lima (BVL). The Bayesian approach to estimating the model parameters facilitates interpretation and provides the ability to insert a priori information for the parameters.
6
tesis de grado
Publicado 2024
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El diseño y construcción de embarcaciones es una industria que genera muchas divisas a un paÃs. La investigación en esta área está en continuo desarrollo a nivel mundial. Una de las áreas de investigación es la caracterización del estado de mar por el cual la embarcación navegará. En particular, el espectro de mar es un modelo matemático del mar que se utiliza para calcular las respuestas del buque, junto con el operador de amplitud de respuesta, RAO. El espectro de mar es variable en el tiempo y en el espacio, pero mantiene una caracterÃstica visible en un lapso de 20 minutos [21]. Obtener la curva real del espectro no es práctico ya que varÃa, entonces, el estado de mar se aproxima a uno parametrizado, con altura significativa y el periodo modal como parámetros principales. Estos parámetros son calculados de la data de elevación de ola obtenidos de las boyas oceánica...
7
tesis de grado
Publicado 2015
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Este proyecto tiene como objetivo la implementación de algoritmos para la detección de defectos en las telas poliéster. Como sabemos, desde sus inicios la industria ha utilizado avances tecnológicos no sólo para optimizar los procesos de fabricación sino también para mejorar la calidad de los productos. Ahora, si bien, no es posible evitar las fallas que alteran la calidad de las telas poliéster, sà es posible su detección mediante una inspección visual dentro del proceso de fabricación. En el presente estudio se realizó algoritmos de procesamiento de imágenes mediante el uso de librerÃas del software LabView para la detección de defectos en las telas poliéster, basándonos en muestras de telas con manchas comunes (MC), manchas de aceite (MA) y puntadas erróneas (PE), las cuales nos permitieron realizar varias pruebas experimentales, utilizando un módulo de pruebas a p...
8
tesis de grado
La ciudad de Lima está ubicada en una zona altamente sÃsmica categorizada según la (NTE E.030-Diseño Sismorresitente, 2018) como Z4 por ubicarse entre las placas Nazca y Sudamericana. En adición, esta región atraviesa un silencio sÃsmico desde 1746 que conllevarÃa a grandes pérdidas humanas y materiales ante un evento sÃsmico de gran magnitud en orden de 8.6- 8.8 Mw. basado en el estudio de modelos para futuros mega terremotos en la ciudad de Lima (Pulido, Aguilar, & Tavera, 2015). La presente investigación se desarrolló con la finalidad de conocer la respuesta dinámica de la estructura del paraboloide FIC-UNI ante vibraciones ambientales y fuerzas externas mediante la utilización del Operation Modal Analysis (OMA) que asume dicha respuesta como una combinación de modos de la estructura parametrizados por propiedades inherentes en estos, tales como: la frecuencia natural, ...
9
tesis de maestrÃa
We consider a beyond standard physics scenario, where neutrino is considered as an open quantum system. In order to have that consideration we use the Lindblad master equation, which introduce the quantum phenomena called decoherence. In that context we explore one of the most exotic of its consecuences, the CPT violation. We work in three avor generation case where making the SU(3) decomposition of the operators we encounter that there exist fteen parameters in the decoherence matrix that explicitly violate CPT. Regarding four of those parameteres we choose one case of decoherence which will be tested at DUNE.
10
artÃculo
Publicado 2013
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Original abstract: We calculated the distributed surface mass and energy balance of Shallap Glacier, Cordillera Blanca, Peru (9° S, 77° W, 4700–5700 m a.s.l., ~ 7 km2), on hourly time steps for two years (September 2006–August 2008) using a process-based model and meteorological measurements as input. Model parameter combinations were optimized against 21 temporal readings of 20 stakes in the ablation zone of the glacier. Uncertainty caused by model input parameters and parameterization schemes was estimated using a leave-one out cross-validation scheme, which yields values of root mean square deviation (RMSD) of surface height change < 1 m (< 10% of the measured amplitude) for all stakes. With the best parameter combination (smallest RMSD) applied, the modeled annual surface mass balance of the glacier was -0.32 ± 0.4 m w.e. (water equivalent) for September 2006–August 2007 and...
11
artÃculo
Publicado 2020
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Por naturaleza el cielo no es totalmente limpio, sin embargo cuando la concentración de partÃculas es mayor a la normal puede atenuar con mayor intensidad la de radiación solar. Por lo que la cantidad de radiación solar que llega hasta la superficie terrestre depende en gran medida de la turbidez atmosférica. De esta manera, el objetivo de este trabajo fue estimar los valores óptimos diarios de la turbidez atmosférica y parámetros radiativos de superficie tales como: el coeficiente de turbidez de Angstrom (β), exponente de longitud de onda de Angstrom (α), el albedo de dispersión simple (ω0) y dispersión ascendente (Fc). Mediante mediciones de radiación solar incidente (global, directa y difusa), realizadas entre junio y julio del 2019 en la Provincia de Huancayo-Perú, se realizó los cálculos de los parámetros antes presentados. El modelo numérico usado para calcular l...
12
tesis de maestrÃa
We consider a beyond standard physics scenario, where neutrino is considered as an open quantum system. In order to have that consideration we use the Lindblad master equation, which introduce the quantum phenomena called decoherence. In that context we explore one of the most exotic of its consecuences, the CPT violation. We work in three avor generation case where making the SU(3) decomposition of the operators we encounter that there exist fteen parameters in the decoherence matrix that explicitly violate CPT. Regarding four of those parameteres we choose one case of decoherence which will be tested at DUNE.
13
objeto de conferencia
Glaciers in Peruvian Andes play an important role for local hydrology. To quantify the availability of glacier meltwater in a climate change scenario, surface energy (SEB) and mass balance (MB) models are required. However, few studies of SEB and MB modeling using coupled process-based models were carried out for this region. In this study, we use the newly updated COupled Snowpack and Ice surface energy and mass balance model in PYthon (COSIPY) in its 2-dimesnional spatially distributed version to simulate energy and mass fluxes over Artesonraju Glacier, Peruvian Andes, from 2016 to 2018. A glacier mass balance program was started at this glacier in 1995, with installation of a network of 22 ablation stakes and two automatic weather stations were started operating since 2005. COSIPY is forced by weather parameters like solar radiation, air temperature, relativity humidity, air pressure,...
14
tesis de maestrÃa
Publicado 2023
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A través de esta investigación se pretende sentar las bases del uso de modelos predictivos con inteligencia artificial basados en machine learning aplicado al diagnóstico técnico del Ãndice de salud en los interruptores de potencia de una empresa de transmisión de energla eléctrica, con el fin de obtener un modelo predictivo con inteligencia artificial que sea efectivo y eficiente, el cual será entrenado con todo el conocimiento experto que se tiene de estudios anteriores para obtener un modelo predictivo óptimo basado en machine leaming, que a diferencia del método tradicional usado en la empresa (lógica fuzzy) donde se le debe indicar a la máquina cuáles son las reglas de parametrización y tener un criterio de inferencia lógica para cada regla, el modelo predictivo utilizó todos los parámetros técnicos (variables predictoras) que intervinieron en el diagnóstico del Ã...
15
artÃculo
Publicado 2022
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In this work a sufficient condition is shown to obtain transitivity in families of piecewise increassing maps with an inevitable discontinuity in x=0. Specifically, it is shown that the characteristics of a large class of transformations of the real line with a discontinuity in x=0 to be transitive (exhibits a dense orbit), they are the following: f has no fixed points, f has a vertical asymptote at x=0 and the preimage of zero is different from empty. In particular, the famous Boole transformation together with some of its parameterizations they exhibit these characteristics. As a particular case, for the family to a parameter of hyperbolas its dynamic behavior is explicitly determined according to the values of the parameter p > 0.
16
artÃculo
Publicado 2015
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Satellites are an alternative source of rainfall data used as input to hydrological models in poorly gauged or ungauged regions. They are also useful in regions with highly heterogeneous precipitation, such as the tropical Andes. This paper evaluates three satellite precipitation datasets (TMPA, CMORPH, PERSIANN), as well as a dataset based only on rain gauge data (HYBAM), and their impacts on the water balance of the Western Amazon basin, a region where hydrological modeling and hydrological forecasting are poorly developed. These datasets were used as inputs in the MGB-IPH hydrological model to simulate streamflows for the 2003-2009 period. The impacts of precipitation on model parameterization and outputs were evaluated in two calibration experiments. In Experiment 1, parameter sets were separately defined for each catchment; in Experiment 2, a single parameter set was defined for the...
