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Archivo para junio, 2017

Algunos valores para juegos TU como funciones de particiones


SEMINARIO DEL DOCTORADO DE ESTADÍSTICA, OPTIMIZACIÓN Y MATEMÁTICA APLICADA. CURSO 2016-2017

Título: Algunos valores para juegos TU como funciones de particiones

Ponentes: Gloria Fiestras-Janeiro (Universidad de Vigo)

Fecha: Martes 18 de julio de 2017 a las 12:30 horas

Lugar: Sala de seminarios, Edificio Torretamarit, Universidad Miguel Hernández (Campus de Elche)

Resumen:

Los juegos TU como funciones de particiones son estructuras apropiadas para modelizar las ganancias/costes de una coalición teniendo en cuenta como se organizan el resto de los jugadores. En esta charla revisaremos algunos valores propuestos en la literatura, centrándonos en sus propiedades. En particular, revisaremos el valor de Myerson (Myerson 1977), el valor de Bolger (Bolger 1989), el valor libre de externalidades (de Clippel y Serrano 2008; Do and Norde 2007) y el valor de McQuillin (2009)


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Miércoles, 28 de junio de 2017 Sin comentarios

Measuring Productivity Change Accounting for Adjustment Costs: Evidence from the Food Industry in the European Union


SEMINARIO DEL DOCTORADO DE ESTADÍSTICA, OPTIMIZACIÓN Y MATEMÁTICA APLICADA. CURSO 2016-2017

Título: Measuring Productivity Change Accounting for Adjustment Costs: Evidence from the Food Industry in the European Union

Ponentes: Magdalena Kapelko (Wroclaw University of Economics, Institute of Applied Mathematics, Department of Logistics)

Fecha: Martes 11 de julio de 2017 a las 10:00 horas

Lugar: Sala de seminarios, Edificio Torretamarit, Universidad Miguel Hernández (Campus de Elche)

Resumen:

This paper extends the measurement of dynamic productivity change over time to provide its full decomposition into economically meaningful components in the Data Envelopment Analysis framework. The dynamic approach accounts for dynamics of production decisions via adjustment costs and is visualized as a dynamic Luenberger productivity change indicator. The paper also estimates the dynamic productivity change and its components for a large dataset of European food companies from 2004 till 2012, grouped into Eastern, Southern, and Western regions. The study reveals three main results. First, the overall trend of dynamic technical regress and positive dynamic technical inefficiency change across almost all regions and sectors was found. Second, some differences for this general pattern were found for the bakery industry and for Eastern European firms. Thirdly, there are also some remarkable changes in indicators observed during the periods related to the financial crisis and the volatility of agricultural commodity prices.


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Miércoles, 28 de junio de 2017 Sin comentarios

Aplicaciones de modelos jerárquicos bayesianos en Epidemiología en Plantas


SEMINARIO DEL DOCTORADO DE ESTADÍSTICA, OPTIMIZACIÓN Y MATEMÁTICA APLICADA. CURSO 2016-2017

Título: Aplicaciones de modelos jerárquicos bayesianos en Epidemiología en Plantas

Ponentes: Joaquín Martínez Minaya (Universitat de València)

Fecha: Viernes 16 de junio de 2017 a las 11:30 horas

Lugar: Sala de seminarios, Edificio Torretamarit, Universidad Miguel Hernández (Campus de Elche)

Resumen:

En los últimos años, el uso de modelos estadísticos complejos en disciplinas como la Epidemiología en plantas ha aumentado con el objetivo de ayudarnos a entender el comportamiento de las enfermedades en este ámbito. La dificultad que presentan algunos de estos modelos hace difícil tanto el proceso de estimación como el de predicción. Los modelos jerárquicos bayesianos parecen una buena alternativa para abordar este tipo de problemas y están basados principalmente en la premisa de que ambos, información e incertidumbre se pueden expresar en términos de distribuciones de probabilidad. En esta charla, presentamos modelizaciones para el estudio de algunas enfermedades en plantas, como son la mancha negra de los cítricos o la mancha foliar del caqui.


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Miércoles, 14 de junio de 2017 Sin comentarios

Small-scale fisheries in Brazil: a not-so-invisible problem


SEMINARIO DEL DOCTORADO DE ESTADÍSTICA, OPTIMIZACIÓN Y MATEMÁTICA APLICADA. CURSO 2016-2017

Título: Small-scale fisheries in Brazil: a not-so-invisible problem

Ponentes: Priscila Lopes (Universidade Federal do Rio Grande do Norte, Brazil)

Fecha: Viernes 16 de junio de 2017 a las 12:00 horas

Lugar: Sala de seminarios, Edificio Torretamarit, Universidad Miguel Hernández (Campus de Elche)

Resumen:

Brazil is proportionally a relatively unimportant player in the world fisheries scenario. However, small-scale fisheries (SSF) specifically are crucial for local livelihoods and the food security of millions of people, both on the coast and inland. Such fisheries provide more than 50% of the total Brazilian catches, suggesting that they can be highly impacting on the local ecosystems, especially on vulnerable ones, such as coastal reefs. Despite having some preferential target species, SSF is highly diverse and adaptive, depending on the environment, but also on the socioeconomic context. For being mostly coastal and exploiting shallow waters, many of the stocks targeted cannot undergo intensive fishing pressure, which have put many key species in a vulnerable situation, with some of them being locally extinct already. Topping up the problem, Brazil does not have a fishery statistical program since 2011, and has been cutting research funding continuously since 2014. To partially overcome the limitations, we have been developing alternative, affordable and reliable tools to collect and reconstruct fishing data, usually with the support of fishers. As there is official interest in managing such fisheries either, we have to stimulate and count on participatory initiatives to implement management as well and to understand, counterbalance or adjust, when necessary, the general impacts of development projects and of protected areas.


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Jueves, 8 de junio de 2017 Sin comentarios

A convex approach to differential inclusions with prox-regular sets


SEMINARIO DEL DOCTORADO DE ESTADÍSTICA, OPTIMIZACIÓN Y MATEMÁTICA APLICADA. CURSO 2016-2017

Título: A convex approach to differential inclusions with prox-regular sets

Ponentes: Dr. Abderrahim Hantoute (Center for Mathematical Modeling, University of Chile)

Fecha: Martes 13 de junio de 2017 a las 18:30 horas

Lugar: Sala de seminarios, Edificio Torretamarit, Universidad Miguel Hernández (Campus de Elche)

Resumen:

We study the existence and stability of the solutions for differential inclusions governed by the normal cone to a prox-regular set and subject to a Lipschitz perturbation. We prove that such apparently more general systems can be indeed remodeled into the classical theory of differential inclusions involving maximal monotone operators. This result permits us to make use of the rich and abundant achievements in this class of monotone operators to derive the desired existence result and stability analysis, as well as the continuity and differentiability properties of the solutions. This going back and forth between these two kinds of differential inclusions is made possible thanks to a viability result for maximal monotone operators. This is a joint work with S. Adly and Bao Tran Nguyen.

 


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Jueves, 8 de junio de 2017 Sin comentarios

Differences in teachers’ efficiency: evidence for Spain


SEMINARIO DEL DOCTORADO DE ESTADÍSTICA, OPTIMIZACIÓN Y MATEMÁTICA APLICADA. CURSO 2016-2017

Título: Differences in teachers’ efficiency: evidence for Spain

Ponentes: Gabriela Sicilia (Universidad Autónoma de Madrid)

Fecha: Miércoles 7 de junio de 2017 a las 12:00 horas

Lugar: Sala de seminarios, Edificio Torretamarit, Universidad Miguel Hernández (Campus de Elche)

Resumen:

This research contributes to the ongoing debate about differences in teachers’ performance. We introduce a new methodology that combine production frontier and impact evaluation insights that allows using DEA as an identification strategy of a treatment with high and low quality teachers within schools to assess their performance. We use a unique database in Spain that supplies information on two classrooms at 4th grade in primary education, where students and teachers were randomly assigned into the two classrooms at each school. We find considerable differences in teachers’ efficiency across schools and also significant effects on students’ achievement. In line with previous findings, we find that neither teacher experience nor academic training explains teachers’ efficiency. Conversely, being a female teacher, having worked five or more years in the same school, repeating a second year with the same group or having smaller class sizes positively affects the efficiency of teachers.


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Lunes, 5 de junio de 2017 Sin comentarios

A Wald-type test statistic based on robust modified median estimator in logistic regression models


SEMINARIO DEL DOCTORADO DE ESTADÍSTICA, OPTIMIZACIÓN Y MATEMÁTICA APLICADA. CURSO 2016-2017

Título: A Wald-type test statistic based on robust modified median estimator in logistic regression models

Ponentes: Tomáš Hobza (Czech Technical University in Prague)

Fecha: Lunes 5 de junio de 2017 a las 12:00 horas

Lugar: Sala de seminarios, Edificio Torretamarit, Universidad Miguel Hernández (Campus de Elche)

Resumen:

This contribution deals with robust estimation and hypothesis testing in logistic regression models. It introduces a modified median estimator of the underlying parameters of these models based on statistically smoothed binary responses and gives its asymptotic distribution.

Using the modified median estimator, a Wald-type test statistic for testing linear hypotheses in the logistic regression model is also considered and its asymptotic distribution is obtained.

Sensitivity to contaminations and leverage points is studied by simulations and compared in this manner with the sensitivity of some robust estimators and tests previously introduced to the logistic regression. The new estimator and test based on it appears to be more robust for larger sample sizes and higher levels of contamination.

Key words: Logistic regression, Median estimator, Robustness, Wald-type tets.


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Lunes, 5 de junio de 2017 Sin comentarios

ANUNCIO: INTRODUCCIÓN AL DESARROLLO DE PAQUETES EN R


CURSO

Título: Introducción al desarrollo de paquetes en R

Ponentes:

Virgilio Gómez-Rubio (Universidad Castilla-La Mancha)

Fecha: 11-12 julio 2017

Lugar: Facultad de CC de la Empresa. Universidad Politécnica de Cartagena

Información:

Cartel Taller R


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Lunes, 5 de junio de 2017 Sin comentarios