Majoritarian Contests with Asymmetric Battlefields: An Experiment

We investigate a version of the classic Colonel Blotto game in which individual battles may have different values. Two players allocate a fixed budget across battlefields and each battlefield is won by the player who allocates the most to that battlefield. The winner of the game is the player who wins the battlefields with highest total value. We focus on the case where there is one large and several small battlefields, such that a player wins if he wins the large and any one small battlefield, or all the small battlefields. We compute the mixed strategy equilibrium for these games and compare this with choices from a laboratory experiment. The equilibrium predicts that the large battlefield receives more than a proportional share of the resources of the players, and that most of the time resources should be spread over more battlefields than are needed to win the game. We find support for the main qualitative features of the equilibrium. In particular, strategies that spread resources widely are played frequently, and the large battlefield receives more than a proportional share in the treatment where the asymmetry between battlefields is stronger.

Propagación y Extinción de Incendios Forestales y Urbanos para Entornos de Entrenamiento Virtuales

La formación de los bomberos es un proceso que incluye contenidos prácticos sobre cómo actuar ante incendios forestales y urbanos. La utilización de simuladores físicos tiene limitaciones impuestas por las condiciones de seguridad requeridas. Realizar prácticas controladas en condiciones reales está también altamente limitado por razones de factibilidad y de seguridad. Por tanto, la utilización de sistemas de entrenamiento de Realidad Virtual tiene especial relevancia.Las aportaciones de esta tesis están centradas en tres aspectos. El primero es el desarrollo de un entorno virtual para la simulación del entrenamiento e bomberos. Los escenarios considerados incluyen entornos forestales urbanos y mixtos. El entorno virtual puede ser accedido por bomberos que asumen distintos roles.El segundo es la generación de los algoritmos necesarios de la propagación y extinción de incendios dentro de los parámetros de interactividad del simulador. Para cumplir estos requisitos, se ha reducido la complejidad algorítmica a los elementos más fundamentales, entre ellos, la pendiente del terreno y la velocidad y dirección del viento. Además, se han añadido diversos efectos que aportan realismo a la propagación del fuego y su extinción: Spotting Fires, evaporación, modelo WaterJet.La definición de los escenarios incluye la clasificación del terreno o uso del suelo, los edificios y las barreras. La reconstrucción de escenarios reales a partir de información existente plantea problemas de heterogeneidad entre las distintas fuentes. La tercera aportación de esta tesis presenta las tecnologías semánticas como herramientas para solucionar los problemas de heterogeneidad de los datos y los distintos roles de los usuarios del sistema.

Simulación de incendios forestales y urbanos

La única forma que tienen los profesionales de aprender los procedimientos de extinción de incendios y gestión de los recursos es a través de maquetas o simulacros controlados. Este proyecto hace énfasis en la verificación de un conjunto de algoritmos de simulación y propagación de incendios facilitando la validación de los mismos por expertos. Los algoritmos validados se integrarán en un simulador interactivo dirigido al entrenamiento e instrucción del uso de los recursos para la extinción de incendios.

Biotic vs. Abiotic Control of Decomposition: A Comparison of the Effects of Simulated Extinctions and Changes in Temperature

The loss of species is known to have significant effects on ecosystem functioning, but only recently has it been recognized that species loss might rival the effects of other forms of environmental change on ecosystem processes. There is a need for experimental studies that explicitly manipulate species richness and environmental factors concurrently to determine their relative impacts on key ecosystem processes such as plant litter decomposition. It is crucial to understand what factors affect the rate of plant litter decomposition and the relative magnitude of such effects because the rate at which plant litter is lost and transformed to other forms of organic and inorganic carbon determines the capacity for carbon storage in ecosystems and the rate at which greenhouse gasses such as carbon dioxide are outgassed. Here we compared how an increase in water temperature of 5 degrees C and loss of detritivorous invertebrate and plant litter species affect decomposition rates in a laboratory experiment simulating stream conditions. Like some prior studies, we found that species identity, rather than species richness per se, is a key driver of decomposition, but additionally we showed that the loss of particular species can equal or exceed temperature change in its impact on decomposition. Our results indicate that the loss of particular species can be as important a driver of decomposition as substantial temperature change, but also that predicting the relative consequences of species loss and other forms of environmental change on decomposition requires knowledge of assemblages and their constituent species' ecology and ecophysiology.

Biotic vs. Abiotic Control of Decomposition: A Comparison of the Effects of Simulated Extinctions and Changes in Temperature

The loss of species is known to have significant effects on ecosystem functioning, but only recently has it been recognized that species loss might rival the effects of other forms of environmental change on ecosystem processes. There is a need for experimental studies that explicitly manipulate species richness and environmental factors concurrently to determine their relative impacts on key ecosystem processes such as plant litter decomposition. It is crucial to understand what factors affect the rate of plant litter decomposition and the relative magnitude of such effects because the rate at which plant litter is lost and transformed to other forms of organic and inorganic carbon determines the capacity for carbon storage in ecosystems and the rate at which greenhouse gasses such as carbon dioxide are outgassed. Here we compared how an increase in water temperature of 5 degrees C and loss of detritivorous invertebrate and plant litter species affect decomposition rates in a laboratory experiment simulating stream conditions. Like some prior studies, we found that species identity, rather than species richness per se, is a key driver of decomposition, but additionally we showed that the loss of particular species can equal or exceed temperature change in its impact on decomposition. Our results indicate that the loss of particular species can be as important a driver of decomposition as substantial temperature change, but also that predicting the relative consequences of species loss and other forms of environmental change on decomposition requires knowledge of assemblages and their constituent species' ecology and ecophysiology