40,122 research outputs found
Adversarial Risk Analysis: The Somali Pirates case
Some of the current world’s biggest problems revolve around security issues. This has raised recent interest in resource allocation models to manage security threats, from terrorism to organized crime through money laundering. One of those approaches is adversarial risk analysis, which aims at dealing with decision making problems with intelligent opponents and uncertain outcomes. We show here how such framework may cope with a current important security issue in relation with piracy in the Somali coasts. Specifically, we describe how to support the owner of a ship in managing risks from piracy in that area. We illustrate how a sequential defend-attack-defend model can be used to formulate this decision problem and solve it for the ship owner. Emphasis will be put on explaining how we can model the Pirates thinking in order to anticipate their behavior and how it would lead to a predictive probability distribution, from the defender’s perspective, over what the Pirates may do
Adversarial Risk Análysis for Counterterrorism Modelling
Recent large scale terrorist attacks have raised interest in models for resource allocation against terrorist threats. The unifying theme in this area is the need to develop methods for the analysis of allocation decisions when risks stem from the intentional actions of intelligent adversaries. Most approaches to these problems have a game theoretic flavor although there are also several interesting decision analytic based proposals. One of them is the recently introduced framework for adversarial risk analysis, which deals with decision making problems that involve intelligent opponents and uncertain outcomes. We explore how adversarial risk analysis addresses some standard counterterrorism models: simultaneous defend-attack models, sequential defend-attack-defend models and sequential defend-attack models with private information. For each model, we first assess critically what would be a typical game theoretic approach and then provide the corresponding solution proposed by the adversarial risk analysis framework, emphasizing how to coherently assess a predictive probability model of the adversary’s actions, in a context in which we aim at supporting decisions of a defender versus an attacker. This illustrates the application of adversarial risk analysis to basic counterterrorism models that may be used as basic building blocks for more complex risk analysis of counterterrorism problems
Numerical study of the incompressible flow around a particle with roughness
Estudio mediante simulación en el programa CFD de una partícula con forma de cilindro circular por la que pasa un flujo incomprensible. Inicialmente, se realiza el estudio de la partícula con superficie perfectamente lisa para números de Reynolds de 80 y 240. Posteriormente se hace el estudio de esa misma partícula con diferentes rugosidades, variando en la superficie la frecuencia en unos casos y el radio en otros, de nuevo para los números de Reynolds de 80 y 240.
Al comparar los resultados obtenidos de la partícula lisa con las partículas con variación de radio o variación de frecuencia en su superficie, se observa como el coeficiente de arrastre, coeficiente principal a tener en cuenta, aumenta cada vez más conforme se le va añadiendo una rugosidad mayor a la partícula. Otros coeficientes como el de presión, el de elevación y la velocidad, también son estudiados.The mainobjectiveisthestudyofacircularcylinderwhenthecylinderhasawavywall.Forthis
reason, thein
uenceofachangeinfrequencyandradiusforthecylinderwallareinvestigated.
FlowswithReynoldsnumbersof80and240forthecircularcylinderwithasmoothwallhavebeen
calculated asabenchmark.Thevaluesobtainedarecomparedwithacircularcylinderwithwavywall,
namely,withthein
uenceofthechangesinfrequencyandradiusmentionedaboveforthecylinder
wall.Whereonecanseehowtheparametersstudiedmovefurtherandfurtherawayfromthevalues
of thecircularcylinderwithasmoothwallwhentheroughnessincreases.Departamento de Ingeniería Energética y FluidomecánicaMáster en Ingeniería Industria
Dominación sparse para conmutadores y estimaciones cuantitativas
Dada una funci ́on localmente integrable y un operador lineal T definimos el commutator [b, T ] como
[b, T ]f (x) = b(x)T f (x) − T (bf )(x).
En esta charla presentaremos resultados de dominación sparse para conmutadores y sus iteraciones para los casos en que T es un una integral singular rough, un operador A-Hörmander o un operador de Calderón-Zygmund. Suponiendo adicionalmente que b ∈ BMO o alguna clase análoga mostraremos la versatilidad de las técnicas de dominación sparse para obtener estimaciones cuantitativas.
Esta charla está basada en trabajos conjuntos con A. Lerner, S. Ombrosi, C. P ́erez, L. Roncal y G. Ibañez-Firnkorn.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
A quantitative approach to weighted Carleson Condition
Quantitative versions of weighted estimates obtained by F. Ruiz and J.L.
Torrea in the 80's for the operator are obtained. As a consequence, some sufficient conditions for the
boundedness of in the two weight setting in the spirit of the
results obtained by C. P\'erez and E. Rela and very recently by M.T. Lacey and
S. Spencer for the Hardy-Littlewood maximal operator are derived. As a
byproduct some new quantitative estimates for the Poisson integral are
obtained
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