Network robustness assessed within a dual connectivity perspective

Network robustness against attacks has been widely studied in fields as diverse as the Internet, power grids and human societies. Typically, in these studies, robustness is assessed only in terms of the connectivity of the nodes unaffected by the attack. Here we put forward the idea that the connectivity of the affected nodes can play a crucial role in properly evaluating the overall network robustness and its future recovery from the attack. Specifically, we propose a dual perspective approach wherein at any instant in the network evolution under attack, two distinct networks are defined: (i) the Active Network (AN) composed of the unaffected nodes and (ii) the Idle Network (IN) composed of the affected nodes. The proposed robustness metric considers both the efficiency of destroying the AN and the efficiency of building-up the IN. We show, via analysis of both prototype networks and real world data, that trade-offs between the efficiency of Active and Idle network dynamics give rise to surprising crossovers and re-ranking of different attack strategies, pointing to significant implications for decision making

Theory of frequency-filtered and time-resolved N-photon correlations

A theory of correlations between N photons of given frequencies and detected at given time delays is presented. These correlation functions are usually too cumbersome to be computed explicitly. We show that they are obtained exactly through intensity correlations between two-level sensors in the limit of their vanishing coupling to the system. This allows the computation of correlation functions hitherto unreachable. The uncertainties in time and frequency of the detection, which are necessary variables to describe the system, are intrinsic to the theory. We illustrate the formalism with the Jaynes--Cummings model, showing how correlations of various peaks at zero or finite time delays bring new insights into the dynamics of open quantum systems.Comment: 12 pages, 2 figure

Arquitectura y web 2.0: nuevas estrategias de comunicación en arquitectura

En este Proyecto Final de Máster se hace un estudio diagnóstico que analiza el estado actual de los principales estudios de arquitectura, empresas inmobiliarias y promotoras de viviendas mediante un análisis (cuantitativo y cualitativo) de las herramientas de la web 2.0 que incorporan en sus páginas web. Del mismo modo, la investigación pretende, a través de las conclusiones extraídas, aplicar en un desarrollo posterior de la investigación los resultados obtenidos a una web real y comprobar las consecuencias de una utilización directa de las herramientas empleadas para ver cómo estas transformaciones pueden modificar el concepto del estudio de arquitectura, su presencia online y la relación con los actuales clientes y con aquéllos que puedan serlo.Tejedor Calvo, A. (2012). Arquitectura y web 2.0: nuevas estrategias de comunicación en arquitectura. http://hdl.handle.net/10251/17811.Archivo delegad

Surgical Indications and Techniques to Treat the Pain in Chronic Pancreatitis

Chronic pancreatitis (CP) is a progressive inflammatory process, of the pancreatic gland and leads to damage and decrease in glandular tissue. Clinically, the pain is the most outstanding and incapacitating sign (95% of patients), as well as exocrine pancreatic insufficiency. The two main objectives in CP treatment are pain relief and complication management. Pain is the main surgical treatment indication. Patients with pancreatic duct dilation require surgical drainage, which provides an important pain relief (70–80%). Decompression (drainage), resection and neuroablation are the most commonly used surgical treatment options of CP. Derivative surgical procedures as Puestow-Gillesby or its modification, Partington-Rochelle, are the best options if the Wirsung duct is dilated, and Izbiki procedure if it is not. Resection is the choice when there is an important affectation of the head of pancreas with repercussion in bile duct or duodenum, as well as those patients with suspicion of carcinoma or in those ones who cannot be ruled a malignant tumour. The resection surgical procedures are Whipple, Traverso-Longmire, Frey (resective-derivative) and Beger (resective-derivative). To conclude, surgeon must know not only every surgical procedure indications but also be familiarised with all of them. The surgical procedure must be individualised to the patient and the disease stage

The negative binomial distribution as a renewal model for the recurrence of large earthquakes

The negative binomial distribution is presented as the waiting time distribution of a cyclic Markov model. This cycle simulates the seismic cycle in a fault. As an example, this model, which can describe recurrences with aperiodicities between 0 and 0.5, is used to fit the Parkfield, California earthquake series in the San Andreas Fault. The performance of the model in the forecasting is expressed in terms of error diagrams and compared with other recurrence models from literature