New development: Directly elected mayors in Italy: creating a strong leader doesn’t mean creating strong leadership

More than 20 years after their introduction, directly elected mayors are key players in Italian urban governance. This article explains the main effects of this reform on local government systems and provides lessons for other countries considering directly elected mayors

Linear-Accelerator Program

Contains reports on one research project

Fast ML estimation of dynamic bifactor models : an application to European inflation

Generalizamos el algoritmo EM espectral para modelos factoriales dinámicos de Fiorentini, Galesi y Sentana (2014) a modelos bifactoriales con factores tanto globales como regionales. Aprovechamos la raleza de las matrices de coefi cientes de manera que se puedan estimar dichos modelos por máxima verosimilitud con numerosas series de múltiples regiones. También obtenemos expresiones sencillas para los gradientes espectrales y la matriz de información, lo que nos permite utilizar el algoritmo del gradiente cerca del óptimo. Exploramos la capacidad de un modelo con un factor global y tres regionales para capturar la dinámica de la infl ación en 25 países europeos durante 1999-2014We generalise the spectral EM algorithm for dynamic factor models in Fiorentini, Galesi and Sentana (2014) to bifactor models with pervasive global factors complemented by regional ones. We exploit the sparsity of the loading matrices so that researchers can estimate those models by maximum likelihood with numerous series from multiple regions. We also derive convenient expressions for the spectral scores and information matrix, which allows us to switch to the scoring algorithm near the optimum. We explore the ability of a model with one global factor and three regional factors to capture infl ation dynamics across 25 European countries in the period 1999-201

Modern Electronic Techniques Applied to Physics and Engineering

Contains reports on two research projects

Pump and probe damage testing for investigation of transient material modifications associated with laser damage in optical materials

Laser-induced breakdown in the bulk of transparent dielectric materials is associated with the generation of extreme localized conditions of temperatures and pressures. In this work, we perform pump and probe damage testing experiments to investigate the evolution of transient absorption by the host material arising from modifications following confined laser energy deposition in fused silica and DKDP materials. Specifically, we measure the size of the damage sites observed in the region of spatial overlap between the pump and probe pulses versus probe time delay and energy. Results of this proof-of-principle experimental work confirm that material modifications under extreme conditions created during a damage event include transient optical absorption. In addition, we found that the relaxation times of the induced absorption are very distinct for DKDP and SiO{sub 2} even under identical excitation conditions, on the order of 100 ns and 100 {micro}s, respectively

Exposing the Contradictory Claims, Myths and Illusions of the “Secrets of Business Success and Company Longevity†Genre

Over the last three decades, several management consultants, academics and business practitioners have laid claim to identifying “the secrets†of business success and company longevity. However, a systematic analysis of 24 studies in this genre revealed fundamental disagreements over the elements these authors claim are the primary drivers of business performance and longevity, and demonstrates that they share eight methodological and analytical flaws. Furthermore, many of the claims they made about “the secrets†of business success have not stood the test of time. The paper explains why business practitioners will find little in these studies to help their companies become more successful now and in the future, and also speculates why several of these studies became international best-sellers during the 1980s, 1990s and 2000s. It concludes by suggesting some new avenues for future research in this domain, and highlights the practical implications of these findings for business practitioners

Modern Electronic Techniques Applied to Physics and Engineering

Contains reports on three research projects

Parameter Estimation Method that Directly Compares Gravitational Wave Observations to Numerical Relativity

We present and assess a Bayesian method to interpret gravitational wave signals from binary black holes. Our method directly compares gravitational wave data to numerical relativity simulations. This procedure bypasses approximations used in semi-analytical models for compact binary coalescence. In this work, we use only the full posterior parameter distribution for generic nonprecessing binaries, drawing inferences away from the set of NR simulations used, via interpolation of a single scalar quantity (the marginalized log-likelihood, $\ln {\cal L}$) evaluated by comparing data to nonprecessing binary black hole simulations. We also compare the data to generic simulations, and discuss the effectiveness of this procedure for generic sources. We specifically assess the impact of higher order modes, repeating our interpretation with both $l\le2$ as well as $l\le3$ harmonic modes. Using the $l\le3$ higher modes, we gain more information from the signal and can better constrain the parameters of the gravitational wave signal. We assess and quantify several sources of systematic error that our procedure could introduce, including simulation resolution and duration; most are negligible. We show through examples that our method can recover the parameters for equal mass, zero spin; GW150914-like; and unequal mass, precessing spin sources. Our study of this new parameter estimation method demonstrates we can quantify and understand the systematic and statistical error. This method allows us to use higher order modes from numerical relativity simulations to better constrain the black hole binary parameters