Interbank Rate and the Liquidity of the Market.

In this paper we study the dynamics of the interbank rate in Chile, with special attention to the role of liquidity provided by private depositors and by the central bank’s open market operations on a daily basis. The main aim of this paper is the use of disaggregated and high frequency data on such variables. The most relevant findings are related to the statistical and economic significance of speed of convergence, calendar effects and repos operations. The Central Bank plays a more important role injecting than draining liquidity through discretionary operations. However, there are not asymmetries in terms of the effectiveness of the discretionary injections and drainages operations depending on the liquidity market status. In terms of effect by class of bank, large- and medium-size banks are less receptive to monetary operations; by contrast small-size banks are the most responsive, which is consistent with its traditional position as a liquidity demander. Finally, private deposits do not play an important role on the dynamics of the interbank rate during the sample period.

Effect of extinction on the high-energy optical response of photonic crystals

An analysis of the optical response of photonic crystals in the high-order band energy range is herein presented. High and abruptly fluctuating specular reflectance is predicted for perfect lattices at those energies even in the absence of any photonic gap or pseudogap. As optical extinction is gradually introduced, it is possible to reproduce experimental results found in the literature and which have recently been the subject of an intense debate. Band structure calculations demonstrate that extinction is extraordinarily amplified in the high-energy range and is responsible for the features so far observed in that range in real crystalsConsejo Superior de Investigaciones Científicas 2005AR0070Universidad de Buenos Aires ANPCYT-BID 802Agencia Nacional de Promoción Científica y Tecnológica OC-AR03-14099Ministerio de Educación y Ciencia MAT2005-0302

Micro-Jet Test Facility for Aerospace Propulsion Engineering Education

This paper describes the methodology that has been developed and implemented at the School ofAeronautics (ETSIA) of the Universidad Politecnica de Madrid (UPM) to familiarize aerospaceengineering students with the operation of real complex jet engine systems. This methodology has atwo-pronged approach: students carry out preparatory work by using, first, a gas turbineperformance prediction numerical code; then they validate their assumptions and results on anexperimental test rig. When looking at the educational aspects, we have taken care that, apart frombeing sufficiently robust and flexible, the experimental set-up is similar to real jet engine rigs, so thestudents are not constrained to exploring a much too limited parametric space. Also, because afacility like this is usually subject to extensive and somewhat rugged use, we have focused on a lowcost design

Imperios en fragmentación: Occidente Romano y América Hispana. Estructuras convergentes y tiempos diferentes

El artículo analiza las semejanzas y divergencias entre ambos procesos históricos. El principal elemento común es la importancia de las ciudades y de sus élites urbanas en la Europa bajo imperial y en la América hispana virreinal. La principal diferencia radica en la duración del proceso de fragmentación: más de un siglo en la primera y apenas dos decenios en la segunda.The paper analyzes the similarities and the differences between the two historical processes. The main comun factor is the decisive rôle of the cities and their urban elites in the Later Roman Empire and in the Virreinal America. The main differency is the time lastings of both movements of political fragmentation: more than a century in the first one and near two decennies in the second one

A general trimming approach to robust Cluster Analysis

We introduce a new method for performing clustering with the aim of fitting clusters with different scatters and weights. It is designed by allowing to handle a proportion $\alpha$ of contaminating data to guarantee the robustness of the method. As a characteristic feature, restrictions on the ratio between the maximum and the minimum eigenvalues of the groups scatter matrices are introduced. This makes the problem to be well defined and guarantees the consistency of the sample solutions to the population ones. The method covers a wide range of clustering approaches depending on the strength of the chosen restrictions. Our proposal includes an algorithm for approximately solving the sample problem.Comment: Published in at http://dx.doi.org/10.1214/07-AOS515 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org