Elementos semiinfinitos de flexión

Existen situaciones para las que los resultados de interés corresponden a una zona pequeña de la estructura en comparación con su totalidad. La utilización de elementos infinitos constituye la posibilidad que evita un esfuerzo excesivo de cálculo. Esta idea se aplica en este artículo al análisis estático de la flexión de placas, desarrollando un elemento finito rectangular con un lado situado a distancia infinita. La función de decrecimiento de los movimientos en el interior del elemento es exponencial con un parámetro cuyo valor se determina mediante minimización de la energía potencial total. Se presentan resultados obtenidos con el elemento, contrastando su bondad y eficacia en comparación con un cálculo convencional. Se comentan finalmente distintas extensiones posibles del elemento

Capital market development : whither Latin America ?

Over the past decades, many countries have implemented significant reforms to foster capital market development. Latin American countries were at the forefront of this process. The authors analyze where Latin American capital markets stand after these reforms. They find that despite the intense reform effort, capital markets in Latin America remain underdeveloped relative to markets in other regions. Furthermore, stock markets are below what can be expected, given Latin America's economic and institutional fundamentals. The authors discuss alternative ways of interpreting this evidence. They argue that it is difficult to pinpoint which policies Latin American countries should pursue to overcome their poor capital market development. Moreover, they argue that expectations about the outcome of the reform process may need to be revisited to take into account intrinsic characteristics of emerging economies. The latter may limit the scope for developing deep domestic capital markets in a context of international financial integration.Markets and Market Access,Economic Theory&Research,Access to Markets,Financial Economics,Financial Intermediation

Innovative experiences in access to finance : market friendly roles for the visible hand ?

Interest in access to finance has increased significantly in recent years, as growing evidence suggests that lack of access to credit prevents lower-income households and small firms from financing high return investment projects, having an adverse effect on growth and poverty alleviation. This study describes some recent innovative experiences to broaden access to credit. These experiences are consistent with an emerging new view that recognizes a limited role for the public sector in financial markets, but contends that there might be room for well-designed, restricted interventions in collaboration with the private sector to foster financial development and broaden access. The authors illustrate this view with several recent experiences inLatin America and then discuss some open policy questions about the role of the public and private sectors in driving these financial innovations.Debt Markets,Banks&Banking Reform,,Emerging Markets,Bankruptcy and Resolution of Financial Distress

Stock market development under globalization : whither the gains from reforms ?

Over the past decades, many countries have implemented significant reforms to foster domestic capital market development. These reforms included stock market liberalization, privatization programs, and the establishment of regulatory and supervisory frameworks. Despite the intense reform efforts, the performance of capital markets in several countries has been disappointing. To study whether reforms have had the intended effects on capital markets, the authors analyze the impact of six capital market reforms on domestic stock market development and internationalization using event studies. They find that reforms tend to be followed by significant increases in domestic market capitalization, trading, and capital raising. Reforms are also followed by an increase in the share of activity in international equity markets, with potential negative spillover effects on domestic markets.Markets and Market Access,Economic Theory&Research,Access to Markets,Privatization,Corporate Law

De Martín I a Fernando I: Itinerario de un compromiso (1410-1412)

La muerte de Martín el Humano en mayo de 1410 significó el agravamiento de la crisis dinástica que padecía la Corona de Aragón desde que prácticamente un año antes, el 25 de julio de 1409, hubiese fallecido su hijo, Martín el Joven, dejando el trono sin heredero. Se iniciaba de este modo un turbulento interregno, de más de dos años de duración, que podemos dividir en tres grandes etapas. La primera de ellas incluye los meses transcurridos entre la muerte de Martín I, el 31 de mayo de 1410, y el asesinato del arzobispo de Za ragoza, el 1 de junio de 1411; la segunda etapa transcurre entre la convocatoria del Parlamento aragonés en Alcañiz y el traslado del catalán a Tortosa, entre los meses de julio y septiembre de 1411, y la aprobación de la Concordia de Alcañiz, el 15 de febrero de 1412; y la tercera abarca el desarrollo de la reunión de Caspe, desde su inicio, el día 29 de marzo, hasta la proclamación de Fernando I como rey, el 28 de junio de 1412

Unit Commitment with Load Uncertainty by Joint Chance-Constrained Programming

This paper presents an algorithm to solve a unit commitment problem that takes into account the uncertainty in the demand. This uncertainty is included in the optimization problem as a joint chance constraint that bounds the minimum value of the probability to jointly meet the deterministic power balance constraints. The demand is modeled as a multivariate, normally distributed, random variable and the correlation among different time periods is also considered. A deterministic mixed-integer linear programming problem is sequentially solved until it converges to the solution of the chanceconstrained optimization problem. Different approaches are presented to update the z-value used to transform the joint chance constraint into a set of deterministic constraints. Results from a realistic size case study are presented and the values obtained for the multivariate normal distribution probability are compared with the ones obtained by using a Monte Carlo simulation procedureUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

On the MIMO Capacity for Distributed System under Composite Rayleigh/Rician Fading and Shadowing

Wireless channels are commonly affected by short-term fading and long-term fading (shadowing). The shadowing effects must be taken into account also when mobility is present in the wireless scenario. Using a composite fading model, the total channel capacity can be studied for a scenario with short-term Rayleigh fading along with shadowing. This work provides quantitative results for these kinds of scenarios with Rayleigh fading and shadowing, considering also multiple-input and multiple-output systems, which have not been previously reported. In addition, the channel capacity has been studied in depth in its relation with the shadowing level, signal to noise ratio, and the number of elements in the multiple-input and multiple-output system. Moreover, the channel performance with shadowing has been compared to the one without it. Furthermore, Rician model with shadowing is studied and its results are reported. In addition, correlated and experimental results are provided. It is identified that the distributed MIMO systems can benefit from shadowing in Rician channels. This advantage has not been reported previously. This type of fading is proposed for massive MIMO by others and our results open the door to emulate massive MIMO on a reverberation chamber.This work has been supported by “Gobierno de Extremadura” with project number IB13113, PYR-2014 GENIL project (PYR-2014-CEB09-0010/MICINN), and CEIbioTIC project (mP_TIC_11)