Rosca participation in Benin: a commitment issue

In the light of first-hand data from a Beninese urban household survey in Cotonou, we investigate several motives aiming to explain participation in Rotating Savings and Credit Associations. We provide anecdotal pieces of evidence, descriptive statistics, FIML regressions and matching estimates which tend to indicate that most individuals use their participation in a rosca as a device to commit themselves to save money and to deal with self-control problems.

Aplicaciones Single Program Multiple Data (SPMD) en ambientes distribuidos

Un reto al ejecutar las aplicaciones en un cluster es lograr mejorar las prestaciones utilizando los recursos de manera eficiente, y este reto es mayor al utilizar un ambiente distribuido. Teniendo en cuenta este reto, se proponen un conjunto de reglas para realizar el cómputo en cada uno de los nodos, basado en el análisis de cómputo y comunicaciones de las aplicaciones, se analiza un esquema de mapping de celdas y un método para planificar el orden de ejecución, tomando en consideración la ejecución por prioridad, donde las celdas de fronteras tienen una mayor prioridad con respecto a las celdas internas. En la experimentación se muestra el solapamiento del computo interno con las comunicaciones de las celdas fronteras, obteniendo resultados donde el Speedup aumenta y los niveles de eficiencia se mantienen por encima de un 85%, finalmente se obtiene ganancias de los tiempos de ejecución, concluyendo que si se puede diseñar un esquemas de solapamiento que permita que la ejecución de las aplicaciones SPMD en un cluster se hagan de forma eficiente.

Memòria justificativa del treball realitzat durant l’estada a la Universitat de Wisconsin-Madison

Projecte de recerca elaborat a partir d’una estada a la Universitat de Wisconsin-Madison, EUA, Departament de Curriculum and Instruction, des de mitjans d’agost a mitjans de novembre de 2006. S’ha treballat en relació a la preparació de la tesi “Els grups interactius: una pràctica de les comunitats d’aprenentatge per a la inclusió de l’alumnat amb discapacitat “. La universitat de Wisconsin-Madison i en concret el departament de Curriculum and instruction compta amb professorat de reconegut prestigi internacional en l’àmbit de l’educació. Entre els temes que es treballen al departament i que vaig poder conèixer, en destaco les implicacions de l’educació en l’existència de desigualtats socials, així com les implicacions del govern i de les polítiques educatives en la creació i manteniment d’aquestes desigualtats, les reformes i polítiques educatives i el paper de l’educació en el més ampli context de la societat i les seves estructures, l’anàlisi del llenguatge vinculat amb les desigualtats i l’educació, la necessitat de tenir en compte la multiculturalitat des d’una perspectiva crítica, i les possibilitats de transformació en educació facilitades per les oportunitats d’interacció.

Price level convergence, purchasing power parity and multiple structural breaks: an application to US cities

This article provides a fresh methodological and empirical approach for assessing price level convergence and its relation to purchasing power parity (PPP) using annual price data for seventeen US cities. We suggest a new procedure that can handle a wide range of PPP concepts in the presence of multiple structural breaks using all possible pairs of real exchange rates. To deal with cross-sectional dependence, we use both cross-sectional demeaned data and a parametric bootstrap approach. In general, we find more evidence for stationarity when the parity restriction is not imposed, while imposing parity restriction provides leads toward the rejection of the panel stationar- ity. Our results can be embedded on the view of the Balassa-Samuelson approach, but where the slope of the time trend is allowed to change in the long-run. The median half-life point estimate are found to be lower than the consensus view regardless of the parity restriction.

Simulations of parasitic and intrinsic capacitances related to Multiple-Gate-Field-Effect Transistor architectures

Report for the scientific sojourn carried out at the Université Catholique de Louvain, Belgium, from March until June 2007. In the first part, the impact of important geometrical parameters such as source and drain thickness, fin spacing, spacer width, etc. on the parasitic fringing capacitance component of multiple-gate field-effect transistors (MuGFET) is deeply analyzed using finite element simulations. Several architectures such as single gate, FinFETs (double gate), triple-gate represented by Pi-gate MOSFETs are simulated and compared in terms of channel and fringing capacitances for the same occupied die area. Simulations highlight the great impact of diminishing the spacing between fins for MuGFETs and the trade-off between the reduction of parasitic source and drain resistances and the increase of fringing capacitances when Selective Epitaxial Growth (SEG) technology is introduced. The impact of these technological solutions on the transistor cut-off frequencies is also discussed. The second part deals with the study of the effect of the volume inversion (VI) on the capacitances of undoped Double-Gate (DG) MOSFETs. For that purpose, we present simulation results for the capacitances of undoped DG MOSFETs using an explicit and analytical compact model. It monstrates that the transition from volume inversion regime to dual gate behaviour is well simulated. The model shows an accurate dependence on the silicon layer thickness,consistent withtwo dimensional numerical simulations, for both thin and thick silicon films. Whereas the current drive and transconductance are enhanced in volume inversion regime, our results show thatintrinsic capacitances present higher values as well, which may limit the high speed (delay time) behaviour of DG MOSFETs under volume inversion regime.

The Division problem with voluntary participation

The division problem consists of allocating a given amount of an homogeneous and perfectly divisible good among a group of agents with single-peaked preferences on the set of their potential shares. A rule proposes a vector of shares for each division problem. The literature has implicitly assumed that agents will find acceptable any share they are assigned to. In this paper we consider the division problem when agents' participation is voluntary. Each agent has an idiosyncratic interval of acceptable shares where his preferences are single-peaked. A rule has to propose to each agent either to not participate or an acceptable share because otherwise he would opt out and this would require to reassign some of the remaining agents' shares. We study a subclass of efficient and consistent rules and characterize extensions of the uniform rule that deal explicitly with agents' voluntary participation.

The Multiple-partners assignment game with heterogeneous sales and multi-unit demands: competitive equilibria

A multiple-partners assignment game with heterogeneous sales and multiunit demands consists of a set of sellers that own a given number of indivisible units of (potentially many different) goods and a set of buyers who value those units and want to buy at most an exogenously fixed number of units. We define a competitive equilibrium for this generalized assignment game and prove its existence by using only linear programming. In particular, we show how to compute equilibrium price vectors from the solutions of the dual linear program associated to the primal linear program defined to find optimal assignments. Using only linear programming tools, we also show (i) that the set of competitive equilibria (pairs of price vectors and assignments) has a Cartesian product structure: each equilibrium price vector is part of a competitive equilibrium with all optimal assignments, and vice versa; (ii) that the set of (restricted) equilibrium price vectors has a natural lattice structure; and (iii) how this structure is translated into the set of agents' utilities that are attainable at equilibrium.

The participation of women in peace processes: the other tables

This paper argues that women’s absence in peace processes cannot be explained by their alleged lack of experience in dialogue and negotiation, but by a serious lack of will to include them in such important initiatives of change. Women have wide ranging experience in dialogue processes including many war and post-war contexts, but there has been a deliberate lack of effort to integrate them in formal peace processes. After introducing the research framework, the paper addresses women’s involvement in peace, and analyzes the role played by women in peace processes, through the cases of Sri Lanka and Northern Ireland. The paper concludes that peace processes are as gendered as wars, and for that reason gender has to be a guiding line for including women in peace processes.

Planificació general a l'aula inclusiva. El cas del Solsonès

El present treball de recerca es centra en l’estudi de la programació general de l’aula en entorns inclusius. Concretament, s’ha dut a terme un estudi de cas a la comarca del Solsonès ja que les característiques demogràfiques i educatives d’aquesta comarca han facilitat la inclusió escolar de tot l’alumnat amb discapacitat a l’aula ordinària. Els principals objectius de la investigació són descriure les pràctiques de planificació general del professorat de la comarca del Solsonès que ha atès a alumnat amb necessitats educatives especials i conèixer els aspectes relacionats amb la programació didàctica que es poden millorar a partir de processos de formació permanent i assessorament. L’anàlisi de la informació recollida a través de qüestionaris realitzats al professorat del Solsonès i un grup de discussió als professionals dels serveis externs, ens ha permès conèixer les pràctiques de planificació del professorat del Solsonès i fins a quin punt són similars a bones pràctiques, com l’Ensenyament Multinivell o el Disseny Universal de l’Aprenentatge, desenvolupades en altres contextos; així com, quins són els principals problemes i dificultats amb què es troben els i les professionals a l’hora de dur a terme les programacions a l’aula.