The two membranes problem for fully nonlinear operators

We study the two membranes problem for two different fully nonlinear operators. We give a viscosity formulation for the problem and prove existence of solutions. Then we prove a general regularity result and the optimal C1,1 regularity when the operators are the Pucci extremal operators. We also give an example that shows that no regularity for the free boundary is to be expected to hold in general.Fil: Caffarelli, Luis. University of Texas at Austin; Estados UnidosFil: Duque, Luis. University of Texas at Austin; Estados UnidosFil: Vivas, Hernán Agustín. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Matemática; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

COMPETITIVIDAD DE LA CADENA ARROCERA DEL ESTADO PORTUGUESA, VENEZUELA, EN LOS PROCESOS DE INTEGRACIÓN EN SUDAMÉRICA

The rice chain in the Portuguesa state is of great significance for Venezuela because half of the country's production comes from that state. Activities' integration that goes from production to consumption have some specificities which, in rice producing countries, the most important are those linked to the production and transformation of raw materials. On top, political and economic instability induce to take unwise macroeconomic decisions that affect the monetary system and balance of the country causing clear negative impacts on the rice chain. Several countries from the CAN (Colombia) and MERCOSUR (Argentina, Brazil and Uruguay) have been selected either as exporters or importers and consequently as potential competitors on the international markets or even in the national market. In this work, it has been undertaken a competitiveness analysis of the rice chain, in the Portuguese state comparing the previously mentioned countries based on representative variables of rice production: yield per hectare and its evolution, price paid to farmers, production cost and profit; transformation: yield for whole grains; consumption: consumption per capita; trade balance for rice: import and export; monetary policy: annual and cumulative inflation, and exchange rate; and, finally, policies applied in the sector. The objective is to evaluate the competitiveness of the rice chain and to suggest corrective measures for the future.Portuguesa state, rice chain, competitiveness, international integration, Venezuela., Agribusiness,

Applying A Methodology For Educating Students With Special Needs: A Case Study

The introduction of innovative educational technologies opens up new ways of interacting with students. We propose to exploit this potential to help in the education of children with special needs. We analyze the state of the art of tools supporting the teaching process, focusing on the omissions of existing research. We propose a new framework to help throughout the whole teaching process and describe its application to Proyecto Aprender (Learn Project), an educational resource targeting children with learning difficulties. Finally, we outline some conclusions and current/future research lines

Compressive resistance level effect on impact performance of fi-ber reinforced concrete

Impact resistance represents a key property of fiber reinforced concrete (FRC). To study this property, a test method was recently proposed; which consists in repeated drops of a projectile on simply supported prisms, and allows to evaluate FRC behavior both at cracking and after cracking. With the aim of verifying the sensitiveness of this method, this paper analyzes the influence of the compressive strength of the FRC matrix on each parameter of the impact test. Three FRC incorporating 30 kg/m3 of hooked-end steel fibers were prepared, varying the water/cement ratio (0.59, 0.50 and 0.43). It was found that although only small effects on the cracking energy were observed as the concrete compressive strength increases, the post-cracking energy increased in a greater proportion. However, the cracking growth rate, an impact pa-rameter strongly sensitive to the type and content of fibers, remained practically constant for different compressive strength levels.Fil: Vivas Montes, Juan Carlos. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Construcciones; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; ArgentinaFil: Zerbino, Raul Luis. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Laboratorio de Entrenamiento Multidisciplinario para la Investigación Tecnológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ingeniería. Departamento de Construcciones; Argentin

Ciencia e innovación tecnológica como oportunidad estratégica para la solución con calidad de los problemas

Ciencia e innovación tecnológica como oportunidad estratégica para la solución con calidad de los problema

La intimidad en crisis: repensando su finalidad

El presente artículo tiene como finalidad advertir acerca de la problemática que se plantea a la hora de proteger la intimidad. Actualmente asistimos a un momento de decadencia en la que la intimidad es sistemáticamente lesionada. Todo el mundo graba a todo el mundo. Esta situación plantea importantes problemas que requieren una revisión de sus límites y comprensiónThis paper aims to warn about the problems that arise when protecting privacy. We are currently witnessing a period of decline on which privacy is systematically damaged. Everyone records everyone. This situation poses important problems that require a revision of its limits and understanding

Design of Telephony Services In Lotos

The purpose of this thesis is to design and validate a telephony system using the formal description language LOTOS and a series of tools provided by the Lotosphere Integrated Tool Environment, LITE. The starting point is a requirements document containing a series of informal specifications of services common to modern telephony systems. Special emphasis has been laid on choosing a design that simplifies the integration of additional telephone services in the specification. Most design decisions were thus taken with the purpose of creating an environment that could help different designers to develop distinct functionalities without the need for each one to be acquainted with other existing features in the system. To this end, the design was structured in a fashion that might enhance the extensibility of the system, as well as prevention and detection of incompatibilities between different features. A methodology is thus proposed for dealing with what is commonly known as the feature interaction problem for telephony systems

Ciencia e innovación tecnológica como oportunidad estratégica para la solución con calidad de los problemas

Ciencia e innovación tecnológica como oportunidad estratégica para la solución con calidad de los problema