Nonlinear elastic analysis of concrete beams based on the Smeared Crack Approach

In the present study, an analysis of plain and reinforced concrete beams under monotonic loading was made based on the Fixed Smeared Crack approach. The objectives of this research were to analyze the nonlinear behavior of the selected cases of analysis and to propose an alternative and simple model for the analysis of beams under service loadings, by means of Committee 435 of the American Concrete Institute. A brittle model for concrete and a linear-elastic behavior for steel reinforcement bars were considered. Results are presented through force-displacement curves and the sequence of cracking propagation. Also, a comparison of calculated instantaneous deflections of simply supported beams was made between the proposed model and other researches. It was verified that the proposed algorithm can predict adequately the cracking process and the deflections of beams subjected to service loadings, taking into account experimental results from other authors

An algorithmic approach for simulating realistic irregular lattices.

There is a wide variety of computational experiments, or statistical simulations, in which regional scientists require regular and irregular lattices with a predefined number of polygons. While most commercial and free GIS software offer the possibility of generating regular lattices of any size, the generation of instances of irregular lattices is not a straightforward task. The most common strategy in this case is to find a real map that matches as closely as possible the required number of polygons. This practice is usually conducted without considering whether the topological characteristics of the selected map are close to those for an “average” map sampled in different parts of the world. In this paper, we propose an algorithm, RI-Maps, that combines fractal theory, stochastic calculus and computational geometry for simulating realistic irregular lattices with a predefined number of polygons. The irregular lattices generated with RI-Maps have guaranteed consistency in their topological characteristics, which reduces the potential distortions in the computational or statistical results due to an inappropriate selection of the lattices

Análisis de la distribución espacial de la reducción en la demanda de agua potable como efecto de políticas de ahorro en su consumo en el Área Metropolitana del Valle de Aburrá.

El presente estudio presenta un análisis, espacialmente desagregado, de la disminución en el consumo residencial de agua en el Área Metropolitana del Valle de Aburrá (AMVA) durante el periodo 2005 – 2010 e identificar las características socioeconómicas asociadas a estos patrones. Además, se analiza la forma cómo las políticas y campañas para incentivar la disminución del consumo de agua potable han sido acogidas en el AMVA. Los resultados obtenidos muestran claras diferencias espaciales (y por estrato) en los niveles de consumo de agua, así como en los niveles de reducción de dicho consumo en el período analizado. También, por medio de modelos de econometría espacial, se encuentra que las características socioeconómicas juegan un papel relevante a la hora de explicar los niveles de consumo de agua y que estos consumos presentan autocorrelación espacial sustantiva que indica que los niveles de consumo de agua potable en un área determinada no solo dependen de las características socioeconómicas del área, sino también de los niveles de consumo de las áreas vecinas. Por último, se encuentra que los impactos derivados del desincentivo económico al consumo excesivo, tiene un efecto inmediato que no perdura en el tiemp