Artículos con la etiqueta ‘Applications (stat.AP)’

Global Inequality in Energy Consumption from 1980 to 2010

Por • 31 dic, 2013 • Category: Economía

We study the global probability distribution of energy consumption per capita around the world using data from the U.S. Energy Information Administration (EIA) for 1980-2010. We find that the Lorenz curves have moved up during this time period, and the Gini coefficient G has decreased from 0.66 in 1980 to 0.55 in 2010, indicating a decrease in inequality. The global probability distribution of energy consumption per capita in 2010 is close to the exponential distribution with G=0.5. We attribute this result to the globalization of the world economy, which mixes the world and brings it closer to the state of maximal entropy. We argue that global energy production is a limited resource that is partitioned among the world population. The most probable partition is the one that maximizes entropy, thus resulting in the exponential distribution function. A consequence of the latter is the law of 1/3: the top 1/3 of the world population consumes 2/3 of produced energy. We also find similar results for the global probability distribution of CO2 emissions per capita.

Space-time correlations in urban sprawl

Por • 23 jun, 2013 • Category: Economía

Understanding demographic and migrational patterns constitutes a great challenge. Millions of individual decisions, motivated by economic, political, demographic, rational, and/or emotional reasons underlie the high complexity of demographic dynamics. Significant advances in quantitatively understanding such complexity have been registered in recent years, as those involving the growth of cities [Bettencourt LMA, Lobo J, Helbing D, Kuehnert C, West GB (2007) Growth,. Innovation, Scaling, and the Pace of Life in Cities, Proc Natl Acad Sci USA 104 (17) 7301-7306] but many fundamental issues still defy comprehension. We present here compelling empirical evidence of a high level of regularity regarding time and spatial correlations in urban sprawl, unraveling patterns about the inertia in the growth of cities and their interaction with each other.

Statistics, Causality and Bell’s theorem

Por • 26 jul, 2012 • Category: Ambiente

Bell’s (1964) theorem is popularly supposed to establish the non-locality of quantum physics as a mathematical-physical theory. Building from this, observed violation of Bell’s inequality in experiments such as that of Aspect and coworkers (1982) is popularly supposed to provide empirical proof of non-locality in the real world. This paper reviews recent work on Bell’s theorem, linking it to issues in causality as understood by statisticians. The paper starts with a new proof of a strong (finite sample) version of Bell’s theorem which relies only on elementary arithmetic and (counting) probability.

A proof of Bell’s inequality in quantum mechanics using causal interactions

Por • 26 jul, 2012 • Category: Ciencia y tecnología

We give a simple proof of Bell’s inequality in quantum mechanics which, in conjunction with experiments, demonstrates that the local hidden variables assumption is false. The proof sheds light on relationships between the notion of causal interaction and interference between particles.