Hemeroteca del mes septiembre, 2015

¿Comunidad organizada?

Por • 26 sep, 2015 • Category: Nacionales

Alejandro Moreno 22 de Septiembre 2015. Hubo un tiempo en el que el gran proyecto de todo grupo comprometido con los pobres y el pueblo, especialmente de esos sectores llamados entonces marginales o marginados, consistía principalmente en concientizar a las comunidades para que una vez conscientes de su dignidad y derechos se organizaran y sobre […]

Some Notes on Finite Sets

Por • 23 sep, 2015 • Category: Filosofía

These notes aim to give a gentle account to one approach to the theory of finite sets without making use of the natural numbers. They were written to be used as the basis for a student seminar. There are no real prerequisites except for a certain familiarity with the kind of mathematics seen in the first couple of years of a university mathematics course. The definition of being finite employed in these notes is usually called Kuratowski-finiteness and it is essentially that employed by Whitehead and Russell in Principia Mathematica.

Universality of market superstatistics

Por • 23 sep, 2015 • Category: Ambiente

We use a continuous-time random walk (CTRW) to model market fluctuation data from times when traders experience excessive losses or excessive profits. We analytically derive “superstatistics” that accurately model empirical market activity data (supplied by Bogachev, Ludescher, Tsallis, and Bunde)that exhibit transition thresholds. We measure the interevent times between excessive losses and excessive profits, and use the mean interevent time as a control variable to derive a universal description of empirical data collapse. Our superstatistic value is a weighted sum of two components, (i) a powerlaw corrected by the lower incomplete gamma function, which asymptotically tends toward robustness but initially gives an exponential, and (ii) a powerlaw damped by the upper incomplete gamma function, which tends toward the power-law only during short interevent times.

Inequality measures in kinetic exchange models of wealth distributions

Por • 22 sep, 2015 • Category: sociologia

In this paper, we study the inequality indices for some models of wealth exchange. We calculated Gini index and newly introduced k-index and compare the results with reported empirical data available for different countries. We have found lower and upper bounds for the indices and discuss the efficiencies of the models. Some exact analytical calculations are given for a few cases. We also exactly compute the quantities for Gamma and double Gamma distributions.

Measuring economic complexity of countries and products: which metric to use?

Por • 22 sep, 2015 • Category: Internacionales

Evaluating the economies of countries and their relations with products in the global market is a central problem in economics, with far-reaching implications to our theoretical understanding of the international trade as well as to practical applications, such as policy making and financial investment planning. The recent Economic Complexity approach aims to quantify the competitiveness of countries and the quality of the exported products based on the empirical observation that the most competitive countries have diversified exports, whereas developing countries only export few low quality products — typically those exported by many other countries. Two different metrics, Fitness-Complexity and the Method of Reflections, have been proposed to measure country and product score in the Economic Complexity framework. We use international trade data and a recent ranking evaluation measure to quantitatively compare the ability of the two metrics to rank countries and products according to their importance in the network.

A network analysis of the global energy market: an insight on the entanglement between crude oil and the world economy

Por • 22 sep, 2015 • Category: Economía

One major hurdle in the road toward a low carbon economy is the present entanglement of developed economies with oil. This tight relationship is mirrored in the correlation between most of economic indicators with oil price. This paper addresses the role of oil compared to the other three main energy commodities -coal, gas and electricity, in shaping the international trading network (ITW or WTW, world trade web) in the light of network theory. It initially surveys briefly the literature on the correlation between oil prices with economic growth and compares the concepts of time correlation with the concept of spatial correlation brought about by network theory. It outlines the conceptual framework underpinning the network measures adopted in the analysis and results are presented.

To Love or to Loathe: How is the World Reacting to China’s Rise?

Por • 21 sep, 2015 • Category: sociologia

China has experienced a spectacular economic growth in recent decades. Its economy grew more than 48 times from 1980 to 2013. How are the other countries reacting to China’s rise? Do they see it as an economic opportunity or a security threat? In this paper, we answer this question by analyzing online news reports about China published in Australia, France, Germany, Japan, Russia, South Korea, the UK and the US. More specifically, we first analyze the frequency with which China has appeared in news headlines, which is a measure of China’s influence in the world. Second, we build a Naive Bayes classifier to study the evolving nature of the news reports, i.e., whether they are economic or political. We then evaluate the friendliness of the news coverage based on sentiment analysis. Empirical results indicate that there has been increasing news coverage of China in all the countries under study. We also find that the emphasis of the reports is generally shifting towards China’s economy. Here Japan and South Korea are exceptions: they are reporting more on Chinese politics. In terms of global sentiment, the picture is quite gloomy. With the exception of Australia and, to some extent, France, all the other countries under examination are becoming less positive towards China.

Light is Heavy

Por • 21 sep, 2015 • Category: Ciencia y tecnología

Einstein’s relativity theory appears to be very accurate, but at times equally puzzling. On the one hand, electromagnetic radiation must have zero rest mass in order to propagate at the speed of light, but on the other hand, since it definitely carries momentum and energy, it has non-zero inertial mass. Hence, by the principle of equivalence, it must have non-zero gravitational mass, and so, light must be heavy. In this paper, no new results will be derived, but a possibly surprising perspective on the above paradox is given.

A Galois connection between classical and intuitionistic logics. II: Semantics

Por • 21 sep, 2015 • Category: Crítica

Three classes of models of QHC, the joint logic of problems and propositions, are constructed and analyzed, including a class of sheaf models that is closely related to solutions of some actual mathematical problems (such as solutions of algebraic equations) and combines the familiar Leibniz-Euler-Venn semantics of classical logic with a BHK-type semantics of intuitionistic logic. We also describe a first-order theory T over QHC intended to capture the spirit of the ancient Greek tradition of geometry, as presented in Euclid’s “Elements”. The ancients observed, in what was presumably a consensus view emerging from an earlier debate, a distinction between problems and postulates vs. theorems and axioms (which can also be inferred from the grammar of Euclid’s text) and the logical interdependence between the two realms. T formalizes this in terms of the connectives ! and ? of QHC. The purely classical fragment of T is shown to coincide with Tarski’s weak elementary geometry, and the purely intuitionistic one with Beeson’s “intuitionistic Tarski geometry”.

Le problème de la vérité dans Etre et Temps de Heidegger

Por • 21 sep, 2015 • Category: Educacion

The aim of the present paper is to analyse the way in which Heidegger’s work Being and Time is based on the relationship between four concepts with methodological function: phenomenon, logos, interpretation (Auslegung), and truth. This relationship describes the methodological code of the Heideggerian analysis: the definition of the phenomenality, the identification of the only possible phenomenon (being) that satisfy the phenomenological definition and the drafting of the way of access to being. Truth as disclosedness (Erschlossenheit) belongs to the constitution of being of Dasein and it is not primordially a determination of the statements. Dasein is at the same time “in untruth” because the falling prey (Verfallen) belongs equiprimordially to its constitution. In the last part of the paper we identify the main changes of the concept of truth and of the meaning of phenomenality after the Heideggerian Kehre.