Analytical approximations to the spectra of quark-antiquark potentials

A method, recently devised to obtain analytical approximations to certain classes of integrals, is used in combination with the WKB expansion to derive accurate analytical expressions for the spectrum of quantum potentials. The accuracy of our results is verified by comparing them both with the literature on the subject and with the numerical results obtained with a Fortran code. As an application of the method that we propose, we consider the meson spectroscopy with various phenomenological potentials.Comment: 12 pages, 4 figures, 1 tabl

Duality and exact correlations for a model of heat conduction

We study a model of heat conduction with stochastic diffusion of energy. We obtain a dual particle process which describes the evolution of all the correlation functions. An exact expression for the covariance of the energy exhibits long-range correlations in the presence of a current. We discuss the formal connection of this model with the simple symmetric exclusion process.Comment: 19 page

International Portfolio Diversification: Short-Term Financial Assets and Gold

Using a continuous-time finance-theoretic framework, this paper presents the optimal portfolio rule of an international investor who consumes N national composite goods and who holds N domestic-currency-denominated assets with known nominal interest rates in an environment where prices of goods, assets and exchange rates follow geometric Brownian motion. It is shown that the currency portfolio rule described in Macedo (1982a) is applicable to the case where there are N assets with a known price and one asset, gold, with a random rice in terms of the numeraire. Under these assumptions, it is found that the optimal portfolio of an investor consuming goods from all major industrialized countries (according to their weight in total trade) would be dominated in March 1981 by long positions in U.S. dollars (25%), yen (17%), D. marks (16%), French francs (15%) and pounds sterling (10%). An investor consuming only U.S. goods, by contrast, would hold 96% of his optimal portfolio in U.S. dollars. Because of the covariance of exchange rates and gold, the exclusion of the latter generates substantial reshuffling. The analysis of the evolution of portfolios over time shows that shares changed dramatically at the beginning of the period and did not begin to approach their March 1981 values until the end of 1975. In the case of the yen and the pound there were oscillations throughout the period. With respect to the dollar share in the optimal portfolio of the U.S. and international investor, it is found that, in the period between late 1974 and mid-1976, a period in which the dollar is considered to have been "strong", a large decline in its optimal share took place.

Distribution-Based Categorization of Classifier Transfer Learning

Transfer Learning (TL) aims to transfer knowledge acquired in one problem, the source problem, onto another problem, the target problem, dispensing with the bottom-up construction of the target model. Due to its relevance, TL has gained significant interest in the Machine Learning community since it paves the way to devise intelligent learning models that can easily be tailored to many different applications. As it is natural in a fast evolving area, a wide variety of TL methods, settings and nomenclature have been proposed so far. However, a wide range of works have been reporting different names for the same concepts. This concept and terminology mixture contribute however to obscure the TL field, hindering its proper consideration. In this paper we present a review of the literature on the majority of classification TL methods, and also a distribution-based categorization of TL with a common nomenclature suitable to classification problems. Under this perspective three main TL categories are presented, discussed and illustrated with examples

Fichte and the Body in Action

This paper deals with some fundamental aspects of Fichte’s transcendental account of the body in action, as laid down in the introductory remarks to his 1798 Sittenlehre. Fichte claims that the representation of one’s body is part and parcel of the representation of “first-person” efficacious action or of one’s Wirksamkeit überhaupt. In his view, the latter cannot take place without the former, so that the representation of one’s body is necessarily contained and posited in the representation of one’s Wirksamkeit. Conversely, action – i. e. meine Wirksamkeit – is more than just a particular feature of one’s body among many others: the representation of one’s efficacious action is rather the framework within which the representation of one’s body is formed – it is what constitutes one’s body (my body) as such. This paper tries to zoom in on the very complex set of representations that, according to Fichte, are entailed in the indissoluble unity of this fundamental representation: “my efficacious action/my body”

THE IMPACT OF DE-REGULAMENTATION ON THE BRAZILIAN BANKING INDUSTRY: A PRODUCTION METAFRONTIER APPROACH

This paper analyzes the impact after the entry and the increase in the capital participation of foreign banks in the Brazilian financial institutions. In this sense, taking into account three sub-sets of banks by controlling capital origin - domestic privates, foreigner and public-, an analysis was carried out to find out whether there were technical efficiency and productivity gains in Brazil' banking industry. Therefore, a production frontier was built using the Data Envelopment Analysis (DEA) which allows for the calculation of technical efficiency. Next, performing one of these measures, Malmquist's total productivity index is calculated. The results showed that the technical efficiency of the Brazilian banking industry has not evolved as must as it has been expected, although a total productivity increase has actually occurred, arising only from the technological progress. The foreign banks earned the most productivity gains followed by the domestic private banks. The technological leadership (test), proposed by Marinho and Benegas (2002), showed that the domestic private banks determined the industry's technological pattern.