Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

This research puts into context statistical multivariate methods in the political arena, making the first contribution to the analysis of Ecuadorian politics on the definition of elected mayors’ profile. In this regard, a logistic regression model was estimated to describe voters’ preferences in terms of candidates’ age, gender and political organization; and, a CHAID decision tree was built to delve into the preferred features depending on the political party. This latter analysis revealed interesting differences that also help to describe Ecuadorian political reality. The sample upon which the profiles were built included the voters’ preferences from the four most populated Ecuadorian provinces in the mayors’ election in 2014. This analysis combines the application of statistics in the political science field and proposes to be the first step for future research to analyze how the preferred profile of elected candidates changes over time.

Initially, the article presents a brief synthesis about certain types of linear functional equations of ℂ2 in the bicircle and its solution search scheme. Then we have a detailed study of a certain type linear functional equation with kernel

In this paper we show a formal approach for the classification problem and a schematization for its resolution. We take the study case of the classification of the quadratic equation of two unknowns in order to illustrate the given procedure. With this, we propose a didactic approach to the methodology exposed for the classificationproblem which could be used by docents of university freshman students in their classes.

In  this  presentation  we  construct  a  theory-based  numericalmethod  for  starting  the  continuation  of  homoclinic  tangenciasnear 1 : 1 resonances, for systems with arbitrary dimension ≥ 2. The method is based on numerical center manifold reduction and flow approximation. The effectiveness of the method is illustrated by numerical examples.

In the present work we analyze the conditions and formulas for the general solution of particular cases of the linear functional equation A(z,w)ξ(z,w)−A(z,0)ξ(z,0)−A(0,w)ξ(0,w)+A(0,0)ξ(0,0)=zwη(z,w),|z|≤1,|w|≤1,with

The flow of water through the soil is modeled mathematically by the Richards equation. This doubly degenerate nonlinear equation is difficult to solve, even more nonlinearity and degeneration make the design of numerical schemes for this problem a challenging task. According to the literature, the implicit methods are the ones that give the best results since the schemes obtained allow to simulate the degenerate problem, however these produce nonlinear problems that must be solved by means of linearization methods. In this investigation a new numerical scheme of linearization of the Richards equation is developed. A totally implicit Euler scheme is used to discretize time and finite elements to discretize space, however, these schemes should work for any spatial discretization chosen. A more robust and faster scheme was achieved (in terms of number of iterations and total machine time used) than those already existing.

In this paper we study the conditions that a pair of defined functions must have in a metric space to guarantee the existence of a single fixed point in common among them. The results proposed for several authors are analyzed. In addition, a generalization of some of these results is presented.

Based on physical arguments, we find the position, momentum, and kinetic energy operators in the interval (0, ℓ) of the real line. We characterize the domain of the canonical commutation rule (between position and momentum operators) and the validity of the uncertainty principle.

Resource Efficiency and Cleaner Production strategies were implemented in a pallet manufacturer sawmill in order to observe their effect on productivity and the environment. The main goal was to inform Small and Medium Enterprises the advantages of a sustainable and green production and to encourage them to invest in Resource Efficiency and Cleaner Production strategies. In the context of Resource Efficiency and Cleaner Production, the Best Management Practices are the first low cost and easy to apply measures to transform the current industrial system into a more sustainable and green industrial system. A longitudinal research approach was used. The investigation was performed in three phases: diagnosis, selection of measures to overcome the identified problems, and implementation and evaluation of results. Once the wood companies’ diagnostic data was collected for three months, surveys were conducted with the managers and workers of “Maderol” which served as a pilot sawmill where the Best Management Practices were applied. A survey with closed yes/no-questions and a non-structured interview were conducted. Based on this information, Best Management Practices measures were identified and implemented for a test period of three months. Results were analyzed based on the economic data of the sawmill and a second survey after the test period. The results obtained from our study on a pallet manufacturer sawmill located in the city of Puyo-Ecuador confirm that the Best Management Practices can provide clear and specific guidance to Small and Medium Enterprises so that they can quickly improve their production efficiency and reduce their negative impact on the environment.

Vibrational spectroscopy approaches like FT-IR and FT-Raman, as analytical method, can be used to assess chemical changes in historical wood structures. In this study, wood samples of three historical buildings, in Gorgan, Iran, namely Tekie Estebar, Molla Esmaiel Mosque, and the Esmaieli Buildings were selected. Wood species was determined by their macroscopic characteristics which were hornbeam (Carpinus betulus), oak (Quercus castaneifolia), beech (Fagus orientalis), and elm (Ulmus glabra), as hardwood species, and yew (Taxus baccata) as a softwood species. Also, some samples of oak were collected from northern and southern sides of the Esmaieli Building in order to compare deterioration environmental factors.. The approximate assignment of the experimental bands was completed by comparing. For this purpose, the experimental bands with the calculated band frequencies of cellulose, hemicellulose and lignin. In addition, the reported assignment for softwood and hardwood was used to confirm the vibrational assignments. The results of spectroscopy revealed that biodegradation had occurred in all species. Comparison between the most important vibrational band frequencies related to carbohydrates and lignin in hardwood species suggested that degradation of carbohydrates was greater than lignin, which could be attributed to brown rot and hydrolysis. Reduction of chemical compounds in south oak samples was higher and could be associated with prevailing wind and UV ray in this side. In the only softwood species (yew), because of its highest exposure to frequent raining, deterioration was observed in both carbohydrates and lignin.