Search results for "Economia matemàtica"
showing 6 items of 6 documents
Axiomatic characterization of the weighted solidarity values
2014
Abstract We define and characterize the class of all weighted solidarity values . Our first characterization employs the classical axioms determining the solidarity value (except symmetry ), that is, efficiency , additivity and the A-null player axiom , and two new axioms called proportionality and strong individual rationality . In our second axiomatization, the additivity and the A-null player axioms are replaced by a new axiom called average marginality .
wavScalogram : an R package with scalogram wavelet tools for time series analysis
2022
In this work we present the wavScalogram R package, which contains methods based on wavelet scalograms for time series analysis. These methods are related to two main wavelet tools: the windowed scalogram difference and the scale index. The windowed scalogram difference compares two time series, identifying if their scalograms follow similar patterns at different scales and times, and it is thus a useful complement to other comparison tools such as the squared wavelet coherence. On the other hand, the scale index provides a numerical estimation of the degree of non-periodicity of a time series and it is widely used in many scientific areas.
Selección automática de una cartera óptima a partir de datos importados de Internet. Una aplicación VBA.
2015
RESUMEN Según el Programa Básico de Estudios ("Core Syllabus") para la formación actuarial en Europa, la formación de un actuario de seguros exige que los estudios conducentes a la capacitación profesional otorguen al estudiante "un conocimiento práctico, aplicado, de las modernas tecnologías de la información y la comunicación". En esta comunicación se presenta una aplicación docente realizada con Visual Basic Aplicado en la que se ha implementado un modelo de selección de cartera óptima clásico, utilizando las herramientas de optimización y de importación de datos que proporciona Excel. La cartera contempla a los activos del IBEX-35 y se ha programado el cálculo automático de lacomposició…
An entropy-based machine learning algorithm for combining macroeconomic forecasts
2019
This paper applies a Machine Learning approach with the aim of providing a single aggregated prediction from a set of individual predictions. Departing from the well-known maximum-entropy inference methodology, a new factor capturing the distance between the true and the estimated aggregated predictions presents a new problem. Algorithms such as ridge, lasso or elastic net help in finding a new methodology to tackle this issue. We carry out a simulation study to evaluate the performance of such a procedure and apply it in order to forecast and measure predictive ability using a dataset of predictions on Spanish gross domestic product.
A New Wavelet Tool to Quantify Non-Periodicity of Non-Stationary Economic Time Series
2020
We introduce a new wavelet tool, the windowed scale index, to study the degree of non-periodicity of time series. The windowed scale index is based on some recently defined tools, such as the windowed scalogram and the scale index. This novel measure is appropriate for non-stationary time series whose characteristics change over time and, therefore, it can be applied to a wide variety of disciplines. Furthermore, we revise the concept of the scale index and pose a theoretical problem: it is known that if the scale index of a function is not zero then it is non-periodic, but if the scale index of a function is zero, then it is not proved that it has to be periodic. This problem is solved for…
An evaluation of the environmental factors for supply chain strategy decisions using grey systems and composite indicators
2020
[EN] The purpose of this work is to assess the importance of environmental factors in a supply chain with four partners as a preliminary step to select the competitive strategies and objectives. To achieve this purpose, a real case study was carried out in a footwear supply chain, in which two approaches were used: the grey system theory and uncertainty analysis tools for composite indicators. In order to validate both approaches, a seven-phase research methodology was developed and applied to our case study. In addition, the priorization of environmental factors was calculated individually for each partner. The results allow managers to establish the competitive strategy that best suits th…