Juan Antonio Morente-Molinera

The sequence of Schumann resonances is unique for each celestial body with an ionosphere, since these resonances are determined by the dimensions of the planet/satellite and the corresponding atmospheric conductivity profile. Detecting these frequencies in an atmosphere is a clear proof of electrical activity, since it implies the existence of an electromagnetic energy source, which is essential for their creation and maintenance. In this paper, an analysis procedure for extracting weak resonances from the responses of electromagnetic systems excited by electric discharges is shown. The procedure, based on analysis of the late-time system response, is first checked using an analytical function and later applied to the vertical electric field generated by the computational simulation of Earth's atmosphere using the TLM (Transmission Line Matrix) method in order to extract the weak Schumann resonances contained in this electric field component.

Nowadays, smartphones have become indispensable items for everybody. Thanks to them, people can communicate and access Internet at any time regardless of where they are located. New smartphones be-longing to a high amount of labels and with different features and prices keep appearing constantly in the market. This way, there is a need of tools that help buyers to select and buy the smartphone that better fits their necessities. In this article, a decision support system build over a fuzzy ontology has been designed in order to help people to select the perfect smartphone for them. Linguistic labels are used in order to pro-vide the buyer with a comfortable way of expressing himself/herself.

ABSTRACT Rapid changes in the business environment such us the globalization as well as the increasing necessity to make crucial decisions involving a huge range of alternatives in short period of time or even in real time have made that computerized group decision support systems become very useful tools. However in the majority of the cases the panel of experts cannot provide all the information about their preferences due to different reasons such as lack of knowledge, time etc. Therefore different approaches have been presented to deal with the missing preferences in group decision making contexts. In this paper we review and analyse the state-of-the-art research efforts carried out on this topic for incomplete fuzzy preference relations and multiplicative preference relations.