Electrónica

Predicting copper price is essential for making decisions that can affect companies and governments dependent on the copper mining industry. Copper prices follow a time series that is nonlinear and non-stationary, and that has periods that change as a result of potential growth, cyclical fluctuation and errors. Sometimes, the trend and cyclical components together are referred to as a trend-cycle. In order to make predictions, it is necessary to consider the different characteristics of a trend-cycle. In this paper, we study a copper price prediction method using support vector regression (SVR). This work explores the potential of the SVR with external recurrences to make predictions at 5, 10, 15, 20 and 30 days into the future in the copper closing price at the London Metal Exchange. The best model for each forecast interval is performed using a grid search and balanced cross-validation. In experiments on real data sets, our results obtained indicate that the parameters (C, ε, γ) o...

Computational simulation is a powerful tool for performance evaluation of computational systems. It is useful to make capacity planning of data center clusters, to obtain profiling reports of software applications and to detect bottlenecks. It has been used in different research areas like large scale Web search engines, natural disaster evacuations, computational biology, human behavior and tendency, among many others. However, properly tuning the parameters of the simulators, defining the scenarios to be simulated and collecting the data traces is not an easy task. It is an incremental process which requires constantly comparing the estimated metrics and the flow of simulated actions against real data. In this work, we present an experimental framework designed for the development of large scale simulations of two applications used upon the occurrence of a natural disaster strikes. The first one is a social application aimed to register volunteers and manage emergency campaigns an...

Modern mining procedures aim to replace human resources directly involved in the mineral extraction process by automatic or remote control systems. Data may be collected from sensors, or data and/or video may be transmitted by telecommunication equipment. The actual technology trend is to do these transmissions using wireless technology (WSN, Wi-Fi, among others). This work summarizes the experience that has been collected from characterizing a Single-Input-Single-Output (SISO) large scale 870 MHz and 2.45 GHz wireless propagation channel in an underground copper mine. Also the Rician K
factor and channel coherence time are calculated for a 2.45 GHz mobile link.

Resumen.-En este trabajo se resume la experiencia adquirida en el Departamento de Electrónica del la UTFSM para la realización de medidas de propagación de señales electromagnéticas en ambientes confinados, en lo relativo a selección de ambientes, ...

The prediction of wall losses is a fundamental aspect in the planning of cellular systems. The broad variety of building materials and construction codes makes accurate attenuation prediction very difficult without the support of detailed structural data and measurements. In this ...