Event Recognition Using Signal Spectrograms in Long Pulse Experiments

As discharge duration increases, real-time complex analysis of the signal becomes more important. In this context, data acquisition and processing systems must provide models for designing experiments which use event oriented plasma control. One example of advanced data analysis is signal classification. The off-line statistical analysis of a large number of discharges provides information to develop algorithms for the determination of the plasma parameters from measurements of magnetohydrodinamic waves, for example, to detect density fluctuations induced by the Alfvén cascades using morphological patterns. The need to apply different algorithms to the signals and to address different processing algorithms using the previous results necessitates the use of an event-based experiment. The Intelligent Test and Measurement System platform is an example of architecture designed to implement distributed data acquisition and real-time processing systems. The processing algorithm sequence is modeled using an event-based paradigm. The adaptive capacity of this model is based on the logic defined by the use of state machines in SCXML. The Intelligent Test and Measurement System platform mixes a local multiprocessing model with a distributed deployment of services based on Jini

Understanding the impact of line-of-sight in the ergodic spectral efficiency of cellular networks

In this paper we investigate the impact of lineof-sight (LoS) condition in the ergodic spectral efficiency of cellular networks. To achieve this goal, we have considered the kappa-mu shadowed model, which is a general model that provides an excellent fit to a wide set of propagation conditions. To overcome the mathematical complexity of the analysis, we have split the analysis between large and small-scale effects. Building on the proposed framework, we study a number of scenarios that range from heavily-fluctuating LoS to deterministic-LoS. Finally, we shed light on the interplay between fading severity and spectral efficiency by means of the amount of fading.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Spontaneous Symmetry Breakdown in non-relativistic Quantum Mechanics

The advantages and disadvantages of some pedagogical non-relativistic quantum-mechanical models, used to illustrate spontaneous symmetry breakdown, are discussed. A simple quantum-mechanical toy model (a spinor on the line, subject to a magnetostatic interaction) is presented, that exhibits the spontaneous breakdown of an internal symmetry.Comment: 19 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:1111.1213. Equations (30) and (31) have been corrected. Other minor correction

Chemical and structural changes of calcium ion exchange silica pigment in 0.5M NaCl and 0.5M Na 2SO4 solutions

This paper studies the suitability of an environmentallyfriendly anticorrosive pigment (Si/Ca) to replace Cr(VI) pigments, characterising the initial pigment and the products obtained after interaction with aqueous solutions containing aggressive ions from a corrosion viewpoint (Cl - and SO42- ). X-ray diffraction (XRD), calorimetry (DTATG), Fourier transform IR spectroscopy (FTIR) and scanningelectron microscopy (SEM-EDAX) techniques areused. The ion exchange capacity of the pigment is studied and the solutions obtained after the pigment-solution interaction are analysed. The results obtained show that a series of physical/chemical transformations take place in the pigment on interaction with the Cl - and SO42-  solutions, in some cases accompanied by the appearance of new crystalline phases, mainly calcium and sodium silicates and calcium sulphate. Analysis of the solutions obtained after interaction shows a rise in the calcium content as theionic force of the medium increases. These results suggest that the mechanism by which the pigment acts is not only based on ion exchange reactions but also on a structural modification of the pigment itself and consequently on (co)precipitation reactions that form insoluble compounds in the studied aggressive media

Joint Distribution of Distance and Angles in Finite Wireless Networks

Directional beamforming will play a paramount role in 5G and beyond networks in order to combat the higher path losses incurred at millimeter wave bands. Appropriate modeling and analysis of the angles and distances between transmitters and receivers in these networks are thus essential to understand performance and limiting factors. Most existing literature considers either infinite and uniform networks, where nodes are drawn according to a Poisson point process, or finite networks with the reference receiver placed at the origin of a disk. Under either of these assumptions, the distance and azimuth angle between transmitter and receiver are independent, and the angle follows a uniform distribution between $0$ and $2\pi$. Here, we consider a more realistic case of finite networks where the reference node is placed at any arbitrary location. We obtain the joint distribution between the distance and azimuth angle and demonstrate that these random variables do exhibit certain correlation, which depends on the shape of the region and the location of the reference node. To conduct the analysis, we present a general mathematical framework which is specialized to exemplify the case of a rectangular region. We then also derive the statistics for the 3D case where, considering antenna heights, the joint distribution of distance, azimuth and zenith angles is obtained. Finally, we describe some immediate applications of the present work, including the analysis of directional beamforming, the design of analog codebooks and wireless routing algorithms.Comment: 14 pages, 14 figure

Further Improvements in SOVA for High-Throughput Parallel Turbo Decoding.

In this letter, we present two mechanisms based on soft-output Viterbi algorithm (SOVA) technique that achieve a performance close to maximum a-posteriori (MAP) decoding. First, we propose a new technique called alternating direction SOVA, which allows for improving the performance of SOVA in similar terms as bidirectional SOVA while barely affecting the area complexity. Then, we introduce the idea of parallel turbo decoding based on path metric/state border exchange. Unlike other techniques, overlapping between adjacent subblocks is not required, thus reducing the decoding latency dramatically. We evaluate their performance in the context of 3GPP-LTE, showing that the combination of both mechanisms achieves a BER performance close to parallel MAP decoding while having a lower complexit