The Effect of Corotation on the Radial Gradient of Metallicity of Spiral Galaxies

The corotation radius in a spiral galaxy is the radius where the spiral pattern speed has the same velocity of the rotation curve. By compiling results from the literature for 20 spiral galaxies we verified a strong correlation between the radius of the minima or inflections of the metallicity distribution and the corotation radius.Comment: 3 pages, 1 figur

Metameric MIMO-OOK transmission scheme using multiple RGB LEDs

In this work, we propose a novel visible light communication (VLC) scheme utilizing multiple di erent red green and blue triplets each with a di erent emission spectrum of red, green and blue for mitigating the e ect of interference due to di erent colors using spatial multiplexing. On-o keying modulation is considered and its e ect on light emission in terms of flickering, dimming and color rendering is discussed so as to demonstrate how metameric properties have been considered. At the receiver, multiple photodiodes with color filter-tuned on each transmit light emitting diode (LED) are employed. Three di erent detection mechanisms of color zero forcing, minimum mean square error estimation and minimum mean square error equalization are then proposed. The system performance of the proposed scheme is evaluated both with computer simulations and tests with an Arduino board implementatio

Juan Carlos Marset: Leyenda napolitana

Review of: Juan Carlos Marset, Leyenda napolitana. Barcelona, Tusquets, 1999, 118 pp

June H. Townsend: William Faulkner y Luis Martín-Santos

Review of: June H. Townsend, William Faulkner y Luis Martín-Santos. Madrid, Pliegos, 2000, 201 pp

Felipe Benítez Reyes: Escaparate de venenos (1996-1999)

Review of: Felipe Benítez Reyes. Escaparate de venenos (1996-1999). Barcelona, Tusquets, 2000, 174 pp

Variaciones sobre el autorretrato en la poesía última

La poesía es el espacio donde el yo sucede. Al articularse en términosespaciales instaura un fl uir también temporal: es un cronotopo; y por ende lo essu sujeto –sujetado a dicho devenir–. Por encima de las variantes gramaticalesque adopte el hablante, en el poema se fragua la subjetividad del poeta, desplazada,diferida, suplementada. El autorretrato exhibe ese proceso de recreaciónfi ccional, atento tanto a la «fi gura» como a su «fondo», el contexto histórico y lasconvenciones literarias. Analizamos varios ejemplos de autorretratos poéticosactuales para ver las tensiones entre el efecto de verosimilitud y la búsqueda dedislocación del modelo. Y en esa trama relacional mostraremos su parentescocon la autopoética como tipo discursivo, para exhibir en primer lugar el perfi lartístico del yo, sus motivaciones y proceso creador

Efficient Compressive Sampling of Spatially Sparse Fields in Wireless Sensor Networks

Wireless sensor networks (WSN), i.e. networks of autonomous, wireless sensing nodes spatially deployed over a geographical area, are often faced with acquisition of spatially sparse fields. In this paper, we present a novel bandwidth/energy efficient CS scheme for acquisition of spatially sparse fields in a WSN. The paper contribution is twofold. Firstly, we introduce a sparse, structured CS matrix and we analytically show that it allows accurate reconstruction of bidimensional spatially sparse signals, such as those occurring in several surveillance application. Secondly, we analytically evaluate the energy and bandwidth consumption of our CS scheme when it is applied to data acquisition in a WSN. Numerical results demonstrate that our CS scheme achieves significant energy and bandwidth savings wrt state-of-the-art approaches when employed for sensing a spatially sparse field by means of a WSN.Comment: Submitted to EURASIP Journal on Advances in Signal Processin