Some comparison theorems for weak nonnegative splittings of bounded operators

AbstractThe comparison of the asymptotic rates of convergence of two iteration matrices induced by two splittings of the same matrix has arisen in the works of many authors. In this paper we derive new comparison theorems for weak nonnegative splittings and weak splittings of bounded operators in a general Banach space and rather general cones, and in a Hilbert space, which extend some of the results obtained by Woźnicki (Japan J. Indust. Appl. Math. 11(1994) 289–342) and Marek and Szyld (Numer. Math. 44(1984) 23–35). Furthermore, we present new theorems also for bounded operator which extend some results by Csordas and Varga (Numer. Math. 44. (1984) 23–35) for weak nonnegative splittings of matrices

Weight-2 input sequences of 1/n convolutional codes from linear systems point of view

Convolutional codes form an important class of codes that have memory. One natural way to study these codes is by means of input state output representations. In this paper we study the minimum (Hamming) weight among codewords produced by input sequences of weight two. In this paper, we consider rate 1/n and use the linear system setting called (A,B,C,D) input-state-space representations of convolutional codes for our analysis. Previous results on this area were recently derived assuming that the matrix A, in the input-state-output representation, is nonsingular. This work completes this thread of research by treating the nontrivial case in which A is singular. Codewords generated by weight-2 inputs are relevant to determine the effective free distance of Turbo codes.The research of the second author was supported by Spanish I+D+i project PID2019-108668GB-I00 of MCIN/AEI/10.13039/501100011033

1/n Turbo codes from linear system point of view

The performance of turbo codes at the error floor region is largely determined by the effective free distance, which corresponds to the minimum Hamming weight among all codeword sequences generated by input sequences of weight two. In this paper, we study turbo codes of dimension one obtained from the concatenation of two equal codes and present an upper bound on the effective free distance of a turbo code with these parameters defined over any finite field. We do that making use of the so-called (A, B, C, D) state-space representations of convolutional codes and restrict to the case where A is invertible. A particular construction, from a linear systems point of view, of a recursive systematic convolutional code of rate 1/n so that the effective free distance of the corresponding turbo code attains this upper bound is also presented.D. Napp was partially supported by the the Universitat d’Alacant (Grant No. VIGROB-287) and Generalitat Valenciana (Grant No. AICO/2017/128). V. Herranz and C. Perea were supported by the Ministerio de Economa, Industria y Competitividad within project TIN2016-80565-R

Mendler-style Iso-(Co)inductive predicates: a strongly normalizing approach

We present an extension of the second-order logic AF2 with iso-style inductive and coinductive definitions specifically designed to extract programs from proofs a la Krivine-Parigot by means of primitive (co)recursion principles. Our logic includes primitive constructors of least and greatest fixed points of predicate transformers, but contrary to the common approach, we do not restrict ourselves to positive operators to ensure monotonicity, instead we use the Mendler-style, motivated here by the concept of monotonization of an arbitrary operator on a complete lattice. We prove an adequacy theorem with respect to a realizability semantics based on saturated sets and saturated-valued functions and as a consequence we obtain the strong normalization property for the proof-term reduction, an important feature which is absent in previous related work.Comment: In Proceedings LSFA 2011, arXiv:1203.542

Parallel concatenated convolutional codes from linear systems theory viewpoint

The aim of this work is to characterize two models of concatenated convolutional codes based on the theory of linear systems. The problem we consider can be viewed as the study of composite linear system from the classical control theory or as the interconnection from the behavioral system viewpoint. In this paper we provide an input–state–output representation of both models and introduce some conditions for such representations to be both controllable and observable. We also introduce a lower bound on their free distances and the column distances

La frontera concejo de Jaén – Reino de Granada en 1476

Los estudios sobre relaciones fronterizas entre moros y cristianos, en general, son muy numerosos y de sobra conocidos, y, en particular para la zona jiennense, los del profesor Juan de Mata Carriazo. Siguiendo el camino trazado por estos estudios, pretendemos mostrar un aspecto más de la vida en la frontera, eligiendo para ello el año 1476 por la cantidad de datos encontrados en el Libro de Actas del Concejo de Jaén correspondiente al citado año, y al hallazgo del texto, hasta hoy desconocido, de la tregua asentada entre el rey de Granada y los reyes de Castilla en este año

Intervención de linajes giennenses en los problemas sucesorios de la segunda mitad del siglo XV

Durante el siglo XV, tanto la monarquía como la aristocracia aumentaron su poder en detrimento del poder ciudadano, y esto por una razón, por “no estar gobernadas (las ciudades) por una representación de sus vecinos e intereses, como había sido la tendencia originaria, sino por oligarquías de pequeños linajes hidalgos y de caballeros cuantiosos”. De dos de estos linajes, los Torres y los Lucas, nos vamos a ocupar, y del papel que ambos jugaron en el reinado de Enrique IV y primeros años del de Isabel I

Calidad de vida en pacientes portadores de prótesis completa

Depto. de Odontología Conservadora y PrótesisFac. de OdontologíaFALSEunpu

Are all Semitic languages immune to letter transpositions? The case of Maltese

Recent research using the rapid serial visual presentation (RSVP) paradigm with English sentences that included words with letter transpositions (e.g., jugde) has shown that participants can readily reproduce the correctly spelled sentences with little cost; in contrast, there is a dramatic reading cost with root-derived Hebrew words (Velan & Frost, Psychonomic Bulletin & Review 14:913–918, 2007, Cognition 118:141–156, 2011). This divergence could be due to (1) the processing of root-derived words in Semitic languages or (2) the peculiarities of the transitional probabilities in root-derived Hebrew words. Unlike Hebrew, Maltese is a Semitic language that does not omit vowel information in print and whose morphology also has a significant non-Semitic (mostly Romance) morphology. Here, we employed the same RSVP technique used by Velan and Frost (Psychonomic Bulletin & Review 14:913–918, 2007, Cognition 118:141–156, 2011), this time with Maltese (and English) sentences. The results showed that Maltese–English bilinguals were able to reproduce the Maltese words—regardless of whether they were misspelled (involving the transposition of two letters from the consonantal root) or not, with no reading cost—just as in English. The apparent divergences between the RSVP data with Hebrew versus Maltese sentences are likely due to the combination of the characteristics of the Hebrew orthographic system with the Semitic morphology.peer-reviewe