Interacciones simétricas y asimétricas y déficit socio-afectivo.

Profundizar en el conocimiento lingüístico y comunicativo de niños con desajustes afectivos en su vida familiar. Ofrecer opciones de intervención social y educativa, para optimizar el desarrollo de los niños con problemas interactivos y comunicativos por su crianza en instituciones. 150 niños en edades comprendidas entre dos y seis años; 120 madres. El trabajo está dividido en capítulos: I y II dedicado a la fundamentación teórica profundizando en los análisis comunicativos y lingüísticos, integrando dos líneas de investigación: la del desarrollo del lenguaje en ambientes de adaptación y la socio-afectiva. III y IV procedimiento experimental: se diseñaron dos situaciones de interacción habituales en la vida de los niños: mirar un cuento y jugar con juguetes simbólicos. La muestra de sujetos se midió de forma repetida: dos veces mirando un cuento (con su madre y con una extraña adulta) y tres veces jugando (con su madre, con una extraña adulta y con un igual). Estas interacciones se filman con un vídeo y eran anotadas en una ficha de referencia para cada sujeto. Las variables seleccionadas son: -Independientes: relaciones afectivas con la madre, una extraña y otro niño, utilizando dos sistemas de control de ésta (tiempo de estancia en el hogar; comparación entre las relaciones asimétricas con la madre y una extraña ante la misma tarea, y las simétricas ante otro niño); edad y sexo. -Dependientes: lingüísticas, comunicativas, episodios, análisis pragmático (cuento y juego) modalidades gestuales y de acción. Los niños externos, no sometidos a ningún régimen institucional, muestran un comportamiento más alto y de mejor nivel en las diferentes categorías de análisis: dedican más cantidad de tiempo a hablar durante la interacción y emiten mayor número de palabras y de enunciados. En la interaccion simétrica los niños internos preguntan significativamente más que los medio-pensionistas, dedicando más cantidad de tiempo a hablar, acompañando la actividad lúdica con el lenguaje. Se comprueba la adquisición progresiva de la competencia lingüística y comunicativa del niño, a medida que aumenta su edad, así como las características variables de la sincronización de los sistemas comunicativos de niños y adultos de la cual resulta el proceso de adquisición del lenguaje. Se encuentra una mayor tendencia a actuar conjuntamente entre los niños mayores y más acción paralela y aislada en los pequeños. Se da una mayor cantidad de tiempo hablado en las interacciones con iguales, que en las relaciones con la madre.

Por que cantam os pastores? Uma interpretação do gênero bucólico latino, sob a perspectiva da prosódia e da métrica

A quantidade vocálica é traço fundamental da prosódia em língua latina e, embora não seja usualmente aproveitada na leitura de poemas, é o dado mais relevante de sua natureza e constituição, visto que, sem ela, não há versos na antiguidade clássica. A quantidade é, assim, fundamental para o canto poético dos pastores, praticado na poesia bucólica, cujo paradigma, instaurado por Teócrito nos Idílios, tem em Virgílio um digno continuador. Nos poemas bucólicos virgilianos, é comum o poeta retratar pastores alternando cantos entre si, forma poética conhecida como amebeu. O objetivo deste artigo é, pois, o de fazer uma leitura de tal topos literário, tendo como ponto de partida a relação intertextual que se funda na derivação genérica, de Teócrito a Virgílio, mas também e principalmente a que se obtém pela leitura integrada da prosódia e da métrica latinas ao texto poético, tendo em vista não apenas os códigos específi cos do gênero bucólico, mas sobretudo os dados que, inferidos da realidade moderna, como os que nos apresenta o lingüista e romancista Gavino Ledda, podem ser aproximados da realidade dos antigos guardadores de rebanho da Sicília – cenário comum aos dramas do universo pastoril virgiliano – ao mesmo tempo que se estuda como quantidade vocálica e ritmo verbal atuam para consubstanciá-lo e dar-lhe expressão poética característica.

(v, k, λ) Configurations and self-dual codes

The incidence matrix of a (v, k, λ) configuration is used to construct a (2v, v) and a (2v + 2, v + 1) self-dual code. If the incidence matrix is a circulant, the codes obtained are quasi-cyclic and extended quasi-cyclic, respectively. The weight distributions of some codes of this type are obtained.

On BCH codes over arbitrary integer rings

Bose-C-Hocquenghem (BCH) atdes with symbols from an arbitrary fhite integer ring are derived in terms of their generator polynomials. The derivation is based on the factohation of x to the power (n) - 1 over the unit ring of an appropriate extension of the fiite integer ring. lke eomtruetion is thus shown to be similar to that for BCH codes over fink flelda.

On Network-Error Correcting Convolutional Codes under the BSC Edge Error Model

Convolutional network-error correcting codes (CNECCs) are known to provide error correcting capability in acyclic instantaneous networks within the network coding paradigm under small field size conditions. In this work, we investigate the performance of CNECCs under the error model of the network where the edges are assumed to be statistically independent binary symmetric channels, each with the same probability of error pe(0 <= p(e) < 0.5). We obtain bounds on the performance of such CNECCs based on a modified generating function (the transfer function) of the CNECCs. For a given network, we derive a mathematical condition on how small p(e) should be so that only single edge network-errors need to be accounted for, thus reducing the complexity of evaluating the probability of error of any CNECC. Simulations indicate that convolutional codes are required to possess different properties to achieve good performance in low p(e) and high p(e) regimes. For the low p(e) regime, convolutional codes with good distance properties show good performance. For the high p(e) regime, convolutional codes that have a good slope ( the minimum normalized cycle weight) are seen to be good. We derive a lower bound on the slope of any rate b/c convolutional code with a certain degree.

Combinatorial Representations of Block Codes

We look at graphical descriptions of block codes known as trellises, which illustrate connections between algebra and graph theory, and can be used to develop powerful decoding algorithms. Trellis sizes for linear block codes are known to grow exponentially with the code parameters. Of considerable interest to coding theorists therefore, are more compact descriptions called tail-biting trellises which in some cases can be much smaller than any conventional trellis for the same code . We derive some interesting properties of tail-biting trellises and present a new decoding algorithm.

Interference Alignment in Regenerating Codes for Distributed Storage: Necessity and Code Constructions

Regenerating codes are a class of recently developed codes for distributed storage that, like Reed-Solomon codes, permit data recovery from any arbitrary of nodes. However regenerating codes possess in addition, the ability to repair a failed node by connecting to any arbitrary nodes and downloading an amount of data that is typically far less than the size of the data file. This amount of download is termed the repair bandwidth. Minimum storage regenerating (MSR) codes are a subclass of regenerating codes that require the least amount of network storage; every such code is a maximum distance separable (MDS) code. Further, when a replacement node stores data identical to that in the failed node, the repair is termed as exact. The four principal results of the paper are (a) the explicit construction of a class of MDS codes for d = n - 1 >= 2k - 1 termed the MISER code, that achieves the cut-set bound on the repair bandwidth for the exact repair of systematic nodes, (b) proof of the necessity of interference alignment in exact-repair MSR codes, (c) a proof showing the impossibility of constructing linear, exact-repair MSR codes for d < 2k - 3 in the absence of symbol extension, and (d) the construction, also explicit, of high-rate MSR codes for d = k+1. Interference alignment (IA) is a theme that runs throughout the paper: the MISER code is built on the principles of IA and IA is also a crucial component to the nonexistence proof for d < 2k - 3. To the best of our knowledge, the constructions presented in this paper are the first explicit constructions of regenerating codes that achieve the cut-set bound.

Asymptotically-good, multigroup decodable space-time block codes

For a family of Space-Time Block Codes (STBCs) C-1, C-2,..., with increasing number of transmit antennas N-i, with rates R-i complex symbols per channel use, i = 1, 2,..., we introduce the notion of asymptotic normalized rate which we define as lim(i ->infinity) R-i/N-i, and we say that a family of STBCs is asymptotically-good if its asymptotic normalized rate is non-zero, i. e., when the rate scales as a non-zero fraction of the number of transmit antennas. An STBC C is said to be g-group decodable, g >= 2, if the information symbols encoded by it can be partitioned into g groups, such that each group of symbols can be ML decoded independently of the others. In this paper we construct full-diversity g-group decodable codes with rates greater than one complex symbol per channel use for all g >= 2. Specifically, we construct delay-optimal, g-group decodable codes for number of transmit antennas N-t that are a multiple of g2left perpendicular(g-1/2)right perpendicular with rate N-t/g2(g-1) + g(2)-g/2N(t). Using these new codes as building blocks, we then construct non-delay-optimal g-group decodable codes with rate roughly g times that of the delay-optimal codes, for number of antennas N-t that are a multiple of 2left perpendicular(g-1/2)right perpendicular, with delay gN(t) and rate Nt/2(g-1) + g-1/2N(t). For each g >= 2, the new delay-optimal and non-delay- optimal families of STBCs are both asymptotically-good, with the latter family having the largest asymptotic normalized rates among all known families of multigroup decodable codes with delay T <= gN(t). Also, for g >= 3, these are the first instances of g-group decodable codes with rates greater than 1 reported in the literature.

On t-designs and bounds relating query complexity to error resilience in locally correctable codes

An n-length block code C is said to be r-query locally correctable, if for any codeword x ∈ C, one can probabilistically recover any one of the n coordinates of the codeword x by querying at most r coordinates of a possibly corrupted version of x. It is known that linear codes whose duals contain 2-designs are locally correctable. In this article, we consider linear codes whose duals contain t-designs for larger t. It is shown here that for such codes, for a given number of queries r, under linear decoding, one can, in general, handle a larger number of corrupted bits. We exhibit to our knowledge, for the first time, a finite length code, whose dual contains 4-designs, which can tolerate a fraction of up to 0.567/r corrupted symbols as against a maximum of 0.5/r in prior constructions. We also present an upper bound that shows that 0.567 is the best possible for this code length and query complexity over this symbol alphabet thereby establishing optimality of this code in this respect. A second result in the article is a finite-length bound which relates the number of queries r and the fraction of errors that can be tolerated, for a locally correctable code that employs a randomized algorithm in which each instance of the algorithm involves t-error correction.

Analysis and retrofitting design of a single-span R.C. bridge

This paper deals with the case history of a damaged one-span prestressed concrete bridge on a crucial artery near the city of Cagliari (Sardinia), along the sea-side. After being involved in a disastrous flood, attention has arisen on the worrying safety state of the deck, submitted to an intense daily traffic load. Evident signs of this severe condition were the deterioration of the beams concrete and the corrosion, the lack of tension and even the rupture of the prestressing cables. After performing a limited in situ test campaign, consisting of sclerometer, pull out and carbonation depth tests, a first evaluation of the safety of the structure was performed. After collecting the data of dynamic and static load tests as well, a comprehensive analysis have been carried out, also by means of a properly calibrated F.E. model. Finally the retrofitting design is presented, consisting of the reparation and thickening of the concrete cover, providing flexural and shear FRP external reinforcements and an external prestressing system, capable of restoring a satisfactory bearing capacity, according to the current national codes. The intervention has been calibrated by the former F.E. model with respect to transversal effects and influence of local and overall deformation of reinforced elements. © 2012 Taylor & Francis Group.