210 research outputs found
The pathophysiology of motor thalamus
The thalamus is considered an important structure of sensitive pathways, and also intervenes in motor tasks. It receives multiple cortical and subcortical afferent fibers and the relations between their different nuclei are intense. After anatomic and functional study of the thalamic structure and its connections, we will analyze the different classifications and proposed subdivisions of the thalamic nuclear groups both in primates and humans. We will direct our study towards those aspects of the thalamus related to movement. The motor thalamus is described in most non-human primate studies as the thalamic region that receives subcortical afferent fibers from the basal ganglia and the cerebellum, and cortical fibers of the primary motor and pre-motor areas and these functions are also inferred to the human thalamus based on the cytoarchitectonic similarity between them. Later on, the pathological clinical aspects related to the motor thalamus are discussed. Disturbances or impairments in the coordination and course of movement, in muscular tone, and movement planning can be associated with injuries located in the motor thalamus and its connections. The research related to surgical procedures involving the thalamic structure for the treatment of impairments or disturbances of motion and movement are examined and will permit a comprehensive summary of the different mechanisms involved in the pathophysiology of the motor thalamus.peer-reviewe
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
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
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
Plan estratégico de comunicación para la mejora de la visibilidad de Revista Mediterránea de Comunicación
Revista Mediterránea de Comunicación está consolidándose dentro de las revistas de publicación científica. En este Trabajo Fin de Máster, se desarrollará un Plan Estratégico de Comunicación para mejorar su difusión y visibilidad a nivel internacional. Al ser una revista de reciente creación, con sesgos en aspectos clave para su desarrollo, las acciones que siguen a este PEC orientarán a la revista hacia una presencia internacional y una mayor accesibilidad de los usuarios. Su difusión en red como en soportes offline, así como la postulación a diferentes bases de datos, dará como resultado el alcance que RMC necesita para que siga desarrollándose dentro del campo científico de las Ciencias Sociales y la Comunicación. Así mismo, este plan pretende concienciar a la comunidad científica de su responsabilidad en la difusión del conocimiento a la población general, y de la necesidad de adaptar su discurso para facilitar la comprensión y apropiación social del conocimiento
Las matrices de Toeplitz en la construcción de códigos convolucionales perforados
En este trabajo presentamos la modelización de la técnica de perforación de códigos convolucionales introducida por McEliece desde el punto de vista de sistemas. Aplicando esta técnica a un (2, 1, 1)-código convolucional óptimo y teniendo en cuenta las propiedades de las matrices de Toeplitz, construimos un nuevo (3, 2, 1)-código óptimo
El valle nos toca : una mirada al pasado, el presente y el futuro del Valle del Cauca desde su patrimonio cultural
Comunicador (a) SocialPregrad
Psychopathology in obstructive sleep apnea : the role of severity of the apnea / hypopnea index
info:eu-repo/semantics/publishedVersio
Double Dissociations in the Processing of Conceptual Relations
The aim of the present paper is to analyze if taxonomic and thematic conceptual relations are processed primarily in the linguistic system, in the simulation system or in both. Because the verbal modality is the best way to access the linguistic system and the pictorial modality is the best way to access the simulation system (Barsalou, 1999), we studied these processes through verbal and pictorial tasks. We studied a group of 60 patients with focal brain lesions to explore the presence of double dissociation, based on the assumption that such patients will reveal the existence of independent processes according to conceptual relation type and the modality in which information is presented (verbal vs. pictorial). The results reveal the presence of double dissociations in the processing of thematic relations, but not in taxonomic relations. This suggests that there may be two ways to store relations of this type: through the co-occurrence of words in language or through the joint representation of both objects in a contextual representation. The thematic relations may be primordially stored within one of the two systems (linguistic and simulation) or both. Taxonomic relations, on the other hand, are principally processed in the simulation system.Fil: Vivas, Leticia Yanina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Mar del Plata. Facultad de Psicología. Centro De Investigación en Procesos Básicos, Metodologías y Educación; ArgentinaFil: García García, Ricardo. Universidad de Salamanca; EspañaFil: Vivas, Jorge Ricardo. Universidad Nacional de Mar del Plata. Facultad de Psicología. Centro De Investigación en Procesos Básicos, Metodologías y Educación; ArgentinaFil: Perea Bartolomé, Maria Victoria. Universidad de Salamanca; Españ
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