Speaker identification using models for phonemes

Motivation for Speaker recognition work is presented in the first part of the thesis. An exhaustive survey of past work in this field is also presented. A low cost system not including complex computation has been chosen for implementation. Towards achieving this a PC based system is designed and developed. A front end analog to digital convertor (12 bit) is built and interfaced to a PC. Software to control the ADC and to perform various analytical functions including feature vector evaluation is developed. It is shown that a fixed set of phrases incorporating evenly balanced phonemes is aptly suited for the speaker recognition work at hand. A set of phrases are chosen for recognition. Two new methods are adopted for the feature evaluation. Some new measurements involving a symmetry check method for pitch period detection and ACE‘ are used as featured. Arguments are provided to show the need for a new model for speech production. Starting from heuristic, a knowledge based (KB) speech production model is presented. In this model, a KB provides impulses to a voice producing mechanism and constant correction is applied via a feedback path. It is this correction that differs from speaker to speaker. Methods of defining measurable parameters for use as features are described. Algorithms for speaker recognition are developed and implemented. Two methods are presented. The first is based on the model postulated. Here the entropy on the utterance of a phoneme is evaluated. The transitions of voiced regions are used as speaker dependent features. The second method presented uses features found in other works, but evaluated differently. A knock—out scheme is used to provide the weightage values for the selection of features. Results of implementation are presented which show on an average of 80% recognition. It is also shown that if there are long gaps between sessions, the performance deteriorates and is speaker dependent. Cross recognition percentages are also presented and this in the worst case rises to 30% while the best case is 0%. Suggestions for further work are given in the concluding chapter.

Geografia humana, recerca de suports audio-visuals : la ciutat. 'Geografía humana, búsqueda de soportes audio-visuales : la ciudad'.

Crear un material audio-visual. Mejorar la calidad de la enseñanza. Estudiar la aplicación de programas audio-visuales en el aula. Buscar una metodología adecuada a la utilización didáctica de los medios audio-visuales. Comprobar las diferencias que pueden existir entre diferentes medios audio-visuales, diapositivas-vídeo. La muestra está formada por los niños de tres aulas de segundo de BUP del Colegio Escoles Pies de Sarrià (Barcelona). En total 102 sujetos que han estudiado primero de BUP en el mismo centro. Se expone el marco teórico. Se describen las variables (medios audio-visuales, rendimiento escolar, rendimiento escolar anterior, metodología, inteligencia, clase social, profesor y edad). Se describe la muestra. División de la muestra en tres clases (sin medio audio-visual, con vídeo, con diapositivas). Realización del material audio-visual. Se realizan las sesiones pertinentes en cada clase. Aplicación de la prueba objetiva. Se analizan los datos. Se ofrecen conclusiones y alternativas. Prueba objetiva de rendimiento. Test d'aptituds diferencials. Baremo de puntuaciones anteriores. Diferencia de medias, estadística descriptiva, análisis de varianza, prueba de Scheffe, para establecer si hay diferencias entre el grupo que ha trabajado con medio audio-visual, visual y sin medio audiovisual. La metodología experimental aplicada no ha producido los resultados esperados, hay razones para afirmar que han intervenido factores no controlados, ajenos a la experimentación. Se constata un gran interés de los alumnos por el uso del vídeo como elemento de motivación. Se señala la importancia de incidir en este campo creando metodologías activas adecuadas y series de programas válidos. Hace falta una intensa investigación en las posibilidades y efectos de dichas metodologías.

Hemispheric asymmetries in recognition memory for negative and neutral words

Federmeier and Benjamin (2005) have suggested that semantic encoding for verbal information in the right hemisphere can be more effective when memory demands are higher. However, other studies (Kanske & Kotz, 2007) also suggest that visual word recognition differ in function of emotional valence. In this context, the present study was designed to evaluate the effects of retention level upon recognition memory processes for negative and neutral words. Sample consisted of 15 right-handed undergraduate portuguese students with normal or corrected to normal vision. Portuguese concrete negative and neutral words were selected in accordance to known linguistic capabilities of the right hemisphere. The participants were submitted to a visual half-field word presentation using a continuous recognition memory paradigm. Eye movements were continuously monitored with a Tobii T60 eye-tracker that showed no significant differences in fixations to negative and neutral words. Reaction times in word recognition suggest an overall advantage of negative words in comparison to the neutral words. Further analysis showed faster responses for negative words than for neutral words when were recognised at longer retention intervals for left-hemisphere encoding. Electrophysiological data through event related potentials revealed larger P2 amplitude over centro-posterior electrode sites for words studied in the left hemifield suggesting a priming effect for right-hemisphere encoding. Overall data suggest different hemispheric memory strategies for the semantic encoding of negative and neutral words.

Neural mechanisms of visual object priming: evidence for perceptual and semantic distinctions in fusiform cortex

Previous functional imaging studies have shown that facilitated processing of a visual object on repeated, relative to initial, presentation (i.e., repetition priming) is associated with reductions in neural activity in multiple regions, including fusiforin/lateral occipital cortex. Moreover, activity reductions have been found, at diminished levels, when a different exemplar of an object is presented on repetition. In one previous study, the magnitude of diminished priming across exemplars was greater in the right relative to the left fusiform, suggesting greater exemplar specificity in the right. Another previous study, however, observed fusiform lateralization modulated by object viewpoint, but not object exemplar. The present fMRI study sought to determine whether the result of differential fusiform responses for perceptually different exemplars could be replicated. Furthermore, the role of the left fusiform cortex in object recognition was investigated via the inclusion of a lexical/semantic manipulation. Right fusiform cortex showed a significantly greater effect of exemplar change than left fusiform, replicating the previous result of exemplar-specific fusiform lateralization. Right fusiform and lateral occipital cortex were not differentially engaged by the lexical/semantic manipulation, suggesting that their role in visual object recognition is predominantly in the. C visual discrimination of specific objects. Activation in left fusiform cortex, but not left lateral occipital cortex, was modulated by both exemplar change and lexical/semantic manipulation, with further analysis suggesting a posterior-to-anterior progression between regions involved in processing visuoperceptual and lexical/semantic information about objects. The results are consistent with the view that the right fusiform plays a greater role in processing specific visual form information about objects, whereas the left fusiform is also involved in lexical/semantic processing. (C) 2003 Elsevier Science (USA). All rights reserved.

Filmljudets funktioner i krigsfilm : En audio-visuell analys av Apocalypse Now och Saving Private Ryan

I denna uppsats har filmljudet i krigsfilmerna Apocalypse Now och Saving Private Ryan undersökts. Detta har gjorts för att försöka bidra med ökad förståelse för filmljudets användningsområde och funktioner, främst för filmerna i fråga, men även för krigsfilm rent generellt. Filmljud i denna kontext omfattar allt det ljud som finns i film, men utesluter dock all ickediegetisk musik. Båda filmerna har undersökts genom en audio-visuell analys. En sådan analys görs genom att detaljgranska båda filmernas ljud- och bildinnehåll var för sig, för att slutligen undersöka samma filmsekvens som helhet då ljudet och bilden satts ihop igen. Den audio-visuella analysmetod som nyttjats i uppsatsen är Michel Chions metod, Masking. De 30 minuter film som analyserades placerades sedan i olika filmljudzoner, där respektive filmljudzons ljudinnehåll bland annat visade vilka främsta huvudfunktioner somfilmljudet hade i dessa filmer. Dessa funktioner är till för att bibehålla åskådarens fokus och intresse, att skapa närhet till rollkaraktärerna, samt att tillföra en hög känsla av realism och närvaro. Intentionerna med filmljudet verkade vara att flytta åskådaren in i filmens verklighet, att låta åskådaren bli ett med filmen. Att återspegla denna känsla av realism, närvaro, fokus samt intresse, visade sig också vara de intentioner som funnits redan i de båda filmernas förproduktionsstadier. Detta bevisar att de lyckats åstadkomma det de eftersträvat. Men om filmljudet använts på samma sätt eller innehar samma funktioner i krigsfilm rent genrellt går inte att säga.I have for this bachelor’s thesis examined the movie sound of the classic warfare movies Apocalypse Now and Saving Private Ryan. This is an attempt to contribute to a more profound comprehension of the appliance and importance of movie sound. In this context movie sound implies all kinds of sounds within the movies, accept from non-diegetic music. These two movies have been examined by an audio-visual analysis. It's done by auditing the sound and picture content separately, and then combined to audit the same sequence as a whole. Michel Chion, which is the founder of this analysis, calls this method Masking. The sound in this 30 minute sequence was then divided into different zones, where every zone represented a certain main function. These functions are provided to create a stronger connection to the characters, sustain the viewers interest and bring a sense of realism and presence. It seems though the intention with the movies sound is to bring the viewers to the scene in hand, and let it become their reality. To mirror this sense of realism, presence, focus and interest, proves to be the intention from an early stage of the production. This bachelor’s thesis demonstrates a success in their endeavours. Although it can’t confirm whether the movie sound have been utilized in the same manner or if they posess the same functions to warefare movies in general.

Variável colativa por complexidade, seus efeitos no campo visual monocular

Os resultados das análises feitas com estes dados indicaram diferenças significativas no aumento da amplitude do plano meridiano horizontal nasal do campo visual monocular, medidas em unidades angulares. As diferenças foram interpretadas como indicativas da influência dos três diferentes níveis de complexidade dos estímulos visuais. Concluiu-se, portanto, que a variável colativa por complexidade influi no ato perceptual do reconhecimento visual.

A comunicação como barreira à inclusão de alunos com deficiência visual em aulas de óptica

O presente artigo representa uma continuidade dos resultados apresentados em Camargo e Nardi (Revista Brasileira de Ensino de Física 29, 117 (2007)). Encontra-se inserido dentro de um estudo que busca compreender as principais barreiras para a inclusão de alunos com deficiência visual no contexto do ensino de física. Focalizando aulas de óptica, analisa as dificuldades comunicacionais entre licenciandos e discentes com deficiência visual. Para tal, enfatiza as estruturas empírica e semântico-sensorial das linguagens utilizadas, indicando fatores geradores de dificuldades de acessibilidade nas informações veiculadas. Recomenda, ainda, alternativas que visam dar condições à participação efetiva do discente com deficiência visual no processo comunicativo, das quais destacam-se: a identificação da estrutura semântico-sensorial dos significados veiculados, o conhecimento da história visual do aluno, a destituição da estrutura empírica audiovisual interdependente e a exploração das potencialidades comunicacionais das linguagens constituídas de estruturas empíricas de acesso visualmente independente. Conclui afirmando que a comunicação representa a principal barreira à participação efetiva de alunos com deficiência visual em aulas de óptica e enfatiza a importância da criação de canais comunicacionais adequados como condição básica à inclusão desses alunos.

Eficácia do programa de remediação auditivo-visual computadorizado em escolares com dislexia

TEMA: programa de remediação auditivo-visual computadorizado em escolares com dislexia do desenvolvimento. OBJETIVOS: verificar a eficácia de um programa de remediação auditivo-visual computadorizado em escolares com dislexia do desenvolvimento. Dentre os objetivos específicos, o estudo teve como finalidade comparar o desempenho cognitivo-lingüístico de escolares com dislexia do desenvolvimento com escolares bons leitores; comparar os achados dos procedimentos de avaliação de pré e pós testagem em escolares com dislexia submetidos e não submetidos ao programa; e, por fim, comparar os achados do programa de remediação em escolares com dislexia e escolares bons leitores submetidos ao programa de remediação. MÉTODO: participaram deste estudo 20 escolares, sendo o grupo I (GI) subdivido em: GIe, composto de cinco escolares com dislexia do desenvolvimento submetidos ao programa, e GIc, composto de cinco escolares com dislexia do desenvolvimento não submetidos ao programa. O grupo II (GII) foi subdividido em GIIe, composto de cinco escolares bons leitores submetidos à remediação, e GIIc, composto de cinco escolares bons leitores não submetidos à remediação. Foi realizado o programa de remediação auditivo-visual computadorizado Play-on. RESULTADOS: os resultados deste estudo revelaram que o GI apresentou desempenho inferior em habilidade de processamento auditivo e de consciência fonológica em comparação com o GII em situação de pré-testagem. Entretanto, o GIe apresentou desempenho semelhante ao GII em situação de pós-testagem, evidenciando a eficácia da remediação auditivo-visual em escolares com dislexia do desenvolvimento. CONCLUSÃO: o estudo evidenciou a eficácia do programa de remediação auditivo-visual em escolares com dislexia do desenvolvimento.

Hybrid visual-driven decision support system in video monitor manufacturing

An intelligent system that emulates human decision behaviour based on visual data acquisition is proposed. The approach is useful in applications where images are used to supply information to specialists who will choose suitable actions. An artificial neural classifier aids a fuzzy decision support system to deal with uncertainty and imprecision present in available information. Advantages of both techniques are exploited complementarily. As an example, this method was applied in automatic focus checking and adjustment in video monitor manufacturing. Copyright © 2005 IFAC.

Proposta teórico-metodológica para análise de inserções parentéticas em chat educacional no ensino de língua espanhola =: Propuesta teórico-metodológica para el análisis de inserciones parentéticas en chat educacional en la enseñanza de lengua española

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Contextos comunicacionais adequados e inadequados à inclusão de alunos com deficiência visual em aulas de mecânica

This article is inserted in a study aimed at the identification of the main barriers for the inclusion of visually-impaired students in Physics classes. It focuses on the understanding of the communication context which facilitates or hardens the effective participation of students with visual impairment in Mechanics activities. To do so, the research defines, from empirical - sensory and semantic structures, the language to be applied in the activities, as well as, the moment and the speech pattern in which the languages have been used. As a result, it identifies the rela tion between the uses of the interdependent audio-visual empirical lan guage structure in the non-interactive episodes of authority; the decrease in the use of this structure in interactive episodes; the creation of educa tional segregation environments within the classroom and the frequent use of the interdependent tactile-hearing empirical language structure in such environments.

Contextos comunicacionais adequados e inadequados à inclusão de alunos com deficiência visual em aulas de termologia

This article represents a continuation of the results of a research presented in Camargo and Nardi (2007). It is inserted in the study that seeks to understand the main student’s inclusion barriers with visual impairment in the Physics classes. It aims to understand which communication context shows kindness or unkindness to the impairment visual student’s real participation in thermology activities. For this, the research defines, from the empirical - sensory and semantics structures, the used languages in the activities, as well, the moment and the speech pattern in which the languages have been used. As result, identifies a strong relation between the uses of the interdependent empirical structure audio-visual language in the non-interactive episodes of authority; a decrease of this structure use in the interactive episodes and the creation of education segregation environments within the classroom.

Contextos comunicacionales adecuados e inadecuados para la inclusión de alumnos con discapacidad visual en clases de física moderna

This article is inserted in a wider study that seeks to understand the main inclusion barriers in Physics classes for students with visual impairment It aims to understand which communication context favors or impedes the visually impaired student participation to the impairment visual student’s real participation in Modern Physics activities. The research defines, from the empirical-sensory and semantics structures, the languages used in the activities, as well as, the moment and the speech pattern in which those languages have been used. As a result, this study identifies a strong relation between the uses of the interdependent empirical structure audio-visual language in the non-interactive episodes of authority; a decrease of this structure use in the interactive episodes; the creation of education segregation environments within the clasroom and the frequent use of empirical tactile-hearing interdependent language structure in these environments. Moreover, the concept of «special educational need» is discussed and its inadequate use is analyzed. Suggestions are given for its correct use of «special educational need,» its inadequate use, giving suggestions for its correct use.

Ensino de Física para alunos com deficiência visual: o processo de ensino-aprendizagem nos ambientes escolares das salas de aula regular e de recursos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)