Submitted by Verônica Esteves (vevenesteves@gmail.com) on 2017-09-22T12:07:34Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Caracterização histomorfométrica e esteriológica das fibras ... (dissertação - Filipe Moreira de Andrade).pdf: 755223 bytes, checksum: fd1e41efdcbec772c4c1b66378c0acbf (MD5) / Approved for entry into archive by Verônica Esteves (vevenesteves@gmail.com) on 2017-09-22T12:08:14Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Caracterização histomorfométrica e esteriológica das fibras ... (dissertação - Filipe Moreira de Andrade).pdf: 755223 bytes, checksum: fd1e41efdcbec772c4c1b66378c0acbf (MD5) / Made available in DSpace on 2017-09-22T12:08:14Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Caracterização histomorfométrica e esteriológica das fibras ... (dissertação - Filipe Moreira de Andrade).pdf: 755223 bytes, checksum: fd1e41efdcbec772c4c1b66378c0acbf (MD5) Previous issue date: 2010 / Universidade Federal de Viçosa. Departamento de Medicina e Enfermagem / A matriz extracelular é elemento essencial à função peniana, podendo ser acometida por doenças locais ou sistêmicas, embora pouco seja conhecido em relação aos seus componentes na glande peniana humana. Nesse trabalho foi realizado um estudo detalhado da organização morfológica e densidade volumétrica (Vv) das fibras do sistema elástico em glandes penianas de homens jovens saudáveis. Foram obtidos fragmentos de glande peniana de 5 (cinco) indivíduos jovens falecidos de causas não relacionadas ao sistema urogenital, com idade entre 18 e 30 anos (média: 24 anos). Os espécimes foram fixados em formalina, embebidos em parafina e processados histologicamente. As fibras do sistema elástico foram avaliadas sob microscopia óptica usando a técnica de coloração da resorcina-fucsina de Weigert após prévia oxidação pela oxona. Estudos morfométricos foram realizados através do método de contagem de pontos. A análise quantitativa foi expressa (% média) como densidade volumétrica (Vv) através da análise em 25 campos aleatórios para cada espécime. Verificou-se que os constituintes do tecido conjuntivo, em especial fibras do sistema elástico, foram abundantes. Uma rede irregular de fibras do sistema elástico é distribuída sob a mucosa da glande peniana. As fibras do sistema elástico apresentaram uma disposição longitudinal no corpo esponjoso e um perfil tortuoso envolvendo sinúsóides da glande. A Vv das fibras do sistema elástico na glande peniana é de 29.4% ±3.1. Os dados devem prover informação a ser avaliada em relação a disfunções eréteis, doenças endócrinas e envelhecimento. Os resultados apresentados fornecem subsídios para posteriores investigações em relação à matriz extracelular por métodos de estereologia / The extracellular matrix is a key element in penile function and pathology, yet little is known of its components in human glans. Herein we carried out a detailed study of all the factors that play a part in the morphological organization and volumetric density (Vv) of elastic fibers in the glans penis of young healthy men. Penile glans were obtained from 5 young men died of causes no related to the urogenital tract, between the age of 18 and 30 (mean = 24). Samples were fixed in formaline, embedded in paraffin, and histologically processed. The elastic system fibers were evaluated at light microscopy by using Weigert’s resorcin-fuchsin technique after previous oxidation with oxone. Morphometric studies were performed by the point-counting method. Quantities were expressed (%mean) as volumetric densities (Vv) and were determined on 25 random fields for each individual. Connective tissue elements, mainly elastic system fibers, were abundant. These fibers often had a tortuous profile and surrounded sinusoids in the glans penis. An irregular elastic fibers network was distributed beneath the glans penis mucosa, on the other hand, underneath the mucosa, the elastic fibers were observed longitudinal at corpus spongiosum. The Vv of the elastic system fibers in the glans penis is 29.4% ±3.1. The data should therefore provide important information for drawing parallels over patients with erectile dysfunction and alterations regarding endocrine diseases and aging. The results reported herein provide the base for continuous investigations on extracellular matrix by stereology

This dissertation presents new modular and integrative information methods and systems inspired by the way the brain performs information processing, in particular, pattern recognition. The proposed artificial systems use spiking neurons as basic elements, which are the key components of spiking neural networks. Of particular interest to this research are various spiking neural network architectures and learning procedures that permit different pattern recognition problems to be solved in an evolvable and adaptive way. Spiking neural networks are used to model human visual and auditory pathways and are trained to perform the specific task of person authentication. The systems are individually tuned and trained to recognize facial information and to analyze sound signals from spoken sentences. The modelling of the integration of different sources of information (multisensory integration) using spiking neural networks is also a subject of investigation. A network architecture is proposed and a model for audiovisual pattern recognition is designed as an example. The main original contributions of this thesis are: a) Evaluation and further extension of adaptive learning procedures to perform visual pattern recognition. A new learning procedure that enables the system to change its structure, creating/merging neuronal maps of spiking neurons is presented and evaluated on a face recognition problem. b) Design of two new spiking neural network architectures to perform person authentication through the processing of speech signals. c) Design and evaluation of a new architecture that integrates sensory modalities based on spiking neurons. The integrative architecture combines opinions from individual modalities within a supramodal layer, which contains neurons sensitive to multiple sensory information. An additional feature that increases biological relevance is the crossmodal coupling of modalities, which effectively enables a given sensory modality to exert direct influence upon the processing areas typically related to other modalities. The contributions were published in one journal paper and in four refereed international conference proceedings. The proposed system designs were implemented and, through computer simulations, demonstrated comparable performance with traditional benchmarking methods. The systems have some promising features: they can be naturally optimized in respect to different criteria: accuracy (when very accurate results are expected), energy efficiency (when management of resources play an important role), and speed (when a decision needs to be made within a limited time). In this thesis, most of the parameters have been exhaustively optimized by hand or by using simple heuristics. As a direction for future work, there is an opportunity to include automated, specially tailored parameters optimization procedures or even general-purpose optimization algorithms, e.g., Genetic Algorithms and Particle Swarm Optimization. Overall, the results obtained in this thesis clearly indicate that it is indeed possible to have fast and accurate adaptive pattern recognition systems scalable for multiple modalities computing with simple models of spiking neurons. However, it is important to advance the theory of spiking neurons to take advantage of its biological relevance to reach similar or better performance when compared to the human brain, for instance, exploring new neuron models, information coding schemes and network connectivity.

ABSTRACT An Explorative Analysis Evaluation of Electronic Retailing Customer Adoptions In the Context of Saudi Arabia To learn more about what people in Saudi Arabia thought about online shopping, a survey was distributed throughout public locations in three major cities: Riyadh, Jeddah, and Medina. The questionnaires investigated consumers’ intersecting views regarding online and in-store shopping, and attempted to learn more about the perceived usefulness and attractiveness of online shopping in Saudi Arabia, as well as privacy or trust issues related to online shopping that are relevant for Saudi customer. The main findings of this study revealed several important tendencies. For one, the study found that males favoured shopping online more than females. Moreover, respondents appeared to find online shopping to be relaxing due to reduced sales pressure. Also, proficiency in the English language seemed to be a determining factor in the consumer’s preference to shop online. In addition, people who seemed to dislike physical shopping favoured the idea of e-shopping. The findings above are exploratory in nature due to the limited sample size and sampling process. Additional study with expanded sample across a broader Saudi Arabian geographic base could be used to confirm the use initial exploratory findings.

This dissertation presents new modular and integrative information methods and systems inspired by the way the brain performs information processing, in particular, pattern recognition. The proposed artificial systems use spiking neurons as basic elements, which are the key components of spiking neural networks. Of particular interest to this research are various spiking neural network architectures and learning procedures that permit different pattern recognition problems to be solved in an evolvable and adaptive way. Spiking neural networks are used to model human visual and auditory pathways and are trained to perform the specific task of person authentication. The systems are individually tuned and trained to recognize facial information and to analyze sound signals from spoken sentences. The modelling of the integration of different sources of information (multisensory integration) using spiking neural networks is also a subject of investigation. A network architecture is proposed and a model for audiovisual pattern recognition is designed as an example. The main original contributions of this thesis are: a) Evaluation and further extension of adaptive learning procedures to perform visual pattern recognition. A new learning procedure that enables the system to change its structure, creating/merging neuronal maps of spiking neurons is presented and evaluated on a face recognition problem. b) Design of two new spiking neural network architectures to perform person authentication through the processing of speech signals. c) Design and evaluation of a new architecture that integrates sensory modalities based on spiking neurons. The integrative architecture combines opinions from individual modalities within a supramodal layer, which contains neurons sensitive to multiple sensory information. An additional feature that increases biological relevance is the crossmodal coupling of modalities, which effectively enables a given sensory modality to exert direct influence upon the processing areas typically related to other modalities. The contributions were published in one journal paper and in four refereed international conference proceedings. The proposed system designs were implemented and, through computer simulations, demonstrated comparable performance with traditional benchmarking methods. The systems have some promising features: they can be naturally optimized in respect to different criteria: accuracy (when very accurate results are expected), energy efficiency (when management of resources play an important role), and speed (when a decision needs to be made within a limited time). In this thesis, most of the parameters have been exhaustively optimized by hand or by using simple heuristics. As a direction for future work, there is an opportunity to include automated, specially tailored parameters optimization procedures or even general-purpose optimization algorithms, e.g., Genetic Algorithms and Particle Swarm Optimization. Overall, the results obtained in this thesis clearly indicate that it is indeed possible to have fast and accurate adaptive pattern recognition systems scalable for multiple modalities computing with simple models of spiking neurons. However, it is important to advance the theory of spiking neurons to take advantage of its biological relevance to reach similar or better performance when compared to the human brain, for instance, exploring new neuron models, information coding schemes and network connectivity.

Operations capabilities provide the fundamental basis of competitive advantage for manufacturing firms. Thus, it is crucial for managers as well as researchers to understand the importance of operations capabilities within the respective market environment. This thesis evaluates the most important operations capability dimensions as well as operations capabilities for competitive manufacturing in a high-cost environment and how they differ based on manufacturing firm characteristics. Therefore, a quantitative survey was conducted within the high-cost environments Sweden and Germany. Empirical findings show that quality is the order-winning criterion in high-cost environments, followed by delivery, cost and flexibility. However, the importance highly differs across the various manufacturing firm characteristics. Managers of manufacturing firms in high-cost environments can use these findings to validate and adjust their operations strategy to achieve a competitive advantage.

ABSTRACT An Explorative Analysis Evaluation of Electronic Retailing Customer Adoptions In the Context of Saudi Arabia To learn more about what people in Saudi Arabia thought about online shopping, a survey was distributed throughout public locations in three major cities: Riyadh, Jeddah, and Medina. The questionnaires investigated consumers’ intersecting views regarding online and in-store shopping, and attempted to learn more about the perceived usefulness and attractiveness of online shopping in Saudi Arabia, as well as privacy or trust issues related to online shopping that are relevant for Saudi customer. The main findings of this study revealed several important tendencies. For one, the study found that males favoured shopping online more than females. Moreover, respondents appeared to find online shopping to be relaxing due to reduced sales pressure. Also, proficiency in the English language seemed to be a determining factor in the consumer’s preference to shop online. In addition, people who seemed to dislike physical shopping favoured the idea of e-shopping. The findings above are exploratory in nature due to the limited sample size and sampling process. Additional study with expanded sample across a broader Saudi Arabian geographic base could be used to confirm the use initial exploratory findings.

Submitted by Ana Lúcia Torres (bfmhuap@gmail.com) on 2017-09-25T19:01:03Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Caracterização histomorfométrica e esteriológica das fibras ... (dissertação - Filipe Moreira de Andrade).pdf: 755223 bytes, checksum: fd1e41efdcbec772c4c1b66378c0acbf (MD5) / Approved for entry into archive by Ana Lúcia Torres (bfmhuap@gmail.com) on 2017-09-25T19:01:21Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Caracterização histomorfométrica e esteriológica das fibras ... (dissertação - Filipe Moreira de Andrade).pdf: 755223 bytes, checksum: fd1e41efdcbec772c4c1b66378c0acbf (MD5) / Made available in DSpace on 2017-09-25T19:01:21Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Caracterização histomorfométrica e esteriológica das fibras ... (dissertação - Filipe Moreira de Andrade).pdf: 755223 bytes, checksum: fd1e41efdcbec772c4c1b66378c0acbf (MD5) Previous issue date: 2010 / Universidade Federal de Viçosa. Departamento de Medicina e Enfermagem / A matriz extracelular é elemento essencial à função peniana, podendo ser acometida por doenças locais ou sistêmicas, embora pouco seja conhecido em relação aos seus componentes na glande peniana humana. Nesse trabalho foi realizado um estudo detalhado da organização morfológica e densidade volumétrica (Vv) das fibras do sistema elástico em glandes penianas de homens jovens saudáveis. Foram obtidos fragmentos de glande peniana de 5 (cinco) indivíduos jovens falecidos de causas não relacionadas ao sistema urogenital, com idade entre 18 e 30 anos (média: 24 anos). Os espécimes foram fixados em formalina, embebidos em parafina e processados histologicamente. As fibras do sistema elástico foram avaliadas sob microscopia óptica usando a técnica de coloração da resorcina-fucsina de Weigert após prévia oxidação pela oxona. Estudos morfométricos foram realizados através do método de contagem de pontos. A análise quantitativa foi expressa (% média) como densidade volumétrica (Vv) através da análise em 25 campos aleatórios para cada espécime. Verificou-se que os constituintes do tecido conjuntivo, em especial fibras do sistema elástico, foram abundantes. Uma rede irregular de fibras do sistema elástico é distribuída sob a mucosa da glande peniana. As fibras do sistema elástico apresentaram uma disposição longitudinal no corpo esponjoso e um perfil tortuoso envolvendo sinúsóides da glande. A Vv das fibras do sistema elástico na glande peniana é de 29.4% ±3.1. Os dados devem prover informação a ser avaliada em relação a disfunções eréteis, doenças endócrinas e envelhecimento. Os resultados apresentados fornecem subsídios para posteriores investigações em relação à matriz extracelular por métodos de estereologia / The extracellular matrix is a key element in penile function and pathology, yet little is known of its components in human glans. Herein we carried out a detailed study of all the factors that play a part in the morphological organization and volumetric density (Vv) of elastic fibers in the glans penis of young healthy men. Penile glans were obtained from 5 young men died of causes no related to the urogenital tract, between the age of 18 and 30 (mean = 24). Samples were fixed in formaline, embedded in paraffin, and histologically processed. The elastic system fibers were evaluated at light microscopy by using Weigert’s resorcin-fuchsin technique after previous oxidation with oxone. Morphometric studies were performed by the point-counting method. Quantities were expressed (%mean) as volumetric densities (Vv) and were determined on 25 random fields for each individual. Connective tissue elements, mainly elastic system fibers, were abundant. These fibers often had a tortuous profile and surrounded sinusoids in the glans penis. An irregular elastic fibers network was distributed beneath the glans penis mucosa, on the other hand, underneath the mucosa, the elastic fibers were observed longitudinal at corpus spongiosum. The Vv of the elastic system fibers in the glans penis is 29.4% ±3.1. The data should therefore provide important information for drawing parallels over patients with erectile dysfunction and alterations regarding endocrine diseases and aging. The results reported herein provide the base for continuous investigations on extracellular matrix by stereology

O ato de investir recursos vem se tornando uma tarefa que exige cada vez mais atenção por parte dos investidores. As alternativas de investimento vêm aumentando, oferecendo aos investidores muitas opções em termos de risco, retorno e liquidez. Uma dessas alternativas é o fundo de investimento, uma indústria cujo patrimônio tem crescido muito ao longo do tempo. Atualmente, há mais de R$ 200 bilhões aplicados nas diversas modalidades de fundos oferecidos pelas instituições administradoras de recursos. Escolher qual fundo investir não é tarefa simples, nem mesmo para grandes investidores. As alternativas são inúmeras e as informações nem sempre estão facilmente disponíveis. Oferecer um método que possibilite avaliar e classificar fundos de investimento é o objetivo maior deste trabalho. Busca-se, aqui, um método que contemple, além de variáveis quantitativas, variáveis qualitativas, bem como aspectos relacionados à instituição administradora do fundo. Para alcançar tal objetivo, desenvolveu-se a pesquisa em duas etapas. Na primeira, foram levantadas e agrupadas, através de pesquisa bibliográfica, as variáveis que poderiam vir a fazer parte do método. A segunda etapa foi dedicada à obtenção da ponderação que cada variável e grupo de variável deveria ter no método. Para tanto, foi realizada uma pesquisa de campo junto a determinados grupos de investidores e consultores. O resultado permite que um avaliador dê notas às variáveis e, seguindo o método, obtenha uma nota final para o fundo de investimento analisado. Por fim, sugere-se um modo de classificação de fundos de investimento que procura ser de fácil entendimento, mesmo para aqueles investidores que não são especialistas em mercado financeiro. / Investing money has becoming a task that demands always more attention by investors. Investment alternatives has been growing, offering investors many options in terms of risk, return and liquidity. One of these alternatives is mutual fund, an industry whose assets have been growing a lot during the last years. Nowadays, there are more than R$ 200 billions invested in mutual funds, offered by asset managers. Choosing a fund to invest is not a simple task, even for main investors. There are many alternatives and information is not easily available. Offering a method that permits evaluate and rate mutual funds is the main purpose of this research. This method includes quantitative and qualitative variables, as well as aspects related to its asset manager. To attain this objective, this research was developed in two steps. Firstly, it was selected variables that could be part of the method, by bibliographic search. Secondly, it was obtained weights for both the variables and their group. This goal was achieved through a questionnaire sent to specific investors and consultants. The final result permits an analyst to give a grade to each variable and, using the method, to obtain a final classification for the analyzed fund. This dissertation suggests also a method for ranking mutual funds which intents to be easily comprehended, even to those investors that are not specialized in investment market.

A percepção de presença (PP), evolução do conceito de telepresença, pode ser definida como ilusão perceptiva de não mediação e/ou a percepção ilusória da realidade. O método mais utilizado para a avaliação da PP faz uso de questionários aplicados aos sujeitos, após sua participação numa experiência. Além de não fornecer informações em tempo real esse método sofre muitas interferências advindas tanto dos sujeitos submetidos ao experimento como dos avaliadores dos questionários. Os métodos que poderiam ser mais efetivos para a avaliação da PP, em tempo real, fazem uso de sinais fisiológicos que variam independentemente da vontade dos sujeitos, como batimento cardíaco, eletrocardiograma, eletroencefalograma, resistividade e umidade da pele. Os sinais fisiológicos, no entanto, só variam de forma significativa em situações de estresse, inviabilizando sua utilização em atividades normais, sem estresse. Outra forma de avaliar a PP é utilizar sistemas de rastreamento do olhar. Estudados e desenvolvidos desde o século 19, os sistemas de rastreamento do olhar fornecem um mapeamento do movimento dos olhos. Além de indicar para onde os sujeitos estão olhando, podem também monitorar a dilatação da pupila e as piscadas. Atualmente existem sistemas de rastreamento do olhar comerciais de baixo custo, que apesar de terem menos precisão e frequência que os equipamentos de alto custo são mais práticos e possuem software de plataforma aberta. No futuro serão tão comuns e simples de usar como são hoje as câmeras em dispositivos móveis e computadores, o que viabilizará a aplicação das técnicas e métodos aqui propostos em larga escala, principalmente para monitorar a atenção e envolvimento de atividades mediadas por vídeo. É apresentada uma ferramenta que faz uso do rastreamento do olhar para avaliar a percepção de presença em atividades mediadas por vídeo (com estímulos sonoros). Dois experimentos foram realizados para validar as hipóteses da pesquisa e a ferramenta. Um terceiro experimento foi executado para verificar a capacidade da ferramenta em avaliar a percepção de presença em atividades não estressantes mediadas por vídeo. / The presence perception (PP), evolution of the concept of telepresence, could be defined as the perceptual illusion of nonmediation and/or the ilusional perception of reality. The most utilized method for PP evaluation make uses questionnaires applied for the subjects, after your participation in an experience. Besides it does not provide real-time information this method suffers with many interferences in the results that come from the subjects undergoing and form the reviewers of the of the questionnaires. The methods could be more effective for PP evaluation, in real time, make uses of physiologic signals that vary independently of the request of the subjects, e.g. heart rate, electrocardiogram, electroencephalogram, skin resistivity and skin humidity. However, meaningful physiologic signals occurs only in stress situations, unfeasible Its use in normal environments, whit no stress. Another way to evaluate the PP is using eye gaze tracking systems. Studied and developed since the 19th century, eye gaze tracking systems provide an eye movements mapping. Moreover it indicate where the subjects are viewing, these systems can follow up pupil dilatation and blinks. Currently there are commercial gaze tracking systems inexpensive, despite having less precision and frequency that expensive-equipments are more practical and open software platform is available. In the future these technologies will be common and simple to use as today are cameras on mobile devices and computers, which will enable the implementation of the techniques and methods here proposed on a large scale, mainly to monitor the attention and involvement during activities mediated by video. A tool that makes use of gaze tracking to evaluate presence perception in activities video mediated (with sound stimuli) is displayed. Two experiments were conducted to validate the hypotheses of the research and the tool. A third experiment was performed to verify the tool\'s ability to assess presence perception in non-stressful activities video mediated.

A percepção de presença (PP), evolução do conceito de telepresença, pode ser definida como ilusão perceptiva de não mediação e/ou a percepção ilusória da realidade. O método mais utilizado para a avaliação da PP faz uso de questionários aplicados aos sujeitos, após sua participação numa experiência. Além de não fornecer informações em tempo real esse método sofre muitas interferências advindas tanto dos sujeitos submetidos ao experimento como dos avaliadores dos questionários. Os métodos que poderiam ser mais efetivos para a avaliação da PP, em tempo real, fazem uso de sinais fisiológicos que variam independentemente da vontade dos sujeitos, como batimento cardíaco, eletrocardiograma, eletroencefalograma, resistividade e umidade da pele. Os sinais fisiológicos, no entanto, só variam de forma significativa em situações de estresse, inviabilizando sua utilização em atividades normais, sem estresse. Outra forma de avaliar a PP é utilizar sistemas de rastreamento do olhar. Estudados e desenvolvidos desde o século 19, os sistemas de rastreamento do olhar fornecem um mapeamento do movimento dos olhos. Além de indicar para onde os sujeitos estão olhando, podem também monitorar a dilatação da pupila e as piscadas. Atualmente existem sistemas de rastreamento do olhar comerciais de baixo custo, que apesar de terem menos precisão e frequência que os equipamentos de alto custo são mais práticos e possuem software de plataforma aberta. No futuro serão tão comuns e simples de usar como são hoje as câmeras em dispositivos móveis e computadores, o que viabilizará a aplicação das técnicas e métodos aqui propostos em larga escala, principalmente para monitorar a atenção e envolvimento de atividades mediadas por vídeo. É apresentada uma ferramenta que faz uso do rastreamento do olhar para avaliar a percepção de presença em atividades mediadas por vídeo (com estímulos sonoros). Dois experimentos foram realizados para validar as hipóteses da pesquisa e a ferramenta. Um terceiro experimento foi executado para verificar a capacidade da ferramenta em avaliar a percepção de presença em atividades não estressantes mediadas por vídeo. / The presence perception (PP), evolution of the concept of telepresence, could be defined as the perceptual illusion of nonmediation and/or the ilusional perception of reality. The most utilized method for PP evaluation make uses questionnaires applied for the subjects, after your participation in an experience. Besides it does not provide real-time information this method suffers with many interferences in the results that come from the subjects undergoing and form the reviewers of the of the questionnaires. The methods could be more effective for PP evaluation, in real time, make uses of physiologic signals that vary independently of the request of the subjects, e.g. heart rate, electrocardiogram, electroencephalogram, skin resistivity and skin humidity. However, meaningful physiologic signals occurs only in stress situations, unfeasible Its use in normal environments, whit no stress. Another way to evaluate the PP is using eye gaze tracking systems. Studied and developed since the 19th century, eye gaze tracking systems provide an eye movements mapping. Moreover it indicate where the subjects are viewing, these systems can follow up pupil dilatation and blinks. Currently there are commercial gaze tracking systems inexpensive, despite having less precision and frequency that expensive-equipments are more practical and open software platform is available. In the future these technologies will be common and simple to use as today are cameras on mobile devices and computers, which will enable the implementation of the techniques and methods here proposed on a large scale, mainly to monitor the attention and involvement during activities mediated by video. A tool that makes use of gaze tracking to evaluate presence perception in activities video mediated (with sound stimuli) is displayed. Two experiments were conducted to validate the hypotheses of the research and the tool. A third experiment was performed to verify the tool\'s ability to assess presence perception in non-stressful activities video mediated.