13,877 research outputs found

    Computer-based tracking, analysis, and visualization of linguistically significant nonmanual events in American Sign Language (ASL)

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    Our linguistically annotated American Sign Language (ASL) corpora have formed a basis for research to automate detection by computer of essential linguistic information conveyed through facial expressions and head movements. We have tracked head position and facial deformations, and used computational learning to discern specific grammatical markings. Our ability to detect, identify, and temporally localize the occurrence of such markings in ASL videos has recently been improved by incorporation of (1) new techniques for deformable model-based 3D tracking of head position and facial expressions, which provide significantly better tracking accuracy and recover quickly from temporary loss of track due to occlusion; and (2) a computational learning approach incorporating 2-level Conditional Random Fields (CRFs), suited to the multi-scale spatio-temporal characteristics of the data, which analyses not only low-level appearance characteristics, but also the patterns that enable identification of significant gestural components, such as periodic head movements and raised or lowered eyebrows. Here we summarize our linguistically motivated computational approach and the results for detection and recognition of nonmanual grammatical markings; demonstrate our data visualizations, and discuss the relevance for linguistic research; and describe work underway to enable such visualizations to be produced over large corpora and shared publicly on the Web

    Time-Efficient Hybrid Approach for Facial Expression Recognition

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    Facial expression recognition is an emerging research area for improving human and computer interaction. This research plays a significant role in the field of social communication, commercial enterprise, law enforcement, and other computer interactions. In this paper, we propose a time-efficient hybrid design for facial expression recognition, combining image pre-processing steps and different Convolutional Neural Network (CNN) structures providing better accuracy and greatly improved training time. We are predicting seven basic emotions of human faces: sadness, happiness, disgust, anger, fear, surprise and neutral. The model performs well regarding challenging facial expression recognition where the emotion expressed could be one of several due to their quite similar facial characteristics such as anger, disgust, and sadness. The experiment to test the model was conducted across multiple databases and different facial orientations, and to the best of our knowledge, the model provided an accuracy of about 89.58% for KDEF dataset, 100% accuracy for JAFFE dataset and 71.975% accuracy for combined (KDEF + JAFFE + SFEW) dataset across these different scenarios. Performance evaluation was done by cross-validation techniques to avoid bias towards a specific set of images from a database

    Automatic Detection of Pain from Spontaneous Facial Expressions

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    This paper presents a new approach for detecting pain in sequences of spontaneous facial expressions. The motivation for this work is to accompany mobile-based self-management of chronic pain as a virtual sensor for tracking patients' expressions in real-world settings. Operating under such constraints requires a resource efficient approach for processing non-posed facial expressions from unprocessed temporal data. In this work, the facial action units of pain are modeled as sets of distances among related facial landmarks. Using standardized measurements of pain versus no-pain that are specific to each user, changes in the extracted features in relation to pain are detected. The activated features in each frame are combined using an adapted form of the Prkachin and Solomon Pain Intensity scale (PSPI) to detect the presence of pain per frame. Painful features must be activated in N consequent frames (time window) to indicate the presence of pain in a session. The discussed method was tested on 171 video sessions for 19 subjects from the McMaster painful dataset for spontaneous facial expressions. The results show higher precision than coverage in detecting sequences of pain. Our algorithm achieves 94% precision (F-score=0.82) against human observed labels, 74% precision (F-score=0.62) against automatically generated pain intensities and 100% precision (F-score=0.67) against self-reported pain intensities

    What does touch tell us about emotions in touchscreen-based gameplay?

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    This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2012 ACM. It is posted here by permission of ACM for your personal use. Not for redistribution.Nowadays, more and more people play games on touch-screen mobile phones. This phenomenon raises a very interesting question: does touch behaviour reflect the player’s emotional state? If possible, this would not only be a valuable evaluation indicator for game designers, but also for real-time personalization of the game experience. Psychology studies on acted touch behaviour show the existence of discriminative affective profiles. In this paper, finger-stroke features during gameplay on an iPod were extracted and their discriminative power analysed. Based on touch-behaviour, machine learning algorithms were used to build systems for automatically discriminating between four emotional states (Excited, Relaxed, Frustrated, Bored), two levels of arousal and two levels of valence. The results were very interesting reaching between 69% and 77% of correct discrimination between the four emotional states. Higher results (~89%) were obtained for discriminating between two levels of arousal and two levels of valence

    Inside Out: Detecting Learners' Confusion to Improve Interactive Digital Learning Environments

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    Confusion is an emotion that is likely to occur while learning complex information. This emotion can be beneficial to learners in that it can foster engagement, leading to deeper understanding. However, if learners fail to resolve confusion, its effect can be detrimental to learning. Such detrimental learning experiences are particularly concerning within digital learning environments (DLEs), where a teacher is not physically present to monitor learner engagement and adapt the learning experience accordingly. However, with better information about a learner's emotion and behavior, it is possible to improve the design of interactive DLEs (IDLEs) not only in promoting productive confusion but also in preventing overwhelming confusion. This article reviews different methodological approaches for detecting confusion, such as self-report and behavioral and physiological measures, and discusses their implications within the theoretical framework of a zone of optimal confusion. The specificities of several methodologies and their potential application in IDLEs are discussed

    Affective learning: improving engagement and enhancing learning with affect-aware feedback

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    This paper describes the design and ecologically valid evaluation of a learner model that lies at the heart of an intelligent learning environment called iTalk2Learn. A core objective of the learner model is to adapt formative feedback based on students’ affective states. Types of adaptation include what type of formative feedback should be provided and how it should be presented. Two Bayesian networks trained with data gathered in a series of Wizard-of-Oz studies are used for the adaptation process. This paper reports results from a quasi-experimental evaluation, in authentic classroom settings, which compared a version of iTalk2Learn that adapted feedback based on students’ affective states as they were talking aloud with the system (the affect condition) with one that provided feedback based only on the students’ performance (the non-affect condition). Our results suggest that affect-aware support contributes to reducing boredom and off-task behavior, and may have an effect on learning. We discuss the internal and ecological validity of the study, in light of pedagogical considerations that informed the design of the two conditions. Overall, the results of the study have implications both for the design of educational technology and for classroom approaches to teaching, because they highlight the important role that affect-aware modelling plays in the adaptive delivery of formative feedback to support learning

    Virtual environments promoting interaction

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    Virtual reality (VR) has been widely researched in the academic environment and is now breaking into the industry. Regular companies do not have access to this technology as a collaboration tool because these solutions usually require specific devices that are not at hand of the common user in offices. There are other collaboration platforms based on video, speech and text, but VR allows users to share the same 3D space. In this 3D space there can be added functionalities or information that in a real-world environment would not be possible, something intrinsic to VR. This dissertation has produced a 3D framework that promotes nonverbal communication. It plays a fundamental role on human interaction and is mostly based on emotion. In the academia, confusion is known to influence learning gains if it is properly managed. We designed a study to evaluate how lexical, syntactic and n-gram features influence perceived confusion and found results (not statistically significant) that point that it is possible to build a machine learning model that can predict the level of confusion based on these features. This model was used to manipulate the script of a given presentation, and user feedback shows a trend that by manipulating these features and theoretically lowering the level of confusion on text not only drops the reported confusion, as it also increases reported sense of presence. Another contribution of this dissertation comes from the intrinsic features of a 3D environment where one can carry actions that in a real world are not possible. We designed an automatic adaption lighting system that reacts to the perceived user’s engagement. This hypothesis was partially refused as the results go against what we hypothesized but do not have statistical significance. Three lines of research may stem from this dissertation. First, there can be more complex features to train the machine learning model such as syntax trees. Also, on an Intelligent Tutoring System this could adjust the avatar’s speech in real-time if fed by a real-time confusion detector. When going for a social scenario, the set of basic emotions is well-adjusted and can enrich them. Facial emotion recognition can extend this effect to the avatar’s body to fuel this synchronization and increase the sense of presence. Finally, we based this dissertation on the premise of using ubiquitous devices, but with the rapid evolution of technology we should consider that new devices will be present on offices. This opens new possibilities for other modalities.A Realidade Virtual (RV) tem sido alvo de investigação extensa na academia e tem vindo a entrar na indústria. Empresas comuns não têm acesso a esta tecnologia como uma ferramenta de colaboração porque estas soluções necessitam de dispositivos específicos que não estão disponíveis para o utilizador comum em escritório. Existem outras plataformas de colaboração baseadas em vídeo, voz e texto, mas a RV permite partilhar o mesmo espaço 3D. Neste espaço podem existir funcionalidades ou informação adicionais que no mundo real não seria possível, algo intrínseco à RV. Esta dissertação produziu uma framework 3D que promove a comunicação não-verbal que tem um papel fundamental na interação humana e é principalmente baseada em emoção. Na academia é sabido que a confusão influencia os ganhos na aprendizagem quando gerida adequadamente. Desenhámos um estudo para avaliar como as características lexicais, sintáticas e n-gramas influenciam a confusão percecionada. Construímos e testámos um modelo de aprendizagem automática que prevê o nível de confusão baseado nestas características, produzindo resultados não estatisticamente significativos que suportam esta hipótese. Este modelo foi usado para manipular o texto de uma apresentação e o feedback dos utilizadores demonstra uma tendência na diminuição do nível de confusão reportada no texto e aumento da sensação de presença. Outra contribuição vem das características intrínsecas de um ambiente 3D onde se podem executar ações que no mundo real não seriam possíveis. Desenhámos um sistema automático de iluminação adaptativa que reage ao engagement percecionado do utilizador. Os resultados não suportam o que hipotetizámos mas não têm significância estatística, pelo que esta hipótese foi parcialmente rejeitada. Três linhas de investigação podem provir desta dissertação. Primeiro, criar características mais complexas para treinar o modelo de aprendizagem, tais como árvores de sintaxe. Além disso, num Intelligent Tutoring System este modelo poderá ajustar o discurso do avatar em tempo real, alimentado por um detetor de confusão. As emoções básicas ajustam-se a um cenário social e podem enriquecê-lo. A emoção expressada facialmente pode estender este efeito ao corpo do avatar para alimentar o sincronismo social e aumentar a sensação de presença. Finalmente, baseámo-nos em dispositivos ubíquos, mas com a rápida evolução da tecnologia, podemos considerar que novos dispositivos irão estar presentes em escritórios. Isto abre possibilidades para novas modalidades

    Biometric features modeling to measure students engagement.

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    The ability to measure students’ engagement in an educational setting may improve student retention and academic success, revealing which students are disinterested, or which segments of a lesson are causing difficulties. This ability will facilitate timely intervention in both the learning and the teaching process in a variety of classroom settings. In this dissertation, an automatic students engagement measure is proposed through investigating three main engagement components of the engagement: the behavioural engagement, the emotional engagement and the cognitive engagement. The main goal of the proposed technology is to provide the instructors with a tool that could help them estimating both the average class engagement level and the individuals engagement levels while they give the lecture in real-time. Such system could help the instructors to take actions to improve students\u27 engagement. Also, it can be used by the instructor to tailor the presentation of material in class, identify course material that engages and disengages with students, and identify students who are engaged or disengaged and at risk of failure. A biometric sensor network (BSN) is designed to capture data consist of individuals facial capture cameras, wall-mounted cameras and high performance computing machine to capture students head pose, eye gaze, body pose, body movements, and facial expressions. These low level features will be used to train a machine-learning model to estimate the behavioural and emotional engagements in either e-learning or in-class environment. A set of experiments is conducted to compare the proposed technology with the state-of-the-art frameworks in terms of performance. The proposed framework shows better accuracy in estimating both behavioral and emotional engagement. Also, it offers superior flexibility to work in any educational environment. Further, this approach allows quantitative comparison of teaching methods, such as lecture, flipped classrooms, classroom response systems, etc. such that an objective metric can be used for teaching evaluation with immediate closed-loop feedback to the instructor
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