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Elshaw, Mark. "Multimodal neural grounding of language processing for robot actions." Thesis, University of Sunderland, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420517.
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Brooks, Jessica. "How actions alter sensory processing: reafference cancellation in the vestibular system." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=106238.
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Our sensory systems are continually confronted with the task of differentiating sensory inputs due to external events (exafference) from sensory information due to our own actions (reafference). Discriminating between these two types of stimuli is critical in order to achieve accurate perception and motor control. The current mechanism that explains how the vestibular system deals with this issue states that during an active movement, a prediction of the sensory consequences of motor commands computed by an internal model is compared to the actual sensory feedback; if the internal model's prediction and sensory feedback match, the vestibular signal is cancelled, if they do not, the vestibular signal is left unaltered. The studies presented in this thesis were aimed at understanding this fundamental mechanism. In particular, I investigate 1- the rules that govern the cancellation of vestibular reafference, 2- the adaptability of the internal model that underlies vestibular reafference cancellation and 3-the role of the vestibular cerebellum in the processing of passive and active motion. First, I establish that disrupting sensory feedback during an active movement affects the ability of central vestibular neurons to suppress vestibular reafference. Specifically, when proprioceptive feedback is disrupted during an active movement, vestibular reafference is no longer suppressed. In addition, I demonstrate that vestibular reafference due to active body movements are suppressed at the first central stage of vestibular processing. Second, I demonstrate that the internal model underlying the suppression of vestibular reafference adapts such that vestibular neurons regain the ability to suppress vestibular reafference in conditions when the relationship between motor commands and the actual head movements are altered. My findings strongly suggest that indeed the internal model used to predict the sensory consequences of motor commands is quickly updated when faced with new relationships between expected and actual sensory feedback.Finally, I examine the role that the cerebellum plays in the encoding of passive versus active motion. I found that in the passive condition, neurons in the rostral fastigial nucleus (FN) encode two separate representations of motion; half the neurons encode head motion and the other half encodes body motion. The neurons in the rostral FN that encode body movements provide the first neuronal correlate for the perception of body motion. Then I address how vestibular information is processed by the rostral FN during active movements. We found that neurons in the vestibular cerebellum were attenuated during active head and body motion and demonstrate for the first time that the primate cerebellum explicitly encodes the detailed time course of exafference. Taken together the results in this thesis provide firm evidence that vestibular reafference is suppressed during active head and body motion by a mechanism that compares the brain's internally generated expectation of the consequences of voluntary movements with the actual incoming sensory information.Nos systèmes sensoriels doivent continuellement faire la différence entre des sensations dues aux événements extérieurs (exaférence) et des sensations provoquées par nos propres actions (réafférence). Faire la différence entre ces deux types de stimuli est essential pour permettre une perception et un control moteur précis. Cette distinction est possible, au niveau du système vestibulaire, grâce au fait qu'une prédiction des conséquences sensorielles de la commande motrice évaluée par un modèle interne est comparée avec le retour sensorielle réel; si la prédiction du model interne est similaire au retour sensoriel, le signale vestibulaire est supprimé; si ils sont différent, le signal vestibulaire n'est pas altéré. Les études présentées dans cette thèse ont pour but de comprendre ce mécanisme fondamental. Plus particulièrement, je cherche a établir 1- les règles qui gouvernent la suppression des réafférences vestibulaire, 2- l'adaptabilité du modèle interne qui sous-tend la suppression des réafférences vestibulaire et 3- le rôle du cervelet vestibulaire dans le processus de différentiation des mouvements actif et passif.Premièrement, j'ai montré que déranger le retour sensoriel pendant un mouvement actif perturbe la capacité des neurones vestibulaire centraux à supprimer les réafférences vestibulaire. Plus précisément, quand le retour proprioceptif est perturbé pendant un mouvement actif, le retour vestibulaire n'est plus supprimé. De plus, j'ai démontré que le retour vestibulaire due à des mouvements du corps est aussi supprimé au premier niveau central du traitement vestibulaire.Deuxièmement, j'ai démontré que le model interne sous-tendant la suppression des réafférences vestibulaire s'adapte pour que les neurones vestibulaire retrouvent leur capacité à supprimer les réafférences vestibulaire dans des conditions ou la relation entre la commande motrice et le mouvement de la tète sont perturbé. Mes résultats suggèrent fortement que le model interne utilisé pour prédire les conséquences sensorielles de la commande motrice est rapidement mis a jour quand il est en présence de nouvelles relations entre retour sensoriel attendu et réel. Finalement, je me suis intéressé au rôle que joue le cervelet pour encoder les mouvements passif et actif. J'ai trouvé qu'en condition passive, les neurones du noyau rostral de fastigial (FN rostral) encodent deux représentations différentes du mouvement; la moitié des neurones encodent les mouvements de la tète et l'autre moitié encode les mouvements du corps. Les neurones du FN rostral qui encodent les mouvements du corps fournissent le premier corrélat neural de la perception des mouvements du corps. Puis j'aborde la question de comment l'information vestibulaire est traite par le FN rostral pendant les mouvements actifs? Nous avons trouvé que la réponse des neurones dans le cervelet vestibulaire est atténuée pendant les mouvements actifs de la tète et du corps. Cela démontre pour la première fois que le cervelet des primates encode les exafférences.Dans leur ensemble les résultats de cette thèse fournissent des évidences solides en faveur de la suppression des réafférences vestibulaire pendant les mouvements actifs de la tète et du corps. Cette suppression est possible grâce à un mécanisme qui compare les prévisions des conséquences d'un mouvement volontaire générées par le cerveau avec le retour sensoriel réel.
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Good, Daniel A. "Error Processing and Naturalistic Actions Following Moderate-to-Severe Traumatic Brain Injury." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3804.
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Moderate-to-severe traumatic brain injury (M/S TBI) can affect an individual's ability to perform daily tasks. For example, individuals with M/S TBI are more likely to commit errors on tasks such as making a meal or wrapping a present. The neural processes involved in such errors are poorly understood. Studies suggest that neurophysiologic markers of cognitive control and error processing may be helpful in gaining additional insight into errors on naturalistic action tasks. Unfortunately, previous experimental methods left a methodological gap which limited the use of neurophysiological markers in the study of naturalistic action. Several recent studies in healthy adults have suggested one method of bridging the gap by having individuals observe another person's errors. The current study was the first study to employ the method in a TBI population as a possible means of gaining additional insight into the detrimental effects of M/S TBI on the performance of naturalistic actions. In order to gain additional insight into the effects of M/S TBI on the completion of naturalistic tasks I used two neurophysiologic markers of cognitive control and error processing. They were the observer error related negativity (oERN) and the P300 components of the scalp-recorded event-related potential (ERP). I hypothesized that individuals with M/S TBI would demonstrate error-specific changes in the two oERN and P300 that would correlate with self-reported difficulties in daily functioning. The study consisted of two experiments. One compared 15 individuals with M/S TBI to 17 demographically similar healthy controls on an error related naturalistic action based picture task. The second compared an overlapping sample of 16 individuals with M/S TBI to 16 demographically similar controls as they watched a confederate complete the Erikson flanker task, a commonly used task in the study of electrophysiological markers. Accuracy (error vs. correct) and group (M/S TBI vs. control) effects were analyzed using 2 x 2 repeated measures ANOVAs on ERP amplitude and latency. Pearson product-moment correlations were calculated to evaluate the relationship between the P300 and oERN and measures of self-reported executive functioning (Frontal Systems Behavior Scale, FrSBe) and neuropsychological measures. Findings supported a difference between the control and M/S TBI groups in how errors were processed during the naturalistic actions based picture task. There was an interaction between group membership and response accuracy (error vs. correct) on P300 amplitude and P300 latency. Controls demonstrated reduced P300 amplitude and latency on error trials compared to correct trials. Individuals with M/S TBI did not demonstrate a significant difference between correct trials and error trials on P300 amplitude and latency. The amplitude and latency of the P300 were correlated with self-reported functional difficulties in individuals with M/S TBI but not control participants. A Fisher's r -- z analysis indicated that correlations differed significantly between groups; however, an outlier was identified in the correlational data. Removal of the outlier data led to non-significant results in the Fisher's r -- z analysis. Taken together, results of the picture task supplied evidence that for individuals with M/S TBI differences in neurophysiologic markers between groups could be explained by reduced adaptation to complexity or by possible deficits in a secondary error processing pathway for complex errors. Future research could focus on better defining the functional relationship between P300 amplitude and latency and increased errors in naturalistic actions following M/S TBI. Observation of the flanker task did not elicit oERN waveforms from either healthy controls or from individuals with M/S TBI. The results could be due to problems with the current task, but also raised some concerns about previous studies using the flanker task which employed a slightly different methodology requiring participants to count errors. The current study did not require participant to count errors. As a whole, the study supplied partial support for using electrophysiological markers of error processing to gain additional understanding increased errors in the performance of naturalistic actions following M/S TBI.
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Handl, Andrea. "World of faces, words and actions : Observations and neural linkages in early life." Doctoral thesis, Uppsala universitet, Institutionen för psykologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-281242.
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From the start of their lives, infants and young children are surrounded by a tremendous amount of multimodal social information. One intriguing question in the study of early social cognition is how vital social information is detected and processed and how and when young infants begin to make sense of what they see and hear and learn to understand other people’s behavior. The overall aim of this thesis was to provide new insights to this exciting field. Investigating behavior and/or neural mechanisms in early life, the three different studies included in this thesis therefore strive to increase our understanding on perception and processing of social information. Study I used eye-tracking to examine infants´ observations of gaze in a third-party context. The results showed that 9-, 16- and 24-month-old infants differentiate between the body orientations of two individuals on the basis of static visual information. More particularly, they shift their gaze more often between them when the social partners face each other than when they are turned away from each other. Using ERP technique, Study II demonstrated that infants at the age of 4 to 5 months show signs of integrating visual and auditory information at a neural level. Further, direct gaze in combination with backwards-spoken words leads to earlier or enhanced neural processing in comparison to other gaze-word combinations. Study III, also an EEG investigation, found that children between 18 and 30 months of age show a desynchronization of the mu rhythm during both the observation and execution of object-directed actions. Also, the results suggest motor system activation when young children observe others’ mimed actions. To summarize, the findings reported in this thesis strengthen the idea that infants are sensitive to others´ gaze and that this may extend to third-party contexts. Also, gaze is processed together with other information, for instance words, even before infants are able to understand others’ vocabulary. Furthermore, the motor system in young children is active during both the observation and imitation of another person’s goal-directed actions. This is in line with findings in infants, children and adults, indicating that these processes are linked at neural level.
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Noonan, MaryAnn Philomena. "Linking actions to outcomes in the frontal lobe." Thesis, University of Oxford, 2010. http://ora.ox.ac.uk/objects/uuid:e1bcccd1-2182-4f1d-94bd-b80ce67efb0e.
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Behaviour is guided by accumulated experience, valuation and comparison. While many aspects associated with these functions are mediated by the frontal lobes, the precise contribution from particular regions remains debated. This thesis will deal with how an organism comes to select an option and will specifically focus on the role of the orbitofrontal cortex (OFC) in two mechanisms in this process: learning of outcome specificities and selecting between multiple options based on their expected values. Despite evidence emphasizing anatomical and connective heterogeneity within this structure, the OFC is often regarded as a uniform region. This thesis aims to resolve some of this uncertainty by assuming that the medial and lateral regions of the OFC contribute differentially to learning and decision-making. Two distinct methodologies were used in these investigations. First, the contribution of the medial OFC to social and emotional processing was examined. The findings from this study disprove previously held beliefs that the medial regions of the OFC guide social and emotional behaviours, but indicted a role for this region in value-guided decision-making. The second study examined functional differences between the lateral and medial OFC by making circumscribed lesions to either region in macaque monkeys. The animals performed a number of 3-armed bandit tasks which were designed to investigate different aspects of value assignment and comparison. The results show that while lateral OFC was required for "credit assignment" – the correct assignment of values to visual cues – medial OFC was critical for comparison of the cues' values during decision-making. In unchanging probabilistic environments, mOFC lesions induced decision-making impairments when value comparison was difficult without affecting credit assignment and associative learning. By contrast, lateral OFC lesions caused the opposite pattern of impairment. The final study used human-neuroimaging techniques to investigate the differential representation of outcome-specific contingency learning and found not only that the expectation of a unique outcome facilitated learning and memory recall but that this was supported by a neural network which included the lateral regions of the OFC and the anterior cingulate cortex. Activity in the mOFC did not correlate with outcome-specific contingency learning but instead reflected both the value associated with the receipt and expectation of a reward. Taken together, the results from this thesis suggest that specific parts of the OFC make markedly different contributions to these very different cognitive functions.
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Metzler, Hannah. "The influence of bodily actions on social perception and behaviour : assessing effects of power postures." Thesis, Sorbonne université, 2018. http://www.theses.fr/2018SORUS287/document.
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Les postures corporelles signalant domination ou soumission servent une fonction de communication chez les humains et d’autres animaux. La question de savoir si l'adoption de telles "postures de pouvoir" influence la perception et le comportement de l'agent fait actuellement l'objet d'un débat. Le travail réalisé pendant cette thèse consistait à explorer les effets de ces postures sur des comportements étroitement liés à leur fonction primaire, à savoir la communication sociale, en se focalisant sur les réponses aux visages, signaux sociaux particulièrement saillants. Dans une série d'expériences, j'ai utilisé des méthodes de corrélation inverse pour visualiser les représentations mentales de traits préférés du visage. Les représentations mentales des visages préférés implicitement et explicitement évoquaient une impression affiliative et légèrement dominante, mais ne révélaient aucun effet reproductible des postures. Deux autres expériences distinctes ont étudié les effets de la posture sur la perception d’expressions faciales menaçantes et sur les comportements d'approche ou d'évitement en réponse à ces signaux. Bien que les postures n'aient pas d’influence sur la reconnaissance explicite d’expressions faciales menaçantes, elles ont un impact sur les décisions d'approcher ou d'éviter des signaux de menace. Plus précisément, l'adoption d'une posture de soumission augmentait la tendance à éviter les personnes exprimant la colère. Enfin, une tentative de réplication des effets des postures sur les niveaux de testostérone et de cortisol a démontré que même l'adoption répétée d'une posture de pouvoir en contexte social ne provoque pas de changements hormonaux. Dans l'ensemble, ces résultats suggèrent que notre posture corporelle n’influence pas nos représentations mentales et notre perception des autres individus, mais pourrait influencer nos actions en réponse aux signaux sociauxExpansive and constrictive body postures serve a primary communicative function in humans and other animals by signalling power and dominance. Whether adopting such “power postures” influences the agent’s own perception and behaviour is currently a subject of debate. In this PhD thesis, I explored effects of adopting power postures on behaviours closely related to the postures’ primary function of social signalling by focusing on responses to faces as particularly salient social signals. In a series of experiments, I utilized reverse correlation methods to visualize mental representations of preferred facial traits. Mental representations of implicitly as well as explicitly preferred faces evoked an affiliative and slightly dominant impression, but revealed no replicable effects of power postures. Two further separate experiments investigated posture effects on the perception of threatening facial expressions, and approach vs. avoidance actions in response to such social signals. While postures did not influence explicit recognition of threatening facial expressions, they affected approach and avoidance actions in response to them. Specifically, adopting a constrictive posture increased the tendency to avoid individuals expressing anger. Finally, an attempt to replicate posture effects on levels of testosterone and cortisol demonstrated that even repeatedly adopting a power posture in a social context does not elicit hormonal changes. Altogether, these findings suggest that our body posture does not influence our mental representations and perception of other people’s faces per se, but could influence our actions in response to social signals
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Spasic, Nemanja. "Anomaly Detection and Prediction of Human Actions in a Video Surveillance Environment." Thesis, University of Cape Town, 2007. http://pubs.cs.uct.ac.za/archive/00000449/.
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World wide focus has over the years been shifting towards security issues, not in least due to recent world wide terrorist activities. Several researchers have proposed state of the art surveillance systems to help with some of the security issues with varying success. Recent studies have suggested that the ability of these surveillance systems to learn common environmental behaviour patterns as wells as to detect and predict unusual, or anomalous, activities based on those learnt patterns are possible improvements to those systems. In addition, some of these surveillance systems are still run by human operators, who are prone to mistakes and may need some help from the surveillance systems themselves in detection of anomalous activities. This dissertation attempts to address these suggestions by combining the fields of Image Understanding and Artificial Intelligence, specifically Bayesian Networks, to develop a prototype video surveillance system that can learn common environmental behaviour patterns, thus being able to detect and predict anomalous activity in the environment based on those learnt patterns. In addition, this dissertation aims to show how the prototype system can adapt to these anomalous behaviours and integrate them into its common patterns over a prolonged occurrence period. The prototype video surveillance system showed good performance and ability to detect, predict and integrate anomalous activity in the evaluation tests that were performed using a volunteer in an experimental indoor environment. In addition, the prototype system performed quite well on the PETS 2002 dataset 1, which it was not designed for. The evaluation procedure used some of the evaluation metrics commonly used on the PETS datasets. Hence, the prototype system provides a good approach to anomaly detection and prediction using Bayesian Networks trained on common environmental activities.
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Flatters, Sarah Jane Louise. "The effect of nerve injury on the spinal and peripheral actions of galanin and interleukin-6 on sensory processing." Thesis, University College London (University of London), 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268771.
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Münster, Katja [Verfasser], Pia [Akademischer Betreuer] Knoeferle, and Stavros [Akademischer Betreuer] Skopeteas. "Effects of emotional facial expressions and depicted actions on situated language processing across the lifespan / Katja Münster ; Pia Knoeferle, Stavros Skopeteas." Bielefeld : Universitätsbibliothek Bielefeld, 2016. http://d-nb.info/1121187595/34.
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Decroix, Jérémy. "Dynamics of processing of visual kinematics and goal-related information during the recognition of object directed actions : behavioural and neurophysiological evidence." Thesis, Lille 3, 2020. https://pepite-depot.univ-lille.fr/RESTREINT/EDSHS/2020/2020LIL3H005.pdf.
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Les actions sont des mouvements complexes dirigés vers un but. En dépit du fait que ces buts ne soient pas directement visibles, nous parvenons, en tant qu’observateur, à les identifier et à les anticiper avec succès. Dans cette thèse, nous avons identifié deux approches pour expliquer comment, en tant qu’observateur, nous parvenons à reconnaitre les actions d’autrui. Les approches sensorimotrices considèrent la reconnaissance des actions d’autrui comme une propagation ascendante de la perception des gestes à la reconnaissance des buts. Les gestes sont vus ici comme la principale source d’information à partir de laquelle le but de l’acteur peut être extrait. A l’opposé, les approches prédictives considèrent que l’observateur ne peut pas comprendre les gestes de l’autre sans préalablement prédire son but probable. L’observateur doit donc extraire le but probable de l’action à partir d’autres sources d’information pour le guider dans son traitement des gestes observés. Les connaissances sur le traitement dynamique des gestes observés d’une part et des informations sur le but d’autre part sont critiques pour dissocier ces deux approches et pour permettre une meilleure compréhension des mécanismes qui sous-tendent la reconnaissance des actions d’autrui. Néanmoins, les données empiriques dans cette direction manquent cruellement. Afin de combler cette lacune, nous nous sommes intéressés à la priorité donnée aux gestes observés relativement à celle donnée aux informations sur le but lors de la reconnaissance des actions d’autrui. La contribution des informations sur le geste observé et sur le but a été évaluée indépendamment grâce à l’introduction de violation de geste et/ou de but dans des photographies d’actions dirigées vers des objets. Grâce à des méthodes comportementales (amorçage et tâche de recherche visuelle), nous avons constaté que les informations liées au but sont priorisées durant les premiers stades du traitement visuel des actions, alors que les informations liées aux gestes observés sont priorisées durant les derniers stades du traitement visuel des actions. Grâce à des méthodes neurophysiologiques (potentiels évoqués et stimulation magnétique transcrânienne), nous avons observé que si les deux types d’information sont décodées dès les stades perceptifs du traitement des actions, c’est le traitement informations sur le but (et non sur le geste) qui guide les étapes sémantiques du traitement des actions. Nous apportons par ailleurs des arguments justifiant de l’implication critique du réseau fronto-pariétal dans l’intégration des deux sources d’information. Enfin, nous montrons que la tendance à donner plus d’importance aux informations sur le but relativement à celles sur les gestes observés dépend de caractéristiques individuelles. Dans l’ensemble, les données rapportées ici sont en accord avec les approches prédictives de la reconnaissance des actions. Ces résultats sont discutés à la lumière d’un faisceau d’arguments qui suggèrent que les gestes observés sont utilisés pour mettre à jours des prédictions sur le but de l’acteur, elles-mêmes préalablement dérivées d’autres sources d’informations. Nos données nous amènent finalement à envisager une approche pluraliste de la reconnaissance des actions observées, avec un ensemble de stratégies dont l’usage varie en fonction des situations et des individusActions are complex, goal-directed, movements, and despite being hidden in the actor’s mind, observers successfully identify and anticipate actor’s goal. In this thesis, we identified two main approaches to explain how observers recognise others’ actions. Sensorimotor approaches consider action recognition as bottom-up propagation from the perception of visual kinematics to the recognition of action goals. Visual kinematics are viewed here as the primary source of visual information from which goal-related information is extracted. In contrast, predictive approaches assume that observers cannot make sense of visual kinematics without a prediction about the actor’s goal. Observers would extract goal-related information from non-motor sources of information to guide the processing of the visual kinematics. Information about the temporal dynamics of activation of visual kinematics and goal-related information during action visual processing is critical to disentangle the two approaches and to provide a better understanding of the mechanisms underlying action recognition, but empirical data in this direction are clearly lacking. In order to fill this gap, we investigated the relative priority given to visual kinematics versus non-motor goal-related information during the recognition of others’ actions. The contribution of visual kinematics and non-motor goal-related information was independently evaluated by introducing violations of grip and/or visual goal in photographs of object-directed actions. Using behavioural methods (priming and visual-search paradigms), we demonstrated that non-motor goal-related information was prioritised over visual kinematics during the first steps of visual action processing, whereas visual kinematics were prioritised over goal-related information later during visual action processing. Using neurophysiological methods (event-related potential and transcranial magnetic stimulation priming paradigms), we found that both visual kinematics and non-motor goal-related information are already processed during the perceptual stages of action processing, but that action semantic processing is guided by goal-related information rather than visual kinematics. We further provide evidence supporting the critical involvement of the frontoparietal network in the later integration of visual kinematics and non-motor goal-related information. We finally showed that the priority given to non-motor goal-related information over visual kinematics during action visual processing depends on individual social characteristics. Together, the findings reported are consistent with predictive approaches of action recognition. Results are discussed in the light of converging evidence suggesting that visual kinematics are used to update goal predictions that have been previously derived from non-motor goal-related information. Yet findings further orient towards a pluralist view of action understanding, in which the strategies used to process others’ actions may vary depending on situations and individuals
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Khan, Muhammad Sikandar Lal. "Presence through actions : theories, concepts, and implementations." Doctoral thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-138280.
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During face-to-face meetings, humans use multimodal information, including verbal information, visual information, body language, facial expressions, and other non-verbal gestures. In contrast, during computer-mediated-communication (CMC), humans rely either on mono-modal information such as text-only, voice-only, or video-only or on bi-modal information by using audiovisual modalities such as video teleconferencing. Psychologically, the difference between the two lies in the level of the subjective experience of presence, where people perceive a reduced feeling of presence in the case of CMC. Despite the current advancements in CMC, it is still far from face-to-face communication, especially in terms of the experience of presence. This thesis aims to introduce new concepts, theories, and technologies for presence design where the core is actions for creating presence. Thus, the contribution of the thesis can be divided into a technical contribution and a knowledge contribution. Technically, this thesis details novel technologies for improving presence experience during mediated communication (video teleconferencing). The proposed technologies include action robots (including a telepresence mechatronic robot (TEBoT) and a face robot), embodied control techniques (head orientation modeling and virtual reality headset based collaboration), and face reconstruction/retrieval algorithms. The introduced technologies enable action possibilities and embodied interactions that improve the presence experience between the distantly located participants. The novel setups were put into real experimental scenarios, and the well-known social, spatial, and gaze related problems were analyzed. The developed technologies and the results of the experiments led to the knowledge contribution of this thesis. In terms of knowledge contribution, this thesis presents a more general theoretical conceptual framework for mediated communication technologies. This conceptual framework can guide telepresence researchers toward the development of appropriate technologies for mediated communication applications. Furthermore, this thesis also presents a novel strong concept – presence through actions - that brings in philosophical understandings for developing presence- related technologies. The strong concept - presence through actions is an intermediate-level knowledge that proposes a new way of creating and developing future 'presence artifacts'. Presence- through actions is an action-oriented phenomenological approach to presence that differs from traditional immersive presence approaches that are based (implicitly) on rationalist, internalist views.
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Talha, Sid Ahmed Walid. "Apport des techniques d'analyse et de traitement de données pour la reconnaissance des actions en vue d'un suivi du comportement humain." Thesis, Ecole nationale supérieure Mines-Télécom Lille Douai, 2020. http://www.theses.fr/2020MTLD0006.
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Pour lutter contre la perte d’autonomie liée au vieillissement dû à des altérations physiques et/ou psychiques, les nouvelles technologies, oeuvrent à retarder sa survenue, la détecter, l’évaluer et proposer des solutions modernes et innovantes. Dans ce contexte, notre projet de thèse vise à exploiter l’apport des techniques d’analyse et de traitement de données pour le suivi du comportement humain.Cette thèse cible deux parties importantes et complémentaires : la première réalise la synthèse journalière de l’ensemble des actions effectuées par la personne, afin de nous renseigner sur son degré d’autonomie. La deuxième partie propose une solution moderne basée sur l’exécution d’exercices physiques sous forme de mouvements contrôlés reconnus et corrigés.A partir d’une base de données de signaux acquis d’un accéléromètre et d’un gyroscope embarqués dans un smartphone, nous avons développé et mis en place un système intelligent pour la reconnaissance de l’action. Nous nous sommes tout d’abord intéressés à la construction d’un vecteur d’attributs pertinent et optimal suivant le problème de classification rencontré. Notre algorithme de sélection d’attributs est exécuté au niveau de chaque nœud interne de l’approche de classification nous permettant ainsi d’obtenir des performances supérieures aux différents travaux existants dans la littérature. Cette démarche a permis de classer trois catégories d’actions intiment corrélées avec l’autonomie et le bien-être : les actions sédentaires, les actions périodiques ou pseudo-périodiques et les actions non périodiques. Ce système reconnaît aussi six transitions posturales négligées dans la littérature mais importantes pour l’autonomie et le bien-être. Notre approche nous garantit la robustesse à l’emplacement des capteurs et permet de réduire considérablement le temps de calcul nécessaire pour reconnaître l’action.A la base des actions effectuées par la personne durant la journée, un indicateur d’autonomie pourra être établi. Pour maintenir cette autonomie et pallier au risque de la perdre, il est important de s’entretenir physiquement. Dans ce contexte, nous proposons un second système intelligent de reconnaissance de l’action humaine basé sur des données squelette acquis à partir d’une caméra Kinect. Un nouvel algorithme d’extraction d’attributs en temps réel appelé BDV (Body-part Directional Velocity) a été proposé. Dans ce cas le système intelligent de reconnaissance de l’action est basé sur les modèles de Markov cachés (HMMs) avec des distributions de sortie d’état représentées par des modèles de mélange gaussiens (GMMs). Les résultats expérimentaux sur deux jeux de données publiques ont démontré l’efficacité de notre approche et sa supériorité par rapport aux approches de l’état de l’art. L’invariance et la robustesse de l’approche à l’orientation ont été aussi abordées en positionnant ainsi notre technique parmi les meilleures approches testées sur deux jeux de données présentation ce challenge.La reconnaissance anticipée de l’action par notre système a aussi été considérée en montrant que la moitié des actions étaient prévisibles presque au milieu de l’ensemble de la séquence de données squelette, et que certaines classes ont été reconnues avec seulement 4 % de l’ensemble des données de la séquenceTo prevent the loss of autonomy linked to aging due to physical and / or psychological alterations, new technologies are working to delay its occurrence, detect it, assess it by offering modern and innovative solutions. In this context, our thesis project aims to exploit the contribution of analysis and data processing techniques for monitoring human behavior.This thesis targets two important and complementary parts: the first carries out the daily action recognition performed by a person, to inform us about his degree of autonomy. The second part offers a modern solution to maintain autonomy, it is based on the execution of physical exercices.From a datasets of signals collected by an accelerometer and a gyroscope embedded in a smartphone, we have developed and implemented an intelligent system for action recognition. We were first interested in the construction of a relevant and optimal feature vector according to the classification problem encountered. Our feature selection algorithm is executed at the level of each internal node of the classification approach, thus allowing us to outperform various state-of-the-art methods. Out approach carries out the classification of three categories of actions highly correlated with autonomy and well-being: sedentary actions, periodic or pseudo-periodic actions, and non-periodic actions. Our system also recognizes six postural transitions important for autonomy and well-being. The proposed approach guarantees robustness in the location of sensors and considerably reduces the computation time necessary to recognize the action.Based on actions carried out by the person during the day, an autonomy indicator can be established. To maintain this autonomy and decrease the risk of losing it, it is important to practice physical exercises. In this context, we propose a second intelligent system to recognize human actions based on skeleton data collected from a Kinect camera. A new algorithm for feature extraction in real-time called BDV (Body-part Directional Velocity) has been proposed. The classification of actions is based on hidden Markov models (HMMs) with state output distributions represented by Gaussian mixing models (GMMs). Experimental results on public datasets have demonstrated the effectiveness of our approach and its superiority over state-of-the-art methods. The invariance and robustness to the orientation of the camera were also addressed, thus positioning our technique among the best approaches on two datasets presenting this challenge. The early recognition of the action by our system was also considered by showing that half of the actions were predictable almost in the middle of the entire sequence of skeleton data and that some classes were recognized with only 4% of the sequence
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Lermuzeaux, Jean-Marc. "Contribution à l'intégration des niveaux de traitement automatique de la langue écrite : ANAEL : un environnement de compréhension basé sur les objets, les actions et les grammaires d'événements." Caen, 1988. http://www.theses.fr/1988CAEN2029.
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L'environnement ANAEL est basé sur une représentation des connaissances sous forme d'objets et d'actions et sur les grammaires d'événements. ANAEL s'articule sur trois niveaux : 1) le niveau acquisition des modèles réel et linguistique ; 2) le niveau compréhension où un interpréteur manipule une base de connaissances en langage naturel et 3) le niveau méta où les modèles sont considérés comme des faits
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Silva, João Roberto da Mota. "Propostas e instrumentos adotados na implantação da gestão democrática em Maceió (Alagoas 1993 1996)." Pontifícia Universidade Católica de São Paulo, 2012. https://tede2.pucsp.br/handle/handle/9646.
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Previous issue date: 2012-03-23This study presents an analysis of the process of introduction of the democratic management in the schools of the municipal system of teaching in Maceió/Alagoas and the actions that transformed the teaching in the period from 1993 to 1996. The systematization of the registers of this inquiry was organized in two chapters: the first treats Maceió public politics and democratic management and the second, the democratic management in the system of teaching of Maceió, historical, reality and results. It had as objective to investigate the school impact of the schools of the municipal system during the introduction, when it take as a reference the voice of the teachers, of the technicians and of the educators administrators what were responsible authors for realization of the process. The adopted methodology leaves from a bibliographical and documentary study, through the historical registers of the actions and of the ideas that allowed to introduce the democratic management in the education in the local authority of Maceió, confronting with official documents: Federal Constitution; National Plan of Education; Law of Guidelines and Bases; Municipal Organic Law; Status of the Theaching; Rules of Schools and School Boards and Plan of Action for the Education of Maceió. It is hoped that this study can contribute to a new reflection on the educational process in school management in order to accomplish new actions to eradicate school failure and dropout, with direct management in schools and transparency in the implementation of public money
Esse estudo apresenta uma análise do processo de implantação da gestão democrática nas escolas da rede municipal de ensino em Maceió/Alagoas e as ações que transformaram o ensino no período de 1993 a 1996. A sistematização dos registros desta pesquisa foi organizada em dois capítulos: o primeiro trata de Maceió políticas públicas e gestão democrática e o segundo, da gestão democrática no sistema de ensino de Maceió, histórico, realidade e resultados. Teve como objetivo investigar o impacto escolar das escolas da rede municipal durante a implantação, tendo como referência a voz dos professores, dos técnicos e dos educadores gestores que foram autores responsáveis para realização do processo. A metodologia adotada parte de um estudo bibliográfico e documental, por meio dos registros históricos das ações e das ideias que permitiram implantar a gestão democrática na educação no município de Maceió, confrontando com documentos oficiais: Constituição Federal; Plano Nacional de Educação; Lei de Diretrizes e Bases; Lei Orgânica Municipal; Estatuto do Magistério; Regimento das Escolas e dos Conselhos Escolares e o Plano de Ação para a Educação de Maceió. Espera-se que este estudo possa contribuir para uma nova reflexão sobre o processo educativo da gestão na escola, no sentido de efetivar novas ações de erradicação da evasão e da reprovação escolar, com gerenciamento direto nas escolas e transparência na aplicação do dinheiro público
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Dielmann, Alfred. "Automatic recognition of multiparty human interactions using dynamic Bayesian networks." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4022.
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Relating statistical machine learning approaches to the automatic analysis of multiparty communicative events, such as meetings, is an ambitious research area. We have investigated automatic meeting segmentation both in terms of “Meeting Actions” and “Dialogue Acts”. Dialogue acts model the discourse structure at a fine grained level highlighting individual speaker intentions. Group meeting actions describe the same process at a coarse level, highlighting interactions between different meeting participants and showing overall group intentions. A framework based on probabilistic graphical models such as dynamic Bayesian networks (DBNs) has been investigated for both tasks. Our first set of experiments is concerned with the segmentation and structuring of meetings (recorded using multiple cameras and microphones) into sequences of group meeting actions such as monologue, discussion and presentation. We outline four families of multimodal features based on speaker turns, lexical transcription, prosody, and visual motion that are extracted from the raw audio and video recordings. We relate these lowlevel multimodal features to complex group behaviours proposing a multistreammodelling framework based on dynamic Bayesian networks. Later experiments are concerned with the automatic recognition of Dialogue Acts (DAs) in multiparty conversational speech. We present a joint generative approach based on a switching DBN for DA recognition in which segmentation and classification of DAs are carried out in parallel. This approach models a set of features, related to lexical content and prosody, and incorporates a weighted interpolated factored language model. In conjunction with this joint generative model, we have also investigated the use of a discriminative approach, based on conditional random fields, to perform a reclassification of the segmented DAs. The DBN based approach yielded significant improvements when applied both to the meeting action and the dialogue act recognition task. On both tasks, the DBN framework provided an effective factorisation of the state-space and a flexible infrastructure able to integrate a heterogeneous set of resources such as continuous and discrete multimodal features, and statistical language models. Although our experiments have been principally targeted on multiparty meetings; features, models, and methodologies developed in this thesis can be employed for a wide range of applications. Moreover both group meeting actions and DAs offer valuable insights about the current conversational context providing valuable cues and features for several related research areas such as speaker addressing and focus of attention modelling, automatic speech recognition and understanding, topic and decision detection.
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Chidichima, Antonio Carlos. "Estratégias para agregação de valor à cadeia agroindustrial da tilapicultura: subsídios técnicos para implantação do selo de Indicação Geográfica." Universidade Estadual do Oeste do Paraná, 2018. http://tede.unioeste.br/handle/tede/4015.
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In a globalized economic environment and with the free competition making possible rivalry between diverse economy sectors, it is common for those who can manage their potential and better explore their skills and capabilities to stand out before their competitors. Such strategy may be applied for the Tilapia (Oreochromis niloticus) fillet production sector. This study aimed to analyze conditions that could appreciate the Tilapia fillet produced in the Western Paraná region, using Geographical Indication (GI) as a strategy of adding value to the product. The study was performed between 2014 and 2017 by contacting all 50 Western Paraná's cities. It identified the quantity of fish slaughtering and processing plants (driving agents) existent in the Tilapia (Oreochromis niloticus) production chain. A total of 24 plants with Municipal Inspection System (Sistema de Inspeção Municipal - SIM/POA), Brazilian Inspection System (Sistema Brasileiro de Inspeção - SISBI/POA) and Federal Inspection System (Sistema de Inspeção Federal - SIF) were found. After identifying Toledo city, state of Paraná, as the region that concentrates most slaughtering plants, this study focused those plants located in that city’s micro region. The field research was divided into three stages. Firstly, a diagnosis on the production chain characteristics was conducted by analyzing social relations between the main actors that make up this productive network. This part of the study consisted in evaluating whether there were conditions to form a cluster as well as to structure a governance model based on Social Network Analysis (SNA) technique. The existence of potential agents and the network between the actors of the chain was evident. In the second stage, studies focused on measuring the density of relationships between actors of the network were conducted to identify leaders able to articulate such relations, aiming at a possible strategy of Geographical Indication implementation. Ucinet Software usage made possible to evaluate and to identify the intensity of relations in network, the main actors and the possible leaders. Finally, in order to define the "Tilapia fillet" product, a research was conducted by collecting samples of water from purification process and from the slaughtering, manipulation process of fillet extraction, and samples of fresh and frozen fillet at nine slaughtering plants. Thus, it was possible to evaluate the product quality standardization or items that could influence the microbiological, physicochemical, components quality. As a conclusion, considering the production aspects in the region – including the similar conditions of management and of slaughtering and processing procedures among the agents of the productive chain, the Western Paraná's Tilapia fillet is a product which meets the requirements of the legislation. Therefore, this product can be applied for registration of the Geographical Indication (GI) by the National Institute of industrial Property, designating its Appellation of Origin (DO).
Em um cenário econômico globalizado e com a dinâmica da livre concorrência possibilitando a rivalidade entre dos vários setores da economia, é comum que se destaquem aqueles que conseguem administrar bem suas potencialidades, e explorar melhor suas capacidades e competências, se destacando perante aos concorrentes, o que, por exemplo, pode ser aplicado como estratégia ao setor de produção de filé de tilápia (Oreochromis niloticus). Este estudo teve como objetivo realizar uma pesquisa sobre a estrutura atual na cadeia produtiva da tilápia no oeste do Paraná, com foco em diagnosticar as condições e características inerentes ao processo produtivo, para uma possível obtenção do selo de IG para o “Filé de Tilápia do Oeste Paranaense”. O estudo foi realizado entre 2014 e 2017, através de contatos com todos os 50 municípios do oeste paranaense, para identificar quantos frigoríficos de abate e processamento de pescado (agentes motrizes) existiam na cadeia de produção da tilápia (Oreochromis niloticus), gerando um resultado de 24 unidades frigoríficas com Sistema de Inspeção Municipal (SIM/POA), Sistema Brasileiro de Inspeção (SISBI/POA), e Sistema de Inspeção Federal (SIF). Após a identificação da região onde se concentram a maior parte das plantas frigorificas, a pesquisa foi direcionada de forma aprofundada para os frigoríficos situados na microrregião de Toledo /PR. O trabalho de pesquisa de campo foi dividido em três fases, em um primeiro momento foi realizado um diagnóstico que apresentou a caracterização da cadeia, analisando as relações sociais entre os principais atores que compõem esta cadeia produtiva em forma de rede. Nesta parte do estudo consistia em avaliar se existiam condições para ser formado um Arranjo Produtivo Local (APL), e se existiam condições para estruturar um modelo de governança baseado em técnica de Análise de Redes Sociais (ARS), ficou destacada a existência de agentes potenciais e a importante rede de relacionamentos entre os elos e atores da cadeia produtiva. No segundo momento, foram realizados estudos focados em mensurar a densidade de relacionamentos entre os atores da rede, para identificar as lideranças que pudessem articular as relações visando uma possível estratégia de implementação de Indicação Geográfica. Com o uso do software Ucinet, foi possível avaliar a intensidade das relações em rede, identificando quem são os principais atores e possíveis líderes. Por último, e para caracterizar o produto “Filé de Tilápia” foi conduzida uma pesquisa com coleta de amostra de água de depuração, água do processo de abate e manipulação para a extração do filé, amostras de filé fresco e amostras de filé congelado em nove frigoríficos, objetivando avaliar a padronização da qualidade dos produtos ou pontos capazes de influenciar a qualidade microbiológica, físico-química e de componentes. Conclui-se que o produto “Filé de Tilápia da Região Oeste Paranaense” em virtude das condições da produção na região, incluindo manejo e os procedimentos de abate e processamento são semelhante entre os agentes da cadeia produtiva, o produto atende praticamente todas as conformidades exigidas pela legislação, e, portanto a cadeia produtiva tem condições de se organizar, e pleitear junto ao Instituto Nacional de Propriedade Industrial, o registro de IG na designação de Indicação de procedência (IP).
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Brown, Liana Elizabeth. "Orientation processing for recognition and action." Adobe Acrobat reader required to view the full dissertation, 1999. http://www.etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-239/index.html.
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Olofson, Eric Lee. "Infants' processing of action for gist /." Connect to title online (Scholars' Bank) Connect to title online (ProQuest), 2008. http://hdl.handle.net/1794/8294.
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Thesis (Ph. D.)--University of Oregon, 2008.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 118-125). Also available online in Scholars' Bank; and in ProQuest, free to University of Oregon users.
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Klepp, Anne [Verfasser]. "Neurophysiological investigations on action word processing / Anne Klepp." Düsseldorf : Universitäts- und Landesbibliothek der Heinrich-Heine-Universität Düsseldorf, 2015. http://d-nb.info/1073969940/34.
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Smirnov, Sergey, Matthias Weidlich, Jan Mendling, and Mathias Weske. "Action patterns in business process models." Universität Potsdam, 2009. http://opus.kobv.de/ubp/volltexte/2009/3358/.
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Business process management experiences a large uptake by the industry, and process models play an important role in the analysis and improvement of processes. While an increasing number of staff becomes involved in actual modeling practice, it is crucial to assure model quality and homogeneity along with providing suitable aids for creating models. In this paper we consider the problem of offering recommendations to the user during the act of modeling. Our key contribution is a concept for defining and identifying so-called action patterns - chunks of actions often appearing together in business processes. In particular, we specify action patterns and demonstrate how they can be identified from existing process model repositories using association rule mining techniques. Action patterns can then be used to suggest additional actions for a process model. Our approach is challenged by applying it to the collection of process models from the SAP Reference Model.Die zunehmende Bedeutung des Geschäftsprozessmanagements führt dazu, dass eine steigende Anzahl von Mitarbeitern eines Unternehmens mit der Erstellung von Prozessmodellen betraut ist. Um trotz dieser Tendenz die Qualität der Prozessmodelle, sowie ihre Homogenität sicherzustellen, sind entsprechende Modellierungshilfen unabdingbar. In diesem Bericht stellen wir einen Ansatz vor, welcher die Prozessmodellierung durch Empfehlungen unterstützt. Jene basieren auf sogenannten Aktionsmustern, welche typische Arbeitsblöcke darstellen. Neben der Definition dieser Aktionsmuster zeigen wir eine Methode zur Identifikation dieser Muster auf. Mittels Techniken der Assoziationsanalyse können die Muster automatisch aus einer Sammlung von Prozessmodellen extrahiert werden. Die Anwendbarkeit unseres Ansatzes wird durch eine Fallstudie auf Basis des SAP Referenzmodells illustriert.
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Salam, Hanan. "Modélisation Multi-Objet du visage." Phd thesis, Université Rennes 1, 2013. http://tel.archives-ouvertes.fr/tel-00957812.
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Cette thèse traite la problématique liée à la modélisation du visage dans le but de l'analyse faciale. Dans la première partie de cette thèse, nous avons proposé le Modèle Actif d'Apparence Multi-Objet. La spécificité du modèle proposé est que les différentes parties du visage sont traités comme des objets distincts et les mouvements oculaires (du regard et clignotement) sont extrinsèquement paramétrées. La deuxième partie de la thèse porte sur l'utilisation de la modélisation de visage dans le contexte de la reconnaissance des émotions. Premièrement, nous avons proposé un système de reconnaissance des expressions faciales sous la forme d'Action Units. Notre contribution porte principalement sur l'extraction des descripteurs de visage. Pour cela nous avons utilisé les modèles AAM locaux. Le second système concerne la reconnaissance multimodale des quatre dimensions affectives :. Nous avons proposé un système qui fusionne des caractéristiques audio, contextuelles et visuelles pour donner en sortie les quatre dimensions émotionnelles. Nous contribuons à ce système en trouvant une localisation précise des traits du visage. En conséquence, nous proposons l'AAM Multi-Modèle. Ce modèle combine un modèle global extrinsèque du visage et un modèle local de la bouche.
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Lin, Chu-chung. "The design of a distributed debugger for action-based object-oriented programs." Diss., Georgia Institute of Technology, 1987. http://hdl.handle.net/1853/8205.
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Baccouche, Moez. "Apprentissage neuronal de caractéristiques spatio-temporelles pour la classification automatique de séquences vidéo." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00932662.
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Cette thèse s'intéresse à la problématique de la classification automatique des séquences vidéo. L'idée est de se démarquer de la méthodologie dominante qui se base sur l'utilisation de caractéristiques conçues manuellement, et de proposer des modèles qui soient les plus génériques possibles et indépendants du domaine. Ceci est fait en automatisant la phase d'extraction des caractéristiques, qui sont dans notre cas générées par apprentissage à partir d'exemples, sans aucune connaissance a priori. Nous nous appuyons pour ce faire sur des travaux existants sur les modèles neuronaux pour la reconnaissance d'objets dans les images fixes, et nous étudions leur extension au cas de la vidéo. Plus concrètement, nous proposons deux modèles d'apprentissage des caractéristiques spatio-temporelles pour la classification vidéo : (i) Un modèle d'apprentissage supervisé profond, qui peut être vu comme une extension des modèles ConvNets au cas de la vidéo, et (ii) Un modèle d'apprentissage non supervisé, qui se base sur un schéma d'auto-encodage, et sur une représentation parcimonieuse sur-complète des données. Outre les originalités liées à chacune de ces deux approches, une contribution supplémentaire de cette thèse est une étude comparative entre plusieurs modèles de classification de séquences parmi les plus populaires de l'état de l'art. Cette étude a été réalisée en se basant sur des caractéristiques manuelles adaptées à la problématique de la reconnaissance d'actions dans les vidéos de football. Ceci a permis d'identifier le modèle de classification le plus performant (un réseau de neurone récurrent bidirectionnel à longue mémoire à court-terme -BLSTM-), et de justifier son utilisation pour le reste des expérimentations. Enfin, afin de valider la généricité des deux modèles proposés, ceux-ci ont été évalués sur deux problématiques différentes, à savoir la reconnaissance d'actions humaines (sur la base KTH), et la reconnaissance d'expressions faciales (sur la base GEMEP-FERA). L'étude des résultats a permis de valider les approches, et de montrer qu'elles obtiennent des performances parmi les meilleures de l'état de l'art (avec 95,83% de bonne reconnaissance pour la base KTH, et 87,57% pour la base GEMEP-FERA).
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Kelso, Janet. "The development and application of informatics-based systems for the analysis of the human transcriptome." Thesis, University of the Western Cape, 2003. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_5101_1185442672.
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Despite the fact that the sequence of the human genome is now complete it has become clear that the elucidation of the transcriptome is more complicated than previously expected. There is mounting evidence for unexpected and previously underestimated phenomena such as alternative splicing in the transcriptome. As a result, the identification of novel transcripts arising from the genome continues. Furthermore, as the volume of transcript data grows it is becoming increasingly difficult to integrate expression information which is from different sources, is stored in disparate locations, and is described using differing terminologies. Determining the function of translated transcripts also remains a complex task. Information about the expression profile &ndash
the location and timing of transcript expression &ndash
provides evidence that can be used in understanding the role of the expressed transcript in the organ or tissue under study, or in developmental pathways or disease phenotype observed.
In this dissertation I present novel computational approaches with direct biological applications to two distinct but increasingly important areas of research in gene expression research. The first addresses detection and characterisation of alternatively spliced transcripts. The second is the construction of an hierarchical controlled vocabulary for gene expression data and the annotation of expression libraries with controlled terms from the hierarchies. In the final chapter the biological questions that can be approached, and the discoveries that can be made using these systems are illustrated with a view to demonstrating how the application of informatics can both enable and accelerate biological insight into the human transcriptome.
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Lau, Johnny King Lam. "The neural basis of object perception : dissociating action and semantic processing." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6811/.
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This thesis has evaluated the roles of dorsal and ventral processing streams in recognition and use of objects. Four main empirical studies are presented. First, to investigate how the cortical brain processes semantic and action knowledge in different object-related tasks, I examined structural data from stroke patients (Chapter 2) and functional data from healthy individuals (Chapter 3) using a voxel-wise statistical analysis method. Using data of different modalities (structural CT, fMRI) from different sources (patients’ lesions; healthy subjects’ functional activity) handled with a systematic analysis approach, I attempted to find convergent evidence to support the dissociation of semantic and action processing. Second, I also looked into the potential differentiation within the mechanisms underlying object-related action (Chapter 4) and object naming (Chapter 5) separately. Overall, comparable findings were provided from the voxel-based morphometric analysis of patients’ lesion data and the fMRI study with healthy participants: an association was observed between ventral brain structures and the retrieval of semantic knowledge/object recognition while a dorsal fronto-parietal-occipital network was found to support the processing of action knowledge/object-oriented action. Specific dissociations were also observed within the representations for object-oriented actions as well as the mechanisms underlying naming of objects.
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Greening, Sarah Jane. "An information processing approach to the performance of perceptually guided action." Thesis, University of Surrey, 1994. http://epubs.surrey.ac.uk/843037/.
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The series of experiments reported in this thesis concern the ability to make perceptual-motor judgements of distance (Ex. 1 to Ex. 7) and size (Ex. 8). Experiments 1 and 2 indicated that visual judgements of maximum step length were effected by; distance from the site of action, the angle at which the obstacle was presented and whether monocular or binocular vision was used. This suggested that perceived maximum ability was not based on a body scaled invariant as suggested by Gibson (1979). Experiments 3 and 4 were designed to investigate the effect of altering the length of distance to-be-remembered, and compared performance across both visual and kinaesthetic conditions. The results suggested that the reproduction of distance is normally based on memory for the location of the end point, rather than the extent of the distance. No support was found for the claim that differences between the accuracy of recall of location and extent was due to the differential rehearsability of visual and kinaesthetic codes. Instead, it was proposed that changes in the procedure may have influenced performance by reducing the usefulness of a 'landmark' based form of coding in the extent trials. Experiments 5 and 6 were designed to investigate predictions arising from one of the dominant models of cross-modal performance (Connolly and Jones, 1970). Connolly and Jones's model postulated that differences between intra- and cross-modal performance could be explained in terms of the characteristics of modality specific short-term storage codes, and that translation between codes occurs prior to short-term storage. In general the results obtained were supportive of the pattern of accuracy reported by Connolly and Jones. However, the effect of delaying until the end of the retention interval knowledge of the reproduction mode was inconsistent with the model, that is, withholding information about the required reproduction mode appeared to increase the accuracy of judgements. One explanation for this effect is that pre-translated information was held in a form which was associated with high levels of both accuracy and attention. This speculative explanation was seen to have parallels with the Working Memory model (Baddeley and Hitch, 1974). Experiments 7 and 8 used an interference task paradigm to investigate whether a separate visuo-spatial store could be demonstrated to exist in relation to perceptual-motor information. The results failed to find conclusive support for such a store. The cumulative findings of Experiments 1 to 8 are discussed in relation general models of perceptual-motor performance.
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Jaber, Fadi. "Action potential recoording and processing from geometrically defined in-vitro neural networks." Thesis, University of Surrey, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.502671.
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Stafford, Tom. "Integrating psychological and neuroscientific constraints in models of Stroop processing and action selection." Thesis, University of Sheffield, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289618.
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Cressman, Erin K. "How do "invisible" stimuli influence action? : Visuomotor processing in the absence of conscious awareness." Thesis, University of British Columbia, 2007. http://hdl.handle.net/2429/31278.
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The goal of the current research was to examine the properties of visuomotor processing occurring in the absence of conscious awareness. Specifically, we investigated the ability of a subliminal stimulus to influence the on-line control of an action (Studies 1 and 2) and the extent to which the same subliminal stimulus could influence action when the probability of it predicting the upcoming response was manipulated (Studies 3 and 4). In order to display stimuli subliminally, stimuli were presented through the psychophysical procedure of metacontrast masking - a form of backward masking in which the visibility of a briefly displayed visual stimulus (the prime ) is greatly reduced when it is followed by a second visual stimulus (the mask ). Thus in the present research we were interested in how the primes would influence performance. Results revealed that (1) unconscious visuomotor processing can result in the modification of an overt response, such that a goal-directed movement is adjusted in response to a subliminal stimulus and (2) the visuomotor system can be modified in response to manipulations of the prime-mask sequence presented at an unconscious level. These results imply that subliminal stimuli are not processed in a conditionally automatic manner. In order to explain the ability of subliminal stimuli to influence behaviour we propose an accumulator model, in which adaptations to the state of the system arising due to task constraints are reflected at the level of response activation (i.e. at the accumulators). An "accumulator" is tuned to a specific stimulus-response mapping such that if participants are instructed to make a left or right response, two separate accumulators are established with one collecting neural evidence for stimuli mapped to the left response and the other collecting neural evidence for stimuli mapped to the right response. Both primes and masks are equally effective at driving the accumulators and a response is initiated as soon as the accumulated neural evidence for one response versus the alternative response reaches a critical threshold. The level of this threshold can be set strategically, or modified without awareness, depending on the prime-mask sequence displayed.Education, Faculty of
Kinesiology, School of
Graduate
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Radlbeck, Andrew J. "Machine Learning Based Action Recognition to Understand Distracted Driving." Digital WPI, 2019. https://digitalcommons.wpi.edu/etd-theses/1337.
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The ability to look outward from your vehicle and assess dangerous peer behavior is typically a trivial task for humans, but not always. Distracted driving is an issue that has been seen on our roadways ever since cars have been invented, but even more so after the wide spread use of cell phones. This thesis introduces a new system for monitoring the surrounding vehicles with outside facing cameras that detect in real time if the vehicle being followed is engaging in distracted behavior. This system uses techniques from image processing, signal processing, and machine learning. It’s ability to pick out drivers with dangerous behavior is shown to be accurate with a hit count of 87.5%, and with few false positives. It aims to help make either the human driver or the machine driver more aware and assist with better decision making.
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Araya, Jose Manuel. "Emotion and predictive processing : emotions as perceptions?" Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/33156.
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In this Thesis, I systematize, clarify, and expand the current theory of emotion based on the principles of predictive processing-the interoceptive inference view of emotion-so as to show the following: (1) as it stands, this view is problematic. (2) Once expanded, the view in question can deal with its more pressing problems, and it compares favourably to competing accounts. Thus, the interoceptive inference view of emotion stands out as a plausible theory of emotion. According to the predictive processing (PP) framework, all what the brain does, in all its functions, is to minimize its precision-weighted prediction error (PE) (Clark, 2013, 2016; Hohwy, 2013). Roughly, PE consist in the difference between the sensory signals expected (and generated) from the top-down and the actual, incoming sensory signals. Now, in the PP framework, visual percepts are formed by minimizing visual PE in a specific manner: via visual perceptual inference. That is, the brain forms visual percepts in a top-down fashion by predicting its incoming lower-level sensory signals from higher-level models of the likely (hidden) causes of those visual signals. Such models can be seen as putting forward content-specifying hypotheses about the object or event responsible for triggering incoming sensory activity. A contentful percept is formed once a certain hypothesis achieves to successfully match, and thus supress, current lower-level sensory signals. In the interoceptive inference approach to interoception (Seth, 2013, 2015), the principles of PP have been extended to account for interoception, i.e., the perception of our homeostatic, physiological condition. Just as perception in the visual domain arises via visual perceptual inference, the interoceptive inference approach holds that perception of the inner, physiological milieu arises via interoceptive perceptual inference. Now, what might be called the interoceptive inference theory of valence (ITV) holds that the interoceptive inference approach can be used so as to account for subjective feeling states in general, i.e., mental states that feel good or bad-i.e., valenced mental states. According to ITV, affective valence arises by way of interoceptive perceptual inference. On the other hand, what might be called the interoceptive inference view of emotion (IIE) holds that the interoceptive inference approach can be used so as to account for emotions per se (e.g., fear, anger, joy). More precisely, IIE holds that, in direct analogy to the way in which visual percepts are formed, emotions arise from interoceptive predictions of the causes of current interoceptive afferents. In other words, emotions per se amount to interceptive percepts formed via higher-level, content-specifying emotion hypotheses. In this Thesis, I aim to systematize, clarify, and expand the interoceptive inference approach to interoception, in order to show that: (1) contrary to non-sensory theories of affective valence, valence is indeed constituted by interoceptive perceptions, and that interoceptive percepts do arise via interoceptive perceptual inference. Therefore, ITV holds. (2) Considering that IIE exhibits problematic assumptions, it should be amended. In this respect, I will argue that emotions do not arise via interoceptive perceptual inference (as IIE claims), since this assumes that there must be regularities pertaining to emotion in the physiological domain. I will suggest that emotions arise instead by minimizing interoceptive PE in another fashion. That is, emotions arise via external interoceptive active inference: by sampling and modifying the external environment in order to change an already formed interoceptive percept (which has been formed via interoceptive perceptual inference). That is, emotions are specific strategies for regulating affective valence. More precisely, I will defend the view that a certain emotion E amounts to a specific strategy for minimizing interoceptive PE by way of a specific set of stored knowledge of the counterfactual relations that obtain between (possible) actions and its prospective interoceptive, sensory consequences ("if I act in this manner, interoceptive signals should evolve in such-and-such way"). An emotion arises when such knowledge is applied in order to regulate valence.
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Linden, Dimitri van der. "Mental fatigue and goal-directed behavior: flexibility, planning and the regulation of actions." [S.l. : Amsterdam : Kurt Lewin Instituut] ; Universiteit van Amsterdam [Host], 2002. http://dare.uva.nl/document/64093.
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Song, Haitao. "Information management in the travel industry: The role and impact of the Internet." Thesis, University of the Western Cape, 2005. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=init_6662_1178282746.
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In this information age, the Internet has found a role in various industries such as transportation, advertising, etc. The travel industry, in which communication between travellers and travel service providers is a very important component, has as much potential as any other industry to make full use of this new medium. Already, most travel agencies and travel service providers promote their products and services using web sites. Searching for information online is now seen by many people as a way to save time and cost, especially in their travel activities. In order to fully deploy the Internet within the travel industry, understanding the use of the Internet in tourism is critical. This research sets out initially to examine the role and the impact of the Internet in the whole of the travel industry. But in order to define an achievable scope of work and because of its importance in South Africa at this time, tourism within the travel industry was chosen as the focus of the work.
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Smimmo, Luigi. "Micro-affordances during lexical processing : considerations on the nature of object-knowledge representations." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/23416.
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Micro-affordance effects have been reported for several different components of the reach-to-grasp action during both on-line and off-line visual processing. The presence of such effects represents a strong demonstration of the close relationship between perception, action, and cognition. In this thesis 7 experiments are described, which investigate different aspects of that relationship, with particular attention on the nature of object representations. In 5 behavioural experiments as well as in 1 Transcranial Magnetic Stimulation (TMS) experiment a stimulus-response compatibility paradigm is employed to examine the presence of micro-affordance effects arising during language processing of object names. The power and precision component of the reach-to-grasp action is investigated in relation to the compatibility of an object for grasping with either a power or a precision grasp. Overall, the results of the experiments discussed in the present thesis suggest that: a) object representations activated during language processing of object names are able to potentiate actions arising from the component of the reach-to-grasp action under investigation; b) such representations might be more semantic or „propositional‟ than depictive in nature, therefore more related to stored semantic knowledge of the object and its associated actions than to its detailed visual properties; c) this semantic information about objects seems to be automatically translated into specific motor activity, even in the absence of any intention to act; d) finally, such semantic, non-visual motor potentiation seems to be rapid and relatively short lived.
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Ladwig, Stefan [Verfasser]. "About multimodal information processing and the relation of proximal and distal action effects / Stefan Ladwig." Aachen : Hochschulbibliothek der Rheinisch-Westfälischen Technischen Hochschule Aachen, 2015. http://d-nb.info/1066812535/34.
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Janse, Van Vuuren Michaella. "Human Pose and Action Recognition using Negative Space Analysis." Diss., University of Cape Town, 2004. http://hdl.handle.net/10919/71571.
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This thesis proposes a novel approach to extracting pose information from image sequences. Current state of the art techniques focus exclusively on the image space occupied by the body for pose and action recognition. The method proposed here, however, focuses on the negative spaces: the areas surrounding the individual. This has resulted in the colour-coded negative space approach, an image preprocessing step that circumvents the need for complicated model fitting or template matching methods. The approach can be described as follows: negative spaces surrounding the human silhouette are extracted using horizontal and vertical scanning processes. These negative space areas are more numerous, and undergo more radical changes in shape than the single area occupied by the figure of the person performing an action. The colour-coded negative space representation is formed using the four binary images produced by the scanning processes. Features are then extracted from the colour-coded images. These are based on the percentage of area occupied by distinct coloured regions as well as the bounding box proportions. Pose clusters are identified using feedback from an independent action set. Subsequent images are classified using a simple Euclidean distance measure. An image sequence is thus temporally segmented into its corresponding pose representations. Action recognition simply becomes the detection of a temporally ordered sequence of poses that characterises the action. The method is purely vision-based, utilising monocular images with no need for body markers or special clothing. Two datasets were constructed using several actors performing different poses and actions. Some of these actions included actors waving their arms, sitting down or kicking a leg. These actions were recorded against a monochrome background to simplify the segmentation of the actors from the background. The actions were then recorded on DV cam and digitised into a data base. The silhouette images from these actions were isolated and placed in a frame or bounding box. The next step was to highlight the negative spaces using a directional scanning method. This scanning method colour-codes the negative spaces of each action. What became immediately apparent is that very distinctive colour patterns formed for different actions. To emphasise the action, different colours were allocated to negative spaces surrounding the image. For example, the space between the legs of an actor standing in a T - pose with legs apart would be allocated yellow, while the space below the arms were allocated different shades of green. The space surrounding the head would be different shades of purple. During an action when the actor moves one leg up in a kicking fashion, the yellow colour would increase. Inversely, when the actor closes his legs and puts them together, the yellow colour filling the negative space would decrease substantially. What also became apparent is that these coloured negative spaces are interdependent and that they influence each other during the course of an action. For example, when an actor lifts one of his legs, increasing the yellow-coded negative space, the green space between that leg and the arm decreases. This interrelationship between colours hold true for all poses and actions as presented in this thesis. In terms of pose recognition, it is significant that these colour coded negative spaces and the way the change during an action or a movement are substantial and instantly recognisable. Compare for example, looking at someone lifting an arm as opposed to seeing a vast negative space changing shape. In a controlled research environment, several actors were instructed to perform a number of different actions. After colour coding the negative spaces, it became apparent that every action can be recognised by a unique colour coded pattern. The challenge is to ascribe a numerical presentation, a mathematical quotation, to extract the essence of what is so visually apparent. The essence of pose recognition and it's measurability lies in the relationship between the colours in these negative spaces and how they impact on each other during a pose or an action. The simplest way of measuring this relationship is by calculating the percentage of each colour present during an action. These calculated percentages become the basis of pose and action recognition. By plotting these percentages on a graph confirms that the essence of these different actions and poses can in fact been captured and recognised. Despite variations in these traces caused by time differences, personal appearance and mannerisms, what emerged is a clear recognisable pattern that can be married to an action or different parts of an action. 7 Actors might lift their left leg, some slightly higher than others, some slower than others and these variations in terms of colour percentages would be recorded as a trace, but there would be very specific stages during the action where the traces would correspond, making the action recognisable.In conclusion, using negative space as a tool in human pose and tracking recognition presents an exiting research avenue because it is influenced less by variations such as difference in personal appearance and changes in the angle of observation. This approach is also simplistic and does not rely on complicated models and templates
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Siluyele, Ian John. "Power studies of multivariate two-sample tests of comparison." Thesis, University of the Western Cape, 2007. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_6355_1255091702.
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The multivariate two-sample tests provide a means to test the match between two multivariate distributions. Although many tests exist in the literature, relatively little is known about the relative power of these procedures. The studies reported in the thesis contrasts the effectiveness, in terms of power, of seven such tests with a Monte Carlo study. The relative power of the tests was investigated against location, scale, and correlation alternatives.
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Dufort, Paul Anthony. "Computational modeling of nucleotide processing by the actin cytoskeleton regulatory network." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0022/NQ49953.pdf.
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Boardman, Anelda Philine. "Assessment of genome visualization tools relevant to HIV genome research: development of a genome browser prototype." Thesis, University of the Western Cape, 2004. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=gen8Srv25Nme4_3632_1185446929.
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Over the past two decades of HIV research, effective vaccine candidates have been elusive. Traditionally viral research has been characterized by a gene -by-gene approach, but in the light of the availability of complete genome sequences and the tractable size of the HIV genome, a genomic approach may improve insight into the biology and epidemiology of this virus. A genomic approach to finding HIV vaccine candidates can be facilitated by the use of genome sequence visualization. Genome browsers have been used extensively by various groups to shed light on the biology and evolution of several organisms including human, mouse, rat, Drosophila and C.elegans. Application of a genome browser to HIV genomes and related annotations can yield insight into forces that drive evolution, identify highly conserved regions as well as regions that yields a strong immune response in patients, and track mutations that appear over the course of infection. Access to graphical representations of such information is bound to support the search for effective HIV vaccine candidates. This study aimed to answer the question of whether a tool or application exists that can be modified to be used as a platform for development of an HIV visualization application and to assess the viability of such an implementation. Existing applications can only be assessed for their suitability as a basis for development of an HIV genome browser once a well-defined set of assessment criteria has been compiled.
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Freier, Livia. "The development of bottom-up and top-down interaction in the processing of goal-directed action." Thesis, Birkbeck (University of London), 2016. http://bbktheses.da.ulcc.ac.uk/176/.
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The study of action-cognition is driven by the assumption that what one can do motorically depends on what one can conceive of mentally, given a set of external opportunities (Rosenbaum, Cohen, & Jax, 2007). Therefore, a comprehensive theory of action development ought to integrate perceptual aspects of action processing with conceptual changes that give rise to increasingly abstract behaviours. How and why children progress to higher levels of organization in the processing and coordination of purposeful behaviour is a question that has been at the core of developmental research for decades. Various competences underlying early action processing and decision-making have been identified and linked to sophisticated mental operations later in life. However, considerably less is known about the relationships between perceptual and conceptual abilities and how they interact to shape action development. Goal-pursuit is achieved with increasing efficiency during the preschool period. In fact, by the age of first grade children show substantial abilities to regulate actions into hierarchically structured sequences of events that can be transferred across contexts (e.g., Levy, 1980; Bell & Livesey, 1985; Livesey & Morgan, 1991). The aim of this project was to investigate the perceptual and conceptual processes that drive these remarkable advances as they emerge during the preschool years. The studies in this thesis investigate top-down and bottom-up interactions in the processing of actions at various levels of abstraction. Employing a range of novel paradigms, the results of four studies highlight considerable advances in preschoolers’ abilities to organise actions in terms of goal hierarchies. Findings further highlight that the ability to extract structure at a basic level is readily achieved early in life, while higher-level action comprehension and planning abilities continue to develop throughout the childhood years.
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Pérez, Masiá Rocío. "MICRO- AND NANOENCAPSULATION VIA ELECTRO-HYDRODYNAMIC PROCESSING OF INTEREST IN FOOD APPLICATIONS." Doctoral thesis, Universitat Politècnica de València, 2014. http://hdl.handle.net/10251/39341.
Full textAbstract:
Micro- and nanoencapsulation have generated great interest over the last
years in multiple fields. Particularly in the food industry, this technology
presents potential applications for the development of smart packaging
structures, as well as for the protection of sensitive ingredients and the
production of novel healthy foods. Therefore, in this thesis, the
development of different encapsulation structures of interest in the food
area was carried out. Specifically, capsules were obtained through
electrohydrodynamic processing, since this technology presents several
advantages over other well-established encapsulation technologies. For
instance, it does not require the use of high temperatures and
encapsulation structures from some biopolymers can be attained by using
aqueous solutions.
Initially, microencapsulation for smart packaging applications was
investigated. In this area novel heat management packaging structures
were obtained through the encapsulation of phase change materials
(PCMs) within different polymeric matrices. The morphology, thermal
properties, molecular organization and thermal energy storage ability of
these capsules were evaluated.
Afterwards, the encapsulation of bioactive ingredients for functional food
applications was studied. In this field, novel micro- and nanoencapsulation
structures were initially obtained through electrospraying from food
contact materials. Finally, a vitamin and an antioxidant were encapsulated
within different hydrocolloid matrices through electrospraying. Capsules
attained were characterized and compared to those obtained through
other encapsulation techniques. Moreover, stability of the encapsulated
bioactives was studied under adverse conditions.Pérez Masiá, R. (2014). MICRO- AND NANOENCAPSULATION VIA ELECTRO-HYDRODYNAMIC PROCESSING OF INTEREST IN FOOD APPLICATIONS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/39341
TESIS
Premiado
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Buc, Calderon Cristian. "Temporal dynamics and neural architecture of action selection." Doctoral thesis, Universite Libre de Bruxelles, 2016. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/229408.
Full textAbstract:
In this thesis we pitted two views of action selection. On the one hand, a traditional view suggesting that action selection emerges from a sequential process whereby perception, cognition and action proceed serially and are subtended by distinct brain areas. On the other hand, an ecological view (formalized in the affordance competition hypothesis) advocating that action selection stems from the parallel implementation of potential action plans. In parallel, the competition between these action plans would be biased by relevant task factors. We first addressed the issue of the temporal dynamics of action selection processes in Chapter 2. We built a reaching task design that crucially gave equal opportunities for serial and parallel processing of cognitive and motor processes to occur. In our study, we first cued participants with probabilities associated to upcoming potential reaches. After several hundreds of milliseconds, participants were given a deterministic go signal indicating which target to reach for. They had to reach for the signaled target as fast as possible. Importantly, our design tries to cope with the biases involved in previous reaching tasks, allowing for a much more informative way to tackle the issue of serial versus parallel processing in action selection. We show that effects of action probability are not only present in the initiation time (i.e. the time it takes to initiate the movement), but crucially also in the movement time (i.e. the time interval between movement initiation and target reaching). Furthermore, an analysis of the movement trajectories showed that reach probability influenced the trajectories according to the predicted pattern. Thus, these results back up a system where cognitive and motor processes continuously interact with one another to come up with a decision. After clarifying the temporal dynamics, we concentrate our efforts on exposing the neural architecture of processes subtending action selection in Chapter 3. In a two-choice button press task, participants were first cued with predictive information regarding upcoming button presses. Crucially, we experimentally manipulated the amount of information in favor of specific button presses whilst adopting a design as similar as possible to those used in monkey neurophysiology (e.g. Cisek & Kalaska, 2005). Using fMRI, our results showed that as information in favor a button press increases, so does activity in the contralateral primary motor cortex, while activity in the ipsilateral primary motor cortex decreases. Moreover, we observed that primary motor regions are more tightly coupled with fronto-parietal areas in a condition involving a decision compared with a situation not implicating a decision between two button presses. Our results are compatible with an account predicting that decision-making emerges from motor areas, and therefore suggest that the architecture presented in the affordance competition hypothesis is not only valid in monkeys but also humans. In Chapter 4, we combine the findings acquired in the studies of chapter 2 and 3 with recent neurophysiological insights to develop a neuro-computational model capable of grasping the continuous interaction between cognitive and motor processes, responsible for the behavioral pattern in reach selection tasks. Our model functions on the principles of cascade forward models whereby activation at one stage of processing systematically spills to the next one, thereby substantially blurring the boundaries between perceptive, cognitive and motor processes. Contrary to most computational models confining action selection processes prior to action execution, our model allows for these processes to leak into action execution. Moreover, the threshold for action execution is not fixed, but rather dynamic and crucially depends on the activity pattern of the model’s primary motor neurons. We propose that the modification of the threshold is governed by the subthalamic nucleus, receiving direct input signals from the primary motor cortex and in turn imposing a dynamical brake on action execution. By including this dynamical threshold, our model has the advantage that it can release movement execution either rapidly or slowly depending on the context. Our model accounts not only for initiation times, but also movement times in reaching task studies. Furthermore, it can grasp the qualitative pattern of movement trajectories. This study suggests that to explain unfolding actions a classical fixed threshold is not sufficient, but rather an execution threshold level that is continuously being updated depending on the context is required.Doctorat en Sciences psychologiques et de l'éducation
info:eu-repo/semantics/nonPublished
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Scheffler, Carl. "Articulated structure from motion." Thesis, University of the Western Cape, 2004. http://etd.uwc.ac.za/index.php?module=etd&action=viewtitle&id=init_2988_1177923873.
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The structure from motion (SfM) problem is that of determining 3-dimensional (3D) information of a scene from sequences of 2-dimensional (2D) images [59]. This information consists of object shape and motion and relative camera motion. In general, objects may undergo complex non-rigid motion and may be occluded by other objects or themselves. These aspects make the general SfM problem under-constrained and the solution subject to missing or incomplete data.
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Aceto, Luca. "Action refinement in process algebras /." Cambridge ; New York, NY, USA : Cambridge University Press, 1992. http://www.loc.gov/catdir/toc/cam029/92249890.html.
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Pacini, Adele Marie. "Determining the contribution of embodiment in the cognitive processing of affect, meaning, and the control of action." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.611125.
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Cartas, Ayala Alejandro. "Recognizing Action and Activities from Egocentric Images." Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/670752.
Full textAbstract:
Egocentric action recognition consists in determining what a wearable camera user is
doing from his perspective. Its defining characteristic is that the person himself is only
partially visible in the images through his hands. As a result, the recognition of actions
can rely solely on user interactions with objects, other people, and the scene. Egocentric action recognition has numerous assistive technology applications, in particular in the field of rehabilitation and preventive medicine. The type of egocentric camera determines the activities or actions that can be predicted. There are roughly two kinds: lifelogging and video cameras. The former can continuously take pictures every 20-30 seconds during day-long periods. The sequences of pictures produced by them are called visual lifelogs or photo-streams. In comparison with video, they lack of motion that typically has been used to disambiguate actions. We present several egocentric action recognition approaches for both settings.
We first introduce an approach that classifies still-images from lifelogs by combining a convolutional network and a random forest. Since lifelogs show temporal coherence within consecutive images, we also present two architectures that are based on the long short-term memory (LSTM) network. In order to thoroughly measure their generalization performance, we introduce the largest photo-streams dataset for activity recognition. These tests not only consider hidden days and multiple users but also the effect of time boundaries from events. We finally present domain adaptation strategies for dealing with unknown domain images in a real-world scenario.
Our work on egocentric action recognition from videos is primarily focused on object-interactions. We present a deep network that in the first level models person to-object interactions, and in the second level models sequences of actions as part of a single activity. The spatial relationship between hands and objects is modeled using a region-based network, whereas the actions and activities are modeled using a hierarchical LSTM. Our last approach explores the importance of audio produced by the egocentric manipulations of objects. It combines a sparse temporal sampling strategy with a late fusion of audio, RGB, and temporal streams. Experimental results on the EPIC-Kitchen dataset show that multimodal integration leads to better performance than unimodal approaches.El reconeixement d’accions egocèntriques consisteix a determinar què fa un usuari de càmera egocèntrica des de la seva perspectiva. La característica fonamental que defineix aquesta tasca és que la persona mateixa només és parcialment visible: a les imatges només veurem les seves mans. Com a resultat, el reconeixement d’accions pot dependre únicament de les interaccions dels usuaris amb objectes, altres persones i l’escena mitjançant les seves mans. El reconeixement d’acció egocèntrica té nombroses aplicacions tecnològiques d’assistència, en particular en el camp de la rehabilitació i la medicina preventiva. El tipus de càmera egocèntrica determina les activitats o les accions que es poden predir. Hi ha, grosso modo, dos tipus: registre de vida i càmeres de vídeo. Les càmeres de registre de vida poden prendre fotografies cada 20-30 segons de manera continuada durant tot el dia. Les seqüències d'imatges produïdes per aquestes s'anomenen visual lifelogs o photo-streams. En comparació amb el vídeo, manquen de moviment, el qual normalment es fa servir per desambiguar les accions. Presentem múltiples propostes per a reconeixement d’acció egocèntrica en ambdós contextos. Primer introduïm una proposta per classificar les imatges fixes dels registres de vida combinant una xarxa convolucional i un random forest. Com que els registres de vida mostren coherència temporal en imatges consecutives, també presentem dues arquitectures basades en una xarxa de long short-term memory (LSTM). Per mesurar a fons el seu rendiment de generalització, presentem la base de dades més gran de seqüències de fotos per al reconeixement d’activitats. Aquestes proves no només tenen en compte els dies ocults i diversos usuaris, sinó també l’efecte de les fronteres temporals dels diferents esdeveniments. Finalment presentem estratègies d’adaptació de dominis per tractar imatges de domini desconegut en un escenari del món real. El nostre treball sobre el reconeixement d’accions egocèntriques a partir de vídeos se centra principalment en les interaccions amb objectes. Presentem una xarxa profunda que en el primer nivell modela les interaccions entre persona i objecte i en el segon nivell modela les seqüències d’accions com a part d’una única activitat. La relació espacial entre mans i objectes es modela mitjançant una xarxa basada en regions, mentre que les accions i activitats es modelen mitjançant una xarxa LSTM jeràrquica. La nostra darrera proposta explora la importància de l'àudio produït per les manipulacions egocèntriques d'objectes. Combina una estratègia de mostreig temporal escassa amb una fusió tardana d’àudio, RGB i fluxos temporals. Els resultats experimentals sobre la base de dades EPIC-Kitchen mostren que la integració multimodal resulta en un millor rendiment que els plantejaments unimodals.
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Moreira, Thierry Pinheiro 1990. "Real-time human action recognition based on motion shapes." [s.n.], 2014. http://repositorio.unicamp.br/jspui/handle/REPOSIP/275509.
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Orientador: Hélio PedriniDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Computação
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Resumo: Reconhecimento de ações humanas em vídeos é uma área de conhecimento em expansão. Há uma vasta gama de possíveis aplicações, incluindo interface de usuários, vigilância, casas inteligentes e monitoramento de saúde. A maioria delas requer respostas em tempo real. No entanto, há um equilíbrio entre tempo de processamento e eficácia do reconhecimento, sendo que eficácia compreende acurácia e robustez em múltiplas situações. Duas contribuições são apresentadas neste trabalho. A primeira é um método de obtenção de informação relevante de movimento em vídeos, mesmo usando uma subtração de fundo simples, por meio da união de uma janela deslizante de figuras. A segunda é um descritor simples e rápido, baseado em silhuetas ou, genericamente, em figuras de movimento, que alcança o estado da arte na acurácia em tempo real. Ele é construído a partir das posições relativas de pontos de interesse escolhidos como pontos extremos nas figuras de movimento. O método foi testado em três bases de dados públicas e os resultados experimentais são comparados com outros da literatura. Algumas bases possuem disponíveis silhuetas segmentadas manualmente, permitindo a análise de cada contribuição separadamente. Em todos os casos, as características foram extraídas em altas taxas de quadros por segundo
Abstract: Human action recognition in videos is an expanding area of knowledge. There is a wide range of possible applications, including user interface, surveillance, smart homes and health monitoring. Most of them require real time responses, however, there is a trade-off between processing time and effectiveness of the recognition, where effectiveness comprises accuracy and robustness in a number of situations. Two main contributions are presented in this work. The first one is a method for obtaining relevant motion information from videos, even by making use of poorly extracted foreground, by joining a temporal window of shapes. The second one is a simple and fast descriptor, based on silhouettes or, generically, on motion shapes, that achieves state-of-the-art accuracy in real time. It is built from the relative positions of interest points chosen as extreme points on the motion shapes. The method is tested on three public data sets and the experimental results are compared against others from the literature. Some data sets have manually segmented silhouettes available, allowing to analyze each contribution separately. In all cases, the features are extracted at high frame rates
Mestrado
Ciência da Computação
Mestre em Ciência da Computação
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Guo, Shuang [Verfasser]. "The Impact of Cognitive- and Action- Predictive Processes on Neural Correlates of Syntactic Processing in Music / Shuang Guo." Berlin : Freie Universität Berlin, 2017. http://d-nb.info/1136903658/34.
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Yip, Tin-hang James, and 葉天恒. "Object and action word processing in Chinese stroke patients with or without executive dysfunction: aneuropsychological case-control study." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44530808.
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Suyama, Hajime [Verfasser], and Veronica [Akademischer Betreuer] Egger. "Vasopressinergic action in the olfactory bulb: Substrates and impact on social odor processing / Hajime Suyama ; Betreuer: Veronica Egger." Regensburg : Universitätsbibliothek Regensburg, 2021. http://d-nb.info/1236401441/34.
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