Algoritmo de vergencia para o controle de atenção de humanos virtuais

Orientador: Luiz Marcos Garcia GonçalvesDissertação (mestrado) - Universidade Estadual de Campinas. Instituto de ComputaçãoResumo: Os problemas de pesquisa mais comuns abordados na literatura sobre Humanos Virtuais são mais relacionados com a inserção e representação destes agentes gráficos no computador. Com o avanço das tecnologias e pesquisas nas áreas de computação gráfica e realidade virtual, novos problemas podem ser tratados, em relação as funcionalidades destes agentes virtuais. Atualmente, um dos principais desafios está associado ao desenvolvimento de humanos virtuais dotados de percepção visual realística. Um problema específico, referente a visão sintética destes agentes, é o controle da atenção, ou seja, definir e prover uma maneira eficiente e natural para que ele mude seu foco de atenção de uma posição corrente para outra no seu ambiente virtual. A coordenação dos movimentos da cabeça do agente, fazendo com que os olhos sejam fixados no objeto desejado, não é considerada uma tarefa trivial e está relacionada com a percepção de profundidade do ambiente. Neste trabalho, propomos um algoritmo de vergência, usado para o controle da atenção de humanos virtuais, onde o parâmetro de profundidade é obtido do Z-buffer. O controle dos movimentos da cabeça do humano virtual é executado com a realização de simples cálculos geométricos e no final do processo de vergência, os olhos são fixados corretamente em qualquer região de interesse do ambiente, passada previamente para o agente virtualAbstract: Common research problems treated in literature about Virtual Humans are most related with insertion and representation of these graphic agents in computers. With techological advance and new researches in Computer Graphics and Virtual Reality, new problems can have place, related to the funcionality of the virtual agents. Currently, one of the main challenges is associated to development of virtual humans with realistic virtual perception and a specific problem that appears, related to synthetic vision in these agents, is the proper control of attention. That is, to define and provide an efficient and natural manner for it to change attentional focus from a current position to another one in its virtual environrnent. Coordination of head movements by way of fixation of eyes in a desired object is not considered a trivial task, being related to depth perception. In this work, we propose an algorithm for vergence, used for attention control in virtual humans, where the depth parameter is obtained from Z-buffer. Control of virtual human head movements is preformed with simple geometric calculations and at the end of vergence process the eyes are correctly fixed in any interest region of the environment, previously given to the virtual agentMestradoCiência da ComputaçãoMestre em Ciência da Computaçã

Data-driven constraint-based motion editing

The growth of motion capture systems has contributed to the proliferation of human motion database, mainly because human motion is important in many applications, ranging from games entertainment and films to sports and medicine. However, the various captured motions normally require specific needs. Consequently, modifying and reusing these motions in new situations – for example, retargeting it to a new environment – became an increasing area of research known as motion editing. In the last few years, human motion editing has become one of the most active research areas in the field of computer animation. In this thesis, we introduce and discuss a novel method for interactive human motion editing. Our main contribution is the development of a Low-dimensional Prioritized Inverse Kinematics (LPIK) technique that handles user constraints within a low-dimensional motion space – also known as the latent space. Its major feature is to operate in the latent space instead of the joint space. By construction, it is sufficient to constrain a single frame with LPIK to obtain a natural movement enforcing the intrinsic motion flow. The LPIK has the advantage of reducing the size of the Jacobian matrix as the motion latent space dimension is small for a coordinated movement compared to the joint space. Moreover, the method offers the compelling advantage that it is well suited for characters with large number of degrees of freedom (DoFs). This is one of the limitations of IK methods that perform optimizations in the joint space. In addition, our method still provides faster deformations and more natural-looking motion results compared to goal-directed constraint-based methods found in the literature. Essentially, our technique is based on the mathematical connections between linear motion models such as Principal Component Analysis (PCA) and Prioritized Inverse Kinematics (PIK). We use PCA as a first stage of preprocessing to reduce the dimensionality of the database to make it tractable and to encapsulate an underlying motion pattern. And after, to bound IK solutions within the space of natural-looking motions. We use PIK to allow the user to manipulate constraints with different priorities while interactively editing an animation. Essentially, the priority strategy ensures that a higher priority task is not affected by other tasks of lower priority. Furthermore, two strategies to impose motion continuity based on PCA are introduced. We show a number of experiments used to evaluate and validate (both qualitatively and quantitatively) the benefits of our method. Finally, we assess the quality of the edited animations against a goal-directed constraint-based technique, to verify the robustness of our method regarding performance, simplicity and realism

Progress from ASDEX Upgrade experiments in preparing the physics basis of ITER operation and DEMO scenario development

An overview of recent results obtained at the tokamak ASDEX Upgrade (AUG) is given. A work flow for predictive profile modelling of AUG discharges was established which is able to reproduce experimental H-mode plasma profiles based on engineering parameters only. In the plasma center, theoretical predictions on plasma current redistribution by a dynamo effect were confirmed experimentally. For core transport, the stabilizing effect of fast ion distributions on turbulent transport is shown to be important to explain the core isotope effect and improves the description of hollow low-Z impurity profiles. The L-H power threshold of hydrogen plasmas is not affected by small helium admixtures and it increases continuously from the deuterium to the hydrogen level when the hydrogen concentration is raised from 0 to 100%. One focus of recent campaigns was the search for a fusion relevant integrated plasma scenario without large edge localised modes (ELMs). Results from six different ELM-free confinement regimes are compared with respect to reactor relevance: ELM suppression by magnetic perturbation coils could be attributed to toroidally asymmetric turbulent fluctuations in the vicinity of the separatrix. Stable improved confinement mode plasma phases with a detached inner divertor were obtained using a feedback control of the plasma β. The enhanced D α H-mode regime was extended to higher heating power by feedback controlled radiative cooling with argon. The quasi-coherent exhaust regime was developed into an integrated scenario at high heating power and energy confinement, with a detached divertor and without large ELMs. Small ELMs close to the separatrix lead to peeling-ballooning stability and quasi continuous power exhaust. Helium beam density fluctuation measurements confirm that transport close to the separatrix is important to achieve the different ELM-free regimes. Based on separatrix plasma parameters and interchange-drift-Alfvén turbulence, an analytic model was derived that reproduces the experimentally found important operational boundaries of the density limit and between L- and H-mode confinement. Feedback control for the X-point radiator (XPR) position was established as an important element for divertor detachment control. Stable and detached ELM-free phases with H-mode confinement quality were obtained when the XPR was moved 10 cm above the X-point. Investigations of the plasma in the future flexible snow-flake divertor of AUG by means of first SOLPS-ITER simulations with drifts activated predict beneficial detachment properties and the activation of an additional strike point by the drifts

A multi-country test of brief reappraisal interventions on emotions during the COVID-19 pandemic.

The COVID-19 pandemic has increased negative emotions and decreased positive emotions globally. Left unchecked, these emotional changes might have a wide array of adverse impacts. To reduce negative emotions and increase positive emotions, we tested the effectiveness of reappraisal, an emotion-regulation strategy that modifies how one thinks about a situation. Participants from 87 countries and regions (n = 21,644) were randomly assigned to one of two brief reappraisal interventions (reconstrual or repurposing) or one of two control conditions (active or passive). Results revealed that both reappraisal interventions (vesus both control conditions) consistently reduced negative emotions and increased positive emotions across different measures. Reconstrual and repurposing interventions had similar effects. Importantly, planned exploratory analyses indicated that reappraisal interventions did not reduce intentions to practice preventive health behaviours. The findings demonstrate the viability of creating scalable, low-cost interventions for use around the world

Quantifying effects of stochasticity in reference frame transformations on posterior distributions

Reference frame transformations are usually considered to be deterministic. However, translations, scaling or rotation angles could be stochastic. Indeed, variability of these entities often originates from noisy estimation processes. The impact of transformation noise on the statistics of the transformed signals is unknown and a quantification of these effects is the goal of this study. We first quantify analytically and numerically how stochastic reference frame transformations alter the posterior distribution of the transformed signals. We then propose an new empirical measure to quantify deviations from a given distribution when only limited data is available. We apply this empirical measure to an example in sensory-motor neuroscience to quantify how different head roll angles change the distribution of reach endpoints away from the normal distribution

Teaching community of practice: permanent training strategy for teaching vocational training in nursing*

Objetivo: Identificar possibilidades para o desenvolvimento de Comunidade de Prática docente como estratégia de formação permanente para a docência na educação técnica em enfermagem. Método: Pesquisa qualitativa do tipo pesquisa-ação, realizada com professores do curso técnico em enfermagem e coordenação pedagógica de uma Escola Técnica do Sistema Único de Saúde do Ceará. Os dados foram coletados por grupos focais e submetidos à análise de conteúdo de Bardin, com suporte do Qualitative Data Analysis Software. Resultados: Possibilidades para o desenvolvimento de comunidade de prática docente foram identificadas mediante a percepção da necessidade de formação docente, dificuldade de conciliar trabalho e estudo e viabilidade de promover esta formação em grupo. Conclusão: A comunidade de prática docente, além de ser uma estratégia viável para a formação docente em enfermagem, é premente, pois a formação de trabalhadores de nível médio é determinante para a qualidade do cuidado e consolidação do Sistema Único de Saúde.Objective: To identify possibilities for developing teaching community of practice as a permanent training strategy for teaching in vocational nursing education. Method: This is a qualitative action research, carried out with vocational training professors and pedagogical coordination of a Unified Health System Vocational School of Ceará. Data were collected by focus groups and submitted to Bardin’s content analysis, supported by the Qualitative Data Analysis Software. Results: Possibilities for the development of teaching community of practice were identified by the perception of the need for teacher training, difficulty in reconciling work and study, and the feasibility of promoting this training in a group. Conclusion: Teaching community of practice, in addition to being a viable strategy for nursing professor education, is urgent, as the training of secondary-level workers is crucial for quality of care and consolidation of the Unified Health System.Objetivo: Identificar posibilidades para el desarrollo de una comunidad de práctica docente como estrategia de formación permanente para la docencia en educación técnica en enfermería. Método: Investigación cualitativa del tipo investigación-acción, realizada con profesores del curso técnico en enfermería y coordinación pedagógica de una Escuela Técnica del Sistema Único de Salud de Ceará. Los datos fueron recopilados por grupos focales y enviados al análisis de contenido de Bardin, con el apoyo del software de análisis de datos cualitativos. Resultados: Se identificaron posibilidades para el desarrollo de una comunidad de práctica docente a través de la percepción de la necesidad de formación docente, la dificultad para conciliar trabajo y estudio, y la viabilidad de promover esta formación en grupos. Conclusión: La comunidad de práctica docente, además de ser una estrategia viable para la formación del profesorado de enfermería, es urgente, pues la formación de los trabajadores del nivel secundario es fundamental para la calidad de la atención y la consolidación del Sistema Único de Salud