Tiago Cardoso

Human-Computer-Interaction (HCI) is a key topic on the Accessibility area, namely in what concerns a Smart-City environment, where humans have to interact with artefacts spread all around one particular city. In the last decade HCI has experienced a significant evolution towards a desired fully natural user interface, for example in what concerns the ability to recognize a wide range of hand gestures in real-time. Some efforts have lately been made in the hardware sector in order to deploy sensors that may gather information about the human body movements, as detailed as possible. One example of this effort is the Kinect Sensor from Microsoft. Nevertheless, although these solutions provide a solution for the body movement, they lack on the details, namely the hands, given their small dimension compared to the body as a whole. In other words, the SDKs provided by the vendors of these devices usually lack on the needed details concerning hand movements that would be needed for an accurate hand gesture recognition implementation. This paper presents an extension to the Kinect SDK based on a contour analysis for the estimation of the hand position. This algorithms are then used to provide the creation of a gesture library that might be used afterwards.

— Human-Computer Interaction (HCI) faces a great challenges in what concerns the creation of a fully natural interface that is able to recognize a wide range of hand gestures in real-time. Lately efforts have been made by the research community catalyzed by the wide appearance of depth sensors such as the one from the Microsoft Kinect sensor. Nevertheless the available solutions struggle to robustly recognize hand gestures since, compared with the rest of the body, the hand is a small region with many joints, difficult to recognize and ultimately track. This paper proposes a hand shape recognition method that takes advantage of the depth sensor and the joint tracking ability of Microsoft Kinect sensor. The proposed method relies on the analysis of the hand contour or outline and compares it with previously stored templates achieving a good recognition ratio and proving it eligible
for real-time scenarios.

An increasing number of our interactions are mediated through e-technologies. In order to enhance the human’s feeling of presence into these virtual environments, also known as telepresence, the individual is usually embodied into an avatar. The natural adaptation capabilities, underlain by the plasticity of the body schema, of the human being make a body ownership of the avatar possible, in which the user feels more like his/her virtual alter ego than himself/herself. However, this phenomenon only occurs under specific conditions. Two experiments are designed to study the human’s feeling and performance according to a scale of natural relationship between the participant and the avatar. In both experiments, the human-avatar interaction is carried out by a Natural User Interface (NUI) and the individual’s performance is assessed through a behavioural index, based on the concept of affordances, and a questionnaire of presence The first experiment shows that the feeling of telepresence and ownership seem to be greater when the avatar’s kinematics and proportions are close to those of the user. However, the efficiency to complete the task is higher for a more mechanical and stereotypical avatar. The second experiment shows that the manipulation of the viewpoint induces a similar difference across the sessions. Results are discussed in terms of the neurobehavioral processes underlying performance in virtual worlds, which seem to be based on ownership when the virtual artefact ensures a preservation of sensorimotor contingencies, and simple geometrical mapping when the conditions become more artificial.

Nowadays there is a clear increase of products or tailored solutions with the goal of better adept to the needs of
clients. In another context there is a wide growth of computers’ presence in the class rooms, in order to assist
the teacher to captivate and motivate the students using educational games. However not all teachers have the
advanced computer knowledge that would allow them to personalize games, which would benefit children by
providing tailored solutions to their specific needs. Having this problem into consideration it was designed/idealized a system that relies on a framework of game creation that allows a user with less informatics skills to create a game based on a model. Although there are many games of this type it would be useful and innovative for a teacher to be able to create a game that is personalized to the students’ needs and according to the skills that they wish to develop. This system consists in an interface where the user has to follow some established steps, in order to achieve a file containing all the game features, which is later imported to
a framework. That system allows the creation of different games, as long as these games come under the same game mechanics.