Recognising facial expressions in video sequences

We introduce a system that processes a sequence of images of a front-facing human face and recognises a set of facial expressions. We use an efficient appearance-based face tracker to locate the face in the image sequence and estimate the deformation of its non-rigid components. The tracker works in real-time. It is robust to strong illumination changes and factors out changes in appearance caused by illumination from changes due to face deformation. We adopt a model-based approach for facial expression recognition. In our model, an image of a face is represented by a point in a deformation space. The variability of the classes of images associated to facial expressions are represented by a set of samples which model a low-dimensional manifold in the space of deformations. We introduce a probabilistic procedure based on a nearest-neighbour approach to combine the information provided by the incoming image sequence with the prior information stored in the expression manifold in order to compute a posterior probability associated to a facial expression. In the experiments conducted we show that this system is able to work in an unconstrained environment with strong changes in illumination and face location. It achieves an 89\% recognition rate in a set of 333 sequences from the Cohn-Kanade data base

On the ability of virtual agents to decrease cognitive load: an experimental study

When attempting to solve a problem, humans call upon cognitive resources. These resources are limited, and the degree of their utilisation is described as cognitive load. While the number of parameters to be taken into account and to be processed by modern-day knowledge workers increases, their cognitive resources do not. Research shows that too high a load can increase stress and failure rates and decrease the work satisfaction and performance of employees. It is thus in the interest of organisations to reduce the cognitive load of their employees and keep it at a moderate level. One way to achieve this may be the application of virtual assistants (VAs), software programs, that can be addressed via voice or text commands and respond to the users’ input. This study uses a laboratory experiment with N = 91 participants comparing two groups in their ability to solve a task. One group was able to make use of a VA while the other could not. Besides task performance, the cognitive load of the participants was measured. Results show that (a) cognitive load is negatively related to task performance, (b) the group using the VA performed better at the task and (c) the group using the VA had a lower cognitive load. These findings show that VAs are a viable way to support employees and can increase their performance. It adds to the growing field of IS research on VAs by expanding the field for the concept of cognitive load

Developmental course of conversational behaviour of children with 22q11.2 deletion syndrome and Williams syndrome

This study investigated three conversational subskills in children with 22q11.2 deletion syndrome (22q11.2DS, n = 8, ages 7–13) and Williams syndrome (WS, n = 8, ages 6–12). We re-evaluated these subskills after 18 to 24 months and compared them to those of peers with idiopathic intellectual disability (IID) and IID and comorbid autism spectrum disorders (IID+ASD). Children with 22q11.2DS became less actively involved over time. Lower assertiveness than in children with IID was demonstrated. They seemed less impaired in terms of accounting for listener’s knowledge than children with IID+ASD. Children with WS showed greater difficulties with discourse management compared to children with IID and 22q11.2DS. They had similar levels of conversational impairments to children with IID+ASD but these were caused by different shortcomings. Over time taking account of listener’s knowledge became challenging for them. Findings suggest that children with 22q11.2DS and those with WS would benefit from conversational skills support and that regular re-evaluation is needed to anticipate conversational challenges

Supporting Information Access in Next Generation Digital Library Architectures

Current developments on Service-oriented Architectures, Peer-to-Peer and Grid computing promise more open and flexible architectures for digital libraries