Real time motion estimation using a neural architecture implemented on GPUs

This work describes a neural network based architecture that represents and estimates object motion in videos. This architecture addresses multiple computer vision tasks such as image segmentation, object representation or characterization, motion analysis and tracking. The use of a neural network architecture allows for the simultaneous estimation of global and local motion and the representation of deformable objects. This architecture also avoids the problem of finding corresponding features while tracking moving objects. Due to the parallel nature of neural networks, the architecture has been implemented on GPUs that allows the system to meet a set of requirements such as: time constraints management, robustness, high processing speed and re-configurability. Experiments are presented that demonstrate the validity of our architecture to solve problems of mobile agents tracking and motion analysis.     

Digital design and time on device; how aesthetic experience can help to illuminate the psychological impact of living in a digital culture

ABSTRACT

Aesthetic techniques are increasingly used by marketeers to create enticing digital products. In this paper, I work with the aesthetic experiences of one audience group to consider the psychological impact of living in a culture where digital devices are deliberately designed to influence behaviour. I argue that aesthetic encounters can help with understanding the impact of the interplay between visual stimulus, affect and digital culture, in ways that may support situated understandings of mental distress in a digital age. I show how audiences respond to the artist-led research project Are We All Addicts Now? arguing that they generate ideas connected to submersion and being overwhelmed as a means of reporting on their own personal experiences of living in a digital culture that seeks to influence behaviour. The findings may have value for designers, curators and artists invested in understanding the experiential impact of digital devices.     

A backstepping controller for path‐tracking of an underactuated autonomous airship

In this paper we propose a nonlinear control approach for the path‐tracking of an autonomous underactuated airship. A backstepping controller is designed from the airship nonlinear dynamic model including wind disturbances, and further enhanced to consider actuators saturation. Control implementation issues related to airship underactuation are also addressed, namely control allocation and an attitude reference shaping to obtain a faster error correction with smoother input requests. The results obtained demonstrate the capacity of an underactuated unmanned airship to execute a realistic mission including vertical take‐off and landing, stabilization and path‐tracking, in the presence of wind disturbances, with a single robust control law. Copyright © 2008 John Wiley & Sons, Ltd.     

Formalizing interoperability for test case generation purpose

This study deals with interoperability testing of protocol implementations. The objective is to define a method for automatic test derivation based on formal definitions. First, the notion of interoperability criteria is introduced. They formally describes the conditions that two implementations must verify in order to be considered interoperable. Then, based on the equivalence of two of the defined interoperability criteria, we propose a method to derive automatically interoperability test cases that avoids the state-space explosion problem.     

Imposing temporal consistency on deep monocular body shape and pose estimation

Computational Visual Media - Accurate and temporally consistent modeling of human bodies is essential for a wide range of applications, including character animation, understanding human social...     

Coupled temperature and moisture effects on the tensile behavior of strain hardening cementitious composites (SHCC) reinforced with PVA fibers

This paper reports the experimental findings on the tensile behavior of strain-hardening cement-based composites (SHCC). The composites were subjected to the combined effects of elevated temperatures and internal moisture condition. Uniaxial tensile tests on dumbbell-shaped SHCC specimens with in situ temperature control were performed at 22, 60 and 100 °C. In addition, the effect of the internal humidity of SHCC (95, 50, 20 and 0%) coupled to the elevated temperatures was investigated. It was shown that the tensile strength decreases and the strain capacity increases with an increase in temperature. The influence of the internal moisture conditions was more significant in high temperatures. The strain capacity reduced significantly with a decrease in the humidity level. The crack pattern of the SHCC specimens was determined. Furthermore, single fiber pullout tests were performed under the considered high temperatures condition. Finally, the results are discussed based on the thermogravimetry analysis of the PVA fiber, alterations on its microstructure and surface coating.     

Cognitive,social and teaching presence in a virtual world and a text chat

Using a framework of cognitive, social, and teaching presence, the nature of learning experiences in a three-dimensional virtual world environment (Second Life) and a text-chat learning environment without visuals (TeachNet) were investigated. A mixed method of code frequencies, coherence graphs, interviews, and a survey was used. The results revealed that the TeachNet debates included more cognitive presence codes that indicate higher levels of cognitive processing than in SL debates. The teams were significantly different from each other in the collaboration style for developing arguments and in the ways to use utterances associated with cognitive, social, and teaching presences, and the groups’ collaboration style became more established with more experience with the tasks. The three critical factors–tool, tasks and group cohesion–that affect cognitive, teaching, and social presence are discussed.     

An investigation of student practices in asynchronous computer conferencing courses

This study investigated the online practices of students enrolled in graduate-level distance education courses. Using interviews and a questionnaire as data sources, the study sought to: (a) identify common practices that students adopt in asynchronous discussions, and (b) gain an understanding of why students adopt them. An analysis of the data suggests that many of the practices are coping mechanisms developed to help students more easily meet course participation requirements. Some of these are time saving strategies designed to reduce information overload (e.g., skimming messages rather than reading them carefully). Other strategies are designed to help students project an image of themselves as knowledgeable and collaborative course participants. It is argued that although these practices provide students with a level of efficiency in terms of meeting course requirements, they may inadvertently undermine learning.     

Metrics for MT evaluation: evaluating reordering

Translating between dissimilar languages requires an account of the use of divergent word orders when expressing the same semantic content. Reordering poses a serious problem for statistical machine translation systems and has generated a considerable body of research aimed at meeting its challenges. Direct evaluation of reordering requires automatic metrics that explicitly measure the quality of word order choices in translations. Current metrics, such as BLEU, only evaluate reordering indirectly. We analyse the ability of current metrics to capture reordering performance. We then introduce permutation distance metrics as a direct method for measuring word order similarity between translations and reference sentences. By correlating all metrics with a novel method for eliciting human judgements of reordering quality, we show that current metrics are largely influenced by lexical choice, and that they are not able to distinguish between different reordering scenarios. Also, we show that permutation distance metrics correlate very well with human judgements, and are impervious to lexical differences.