Millimeter-Wave Diffraction by a Photo-Induced Plasma Grating

Optical gratings are used extensively for beamsteering in the visible and IR range of the spectrum. Change in the dielectric permittivity of a semiconductor medium resulting from the excitation of a nonequilibrium electron-hole plasma makes it possible to extend this technique to MMW frequencies. A photo-induced plasma grating (PIPG) can be easily rewritten by changing the illumination pattern. So this technique can be used in optically controllable MMW antennas. Initial experimental work studied the diffraction of MMW propagating along a dielectric waveguide containing a PIPG. This paper reports on the diffraction of MMW propagating in free space, steered by the PIPG

How child‐centred education favours some learners more than others

Debates on how best to educate young children have been raging over the last 100 years—more often fuelled by ideological preferences rather than empirical evidence. To some extent this is hardly surprising given the difficulty of examining pupil progress in a systematic and comparative way. However, the introduction of a new child‐centred curriculum in Wales provides the opportunity to undertake just such an examination. The Foundation Phase curriculum, introduced in 2008, is designed to provide all 3‐ to 7‐year‐olds with a developmental, experiential, play‐based approach to learning. Evidence from a major 3‐year evaluation of this intervention finds that, overall, pupil progress and well‐being is fostered in those settings where the principles of the Foundation Phase have been most closely followed. However, the evidence also suggests that even within these contexts, progress is uneven and that some kinds of children seem to gain more from this approach than others. The ‘losers’ appear to be boys and those living in poverty. Drawing on the theories of Basil Bernstein, the paper explores why this may be the case and examines the relative significance of teacher dispositions, teacher–learner dynamics and the availability of resources. The paper concludes by arguing that these issues will need to be addressed if the benefits of child‐centred approaches are to benefit all

Pictorial structures for object recognition and part labeling in drawings

10.1109/ICIP.2011.6116499Proceedings - International Conference on Image Processing, ICIP3613-361

A visual dictionary attack on Picture Passwords

10.1109/ICIP.2013.67389162013 IEEE International Conference on Image Processing, ICIP 2013 - Proceedings4447-445

Hierarchical object groups for scene classification

10.1109/ICIP.2012.6467251Proceedings - International Conference on Image Processing, ICIP1881-188

It's not polite to point: Describing people with uncertain attributes

10.1109/CVPR.2013.397Proceedings of the IEEE Computer Society Conference on Computer Vision and Pattern Recognition3089-3096PIVR

Not everybody's special: Using neighbors in referring expressions with uncertain attributes

10.1109/CVPRW.2013.47IEEE Computer Society Conference on Computer Vision and Pattern Recognition Workshops269-27