Diagnostic of Rolling Element Bearings with Envelope Analysis in Non-Stationary Conditions

In the field of rolling element bearing diagnostics, envelope analysis has gained in the last years a leading role among the different digital signal processing techniques. The original constraint of constant operating speed has been relaxed thanks to the combination of this technique with the computed order tracking, able to resample signals at constant angular increments. In this way, the field of application of this technique has been extended to cases in which small speed fluctuations occur, maintaining high effectiveness and efficiency. In order to make this algorithm suitable to all industrial applications, the constraint on speed has to be removed completely. In fact, in many applications, the coincidence of high bearing loads, and therefore high diagnostic capability, with acceleration-deceleration phases represents a further incentive in this direction. This chapter presents a procedure for the application of envelope analysis to speed transients. The effect of load variation on the proposed technique will be also qualitatively addressed.

Towards condition-invariant, top-down visual place recognition

In this paper we present a novel place recognition algorithm inspired by recent discoveries in human visual neuroscience. The algorithm combines intolerant but fast low resolution whole image matching with highly tolerant, sub-image patch matching processes. The approach does not require prior training and works on single images (although we use a cohort normalization score to exploit temporal frame information), alleviating the need for either a velocity signal or image sequence, differentiating it from current state of the art methods. We demonstrate the algorithm on the challenging Alderley sunny day – rainy night dataset, which has only been previously solved by integrating over 320 frame long image sequences. The system is able to achieve 21.24% recall at 100% precision, matching drastically different day and night-time images of places while successfully rejecting match hypotheses between highly aliased images of different places. The results provide a new benchmark for single image, condition-invariant place recognition.

Do look now : re-imagining and re-purposing audiovisual creative practice

The appropriation and elaborate re-working of mediated images and sound stand in a fluid relationship with established notions such as creativity, originality and artistic freedom. The evocative, recontextualised montage works of the eminent video artists Christian Marclay (The Clock) and Tracey Moffatt (Other; Love) may be viewed critically in the light of several theorists’ work, such as Walter Benjamin’s ideas on the crisis of reproduction and reactivation. The ironic pastiche, Do Look Now, a recent video installation work, is presented here as a similar dialogical intervention, representing a subversive deconstruction and critique of filmic codes and conventions, as well as being a new work crafted out of old film clips. (The films quoted in the work are listed here in an Appendix). These practical provocations are framed within a renewed, ‘queering’ investigation of creative works. Such an exploration is, arguably, both illuminating and liberating for particular practitioners and researchers engaged with the unpredictable intersections of creative meaning-making in a heavily legalised, mediated and digitised world.