Multimodal One-Shot Learning of Speech and Images

Imagine a robot is shown new concepts visually together with spoken tags, e.g. "milk", "eggs", "butter". After seeing one paired audio-visual example per class, it is shown a new set of unseen instances of these objects, and asked to pick the "milk". Without receiving any hard labels, could it learn to match the new continuous speech input to the correct visual instance? Although unimodal one-shot learning has been studied, where one labelled example in a single modality is given per class, this example motivates multimodal one-shot learning. Our main contribution is to formally define this task, and to propose several baseline and advanced models. We use a dataset of paired spoken and visual digits to specifically investigate recent advances in Siamese convolutional neural networks. Our best Siamese model achieves twice the accuracy of a nearest neighbour model using pixel-distance over images and dynamic time warping over speech in 11-way cross-modal matching.Comment: 5 pages, 1 figure, 3 tables; accepted to ICASSP 201

Mixed Operators in Compressed Sensing

Applications of compressed sensing motivate the possibility of using different operators to encode and decode a signal of interest. Since it is clear that the operators cannot be too different, we can view the discrepancy between the two matrices as a perturbation. The stability of L1-minimization and greedy algorithms to recover the signal in the presence of additive noise is by now well-known. Recently however, work has been done to analyze these methods with noise in the measurement matrix, which generates a multiplicative noise term. This new framework of generalized perturbations (i.e., both additive and multiplicative noise) extends the prior work on stable signal recovery from incomplete and inaccurate measurements of Candes, Romberg and Tao using Basis Pursuit (BP), and of Needell and Tropp using Compressive Sampling Matching Pursuit (CoSaMP). We show, under reasonable assumptions, that the stability of the reconstructed signal by both BP and CoSaMP is limited by the noise level in the observation. Our analysis extends easily to arbitrary greedy methods.Comment: CISS 2010 (44th Annual Conference on Information Sciences and Systems

Rapid billet loader aids extrusion of refractory metals

A combination gravity and manually powered rapid billet loader reduces the time required for transferring hot metal billets from a heating furnace to an extrusion press. Positioned between the furnace and extrusion press, this loader is a simple slide-delivery device

Study of Staebler-Wronsky degradation effect in a Si:H based P-I-N solar cells

The objective of this study is to improve the stability and efficiency of thin solar cells with emphasis on a-Si:H devices. The research project was broken down into three main phases. The first involves designing and building a UHV glow discharge system; the second involves making good quality films and eventually efficient cells; the final phase will be analytical

Weak-Scale Hidden Sector and Energy Transport in Fireball Models of Gamma-Ray Bursts

The annihilation of pairs of very weakly interacting particles in the neibourghood of gamma-ray sources is introduced here as a plausible mechanism to overcome the baryon load problem. This way we can explain how these very high energy gamma-ray bursts can be powered at the onset of very energetic events like supernovae (collapsars) explosions or coalescences of binary neutron stars. Our approach uses the weak-scale hidden sector models in which the Higgs sector of the standard model is extended to include a gauge singlet that only interacts with the Higgs particle. These particles would be produced either during the implosion of the red supergiant star core or at the aftermath of a neutron star binary merger. The whole energetics and timescales of the relativistic blast wave, the fireball, are reproduced.Comment: 4 pp, 1 ps fig, text revised and improve

New spaces of food justice

‘Food is fundamental to life’ (Sbicca 2012, 456) and this shared need establishes food as a site of potential for connective and convivial practices and relations. Yet, when we realise that more than one billion people are undernourished worldwide (Food Ethics Council 2010), despite the fact that the world produces enough food to feed billions more than the current global population of seven billion (Holt-Gimenez et al. 2012), the social, political, economic and environmental challenges posed by contemporary food systems start to become apparent. Given current global production levels – whether we agree with the social and environmental implications of these or not – it is clear that malnutrition rates worldwide are not simply an indicator of agricultural praxis but demonstrate the continued, broader social and structural issues of access, equity and justice. Recognising that many feel increasingly disenfranchised from formal political representation, marginalised by a hegemonic neoliberal capitalism or disconnected from ‘healthy’ social or environmental relations, food offers an opportunity to re-engage individuals and society with critical questions and practices of justice because, as Allen (2008, 159) notes, ‘no other public issue is as accessible to people in their daily lives as that of food justice. Everyone – regardless of age, gender, ethnicity, or social class – eats. We are all involved and we are all implicated’. The multiplicity of ways in which we can engage with food – including growing, buying, eating, cooking, writing, processing, marketing, selling and watching – enacts its radical potential as a set of dynamic socio-material relations (Alkon 2013; Alkon et al. 2013) that can both conform to and subvert existing practices and understandings, enabling food to ‘speak’ to many different people in a range of different contexts. Although this multiplicity has its dangers (Heynen, Kurtz, and Trauger 2012), it also means that food matters and matters in complex and diverse ways: ‘It rallies people and it often induces unexpected changes in society’ (Van der Ploeg 2013, 999)

Analysis of current density and related parameters in spinal cord stimulation

A volume conductor model of the spinal cord and surrounding anatomical structures is used to calculate current (and current density) charge per pulse, and maximum charge density per pulse at the contact surface of the electrode in the dorsal epidural space, in the dorsal columns of the spinal cord and in the dorsal roots. The effects of various contact configurations (mono-, bi-, and tripole), contact area and spacing, pulsewidth and distance between contacts and spinal cord on these electrical parameters were investigated under conditions similar to those in clinical spinal cord stimulation. At the threshold stimulus of a large dorsal column fiber, current density and charge density per pulse at the contact surface were found to be highest (1.9·105 ¿A/cm2 and 39.1 ¿C/cm2 ·p, respectively) when the contact surface was only 0.7 mm 2. When stimulating with a pulse of 500 ¿s, highest charge per pulse (0.92 ¿C/p), and the largest charge density per pulse in the dorsal columns (1.59 ¿C/cm2·p) occurred. It is concluded that of all stimulation parameters that can be selected freely, only pulsewidth affects the charge and charge density per pulse in the nervous tissue, whereas both pulsewidth and contact area strongly affect these parameters in the nonnervous tissue neighboring the electrode contact

Hypersonic Research Vehicle (HRV) real-time flight test support feasibility and requirements study. Part 2: Remote computation support for flight systems functions

The requirements are assessed for the use of remote computation to support HRV flight testing. First, remote computational requirements were developed to support functions that will eventually be performed onboard operational vehicles of this type. These functions which either cannot be performed onboard in the time frame of initial HRV flight test programs because the technology of airborne computers will not be sufficiently advanced to support the computational loads required, or it is not desirable to perform the functions onboard in the flight test program for other reasons. Second, remote computational support either required or highly desirable to conduct flight testing itself was addressed. The use is proposed of an Automated Flight Management System which is described in conceptual detail. Third, autonomous operations is discussed and finally, unmanned operations