Engine non-containment: UK risk assessment methods

More realistic guideline data must be developed for use in aircraft design in order to comply with recent changes in British civil airworthiness requirements. Unrealistically pessimistic results were obtained when the methodology developed during the Concorde SST certification program was extended to assess catastrophic risks resulting from uncontained engine rotors

Maintaining authenticity: transferring patina from the real world to the digital to retain narrative value

This research is concerned with utilizing new technologies to harvest existing narrative, symbolic and emotive value for use in a digital environment enabling "emotional durability" (Chapman, 2005) in future design. The projects discussed in this paper have been conducted as part of PhD research by Rosemary Wallin into 'Technology for Sustainable Luxury' at University of the Arts London, and visual effects technology research undertaken by Florian Stephens at University of West London. Jonathan Chapman describes vast consumer waste being "symptomatic of failed relationships" between consumers and the goods they buy, and suggests approaches for designing love, dependency, and even cherishability into products to give them a longer lifespan. 'Failed relationships' might also be observed in the transference of physical objects to their virtual cousins. Consider the throwaway nature of digital photography when compared to the carefully preserved prints in a family album. Apple often use a skeuomorphic (Hobbs, 2012) approach to user interface design, to digitally replicate the patina and 'value' of real objects. However, true transference of physical form and texture presumably occurs when an object is scanned and a virtual 3D model is created. This paper presents three practice-based approaches to storing and transferring patina from an original object, utilizing high resolution scanning, photogrammetry, mobile applications and 3D print technologies. The objective is not merely accuracy, but evocation of the emotive data connecting the digital and physical realm. As the human face holds experience in the lines and wrinkles of the skin, so the surface of an object holds its narrative. From the signs of the craftsman to the bumps and scratches that accumulate over the life of an item over time and generations, marks gather like evidence to be read by a familiar or a trained eye. According to the time and the culture these marks are read within, they will either add to or detract from its value. These marks can be captured via complex 3D modelling and scanning technologies, which allow detailed forms to be recreated as dense 3D wireframe, but the result is often unsatisfying. 3D greyscale surfaces can never fully capture the richness of patina. Authentic surfaces require other qualities such as colour, texture and depth, but there is something else - more difficult to define. Donald A. Norman expands on the idea of emotion and objects by describing three 'levels’ of design "visceral, behavioural and reflective". Visceral is based on "look, feel and sound", behavioural is focused on an object’s use, and reflective is concerned with its message. New technology is commonly seen in terms of its ability to increase efficiency, but this research has longer-term objectives: to repair or even rebuild Chapman's 'broken relationships' and enable ‘emotionally durable' design. The PhD that has formed the context for this paper examines the concept of luxury value, and how and why the value of patina has been replaced by fashion. Luxury goods are aspirational items often emulated in the bulk of mass production. If we are to alter behaviour around consumption, one approach might be to use technology to harvest patina as a way to retain emotional, symbolic and poetic value with a view to maintaining a relationship with the things we buy

Multivariate type G Mat\'ern stochastic partial differential equation random fields

For many applications with multivariate data, random field models capturing departures from Gaussianity within realisations are appropriate. For this reason, we formulate a new class of multivariate non-Gaussian models based on systems of stochastic partial differential equations with additive type G noise whose marginal covariance functions are of Mat\'ern type. We consider four increasingly flexible constructions of the noise, where the first two are similar to existing copula-based models. In contrast to these, the latter two constructions can model non-Gaussian spatial data without replicates. Computationally efficient methods for likelihood-based parameter estimation and probabilistic prediction are proposed, and the flexibility of the suggested models is illustrated by numerical examples and two statistical applications

Ratchet effect for cold atoms in an optical lattice

The realization of a directed current for a quantum particle in a flashing asymmetric potential is studied. It is found that a positive current, i.e. in the direction expected for a conventional diffusive ratchet, can be attained at short times in the limit where the potential is weak and quantum diffusion dominates, while current reversal is obtained for stronger potentials. A single parameter, the ratio between the kicking frequency and the optical lattice potential strength, determines both the degree to which quantum effects dominate, and the possibility of obtaining a ratchet current. The effect should be readily observable in experiments.Comment: 4 pages, 3 figure