Computationally efficient modeling of proprioceptive signals in the upper limb for prostheses: a simulation study.

Accurate models of proprioceptive neural patterns could one day play an important role in the creation of an intuitive proprioceptive neural prosthesis for amputees. This paper looks at combining efficient implementations of biomechanical and proprioceptor models in order to generate signals that mimic human muscular proprioceptive patterns for future experimental work in prosthesis feedback. A neuro-musculoskeletal model of the upper limb with 7 degrees of freedom and 17 muscles is presented and generates real time estimates of muscle spindle and Golgi Tendon Organ neural firing patterns. Unlike previous neuro-musculoskeletal models, muscle activation and excitation levels are unknowns in this application and an inverse dynamics tool (static optimisation) is integrated to estimate these variables. A proprioceptive prosthesis will need to be portable and this is incompatible with the computationally demanding nature of standard biomechanical and proprioceptor modelling. This paper uses and proposes a number of approximations and optimisations to make real time operation on portable hardware feasible. Finally technical obstacles to mimicking natural feedback for an intuitive proprioceptive prosthesis, as well as issues and limitations with existing models, are identified and discussed

An Energy-Efficient, Dynamic Voltage Scaling Neural Stimulator for a Proprioceptive Prosthesis

Accepted versio

An Energy-Efficient, Dynamic Voltage Scaling Neural Stimulator for a Proprioceptive Prosthesis

Accepted versio

Exact energy spectrum of a two-temperature kinetic Ising model

The exact energy spectrum is developed for a two temperature kinetic Ising spin chain, and its dual reaction diffusion system with spatially alternating pair annihilation and creation rates. Symmetries of the system pseudo-Hamiltonian that enable calculation of the spectrum are also used to derive explicit state vectors for small system sizes, and to make observations regarding state vectors in the general case. Physical consequences of the surprisingly simple form for the eigenvalues are also discussed

Earworms ("stuck song syndrome"): towards a natural history of intrusive thoughts

Two studies examine the experience of “earworms”, unwanted catchy tunes that repeat. Survey data show that the experience is widespread but earworms are not generally considered problematic, although those who consider music to be important to them report earworms as longer, and harder to control, than those who consider music as less important. The tunes which produce these experiences vary considerably between individuals but are always familiar to those who experience them. A diary study confirms these findings and also indicates that, although earworm recurrence is relatively uncommon and unlikely to persist for longer than 24 hours, the length of both the earworm and the earworm experience frequently exceed standard estimates of auditory memory capacity. Active attempts to block or eliminate the earworm are less successful than passive acceptance, consistent with Wegner’s (1994) theory of ironic mental control

Service of process in the United States under Insolvency Rule 12.12

Explains the procedure to be followed by a UK based liquidator wishing to serve insolvency proceedings on parties based in the US under the Insolvency Rules 1986 r.12.12. Discusses the rule's requirements for obtaining leave of the court for service outside the jurisdiction, the court's discretion to order the manner of service, including the approach of the Chancery Division in Re Busytoday Ltd, and the obligations imposed by the Hague Convention on the Service Abroad of Judicial and Extrajudicial Documents in Civil or Commercial Matters 1965. Evaluates the methods of service authorised by the Convention and details the main elements involved in service by the Central Authority route or by a local process server

Multiple Texture Boltzmann Machines

We assess the generative power of the mPoTmodel of [10] with tiled-convolutional weight sharing as a model for visual textures by specifically training on this task, evaluating model performance on texture synthesis and inpainting tasks using quantitative metrics. We also analyze the relative importance of the mean and covariance parts of the mPoT model by comparing its performance to those of its subcomponents, tiled-convolutional versions of the PoT/FoE and Gaussian-Bernoulli restricted Boltzmann machine (GB-RBM). Our results suggest that while state-of-the-art or better performance can be achieved using the mPoT, similar performance can be achieved with the mean-only model. We then develop a model for multiple textures based on the GB-RBM, using a shared set of weights but texturespecific hidden unit biases. We show comparable performance of the multiple texture model to individually trained texture models.

Minimal covers of the prisms and antiprisms

This paper contains a classication of the regular minimal abstract polytopes that act as covers for the convex polyhedral prisms and antiprisms. It includes a detailed discussion of their topological structure, and completes the enumeration of such covers for convex uniform polyhedra. Additionally, this paper addresses related structural questions in the theory of string C-groups.Comment: 22 pages, 8 figure

Formation of the Leonid meteor stream and storm

It is well known that some meteor showers display a very high level of activity at certain times, the most famous being the Leonid shower with very spectacular displays at roughly 33 year intervals. This period being also the period of the parent comet of the stream, Comet Tempel-Tuttle. An investigation of the geometry of the comet and the Earth at the time of each high activity occurrence by Yeomans suggests that most of the meteoroids are found outside the cometary orbit and lagging the comet. The formation process of such a stream by numerically integrating the orbits of dust particles ejected from the comet and moving under the influence of gravity and radiation pressure are simulated. The intersection of these dust particles with the Earth is also considered and it is concluded that about 12 percent of the ejected particles may be observed and that of those observable, 63 percent will be outside the cometary orbit and behind the comet

Public attitudes to air pollution from road vehicles

An assessment of the environmental effects of any new road scheme is currently recommended by the Department of Transport, but the existing appraisal does not include an evaluation of public nuisance from vehicle-derived air pollution. This research project has investigated the subjective nuisance effects of air pollution from road traffic on the public through the simultaneous measurement of public attitudes towards vehicle-generated nuisance and air quality in residential and commercial areas. Roadside pollutant concentrations were monitored during four London-based surveys involving the measurement of CO, NOx, gaseous hydrocarbons, SO₂, O₃, carbonyl compounds, smoke and total suspended particulates. At these roadside locations, traffic flow and classification data were collected together with local and regional meteorological data. To extend the database, air quality data was collected from five other cities within the UK. These data were obtained from the relevant local authority monitoring sites and/or DoE Enhanced Urban Network sites. Monitored air pollutant concentrations were found to be similar to those recorded previously at comparable sites. At the roadside locations, the air quality according to the DoE's public information criteria was typically 'very good' for SO₂and O₃, but sometimes 'poor' for NO₂. At the urban background locations, air quality was generally very good. Positive and significant correlations were recorded between the major vehicular primary pollutants of CO, NO and NMHC and traffic flow at all sites. NO₂/NOx ratios were lower at the commercial locations than at the residential locations, reflecting the lack of available O₃ for NO-NO₂ conversion. Roadside black smoke concentrations were much higher than those typically recorded at rooftop level in the UK, probably indicating the strong influence of diesel vehicle emissions and/or the extreme 'blackness' of diesel particles, and suggesting that the 8-Port technique may overestimate roadside black smoke concentrations. Social surveys, utilising questionnaires developed especially for this research, were performed to assess the causes, extent and magnitude of public nuisance from vehicle-derived air pollution at each of the pollutant monitoring sites. The survey data indicates the high relative importance of air pollution from road traffic when compared to other social issues, indicating that concern for the environment is now an established social issue rather than a transient preoccupation. Local environmental issues were generally of relatively low priority, although traffic-related nuisances were very important local environmental nuisances. Indoors, noise from road traffic was the most important vehicle-derived disturbance with the major concerns relating to the soiling of surfaces and the malodour of fumes. Outdoors, disturbance from smoke, fumes and odour was the most frequently complained about traffic-induced nuisance, with danger ranking equally highly. Most respondents were concerned about the effects of fumes upon their health, with adverse effects widely assumed. Significant differences in disturbance between sites in the same and different cities, between females and males and between different age groups were recorded. No significant differences in annoyance were noted between smokers/non-smokers and different socio-economic groupings. At each location, pollutant concentrations are discussed and the results of the social surveys are presented and interpreted. The relationships between nuisance and pollutant concentrations are examined graphically and a mathematical relationship between black smoke concentrations and disturbance score is produced. This relationship is not considered to be sufficiently accurate for predictive purposes and an alternative method for estimating nuisance is proposed