Migrant workers in the East Midlands labour market 2007

This report provides a profile of international migrants in the East Midlands and their role in the regional labour marke

Runoff on rooted trees

We introduce an idealised model for overland flow generated by rain falling on a hill-slope. Our prime motivation is to show how the coalescence of runoff streams promotes the total generation of runoff. We show that, for our model, as the rate of rainfall increases in relation to the soil infiltration rate, there is a distinct phase-change. For low rainfall (the subcritical case) only the bottom of the hill-slope contributes to the total overland runoff, while for high rainfall (the supercritical case) the whole slope contributes and the total runoff increases dramatically. We identify the critical point at which the phase-change occurs, and show how it depends on the degree of coalescence. When there is no stream coalescence the critical point occurs when the rainfall rate equals the average infiltration rate, but when we allow coalescence the critical point occurs when the rainfall rate is less than the average infiltration rate, and increasing the amount of coalescence increases the total expected runoff

Migrant workers in the East Midlands labour market 2010

This report is an update of previous intelligence (Migrant Workers in the East Midlands Labour Market 2007) on the profile and economic impact of migrant labour in the East Midlands economy

Law, Biology, and Property: A New Theory of the Endowment Effect

Recent work at the intersection of law and behavioral biology has suggested numerous contexts in which legal thinking could benefit by integrating knowledge from behavioral biology. In one of those contexts, behavioral biology may help to provide theoretical foundation for, and potentially increased predictive power concerning, various psychological traits relevant to law. This Article describes an experiment that explores that context. The paradoxical psychological bias known as the endowment effect puzzles economists, skews market behavior, impedes efficient exchange of goods and rights, and thereby poses important problems for law. Although the effect is known to vary widely, there are at present no satisfying explanations for why it manifests when and how it does. Drawing on evolutionary biology, this Article provides a new theory of the endowment effect. Briefly, we hypothesize that the endowment effect is an evolved propensity of humans and, further, that the degree to which an item is evolutionarily relevant will affect the strength of the endowment effect. The theory generates a novel combination of three predictions. These are: (1) the effect is likely to be observable in many other species, including close primate relatives; (2) the prevalence of the effect in other species is likely to vary across items; and (3)the prevalence of the endowment effect will increase or decrease, respectively, with the increasing or decreasing evolutionary salience of the item in question. The authors tested these predictions in a chimpanzee (Pan troglodytes) experiment, recently published in Current Biology. The data, further explored here, are consistent with each of the three predictions. Consequently, this theory may explain why the endowment effect exists in humans and other species. It may also help both to predict and to explain some of the variability in the effect when it does manifest. And, more broadly, the results of the experiment suggest that combining life science and social science perspectives could lead to a more coherent framework for understanding the wider variety of other cognitive heuristics and biases relevant to law

Fitting a spatial-temporal rainfall model using Approximate Bayesian Computation

We fit a stochastic spatial-temporal model to high-resolution rainfall radar data for a single rainfall event. Approximate Bayesian Computation (ABC) is used to fit a model of Cox, Isham and Northrop, previously fitted using the Generalised Method of Moments (GMM). We then show that ABC readily adapts to more general, and thus more realistic, variants of the model. The Simulated Method of Moments (SMM) is used to initialise the ABC fit

Unbiased Comparative Evaluation of Ranking Functions

Eliciting relevance judgments for ranking evaluation is labor-intensive and costly, motivating careful selection of which documents to judge. Unlike traditional approaches that make this selection deterministically, probabilistic sampling has shown intriguing promise since it enables the design of estimators that are provably unbiased even when reusing data with missing judgments. In this paper, we first unify and extend these sampling approaches by viewing the evaluation problem as a Monte Carlo estimation task that applies to a large number of common IR metrics. Drawing on the theoretical clarity that this view offers, we tackle three practical evaluation scenarios: comparing two systems, comparing $k$ systems against a baseline, and ranking $k$ systems. For each scenario, we derive an estimator and a variance-optimizing sampling distribution while retaining the strengths of sampling-based evaluation, including unbiasedness, reusability despite missing data, and ease of use in practice. In addition to the theoretical contribution, we empirically evaluate our methods against previously used sampling heuristics and find that they generally cut the number of required relevance judgments at least in half.Comment: Under review; 10 page

A microgravity isolation mount

The design and preliminary testing of a system for isolating microgravity sensitive payloads from spacecraft vibrational and impulsive disturbances is discussed. The Microgravity Isolation Mount (MGIM) concept consists of a platform which floats almost freely within a limited volume inside the spacecraft, but which is constrained to follow the spacecraft in the long term by means of very weak springs. The springs are realized magnetically and form part of a six degree of freedom active magnetic suspension system. The latter operates without any physical contact between the spacecraft and the platform itself. Power and data transfer is also performed by contactless means. Specifications are given for the expected level of input disturbances and the tolerable level of platform acceleration. The structural configuration of the mount is discussed and the design of the principal elements, i.e., actuators, sensors, control loops and power/data transfer devices are described. Finally, the construction of a hardware model that is being used to verify the predicted performance of the MGIM is described

Do structured methods help eco-innovation: An evaluation of the product ideas tree diagram

This paper reports on the first test of the Product Ideas Tree diagram (PIT): a structured method aimed to help Eco-innovation. The PIT diagram structures ideas output from chaotic idea generating sessions. This study compared four ways of conducting an Eco-innovation workshop. The results show that structured methods help Eco-innovation by improving the constructive communication between the participants. Further development of the PIT diagram promises to contribute several new approaches to sustainable product and process design

Gravitational Waves from Neutron Stars with Large Toroidal B-fields

We show that NS's with large toroidal B-fields tend naturally to evolve into potent gravitational-wave (gw) emitters. The toroidal field B_t tends to distort the NS into a prolate shape, and this magnetic distortion can easily dominate over the oblateness ``frozen into'' the NS crust. An elastic NS with frozen-in B-field of this magnitude is clearly secularly unstable: the wobble angle between the NS's angular momentum J^i and the star's magnetic axis n_B^i grow on a dissipation timescale until J^i and n_B^i are orthogonal. This final orientation is clearly the optimal one for gravitational-wave (gw) emission. The basic cause of the instability is quite general, so we conjecture that the same final state is reached for a realistic NS. Assuming this, we show that for LMXB's with B_t of order 10^{13}G, the spindown from gw's is sufficient to balance the accretion torque--supporting a suggestion by Bildsten. The spindown rates of most millisecond pulsars can also be attributed to gw emission sourced by toroidal B-fields, and both these sources could be observed by LIGO II. While the first-year spindown of a newborn NS is most likely dominated by em processes, reasonable values of B_t and the (external) dipolar field B_d can lead to detectable levels of gw emission, for a newborn NS in our own galaxy.Comment: 7 pages; submitted to PRD; only minor revision