49,376 research outputs found
Infrared emissivities and absorptivities of gases
Approximate analytic expressions are obtained for the "effective band widths" and emissivities of diatomic molecules at elevated pressures. The absorptivities of molecular vibration‐rotation bands are evaluated for radiation emitted by similar molecular vibration‐rotation bands and for radiation emitted by blackbodies. The results obtained for the absorptivity calculations compare favorably with available empirical correlations for H_2O. The postulated model does not apply to CO_2 and, therefore, no satisfactory theoretical formula has been derived for the absorptivities of this molecule. The appendix (by A. Thomson) is devoted to a critical examination of the limits of validity of the effective band‐width concept for different molecules
Systoles of Hyperbolic Manifolds
We show that for every and any there exists a compact
hyperbolic -manifold with a closed geodesic of length less than .
When is sufficiently small these manifolds are non-arithmetic, and
they are obtained by a generalised inbreeding construction which was first
suggested by Agol for . We also show that for the volumes of
these manifolds grow at least as when .Comment: 12 pages; revised following referee's comments; to appear in
Algebraic and Geometric Topolog
Evaluation of GHA’s youth diversionary programme
To assist with funding decisions in this area and to build an evidence base, GHA commissioned an evaluation of a selection of its youth diversionary programmes in 2007
Assessing the health impact of local amenities: a qualitative study of contrasting experiences of local swimming pool and leisure provision in two areas of Glasgow
Study objective: To assess the health impacts of local public swimming pool and leisure provision.
Design: Retrospective qualitative study using focus groups. Reports from two areas with contrasting experience of provision of a public swimming pool (opening and closure) were compared within the context of general reports about health and neighbourhood.
Setting: Two deprived neighbourhoods in south Glasgow.
Participants: Local adult residents of mixed ages, accessed through local community groups.
Main results: In both areas the swimming pool was reported as an important amenity that was linked to health and wellbeing. However, few residents reported regular use of the pool for physical activity. Use of the pool facility for social contact was directly linked to reports of relief of stress and isolation, and improved mental health. Pool closure was one in a series of amenity closures and area decline and was used to represent other area changes. Health impacts were strongly linked to the pool closure. The pool opening was associated with local area regeneration, similar but less prominent links between swimming pool provision and health were reported. Health benefits of social contact were diffuse and linked to other local amenities as well as the new pool facility.
Conclusions: Although theoretically linked to increased physical activity, the health benefits conveyed by the swimming pool may be more closely linked to the facilitation of social contact, and a supervised facility for young children. The use of qualitative work to investigate area based change provides rich contextual data to strengthen and explain the reported health impacts
Solvation forces in Ising films with long-range boundary fields: density-matrix renormalization-group study
Using the quasi-exact density-matrix renormalization-group method we
calculate the solvation forces in two-dimensional Ising films of thickness L
subject to identical algebraically decaying boundary fields with various decay
exponents p. At the bulk critical point the solvation force acquires a
universal contribution which is long-ranged in L due to the critical
fluctuations, a phenomenon known as the critical Casimir effect. For p = 2, 3
and 50, we study the scaling behaviour of the solvation force along the
pseudo-phase coexistence and along the critical and sub-critical isotherms.Comment: 9 pages, 6 figures, accepted to Molecular Physic
Power in global agriculture: economics, politics, and natural resources
Recent events, such as the 2008 food price crisis, have focussed global attention on the agriculture and food sectors. In particular, many countries have become increasingly concerned with the issue of ensuring the security of their food supply and one key element of this is who has power within the food supply chain. Through examining three dimensions of power – Economic, Political, and Natural Resources – this paper explores where power currently lies in world agriculture and how this might change in the future. Whilst recognising that power is a somewhat abstract concept, through a process of deriving potential indicators, a picture of the distribution of power is drawn. These indicators were also used to develop a simple 'global power index'. The power index indicates that the US and the EU dominate world agriculture in terms of economics and politics, but are potentially vulnerable in terms of their possession of natural resources. On the other hand, the emerging economies have lower political and corporate power, but seem better placed in terms of natural resources. The paper concludes by discussing the implications of these findings for the main food producing regions
Deep Multitask Learning for Semantic Dependency Parsing
We present a deep neural architecture that parses sentences into three
semantic dependency graph formalisms. By using efficient, nearly arc-factored
inference and a bidirectional-LSTM composed with a multi-layer perceptron, our
base system is able to significantly improve the state of the art for semantic
dependency parsing, without using hand-engineered features or syntax. We then
explore two multitask learning approaches---one that shares parameters across
formalisms, and one that uses higher-order structures to predict the graphs
jointly. We find that both approaches improve performance across formalisms on
average, achieving a new state of the art. Our code is open-source and
available at https://github.com/Noahs-ARK/NeurboParser.Comment: Proceedings of ACL 201
Determinants of the Closing Probability of Residential Mortgage Applications
After allowing applicants to "lock" the interest rate, mortgage originators are concerned with protecting themselves from adverse outcomes due to interest-rate changes. One may expect applicants would strive to close applications when rates rose, while letting themselves fall out when rates decline. Our results show that applicant response to interest-rate changes and volatility are modest. The most important predictor of closing probability is the length of the lock period, with shorter locks being more likely to close. Applications for single-family are more likely to close than are those for multiunit dwellings. Applications for owner-occupied properties are more likely to close than are those for investment properties. Applicant characteristics such as loan affordability, education and age have a small influence on closing rate. Gender has an effect for some loan programs, and marital status appears to be irrelevant. Discount points affect refinance mortgages more than purchase mortgages. Conventional applications are more likely to close than FHA and VA, and applications for refinance, in general, are less likely to close. Results are mixed for ARM and fifteen-year applications, as well as for whether it was the original application, or a relock.
- …
