Methodologies for the Automatic Location of Academic and Educational Texts on the Internet

Traditionally online databases of web resources have been compiled by a human editor, or though the submissions of authors or interested parties. Considerable resources are needed to maintain a constant level of input and relevance in the face of increasing material quantity and quality, and much of what is in databases is of an ephemeral nature. These pressures dictate that many databases stagnate after an initial period of enthusiastic data entry. The solution to this problem would seem to be the automatic harvesting of resources, however, this process necessitates the automatic classification of resources as ‘appropriate’ to a given database, a problem only solved by complex text content analysis. This paper outlines the component methodologies necessary to construct such an automated harvesting system, including a number of novel approaches. In particular this paper looks at the specific problems of automatically identifying academic research work and Higher Education pedagogic materials. Where appropriate, experimental data is presented from searches in the field of Geography as well as the Earth and Environmental Sciences. In addition, appropriate software is reviewed where it exists, and future directions are outlined

Methodologies for the Automatic Location of Academic and Educational Texts on the Internet

Traditionally online databases of web resources have been compiled by a human editor, or though the submissions of authors or interested parties. Considerable resources are needed to maintain a constant level of input and relevance in the face of increasing material quantity and quality, and much of what is in databases is of an ephemeral nature. These pressures dictate that many databases stagnate after an initial period of enthusiastic data entry. The solution to this problem would seem to be the automatic harvesting of resources, however, this process necessitates the automatic classification of resources as ‘appropriate’ to a given database, a problem only solved by complex text content analysis. This paper outlines the component methodologies necessary to construct such an automated harvesting system, including a number of novel approaches. In particular this paper looks at the specific problems of automatically identifying academic research work and Higher Education pedagogic materials. Where appropriate, experimental data is presented from searches in the field of Geography as well as the Earth and Environmental Sciences. In addition, appropriate software is reviewed where it exists, and future directions are outlined

On the Geometric Principles of Surface Growth

We introduce a new equation describing epitaxial growth processes. This equation is derived from a simple variational geometric principle and it has a straightforward interpretation in terms of continuum and microscopic physics. It is also able to reproduce the critical behavior already observed, mound formation and mass conservation, but however does not fit a divergence form as the most commonly spread models of conserved surface growth. This formulation allows us to connect the results of the dynamic renormalization group analysis with intuitive geometric principles, whose generic character may well allow them to describe surface growth and other phenomena in different areas of physics

Soft core fluid in a quenched matrix of soft core particles: A mobile mixture in a model gel

We present a density-functional study of a binary phase-separating mixture of soft core particles immersed in a random matrix of quenched soft core particles of larger size. This is a model for a binary polymer mixture immersed in a crosslinked rigid polymer network. Using the replica `trick' for quenched-annealed mixtures we derive an explicit density functional theory that treats the quenched species on the level of its one-body density distribution. The relation to a set of effective external potentials acting on the annealed components is discussed. We relate matrix-induced condensation in bulk to the behaviour of the mixture around a single large particle. The interfacial properties of the binary mixture at a surface of the quenched matrix display a rich interplay between capillary condensation inside the bulk matrix and wetting phenomena at the matrix surface.Comment: 20 pages, 5 figures. Accepted for Phys. Rev.

Signal Noise Filtering Techniques in Radiation Detection Applications for Neutron Gamma Pulse Shape Discrimination

Neutron radiation often occurs as a result of radioactive decay and is accompanied by gamma radiation. This results in a mixed radiation environment comprising photons (gamma rays) and neutrons. Organic liquid scintillators are popularly used to detect both neutrons and gamma rays, where pulse shape analysis determines whether the event was caused by a neutron or a gamma-ray based on the decay characteristics of the pulse. Bespoke fast digitisers are currently widely used with organic liquid scintillators to record the pulse shape as digital samples. Pulse shape has high impact on pulse shape discrimination, especially in low energy region as it is generally difficult to discriminate a neutron event from a gamma-ray event. The quality of the discrimination of detected event is primarily determined by the quality of the pulse shape recreated using digital samples, as the discrimination is based on the characteristics of the pulse. The pulse signal is usually altered by signal noise and, the purpose of this paper is to select the best candidate for signal filtering technique to remove such high frequency noise components. It is important to ensure that the signal filtering technique is not consuming much of the processing power of the system and, it can be easily implemented in a real-time system

Birds and people in Europe

At a regional scale, species richness and human population size are frequently positively correlated across space. Such patterns may arise because both species richness and human density increase with energy availability. If the species-energy relationship is generated through the 'more individuals' hypothesis, then the prediction is that areas with high human densities will also support greater numbers of individuals from other taxa. We use the unique data available for the breeding birds in Europe to test this prediction. Overall regional densities of bird species are higher in areas with more people; species of conservation concern exhibit the same pattern. Avian density also increases faster with human density than does avian biomass, indicating that areas with a higher human density have a higher proportion of small-bodied individuals. The analyses also underline the low numbers of breeding birds in Europe relative to humans, with a median of just three individual birds per person, and 4 g of bird for every kilogram of human

Fundamental Economic Shocks and The Macroeconomy

Recently there has been renewed interest in assessing economic models in the context of specific, empirically identified economic shocks. Typically, these shocks are identified one-at-a-time, ignoring potential correlations across shocks, or are identified in the context of a structural vector autoregression (SVAR) using zero restrictions only loosely tied to economic theory. In this paper, we develop an alternative approach that utilizes measures of economic shocks explicitly derived from economic models to identify multiple orthogonal structural impulses. We use this approach to identify technology shocks, marginal-rate-of-substitution (labor supply) shocks, and monetary policy shocks in the context of a Factor Augmented VAR. We then examine the Bayesian posterior distribution for the responses of a large number of endogenous macroeconomic and financial variables to these three shocks.. The shocks account for the preponderance of output, productivity and price fluctuations. Technology shocks have a permanent impact on measures of economic activity, whereas the other shocks are more transitory. Labor inputs have little initial response to technology shocks, with the response building steadily over the 5 year period. Consumption’s sluggish response to the technology shock is inconsistent with a simple formulation of the permanent income hypothesis, but would be consistent with a model of habit formation. Monetary policy has a rather small response to technology shocks, but responds “leans against the wind” in response to the more cyclical labor supply shock. This more cyclical shock has the biggest impact on interest rates. Stock prices respond to all three shocks. A number of other empirical implications of our approach are discussed.