4,983,817 research outputs found
Testing the RPI data for consistency with the theory of the cost-of-living index
This paper tests the published section level price and weight data
used in the compilation of the UK Retail Prices Index for consistency
with the theory of the cost-of-living index. We use a nonparametric test
of theoretical consistency and bootstrap statistical methods to estimate
the probability of consistency
Testing the RPI data for consistency with the theory of the cost-of-living index
This paper tests the published section level price and weight dataused in the compilation of the UK Retail Prices Index for consistencywith the theory of the cost-of-living index. We use a nonparametric testof theoretical consistency and bootstrap statistical methods to estimatethe probability of consistency.
Generalized Inpainting Method for Hyperspectral Image Acquisition
A recently designed hyperspectral imaging device enables multiplexed
acquisition of an entire data volume in a single snapshot thanks to
monolithically-integrated spectral filters. Such an agile imaging technique
comes at the cost of a reduced spatial resolution and the need for a
demosaicing procedure on its interleaved data. In this work, we address both
issues and propose an approach inspired by recent developments in compressed
sensing and analysis sparse models. We formulate our superresolution and
demosaicing task as a 3-D generalized inpainting problem. Interestingly, the
target spatial resolution can be adjusted for mitigating the compression level
of our sensing. The reconstruction procedure uses a fast greedy method called
Pseudo-inverse IHT. We also show on simulations that a random arrangement of
the spectral filters on the sensor is preferable to regular mosaic layout as it
improves the quality of the reconstruction. The efficiency of our technique is
demonstrated through numerical experiments on both synthetic and real data as
acquired by the snapshot imager.Comment: Keywords: Hyperspectral, inpainting, iterative hard thresholding,
sparse models, CMOS, Fabry-P\'ero
Image quality and security through nonlinear joint transform encryption
Postprint (published version
The impact of agri-environment schemes on pollination services in England
Agri-environment schemes fund landholders to manage land to achieve environmental objectives and
other public goods. Previous research has shown that individual scheme interventions can boost wild
pollinator populations locally. However, the effect of an entire scheme at a national scale has never
previously been assessed.
The location of every intervention implemented in England during 2016 was mapped and schemesâ
predicted impact on bee abundance and pollination services was modelled using a validated, processbased spatial model (poll4pop), which simulates foraging and population dynamics. The study
considered four wild bee guilds (incorporating bumblebees and solitary bees) and their visitation rates
to four pollinator-dependent crops (oilseed rape, field beans, orchard fruit and strawberries). The
modelling predicted that the scheme significantly increased ground-nesting (but not tree/cavitynesting) bee populations nationally. There were no significant increases in crop visitation at national
scale, but some locally significant increases in ground-nesting bumblebee visitation to oilseed rape and
field beans were predicted.
Linear regression at 10 km scale was used to determine which interventions were driving increased
oilseed rape and field bean visitation and found that hedgerow/woodland edge management
dominated, due to high resource quality. Floral margins were estimated to provide more limited
benefit, due to later resource phenology and low uptake. Fallow also had a strong effect, despite lower
relative resource quality, implying effective placement with respect to crops.
Finally, the effect of additional tree-planting interventions (hedgerows, agroforestry, and woodland)
on bumblebee abundance and crop visitation (oilseed rape, field beans) was studied. This showed that
hedgerow planting would deliver the greatest increase in bumblebee abundance, whereas fruit or
willow agroforestry would increase crop visitation the most, due to higher co-location.
Based on these findings, recommendations are set out for design of future schemes to help deliver
greater and more resilient crop pollination services in arable landscapes
Image Similarity Metrics in Image Registration
Measures of image similarity that inspect the intensity probability distribution of the images have proved extremely popular in image registration applications. The joint entropy of the intensity distributions and the marginal entropies of the individual images are combined to produce properties such as resistance to loss of information in one image and invariance to changes in image overlap during registration. However information theoretic cost functions are largely used empirically. This work attempts to describe image similarity measures within a formal mathematical metric framework. Redefining mutual information as a metric is shown to lead naturally to the standardised variant, normalised mutual information
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