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Use of colour for hand-filled form analysis and recognition
Colour information in form analysis is currently under utilised. As technology has advanced and computing costs have reduced, the processing of forms in colour has now become practicable. This paper describes a novel colour-based approach to the extraction of filled data from colour form images. Images are first quantised to reduce the colour complexity and data is extracted by examining the colour characteristics of the images. The improved performance of the proposed method has been verified by comparing the processing time, recognition rate, extraction precision and recall rate to that of an equivalent black and white system
Soil Fertility Protocol
The purpose of this resource is to measure the amounts of nitrogen, phosphorous and potassium in each horizon in a soil profile. Using a NPK test kit, students mix a dry, sieved soil sample into a solution and chemically extract the N, P, and K as nitrate, phosphate, and potassium. The N, P, and K amounts in the sample are determined by comparing the solution to a color chart. Students describe the N, P, K amounts as high, medium, low, or none. These measurements are conducted three times for each horizon. Educational levels: Middle school, High school
Effect of hydrogel particle additives on water-accessible pore structure of sandy soils: A custom pressure plate apparatus and capillary bundle model
To probe the effects of hydrogel particle additives on the water-accessible
pore structure of sandy soils, we introduce a custom pressure plate method in
which the volume of water expelled from a wet granular packing is measured as a
function of applied pressure. Using a capillary bundle model, we show that the
differential change in retained water per pressure increment is directly
related to the cumulative cross-sectional area distribution of the
water-accessible pores with radii less than . This is validated by
measurements of water expelled from a model sandy soil composed of 2 mm
diameter glass beads. In particular, the expelled water is found to depend
dramatically on sample height and that analysis using the capillary bundle
model gives the same pore size distribution for all samples. The distribution
is found to be approximately log-normal, and the total cross-sectional area
fraction of the accessible pore space is found to be . We then report
on how the pore distribution and total water-accessible area fraction are
affected by superabsorbent hydrogel particle additives, uniformly mixed into a
fixed-height sample at varying concentrations. Under both fixed volume and free
swelling conditions, the total area fraction of water-accessible pore space in
a packing decreases exponentially as the gel concentration increases. The size
distribution of the pores is significantly modified by the swollen hydrogel
particles, such that large pores are clogged while small pores are formed
Obtaining Self-similar Scalings in Focusing Flows
The surface structure of converging thin fluid films displays self-similar
behavior, as was shown in the work by Diez et al [Q. Appl. Math 210, 155,
1990]. Extracting the related similarity scaling exponents from either
numerical or experimental data is non-trivial. Here we provide two such
methods. We apply them to experimental and numerical data on converging fluid
films driven by both surface tension and gravitational forcing. In the limit of
pure gravitational driving, we recover Diez' semi-analytic result, but our
methods also allow us to explore the entire regime of mixed capillary and
gravitational driving, up to entirely surface tension driven flows. We find
scaling forms of smoothly varying exponents up to surprisingly small Bond
numbers. Our experimental results are in reasonable agreement with our
numerical simulations, which confirm theoretically obtained relations between
the scaling exponents.Comment: 11 pages, 11 figures, accepted for Phys Rev
A machine learning approach for layout inference in spreadsheets
Spreadsheet applications are one of the most used tools for content generation and presentation in industry and the Web. In spite of this success, there does not exist a comprehensive approach to automatically extract and reuse the richness of data maintained in this format. The biggest obstacle is the lack of awareness about the structure of the data in spreadsheets, which otherwise could provide the means to automatically understand and extract knowledge from these files. In this paper, we propose a classification approach to discover the layout of tables in spreadsheets. Therefore, we focus on the cell level, considering a wide range of features not covered before by related work. We evaluated the performance of our classifiers on a large dataset covering three different corpora from various domains. Finally, our work includes a novel technique for detecting and repairing incorrectly classified cells in a post-processing step. The experimental results show that our approach deliver s very high accuracy bringing us a crucial step closer towards automatic table extraction.Peer ReviewedPostprint (published version
Spitzer infrared spectrometer 16ÎŒm observations of the GOODS fields
We present Spitzer 16ÎŒm imaging of the Great Observatories Origins Deep Survey (GOODS) fields. We survey
150 arcmin^2 in each of the two GOODS fields (North and South), to an average 3Ï depth of 40 and 65 ÎŒJy,
respectively. We detect ~1300 sources in both fields combined. We validate the photometry using the 3â24ÎŒm
spectral energy distribution of stars in the fields compared to Spitzer spectroscopic templates. Comparison with
ISOCAM and AKARI observations in the same fields shows reasonable agreement, though the uncertainties are
large. We provide a catalog of photometry, with sources cross-correlated with available Spitzer, Chandra, and
Hubble Space Telescope data. Galaxy number counts show good agreement with previous results from ISOCAM
and AKARI with improved uncertainties. We examine the 16â24ÎŒm flux ratio and find that for most sources it
lies within the expected locus for starbursts and infrared luminous galaxies. A color cut of S_(16)/S_(24) > 1.4 selects
mostly sources which lie at 1.1 < z < 1.6, where the 24ÎŒm passband contains both the redshifted 9.7 ÎŒm silicate
absorption and the minimum between polycyclic aromatic hydrocarbon emission peaks. We measure the integrated
galaxy light of 16ÎŒm sources and find a lower limit on the galaxy contribution to the extragalactic background
light at this wavelength to be 2.2 ± 0.2 nW m^(â2) sr^(â1)
Probing the X-Ray Binary Populations of the Ring Galaxy NGC 1291
We present Chandra studies of the X-ray binary (XRB) populations in the bulge
and ring regions of the ring galaxy NGC 1291. We detect 169 X-ray point sources
in the galaxy, 75 in the bulge and 71 in the ring, utilizing the four available
Chandra observations totaling an effective exposure of 179 ks. We report
photometric properties of these sources in a point-source catalog. There are
~40% of the bulge sources and ~25% of the ring sources showing >3\sigma
long-term variability in their X-ray count rate. The X-ray colors suggest that
a significant fraction of the bulge (~75%) and ring (~65%) sources are likely
low-mass X-ray binaries (LMXBs). The spectra of the nuclear source indicate
that it is a low-luminosity AGN with moderate obscuration; spectral variability
is observed between individual observations. We construct 0.3-8.0 keV X-ray
luminosity functions (XLFs) for the bulge and ring XRB populations, taking into
account the detection incompleteness and background AGN contamination. We reach
90% completeness limits of ~1.5\times10^{37} and ~2.2\times10^{37} erg/s for
the bulge and ring populations, respectively. Both XLFs can be fit with a
broken power-law model, and the shapes are consistent with those expected for
populations dominated by LMXBs. We perform detailed population synthesis
modeling of the XRB populations in NGC 1291, which suggests that the observed
combined XLF is dominated by an old LMXB population. We compare the bulge and
ring XRB populations, and argue that the ring XRBs are associated with a
younger stellar population than the bulge sources, based on the relative
overdensity of X-ray sources in the ring, the generally harder X-ray color of
the ring sources, the overabundance of luminous sources in the combined XLF,
and the flatter shape of the ring XLF.Comment: 15 pages, 11 figures. Accepted for publication in Ap
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