1,227 research outputs found
A usability evaluation of the prototype Afrikaanse idiome-woordeboek
The Afrikaanse idiome-woordeboek is a prototype e-dictionary of Afrikaans fixed expres-sions developed with the intention to test the functionalities of the e-dictionary. This dictionary is based on the function theory of lexicography. The e-dictionary makes use of various technologies. When digital tools are developed it is important to consider the usability of the tool. Usability evaluation was done on the Afrikaanse idiome-woordeboek to determine with what success it can be used. Discount usability methods, viz. heuristic evaluation and usability testing were used. This article reports on the findings from the usability tests which are discussed under the categories of content, information architecture, navigation, access (searching and browsing), help, customisation and the use of innovative technologies to manage data in e-dictionaries for search and display. The usability evaluation showed that the users did not always use the e-dictionary as the designers intended. Various recommendations are made to the designers of the Afrikaanse idiome-woordeboek, as well as for the design of e-dictionaries in general. Recommendations appropriate to e-dictionaries in general are made regarding usability evaluation, information architecture, searching in e-dic-tionaries, the data that can be included in e-dictionaries and training of users of e-dictionaries. Keywords: E-Dictionaries, Online Dictionaries, Electronic Dictionaries, Usability Evaluation, Usability Tests, Discount Usability, Dictionary Literacy
Collineation group as a subgroup of the symmetric group
Let be the projectivization (i.e., the set of one-dimensional vector
subspaces) of a vector space of dimension over a field. Let be a
closed (in the pointwise convergence topology) subgroup of the permutation
group of the set . Suppose that contains the
projective group and an arbitrary self-bijection of transforming a
triple of collinear points to a non-collinear triple. It is well-known from
\cite{KantorMcDonough} that if is finite then contains the
alternating subgroup of .
We show in Theorem \ref{density} below that , if
is infinite.Comment: 9 page
A Cohort Study to Determine the Epidemiology of Estuary-Associated Syndrome
From the Introduction:
Estuary-Associated Syndrome (EAS) is the name given to a potential illness characterized primarily by changes in an individual\u27s cognitive abilities, including acute onset of memory loss or the sudden inability to solve simple problems. Other possible signs of illness include respiratory symptoms, skin rash, or gastrointestinal distress. This illness appears to arise following exposure to toxin produced by Pfiesteria piscicida, or other toxic dinoflagellates, that resides in estuary waters.
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In order to learn more about this possible syndrome and to determine if a causal relationship exists between association to waters containing Pfiesteria or other toxic PLOs and illness, cohort studies in Maryland, North Carolina and Virginia were funded by the Centers for Disease Control and Prevention (CDC). In Virginia, CDC funding through VDH supports the study being done by the Survey and Evaluation Research Laboratory (SERL) at Virginia Commonwealth University with assistance from researchers at the Medical College of Virginia/Virginia Commonwealth University, Eastern Virginia Medical School and the University of Virginia. This study is being conducted in collaboration with researchers at Old Dominion University (ODU), the Virginia Institute of Marine Science (VIMS) and the Department of Environmental Quality (DEQ) who are gathering information on the environmental aspects of Virginia\u27s waters. The objectives of the study include:
1. Determine the association between exposure to estuary waters containing PLOs and possible EAS. 2. Characterize the clinical signs and symptoms of EAS. 3. Determine the incidence and prevalence of EAS. 4. Identify risk factors and exposure conditions required for illness
Soil radium, soil gas radon and indoor radon empirical relationships to assist in post-closure impact assessment related to near-surface radioactive waste disposal
Least squares (LS), Theilâs (TS) and weighted total least squares (WTLS) regression analysis methods are used to develop empirical relationships between radium in the ground, radon in soil and radon in dwellings to assist in the post-closure assessment of indoor radon related to near-surface radioactive waste disposal at the Low Level Waste Repository in England. The data sets used are (i) estimated 226Ra in the <2 mm fraction of topsoils (eRa226) derived from equivalent uranium (eU) from airborne gamma spectrometry data, (ii) eRa226 derived from measurements of uranium in soil geochemical samples, (iii) soil gas radon and (iv) indoor radon data. For models comparing indoor radon and (i) eRa226 derived from airborne eU data and (ii) soil gas radon data, some of the geological groupings have significant slopes. For these groupings there is reasonable agreement in slope and intercept between the three regression analysis methods (LS, TS and WTLS). Relationships between radon in dwellings and radium in the ground or radon in soil differ depending on the characteristics of the underlying geological units, with more permeable units having steeper slopes and higher indoor radon concentrations for a given radium or soil gas radon concentration in the ground. The regression models comparing indoor radon with soil gas radon have intercepts close to 5 Bq mâ3 whilst the intercepts for those comparing indoor radon with eRa226 from airborne eU vary from about 20 Bq mâ3 for a moderately permeable geological unit to about 40 Bq mâ3 for highly permeable limestone, implying unrealistically high contributions to indoor radon from sources other than the ground. An intercept value of 5 Bq mâ3 is assumed as an appropriate mean value for the UK for sources of indoor radon other than radon from the ground, based on examination of UK data. Comparison with published data used to derive an average indoor radon: soil 226Ra ratio shows that whereas the published data are generally clustered with no obvious correlation, the data from this study have substantially different relationships depending largely on the permeability of the underlying geology. Models for the relatively impermeable geological units plot parallel to the average indoor radon: soil 226Ra model but with lower indoor radon: soil 226Ra ratios, whilst the models for the permeable geological units plot parallel to the average indoor radon: soil 226Ra model but with higher than average indoor radon: soil 226Ra ratios
Next--to--Leading Order Corrections to Meson Masses in the Heavy Quark Effective Theory
We use the QCD sum rule approach to calculate the splitting between vector
and pseudoscalar mesons containing one light and one heavy quark, and the
kinetic energy of the heavy quark. Our result for the splitting induced by the
chromomagnetic interaction agrees to the experimental data on charm and beauty
mesons. For the matrix element of the kinetic energy operator, we obtain the
value .Comment: 33 ps., PS figures included, requires REVTEX.3 and psfig,
TUM-T31-42/93/R (additional contribution to kinetic energy taken into
account, marginal changes in the results
Critical Statistical Charge for Anyonic Superconductivity
We examine a criterion for the anyonic superconductivity at zero temperature
in Abelian matter-coupled Chern-Simons gauge field theories in three
dimensions. By solving the Dyson-Schwinger equations, we obtain a critical
value of the statistical charge for the superconducting phase in a massless
fermion-Chern-Simons model.Comment: 11 pages; to appear in Phys Rev
Analyticity Properties and Unitarity Constraints of Heavy Meson Form Factors
We derive new bounds on the b-number form factor of the B meson.
(Revised version of hep-ph/9306214).Comment: 22 page
A global map to aid the identification and screening of critical habitat for marine industries
Marine industries face a number of risks that necessitate careful analysis prior to making decisions on the siting of operations and facilities. An important emerging regulatory framework on environmental sustainability for business operations is the International Finance Corporationâs Performance Standard 6 (IFC PS6). Within PS6, identification of biodiversity significance is articulated through the concept of âCritical Habitatâ, a definition developed by the IFC and detailed through criteria aligned with those that support internationally accepted biodiversity designations. No publicly available tools have been developed in either the marine or terrestrial realm to assess the likelihood of sites or operations being located within PS6-defined Critical Habitat. This paper presents a starting point towards filling this gap in the form of a preliminary global map that classifies more than 13 million km2 of marine and coastal areas of importance for biodiversity (protected areas, Key Biodiversity Areas [KBA], sea turtle nesting sites, cold- and warm-water corals, seamounts, seagrass beds, mangroves, saltmarshes, hydrothermal vents and cold seeps) based on their overlap with Critical Habitat criteria, as defined by IFC. In total, 5798Ă103 km2 (1.6%) of the analysis area (global ocean plus coastal land strip) were classed as Likely Critical Habitat, and 7526Ă103 km2 (2.1%) as Potential Critical Habitat; the remainder (96.3%) were Unclassified. The latter was primarily due to the paucity of biodiversity data in marine areas beyond national jurisdiction and/or in deep waters, and the comparatively fewer protected areas and KBAs in these regions. Globally, protected areas constituted 65.9% of the combined Likely and Potential Critical Habitat extent, and KBAs 29.3%, not accounting for the overlap between these two features. Relative Critical Habitat extent in Exclusive Economic Zones varied dramatically between countries. This work is likely to be of particular use for industries operating in the marine and coastal realms as an early screening aid prior to in situ Critical Habitat assessment; to financial institutions making investment decisions; and to those wishing to implement good practice policies relevant to biodiversity management. Supplementary material (available online) includes other global datasets considered, documentation and justification of biodiversity feature classification, detail of IFC PS6 criteria/scenarios, and coverage calculations
Unitarity Constraints on the B and B^* Form Factors from QCD Analyticity and Heavy Meson Spin Symmetry
A method of deriving bounds on the weak meson form factors, based on
perturbative QCD, analyticity and unitarity, is generalized in order to fully
exploit heavy quark spin symmetry in the ground state doublet of
pseudoscalar and vector mesons. All the relevant form factors of
these mesons are taken into account in the unitarity sum. They are treated as
independent functions along the timelike axis, being related by spin symmetry
only near the zero recoil point. Heavy quark vacuum polarisation up to three
loops in perturbative QCD and the experimental cross sections are used as input. We obtain bounds on the charge radius
of the elastic form factor of the meson, which considerably improve
previous results derived in the same framework.Comment: 13 pages LaTex, 1 figure as a separate ps fil
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