328 research outputs found
A Four-Factor User Interaction Model for Content-Based Image Retrieval
In order to bridge the “Semantic gap”, a number of relevance feedback (RF) mechanisms have been applied to content-based image retrieval (CBIR). However current RF techniques in most existing CBIR systems still lack satisfactory user interaction although some work has been done to improve the interaction as well as the search accuracy. In this paper, we propose a four-factor user interaction model and investigate its effects on CBIR by an empirical evaluation. Whilst the model was developed for our research purposes, we believe the model could be adapted to any content-based search system
A simplified wood combustion model for use in the simulation of cooking fires
Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.Wood combustion was studied with the intention of developing
a simplified model of fuel burn-rate in small cooking fires, for
inclusion in a CFD model of a whole cook-stove. The
investigation included collecting experimental data on fuel
burn-rate, model development and comparison of experimental
and simulation results. In the experimental phase, regular
blocks of wood were arranged in a lattice or crib with a range
of volumes, void fractions and specific surface areas. The
burning cribs yielded 3-40 kW fires. The simplified model
assumed an unreacted core of virgin wood surrounded by char.
It included considerations of heat transfer through the fuel by
conduction; thermal decomposition of the virgin fuel into char
and volatile gases, limited by the supply of heat to the pyrolysis
region; the surface combustion of char limited by the diffusion
of oxygen through the species boundary layer and impeded by
the counter-flow of volatile gases. The model predicted the
change of burn-rate with crib volume, porosity and surface area
shown by experimental data, though it does incur significant
errors, due to the assumption of one-dimensional behaviour
within the crib, and neglecting spatial and temporal variations
in boundary conditions. It was concluded that accuracy of the
model could be improved by developing it to two or three
dimensions, and that the easiest way to do this was through
CFD. The model was sufficiently accurate to be used as a
source of wood volatiles when modelling small fires in cookstoves,
with the aim of investigating the effect of design
changes on stove efficiency.cs201
Diaper dermatitis prevalence and severity : global perspective on the impact of caregiver behavior
Objectives
To compare prevalence and severity of diaper dermatitis (DD) in infants and toddlers (babies) across three countries (China, USA, and Germany), including diapered skin measures and caregiver practices.
Methods
A cross‐sectional study of 1791 babies (~600 from each country) was recruited at each clinical site. Based on regional toilet‐training habits, exclusively diaper‐wearing infants were recruited between ages 2‐8 months in China and 2‐18 months in the USA and Germany. DD was measured, as well as skin pH, transepidermal water loss (TEWL), and relative humidity (RH) in the diapered region. Caregiver habits were collected via a questionnaire and included information on hygienic practices.
Results
Diaper dermatitis was highest in the perianal area, followed by the intertriginous, genital, and buttock regions. In general, DD was significantly lower in babies in China, highest in Germany, and intermediate in the USA. This rank ordering of DD by geography was also observed in baby age 2‐8 months. The lower DD observed in China was associated with lower skin pH and TEWL on diapered skin and decreased RH in the diaper. Chinese caregivers had the highest rate of prophylactic topical product usage, the most robust cleaning of the diapered area, lack of cleansing after urine‐only diaper changes, and Chinese infants spent the least time in an overnight diaper.
Conclusions
These data suggest caregiver behaviors including prophylactic use of topical products, thorough cleaning after stooling and reduced time in an overnight diaper are associated with less DD, lower superficial skin pH, and enhanced skin barrier
Sample preparation with sucrose cryoprotection dramatically alters Zn distribution in the rodent hippocampus, as revealed by elemental mapping
Transition metal ions (Fe, Mn, Cu, Zn) are essential for healthy brain function, but altered concentration, distribution, or chemical form of the metal ions has been implicated in numerous brain pathologies. Currently, it is not possible to image the cellular or sub-cellular distribution of metal ions in vivo and therefore, studying brain-metal homeostasis largely relies on ex vivo in situ elemental mapping. Sample preparation methods that accurately preserve the in vivo elemental distribution are essential if one wishes to translate the knowledge of elemental distributions measured ex vivo toward increased understanding of chemical and physiological pathways of brain disease. The choice of sample preparation is particularly important for metal ions that exist in a labile or mobile form, for which the in vivo distribution could be easily distorted by inappropriate sample preparation. One of the most widely studied brain structures, the hippocampus, contains a large pool of labile and mobile Zn. Herein, we describe how sucrose cryoprotection, the gold standard method of preparing tissues for immuno-histochemistry or immuno-fluorescence, which is also often used as a sample preparation method for elemental mapping studies, drastically alters hippocampal Zn distribution. Based on the results of this study, in combination with a comparison against the strong body of published literature that has used either rapid plunge freezing of brain tissue, or sucrose cryo-protection, we strongly urge investigators in the future to cease using sucrose cryoprotection as a method of sample preparation for elemental mapping, especially if Zn is an analyte of interest
Downgraded curriculum? An analysis of knowledge in new curricula in Scotland and New Zealand
The development, since 2000, of new National Curricula across the Anglophone world signals a number of policy trends, including: a move from the explicit specification of content towards a more generic, skills-based approach; a greater emphasis on the centrality of the learner; and [ostensibly] greater autonomy for teachers in developing the curriculum in school. These policy shifts have attracted some criticism, especially from social realist writers, who claim that the new curricula downgrade knowledge. This paper offers a contribution to this debate; an empirically-based analysis of two new curricula, New Zealand’s Curriculum Framework and Scotland’s Curriculum for Excellence. We conclude that, while these curricula continue to accord considerable importance to knowledge in their statements of policy intent, the social realist critique is at least partially justified, since both curricula are characterised by a lack of coherence and mixed messages about the place of knowledge
Measurement of and charged current inclusive cross sections and their ratio with the T2K off-axis near detector
We report a measurement of cross section and the first measurements of the cross section
and their ratio
at (anti-)neutrino energies below 1.5
GeV. We determine the single momentum bin cross section measurements, averaged
over the T2K -flux, for the detector target material (mainly
Carbon, Oxygen, Hydrogen and Copper) with phase space restricted laboratory
frame kinematics of 500 MeV/c. The
results are and $\sigma(\nu)=\left( 2.41\
\pm0.022{\rm{(stat.)}}\pm0.231{\rm (syst.)}\ \right)\times10^{-39}^{2}R\left(\frac{\sigma(\bar{\nu})}{\sigma(\nu)}\right)=
0.373\pm0.012{\rm (stat.)}\pm0.015{\rm (syst.)}$.Comment: 18 pages, 8 figure
Temporal Vagueness, Coordination and Communication
How is it that people manage to communicate even when they implicitly differ on the meaning of the terms they use? Take an innocent-sounding expression such as tomorrow morning. What counts as morning? There is a surprising amount of variation across different people.
- …