368 research outputs found
Technical Analysis and Treatment of a Folk Art Portrait of a Boy
This Masterâs Project is a multidisciplinary technical study and conservation treatment of Portrait of a Boy, a 19th century oil painting on canvas and thought to be an example of the American Folk Art movement. Research into Folk Art traditions was executed to inform the context of the artwork. Comprehensive imaging and scientific analyses provided additional historical and material context for the painting. The painting was imaged with the following techniques: visible illumination, ultraviolet (UV) reflectography, ultraviolet-induced visible fluorescence, infrared reflectography, visible-induced infrared (IR) luminescence, x-radiography, and multispectral imaging (MSI). Scientific and materials analyses included: optical microscopy of fiber and paint cross-section samples, x-ray fluorescence spectroscopy (XRF), Fouriertransform infrared spectroscopy (FTIR), and pyrolysis gas chromatography-mass spectroscopy (Py-GCMS). The historical and technical research informed an extensive treatment of the painting, including varnish removal, tear repair, lining, and inpainting. The conservation treatment was successful and resulted in a stabilized painting that more accurately depicts the sitter as well as preserves the painting\u27s materials and composition
Co-doping red-emitting Sr2Si5N8:Eu2+ into yellow-emitting phosphor-packaging for enhancing the optical properties of the 8500 K remote-phosphor packaging wleds
In the last decades, WLEDs attract more and more consideration in both academic and industrial purposes because of its advantages such as fast response time, environment friendliness, small size, long lifetime, and high efficiency. In this research, by doping the red-emitting Sr2Si5N8:Eu2+ phosphor particles into yellow-emitting YAG:Ce phosphor-packaging, a new recommendation for enhancing the optical properties (color uniformity, color rendering index, and lumen output) of the 8500 K remote-phosphor packaging WLEDs is presented, investigated, and demonstrated. By using Mat Lab and Light Tools software based on Mie Theory, the obtained results show that the optical properties of the 8500 K remote-phosphor packaging WLEDs significantly depended on Sr2Si5N8:Eu2+ concentration. The results have provided a potential practical recommendation for manufacturing remote-phosphor W-LEDs.Web of Science1341034102
How Digital Natives Learn and Thrive in the Digital Age: Evidence from an Emerging Economy
As a generation of âdigital natives,â secondary students who were born from 2002 to 2010 have various approaches to acquiring digital knowledge. Digital literacy and resilience are crucial for them to navigate the digital world as much as the real world; however, these remain under-researched subjects, especially in developing countries. In Vietnam, the education system has put considerable effort into teaching students these skills to promote quality education as part of the United Nations-defined Sustainable Development Goal 4 (SDG4). This issue has proven especially salient amid the COVIDâ19 pandemic lockdowns, which had obliged most schools to switch to online forms of teaching. This study, which utilizes a dataset of 1061 Vietnamese students taken from the United Nations Educational, Scientific, and Cultural Organization (UNESCO)âs âDigital Kids Asia Pacific (DKAP)â project, employs Bayesian statistics to explore the relationship between the studentsâ background and their digital abilities. Results show that economic status and parentsâ level of education are positively correlated with digital literacy. Students from urban schools have only a slightly higher level of digital literacy than their rural counterparts, suggesting that school location may not be a defining explanatory element in the variation of digital literacy and resilience among Vietnamese students. Studentsâ digital literacy and, especially resilience, also have associations with their gender. Moreover, as students are digitally literate, they are more likely to be digitally resilient. Following SDG4, i.e., Quality Education, it is advisable for schools, and especially parents, to seriously invest in creating a safe, educational environment to enhance digital literacy among students
Crohn's Disease Associated with Sweet's Syndrome and SjĂśgren's Syndrome Treated with Infliximab
The association of Crohn's disease (CD) and Sweet's syndrome is rare and
the presence of SjĂśgren's syndrome in Crohn's disease is even rarer, with only
three reports found in the literature. We describe two cases of Crohn's disease
associated with Sweet's syndrome, one of which is the first case of CD and
Sweet's concomitantly associated with SjĂśgren's syndrome. Both cases
responded rapidly to Infliximab therapy with complete resolution of the skin lesions
Forages Improve Livelihoods of Smallholder Farmers with Beef Cattle in South Central Coastal Vietnam
In South Central Coastal Vietnam, on-farm research and farmer experience demonstrated the benefits of growing improved forages as a means of improving the year round quantity and quality of feed available for beef cattle. In Binh Dinh, Phu Yen and Ninh Thuan provinces, five new forage species (Panicum maximum, cv. TD58, Brachiaria hybrid cv. Mulato II, Pennisetum purpureum cv.VA06, Paspalum atratum cv. Terenos and Stylosanthes guianensis cv. CIAT 184) were evaluated for yield and crude protein concentration. There was not a consistent yield difference between locations for the forage grasses, but in Binh Dinh province P. maximum TD58 produced the highest yield. The grasses were comparable in crude protein concentration. Stylo CIAT 184 performed relatively well and had the highest crude protein concentration. All species have potential use, depending on the circumstances and site factors such as fertility, drainage and availability of irrigation. This work was expanded to a total of 45 farmers to gain feedback on farmer experience in growing different forages. The percentage of farmers who âlikedâ the introduced forages was Mulato II, 92%; TD58, 85%; VA06, 82%; Paspalum, 46%; and Stylo, 36%. By far the most important early socio-economic impact of developing perennial forage plots close to households was an average 50% reduction in the amount of labour and time that farmers spend supplying cut and carry forage to their animals. In addition, the growing of forages can meaningfully reduce the grazing pressure on common grazing lands, thereby lowering the potential for environmental degradation
Sublinear time algorithms for earth mover's distance
We study the problem of estimating the Earth Moverâs Distance (EMD) between probability distributions
when given access only to samples of the distributions. We give closeness testers and additive-error
estimators over domains in [0, 1][superscript d], with sample complexities independent of domain size â permitting
the testability even of continuous distributions over infinite domains. Instead, our algorithms depend on
other parameters, such as the diameter of the domain space, which may be significantly smaller. We also
prove lower bounds showing the dependencies on these parameters to be essentially optimal. Additionally,
we consider whether natural classes of distributions exist for which there are algorithms with better
dependence on the dimension, and show that for highly clusterable data, this is indeed the case. Lastly,
we consider a variant of the EMD, defined over tree metrics instead of the usual l 1 metric, and give tight
upper and lower bounds
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