54 research outputs found
Dataset for Deep learning enabled design of complex transmission matrices for universal optical components
No full textData comprising Numerical simulation results and deep learning results to supprot article N. J. Dinsdale, P. R. Wiecha, M. Delaney, J. Reynolds, M. Ebert, I. Zeimpekis, D. J. Thomson, G. T. Reed, P. Lalanne, K. Vynck, O. L. Muskens "Deep learning enabled design of complex transmission matrices for universal optical components". ACS Photonics (2020). Each figure has a Readme file attached.</span
Temperature dependence of the optical response: Application to bulk GaAs using first-principles molecular dynamics simulations
No full textWe present an approach that takes into account lattice dynamical effects in calculating the optical response of semiconductors by averaging over several perturbed configurations of a supercell extracted from molecular dynamic simulations. The validity of this approach is confirmed by comparing our results for the dielectric function of bulk GaAs in the range of 0 - 700 K with our and other highly accurate ellipsometry measurements. The results of our approach resolve the serious discrepancy in energy and line shape between the latest optical models, all of which neglect lattice dynamics, and experiment
The theme of childhood as a source of inspiration in the works of Arthur Rimbaud and Francois Nourissier
No full textThesis (M.A.) -- University of Stellenbosch, 1999.ENGLISH SUMMARY: The object of this study is to determine the importance of the child's creativity through
the works of 19th century poet, Arthur Rimbaud and the 20th century author, François
Nourissier. An attempt is made to present the child's experiences as a central theme
in the text.
In part one of this thesis, reference is made to Rimbaud's poetry and selected letters,
believed to have been written between 1869 and 1891. The collections Une Saison
en Enter and Les Illuminations, portraying the child in his creative world, are of
importance, along with his masterpiece Le Bateau Ivre (±1871). Themes that refer to
his childhood are emphasized.
In part two, fourteen of François Nourissier's most important novels are discussed,
with specific reference to his autobiographical works. Nourissier believes that his
childhood is responsible for the author he has become.
In part three the childhood of both authors is compared, illustrating some of the most
important themes. It is not common to compare an author's prose with a poet's
poetry, but because of Nourissier's poetic language and similar themes, it is made
possible. Nourissier needs to delve in his past to find fulfilment in his writing as an
adult, while Rimbaud struggles to eternalise the innocence of his childhood in his
poetry.
The conclusion drawn from this study, is that the child's socialisation in his family and
his surroundings will remain deeply rooted in his creative thinking. The author can
use negative experiences with success in his works as a therapy or simply as a
liberating process by sharing his ideas with society. The value of the author and his
writing are often questioned, but when the reader can identify with the text, it can
help him to work with his own creative silences, and to channel these into a positive
creative process. The child that was· exposed to a limited socialisation does not need
to remain a victim of his surroundings, but can freely use his innate creativity as a
gifted artist.AFRIKAANSE OPSOMMING: Die doel van hierdie studie is om die kind se kreatiwiteit uit te lig aan die hand van
die 19de eeuse digter, Arthur Rimbaud en die 20ste eeuse skrywer, François
Nourissier se werke as voorbeeld. Daar word gepoog om die belang van die kind se
ervarings as sentrale tema vir hul teks aan te dui.
In die eerste deel van die tesis word daar na Rimbaud se poesie en geselekteerde
briewe verwys, wat vermoedelik vanaf 1869 tot 1891 geskryf is. Dit is veral sy poesie
in die bundels, Une Saison en Enter en Les Illuminations wat die kind in sy
verbeeldingswereld uitbeeld, wat van belang is, tesame met sy meesterlike gedig Le
Bateau Ivre(± 1871). Temas wat verband hou met sy kinderlewe word beklemtoon.
In die tweede deel word na veertien van François Nourissier se belangrikste boeke
verwys, waaronder die meeste outobiografies van aard is. Nourissier pia as die klem
op sy kinderlewe as inspirasie tot die skrywer wie hy is.
In die derde deel word die twee skrywers se kinderjare vergelyk deur enkele temas
uit te lig. Dit is ongewoon om 'n roman skrywer se werke te vergelyk met die van 'n
digter, maar die poetiese taal en soortgelyke temas van Nourissier maak dit moontlik
om vergelykend hul werk te bestudeer. Nourissier as volwasse skrywer moet delf in
sy verlede om vervulling te vind, terwyl Rimbaud die onskuld van sy kinderjare
probeer verewig in poesie.
Die gevolgtrekking word gemaak dat die kind se sosialisering in sy familie en sy
omgewing, diep gewortel is en sal bly in sy kreatiewe denke. Negatiewe ervarings
kan suksesvol deur die skrywer in sy werke terapeutiese waarde verkry, of dit kan die
skrywer se ervarings aan die samelewing bekend stel as 'n blote bevrydingsproses.
Die waarde van die outeur se skryfkuns word dikwels bevraagteken, maar wanneer
die leser hom met die teks kan identifiseer, kan dit hom help om sy kreatiewe stiltes
te ontgin, en dit tot 'n positiewe skeppingsdrang te omskep. Die kind met 'n beperkte .
sosialisering hoef nie 'n lydende party van sy omgewing te bly nie, maar hy kan dit
vryelik gebruik vir die ontluiking van sy verborge talente.Maste
Seasonal availability of edible underground and aboveground carbohydrate resources to human foragers on the Cape south coast, South Africa
No full textabstract: The coastal environments of South Africa’s Cape Floristic Region (CFR) provide some of the earliest and most abundant evidence for the emergence of cognitively modern humans. In particular, the south coast of the CFR provided a uniquely diverse resource base for hunter-gatherers, which included marine shellfish, game, and carbohydrate-bearing plants, especially those with Underground Storage Organs (USOs). It has been hypothesized that these resources underpinned the continuity of human occupation in the region since the Middle Pleistocene. Very little research has been conducted on the foraging potential of carbohydrate resources in the CFR. This study focuses on the seasonal availability of plants with edible carbohydrates at six-weekly intervals over a two-year period in four vegetation types on South Africa’s Cape south coast. Different plant species were considered available to foragers if the edible carbohydrate was directly (i.e. above-ground edible portions) or indirectly (above-ground indications to below-ground edible portions) visible to an expert botanist familiar with this landscape. A total of 52 edible plant species were recorded across all vegetation types. Of these, 33 species were geophytes with edible USOs and 21 species had aboveground edible carbohydrates. Limestone Fynbos had the richest flora, followed by Strandveld, Renosterveld and lastly, Sand Fynbos. The availability of plant species differed across vegetation types and between survey years. The number of available USO species was highest for a six-month period from winter to early summer (Jul–Dec) across all vegetation types. Months of lowest species’ availability were in mid-summer to early autumn (Jan–Apr); the early winter (May–Jun) values were variable, being highest in Limestone Fynbos. However, even during the late summer carbohydrate “crunch,” 25 carbohydrate bearing species were visible across the four vegetation types. To establish a robust resource landscape will require additional spatial mapping of plant species abundances. Nonetheless, our results demonstrate that plant-based carbohydrate resources available to Stone Age foragers of the Cape south coast, especially USOs belonging to the Iridaceae family, are likely to have comprised a reliable and nutritious source of calories over most of the year.The final version of this article, as published in PeerJ, can be viewed online at: https://peerj.com/articles/1679
THE VIRTUAL TEACHING EXPERIENCE WITH GOOGLE CLASSROOM DURING COVID-19: A PHENOMENOLOGICAL STUDY
No full textTechnology has been the highlight of the 21st century, and its rapid advancement has undeniably changed the world we live in today. The field has been saturated by digital applications (apps) such as Facetime, WhatsApp, GroupMe, and a plethora of educational apps such as Math Series, The Elements, and History Tools. Additional apps have magnified in popularity since the world moved to virtual learning during the COVID-19 pandemic which devastated the global economy and shut down in person education systems around the globe. Google Classroom from G-Suite for Education was immediately embraced to facilitate the educational process allowing students and teachers to continue communication and engagement during the unprecedented COVID-19 global pandemic. According to (Vynck & Bergen, 2020), Google Classroom has double the active users since March 2020, with approximately 100 million users worldwide to date. Google Classroom’s video conference application Meet is being used 25 times more than it was in January of 2020, with a total of 120 million users, up from 90 million in 2019 (Vynck & Bergen, 2020). The purpose of this study was to explore the experiences of teachers using Google Classroom during the COVID-19 pandemic. There were 14 participants from urban and suburban schools in the state of New York, 11 females and 3 males ages 27 through 61, with diverse race and ethnic backgrounds. They taught grades K through 12, diverse student populations, and most held a master’s degree. Using a phenomenological approach, the researcher interviewed each participant on the Zoom platform, engaging them with open ended questions to share their perceptions of virtual teaching. The study analysis revealed six themes which were: The Pros and Cons of Remote Teaching; Cameras and Engagement; “Sink or Swim”: Professional Development to Teach Remotely; I am Not a Techie, But I am Learning; Stress and Disconnect; and Education after COVID-19. This study provides district and school leaders with invaluable information on teacher support and development, parent engagement, closing the digital divide, and the need for social emotional support to address a public health crisis for all to have a healthy mindset moving beyond the COVID-19 pandemic
Bright-white beetle scales optimise multiple scattering of light
No full textThis is the final version of the article. Available from the publisher via the DOI in this record.Error in funder statement in this article is corrected in http://hdl.handle.net/10871/22212Whiteness arises from diffuse and broadband reflection of light typically achieved through optical scattering in randomly structured media. In contrast to structural colour due to coherent scattering, white appearance generally requires a relatively thick system comprising randomly positioned high refractive-index scattering centres. Here, we show that the exceptionally bright white appearance of Cyphochilus and Lepidiota stigma beetles arises from a remarkably optimised anisotropy of intra-scale chitin networks, which act as a dense scattering media. Using time-resolved measurements, we show that light propagating in the scales of the beetles undergoes pronounced multiple scattering that is associated with the lowest transport mean free path reported to date for low-refractive-index systems. Our light transport investigation unveil high level of optimisation that achieves high-brightness white in a thin low-mass-per-unit-area anisotropic disordered nanostructure.We wish to thank R. Blumenfeld, T. Svensson, R. Savo and K. Vynck for fruitful discussions,
B.D. Wilts for the comments on the manuscript and J. Aizenberg for support in the SEM
measurements. The research leading to these results has received funding from the
European Research Council under the European Union’s Seventh Framework Programme
(FP7/2007–2013)/ERC grant agreement n [291349] and USAF grant FA9550-10-1-002
Flexible analysis of digital PCR experiments using generalized linear mixed models
No full textThe use of digital PCR for quantification of nucleic acids is rapidly growing. A major drawback remains the lack of flexible data analysis tools. Published analysis approaches are either tailored to specific problem settings or fail to take into account sources of variability. We propose the generalized linear mixed models framework as a flexible tool for analyzing a wide range of experiments. We also introduce a method for estimating reference gene stability to improve accuracy and precision of copy number and relative expression estimates. We demonstrate the usefulness of the methodology on a complex experimental setup
Le roman et le 'Nouveau roman'
No full textDissertation (M.A.) -- University of Stellenbosch, 1963.Full text to be digitised and attached to bibliographic record
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