900 research outputs found
Tracing a paradigm for externalization: Avatars and the GPII Nexus
We will situate the concept of an avatar (a working simulacrum of part of a system separated from
it in space or time) with respect to traditional concepts of programming language and systems design.
Whilst much theory and practice argues in favour of insulation (the creation of architectural boundaries
prohibiting the leakage of information) we will find that many successful systems take a diametrically
opposed approach. We name this family of systems as those based on externalised state transfer.
Rather than hiding implementation details behind APIs, object interfaces or similar, these systems actively
advertise their internal structure and its coordinates via data and metadata. Examples of these
systems include RESTful web applications, MIDI devices, and the DWARF debugging file format. We
discuss such systems and how we can purposefully design new systems embodying such virtues in a more
distilled form
Flocking: A framework for declarative music-making on the Web
(Abstract to follow
A Comparison of Petersen Tags and Biological Stains Used With Internal Tags as Marks for Shrimp
During May 20-31, 1968, 14,301 brown shrimp (Penaeus aztecus) were marked and released in Biloxi Bay, Mississippi. Of these 7,023 were marked by injection with a combination of Niagara Sky Blue 6B stain and polyvinyl chloride (PVC) internal tags and 7,278 were marked with Petersen tags. The objectives of this experiment were to compare the two methods as marks for shrimp and to obtain information on growth rates and migrations. Eighteen weeks after release, 1,942 (28%) of those marked with the biological stain-internal tag combination and 2,286 (31%) of those marked with Petersen tags had been recovered. The difference in proportions recaptured (significant at P \u3c0.01) could have resulted from greater ease in recognition of the Petersen tag by commercial fishermen or from differential marking mortality, although no evidence was found that differential marking mortality occurred. Marking mortality was observed for both marks and appeared inversely related to size at time of marking. No significant differences were found between growth rates of shrimp marked with the biological stain-internal tag combination and those of shrimp marked with the Petersen tag, although most weekly average increments for stained shrimp were higher. Rates of return were similar in the vicinity of the release area, although a significantly higher proportion (P \u3c0.01) of returns from waters outside of Biloxi Bay were marked with Petersen tags. Again, this was attributed primarily to greater ease in recognition by commercial fishermen. It was concluded that the Petersen tag was the more effective of the two marks as it appeared to be recognized more readily over longer periods of time than the biological stain
This is Research: Clark: Coding to Learn and Create
Who has the power to create with technology? While coding is increasingly part of educational curricula across Canada, many students with disabilities are being left out. These students often depend on assistive technologies designed by others to participate in class, communicate with family, and share with their friends. They have the most at stake in learning to become producers of their own personal technologies, rather than simply consumers.
The Coding to Learn and Create project, collaboratively led by the research team at the Inclusive Design Research Centre
with Bridges Canada, is co-designing new accessible coding tools and activities alongside learners with disabilities, their teachers, and families. We are researching new forms of visual, audio, and physical programming that can offer greater creative agency to all. Our goal is to help learners create their own digital worlds, express themselves using code and storytelling, and grow their social, learning, and creative capacities. This project is part of a larger research effort to address systemic inequities in computation more broadly. Visit our website at codelearncreate.org to learn more and to participate
Self-consistent description of nuclear compressional modes
Isoscalar monopole and dipole compressional modes are computed for a variety
of closed-shell nuclei in a relativistic random-phase approximation to three
different parametrizations of the Walecka model with scalar self-interactions.
Particular emphasis is placed on the role of self-consistency which by itself,
and with little else, guarantees the decoupling of the spurious
isoscalar-dipole strength from the physical response and the conservation of
the vector current. A powerful new relation is introduced to quantify the
violation of the vector current in terms of various ground-state form-factors.
For the isoscalar-dipole mode two distinct regions are clearly identified: (i)
a high-energy component that is sensitive to the size of the nucleus and scales
with the compressibility of the model and (ii) a low-energy component that is
insensitivity to the nuclear compressibility. A fairly good description of both
compressional modes is obtained by using a ``soft'' parametrization having a
compression modulus of K=224 MeV.Comment: 28 pages and 10 figures; submitted to PR
The CLIMPACTS synthesis report: An assessment of the effects of climate change and variation in New Zealand using the CLIMPACTS system
In the late 1980s, New Zealand undertook the first national assessment of climate change and its possible impacts on the country.The landmark report, reflecting the judgement of scores of national experts, called for greater efforts in building the national research capacity in order to better quantify the range of impacts that could occur in New Zealand from climate change and variability. In response, the collaborative CLIMPACTS Programme was established to provide this capacity. Ten years on from the first national assessment, the present synthesis offers some results from, as well as a demonstration of, the capacity developed by the CLIMPACTS Programme. The purpose of the present document is to provide a summary report from the CLIMPACTS Programme on climate change and its effects on New Zealand.The chapters and their contents are not comprehensive. Rather, they are focused on a specific set of questions, which conform to the particular expertise of the CLIMPACTS Programme members and which employ a limited set of the wide range of tools available within the CLIMPACTS Model. Other important areas such as forests, indigenous ecosystems and pests and diseases are not yet covered
In medium T-matrix for superfluid nuclear matter
We study a generalized ladder resummation in the superfluid phase of the
nuclear matter. The approach is based on a conserving generalization of the
usual T-matrix approximation including also anomalous self-energies and
propagators. The approximation here discussed is a generalization of the usual
mean-field BCS approach and of the in medium T-matrix approximation in the
normal phase. The numerical results in this work are obtained in the
quasi-particle approximation. Properties of the resulting self-energy,
superfluid gap and spectral functions are studied.Comment: 38 pages, 19 figures, Introduction rewritten, Refs. adde
Companions of Stars: From Other Stars to Brown Dwarfs to Planets: The Discovery of the First Methane Brown Dwarf
The discovery of the first methane brown dwarf provides a framework for
describing the important advances in both fundamental physics and astrophysics
that are due to the study of companions of stars. I present a few highlights of
the history of this subject along with details of the discovery of the brown
dwarf Gliese 229B. The nature of companions of stars is discussed with an
attempt to avoid biases induced by anthropocentric nomenclature. With the newer
types of remote reconnaissance of nearby stars and their systems of companions,
an exciting and perhaps even more profound set of contributions to science is
within reach in the near future. This includes an exploration of the diversity
of planets in the universe and perhaps soon the first solid evidence for
biological activity outside our Solar System.Comment: 31 pages, 13 figure
Susceptibility and dilution effects of the kagome bi-layer geometrically frustrated network. A Ga-NMR study of SrCr_(9p)Ga_(12-9p)O_(19)
We present an extensive gallium NMR study of the geometrically frustrated
kagome bi-layer compound SrCr_(9p)Ga_(12-9p)O_(19) (Cr^3+, S=3/2) over a broad
Cr-concentration range (.72<p<.95). This allows us to probe locally the kagome
bi-layer susceptibility and separate the intrinsic properties due to the
geometric frustration from those related to the site dilution. Our major
findings are: 1) The intrinsic kagome bi-layer susceptibility exhibits a
maximum in temperature at 40-50 K and is robust to a dilution as high as ~20%.
The maximum reveals the development of short range antiferromagnetic
correlations; 2) At low-T, a highly dynamical state induces a strong wipe-out
of the NMR intensity, regardless of dilution; 3) The low-T upturn observed in
the macroscopic susceptibility is associated to paramagnetic defects which stem
from the dilution of the kagome bi-layer. The low-T analysis of the NMR
lineshape suggests that the defect can be associated with a staggered
spin-response to the vacancies on the kagome bi-layer. This, altogether with
the maximum in the kagome bi-layer susceptibility, is very similar to what is
observed in most low-dimensional antiferromagnetic correlated systems; 4) The
spin glass-like freezing observed at T_g=2-4 K is not driven by the
dilution-induced defects.Comment: 19 pages, 19 figures, revised version resubmitted to PRB Minor
modifications: Fig.11 and discussion in Sec.V on the NMR shif
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