5,844 research outputs found
Recommended from our members
A tale of one city: intra-institutional variations in migrating VLE platform
City University London committed in 2009 to make Moodle the Virtual Learning Environment (VLE) at the core of a new Strategic Learning Environment (SLE) comprised of VLE, externally facing website and related systems such as video streaming and virtual classrooms. Previously, the WebCT VLE had been separate from most of the other systems at the institution with very limited connections to other tools. Each of the schools within the institution was able to pursue their own strategy and timeframe for the migration and embedding of Moodle within their subject areas, within an absolute limit of 2 years. This paper outlines the approaches taken by the various schools, highlighting similarities and differences, and draws out common aspects from the project to make recommendations for institutions seeking to undertake similar migrations
The Kinetic Activation-Relaxation Technique: A Powerful Off-lattice On-the-fly Kinetic Monte Carlo Algorithm
Many materials science phenomena, such as growth and self-organisation, are
dominated by activated diffusion processes and occur on timescales that are
well beyond the reach of standard-molecular dynamics simulations. Kinetic Monte
Carlo (KMC) schemes make it possible to overcome this limitation and achieve
experimental timescales. However, most KMC approaches proceed by discretizing
the problem in space in order to identify, from the outset, a fixed set of
barriers that are used throughout the simulations, limiting the range of
problems that can be addressed. Here, we propose a more flexible approach --
the kinetic activation-relaxation technique (k-ART) -- which lifts these
constraints. Our method is based on an off-lattice, self-learning, on-the-fly
identification and evaluation of activation barriers using ART and a
topological description of events. The validity and power of the method are
demonstrated through the study of vacancy diffusion in crystalline silicon.Comment: 5 pages, 4 figure
Power grids vulnerability: a complex network approach
Power grids exhibit patterns of reaction to outages similar to complex
networks. Blackout sequences follow power laws, as complex systems operating
near a critical point. Here, the tolerance of electric power grids to both
accidental and malicious outages is analyzed in the framework of complex
network theory. In particular, the quantity known as efficiency is modified by
introducing a new concept of distance between nodes. As a result, a new
parameter called net-ability is proposed to evaluate the performance of power
grids. A comparison between efficiency and net-ability is provided by
estimating the vulnerability of sample networks, in terms of both the metrics.Comment: 16 pages, 3 figures. Figure 2 and table II modified. Typos corrected.
Version accepted for publication in Chao
Design, development and delivery of one /1/ breadboard and three /3/ production units of a 75 VA integrated static inverter Monthly progress report no. 11, Mar. 1966
Breadboard model development of integrated static inverte
Contribution of Scalar Loops to the Three-Photon Decay of the Z
I corrected 3 mistakes from the first version: that were an omitted Feynman
integration in the function f^3_{ij}, a factor of 2 in front of log f^3_{ij} in
eq.2 and an overall factor of 2 in Fig.1 c). The final result is changed
drastically. Doing an expansion in the Higgs mass I show that the matrix
element is identically 0 in the order (MZ/MH)^2, which is due to gauge
invariance. Left with an amplitude of the order (MZ/MH)^4 the final result is
that the scalar contribution to this decay rate is several orders of magnitude
smaller than those of the W boson and fermions.Comment: 6 pages, plain Tex, 1 figure available under request via fax or mail,
OCIP/C-93-5, UQAM-PHE-93/0
Design, development and delivery of one /1/ breadboard and three /3/ production units of a 75 VA integrated static inverter Monthly report no. 15
Flip-flop arrays, power transistors, epitaxial stress, and other technological developments in integrated static inverter progra
Global Optimization by Energy Landscape Paving
We introduce a novel heuristic global optimization method, energy landscape
paving (ELP), which combines core ideas from energy surface deformation and
tabu search. In appropriate limits, ELP reduces to existing techniques. The
approach is very general and flexible and is illustrated here on two protein
folding problems. For these examples, the technique gives faster convergence to
the global minimum than previous approaches.Comment: to appear in Phys. Rev. Lett. (2002
Performance and Acceptability of Legume-Fortified Yam Flours
Yam (Dioscoreasp.) is an annual climbing plant with edible underground tubers which is a major staple of many African and Asian countries. About 52 million tonnes of yam was produced globally in 2007, with 96% from West African (IITA, 2009). Yam has the highest calories provided per hectare when compared with other starchy tubers such as cassava and potatoes. Yam is rich in carbohydrates, dietary fibre and some minerals. Yams are usually consumed boiled, roasted, fried or pounded. The tubers are stored in-between harvests for later use which is characterized by changes in wholesomeness which may result from poor handling, wound repair, diseases, and pests infestations. Also due to its high moisture content (50- 80%), large size, and high respiration rates, it is highly perishable. Hence yam tubers are lost after 4-5 months of storage, thus causing a yearly cycle of huge post- harvest losses. In Ghana, post- harvest losses of yam have been reported to range from 10% to 50%. Although West Africa produces about 94% of the world’s yam, yams have not been processed to any significant extent commercially. However due to similarity in composition of yam to crops like potato,yams could be processed into ready to eat foods like chips, crisps flakes and fries to increase their commercial value. They can also be processed into flours for instant foods (e.g. porridge, fufu, mpotonpoton (yam porridge that is spiced with palm oil added)). Fortifying yam flours with legumes such as soyabean and cowpeas could further enhance their commercial value as the fortified products could be used for complementary feeding. This study therefore developed legume-fortified yam flours to enhance their nutritional level as well as extend the shelf-life of yam. The results showed that the blends were acceptable to trained sensory panellists at baseline and also at six months. The products were also nutritionally enhanced, and could therefore be used for complementary feeding. Keywords:Yams, Post-harvest Losses, Value-addition, Legume-fortified flour
The Boson Loop Background to H -> ZZ at Photon-photon Colliders
We have performed a complete one-loop calculation of in the Standard Model, including both gauge bosons and fermions
in the loop. We confirm the large irreducible continuum background from the
-boson loop found by Jikia. We have included the photon-photon luminosity,
and find that the continuum background of transverse boson pairs prohibits
finding a heavy Higgs with mass \gtap 350 GeV in this decay mode.Comment: 16 pages + 4 PS figures included (uuencoded), MAD/PH/77
- …