1,085 research outputs found
Morphing of âflyingâ shapes for autonomous underwater and aerial vehicles
Autonomous vehicles are energy poor and should be designed to minimise the power required to propel
them throughout their mission. The University of Southamptonâs School of Engineering Sciences is
actively involved in the development of improved designs for aerial and maritime autonomous vehicles.
The ability to adapt or âmorphâ their shape in-flight offers an opportunity to extend mission
range/duration and improve agility. The practical implementation of such systems at small scale requires
detailed consideration of the number, mass and power requirements of the individual actuation elements.
Three approaches for minimising actuation requirements are considered. The first uses a combination of
push-pull actuators coupled with a snap-through composite lay-up to achieve alterations in shape. It is
proposed that such a system could be applied to the trailing edge of an autonomous underwater glider
wing instead of the more usual servo operated trailing edge flap. The anisotropy achieved through use of
different composite ply orientations and stacking can also be used to generate bend-twist coupling such
that fluid dynamic loads induce âpassiveâ shape adaptation. The third approach uses a detailed
understanding of the structural response of buckled elements to applied control moments to deform a
complete wing. At this stage of the research no definitive conclusions have been drawn other than that all
three approaches show sufficient promise and can now be applied to one of the autonomous vehicles
Law Schools as Knowledge Centers in the Digital Age
This article explores what it would mean for law schools to be âknowledge centersâ in the digital age, and to have this as a central mission. It describes the activities of legal knowledge centers as: (1) focusing on solving real legal problems in society outside of the academy; (2) evaluating the problem-solving effectiveness of the legal knowledge being developed; (3) re-conceptualizing the structures used to represent legal knowledge, the processes through which legal knowledge is created, and the methods used to apply that knowledge; and (4) disseminating legal knowledge in ways that assist its implementation. The Article uses as extended examples of knowledge centers in the digital age the research laboratories in the sciences, and in particular research laboratories in linguistics and information science. It uses numerous examples to suggest how law schools might implement the concept of a knowledge center
Law Schools as Knowledge Centers in the Digital Age
This article explores what it would mean for law schools to be âknowledge centersâ in the digital age, and to have this as a central mission. It describes the activities of legal knowledge centers as: (1) focusing on solving real legal problems in society outside of the academy; (2) evaluating the problem-solving effectiveness of the legal knowledge being developed; (3) re-conceptualizing the structures used to represent legal knowledge, the processes through which legal knowledge is created, and the methods used to apply that knowledge; and (4) disseminating legal knowledge in ways that assist its implementation. The Article uses as extended examples of knowledge centers in the digital age the research laboratories in the sciences, and in particular research laboratories in linguistics and information science. It uses numerous examples to suggest how law schools might implement the concept of a knowledge center
Social Impact
From the Dean: Remember the Past. Imagine the Future. Celebrate Today.;
Perspectives: Temperature Rising: Health Care Reform is Back;
Bookshelf: From Incentives to Intuition: What Faculty and Staff are Reading.;
Perspectives with Melissa Jonson-Reid & Brett Drake: Changing the Role of Child Welfare; Perspectives: SEED for Oklahoma Kids.;
Interview: Q&A with Julian Le Grand;
Connecting Individual Health with Public Health: New interdisciplinary approaches are needed to solve today\u27s health care challenges. The solution lies at the nexus of social work, public health, and medicine.;
The Green Dream: The social work profession has been slow to engage the issue of environmental justice, but a student-led initiative may spark new interest.;
Serving Soldiers: The needs of returning veterans have changed, which has opened opportunities for new collaborations between schools of social work and the Department of Veterans Affairs.;
Notebook: Research: Examining and identifying barriers to type 2 diabetes management among adolescents, key to reducing risk of complications; Notebook: Research: Study shows autism symptoms can improve into adulthood.; Notebook: Faculty News;
Notebook: Events;
Celebrate Our Histor
Implications of the Top Quark Mass Measurement for the CKM Parameters, and CP Asymmetries
Motivated by the recent determination of the top quark mass by the CDF
collaboration, \mt =174 \pm 10 ^{+13}_{-12} GeV, we review and update the
constraints on the parameters of the quark flavour mixing matrix in
the standard model. In performing our fits, we use inputs from the measurements
of the following quantities: (i) \abseps, the CP-violating parameter in
decays, (ii) \delmd, the mass difference due to the \bdbdbar\ mixing, (iii)
the matrix elements \absvcb and \absvub, and (iv) -hadron lifetimes. We
find that the allowed region of the unitarity triangle is very large, mostly
due to theoretical uncertainties. (This emphasizes the importance of
measurements of CP-violating rate asymmetries in the system.) Nevertheless,
the present data do somewhat restrict the allowed values of the coupling
constant product and the renormalization-scale
invariant bag constant . With the updated CKM matrix we present the
currently-allowed range of the ratio , as well as
the standard model predictions for the \bsbsbar\ mixing parameter \xs and the
quantities , and , which characterize
the CP-asymmetries in -decays. The ALEPH collaboration has recently reported
a significant improvement on the lower limit on the \bs-\bsb mass
difference, (95\% C.L.). This has interesting
consequences for the CKM parameters which are also worked out.
NOTE: this is a revised and updated version of our previous paper.Comment: LaTeX, 27 pages, 16 uuencoded figures (enclosed), CERN-TH.7398/94,
UdeM-GPP-TH-94-0
Social Impact
From the Dean: Our Work in this Economy.;
Interview: Q&A with Paul C. Brophy;
Bookshelf: Understanding Assets: Two new books explore the impact of ownership and assets on individuals and communities;
Perspectives with Matthew Kreuter: Communication Connections;
Building a New Paradigm: Transdisciplinary Research Comes to the Forefront;
A Sense of Place: Place-Based Initiatives Help Communities and Students;
Notebook: Research: Tutoring Produces Big Gains in Student Learning;
Notebook: Research: Free Exercise and Nutrition Program in Brazil Could Serve as Model in United States;
Notebook: Research: Growing Problem for Veterans-Domestic Violence;
Notebook: Message of Service Drives Surge in Peace Corps Applications;
Notebook: Research: Black Newspapers Used as Cancer Education Tool in African American Communities;
Notebook: Partnerships: Indian Immersion: 22-day Exchange Offers Insight into Mental Health and Poverty;
Notebook: New on the Web: Creating Community: New Online Resources;
Notebook: Faculty News;
Alumni News and Note
Non-negative mixed finite element formulations for a tensorial diffusion equation
We consider the tensorial diffusion equation, and address the discrete
maximum-minimum principle of mixed finite element formulations. In particular,
we address non-negative solutions (which is a special case of the
maximum-minimum principle) of mixed finite element formulations. The discrete
maximum-minimum principle is the discrete version of the maximum-minimum
principle.
In this paper we present two non-negative mixed finite element formulations
for tensorial diffusion equations based on constrained optimization techniques
(in particular, quadratic programming). These proposed mixed formulations
produce non-negative numerical solutions on arbitrary meshes for low-order
(i.e., linear, bilinear and trilinear) finite elements. The first formulation
is based on the Raviart-Thomas spaces, and is obtained by adding a non-negative
constraint to the variational statement of the Raviart-Thomas formulation. The
second non-negative formulation based on the variational multiscale
formulation.
For the former formulation we comment on the affect of adding the
non-negative constraint on the local mass balance property of the
Raviart-Thomas formulation. We also study the performance of the active set
strategy for solving the resulting constrained optimization problems. The
overall performance of the proposed formulation is illustrated on three
canonical test problems.Comment: 40 pages using amsart style file, and 15 figure
Testing factorization in B -> D(*)X decays
In QCD the amplitude for B0 -> D(*)+pi- factorizes in the large Nc limit or
in the large energy limit Q >> Lambda_QCD where Q = {m_b, m_c, m_b-m_c}. Data
also suggests factorization in exclusive processes B-> D* pi+ pi- pi- pi0 and
B-> D* omega pi-, however by themselves neither large Nc nor large Q can
account for this. Noting that the condition for large energy release in B0-> D+
pi- is enforced by the SV limit, m_b, m_c >> m_b-m_c >> Lambda, we propose that
the combined large Nc and SV limits justify factorization in B -> D(*) X. This
combined limit is tested with the inclusive decay spectrum measured by CLEO. We
also give exact large Nc relations among isospin amplitudes for B -> D(*)X and
B -> D(*) D-bar(*)X, which can be used to test factorization through exclusive
or inclusive measurements. Predictions for the modes B-> D(*) pi pi, B-> D(*)K
K-bar and B-> D(*) D-bar(*) K are discussed using available data.Comment: 15 pages, 3 included .eps figures, minor change
Focused very high-energy electron beams as a novel radiotherapy modality for producing high-dose volumetric elements
The increased inertia of very high-energy electrons (VHEEs) due to relativistic effects reduces scattering and enables irradiation of deep-seated tumours. However, entrance and exit doses are high for collimated or diverging beams. Here, we perform a study based on Monte Carlo simulations of focused VHEE beams in a water phantom, showing that dose can be concentrated into a small, well-defined volumetric element, which can be shaped or scanned to treat deep-seated tumours. The dose to surrounding tissue is distributed over a larger volume, which reduces peak surface and exit doses for a single beam by more than one order of magnitude compared with a collimated beam
Evading the CKM Hierarchy: Intrinsic Charm in B Decays
We show that the presence of intrinsic charm in the hadrons' light-cone wave
functions, even at a few percent level, provides new, competitive decay
mechanisms for B decays which are nominally CKM-suppressed. For example, the
weak decays of the B-meson to two-body exclusive states consisting of strange
plus light hadrons, such as B\to\pi K, are expected to be dominated by penguin
contributions since the tree-level b\to s u\bar u decay is CKM suppressed.
However, higher Fock states in the B wave function containing charm quark pairs
can mediate the decay via a CKM-favored b\to s c\bar c tree-level transition.
Such intrinsic charm contributions can be phenomenologically significant. Since
they mimic the amplitude structure of ``charming'' penguin contributions,
charming penguins need not be penguins at all.Comment: 28 pages, 6 figures, published version. References added, minor
change
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