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Acoustic sensor
A method of designing and manufacturing an acoustic sensor having a high degree of directivity is disclosed. The sensor includes a rotatable plate that is attached to a substrate with mounts. In one aspect the mounts are freely rotatable and the torque on the plate is measured using detectors disposed on springs that provide a resistance to rotation of the plate. In another aspect the plate is mounted to the substrate with mounts that torsionally deform during rotation of the plate. These detectors measure the torque on the plate according to the torsional deformation of the mounts. Methods of improving the signal to noise ratio of acoustic sensors having multiple detectors are also disclosed.Board of Regents, University of Texas Syste
Affect - an ethnocentric encounter?: Exploring the 'universalist' imperative of emotional/affectual geographies
No description supplie
Solving the Hierarchy Problem with Exponentially Large Dimensions
In theories with (sets of) two large extra dimensions and supersymmetry in
the bulk, the presence of non-supersymmetric brane defects naturally induces a
logarithmic potential for the volume of the transverse dimensions. Since the
logarithm of the volume rather than the volume itself is the natural variable,
parameters of O(10) in the potential can generate an exponentially large size
for the extra dimensions. This provides a true solution to the hierarchy
problem, on the same footing as technicolor or dynamical supersymmetry
breaking. The area moduli have a Compton wavelength of about a millimeter and
mediate Yukawa interactions with gravitational strength. We present a simple
explicit example of this idea which generates two exponentially large
dimensions. In this model, the area modulus mass is in the millimeter range
even for six dimensional Planck scales as high as 100 TeV.Comment: 13 pages, 7 figures, corrected typo
U(2) and Maximal Mixing of nu_{mu}
A U(2) flavor symmetry can successfully describe the charged fermion masses
and mixings, and supress SUSY FCNC processes, making it a viable candidate for
a theory of flavor. We show that a direct application of this U(2) flavor
symmetry automatically predicts a mixing of 45 degrees for nu_mu to nu_s, where
nu_s is a light, right-handed state. The introduction of an additional flavor
symmetry acting on the right-handed neutrinos makes the model
phenomenologically viable, explaining the solar neutrino deficit as well as the
atmospheric neutrino anomaly, while giving a potential hot dark matter
candidate and retaining the theory's predictivity in the quark sector.Comment: 20 pages, 1 figur
Flavor at the TeV Scale with Extra Dimensions
Theories where the Standard Model fields reside on a 3-brane, with a low
fundamental cut-off and extra dimensions, provide alternative solutions to the
gauge hierarchy problem. However, generating flavor at the TeV scale while
avoiding flavor-changing difficulties appears prohibitively difficult at first
sight. We argue to the contrary that this picture allows us to lower flavor
physics close to the TeV scale. Small Yukawa couplings are generated by
``shining'' badly broken flavor symmetries from distant branes, and flavor and
CP-violating processes are adequately suppressed by these symmetries. We
further show how the extra dimensions avoid four dimensional disasters
associated with light fields charged under flavor. We construct elegant and
realistic theories of flavor based on the maximal U(3)^5 flavor symmetry which
naturally generate the simultaneous hierarchy of masses and mixing angles.
Finally, we introduce a new framework for predictive theories of flavor, where
our 3-brane is embedded within highly symmetrical configurations of
higher-dimensional branes.Comment: 40 pages, 8 figure
Large-Scale Distributed Bayesian Matrix Factorization using Stochastic Gradient MCMC
Despite having various attractive qualities such as high prediction accuracy
and the ability to quantify uncertainty and avoid over-fitting, Bayesian Matrix
Factorization has not been widely adopted because of the prohibitive cost of
inference. In this paper, we propose a scalable distributed Bayesian matrix
factorization algorithm using stochastic gradient MCMC. Our algorithm, based on
Distributed Stochastic Gradient Langevin Dynamics, can not only match the
prediction accuracy of standard MCMC methods like Gibbs sampling, but at the
same time is as fast and simple as stochastic gradient descent. In our
experiments, we show that our algorithm can achieve the same level of
prediction accuracy as Gibbs sampling an order of magnitude faster. We also
show that our method reduces the prediction error as fast as distributed
stochastic gradient descent, achieving a 4.1% improvement in RMSE for the
Netflix dataset and an 1.8% for the Yahoo music dataset
Leakage of an invagination pancreaticojejunostomy may have an influence on mortality
Purpose: No consensus exists regarding the most effective form of pancreaticojejunostomy (PJ) following pancreaticoduodenectomy (PD).
Methods: Data were gathered through the American College of Surgeons-National Surgical Quality Improvement Program, Pancreatectomy Demonstration Project. A total of 1781 patients underwent a PD at 43 institutions. After appropriate exclusions, 890 patients were analyzed. Patients were divided into duct-to-mucosa (n = 734, 82%) and invagination (n = 156, 18%) groups and were compared by unadjusted analysis. Type of PJ was included in eight separate morbidity and mortality multivariable analyses.
Results: Invagination patients had higher serum albumin (p < 0.01) and lower body mass index (p < 0.01), were less likely to have a preoperative biliary stent (p < 0.01), and were more likely to have a soft gland (p < 0.01). PJ anastomosis type was not associated with morbidity but was associated with mortality (duct-to-mucosa vs. invagination, odds ratio = 0.22, p < 0.01). Among patients who developed a clinically relevant pancreatic fistula, none of the 119 duct-to-mucosa, compared with 5 of 21 invagination, patients died (p < 0.01).
Conclusion: Patients who undergo a PJ by duct-to-mucosa or invagination differ with respect to preoperative and intraoperative variables. When an invagination PJ leaks, there may be a greater influence on mortality than when a duct-to-mucosa PJ leaks
Inelastic Dark Matter
Many observations suggest that much of the matter of the universe is
non-baryonic. Recently, the DAMA NaI dark matter direct detection experiment
reported an annual modulation in their event rate consistent with a WIMP relic.
However, the Cryogenic Dark Matter Search (CDMS) Ge experiment excludes most of
the region preferred by DAMA. We demonstrate that if the dark matter can only
scatter by making a transition to a slightly heavier state (Delta m ~ 100kev),
the experiments are no longer in conflict. Moreover, differences in the energy
spectrum of nuclear recoil events could distinguish such a scenario from the
standard WIMP scenario. Finally, we discuss the sneutrino as a candidate for
inelastic dark matter in supersymmetric theories.Comment: 20 pages, 6 figure
Exponentially Small Supersymmetry Breaking from Extra Dimensions
The supersymmetric ``shining'' of free massive chiral superfields in extra
dimensions from a distant source brane can trigger exponentially small
supersymmetry breaking on our brane of order e^{-2 pi R}, where R is the radius
of the extra dimensions. This supersymmetry breaking can be transmitted to the
superpartners in a number of ways, for instance by gravity or via the standard
model gauge interactions. The radius R can easily be stabilized at a size O(10)
larger that the fundamental scale. The models are extremely simple, relying
only on free, classical bulk dynamics to solve the hierarchy problem.Comment: RevTex, 1 figure. Comment on mu problem adde
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