30,802 research outputs found
Two monotonic functions involving gamma function and volume of unit ball
In present paper, we prove the monotonicity of two functions involving the
gamma function and relating to the -dimensional volume of the
unit ball in .Comment: 7 page
Improving Resource Efficiency with Partial Resource Muting for Future Wireless Networks
We propose novel resource allocation algorithms that have the objective of
finding a good tradeoff between resource reuse and interference avoidance in
wireless networks. To this end, we first study properties of functions that
relate the resource budget available to network elements to the optimal utility
and to the optimal resource efficiency obtained by solving max-min utility
optimization problems. From the asymptotic behavior of these functions, we
obtain a transition point that indicates whether a network is operating in an
efficient noise-limited regime or in an inefficient interference-limited regime
for a given resource budget. For networks operating in the inefficient regime,
we propose a novel partial resource muting scheme to improve the efficiency of
the resource utilization. The framework is very general. It can be applied not
only to the downlink of 4G networks, but also to 5G networks equipped with
flexible duplex mechanisms. Numerical results show significant performance
gains of the proposed scheme compared to the solution to the max-min utility
optimization problem with full frequency reuse.Comment: 8 pages, 9 figures, to appear in WiMob 201
Renormalization of the EWCL and its Application to LEP2
We perform a systematic one-loop renormalization on the electroweak chiral
Lagrangian (EWCL) up to operators and construct the renormalization
group equations (RGE) for the anomalous couplings. We examine the impact of the
triple gauge coupling (TGC) measurement from LEP2 to the uncertainty of the
parameter at the , and find that the uncertainty in the
TGC measurements can shift at least .Comment: 4 pages, 1 eps figure, uses ws-ijmpa.cls. Paralell talk given at
"International Conference on QCD and hadronic Physics", Beijing, China, 16-20
June, 200
Diffusion Models for Double-ended Queues with Renewal Arrival Processes
We study a double-ended queue where buyers and sellers arrive to conduct
trades. When there is a pair of buyer and seller in the system, they
immediately transact a trade and leave. Thus there cannot be non-zero number of
buyers and sellers simultaneously in the system. We assume that sellers and
buyers arrive at the system according to independent renewal processes, and
they would leave the system after independent exponential patience times. We
establish fluid and diffusion approximations for the queue length process under
a suitable asymptotic regime. The fluid limit is the solution of an ordinary
differential equation, and the diffusion limit is a time-inhomogeneous
asymmetric Ornstein-Uhlenbeck process (O-U process). A heavy traffic analysis
is also developed, and the diffusion limit in the stronger heavy traffic regime
is a time-homogeneous asymmetric O-U process. The limiting distributions of
both diffusion limits are obtained. We also show the interchange of the heavy
traffic and steady state limits
Low-Shot Learning with Imprinted Weights
Human vision is able to immediately recognize novel visual categories after
seeing just one or a few training examples. We describe how to add a similar
capability to ConvNet classifiers by directly setting the final layer weights
from novel training examples during low-shot learning. We call this process
weight imprinting as it directly sets weights for a new category based on an
appropriately scaled copy of the embedding layer activations for that training
example. The imprinting process provides a valuable complement to training with
stochastic gradient descent, as it provides immediate good classification
performance and an initialization for any further fine-tuning in the future. We
show how this imprinting process is related to proxy-based embeddings. However,
it differs in that only a single imprinted weight vector is learned for each
novel category, rather than relying on a nearest-neighbor distance to training
instances as typically used with embedding methods. Our experiments show that
using averaging of imprinted weights provides better generalization than using
nearest-neighbor instance embeddings.Comment: CVPR 201
Octupolar Tensors for Liquid Crystals
A third-order three-dimensional symmetric traceless tensor, called the
\emph{octupolar} tensor, has been introduced to study tetrahedratic nematic
phases in liquid crystals. The octupolar \emph{potential}, a scalar-valued
function generated on the unit sphere by that tensor, should ideally have four
maxima capturing the most probable molecular orientations (on the vertices of a
tetrahedron), but it was recently found to possess an equally generic variant
with \emph{three} maxima instead of four. It was also shown that the
irreducible admissible region for the octupolar tensor in a three-dimensional
parameter space is bounded by a dome-shaped surface, beneath which is a
\emph{separatrix} surface connecting the two generic octupolar states. The
latter surface, which was obtained through numerical continuation, may be
physically interpreted as marking a possible \emph{intra-octupolar} transition.
In this paper, by using the resultant theory of algebraic geometry and the
E-characteristic polynomial of spectral theory of tensors, we give a
closed-form, algebraic expression for both the dome-shaped surface and the
separatrix surface. This turns the envisaged intra-octupolar transition into a
quantitative, possibly observable prediction. Some other properties of
octupolar tensors are also studied
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Ecological thresholds and large carnivores conservation: Implications for the Amur tiger and leopard in China
The ecological threshold concept describes how changes in one or more factors at thresholds can result in a large shift in the state of an ecosystem. This concept focuses attention on limiting factors that affect the tolerance of systems or organisms and changes in them. Accumulating empirical evidence for the existence of ecological thresholds has created favorable conditions for practical application to wildlife conservation. Applying the concept has the potential to enhance conservation of two large carnivores, Amur tiger and leopard, and the knowledge gained could guide the construction of a proposed national park. In this review, ecological thresholds that result from considering a paradigm of bottom-up control were evaluated for their potential to contribute to the conservation of Amur tiger and leopard. Our review highlights that large carnivores, as top predators, are potentially affected by ecological thresholds arising from changes in climate (or weather), habitat, vegetation, prey, competitors, and anthropogenic disturbances. What's more, interactions between factors and context dependence need to be considered in threshold research and conservation practice, because they may amplify the response of ecosystems or organisms to changes in specific drivers. Application of the threshold concept leads to a more thorough evaluation of conservation needs, and could be used to guide future Amur tiger and leopard research and conservation in China. Such application may inform the conservation of other large carnivores worldwide
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