245,666 research outputs found
Multitarget Tracking in Nonoverlapping Cameras Using a Reference Set
Tracking multiple targets in nonoverlapping cameras are challenging since the observations of the same targets are often separated by time and space. There might be significant appearance change of a target across camera views caused by variations in illumination conditions, poses, and camera imaging characteristics. Consequently, the same target may appear very different in two cameras. Therefore, associating tracks in different camera views directly based on their appearance similarity is difficult and prone to error. In most previous methods, the appearance similarity is computed either using color histograms or based on pretrained brightness transfer function that maps color between cameras. In this paper, a novel reference set based appearance model is proposed to improve multitarget tracking in a network of nonoverlapping cameras. Contrary to previous work, a reference set is constructed for a pair of cameras, containing subjects appearing in both camera views. For track association, instead of directly comparing the appearance of two targets in different camera views, they are compared indirectly via the reference set. Besides global color histograms, texture and shape features are extracted at different locations of a target, and AdaBoost is used to learn the discriminative power of each feature. The effectiveness of the proposed method over the state of the art on two challenging real-world multicamera video data sets is demonstrated by thorough experiments
The impact of charge symmetry and charge independence breaking on the properties of neutrons and protons in isospin-asymmetric nuclear matter
We investigate the effects of charge independence and charge symmetry
breaking in neutron-rich matter. We consider neutron and proton properties in
isospin-asymmetric matter at normal densities as well as the high-density
neutron matter equation of state and the bulk properties of neutron stars. We
find charge symmetry and charge independence breaking effects to be very small.Comment: 6 pages, 8 figure
A biomimetic nanofluidic diode based on surface-modified polymeric carbon nitride nanotubes
A controllable ion transport including ion selectivity and ion rectification across nanochannels or porous membranes is of great importance because of potential applications ranging from biosensing to energy conversion. Here, a nanofluidic ion diode was realized by modifying carbon nitride nanotubes with different molecules yielding an asymmetric surface charge that allows for ion rectification. With the advantages of low-cost, thermal and mechanical robustness, and simple fabrication process, carbon nitride nanotubes with ion rectification have the potential to be used in salinity-gradient energy conversion and ion sensor systems
Minimum Altitude-Loss Soaring in a Specified Vertical Wind Distribution
Minimum altitude-loss flight of a sailplane through a given vertical wind distribution is discussed. The problem is posed as an optimal control problem, and several numerical solutions are obtained for a sinusoidal wind distribution
Quasi-local energy and the choice of reference
A quasi-local energy for Einstein's general relativity is defined by the
value of the preferred boundary term in the covariant Hamiltonian formalism.
The boundary term depends upon a choice of reference and a time-like
displacement vector field (which can be associated with an observer) on the
boundary of the region. Here we analyze the spherical symmetric cases. For the
obvious analytic choice of reference based on the metric components, we find
that this technique gives the same quasi-local energy values using several
standard coordinate systems and yet can give different values in some other
coordinate systems. For the homogeneous-isotropic cosmologies, the energy can
be non-positive, and one case which is actually flat space has a negative
energy. As an alternative, we introduce a way to determine the choice of both
the reference and displacement by extremizing the energy. This procedure gives
the same value for the energy in different coordinate systems for the
Schwarzschild space, and a non-negative value for the cosmological models, with
zero energy for the dynamic cosmology which is actually Minkowski space. The
timelike displacement vector comes out to be the dual mean curvature vector of
the two-boundary.Comment: 21 pages; revised version to appear in CQ
Grid service orchestration using the Business Process Execution Language (BPEL)
Modern scientific applications often need to be distributed across grids. Increasingly
applications rely on services, such as job submission, data transfer or data
portal services. We refer to such services as grid services. While the invocation
of grid services could be hard coded in theory, scientific users want to orchestrate
service invocations more flexibly. In enterprise applications, the orchestration of
web services is achieved using emerging orchestration standards, most notably
the Business Process Execution Language (BPEL). We describe our experience
in orchestrating scientific workflows using BPEL. We have gained this experience
during an extensive case study that orchestrates grid services for the automation of
a polymorph prediction application
From urban to national heat island: The effect of anthropogenic heat output on climate change in high population industrial countries
The project presented here sought to determine whether changes in anthropogenic thermal emission can have a measurable effect on temperature at the national level, taking Japan and Great Britain as type examples. Using energy consumption as a proxy for thermal emission, strong correlations (mean r2 = 0.90 and 0.89, respectively) are found between national equivalent heat output (HO) and temperature above background levels Δt averaged over 5‐ to 8‐yr periods between 1965 and 2013, as opposed to weaker correlations for CMIP5 model temperatures above background levels Δmt (mean r2 = 0.52 and 0.10). It is clear that the fluctuations in Δt are better explained by energy consumption than by present climate models, and that energy consumption can contribute to climate change at the national level on these timescales
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Enhanced forward stimulated Brillouin scattering in silicon photonic slot waveguide Bragg grating
We study the forward stimulated Brillouin scattering process in a suspended silicon slot waveguide Bragg grating. Full-vectorial formalism is applied to analyze the interplay of electrostriction and radiation pressure. We show that radiation pressure is the dominant factor in the proposed waveguide. The Brillouin gain strongly depends on the structural parameters and the maximum value in the order of 106 W−1 m−1 is obtained in the slow light regime, which is more than two orders larger than that of the stand-alone strip and slot waveguides
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