22,842 research outputs found
Interacting Multiple Model-Feedback Particle Filter for Stochastic Hybrid Systems
In this paper, a novel feedback control-based particle filter algorithm for
the continuous-time stochastic hybrid system estimation problem is presented.
This particle filter is referred to as the interacting multiple model-feedback
particle filter (IMM-FPF), and is based on the recently developed feedback
particle filter. The IMM-FPF is comprised of a series of parallel FPFs, one for
each discrete mode, and an exact filter recursion for the mode association
probability. The proposed IMM-FPF represents a generalization of the
Kalmanfilter based IMM algorithm to the general nonlinear filtering problem.
The remarkable conclusion of this paper is that the IMM-FPF algorithm retains
the innovation error-based feedback structure even for the nonlinear problem.
The interaction/merging process is also handled via a control-based approach.
The theoretical results are illustrated with the aid of a numerical example
problem for a maneuvering target tracking application
Theory of time-resolved spectral function in high-temperature superconductors with bosonic modes
We develop a three-temperature model to simulate the time dependence of
electron and phonon temperatures in high-temperature superconductors displaying
strong anistropic electron-phonon coupling. This model not only takes the
tight-binding band structure into account, but also is valid in superconducting
state. Based on this model, we calculate the time-resolved spectral function
via the double-time Green's functions. We find that the dip-hump structure
evolves with the time delay. More interestingly, new phononic structures are
obtained when the phonons are excited by a laser field. This signature may
serve as a direct evidence for electron-vibration mode coupling.Comment: 5 pages, 3 figure
Confocal microscopic image sequence compression using vector quantization and 3D pyramids
The 3D pyramid compressor project at the University of Glasgow has developed a compressor for images obtained from CLSM device. The proposed method using a combination of image pyramid coder and vector quantization techniques has good performance at compressing confocal volume image data. An experiment was conducted on several kinds of CLSM data using the presented compressor compared to other well-known volume data compressors, such as MPEG-1. The results showed that the 3D pyramid compressor gave higher subjective and objective image quality of reconstructed images at the same compression ratio and presented more acceptable results when applying image processing filters on reconstructed images
Demonstration of Shor's quantum factoring algorithm using photonic qubits
We report an experimental demonstration of a complied version of Shor's
algorithm using four photonic qubits. We choose the simplest instance of this
algorithm, that is, factorization of N=15 in the case that the period and
exploit a simplified linear optical network to coherently implement the quantum
circuits of the modular exponential execution and semi-classical quantum
Fourier transformation. During this computation, genuine multiparticle
entanglement is observed which well supports its quantum nature. This
experiment represents a step toward full realization of Shor's algorithm and
scalable linear optics quantum computation.Comment: small changes over v2; to appear in PR
Pion Form Factor in the Factorization Formalism
Based on the light-cone (LC) framework and the factorization formalism,
the transverse momentum effects and the different helicity components'
contributions to the pion form factor are recalculated. In
particular, the contribution to the pion form factor from the higher helicity
components (), which come from the spin-space Wigner
rotation, are analyzed in the soft and hard energy regions respectively. Our
results show that the right power behavior of the hard contribution from the
higher helicity components can only be obtained by fully keeping the
dependence in the hard amplitude, and that the dependence in LC wave
function affects the hard and soft contributions substantially. As an example,
we employ a model LC wave function to calculate the pion form factor and then
compare the numerical predictions with the experimental data. It is shown that
the soft contribution is less important at the intermediate energy region.Comment: 21 pages, 4 figure
Small ball probability, Inverse theorems, and applications
Let be a real random variable with mean zero and variance one and
be a multi-set in . The random sum
where are iid copies of
is of fundamental importance in probability and its applications.
We discuss the small ball problem, the aim of which is to estimate the
maximum probability that belongs to a ball with given small radius,
following the discovery made by Littlewood-Offord and Erdos almost 70 years
ago. We will mainly focus on recent developments that characterize the
structure of those sets where the small ball probability is relatively
large. Applications of these results include full solutions or significant
progresses of many open problems in different areas.Comment: 47 page
Thermoelectric energy recovery at ionic-liquid/electrode interface
A Thermally Chargeable Capacitor containing a binary solution of
1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide (EMIMTFSI) in
acetonitrile is electrically charged by applying a tempera- ture gradient to
two ideally polarisable electrodes. The corresponding thermoelectric
coefficient is -1.7 mV/K for platinum foil electrodes and -0.3 mV/K for
nanoporous carbon electrodes. Stored electrical energy is extracted by
discharging the capacitor through a resistor. The measured capacitance of the
electrode/ionic- liquid interface is 5 micro F for each platinum electrode
while it becomes four orders of magnitude larger mF for a single
nanoporous carbon electrode. Reproducibility of the effect through repeated
charging-discharging cycles under a steady-state temperature gradient
demonstrates the robustness of the electrical charging pro- cess at the
liquid/electrode interface. The acceleration of the charging by convective
flows is also observed. This offers the possibility to convert waste-heat into
electric energy without exchanging electrons between ions and electrodes, in
contrast to what occurs in most thermogalvanic cells.Comment: 8 pages, 11 figure
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