132,430 research outputs found
Macroscopical Entangled Coherent State Generator in V configuration atom system
In this paper, we propose a scheme to produce pure and macroscopical
entangled coherent state. When a three-level ''V'' configuration atom interacts
with a doubly reasonant cavity, under the strong classical driven condition,
entangled coherent state can be generated from vacuum fields. An analytical
solution for this system under the presence of cavity losses is also given
Conditions for Nondistortion Interrogation of Quantum System
Under some physical considerations, we present a universal formulation to
study the possibility of localizing a quantum object in a given region without
disturbing its unknown internal state. When the interaction between the object
and probe wave function takes place only once, we prove the necessary and
sufficient condition that the object's presence can be detected in an initial
state preserving way. Meanwhile, a conditioned optimal interrogation
probability is obtained.Comment: 5 pages, Revtex, 1 figures, Presentation improved, corollary 1 added.
To appear in Europhysics Letter
A highly inclined orbit for the 110-day period M-dwarf companion KOI-368.01
We report the detection of asymmetry in the transit light curves of the
110-day period companion to KOI-368, a rapidly rotating A-dwarf. The
significant distortion in the transit light curve is attributed to spin-orbit
misalignment between the transiting companion and the gravity darkened host
star. Our analysis was based on 11 Long Cadence and 2 Short Cadence transits of
KOI-368.01 from the Kepler mission, as well as stellar parameters determined
from our follow-up spectroscopic observation. We measured the true obliquity
between the orbit normal and the stellar rotation axis to be 69 +9/-10 deg. We
also find a secondary eclipse event with depth 29 +/- 3 ppm at phase 0.59, from
which the temperature of the companion is constrained to 3060 +/- 50 K,
indicating that KOI-368.01 is a late M-dwarf. The eccentricity is also
calculated from the eclipse to be 0.1429 +/- 0.0007. The long period, high
obliquity, and low eccentricity of KOI-368.01 allow us to limit a number of
proposed theories for the misalignment of binary systems.Comment: 7 pages, 4 figures, 1 table, accepted for publication in ApJ
On utilization of elliptical rings in assessing cracking tendency of concrete
A new experimental method by utilizing elliptical rings to replace circular rings recommended by ASTM and AASHTO was explored for assessing cracking potential of concrete and other cement-based materials under restrained condition. A series of thin and thick elliptical concrete rings were tested alongside circular ones until cracking. Cracking age, position, and propagation were carefully examined. It is found that thin elliptical rings with appropriate geometry can initiate cracks quicker than circular ones, which is desirable for accelerating the ring test. However, thick elliptical rings seem not to exhibit a desirable geometry effect of accelerating ring test compared with circular ones. There were multiple visible cracks that occurred in an elliptical ring and some cracks were initiated but did not propagate through the ring wall. In comparison, there was only one crack in the circular rings. Finally, the features of multiple cracks in restrained elliptical rings were examined and their impact on interpreting elliptical ring test results was elaborated. © 2014 4th International Conference on the Durability of Concrete Structures
Robust H∞ filtering for time-delay systems with probabilistic sensor faults
Copyright [2009] IEEE. This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.In this paper, a new robust H∞ filtering problem is investigated for a class of time-varying nonlinear system with norm-bounded parameter uncertainties, bounded state delay, sector-bounded nonlinearity and probabilistic sensor gain faults. The probabilistic sensor reductions are modeled by using a random variable that obeys a specific distribution in a known interval [alpha,beta], which accounts for the following two phenomenon: 1) signal stochastic attenuation in unreliable analog channel and 2) random sensor gain reduction in severe environment. The main task is to design a robust H∞ filter such that, for all possible uncertain measurements, system parameter uncertainties, nonlinearity as well as time-varying delays, the filtering error dynamics is asymptotically mean-square stable with a prescribed H∞ performance level. A sufficient condition for the existence of such a filter is presented in terms of the feasibility of a certain linear matrix inequality (LMI). A numerical example is introduced to illustrate the effectiveness and applicability of the proposed methodology
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