12,157 research outputs found
Motion of a symmetric rigid body under the action of a body-fixed force
Approximative method for predicting motion of symmetric rigid body subjected to body-fixed forc
Differential Entropy on Statistical Spaces
We show that the previously introduced concept of distance on statistical
spaces leads to a straightforward definition of differential entropy on these
statistical spaces. These spaces are characterized by the fact that their
points can only be localized within a certain volume and exhibit thus a feature
of fuzziness. This implies that Riemann integrability of relevant integrals is
no longer secured. Some discussion on the specialization of this formalism to
quantum states concludes the paper.Comment: 4 pages, to appear in the proceedings of the joint meeting of the 2nd
International Conference on Cybernetics and Information Technologies, Systems
and Applications (CITSA 2005) and the 11th International Conference on
Information Systems Analysis and Synthesis (ISAS 2005), to be held in
Orlando, USA, on July 14-17, 200
Monitoring Costs and the Mode of International Investment
contract, vertical integration, opportunism, international investment, China
Effect of unitary impurities in non-STM-types of tunneling in high-T_c superconductors
Based on an extended Hubbard model, we present calculations of both the local
(i.e., single-site) and spatially-averaged differential tunneling conductance
in d-wave superconductors containing nonmagnetic impurities in the unitary
limit. Our results show that a random distribution of unitary impurities of any
concentration can at most give rise to a finite zero-bias conductance (with no
peak there) in spatially-averaged non-STM type of tunneling, in spite of the
fact that local tunneling in the immediate vicinity of an isolated impurity
does show a conductance peak at zero bias, whereas to give rise to even a small
zero-bias conductance peak in the former type of tunneling the impurities must
form dimers, trimers, etc. along the [110] directions. In addition, we find
that the most-recently-observed novel pattern of the tunneling conductance
around a single impurity by Pan et al. [Nature (London) 403,746 (2000)] can be
explained in terms of a realistic model of the tunneling configuration which
gives rise to the experimental results reported there. The key feature in this
model is the blocking effect of the BiO and SrO layers which exist between the
tunneling tip and the CuO_2 layer being probed.Comment: 9 pages, 7 ps-figures, to appear in Phys. Rev. B (Sep. 1, 2000);
typos corrected, references added, figure 6 changed to expand the explanation
on recent experimental measurements by S.H. Pan et al. [Nature (London) 403,
746 (2000)
Monitoring Costs and the Mode of International Investment
Our central proposition is that monitoring costs increase with physical distance, and hence, direct investments located further from the foreign investor’s home base should be more likely formed as joint ventures. Tests on a data set of Taiwanese direct investments in Mainland China provide robust support to the hypothesis. A project that was located 1000 kilometers further away was 13-17% more likely to be formed as a joint venture.contract, vertical integration, opportunism, international investment, China
Thermal and nonthermal dust sputtering in hydrodynamical simulations of the multiphase interstellar medium
We study the destruction of interstellar dust via sputtering in supernova
(SN) shocks using three-dimensional hydrodynamical simulations. With a novel
numerical framework, we follow both sputtering and dust dynamics governed by
direct collisions, plasma drag and betatron acceleration. Grain-grain
collisions are not included and the grain-size distribution is assumed to be
fixed. The amount of dust destroyed per SN is quantified for a broad range of
ambient densities and fitting formulae are provided. Integrated over the
grain-size distribution, nonthermal (inertial) sputtering dominates over
thermal sputtering for typical ambient densities. We present the first
simulations that explicitly follow dust sputtering within a turbulent
multiphase interstellar medium. We find that the dust destruction timescales
are 0.35 Gyr for silicate dust and 0.44 Gyr for carbon dust in solar
neighborhood conditions. The SN environment has an important impact on .
SNe that occur in preexisting bubbles destroy less dust as the destruction is
limited by the amount of dust in the shocked gas. This makes about 2.5
times longer than the estimate based on results from a single SN explosion. We
investigate the evolution of the dust-to-gas mass ratio (DGR), and find that a
spatial inhomogeneity of 14\% develops for scales below 10 pc. It
locally correlates positively with gas density but negatively with gas
temperature even in the exterior of the bubbles due to incomplete gas mixing.
This leads to a 30\% lower DGR in the volume filling warm gas compared
to that in the dense clouds.Comment: 20 pages, 16 figures, accepted versio
Quantum annealing for systems of polynomial equations
Numerous scientific and engineering applications require numerically solving
systems of equations. Classically solving a general set of polynomial equations
requires iterative solvers, while linear equations may be solved either by
direct matrix inversion or iteratively with judicious preconditioning. However,
the convergence of iterative algorithms is highly variable and depends, in
part, on the condition number. We present a direct method for solving general
systems of polynomial equations based on quantum annealing, and we validate
this method using a system of second-order polynomial equations solved on a
commercially available quantum annealer. We then demonstrate applications for
linear regression, and discuss in more detail the scaling behavior for general
systems of linear equations with respect to problem size, condition number, and
search precision. Finally, we define an iterative annealing process and
demonstrate its efficacy in solving a linear system to a tolerance of
.Comment: 11 pages, 4 figures. Added example for a system of quadratic
equations. Supporting code is available at
https://github.com/cchang5/quantum_poly_solver . This is a post-peer-review,
pre-copyedit version of an article published in Scientific Reports. The final
authenticated version is available online at:
https://www.nature.com/articles/s41598-019-46729-
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