15,797 research outputs found
Information Landscape and Flux, Mutual Information Rate Decomposition and Entropy Production
We explore the dynamics of information systems. We show that the driving
force for information dynamics is determined by both the information landscape
and information flux which determines the equilibrium time reversible and the
nonequilibrium time-irreversible behaviours of the system respectively. We
further demonstrate that the mutual information rate between the two subsystems
can be decomposed into the time-reversible and time-irreversible parts
respectively, analogous to the information landscape-flux decomposition for
dynamics. Finally, we uncover the intimate relation between the nonequilibrium
thermodynamics in terms of the entropy production rates and the
time-irreversible part of the mutual information rate. We demonstrate the above
features by the dynamics of a bivariate Markov chain.Comment: 16 page
Cost-aware Defense for Parallel Server Systems against Reliability and Security Failures
Parallel server systems in transportation, manufacturing, and computing
heavily rely on dynamic routing using connected cyber components for
computation and communication. Yet, these components remain vulnerable to
random malfunctions and malicious attacks, motivating the need for
fault-tolerant dynamic routing that are both traffic-stabilizing and
cost-efficient. In this paper, we consider a parallel server system with
dynamic routing subject to reliability and stability failures. For the
reliability setting, we consider an infinite-horizon Markov decision process
where the system operator strategically activates protection mechanism upon
each job arrival based on traffic state observations. We prove an optimal
deterministic threshold protecting policy exists based on dynamic programming
recursion of the HJB equation. For the security setting, we extend the model to
an infinite-horizon stochastic game where the attacker strategically
manipulates routing assignment. We show that both players follow a threshold
strategy at every Markov perfect equilibrium. For both failure settings, we
also analyze the stability of the traffic queues under control. Finally, we
develop approximate dynamic programming algorithms to compute the
optimal/equilibrium policies, supplemented with numerical examples and
experiments for validation and illustration.Comment: Major Revision in Automatic
Exothermic isospin-violating dark matter after SuperCDMS and CDEX
We show that exothermic isospin-violating dark matter (IVDM) can make the
results of the latest CDMS-Si experiment consistent with recent null
experiments, such as XENON10, XENON100, LUX, CDEX, and SuperCDMS, whereas for
the CoGeNT experiment, a strong tension still persists. For CDMS-Si, separate
exothermic dark matter or isospin-violating dark matter cannot fully ameliorate
the tensions among these experiments; the tension disappears only if exothermic
scattering is combined with an isospin-violating effect of f_n/f_p=-0.7. For
such exothermic IVDM to exist, at least a new vector gauge boson (dark photon
or dark Z') that connects SM quarks to Majorana-type DM particles is required.Comment: 12 pages, 6 figure
Transmission resonance in a composite plasmonic structure
The design, fabrication, and optical properties of a composite plasmonic
structure, a two-dimentional array of split-ring resonators inserted into
periodic square holes of a metal film, have been reported. A new type of
transmission resonance, which makes a significant difference from the
conventional peaks, has been suggested both theoretically and experimentally.
To understand this effect, a mechanism of ring- resonance induced dipole
emission is proposed.Comment: 14 pages, 4 figure
Numerical methods for contact between two joined quarter spaces and a rigid sphere
AbstractQuarter space problems have many useful applications wherever an edge is involved, and solution to the related contact problem requires extension to the classical Hertz theory. However, theoretical exploration of such a problem is limited, due to the complexity of the involved boundary conditions. The present study proposes a novel numerical approach to compute the elastic field of two quarter spaces, joined so that their top surfaces occupy the same plane, and indented by a rigid sphere with friction. In view of the equivalent inclusion method, the joined quarter spaces may be converted to a homogeneous half space with properly established eigenstrains, which are analyzed by our recent half space-inclusion solution using a three-dimensional fast Fourier transform algorithm. Benchmarked with finite element analysis the present method of solution demonstrates both accuracy and efficiency. A number of interesting parametric studies are also provided to illustrate the effects of material combinations, contact location and friction coefficient showing the deviation of the solution from Hertz theory
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