2,134 research outputs found
Strong Approximation of Empirical Copula Processes by Gaussian Processes
We provide the strong approximation of empirical copula processes by a
Gaussian process. In addition we establish a strong approximation of the
smoothed empirical copula processes and a law of iterated logarithm
Consistent thermodynamics for spin echoes
Spin-echo experiments are often said to constitute an instant of
anti-thermodynamic behavior in a concrete physical system that violates the
second law of thermodynamics. We argue that a proper thermodynamic treatment of
the effect should take into account the correlations between the spin and
translational degrees of freedom of the molecules. To this end, we construct an
entropy functional using Boltzmann macrostates that incorporates both spin and
translational degrees of freedom. With this definition there is nothing special
in the thermodynamics of spin echoes: dephasing corresponds to Hamiltonian
evolution and leaves the entropy unchanged; dissipation increases the entropy.
In particular, there is no phase of entropy decrease in the echo. We also
discuss the definition of macrostates from the underlying quantum theory and we
show that the decay of net magnetization provides a faithful measure of entropy
change.Comment: 15 pages, 2 figs. Changed figures, version to appear in PR
An Alternative Interpretation of Statistical Mechanics
In this paper I propose an interpretation of classical statistical mechanics that centers on taking seriously the idea that probability measures represent complete states of statistical mechanical systems. I show how this leads naturally to the idea that the stochasticity of statistical mechanics is associated directly with the observables of the theory rather than with the microstates (as traditional accounts would have it). The usual assumption that microstates are representationally significant in the theory is therefore dispensable, a consequence which suggests interesting possibilities for developing non-equilibrium statistical mechanics and investigating inter-theoretic answers to the foundational questions of statistical mechanics
Design of coupling for synchronization in time-delayed systems
We report a design of delay coupling for targeting desired synchronization in
delay dynamical systems. We target synchronization, antisynchronization, lag-,
antilag- synchronization, amplitude death (or oscillation death) and
generalized synchronization in mismatched oscillators. A scaling of the size of
an attractor is made possible in different synchronization regimes. We realize
a type of mixed synchronization where synchronization, antisynchronization
coexist in different pairs of state variables of the coupled system. We
establish the stability condition of synchronization using the
Krasovskii-Lyapunov function theory and the Hurwitz matrix criterion. We
present numerical examples using the Mackey-Glass system and a delay
R\"{o}ssler system.Comment: 8 pages, 6 figures; Chaos 22 (2012
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Estimating the Binary Endogenous Effect of Insurance on Doctor Visits by Copula-Based Regression Additive Models
This paper seeks to estimate the causal effect of having health insurance on health care utilization, while accounting for potential endogeneity bias. The topic has impor- tant policy implications, because health insurance reforms implemented in U.S. in recent decades have focused on extending coverage to the previously uninsured. Consequently, understanding the effects of those reforms requires an accurate estimate of the causal effect of insurance on utilization. However, obtaining such an estimate is complicated by the discreteness inherent in common measures of health care usage. This paper presents a flexible estimation approach, based on copula functions, that consistently estimates the coefficient of a binary endogenous regressor in count data settings. The relevant numeri- cal computations can be easily carried out using the freely available GJRM R package. The empirical results find significant evidence of favorable selection into insurance. Ignoring such selection, insurance appears to increase doctor visit usage by 62%, but adjusting for it, the effect increases to 134%
Functional Analysis of the TAN-1 Gene, a Human Homolog of Drosophila Notch
The TAN-1 gene was originally discovered at the breakpoint of a recurrent (7;9)(q34;q34.3) chromosomal translocation found in a subset of human T-lymphoblastic leukemias (Reynolds et al. 1987; Smith et al. 1988; Ellisen et al. 1991). This translocation joins roughly the 3′ half of TAN-1 head-to-head with the 3′ portion of the β T-cell-receptor gene (TCRB) beginning at the 5′ boundary of one or the other J segment. Intact TAN-1 is normally transcribed into an 8.2-kb transcript that is present in many tissues, most abundantly in developing thymus and spleen (Ellisen et al. 1991). This tissue distribution and the apparent involvement of an altered version of the gene in T-cell cancers have suggested that TAN-1 normally has some special function in lymphocytes or their precursors
The arrow of time: from universe time-asymmetry to local irreversible processes
In several previous papers we have argued for a global and non-entropic
approach to the problem of the arrow of time, according to which the ''arrow''
is only a metaphorical way of expressing the geometrical time-asymmetry of the
universe. We have also shown that, under definite conditions, this global
time-asymmetry can be transferred to local contexts as an energy flow that
points to the same temporal direction all over the spacetime. The aim of this
paper is to complete the global and non-entropic program by showing that our
approach is able to account for irreversible local phenomena, which have been
traditionally considered as the physical origin of the arrow of time.Comment: 48 pages, 8 figures, revtex4. Accepted for publication in Foundations
of Physic
Background-Independence
Intuitively speaking, a classical field theory is background-independent if
the structure required to make sense of its equations is itself subject to
dynamical evolution, rather than being imposed ab initio. The aim of this paper
is to provide an explication of this intuitive notion. Background-independence
is not a not formal property of theories: the question whether a theory is
background-independent depends upon how the theory is interpreted. Under the
approach proposed here, a theory is fully background-independent relative to an
interpretation if each physical possibility corresponds to a distinct spacetime
geometry; and it falls short of full background-independence to the extent that
this condition fails.Comment: Forthcoming in General Relativity and Gravitatio
Analysis of BENCHMRK 1 & 2 using PhenoSense® assay for darunavir (DRV/r) resistance and exploration of functional monotherapy with RAL vs DRV
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