12,842 research outputs found
Joint min-max distribution and Edwards-Anderson's order parameter of the circular -noise model
We calculate the joint min--max distribution and the Edwards-Anderson's order
parameter for the circular model of -noise. Both quantities, as well as
generalisations, are obtained exactly by combining the freezing-duality
conjecture and Jack-polynomial techniques. Numerical checks come with
significantly improved control of finite-size effects in the glassy phase, and
the results convincingly validate the freezing-duality conjecture. Application
to diffusive dynamics is discussed. We also provide a formula for the
pre-factor ratio of the joint/marginal Carpentier-Le Doussal tail for
minimum/maximum which applies to any logarithmic random energy model.Comment: 6 pages, 3 figure
Regression with respect to sensing actions and partial states
In this paper, we present a state-based regression function for planning
domains where an agent does not have complete information and may have sensing
actions. We consider binary domains and employ the 0-approximation [Son & Baral
2001] to define the regression function. In binary domains, the use of
0-approximation means using 3-valued states. Although planning using this
approach is incomplete with respect to the full semantics, we adopt it to have
a lower complexity. We prove the soundness and completeness of our regression
formulation with respect to the definition of progression. More specifically,
we show that (i) a plan obtained through regression for a planning problem is
indeed a progression solution of that planning problem, and that (ii) for each
plan found through progression, using regression one obtains that plan or an
equivalent one. We then develop a conditional planner that utilizes our
regression function. We prove the soundness and completeness of our planning
algorithm and present experimental results with respect to several well known
planning problems in the literature.Comment: 38 page
Log-correlated Random Energy Models with extensive free energy fluctuations: pathologies caused by rare events as signatures of phase transitions
We address systematically an apparent non-physical behavior of the free
energy moment generating function for several instances of the logarithmically
correlated models: the Fractional Brownian Motion with Hurst index
(fBm0) (and its bridge version), a 1D model appearing in decaying Burgers
turbulence with log-correlated initial conditions, and finally, the
two-dimensional logREM introduced in [Cao et al., Phys.Rev.Lett.,118,090601]
based on the 2D Gaussian free field (GFF) with background charges and directly
related to the Liouville field theory. All these models share anomalously large
fluctuations of the associated free energy, with a variance proportional to the
log of the system size. We argue that a seemingly non-physical vanishing of the
moment generating function for some values of parameters is related to the
termination point transition (a.k.a pre-freezing). We study the associated
universal log corrections in the frozen phase, both for log-REMs and for the
standard REM, filling a gap in the literature. For the above mentioned
integrable instances of logREMs, we predict the non-trivial free energy
cumulants describing non-Gaussian fluctuations on the top of the Gaussian with
extensive variance. Some of the predictions are tested numerically.Comment: 17 pages, 4 figure
Determinants of Capital Structure: Evidence from China Public Listed Industrial Companies
This paper examines determinants of capital structure of China-Listed companies in Shang Hai Stock Exchange. Profitability, size, growth rate and liquidity are the
variables used as the independent variables, while capital structure is proxied by leverage.The capital market of China went through a remarkable growth from 2006 to 2008, but currently it is in deep recession. This study looks at the factors that influence China's industrial companies' capital structure in a ten-year period, from 1998 to 2010. The findings show that size is positively and significantly correlated to leverage, whilst liquidity is negatively but significantly influences leverage. Both profitability and growth rates do not have any effect on capital structure of the 967 industrial companies examined. The findings also demonstrate that neither the pecking order theory nor trade-off theory derived from the western setting could
provide convincing explanation for the capital structure
choices of the China's companies. The differences in the choices may be attributed to the fundamental institutional assumptions in the western models that are not valid in China
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