11,996 research outputs found
Scale invariant correlations and the distribution of prime numbers
Negative correlations in the distribution of prime numbers are found to
display a scale invariance. This occurs in conjunction with a nonstationary
behavior. We compare the prime number series to a type of fractional Brownian
motion which incorporates both the scale invariance and the nonstationary
behavior. Interesting discrepancies remain. The scale invariance also appears
to imply the Riemann hypothesis and we study the use of the former as a test of
the latter.Comment: 13 pages, 8 figures, version to appear in J. Phys.
A comparison of cognitive restructuring and thought listing for excessive acquiring in hoarding disorder
Excessive acquiring is a common symptom of hoarding disorder (HD). Little is known about subjective distress associated with acquiring in HD. The present study examined acquiring- related distress and reactions to cognitive restructuring (CR) in 92 individuals with HD and 66 community control (CC) participants. All participants identified an item of interest at a high-risk acquiring location and then decided whether or not to acquire the item. HD participants completed the acquiring task while receiving a CR-based intervention or a thought-listing (TL) control condition. Results showed that HD participants reported more severe distress and greater urges to acquire the item of interest than did CC participants. Nevertheless, subjective distress decreased in both groups following the acquiring task. There were no differences in acquiring- related distress between the CR and TL conditions. The findings indicate that subjective distress may decrease after relatively short periods of time in individuals with HD, but that a single session of CR may not alleviate acquiring-related distress in HD participants.R01 MH068007 - NIMH NIH HHS; R01 MH068008 - NIMH NIH HHSAccepted manuscrip
Learning cover context-free grammars from structural data
We consider the problem of learning an unknown context-free grammar when the
only knowledge available and of interest to the learner is about its structural
descriptions with depth at most The goal is to learn a cover
context-free grammar (CCFG) with respect to , that is, a CFG whose
structural descriptions with depth at most agree with those of the
unknown CFG. We propose an algorithm, called , that efficiently learns
a CCFG using two types of queries: structural equivalence and structural
membership. We show that runs in time polynomial in the number of
states of a minimal deterministic finite cover tree automaton (DCTA) with
respect to . This number is often much smaller than the number of states
of a minimum deterministic finite tree automaton for the structural
descriptions of the unknown grammar
A note on the calculation of the effective range
The closed form of the first order non-linear differential equation that is
satisfied by the effective range within the variable phase formulation of
scattering theory is discussed. It is shown that the conventional method of
determining the effective range, by fitting a numerical solution of the
Schr\"odinger equation to known asymptotic boundary conditions, can be modified
to include the first order contribution of a long range interaction.Comment: 4 page
Agents Play Mix-game
In mix-game which is an extension of minority game, there are two groups of
agents; group1 plays the majority game, but the group2 plays the minority game.
This paper studies the change of the average winnings of agents and
volatilities vs. the change of mixture of agents in mix-game model. It finds
that the correlations between the average winnings of agents and the mean of
local volatilities are different with different combinations of agent memory
length when the proportion of agents in group 1 increases. This study result
suggests that memory length of agents in group1 be smaller than that of agent
in group2 when mix-game model is used to simulate the financial markets.Comment: 8 pages, 6 figures, 3 table
Bi-layer Kinetic Inductance Detectors for space observations between 80-120 GHz
We have developed Lumped Element Kinetic Inductance Detectors (LEKID)
sensitive in the frequency band from 80 to 120~GHz. In this work, we take
advantage of the so-called proximity effect to reduce the superconducting gap
of Aluminium, otherwise strongly suppressing the LEKID response for frequencies
smaller than 100~GHz. We have designed, produced and optically tested various
fully multiplexed arrays based on multi-layers combinations of Aluminium (Al)
and Titanium (Ti). Their sensitivities have been measured using a dedicated
closed-circle 100 mK dilution cryostat and a sky simulator allowing to
reproduce realistic observation conditions. The spectral response has been
characterised with a Martin-Puplett interferometer up to THz frequencies, and
with a resolution of 3~GHz. We demonstrate that Ti-Al LEKID can reach an
optical sensitivity of about ~ (best pixel), or
~ when averaged over the whole array. The optical
background was set to roughly 0.4~pW per pixel, typical for future space
observatories in this particular band. The performance is close to a
sensitivity of twice the CMB photon noise limit at 100~GHz which drove the
design of the Planck HFI instrument. This figure remains the baseline for the
next generation of millimetre-wave space satellites.Comment: 7 pages, 9 figures, submitted to A&
A Comparison of Cognitive Restructuring And Thought Listing For Excessive Acquiring In Hoarding Disorder
Excessive acquiring is a common symptom of hoarding disorder (HD). Little is known about subjective distress associated with acquiring in HD. The present study examined acquiring-related distress and reactions to cognitive restructuring (CR) in 92 individuals with HD and 66 community control (CC) participants. All participants identified an item of interest at a high-risk acquiring location and then decided whether or not to acquire the item. HD participants completed the acquiring task while receiving a CR-based intervention or a thought-listing (TL) control condition. Results showed that HD participants reported more severe distress and greater urges to acquire the item of interest than did CC participants. Nevertheless, subjective distress decreased in both groups following the acquiring task. There were no differences in acquiring-related distress between the CR and TL conditions. The findings indicate that subjective distress may decrease after relatively short periods of time in individuals with HD, but that a single session of CR may not alleviate acquiring-related distress in HD participants
Microscopic Theory of Josephson Mesoscopic Constrictions
We present a microscopic theory for the d.c. Josephson effect in model
mesoscopic constrictions. Our method is based on a non-equilibrium Green
function formalism which allows for a self-consistent determination of the
order parameter profile along the constriction. The various regimes defined by
the different length scales (Fermi wavelength , coherence length
and constriction length ) can be analyzed, including the case
where all these lengths are comparable. For the case phase oscillations with spatial period can be
observed. In the case of solutions with a phase-slip center inside
the constriction can be found, in agreement with previous phenomenological
theories.Comment: 4 pages (RevTex 3.0), 3 postscript figures available upon request,
312456-C
Nonequilibrium orbital magnetization of strongly localized electrons
The magnetic response of strongly localized electrons to a time-dependent
vector potential is considered. The orbital magnetic moment of the system, away
from steady-state conditions, is obtained. The expression involves the
tunneling and phonon-assisted hopping currents between localized states. The
frequency and temperature dependence of the orbital magnetization is analyzed
as function of the admittances connecting localized levels. It is shown that
quantum interference of the localized wave functions contributes to the moment
a term which follows adiabatically the time-dependent perturbation.Comment: RevTeX 3.
Ab Initio Calculation of Crystalline Electric Fields and Kondo Temperatures in Ce-Compounds
We have calculated the band- hybridizations for CeLaM
compounds ( and ; M=Pb, In, Sn, Pd) within the local
density approximation and fed this into a non-crossing approximation for the
Anderson impurity model applied to both dilute and concentrated limits. Our
calculations produce crystalline electric field splittings and Kondo
temperatures with trends in good agreement with experiment and demonstrate the
need for detailed electronic structure information on hybridization to describe
the diverse behaviors of these Ce compounds.Comment: 13 pages(RevTeX), 3 Postscript figure
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