9,001 research outputs found
Correlates of Compulsive Buying
Compulsive buying is a chronic issue for shoppers exacerbated by a nation obsessed with consumption. To predict compulsive buying behavior, a survey was administered to 283 college students in southern Nevada. The results suggested that the compulsive buyer exhibits am external consumer locus of control and purchases goods with the intent to increase social status or quell anxiety. Given that responsible financial behavior changes as a function of age, college students are particularly vulnerable to compulsive purchasing behavior, as it is exacerbated by irresponsible credit spending behaviors
Predictive context biases perceptual selection during binocular rivalry
Prediction may be a fundamental principle of sensory processing, such that the brain continuously generates predictions about forthcoming sensory information. However, little is known about how prediction contributes to the selection of a conscious percept from among competing alternatives. Here, we used binocular rivalry to investigate the effects of prediction on perceptual selection. In binocular rivalry, incompatible images presented to the two eyes result in a perceptual alternation between the images, even though the visual stimuli remain constant. If predictive signals influence the competition between neural representations of rivalrous images, this influence should generate a bias in perceptual selection that depends on predictive context. To manipulate predictive context, we developed a novel binocular rivalry paradigm in which orthogonal rivalrous test gratings were immediately preceded by rotating gratings presented identically to the two eyes. One of the rivalrous gratings had an orientation that was consistent with the preceding rotation direction (it was the expected next image in the series), and the other had an inconsistent orientation. We found that human observers were more likely to perceive the consistent grating, suggesting that predictive context biased selection in favor of the predicted percept. This prediction effect depended on only recent stimulus history, and it could be dissociated from another stimulus history effect related to orientation-specific adaptation. Since binocular rivalry between orthogonal gratings is thought to be resolved at an early stage of visual processing, these results suggest that predictive signals may exist at low levels of the visual processing hierarchy and that these signals can bias conscious perception. In the future, this paradigm could be used to test whether visual percepts are generated from the combination of prior information and incoming sensory information according to Bayesian principles
Spin correlation functions in random-exchange s=1/2 XXZ chains
The decay of (disorder-averaged) static spin correlation functions at T=0 for
the one-dimensional spin-1/2 XXZ antiferromagnet with uniform longitudinal
coupling and random transverse coupling is investigated
by numerical calculations for ensembles of finite chains. At (XX
model) the calculation is based on the Jordan-Wigner mapping to free lattice
fermions for chains with up to N=100 sites. At Lanczos
diagonalizations are carried out for chains with up to N=22 sites. The
longitudinal correlation function is found to exhibit a
power-law decay with an exponent that varies with $\Delta$ and, for nonzero
$\Delta$, also with the width of the $\lambda_i$-distribution. The results for
the transverse correlation function show a crossover from
power-law decay to exponential decay as the exchange disorder is turned on.Comment: RevTex manuscript (7 pages), 4 postscript figure
A Methodology for the Range Ordering of Alternatives using a Bayesian Decision Model with Applications to the Space Program
The primary objective of this paper is to provide a reasonably general and essentially unified approach to those problems involving value judgments and subjective decision making, without regard to excessive rigor. The principle areas and methods of attack developed are:
(1) The selection of a value measure which emphasizes the fact that the criterion of optimum performance is quite arbitrary, its merits reflecting only the constraints on the problem and the objectives sought,
(2) The utilization of statistical decision theory as a basis for the solution and subsequent ev aluation of a class of problems in which a priori value judgments must be assigned by an individual or committee under uncertainty, and
(3) The application of the methodology to those areas in which the relative uncertainty level of a decision need be assessed in terms of a cost or penalty incurred in reaching the conclusion. A parti cularly important application is the selection of alternatives (ioe., projects by corporate executives) and the subsequent sensitivity analysis of the decision
Control of the finite size corrections in exact diagonalization studies
We study the possibility of controlling the finite size corrections in exact
diagonalization studies quantitatively. We consider the one- and two
dimensional Hubbard model. We show that the finite-size corrections can be be
reduced systematically by a grand-canonical integration over boundary
conditions. We find, in general, an improvement of one order of magnitude with
respect to studies with periodic boundary conditions only. We present results
for ground-state properties of the 2D Hubbard model and an evaluation of the
specific heat for the 1D and 2D Hubbard model.Comment: Phys. Rev. B (Brief Report), in pres
A Monte Carlo Method for Fermion Systems Coupled with Classical Degrees of Freedom
A new Monte Carlo method is proposed for fermion systems interacting with
classical degrees of freedom. To obtain a weight for each Monte Carlo sample
with a fixed configuration of classical variables, the moment expansion of the
density of states by Chebyshev polynomials is applied instead of the direct
diagonalization of the fermion Hamiltonian. This reduces a cpu time to scale as
compared to for the
diagonalization in the conventional technique; is the dimension
of the Hamiltonian. Another advantage of this method is that parallel
computation with high efficiency is possible. These significantly save total
cpu times of Monte Carlo calculations because the calculation of a Monte Carlo
weight is the bottleneck part. The method is applied to the double-exchange
model as an example. The benchmark results show that it is possible to make a
systematic investigation using a system-size scaling even in three dimensions
within a realistic cpu timescale.Comment: 6 pages including 4 figure
A number or a person?: perspectives on credit scoring and fair mortgage lending: article four in a five-part series
This fourth article in a five-part series on credit scoring showcases three different perspectives. Up for debate is how lenders can ensure fair treatment to all mortgage applicants and how consumers can be educated about the effect their credit score has on loan pricing.Mortgage loans
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