2,186 research outputs found
The importance of check-cashing businesses to the unbanked: racial/ethnic differences
The roughly 9.5 percent of all U.S. families that are without some type of transaction account (unbanked) are disproportionately represented by minorities. The unbanked often must rely on alternative ways to carry out basic financial transactions such as cashing payroll checks and paying bills. This study analyzes unique survey data and finds that a consumer's decision to patronize check-cashing businesses is jointly made with the decision to be unbanked. For the unbanked, these businesses are an important source for financial services. Attributes that contribute to these decisions, however, vary for each racial/ethnic group. Latent preference effects are also observed to influence this joint decision for Blacks and Hispanics. These findings may explain in part why the provisions of the Debt Collection Improvement Act (DCIA) of 1996 have not been more successful in bringing unbanked federal benefits recipients into the financial mainstream. ; Consumer participation in mainstream financial markets can improve their ability to build assets and create wealth, protect them from theft and discriminatory, predatory or unsavory lending practices, and may promote economic stability and vitality in the communities where they reside. By more fully understanding a consumer's financial decisions, policies can be better directed to improve the effectiveness of legislation such as the DCIA of 1996 in encouraging mainstream financial market participation.Nonbank financial institutions ; Debt management ; Checks
The strange quark condensate in the nucleon in 2+1 flavor QCD
We calculate the "strange quark content of the nucleon", ,
which is important for interpreting the results of some dark matter detection
experiments. The method is to evaluate quark-line disconnected correlations on
the MILC lattice ensembles, which include the effects of dynamical strange
quarks. After continuum and chiral extrapolations, the result is <N |s s_bar
|N> = 0.69 +- 0.07(statistical) +- 0.09(systematic), in the modified minimal
subtraction scheme (2 GeV), or for the renormalization scheme invariant form,
m_s partial{M_N}/partial{m_s} = 59(6)(8) MeV.Comment: Added figures and references, especially for fit range choice. Other
changes for clarity. Version to appear in publicatio
Demonstration of an optical-coherence converter
Studying the coherence of an optical field is typically compartmentalized
with respect to its different optical degrees of freedom (DoFs) -- spatial,
temporal, and polarization. Although this traditional approach succeeds when
the DoFs are uncoupled, it fails at capturing key features of the field's
coherence if the DOFs are indeed correlated -- a situation that arises often.
By viewing coherence as a `resource' that can be shared among the DoFs, it
becomes possible to convert the entropy associated with the fluctuations in one
DoF to another DoF that is initially fluctuation-free. Here, we verify
experimentally that coherence can indeed be reversibly exchanged -- without
loss of energy -- between polarization and the spatial DoF of a partially
coherent field. Starting from a linearly polarized spatially incoherent field
-- one that produces no spatial interference fringes -- we obtain a spatially
coherent field that is unpolarized. By reallocating the entropy to
polarization, the field becomes invariant with regards to the action of a
polarization scrambler, thus suggesting a strategy for avoiding the deleterious
effects of a randomizing system on a DoF of the optical field.Comment: 7 pages; 6 figure
Numerical Computations in the Worldsheet Formulation
The worldsheet formulation of lattice gauge theories has two appealing
features: the gauge non-redundancy and the geometrical transparency. Both
properties are profitable in order to perform numerical computations. In the
case of dynamical fermions this description offers additional advantages. For
instance, it does not suffer from the species doubling problem and it involves
fewer degrees of freedom.Comment: Talk presented at LATTICE 97, Edinburgh. 3 pages, 2 .eps figures,
uses espcrc2.st
Chiral nature of magnetic monopoles in artificial spin ice
Micromagnetic properties of monopoles in artificial kagome spin ice systems
are investigated using numerical simulations. We show that micromagnetics
brings additional complexity into the physics of these monopoles that is, by
essence, absent in spin models: besides a fractionalized classical magnetic
charge, monopoles in the artificial kagome ice are chiral at remanence. Our
simulations predict that the chirality of these monopoles can be controlled
without altering their charge state. This chirality breaks the vertex symmetry
and triggers a directional motion of the monopole under an applied magnetic
field. Our results also show that the choice of the geometrical features of the
lattice can be used to turn on and off this chirality, thus allowing the
investigation of chiral and achiral monopoles.Comment: 10 pages, 4 figure
High density QCD with static quarks
We study lattice QCD in the limit that the quark mass and chemical potential
are simultaneously made large, resulting in a controllable density of quarks
which do not move. This is similar in spirit to the quenched approximation for
zero density QCD. In this approximation we find that the deconfinement
transition seen at zero density becomes a smooth crossover at any nonzero
density, and that at low enough temperature chiral symmetry remains broken at
all densities.Comment: LaTeX, 18 pages, uses epsf.sty, postscript figures include
A Novel Approach for Ellipsoidal Outer-Approximation of the Intersection Region of Ellipses in the Plane
In this paper, a novel technique for tight outer-approximation of the
intersection region of a finite number of ellipses in 2-dimensional (2D) space
is proposed. First, the vertices of a tight polygon that contains the convex
intersection of the ellipses are found in an efficient manner. To do so, the
intersection points of the ellipses that fall on the boundary of the
intersection region are determined, and a set of points is generated on the
elliptic arcs connecting every two neighbouring intersection points. By finding
the tangent lines to the ellipses at the extended set of points, a set of
half-planes is obtained, whose intersection forms a polygon. To find the
polygon more efficiently, the points are given an order and the intersection of
the half-planes corresponding to every two neighbouring points is calculated.
If the polygon is convex and bounded, these calculated points together with the
initially obtained intersection points will form its vertices. If the polygon
is non-convex or unbounded, we can detect this situation and then generate
additional discrete points only on the elliptical arc segment causing the
issue, and restart the algorithm to obtain a bounded and convex polygon.
Finally, the smallest area ellipse that contains the vertices of the polygon is
obtained by solving a convex optimization problem. Through numerical
experiments, it is illustrated that the proposed technique returns a tighter
outer-approximation of the intersection of multiple ellipses, compared to
conventional techniques, with only slightly higher computational cost
The intrinsic strangeness and charm of the nucleon using improved staggered fermions
We calculate the intrinsic strangeness of the nucleon, - ,
using the MILC library of improved staggered gauge configurations using the
Asqtad and HISQ actions. Additionally, we present a preliminary calculation of
the intrinsic charm of the nucleon using the HISQ action with dynamical charm.
The calculation is done with a method which incorporates features of both
commonly-used methods, the direct evaluation of the three-point function and
the application of the Feynman- Hellman theorem. We present an improvement on
this method that further reduces the statistical error, and check the result
from this hybrid method against the other two methods and find that they are
consistent. The values for and found here, together with
perturbative results for heavy quarks, show that dark matter scattering through
Higgs-like exchange receives roughly equal contributions from all heavy quark
flavors.Comment: 17 pages, 14 figure
Ear-clipping Based Algorithms of Generating High-quality Polygon Triangulation
A basic and an improved ear clipping based algorithm for triangulating simple
polygons and polygons with holes are presented. In the basic version, the ear
with smallest interior angle is always selected to be cut in order to create
fewer sliver triangles. To reduce sliver triangles in further, a bound of angle
is set to determine whether a newly formed triangle has sharp angles, and edge
swapping is accepted when the triangle is sharp. To apply the two algorithms on
polygons with holes, "Bridge" edges are created to transform a polygon with
holes to a degenerate polygon which can be triangulated by the two algorithms.
Applications show that the basic algorithm can avoid creating sliver triangles
and obtain better triangulations than the traditional ear clipping algorithm,
and the improved algorithm can in further reduce sliver triangles effectively.
Both of the algorithms run in O(n2) time and O(n) space.Comment: Proceedings of the 2012 International Conference on Information
Technology and Software Engineering Lecture Notes in Electrical Engineering
Volume 212, 2013, pp 979-98
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