3,388 research outputs found
Land-use change simulation and assessment of driving factors in the loess hilly region - a case study as Pengyang County
The main objective of this study is to evaluate the land-use change and its relationship with its driving factors in the loess hilly region. In this study, a case study was carried out in Pengyang County. We set two land-use demand scenarios (a baseline scenario (scenario 1) and a real land-use requirement scenario (scenario 2)) during year 2001-2005 via assuming the effect of driving factors on land-use change keeps stable from 1993 to 2005. Two simulated land-use patterns of 2005 are therefore achieved accordingly by use of the conversion of land use and its effects model at small regional extent. Kappa analyses are conducted to compare each simulated land-use pattern with the reality. Results show that (1) the associated kappa values were decreased from 0.83 in 1993-2000 to 0.27 (in scenario 1) and 0.23 (in scenario 2) in 2001-2005 and (2) forest and grassland were the land-use types with highest commission errors, which implies that conversion of both the land-use types mentioned above is the main determinant of change of kappa values. Our study indicates the land-use change was driven by the synthetic multiply factors including natural and social-economic factors (e.g., slope, aspect, elevation, distance to road, soil types, and population dense) in 1993-2000 until "Grain for Green Project" was implemented and has become the dominant factor in 2001-2005
Flavor Symmetry for Quarks and Leptons
Present data on neutrino masses and mixing favor the highly symmetric
tribimaximal neutrino mixing matrix which suggests an underlying flavor
symmetry. A systematic study of non-abelian finite groups of order
reveals that tribimaximal mixing can be derived not only from the well known
tetrahedral flavor symmetry , but also by using the binary
tetrahedral symmetry which does not contain the
tetrahedral group as a subgroup. has the further advantage that it can
also neatly accommodate the quark masses including a heavy top quark.Comment: 12 pages latex. More typos correcte
Non-vanishing boundary effects and quasi-first order phase transitions in high dimensional Ising models
In order to gain a better understanding of the Ising model in higher
dimensions we have made a comparative study of how the boundary, open versus
cyclic, of a d-dimensional simple lattice, for d=1,...,5, affects the behaviour
of the specific heat C and its microcanonical relative, the entropy derivative
-dS/dU. In dimensions 4 and 5 the boundary has a strong effect on the critical
region of the model and for cyclic boundaries in dimension 5 we find that the
model displays a quasi first order phase transition with a bimodal energy
distribution. The latent heat decreases with increasing systems size but for
all system sizes used in earlier papers the effect is clearly visible once a
wide enough range of values for K is considered. Relations to recent rigorous
results for high dimensional percolation and previous debates on simulation of
Ising models and gauge fields are discussed.Comment: 12 pages, 27 figure
Transonic Shocks In Multidimensional Divergent Nozzles
We establish existence, uniqueness and stability of transonic shocks for
steady compressible non-isentropic potential flow system in a multidimensional
divergent nozzle with an arbitrary smooth cross-section, for a prescribed exit
pressure. The proof is based on solving a free boundary problem for a system of
partial differential equations consisting of an elliptic equation and a
transport equation. In the process, we obtain unique solvability for a class of
transport equations with velocity fields of weak regularity(non-Lipschitz), an
infinite dimensional weak implicit mapping theorem which does not require
continuous Frechet differentiability, and regularity theory for a class of
elliptic partial differential equations with discontinuous oblique boundary
conditions.Comment: 54 page
Electromagnetic proton form factors in large QCD
The electromagnetic form factors of the proton are obtained using a
particular realization of QCD in the large limit (),
which sums up the infinite number of zero-width resonances to yield an Euler's
Beta function (Dual-). The form factors and
, as well as agree very well with reanalyzed space-like
data in the whole range of momentum transfer. In addition, the predicted ratio
is in good agreement with recent polarization transfer
measurements at Jefferson Lab.Comment: 10 page
Factors Influencing Resection in Locoregional Pancreatic Cancer Patients
Objective:
Identify factors associated with resection in a national sample of locoregional pancreatic cancer patients.
Poster presented at ISPOR conference in Washington DC.https://jdc.jefferson.edu/jcphposters/1008/thumbnail.jp
Fast Zonal Field Dynamo in Collisionless Kinetic Alfven Wave Turbulence
The possibility of fast dynamo action by collisionless kinetic Alfven Wave
turbulence is demonstrated. The irreversibility necessary to lock in the
generated field is provided by electron Landau damping, so the induced electric
field does not vanish with resistivity. Mechanisms for self-regulation of the
system and the relation of these results to the theory of alpha quenching are
discussed. The dynamo-generated fields have symmetry like to that of zonal
flows, and thus are termed zonal fields
On the effects of (partial) quenching on penguin contributions to K-> pi pi
Recently, we pointed out that chiral transformation properties of strong
penguin operators change in the transition from unquenched to (partially)
quenched QCD. As a consequence, new penguin-like operators appear in the
(partially) quenched theory, along with new low-energy constants, which should
be interpreted as a quenching artifact. Here, we extend the analysis to the
contribution of the new low-energy constants to the K^0 -> pi^+ pi^- amplitude,
at leading order in chiral perturbation theory, and for arbitrary (momentum
non-conserving) kinematics. Using these results, we provide a detailed
discussion of the intrinsic systematic error due to this (partial) quenching
artifact. We also give a simple recipe for the determination of the
leading-order low-energy constant parameterizing the new operators in the case
of strong penguins.Comment: 17 pages, 1 figure, minor correction
Compactness and existence results in weighted Sobolev spaces of radial functions. Part II: Existence
We prove existence and multiplicity results for finite energy solutions to
the nonlinear elliptic equation where is a radial domain (bounded or
unbounded) and satisfies on if and as
if is unbounded. The potential may be vanishing or unbounded at
zero or at infinity and the nonlinearity may be superlinear or sublinear.
If is sublinear, the case with is also considered.Comment: 29 pages, 8 figure
Literature Review on Hospital Costs for Patients Undergoing Colectomy
Objective:
This study aims to identify the range of direct hospital costs associated with a minimally invasive or open colectomy procedure across different countries.
Poster presented at 2016 ISPOR conference in Washington DC.https://jdc.jefferson.edu/jcphposters/1009/thumbnail.jp
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