2,210 research outputs found
Dimensionality Reduction in Deep Learning for Chest X-Ray Analysis of Lung Cancer
Efficiency of some dimensionality reduction techniques, like lung
segmentation, bone shadow exclusion, and t-distributed stochastic neighbor
embedding (t-SNE) for exclusion of outliers, is estimated for analysis of chest
X-ray (CXR) 2D images by deep learning approach to help radiologists identify
marks of lung cancer in CXR. Training and validation of the simple
convolutional neural network (CNN) was performed on the open JSRT dataset
(dataset #01), the JSRT after bone shadow exclusion - BSE-JSRT (dataset #02),
JSRT after lung segmentation (dataset #03), BSE-JSRT after lung segmentation
(dataset #04), and segmented BSE-JSRT after exclusion of outliers by t-SNE
method (dataset #05). The results demonstrate that the pre-processed dataset
obtained after lung segmentation, bone shadow exclusion, and filtering out the
outliers by t-SNE (dataset #05) demonstrates the highest training rate and best
accuracy in comparison to the other pre-processed datasets.Comment: 6 pages, 14 figure
Off-Diagonal Long-Range Order: Meissner Effect and Flux Quantization
There has been a proof by Sewell that the hypothesis of off-diagonal
long-range order in the reduced density matrix implies the Meissner
effect. We present in this note an elementary and straightforward proof that
not only the Meissner effect but also the property of magnetic flux
quantization follows from the hypothesis. It is explicitly shown that the two
phenomena are closely related, and phase coherence is the origin for both.Comment: 11 pages, Latex fil
Extended dual description of Mott transition beyond two-dimensional space
Motivated by recent work of Mross and Senthil [Phys. Rev. B \textbf{84},
165126 (2011)] which provides a dual description for Mott transition from Fermi
liquid to quantum spin liquid in two space dimensions, we extend their approach
to higher dimensional cases, and we provide explicit formalism in three space
dimensions. Instead of the vortices driving conventional Fermi liquid into
quantum spin liquid states in 2D, it is the vortex lines to lead to the
instability of Fermi liquid in 3D. The extended formalism can result in rich
consequences when the vortex lines condense in different degrees of freedom.
For example, when the vortex lines condense in charge phase degrees of freedom,
the resulting effective fermionic action is found to be equivalent to that
obtained by well-studied slave-particle approaches for Hubbard and/or Anderson
lattice models, which confirm the validity of the extended dual formalism in
3D. When the vortex lines condense in spin phase degrees of freedom, a doublon
metal with a spin gap and an instability to the unconventional superconducting
pairing can be obtained. In addition, when the vortex lines condense in both
phase degrees, an exotic doubled U(1) gauge theory occurs which describes a
separation of spin-opposite fermionic excitations. It is noted that the first
two features have been discussed in a similar way in 2D, the last one has not
been reported in the previous works. The present work is expected to be useful
in understanding the Mott transition happening beyond two space dimensions.Comment: 7 pages, no figure
Integrating static and dynamic information for routing traffic
The efficiency of traffic routing on complex networks can be reflected by two
key measurements i.e. the system capacity and the average data packets travel
time. In this paper, we propose a mixing routing strategy by integrating local
static and dynamic information for enhancing the efficiency of traffic on
scale-free networks. The strategy is governed by a single parameter. Simulation
results show that there exists a optimal parameter value by considering both
maximizing the network capacity and reducing the packet travel time. Comparing
with the strategy by adopting exclusive local static information, the new
strategy shows its advantages in improving the efficiency of the system. The
detailed analysis of the mixing strategy is provided. This work suggests that
how to effectively utilize the larger degree nodes plays the key role in the
scale-free traffic systems.Comment: 5 pages, 5 figure
Effective-mass Klein-Gordon Equation for non-PT/non-Hermitian Generalized Morse Potential
The one-dimensional effective-mass Klein-Gordon equation for the real, and
non-\textrm{PT}-symmetric/non-Hermitian generalized Morse potential is solved
by taking a series expansion for the wave function. The energy eigenvalues, and
the corresponding eigenfunctions are obtained. They are also calculated for the
constant mass case.Comment: 14 page
Magnetic Properties of J-J-J' Quantum Heisenberg Chains with Spin S=1/2, 1, 3/2 and 2 in a Magnetic Field
By means of the density matrix renormalization group (DMRG) method, the
magnetic properties of the J-J-J quantum Heisenberg chains with spin
, 1, 3/2 and 2 in the ground states are investigated in the presence of
a magnetic field. Two different cases are considered: (a) when is
antiferromagnetic and is ferromagnetic (i.e. the AF-AF-F chain),
the system is a ferrimagnet. The plateaus of the magnetization are observed. It
is found that the width of the plateaus decreases with increasing the
ferromagnetic coupling, and disappears when passes over a
critical value. The saturated field is observed to be independent of the
ferromagnetic coupling; (b) when is ferromagnetic and is
antiferromagnetic (i.e. the F-F-AF chain), the system becomes an
antiferromagnet. The plateaus of the magnetization are also seen. The width of
the plateaus decreases with decreasing the antiferromagnetic coupling, and
disappears when passes over a critical value. Though the ground
state properties are quite different, the magnetization plateaus in both cases
tend to disappear when the ferromagnetic coupling becomes more dominant.
Besides, no fundamental difference between the systems with spin half-integer
and integer has been found.Comment: 8 pages, 9 figures, to be published in J. Phys.: Condens. Matte
Index for Three Dimensional Superconformal Field Theories and Its Applications
We review aspects of superconformal indices in three dimension. Three
dimensional superconformal indices can be exactly computed by using
localization method including monopole contribution, and can be applied to
provide evidences for mirror duality, AdS_4/CFT_3 correspondence and global
symmetry enhancement of strongly coupled gauge theories. After reviewing, we
discuss the possibility of global symmetry enhancement in a finite rank of
gauge group.Comment: 14 pages, Proceedings of the Seventh International Conference Quantum
Theory and Symmetries (QTS-7) in Prague, Czech Republic, August, 2011; v2:
minor modifications, discussion of supersymmetry enhancement of abelian ABJM
theory by using an index were adde
A statistical method for adjusting covariates in linkage analysis with sib pairs
BACKGROUND: We propose a statistical method that includes the use of longitudinal regression models and estimation procedures for adjusting for covariate effects in applying the Haseman-Elston (HE) method for linkage analysis. Our methodology, which uses the covariate adjusted trait, contains three steps: a) modelling the covariate-adjusted population means of quantitative traits through regression; b) estimating the value of covariate-adjusted quantitative traits; and c) evaluating the linkage between the adjusted trait values and the markers based on alleles shared identically by descent. RESULTS: We applied our adjusted HE method and the standard HE method in S.A.G.E. to the sib-pair subset of the Framingham Heart Study distributed by Genetic Analysis Workshop 13 with systolic blood pressure as the quantitative trait. Both methods gave similar patterns for the LOD scores, and exhibited highest multipoint LOD scores near location 70 cM of chromosome 12. CONCLUSION: The adjusted HE method has two major advantages over the standard HE method used in S.A.G.E.: a) it has the capability to handle longitudinal data; b) it provides a more natural approach for adjusting the repeatedly measured covariates from each subject
- …