928 research outputs found
Studying the Applicability of Generative Adversarial Networks on HEp-2 Cell Image Augmentation
The Anti-Nuclear Antibodies (ANAs) testing is the primary serological diagnosis screening test for autoimmune diseases. ANAs testing is conducted mainly by the Indirect Immunofluorescence (IIF) on Human Epithelial cell-substrate (HEp-2) protocol. However, due to its high variability, human-subjectivity, and low throughput, there is an insistent need to develop an efficient Computer-Aided Diagnosis system (CADs) to automate this protocol. Many recently proposed Convolutional Neural Networks (CNNs) demonstrated promising results in HEp-2 cell image classification, which is the main task of the HE-p2 IIF protocol. However, the lack of large labeled datasets is still the main challenge in this field. This work provides a detailed study of the applicability of using generative adversarial networks (GANs) algorithms as an augmentation method. Different types of GANs were employed to synthesize HEp-2 cell images to address the data scarcity problem. For systematic comparison, empirical quantitative metrics were implemented to evaluate different GAN models' performance of learning the real data representations. The results of this work showed that though the high visual similarity with the real images, GANs' capacity to generate diverse data is still limited. This deficiency in the generated data diversity is found to be of a crucial impact when used as a standalone method for augmentation. However, combining limited-size GANs-generated data with classic augmentation improves the classification accuracy across different variants of CNNs. Our results demonstrated a competitive performance for the overall classification accuracy and the mean class accuracy of the HEp-2 cell image classification task
Boosted Top Quark Tagging and Polarization Measurement using Machine Learning
Machine learning techniques are used treating jets as images to explore the
performance of boosted top quark tagging. Tagging performances are studied in
both hadronic and leptonic channels of top quark decay, employing a
convolutional neutral network (CNN) based technique along with boosted decision
trees (BDT). This computer vision approach is also applied to distinguish
between left and right polarized top quarks. In this context, an experimentally
measurable asymmetry variable is proposed to estimate the polarization. Results
indicates that the CNN based classifier is more sensitive to top quark
polarization than the standard kinematic variables. It is observed that the
overall tagging performance in the leptonic channel is better than the hadronic
case, and the former also serves as a better probe for studying polarization
Unfolding Mixed-Symmetry Fields in AdS and the BMV Conjecture: I. General Formalism
We present some generalities of unfolded on-shell dynamics that are useful in
analysing the BMV conjecture for mixed-symmetry fields in constantly curved
backgrounds. In particular we classify the Lorentz-covariant Harish-Chandra
modules generated from primary Weyl tensors of arbitrary mass and shape, and in
backgrounds with general values of the cosmological constant. We also discuss
the unfolded notion of local degrees of freedom in theories with and without
gravity and with and without massive deformation parameters, using the language
of Weyl zero-form modules and their duals.Comment: Corrected typos, references added, two figures, some remarks and two
subsections added for clarit
Topological symmetry, spin liquids and CFT duals of Polyakov model with massless fermions
We prove the absence of a mass gap and confinement in the Polyakov model with
massless complex fermions in any representation of the gauge group. A
topological shift symmetry protects the masslessness of one dual
photon. This symmetry emerges in the IR as a consequence of the Callias index
theorem and abelian duality. For matter in the fundamental representation, the
infrared limits of this class of theories interpolate between weakly and
strongly coupled conformal field theory (CFT) depending on the number of
flavors, and provide an infinite class of CFTs in dimensions. The long
distance physics of the model is same as certain stable spin liquids. Altering
the topology of the adjoint Higgs field by turning it into a compact scalar
does not change the long distance dynamics in perturbation theory, however,
non-perturbative effects lead to a mass gap for the gauge fluctuations. This
provides conceptual clarity to many subtle issues about compact QED
discussed in the context of quantum magnets, spin liquids and phase fluctuation
models in cuprate superconductors. These constructions also provide new
insights into zero temperature gauge theory dynamics on and
. The confined versus deconfined long distance dynamics is
characterized by a discrete versus continuous topological symmetry.Comment: 30 pages, 1 figure, 1 tabl
On the refined counting of graphs on surfaces
Ribbon graphs embedded on a Riemann surface provide a useful way to describe
the double line Feynman diagrams of large N computations and a variety of other
QFT correlator and scattering amplitude calculations, e.g in MHV rules for
scattering amplitudes, as well as in ordinary QED. Their counting is a special
case of the counting of bi-partite embedded graphs. We review and extend
relevant mathematical literature and present results on the counting of some
infinite classes of bi-partite graphs. Permutation groups and representations
as well as double cosets and quotients of graphs are useful mathematical tools.
The counting results are refined according to data of physical relevance, such
as the structure of the vertices, faces and genus of the embedded graph. These
counting problems can be expressed in terms of observables in three-dimensional
topological field theory with S_d gauge group which gives them a topological
membrane interpretation.Comment: 57 pages, 12 figures; v2: Typos corrected; references adde
A Cross-Residual Learning for Image Recognition
ResNets and its variants play an important role in various fields of image
recognition. This paper gives another variant of ResNets, a kind of
cross-residual learning networks called C-ResNets, which has less computation
and parameters than ResNets. C-ResNets increases the information interaction
between modules by densifying jumpers and enriches the role of jumpers. In
addition, some meticulous designs on jumpers and channels counts can further
reduce the resource consumption of C-ResNets and increase its classification
performance. In order to test the effectiveness of C-ResNets, we use the same
hyperparameter settings as fine-tuned ResNets in the experiments.
We test our C-ResNets on datasets MNIST, FashionMnist, CIFAR-10, CIFAR-100,
CALTECH-101 and SVHN. Compared with fine-tuned ResNets, C-ResNets not only
maintains the classification performance, but also enormously reduces the
amount of calculations and parameters which greatly save the utilization rate
of GPUs and GPU memory resources. Therefore, our C-ResNets is competitive and
viable alternatives to ResNets in various scenarios. Code is available at
https://github.com/liangjunhello/C-ResNetComment: After being added into fine training tricks and several key
components from the current SOTA, the performance of C-ResNet may can be
greatly improve
DCTRGAN: Improving the Precision of Generative Models with Reweighting
Significant advances in deep learning have led to more widely used and
precise neural network-based generative models such as Generative Adversarial
Networks (GANs). We introduce a post-hoc correction to deep generative models
to further improve their fidelity, based on the Deep neural networks using the
Classification for Tuning and Reweighting (DCTR) protocol. The correction takes
the form of a reweighting function that can be applied to generated examples
when making predictions from the simulation. We illustrate this approach using
GANs trained on standard multimodal probability densities as well as
calorimeter simulations from high energy physics. We show that the weighted GAN
examples significantly improve the accuracy of the generated samples without a
large loss in statistical power. This approach could be applied to any
generative model and is a promising refinement method for high energy physics
applications and beyond.Comment: 14 pages, 8 figure
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