66 research outputs found
A Novel Data Augmentation Technique for Out-of-Distribution Sample Detection using Compounded Corruptions
Modern deep neural network models are known to erroneously classify
out-of-distribution (OOD) test data into one of the in-distribution (ID)
training classes with high confidence. This can have disastrous consequences
for safety-critical applications. A popular mitigation strategy is to train a
separate classifier that can detect such OOD samples at the test time. In most
practical settings OOD examples are not known at the train time, and hence a
key question is: how to augment the ID data with synthetic OOD samples for
training such an OOD detector? In this paper, we propose a novel Compounded
Corruption technique for the OOD data augmentation termed CnC. One of the major
advantages of CnC is that it does not require any hold-out data apart from the
training set. Further, unlike current state-of-the-art (SOTA) techniques, CnC
does not require backpropagation or ensembling at the test time, making our
method much faster at inference. Our extensive comparison with 20 methods from
the major conferences in last 4 years show that a model trained using CnC based
data augmentation, significantly outperforms SOTA, both in terms of OOD
detection accuracy as well as inference time. We include a detailed post-hoc
analysis to investigate the reasons for the success of our method and identify
higher relative entropy and diversity of CnC samples as probable causes. We
also provide theoretical insights via a piece-wise decomposition analysis on a
two-dimensional dataset to reveal (visually and quantitatively) that our
approach leads to a tighter boundary around ID classes, leading to better
detection of OOD samples. Source code link: https://github.com/cnc-oodComment: 16 pages of the main text, and supplemental material. Accepted in
Research Track ECML'22. Project webpage: https://cnc-ood.github.io
Complete Nondiagonal Reflection Matrices of RSOS/SOS and Hard Hexagon Models
In this paper we compute the most general nondiagonal reflection matrices of
the RSOS/SOS models and hard hexagon model using the boundary Yang-Baxter
equations. We find new one-parameter family of reflection matrices for the RSOS
model in addition to the previous result without any parameter. We also find
three classes of reflection matrices for the SOS model, which has one or two
parameters. For the hard hexagon model which can be mapped to RSOS(5) model by
folding four RSOS heights into two, the solutions can be obtained similarly
with a main difference in the boundary unitarity conditions. Due to this, the
reflection matrices can have two free parameters. We show that these extra
terms can be identified with the `decorated' solutions. We also generalize the
hard hexagon model by `folding' the RSOS heights of the general RSOS(p) model
and show that they satisfy the integrability conditions such as the Yang-
Baxter and boundary Yang-Baxter equations. These models can be solved using the
results for the RSOS models.Comment: 18pages,Late
The "topological" charge for the finite XX quantum chain
It is shown that an operator (in general non-local) commutes with the
Hamiltonian describing the finite XX quantum chain with certain non-diagonal
boundary terms. In the infinite volume limit this operator gives the
"topological" charge.Comment: 5 page
Quantum boundary currents for nonsimply-laced Toda theories
We study the quantum integrability of nonsimply--laced affine Toda theories
defined on the half--plane and explicitly construct the first nontrivial
higher--spin charges in specific examples. We find that, in contradistinction
to the classical case, addition of total derivative terms to the "bulk" current
plays a relevant role for the quantum boundary conservation.Comment: 11 pages, latex, no figure
Quantum integrability in two-dimensional systems with boundary
In this paper we consider affine Toda systems defined on the half-plane and
study the issue of integrability, i.e. the construction of higher-spin
conserved currents in the presence of a boundary perturbation. First at the
classical level we formulate the problem within a Lax pair approach which
allows to determine the general structure of the boundary perturbation
compatible with integrability. Then we analyze the situation at the quantum
level and compute corrections to the classical conservation laws in specific
examples. We find that, except for the sinh-Gordon model, the existence of
quantum conserved currents requires a finite renormalization of the boundary
potential.Comment: latex file, 18 pages, 1 figur
Boundary Flows in general Coset Theories
In this paper we study the boundary effects for off-critical integrable field
theories which have close analogs with integrable lattice models. Our models
are the coset conformal field theories
perturbed by integrable boundary and bulk operators. The boundary interactions
are encoded into the boundary reflection matrix. Using the TBA method, we
verify the flows of the conformal BCs by computing the boundary entropies.
These flows of the BCs have direct interpretations for the fusion RSOS lattice
models. For super CFTs () we show that these flows are possible only for
the Neveu-Schwarz sector and are consistent with the lattice results. The
models we considered cover a wide class of integrable models. In particular, we
show how the the impurity spin is screened by electrons for the -channel
Kondo model by taking limit. We also study the problem using an
independent method based on the boundary roaming TBA. Our numerical results are
consistent with the boundary CFTs and RSOS TBA analysis.Comment: 22 pages, 3 postscript figure file
Inter edge Tunneling in Quantum Hall Line Junctions
We propose a scenario to understand the puzzling features of the recent
experiment by Kang and coworkers on tunneling between laterally coupled quantum
Hall liquids by modeling the system as a pair of coupled chiral Luttinger
liquid with a point contact tunneling center. We show that for filling factors
the effects of the Coulomb interactions move the system deep into
strong tunneling regime, by reducing the magnitude of the Luttinger parameter
, leading to the appearance of a zero-bias differential conductance peak of
magnitude at zero temperature. The abrupt appearance of the zero
bias peak as the filling factor is increased past a value ,
and its gradual disappearance thereafter can be understood as a crossover
controlled by the main energy scales of this system: the bias voltage , the
crossover scale , and the temperature . The low height of the zero bias
peak observed in the experiment, and its broad finite width,
can be understood naturally within this picture. Also, the abrupt reappearance
of the zero-bias peak for can be explained as an effect caused
by spin reversed electrons, \textit{i. e.} if the 2DEG is assumed to have a
small polarization near . We also predict that as the temperature is
lowered should decrease, and the width of zero-bias peak should become
wider. This picture also predicts the existence of similar zero bias peak in
the spin tunneling conductance near for .Comment: 17 pages, 8 figure
Films and critical pedagogy in management education: A tourism studies context
This article examines and critically assesses the role of films in the practice of critical pedagogy in undergraduate management education, using tourism studies as a context. Utilising online focus groups, it aims to gain an in-depth knowledge and understanding of the role of films as an effective pedagogical medium in enhancing experiential approaches to learning. It argues that films play an important role in facilitating critical analyses of the studied phenomenon, illustrating and problematising abstract concepts and ideas, as well as in facilitating students’ ability to discern multiple and alternative discourses about management. The findings highlight the role of films in context-specific critical engagement with the studied content and in stimulating emotionality in learning development, thereby enhancing deep approaches to learning. Emotional responses, even negative ones, prove to be critical in engaging with intellectual and critical reflection after watching films. The findings yield new and empirical insights into the pedagogic use of films in management education, thereby contributing to some of the goals of critical management studies
Trust, contract and relationship development
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