197 research outputs found
Exploring Fairness in Pre-trained Visual Transformer based Natural and GAN Generated Image Detection Systems and Understanding the Impact of Image Compression in Fairness
It is not only sufficient to construct computational models that can
accurately classify or detect fake images from real images taken from a camera,
but it is also important to ensure whether these computational models are fair
enough or produce biased outcomes that can eventually harm certain social
groups or cause serious security threats. Exploring fairness in forensic
algorithms is an initial step towards correcting these biases. Since visual
transformers are recently being widely used in most image classification based
tasks due to their capability to produce high accuracies, this study tries to
explore bias in the transformer based image forensic algorithms that classify
natural and GAN generated images. By procuring a bias evaluation corpora, this
study analyzes bias in gender, racial, affective, and intersectional domains
using a wide set of individual and pairwise bias evaluation measures. As the
generalizability of the algorithms against image compression is an important
factor to be considered in forensic tasks, this study also analyzes the role of
image compression on model bias. Hence to study the impact of image compression
on model bias, a two phase evaluation setting is followed, where a set of
experiments is carried out in the uncompressed evaluation setting and the other
in the compressed evaluation setting
A Robust Approach Towards Distinguishing Natural and Computer Generated Images using Multi-Colorspace fused and Enriched Vision Transformer
The works in literature classifying natural and computer generated images are
mostly designed as binary tasks either considering natural images versus
computer graphics images only or natural images versus GAN generated images
only, but not natural images versus both classes of the generated images. Also,
even though this forensic classification task of distinguishing natural and
computer generated images gets the support of the new convolutional neural
networks and transformer based architectures that can give remarkable
classification accuracies, they are seen to fail over the images that have
undergone some post-processing operations usually performed to deceive the
forensic algorithms, such as JPEG compression, gaussian noise, etc. This work
proposes a robust approach towards distinguishing natural and computer
generated images including both, computer graphics and GAN generated images
using a fusion of two vision transformers where each of the transformer
networks operates in different color spaces, one in RGB and the other in YCbCr
color space. The proposed approach achieves high performance gain when compared
to a set of baselines, and also achieves higher robustness and generalizability
than the baselines. The features of the proposed model when visualized are seen
to obtain higher separability for the classes than the input image features and
the baseline features. This work also studies the attention map visualizations
of the networks of the fused model and observes that the proposed methodology
can capture more image information relevant to the forensic task of classifying
natural and generated images
Blacks is to Anger as Whites is to Joy? Understanding Latent Affective Bias in Large Pre-trained Neural Language Models
Groundbreaking inventions and highly significant performance improvements in
deep learning based Natural Language Processing are witnessed through the
development of transformer based large Pre-trained Language Models (PLMs). The
wide availability of unlabeled data within human generated data deluge along
with self-supervised learning strategy helps to accelerate the success of large
PLMs in language generation, language understanding, etc. But at the same time,
latent historical bias/unfairness in human minds towards a particular gender,
race, etc., encoded unintentionally/intentionally into the corpora harms and
questions the utility and efficacy of large PLMs in many real-world
applications, particularly for the protected groups. In this paper, we present
an extensive investigation towards understanding the existence of "Affective
Bias" in large PLMs to unveil any biased association of emotions such as anger,
fear, joy, etc., towards a particular gender, race or religion with respect to
the downstream task of textual emotion detection. We conduct our exploration of
affective bias from the very initial stage of corpus level affective bias
analysis by searching for imbalanced distribution of affective words within a
domain, in large scale corpora that are used to pre-train and fine-tune PLMs.
Later, to quantify affective bias in model predictions, we perform an extensive
set of class-based and intensity-based evaluations using various bias
evaluation corpora. Our results show the existence of statistically significant
affective bias in the PLM based emotion detection systems, indicating biased
association of certain emotions towards a particular gender, race, and
religion
REDAffectiveLM: Leveraging Affect Enriched Embedding and Transformer-based Neural Language Model for Readers' Emotion Detection
Technological advancements in web platforms allow people to express and share
emotions towards textual write-ups written and shared by others. This brings
about different interesting domains for analysis; emotion expressed by the
writer and emotion elicited from the readers. In this paper, we propose a novel
approach for Readers' Emotion Detection from short-text documents using a deep
learning model called REDAffectiveLM. Within state-of-the-art NLP tasks, it is
well understood that utilizing context-specific representations from
transformer-based pre-trained language models helps achieve improved
performance. Within this affective computing task, we explore how incorporating
affective information can further enhance performance. Towards this, we
leverage context-specific and affect enriched representations by using a
transformer-based pre-trained language model in tandem with affect enriched
Bi-LSTM+Attention. For empirical evaluation, we procure a new dataset REN-20k,
besides using RENh-4k and SemEval-2007. We evaluate the performance of our
REDAffectiveLM rigorously across these datasets, against a vast set of
state-of-the-art baselines, where our model consistently outperforms baselines
and obtains statistically significant results. Our results establish that
utilizing affect enriched representation along with context-specific
representation within a neural architecture can considerably enhance readers'
emotion detection. Since the impact of affect enrichment specifically in
readers' emotion detection isn't well explored, we conduct a detailed analysis
over affect enriched Bi-LSTM+Attention using qualitative and quantitative model
behavior evaluation techniques. We observe that compared to conventional
semantic embedding, affect enriched embedding increases ability of the network
to effectively identify and assign weightage to key terms responsible for
readers' emotion detection
Azimuthal and polar anchoring energies of aligning layers structured by nonlinear laser lithography
In spite of the fact that there are different techniques in the creation of
the high-quality liquid crystals (LCs) alignment by means of various surfaces,
the azimuthal and polar anchoring energies as well as the pre-tilt angle are
important parameters to all of them. Here, the modified by a certain manner
aligning layers, previously formed by nonlinear laser lithography (NLL), having
high-quality nano-periodic grooves on Ti surfaces, recently proposed for LC
alignment was studied. The change of the scanning speed of NLL in the process
of nano-structured Ti surfaces and their further modification by means of
ITO-coating, and deposition of polyimide film has enabled different aligning
layers, whose main characteristics, namely azimuthal and polar anchoring
energies, were measured. For the modified aligning layers, the dependencies of
the twist and pre-tilt angles for LC cells filled by nematic E7
({\Delta}{\epsilon} > 0) and MLC-6609 ({\Delta}{\epsilon} < 0) were obtained.
Also the contact angle for droplets of isotropic liquid (glycerol), and nematic
LCs was measured for the various values of the scanning speed during the laser
processing.Comment: 49 pages, 18 figure
Femtosecond laser written waveguides deep inside silicon
Photonic devices that can guide, transfer, or modulate light are highly desired in electronics and integrated silicon (Si) photonics. Here, we demonstrate for the first time, to the best of our knowledge, the creation of optical waveguides deep inside Si using femtosecond pulses at a central wavelength of 1.5 μm. To this end, we use 350 fs long, 2 μJ pulses with a repetition rate of 250 kHz from an Er-doped fiber laser, which we focused inside Si to create permanent modifications of the crystal. The position of the beam is accurately controlled with pump-probe imaging during fabrication. Waveguides that were 5.5 mm in length and 20 μm in diameter were created by scanning the focal position along the beam propagation axis. The fabricated waveguides were characterized with a continuous-wave laser operating at 1.5 μm. The refractive index change inside the waveguide was measured with optical shadowgraphy, yielding a value of 6 × 10−4, and by direct light coupling and far-field imaging, yielding a value of 3.5 × 10−4. The formation mechanism of the modification is discussed. © 2017 Optical Society of America
Optical waveguides written deep inside silicon by Femtosecond Laser
[No abstract available
Income in Adult Survivors of Childhood Cancer.
INTRODUCTION: Little is known about the impact of childhood cancer on the personal income of survivors. We compared income between survivors and siblings, and determined factors associated with income. METHODS: As part of the Swiss Childhood Cancer Survivor Study (SCCSS), a questionnaire was sent to survivors, aged ≥18 years, registered in the Swiss Childhood Cancer Registry (SCCR), diagnosed at age 4'500 CHF), even after we adjusted for socio-demographic and educational factors (OR = 0.46, p<0.001). Older age, male sex, personal and parental education, and number of working hours were associated with high income. Survivors of leukemia (OR = 0.40, p<0.001), lymphoma (OR = 0.63, p = 0.040), CNS tumors (OR = 0.22, p<0.001), bone tumors (OR = 0.24, p = 0.003) had a lower income than siblings. Survivors who had cranial irradiation, had a lower income than survivors who had no cranial irradiation (OR = 0.48, p = 0.006). DISCUSSION: Even after adjusting for socio-demographic characteristics, education and working hours, survivors of various diagnostic groups have lower incomes than siblings. Further research needs to identify the underlying causes
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