99 research outputs found
A learning and masking approach to secure learning
Deep Neural Networks (DNNs) have been shown to be vulnerable against
adversarial examples, which are data points cleverly constructed to fool the
classifier. Such attacks can be devastating in practice, especially as DNNs are
being applied to ever increasing critical tasks like image recognition in
autonomous driving. In this paper, we introduce a new perspective on the
problem. We do so by first defining robustness of a classifier to adversarial
exploitation. Next, we show that the problem of adversarial example generation
can be posed as learning problem. We also categorize attacks in literature into
high and low perturbation attacks; well-known attacks like fast-gradient sign
method (FGSM) and our attack produce higher perturbation adversarial examples
while the more potent but computationally inefficient Carlini-Wagner (CW)
attack is low perturbation. Next, we show that the dual approach of the attack
learning problem can be used as a defensive technique that is effective against
high perturbation attacks. Finally, we show that a classifier masking method
achieved by adding noise to the a neural network's logit output protects
against low distortion attacks such as the CW attack. We also show that both
our learning and masking defense can work simultaneously to protect against
multiple attacks. We demonstrate the efficacy of our techniques by
experimenting with the MNIST and CIFAR-10 datasets
Sociocultural Norm Similarities and Differences via Situational Alignment and Explainable Textual Entailment
Designing systems that can reason across cultures requires that they are
grounded in the norms of the contexts in which they operate. However, current
research on developing computational models of social norms has primarily
focused on American society. Here, we propose a novel approach to discover and
compare descriptive social norms across Chinese and American cultures. We
demonstrate our approach by leveraging discussions on a Chinese Q&A platform
(Zhihu) and the existing SocialChemistry dataset as proxies for contrasting
cultural axes, align social situations cross-culturally, and extract social
norms from texts using in-context learning. Embedding Chain-of-Thought
prompting in a human-AI collaborative framework, we build a high-quality
dataset of 3,069 social norms aligned with social situations across Chinese and
American cultures alongside corresponding free-text explanations. To test the
ability of models to reason about social norms across cultures, we introduce
the task of explainable social norm entailment, showing that existing models
under 3B parameters have significant room for improvement in both automatic and
human evaluation. Further analysis of cross-cultural norm differences based on
our dataset shows empirical alignment with the social orientations framework,
revealing several situational and descriptive nuances in norms across these
cultures.Comment: EMNLP 2023 Main Conference (Long Paper
NormDial: A Comparable Bilingual Synthetic Dialog Dataset for Modeling Social Norm Adherence and Violation
Social norms fundamentally shape interpersonal communication. We present
NormDial, a high-quality dyadic dialogue dataset with turn-by-turn annotations
of social norm adherences and violations for Chinese and American cultures.
Introducing the task of social norm observance detection, our dataset is
synthetically generated in both Chinese and English using a human-in-the-loop
pipeline by prompting large language models with a small collection of
expert-annotated social norms. We show that our generated dialogues are of high
quality through human evaluation and further evaluate the performance of
existing large language models on this task. Our findings point towards new
directions for understanding the nuances of social norms as they manifest in
conversational contexts that span across languages and cultures.Comment: EMNLP 2023 Main Conference, Short Paper; Data at
https://github.com/Aochong-Li/NormDia
Transferrin-bound Yb2 uptake by U-87 MG cells and effect of Yb on proliferation of the cells
2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe
Toward a Critical Toponymy Framework for Named Entity Recognition: A Case Study of Airbnb in New York City
Critical toponymy examines the dynamics of power, capital, and resistance
through place names and the sites to which they refer. Studies here have
traditionally focused on the semantic content of toponyms and the top-down
institutional processes that produce them. However, they have generally ignored
the ways in which toponyms are used by ordinary people in everyday discourse,
as well as the other strategies of geospatial description that accompany and
contextualize toponymic reference. Here, we develop computational methods to
measure how cultural and economic capital shape the ways in which people refer
to places, through a novel annotated dataset of 47,440 New York City Airbnb
listings from the 2010s. Building on this dataset, we introduce a new named
entity recognition (NER) model able to identify important discourse categories
integral to the characterization of place. Our findings point toward new
directions for critical toponymy and to a range of previously understudied
linguistic signals relevant to research on neighborhood status, housing and
tourism markets, and gentrification.Comment: Accepted at EMNLP 2023 (main track
Disentangling superconducting and magnetic orders in NaFe_1-xNi_xAs using muon spin rotation
Muon spin rotation and relaxation studies have been performed on a "111"
family of iron-based superconductors NaFe_1-xNi_xAs. Static magnetic order was
characterized by obtaining the temperature and doping dependences of the local
ordered magnetic moment size and the volume fraction of the magnetically
ordered regions. For x = 0 and 0.4 %, a transition to a nearly-homogeneous long
range magnetically ordered state is observed, while for higher x than 0.4 %
magnetic order becomes more disordered and is completely suppressed for x = 1.5
%. The magnetic volume fraction continuously decreases with increasing x. The
combination of magnetic and superconducting volumes implies that a
spatially-overlapping coexistence of magnetism and superconductivity spans a
large region of the T-x phase diagram for NaFe_1-xNi_xAs . A strong reduction
of both the ordered moment size and the volume fraction is observed below the
superconducting T_C for x = 0.6, 1.0, and 1.3 %, in contrast to other iron
pnictides in which one of these two parameters exhibits a reduction below TC,
but not both. The suppression of magnetic order is further enhanced with
increased Ni doping, leading to a reentrant non-magnetic state below T_C for x
= 1.3 %. The reentrant behavior indicates an interplay between
antiferromagnetism and superconductivity involving competition for the same
electrons. These observations are consistent with the sign-changing s-wave
superconducting state, which is expected to appear on the verge of microscopic
coexistence and phase separation with magnetism. We also present a universal
linear relationship between the local ordered moment size and the
antiferromagnetic ordering temperature TN across a variety of iron-based
superconductors. We argue that this linear relationship is consistent with an
itinerant-electron approach, in which Fermi surface nesting drives
antiferromagnetic ordering.Comment: 20 pages, 14 figures, Correspondence should be addressed to Prof.
Yasutomo Uemura: [email protected]
Comparative effectiveness of dipeptidyl peptidase-4 (DPP-4) inhibitors and human glucagon-like peptide-1 (GLP-1) analogue as add-on therapies to sulphonylurea among diabetes patients in the Asia-Pacific region: a systematic review
The prevalence of diabetes mellitus is rising globally, and it induces a substantial public health burden to the healthcare systems. Its optimal control is one of the most significant challenges faced by physicians and policy-makers. Whereas some of the established oral hypoglycaemic drug classes like biguanide, sulphonylureas, thiazolidinediones have been extensively used, the newer agents like dipeptidyl peptidase-4 (DPP-4) inhibitors and the human glucagon-like peptide-1 (GLP-1) analogues have recently emerged as suitable options due to their similar efficacy and favorable side effect profiles. These agents are widely recognized alternatives to the traditional oral hypoglycaemic agents or insulin, especially in conditions where they are contraindicated or unacceptable to patients. Many studies which evaluated their clinical effects, either alone or as add-on agents, were conducted in Western countries. There exist few reviews on their effectiveness in the Asia-Pacific region. The purpose of this systematic review is to address the comparative effectiveness of these new classes of medications as add-on therapies to sulphonylurea drugs among diabetic patients in the Asia-Pacific countries. We conducted a thorough literature search of the MEDLINE and EMBASE from the inception of these databases to August 2013, supplemented by an additional manual search using reference lists from research studies, meta-analyses and review articles as retrieved by the electronic databases. A total of nine randomized controlled trials were identified and described in this article. It was found that DPP-4 inhibitors and GLP-1 analogues were in general effective as add-on therapies to existing sulphonylurea therapies, achieving HbA1c reductions by a magnitude of 0.59–0.90% and 0.77–1.62%, respectively. Few adverse events including hypoglycaemic attacks were reported. Therefore, these two new drug classes represent novel therapies with great potential to be major therapeutic options. Future larger-scale research should be conducted among other Asia-Pacific region to evaluate their efficacy in other ethnic groups
Needs, trends, and advances in scintillators for radiographic imaging and tomography
Scintillators are important materials for radiographic imaging and tomography
(RadIT), when ionizing radiations are used to reveal internal structures of
materials. Since its invention by R\"ontgen, RadIT now come in many modalities
such as absorption-based X-ray radiography, phase contrast X-ray imaging,
coherent X-ray diffractive imaging, high-energy X- and ray radiography
at above 1 MeV, X-ray computed tomography (CT), proton imaging and tomography
(IT), neutron IT, positron emission tomography (PET), high-energy electron
radiography, muon tomography, etc. Spatial, temporal resolution, sensitivity,
and radiation hardness, among others, are common metrics for RadIT performance,
which are enabled by, in addition to scintillators, advances in high-luminosity
accelerators and high-power lasers, photodetectors especially CMOS pixelated
sensor arrays, and lately data science. Medical imaging, nondestructive
testing, nuclear safety and safeguards are traditional RadIT applications.
Examples of growing or emerging applications include space, additive
manufacturing, machine vision, and virtual reality or `metaverse'. Scintillator
metrics such as light yield and decay time are correlated to RadIT metrics.
More than 160 kinds of scintillators and applications are presented during the
SCINT22 conference. New trends include inorganic and organic scintillator
heterostructures, liquid phase synthesis of perovskites and m-thick films,
use of multiphysics models and data science to guide scintillator development,
structural innovations such as photonic crystals, nanoscintillators enhanced by
the Purcell effect, novel scintillator fibers, and multilayer configurations.
Opportunities exist through optimization of RadIT with reduced radiation dose,
data-driven measurements, photon/particle counting and tracking methods
supplementing time-integrated measurements, and multimodal RadIT.Comment: 45 pages, 43 Figures, SCINT22 conference overvie
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