1,613 research outputs found
Constraints on the neutrino mass and mass hierarchy from cosmological observations
Considering the mass splitting between three active neutrinos, we represent
the new constraints on the sum of neutrino mass by updating the
anisotropic analysis of Baryon Acoustic Oscillation (BAO) scale in the CMASS
and LOWZ galaxy samples from Data Release 12 of the SDSS-III Baryon Oscillation
Spectroscopic Survey (BOSS DR12). Combining the BAO data of 6dFGS, MGS, LOWZ
and CMASS with ~2015 data of temperature anisotropy and
polarizations of Cosmic Microwave Background (CMB), we find that the
C.L. upper bounds on refer to eV for
normal hierarchy (NH), eV for inverted hierarchy
(IH) and eV for degenerate hierarchy (DH)
respectively, and the normal hierarchy is slightly preferred than the inverted
one (). In
addition, the additional relativistic degrees of freedom and massive sterile
neutrinos are neither favored at present.Comment: 12 pages, 3 tables, 1 figure; refs adde
Beamforming and Power Splitting Designs for AN-aided Secure Multi-user MIMO SWIPT Systems
In this paper, an energy harvesting scheme for a multi-user
multiple-input-multiple-output (MIMO) secrecy channel with artificial noise
(AN) transmission is investigated. Joint optimization of the transmit
beamforming matrix, the AN covariance matrix, and the power splitting ratio is
conducted to minimize the transmit power under the target secrecy rate, the
total transmit power, and the harvested energy constraints. The original
problem is shown to be non-convex, which is tackled by a two-layer
decomposition approach. The inner layer problem is solved through semi-definite
relaxation, and the outer problem, on the other hand, is shown to be a single-
variable optimization that can be solved by one-dimensional (1- D) line search.
To reduce computational complexity, a sequential parametric convex
approximation (SPCA) method is proposed to find a near-optimal solution. The
work is then extended to the imperfect channel state information case with
norm-bounded channel errors. Furthermore, tightness of the relaxation for the
proposed schemes are validated by showing that the optimal solution of the
relaxed problem is rank-one. Simulation results demonstrate that the proposed
SPCA method achieves the same performance as the scheme based on 1-D but with
much lower complexity.Comment: 12 pages, 6 figures, submitted for possible publicatio
ExClaim: Explainable Neural Claim Verification Using Rationalization
With the advent of deep learning, text generation language models have
improved dramatically, with text at a similar level as human-written text. This
can lead to rampant misinformation because content can now be created cheaply
and distributed quickly. Automated claim verification methods exist to validate
claims, but they lack foundational data and often use mainstream news as
evidence sources that are strongly biased towards a specific agenda. Current
claim verification methods use deep neural network models and complex
algorithms for a high classification accuracy but it is at the expense of model
explainability. The models are black-boxes and their decision-making process
and the steps it took to arrive at a final prediction are obfuscated from the
user. We introduce a novel claim verification approach, namely: ExClaim, that
attempts to provide an explainable claim verification system with foundational
evidence. Inspired by the legal system, ExClaim leverages rationalization to
provide a verdict for the claim and justifies the verdict through a natural
language explanation (rationale) to describe the model's decision-making
process. ExClaim treats the verdict classification task as a question-answer
problem and achieves a performance of 0.93 F1 score. It provides subtasks
explanations to also justify the intermediate outcomes. Statistical and
Explainable AI (XAI) evaluations are conducted to ensure valid and trustworthy
outcomes. Ensuring claim verification systems are assured, rational, and
explainable is an essential step toward improving Human-AI trust and the
accessibility of black-box systems.Comment: Published at 2022 IEEE 29th ST
Evaluating and Incentivizing Diverse Data Contributions in Collaborative Learning
For a federated learning model to perform well, it is crucial to have a
diverse and representative dataset. However, the data contributors may only be
concerned with the performance on a specific subset of the population, which
may not reflect the diversity of the wider population. This creates a tension
between the principal (the FL platform designer) who cares about global
performance and the agents (the data collectors) who care about local
performance. In this work, we formulate this tension as a game between the
principal and multiple agents, and focus on the linear experiment design
problem to formally study their interaction. We show that the statistical
criterion used to quantify the diversity of the data, as well as the choice of
the federated learning algorithm used, has a significant effect on the
resulting equilibrium. We leverage this to design simple optimal federated
learning mechanisms that encourage data collectors to contribute data
representative of the global population, thereby maximizing global performance
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