75 research outputs found
Provable Guarantees for Neural Networks via Gradient Feature Learning
Neural networks have achieved remarkable empirical performance, while the
current theoretical analysis is not adequate for understanding their success,
e.g., the Neural Tangent Kernel approach fails to capture their key feature
learning ability, while recent analyses on feature learning are typically
problem-specific. This work proposes a unified analysis framework for two-layer
networks trained by gradient descent. The framework is centered around the
principle of feature learning from gradients, and its effectiveness is
demonstrated by applications in several prototypical problems, such as mixtures
of Gaussians and parity functions. The framework also sheds light on
interesting network learning phenomena such as feature learning beyond kernels
and the lottery ticket hypothesis.Comment: NeurIPS 2023, 71 page
Towards Few-Shot Adaptation of Foundation Models via Multitask Finetuning
Foundation models have emerged as a powerful tool for many AI problems.
Despite the tremendous success of foundation models, effective adaptation to
new tasks, particularly those with limited labels, remains an open question and
lacks theoretical understanding. An emerging solution with recent success in
vision and NLP involves finetuning a foundation model on a selection of
relevant tasks, before its adaptation to a target task with limited labeled
samples. In this paper, we study the theoretical justification of this
multitask finetuning approach. Our theoretical analysis reveals that with a
diverse set of related tasks, this multitask finetuning leads to reduced error
in the target task, in comparison to directly adapting the same pretrained
model. We quantify the relationship between finetuning tasks and target tasks
by diversity and consistency metrics, and further propose a practical task
selection algorithm. We substantiate our theoretical claims with extensive
empirical evidence. Further, we present results affirming our task selection
algorithm adeptly chooses related finetuning tasks, providing advantages to the
model performance on target tasks. We believe our study shed new light on the
effective adaptation of foundation models to new tasks that lack abundant
labels. Our code is available at
https://github.com/OliverXUZY/Foudation-Model_Multitask.Comment: Published at ICLR 2024. 54 page
Towards Net-Zero Carbon Emissions in Network AI for 6G and Beyond
A global effort has been initiated to reduce the worldwide greenhouse gas
(GHG) emissions, primarily carbon emissions, by half by 2030 and reach net-zero
by 2050. The development of 6G must also be compliant with this goal.
Unfortunately, developing a sustainable and net-zero emission systems to meet
the users' fast growing demands on mobile services, especially smart services
and applications, may be much more challenging than expected. Particularly,
despite the energy efficiency improvement in both hardware and software
designs, the overall energy consumption and carbon emission of mobile networks
are still increasing at a tremendous speed. The growing penetration of
resource-demanding AI algorithms and solutions further exacerbate this
challenge. In this article, we identify the major emission sources and
introduce an evaluation framework for analyzing the lifecycle of network AI
implementations. A novel joint dynamic energy trading and task allocation
optimization framework, called DETA, has been introduced to reduce the overall
carbon emissions. We consider a federated edge intelligence-based network AI
system as a case study to verify the effectiveness of our proposed solution.
Experimental results based on a hardware prototype suggest that our proposed
solution can reduce carbon emissions of network AI systems by up to 74.9%.
Finally, open problems and future directions are discussed
Pivotal roles of CD8+ T cells restricted by MHC class I–like molecules in autoimmune diseases
Unlike T cells restricted by major histocompatibility complex (MHC) class Ia or class II molecules, T cells restricted by MHC class I–like molecules demonstrate properties of both innate and adaptive immunity and are therefore considered innate-like lymphocytes (ILLs). ILLs are believed to have immunoregulatory functions, but their roles in autoimmunity and defense against infections remain elusive. To study the properties of ILLs, we generated mice expressing only MHC class I–like molecules by crossing CIITA−/− with Kb−/−Db−/− mice. Surprisingly, these mice developed a lymphoproliferative syndrome and autoimmunity, most notably inflammatory bowel disease (IBD) and insulitis. The CD8+ ILLs in these mice exhibit a constitutively activated phenotype, and depletion of these cells abolished the autoimmune disorders. In addition, adoptive transfer of CD8+ ILLs from Kb−/−Db−/−CIITA−/− mice to Rag-1−/−pfn−/− mice also resulted in IBD and insulitis. These findings provide direct evidence that CD8+ ILLs are sufficient to initiate and mediate autoimmune diseases
Reasoning over the Air: A Reasoning-based Implicit Semantic-Aware Communication Framework
Semantic-aware communication is a novel paradigm that draws inspiration from
human communication focusing on the delivery of the meaning of messages. It has
attracted significant interest recently due to its potential to improve the
efficiency and reliability of communication and enhance users' QoE. Most
existing works focus on transmitting and delivering the explicit semantic
meaning that can be directly identified from the source signal. This paper
investigates the implicit semantic-aware communication in which the hidden
information that cannot be directly observed from the source signal must be
recognized and interpreted by the intended users. To this end, a novel implicit
semantic-aware communication (iSAC) architecture is proposed for representing,
communicating, and interpreting the implicit semantic meaning between source
and destination users. A projection-based semantic encoder is proposed to
convert the high-dimensional graphical representation of explicit semantics
into a low-dimensional semantic constellation space for efficient physical
channel transmission. To enable the destination user to learn and imitate the
implicit semantic reasoning process of source user, a generative adversarial
imitation learning-based solution, called G-RML, is proposed. Different from
existing communication solutions, the source user in G-RML does not focus only
on sending as much of the useful messages as possible; but, instead, it tries
to guide the destination user to learn a reasoning mechanism to map any
observed explicit semantics to the corresponding implicit semantics that are
most relevant to the semantic meaning. Compared to the existing solutions, our
proposed G-RML requires much less communication and computational resources and
scales well to the scenarios involving the communication of rich semantic
meanings consisting of a large number of concepts and relations.Comment: accepted at IEEE Transactions on Wireless Communication
Isolation of Mycobacterium tuberculosis complex (MTBC) from dairy cows in China
Eleven thousand five hundred and eighty non-blood samples from dairy cows were subjected to mycobacterium culture and genotyping. As a result, a total of 142 isolates of Mycobacterium tuberculosis complex (MBTC) were identified. Among them, 65 were Mycobacterium tuberculosis, while 77 Mycobacterium bovis. The genotype of M. tuberculosis strains was mainly Beijing family. In addition, the isolation rates of MTBC were 33.89% for lung lymph nodes, 2.81% for nasal swabs, and 3.95% for pharyngeal swabs from cattle positive to tuberculin skin test, respectively. This evidence implied that M. tuberculosis infection in cattle is a new risk to public health and should be paid more attention.Key words: Mycobacterium tuberculosis complex, cows, tuberculosis, zoonosis
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