631 research outputs found
A Neural RDE-based model for solving path-dependent PDEs
The concept of the path-dependent partial differential equation (PPDE) was
first introduced in the context of path-dependent derivatives in financial
markets. Its semilinear form was later identified as a non-Markovian backward
stochastic differential equation (BSDE). Compared to the classical PDE, the
solution of a PPDE involves an infinite-dimensional spatial variable, making it
challenging to approximate, if not impossible. In this paper, we propose a
neural rough differential equation (NRDE)-based model to learn PPDEs, which
effectively encodes the path information through the log-signature feature
while capturing the fundamental dynamics. The proposed continuous-time model
for the PPDE solution offers the benefits of efficient memory usage and the
ability to scale with dimensionality. Several numerical experiments, provided
to validate the performance of the proposed model in comparison to the strong
baseline in the literature, are used to demonstrate its effectiveness
Lipidomic analysis to enhance the understanding of Chinese Hamster ovary cells
Chinese Hamster Ovary (CHO) cell lines are common hosts for the production of biotherapeutic proteins. Achieving high level of specific protein production by CHO cell lines remains a challenge. In order to address this issue, we are incorporating lipidomic analyses to study the role of lipids played in CHO-S cells.
In our study, we have applied chromatography (TLC) methods for lipid analysis in terms of lipid polarity. For polar lipids, 2-D HPTLC (2-dimensional high performance TLC) was used instead of conventional 1D- TLC by virtue of its high separation capacity. The eluting solvent system was optimized for the 1st and 2nd dimension, respectively. Neutral lipids were separated on 1-D HPTLC with the optimal elution solvent of hexane-diethyl ether-acetic acid. The lipid spots on the TLC plates were stained by 0.2% of 2,7-dichlorofluorescein dissolved in ethanol solution and illuminated with UV. Multiple lipid standards were also run to correctly identify the lipid spots and the fluorescence of lipid spots was semi-quantitatively measured with ImageJ.
By optimization of TLC conditions, the lipids of CHO-S cell line were separated successfully and the lipid contents were semi-quantified. From neutral lipids result, we observed high level of certain lipids in CHO-S cell lines. We will further investigate which lipid play a key role in various cell processes
Dynamic Sparse Training via Balancing the Exploration-Exploitation Trade-off
Over-parameterization of deep neural networks (DNNs) has shown high
prediction accuracy for many applications. Although effective, the large number
of parameters hinders its popularity on resource-limited devices and has an
outsize environmental impact. Sparse training (using a fixed number of nonzero
weights in each iteration) could significantly mitigate the training costs by
reducing the model size. However, existing sparse training methods mainly use
either random-based or greedy-based drop-and-grow strategies, resulting in
local minimal and low accuracy. In this work, we consider the dynamic sparse
training as a sparse connectivity search problem and design an exploitation and
exploration acquisition function to escape from local optima and saddle points.
We further design an acquisition function and provide the theoretical
guarantees for the proposed method and clarify its convergence property.
Experimental results show that sparse models (up to 98\% sparsity) obtained by
our proposed method outperform the SOTA sparse training methods on a wide
variety of deep learning tasks. On VGG-19 / CIFAR-100, ResNet-50 / CIFAR-10,
ResNet-50 / CIFAR-100, our method has even higher accuracy than dense models.
On ResNet-50 / ImageNet, the proposed method has up to 8.2\% accuracy
improvement compared to SOTA sparse training methods
The FlySpeech Audio-Visual Speaker Diarization System for MISP Challenge 2022
This paper describes the FlySpeech speaker diarization system submitted to
the second \textbf{M}ultimodal \textbf{I}nformation Based \textbf{S}peech
\textbf{P}rocessing~(\textbf{MISP}) Challenge held in ICASSP 2022. We develop
an end-to-end audio-visual speaker diarization~(AVSD) system, which consists of
a lip encoder, a speaker encoder, and an audio-visual decoder. Specifically, to
mitigate the degradation of diarization performance caused by separate
training, we jointly train the speaker encoder and the audio-visual decoder. In
addition, we leverage the large-data pretrained speaker extractor to initialize
the speaker encoder
Evaluating Open-QA Evaluation
This study focuses on the evaluation of the Open Question Answering (Open-QA)
task, which can directly estimate the factuality of large language models
(LLMs). Current automatic evaluation methods have shown limitations, indicating
that human evaluation still remains the most reliable approach. We introduce a
new task, Evaluating QA Evaluation (QA-Eval) and the corresponding dataset
EVOUNA, designed to assess the accuracy of AI-generated answers in relation to
standard answers within Open-QA. Our evaluation of these methods utilizes
human-annotated results to measure their performance. Specifically, the work
investigates methods that show high correlation with human evaluations, deeming
them more reliable. We also discuss the pitfalls of current methods and methods
to improve LLM-based evaluators. We believe this new QA-Eval task and
corresponding dataset EVOUNA will facilitate the development of more effective
automatic evaluation tools and prove valuable for future research in this area.
All resources are available at \url{https://github.com/wangcunxiang/QA-Eval}
and it is under the Apache-2.0 License
Spherically Symmetric Noncommutative Spacetime via Exotic Atomic Transitions
In discussing non-commutative spacetime, the generally studied
-Poincare model is inconsistent with bound states. In this Letter, we
develop the formalism and study the phenomenology of another model
by the twisted permutation algebra and extend the
Pauli Exclusion Principle(PEP) into non-commutative spacetime. The model also
implies time quantization and can avoid UV/IR mixing. Applying it to atomic
systems, we show that the model with newly induced phase factors can cause
exotic transitions consisting of three electrons in the 1S orbit of atoms. The
transition rate is derived, and the upper bound of non-commutative parameter
is thus set by utilizing data from the low-energy and low-background
experiments, where strongest constraint eV
at 90\% C.L. is given by XENONnT, with the time quanta , equivalent to twenty times smaller than the Planck time.Comment: 6 pages, 4 figure
Neurogenesis Dynamics-inspired Spiking Neural Network Training Acceleration
Biologically inspired Spiking Neural Networks (SNNs) have attracted
significant attention for their ability to provide extremely energy-efficient
machine intelligence through event-driven operation and sparse activities. As
artificial intelligence (AI) becomes ever more democratized, there is an
increasing need to execute SNN models on edge devices. Existing works adopt
weight pruning to reduce SNN model size and accelerate inference. However,
these methods mainly focus on how to obtain a sparse model for efficient
inference, rather than training efficiency. To overcome these drawbacks, in
this paper, we propose a Neurogenesis Dynamics-inspired Spiking Neural Network
training acceleration framework, NDSNN. Our framework is computational
efficient and trains a model from scratch with dynamic sparsity without
sacrificing model fidelity. Specifically, we design a new drop-and-grow
strategy with decreasing number of non-zero weights, to maintain extreme high
sparsity and high accuracy. We evaluate NDSNN using VGG-16 and ResNet-19 on
CIFAR-10, CIFAR-100 and TinyImageNet. Experimental results show that NDSNN
achieves up to 20.52\% improvement in accuracy on Tiny-ImageNet using ResNet-19
(with a sparsity of 99\%) as compared to other SOTA methods (e.g., Lottery
Ticket Hypothesis (LTH), SET-SNN, RigL-SNN). In addition, the training cost of
NDSNN is only 40.89\% of the LTH training cost on ResNet-19 and 31.35\% of the
LTH training cost on VGG-16 on CIFAR-10
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