1,464 research outputs found
Inelastic Strength Behavior of Horizontally Curved Composite I-Girder Bridge Structural Systems
This research investigates the strength behavior of horizontally curved composite I-girder bridge structural systems, and the representation of this behavior by the AASHTO (2004b) LRFD provisions. The primary focus is on the design of a representative curved composite I-girder bridge tested at the FHWA Turner-Fairbank Highway Research Center, interpretation of the results from the testing of this bridge, including correlation with extensive linear and nonlinear finite element analysis solutions, and parametric extension of the test results using finite element models similar to those validated against the physical tests. These studies support the potential liberalization of the AASHTO (2004b) provisions by the use of a plastic moment based resistance, reduced by flange lateral bending effects, for composite I-girders in positive bending.Ph.D.Committee Chair: Dr. Donald W. White; Committee Member: Dr. Kenneth M. Will; Committee Member: Dr. Olivier Bauchau; Committee Member: Dr. Rami Haj-Ali; Committee Member: Dr. Roberto T. Leo
FlexRound: Learnable Rounding based on Element-wise Division for Post-Training Quantization
Post-training quantization (PTQ) has been gaining popularity for the
deployment of deep neural networks on resource-limited devices since unlike
quantization-aware training, neither a full training dataset nor end-to-end
training is required at all. As PTQ schemes based on reconstructing each layer
or block output turn out to be effective to enhance quantized model
performance, recent works have developed algorithms to devise and learn a new
weight-rounding scheme so as to better reconstruct each layer or block output.
In this work, we propose a simple yet effective new weight-rounding mechanism
for PTQ, coined FlexRound, based on element-wise division instead of typical
element-wise addition such that FlexRound enables jointly learning a common
quantization grid size as well as a different scale for each pre-trained
weight. Thanks to the reciprocal rule of derivatives induced by element-wise
division, FlexRound is inherently able to exploit pre-trained weights when
updating their corresponding scales, and thus, flexibly quantize pre-trained
weights depending on their magnitudes. We empirically validate the efficacy of
FlexRound on a wide range of models and tasks. To the best of our knowledge,
our work is the first to carry out comprehensive experiments on not only image
classification and natural language understanding but also natural language
generation, assuming a per-tensor uniform PTQ setting. Moreover, we
demonstrate, for the first time, that large language models can be efficiently
quantized, with only a negligible impact on performance compared to
half-precision baselines, achieved by reconstructing the output in a
block-by-block manner.Comment: Accepted to ICML 202
Refining Generative Process with Discriminator Guidance in Score-based Diffusion Models
The proposed method, Discriminator Guidance, aims to improve sample
generation of pre-trained diffusion models. The approach introduces a
discriminator that gives explicit supervision to a denoising sample path
whether it is realistic or not. Unlike GANs, our approach does not require
joint training of score and discriminator networks. Instead, we train the
discriminator after score training, making discriminator training stable and
fast to converge. In sample generation, we add an auxiliary term to the
pre-trained score to deceive the discriminator. This term corrects the model
score to the data score at the optimal discriminator, which implies that the
discriminator helps better score estimation in a complementary way. Using our
algorithm, we achive state-of-the-art results on ImageNet 256x256 with FID 1.83
and recall 0.64, similar to the validation data's FID (1.68) and recall (0.66).
We release the code at https://github.com/alsdudrla10/DG.Comment: International Conference on Machine Learning (ICML23
Memory-Efficient Fine-Tuning of Compressed Large Language Models via sub-4-bit Integer Quantization
Large language models (LLMs) face the challenges in fine-tuning and
deployment due to their high memory demands and computational costs. While
parameter-efficient fine-tuning (PEFT) methods aim to reduce the memory usage
of the optimizer state during fine-tuning, the inherent size of pre-trained LLM
weights continues to be a pressing concern. Even though quantization techniques
are widely proposed to ease memory demands and accelerate LLM inference, most
of these techniques are geared towards the deployment phase. To bridge this
gap, this paper presents Parameter-Efficient and Quantization-aware Adaptation
(PEQA) - a simple yet effective method that combines the advantages of PEFT
with quantized LLMs. By updating solely the quantization scales, PEQA can be
directly applied to quantized LLMs, ensuring seamless task transitions.
Parallel to existing PEFT methods, PEQA significantly reduces the memory
overhead associated with the optimizer state. Furthermore, it leverages the
advantages of quantization to substantially reduce model sizes. Even after
fine-tuning, the quantization structure of a PEQA-tuned LLM remains intact,
allowing for accelerated inference on the deployment stage. We employ
PEQA-tuning for task-specific adaptation on LLMs with up to 65 billion
parameters. To assess the logical reasoning and language comprehension of
PEQA-tuned LLMs, we fine-tune low-bit quantized LLMs using a instruction
dataset. Our results show that even when LLMs are quantized to below 4-bit
precision, their capabilities in language modeling, few-shot in-context
learning, and comprehension can be resiliently restored to (or even improved
over) their full-precision original performances with PEQA.Comment: Published at NeurIPS 2023. Camera-ready versio
Protective Effects of Emodin and Chrysophanol Isolated from Marine Fungus Aspergillus sp. on Ethanol-Induced Toxicity in HepG2/CYP2E1 Cells
Alcohol-induced liver injury progresses from fatty infiltration followed by a harmful cause of inflammation leading to an irreversible damage. In this study, two compounds (emodin and chrysophanol) isolated from marine fungus Aspergillus sp. were examined for their protective effects against ethanol-induced toxicity in vitro. Ethanol-induced HepG2/CYP2E1 cells were treated with the compounds at various concentrations, and the results showed that there was a dose-dependent decrease of gamma-glutamyl transpeptidase (GGT) activity and increase of glutathione (GSH) in the culture media with an increase in cell viability. Furthermore, the protective effects of the compounds were evaluated by protein expression levels of GGT, GSH, and CYP2E1 using Western blot. Among the compounds, emodin addressed to the ethanol-induced cytotoxicity more effectively compared to the chrysophanol. It could be suggested that emodin isolated from this genus would be a potential candidate for attenuating ethanol induced liver damage for further industrial applications such as functional food and pharmaceutical developments
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