10 research outputs found
Making Linear MDPs Practical via Contrastive Representation Learning
It is common to address the curse of dimensionality in Markov decision
processes (MDPs) by exploiting low-rank representations. This motivates much of
the recent theoretical study on linear MDPs. However, most approaches require a
given representation under unrealistic assumptions about the normalization of
the decomposition or introduce unresolved computational challenges in practice.
Instead, we consider an alternative definition of linear MDPs that
automatically ensures normalization while allowing efficient representation
learning via contrastive estimation. The framework also admits
confidence-adjusted index algorithms, enabling an efficient and principled
approach to incorporating optimism or pessimism in the face of uncertainty. To
the best of our knowledge, this provides the first practical representation
learning method for linear MDPs that achieves both strong theoretical
guarantees and empirical performance. Theoretically, we prove that the proposed
algorithm is sample efficient in both the online and offline settings.
Empirically, we demonstrate superior performance over existing state-of-the-art
model-based and model-free algorithms on several benchmarks.Comment: ICML 2022. The first two authors contribute equall
DeepSeek-VL: Towards Real-World Vision-Language Understanding
We present DeepSeek-VL, an open-source Vision-Language (VL) Model designed
for real-world vision and language understanding applications. Our approach is
structured around three key dimensions:
We strive to ensure our data is diverse, scalable, and extensively covers
real-world scenarios including web screenshots, PDFs, OCR, charts, and
knowledge-based content, aiming for a comprehensive representation of practical
contexts. Further, we create a use case taxonomy from real user scenarios and
construct an instruction tuning dataset accordingly. The fine-tuning with this
dataset substantially improves the model's user experience in practical
applications. Considering efficiency and the demands of most real-world
scenarios, DeepSeek-VL incorporates a hybrid vision encoder that efficiently
processes high-resolution images (1024 x 1024), while maintaining a relatively
low computational overhead. This design choice ensures the model's ability to
capture critical semantic and detailed information across various visual tasks.
We posit that a proficient Vision-Language Model should, foremost, possess
strong language abilities. To ensure the preservation of LLM capabilities
during pretraining, we investigate an effective VL pretraining strategy by
integrating LLM training from the beginning and carefully managing the
competitive dynamics observed between vision and language modalities.
The DeepSeek-VL family (both 1.3B and 7B models) showcases superior user
experiences as a vision-language chatbot in real-world applications, achieving
state-of-the-art or competitive performance across a wide range of
visual-language benchmarks at the same model size while maintaining robust
performance on language-centric benchmarks. We have made both 1.3B and 7B
models publicly accessible to foster innovations based on this foundation
model.Comment: https://github.com/deepseek-ai/DeepSeek-V
DeepSeek LLM: Scaling Open-Source Language Models with Longtermism
The rapid development of open-source large language models (LLMs) has been
truly remarkable. However, the scaling law described in previous literature
presents varying conclusions, which casts a dark cloud over scaling LLMs. We
delve into the study of scaling laws and present our distinctive findings that
facilitate scaling of large scale models in two commonly used open-source
configurations, 7B and 67B. Guided by the scaling laws, we introduce DeepSeek
LLM, a project dedicated to advancing open-source language models with a
long-term perspective. To support the pre-training phase, we have developed a
dataset that currently consists of 2 trillion tokens and is continuously
expanding. We further conduct supervised fine-tuning (SFT) and Direct
Preference Optimization (DPO) on DeepSeek LLM Base models, resulting in the
creation of DeepSeek Chat models. Our evaluation results demonstrate that
DeepSeek LLM 67B surpasses LLaMA-2 70B on various benchmarks, particularly in
the domains of code, mathematics, and reasoning. Furthermore, open-ended
evaluations reveal that DeepSeek LLM 67B Chat exhibits superior performance
compared to GPT-3.5
Prevalence and drug resistance of Salmonella in dogs and cats in Xuzhou, China
Salmonellosis is a zoonotic disease, and Salmonella spp. can sometimes be found in dogs and cats, posing a risk to human health. In this study, the prevalence and antimicrobial susceptibility of faecal Salmonella were investigated in pet dogs and cats in Xuzhou, Jiangsu Province, China
Cyclic Response of Additive Manufactured 316L Stainless Steel : The Role of Cell Structures
We report the effect of cell structures on the fatigue behavior of additively manufactured (AM) 316L stainless steel (316LSS). Compared with the cell-free samples, the fatigue process of fully cellular samples only consists of steady and overload stages, without an initial softening stage. Moreover, the fully cellular sample possesses higher strength, lower cyclic softening rate and longer lifetime. Microscopic analyses show no difference in grain orientations, dimensions, and shapes. However, the fully cellular samples show planar dislocation structures, whereas the cell-free samples display wavy dislocation structures. The existence of cell structures promotes the activation of planar slip, delays strain localization, and ultimately enhances the fatigue performance of AM 316LSS.Funding: Swedish Governmental Agency for Innovation Systems (Vinnova)Vinnova [2016-05175]; Science Foundation Ireland (SFI)Science Foundation Ireland [16/RC/3872]; European Regional Development FundEuropean Commission; I-Form industry partners; Ji Hua Laboratroy [X210141TL210]; Center for Additive Manufacturing-metal (CAM2)</p
The Autophagy-Related Protein ATG8 Orchestrates Asexual Development and AFB1 Biosynthesis in <i>Aspergillus flavus</i>
Autophagy, a conserved cellular recycling process, plays a crucial role in maintaining homeostasis under stress conditions. It also regulates the development and virulence of numerous filamentous fungi. In this study, we investigated the specific function of ATG8, a reliable autophagic marker, in the opportunistic pathogen Aspergillus flavus. To investigate the role of atg8 in A. flavus, the deletion and complemented mutants of atg8 were generated according to the homologous recombination principle. Deletion of atg8 showed a significant decrease in conidiation, spore germination, and sclerotia formation compared to the WT and atg8C strains. Additionally, aflatoxin production was found severely impaired in the ∆atg8 mutant. The stress assays demonstrated that ATG8 was important for A. flavus response to oxidative stress. The fluorescence microscopy showed increased levels of reactive oxygen species in the ∆atg8 mutant cells, and the transcriptional result also indicated that genes related to the antioxidant system were significantly reduced in the ∆atg8 mutant. We further found that ATG8 participated in regulating the pathogenicity of A. flavus on crop seeds. These results revealed the biological role of ATG8 in A. flavus, which might provide a potential target for the control of A. flavus and AFB1 biosynthesis