416 research outputs found
Engineering Photon Delocalization in a Rabi Dimer with a Dissipative Bath
A Rabi dimer is used to model a recently reported circuit quantum
electrodynamics system composed of two coupled transmission-line resonators
with each coupled to one qubit. In this study, a phonon bath is adopted to
mimic the multimode micromechanical resonators and is coupled to the qubits in
the Rabi dimer. The dynamical behavior of the composite system is studied by
the Dirac-Frenkel time-dependent variational principle combined with the
multiple Davydov D ans\"{a}tze. Initially all the photons are pumped into
the left resonator, and the two qubits are in the down state coupled with the
phonon vacuum. In the strong qubit-photon coupling regime, the photon dynamics
can be engineered by tuning the qubit-bath coupling strength and
photon delocalization is achieved by increasing . In the absence of
dissipation, photons are localized in the initial resonator. Nevertheless, with
moderate qubit-bath coupling, photons are delocalized with quasiequilibration
of the photon population in two resonators at long times. In this case, high
frequency bath modes are activated by interacting with depolarized qubits. For
strong dissipation, photon delocalization is achieved via frequent
photon-hopping within two resonators and the qubits are suppressed in their
initial down state.Comment: 11 pages, 11 figure
Synthesis of ultrathin platinum nanoplates for enhanced oxygen reduction activity.
Ultrathin Pt nanostructures exposing controlled crystal facets are highly desirable for their superior activity and cost-effectiveness in the electrocatalytic oxygen reduction reaction (ORR), and they are conventionally synthesized by epitaxial growth of Pt on a limited range of templates, such as Pd nanocrystals, resulting in a high cost and less structural diversity of the ultrathin Pt nanostructures. To solve this problem, we demonstrate that ultrathin Pt nanostructures can be synthesized by templating conveniently available Ag nanocrystals without involving galvanic replacement, which enables a much-reduced cost and controllable new morphologies, such as ultrathin Pt nanoplates that expose the {111} facets. The resulting ultrathin Pt nanoplates are ∼1-2 nm in thickness, which show an ∼22-fold increase in specific activity (5.3 mA cm-2), an ∼9.5-fold increase in mass activity (1.62 A mg-1) and significantly enhanced catalytic stability in the ORR, compared with the commercial Pt/C catalyst. We believe this strategy opens a door to a highly extendable family of ultrathin noble metal nanostructures, thus promising excellent activity and stability in a broad range of catalytic applications
Efficient RLHF: Reducing the Memory Usage of PPO
Reinforcement Learning with Human Feedback (RLHF) has revolutionized language
modeling by aligning models with human preferences. However, the RL stage,
Proximal Policy Optimization (PPO), requires over 3x the memory of Supervised
Fine-Tuning (SFT), making it infeasible to use for most practitioners. To
address this issue, we present a comprehensive analysis the memory usage,
performance, and training time of memory-savings techniques for PPO. We
introduce Hydra-RLHF by first integrating the SFT and Reward models and then
dynamically turning LoRA "off" during training. Our experiments show: 1. Using
LoRA during PPO reduces its memory usage to be smaller than SFT while improving
alignment across four public benchmarks, and 2. Hydra-PPO reduces the latency
per sample of LoRA-PPO by up to 65% while maintaining its performance. Our
results demonstrate that Hydra-PPO is a simple and promising solution for
enabling more widespread usage of RLHF
Causal-CoG: A Causal-Effect Look at Context Generation for Boosting Multi-modal Language Models
While Multi-modal Language Models (MLMs) demonstrate impressive multimodal
ability, they still struggle on providing factual and precise responses for
tasks like visual question answering (VQA). In this paper, we address this
challenge from the perspective of contextual information. We propose Causal
Context Generation, Causal-CoG, which is a prompting strategy that engages
contextual information to enhance precise VQA during inference. Specifically,
we prompt MLMs to generate contexts, i.e, text description of an image, and
engage the generated contexts for question answering. Moreover, we investigate
the advantage of contexts on VQA from a causality perspective, introducing
causality filtering to select samples for which contextual information is
helpful. To show the effectiveness of Causal-CoG, we run extensive experiments
on 10 multimodal benchmarks and show consistent improvements, e.g., +6.30% on
POPE, +13.69% on Vizwiz and +6.43% on VQAv2 compared to direct decoding,
surpassing existing methods. We hope Casual-CoG inspires explorations of
context knowledge in multimodal models, and serves as a plug-and-play strategy
for MLM decoding
Noise reduction optimization of sound sensor based on a Conditional Generation Adversarial Network
To address the problems in the traditional speech signal noise elimination methods, such as the residual noise, poor real-time performance and narrow applications a new method is proposed to eliminate network voice noise based on deep learning of conditional generation adversarial network. In terms of the perceptual evaluation of speech quality (PESQ) and shorttime objective intelligibility measure (STOI) functions used as the loss function in the neural network, which were used as the loss function in the neural network, the flexibility of the whole network was optimized, and the training process of the model simplified. The experimental results indicate that, under the noisy environment, especially in a restaurant, the proposed noise reduction scheme improves the STOI score by 26.23% and PESQ score by 17.18%, respectively, compared with the traditional Wiener noise reduction algorithm. Therefore, the sound sensor\u27s noise reduction scheme through our approach has achieved a remarkable noise reduction effect, more useful information transmission, and stronger practicability
Adapting LLM Agents Through Communication
Recent advancements in large language models (LLMs) have shown potential for
human-like agents. To help these agents adapt to new tasks without extensive
human supervision, we propose the Learning through Communication (LTC)
paradigm, a novel training approach enabling LLM agents to improve continuously
through interactions with their environments and other agents. Recent
advancements in large language models (LLMs) have shown potential for
human-like agents. To help these agents adapt to new tasks without extensive
human supervision, we propose the Learning through Communication (LTC)
paradigm, a novel training approach enabling LLM agents to improve continuously
through interactions with their environments and other agents. Through
iterative exploration and PPO training, LTC empowers the agent to assimilate
short-term experiences into long-term memory. To optimize agent interactions
for task-specific learning, we introduce three structured communication
patterns: Monologue, Dialogue, and Analogue-tailored for common tasks such as
decision-making, knowledge-intensive reasoning, and numerical reasoning. We
evaluated LTC on three datasets: ALFWorld (decision-making), HotpotQA
(knowledge-intensive reasoning), and GSM8k (numerical reasoning). On ALFWorld,
it exceeds the instruction tuning baseline by 12% in success rate. On HotpotQA,
LTC surpasses the instruction-tuned LLaMA-7B agent by 5.1% in EM score, and it
outperforms the instruction-tuned 9x larger PaLM-62B agent by 0.6%. On GSM8k,
LTC outperforms the CoT-Tuning baseline by 3.6% in accuracy. The results
showcase the versatility and efficiency of the LTC approach across diverse
domains. We will open-source our code to promote further development of the
community.Comment: Preprin
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