331 research outputs found
Inefficiency of K-FAC for Large Batch Size Training
In stochastic optimization, using large batch sizes during training can
leverage parallel resources to produce faster wall-clock training times per
training epoch. However, for both training loss and testing error, recent
results analyzing large batch Stochastic Gradient Descent (SGD) have found
sharp diminishing returns, beyond a certain critical batch size. In the hopes
of addressing this, it has been suggested that the Kronecker-Factored
Approximate Curvature (\mbox{K-FAC}) method allows for greater scalability to
large batch sizes, for non-convex machine learning problems such as neural
network optimization, as well as greater robustness to variation in model
hyperparameters. Here, we perform a detailed empirical analysis of large batch
size training %of these two hypotheses, for both \mbox{K-FAC} and SGD,
evaluating performance in terms of both wall-clock time and aggregate
computational cost. Our main results are twofold: first, we find that both
\mbox{K-FAC} and SGD doesn't have ideal scalability behavior beyond a certain
batch size, and that \mbox{K-FAC} does not exhibit improved large-batch
scalability behavior, as compared to SGD; and second, we find that
\mbox{K-FAC}, in addition to requiring more hyperparameters to tune, suffers
from similar hyperparameter sensitivity behavior as does SGD. We discuss
extensive results using ResNet and AlexNet on \mbox{CIFAR-10} and SVHN,
respectively, as well as more general implications of our findings
The post-Paris approach to mitigating Arctic warming—perspectives from shipping emissions reduction
The availability of increased Arctic shipping as a consequence of sea ice decline is a regional issue that is closely linked with international climate governance and global governance of the maritime industry. Sea ice decline creates favorable circumstances for the development of merchant shipping, but is accompanied by increases in greenhouse gas emissions. Reduction of greenhouse gas emissions from the shipping industry is of utmost importance to prevent the destruction of the fragile Arctic ecosystem. This paper focuses on the core content of the Paris Agreement and suggests that the International Maritime Organization could guide the shipping industry to reach a fair agreement with states that includes market-based measures, capacity building, and voluntary actions of shipping companies as non-state actors
DreamTalk: When Expressive Talking Head Generation Meets Diffusion Probabilistic Models
Diffusion models have shown remarkable success in a variety of downstream
generative tasks, yet remain under-explored in the important and challenging
expressive talking head generation. In this work, we propose a DreamTalk
framework to fulfill this gap, which employs meticulous design to unlock the
potential of diffusion models in generating expressive talking heads.
Specifically, DreamTalk consists of three crucial components: a denoising
network, a style-aware lip expert, and a style predictor. The diffusion-based
denoising network is able to consistently synthesize high-quality audio-driven
face motions across diverse expressions. To enhance the expressiveness and
accuracy of lip motions, we introduce a style-aware lip expert that can guide
lip-sync while being mindful of the speaking styles. To eliminate the need for
expression reference video or text, an extra diffusion-based style predictor is
utilized to predict the target expression directly from the audio. By this
means, DreamTalk can harness powerful diffusion models to generate expressive
faces effectively and reduce the reliance on expensive style references.
Experimental results demonstrate that DreamTalk is capable of generating
photo-realistic talking faces with diverse speaking styles and achieving
accurate lip motions, surpassing existing state-of-the-art counterparts.Comment: Project Page: https://dreamtalk-project.github.i
A novel method of rapid detection for heavy metal copper ion via a specific copper chelator bathocuproinedisulfonic acid disodium salt
The extensive usage and production of copper may lead to toxic effects in organisms due to its accumulation in the environment. Traditional methods for copper detection are time consuming and infeasible for field usage. It is necessary to discover a real-time, rapid and economical method for detecting copper to ensure human health and environmental safety. Here we developed a colorimetric paper strip method and optimized spectrum method for rapid detection of copper ion based on the specific copper chelator bathocuproinedisulfonic acid disodium salt (BCS). Both biological assays and chemical methods verified the specificity of BCS for copper. The optimized reaction conditions were 50 mM Tris–HCl pH 7.4, 200 μM BCS, 1 mM ascorbate and less than 50 μM copper. The detection limit of the copper paper strip test was 0.5 mg/L by direct visual observation and the detection time was less than 1 min. The detection results of grape, peach, apple, spinach and cabbage by the optimized spectrum method were 0.91 μg/g, 0.87 μg/g, 0.19 μg/g, 1.37 μg/g and 0.39 μg/g, respectively. The paper strip assays showed that the copper contents of grape, peach, apple, spinach and cabbage were 0.8 mg/L, 0.9 mg/L, 0.2 mg/L, 1.3 mg/L and 0.5 mg/L, respectively. These results correlated well with those determined by inductively coupled plasma-mass spectrometry (ICP-MS). The visual detection limit of the paper strip based on Cu-BCS-AgNPs was 0.06 mg/L. Our study demonstrates the potential for on-site, rapid and cost-effective copper monitoring of foods and the environment
COMPUTE N-WAY DE-DUPLICATED REACH USING PRIVACY SAFE VECTOR OF COUNTS
Systems and methods for determining the union of the set of user identifiers across multiple publishers are described. Each publisher computing device can use a list of hash functions to hash the respective set of de-duplicated user identifiers. Each publisher can assemble a vector of counts using the respective hashed set of user identifiers, where each coordinate in the vector of counts corresponds to a select of bit positions from the hashed set of user identifiers. Each publisher can add noise to each of the vector of counts to enhance the privacy of the system. Each publisher can transmit the respective vector of counts to a server to compute the union of the multiset without exposing any private or protected information about the user identifiers to any third-party. The server can compute the union of the sets described by the vectors of counts from each of the publishers using at least one of the methods described herein
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