395 research outputs found
Berndt-Type Integrals of Order Three and Series Associated with Jacobi Elliptic Functions
In this paper, we first establish explicit evaluations of six classes of
hyperbolic sums by special values of the Gamma function by using the tools of
the Fourier series expansions and the Maclaurin series expansions of a few
Jacobi elliptic functions developed in our previous paper. Then, using the
method of contour integrations involving hyperbolic and trigonometric
functions, we establish explicit evaluations of two families of Berndt-type
integrals of order three by special values of the Gamma function. Furthermore,
we present some interesting consequences and illustrative examples.Comment: 19 pages. arXiv admin note: text overlap with arXiv:2301.0821
Explicit Planning Helps Language Models in Logical Reasoning
Language models have been shown to perform remarkably well on a wide range of
natural language processing tasks. In this paper, we propose a novel system
that uses language models to perform multi-step logical reasoning. Our system
incorporates explicit planning into its inference procedure, thus able to make
more informed reasoning decisions at each step by looking ahead into their
future effects. In our experiments, our full system significantly outperforms
other competing systems. On a multiple-choice question answering task, our
system performs competitively compared to GPT-3-davinci despite having only
around 1.5B parameters. We conduct several ablation studies to demonstrate that
explicit planning plays a crucial role in the system's performance
Kernel meets sieve: transformed hazards models with sparse longitudinal covariates
We study the transformed hazards model with time-dependent covariates
observed intermittently for the censored outcome. Existing work assumes the
availability of the whole trajectory of the time-dependent covariates, which is
unrealistic. We propose to combine kernel-weighted log-likelihood and sieve
maximum log-likelihood estimation to conduct statistical inference. The method
is robust and easy to implement. We establish the asymptotic properties of the
proposed estimator and contribute to a rigorous theoretical framework for
general kernel-weighted sieve M-estimators. Numerical studies corroborate our
theoretical results and show that the proposed method performs favorably over
existing methods. Applying to a COVID-19 study in Wuhan illustrates the
practical utility of our method
Statistical Guarantees of Generative Adversarial Networks for Distribution Estimation
Generative Adversarial Networks (GANs) have achieved great success in
unsupervised learning. Despite the remarkable empirical performance, there are
limited theoretical understandings on the statistical properties of GANs. This
paper provides statistical guarantees of GANs for the estimation of data
distributions which have densities in a H\"{o}lder space. Our main result shows
that, if the generator and discriminator network architectures are properly
chosen (universally for all distributions with H\"{o}lder densities), GANs are
consistent estimators of the data distributions under strong discrepancy
metrics, such as the Wasserstein distance. To our best knowledge, this is the
first statistical theory of GANs for H\"{o}lder densities. In comparison with
existing works, our theory requires minimum assumptions on data distributions.
Our generator and discriminator networks utilize general weight matrices and
the non-invertible ReLU activation function, while many existing works only
apply to invertible weight matrices and invertible activation functions. In our
analysis, we decompose the error into a statistical error and an approximation
error by a new oracle inequality, which may be of independent interest
Adaptive Distribution Calibration for Few-Shot Learning with Hierarchical Optimal Transport
Few-shot classification aims to learn a classifier to recognize unseen
classes during training, where the learned model can easily become over-fitted
based on the biased distribution formed by only a few training examples. A
recent solution to this problem is calibrating the distribution of these few
sample classes by transferring statistics from the base classes with sufficient
examples, where how to decide the transfer weights from base classes to novel
classes is the key. However, principled approaches for learning the transfer
weights have not been carefully studied. To this end, we propose a novel
distribution calibration method by learning the adaptive weight matrix between
novel samples and base classes, which is built upon a hierarchical Optimal
Transport (H-OT) framework. By minimizing the high-level OT distance between
novel samples and base classes, we can view the learned transport plan as the
adaptive weight information for transferring the statistics of base classes.
The learning of the cost function between a base class and novel class in the
high-level OT leads to the introduction of the low-level OT, which considers
the weights of all the data samples in the base class. Experimental results on
standard benchmarks demonstrate that our proposed plug-and-play model
outperforms competing approaches and owns desired cross-domain generalization
ability, indicating the effectiveness of the learned adaptive weights
Numerical Analysis of Reinforced Concrete Piles under Blast Loads
Pile foundations are commonly used as foundation systems for high-rise buildings and bridges. This paper uses a fully coupled three dimensional numerical modelling procedure to study the performance of pile foundations subjected to ground shocks induced by surface explosions. The comprehensive numerical model includes the pile, surrounding soil, air and the explosive. Appropriate material models are incorporated and dynamic non-linear analysis is carried out using finite element techniques. The soil in which the pile is buried could influence the blast performance of the pile. A parametric study is hence carried out to evaluate the effects of soil properties of density, friction angle, cohesion and Poisson’s ratio on the blast performance of the pile. It is found that density and cohesion of soil have significant effects on the deflection of the pile under blast loading. Poisson’s ratio has some effect, but effect of the soil friction angle is not very significant. The findings of this study will serve as a benchmark reference for future analysis and design of pile foundations to blast loading
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