228 research outputs found
Identification-robust inference for the LATE with high-dimensional covariates
This paper investigates the local average treatment effect (LATE) with
high-dimensional covariates, irrespective of the strength of identification. We
propose a novel test statistic for the high-dimensional LATE and demonstrate
that our test has uniformly correct asymptotic size. By employing the
double/debiased machine learning method for nuisance parameter estimation, we
develop easy-to-implement algorithms for inference and confidence interval
calculation of the high-dimensional LATE. Simulations indicate that our test is
robust against both weak identification and high dimensionality concerning size
control and power performance, outperforming other conventional tests. Applying
the proposed method to railroad and population data to study the effect of
railroad access on urban population growth, we observe that our methodology
yields point estimates for the railroad access coefficients that are smaller in
magnitude and confidence intervals that are by 49% to 92% shorter depending on
specifications, when compared to the conventional results.Comment: 52pages, 2 figure
Few-shot classification in Named Entity Recognition Task
For many natural language processing (NLP) tasks the amount of annotated data
is limited. This urges a need to apply semi-supervised learning techniques,
such as transfer learning or meta-learning. In this work we tackle Named Entity
Recognition (NER) task using Prototypical Network - a metric learning
technique. It learns intermediate representations of words which cluster well
into named entity classes. This property of the model allows classifying words
with extremely limited number of training examples, and can potentially be used
as a zero-shot learning method. By coupling this technique with transfer
learning we achieve well-performing classifiers trained on only 20 instances of
a target class.Comment: In proceedings of the 34th ACM/SIGAPP Symposium on Applied Computin
Deep point-based scene labeling with depth mapping and geometric patch feature encoding
This paper presents a deep CNN approach for point-based semantic scene labeling. This is challenging because 3D point clouds do not have a canonical domain and can have complex geometry and substantial variation of sampling densities. We propose a novel framework where the convolution operator is defined on depth maps around sampled points, which captures characteristics of local surface regions. We introduce Depth Mapping (DM) and Reverse Depth Mapping (RDM) operators to transform between the point domain and the depth map domain. Our depth map based convolution is computationally efficient, robust to scene scales and sampling densities, and can capture rich surface characteristics. We further propose to augment each point with feature encoding of the local geometric patches resulted from multi-method through patch pooling network (PPN). The patch features provide complementary information and are fed into our classification network to achieve semantic segmentation
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