11,493 research outputs found
Neural response development during distributional learning.
We investigated online electrophysiological components of distributional learning, specifically of tones by listeners of a non-tonal language. German listeners were presented with a bimodal distribution of syllables with lexical tones from a synthesized continuum based on Cantonese level tones. Tones were presented in sets of four standards (within-category tokens) followed by a deviant (across-category token). Mismatch negativity (MMN) was measured. Earlier behavioral data showed that exposure to this bimodal distribution improved both categorical perception and perceptual acuity for level tones [1]. In the present study we present analyses of the electrophysiological response recorded during this exposure, i.e., the development of the MMN response during distributional learning. This development over time is analyzed using Generalized Additive Mixed Models and results showed that the MMN amplitude increased for both within- and across-category tokens, reflecting higher perceptual acuity accompanying category formation. This is evidence that learners zooming in on phonological categories undergo neural changes associated with more accurate phonetic perception.This research was also supported by a Research Networking grant (ESF) NetwordS No. 6609 to NB and a Leiden University AMT Individual Researcher Grant to JSN
Crop Yield Prediction Using Deep Neural Networks
Crop yield is a highly complex trait determined by multiple factors such as
genotype, environment, and their interactions. Accurate yield prediction
requires fundamental understanding of the functional relationship between yield
and these interactive factors, and to reveal such relationship requires both
comprehensive datasets and powerful algorithms. In the 2018 Syngenta Crop
Challenge, Syngenta released several large datasets that recorded the genotype
and yield performances of 2,267 maize hybrids planted in 2,247 locations
between 2008 and 2016 and asked participants to predict the yield performance
in 2017. As one of the winning teams, we designed a deep neural network (DNN)
approach that took advantage of state-of-the-art modeling and solution
techniques. Our model was found to have a superior prediction accuracy, with a
root-mean-square-error (RMSE) being 12% of the average yield and 50% of the
standard deviation for the validation dataset using predicted weather data.
With perfect weather data, the RMSE would be reduced to 11% of the average
yield and 46% of the standard deviation. We also performed feature selection
based on the trained DNN model, which successfully decreased the dimension of
the input space without significant drop in the prediction accuracy. Our
computational results suggested that this model significantly outperformed
other popular methods such as Lasso, shallow neural networks (SNN), and
regression tree (RT). The results also revealed that environmental factors had
a greater effect on the crop yield than genotype.Comment: 9 pages, Presented at 2018 INFORMS Conference on Business Analytics
and Operations Research (Baltimore, MD, USA). One of the winning solutions to
the 2018 Syngenta Crop Challeng
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