25,946 research outputs found
Paricle identification at VAMOS++ with machine learning techniques
Multi-nucleon transfer reaction between 136Xe beam and 198Pt target was performed using the VAMOS++ spectrometer at GANIL to study the structure of n-rich nuclei around N=126. Unambiguous charge state identification was obtained by combining two supervised machine learning methods, deep neural network (DNN) and positional correction using a gradient-boosting decision tree (GBDT). The new method reduced the complexity of the kinetic energy calibration and outperformed the conventional method improving the charge state resolution by 8%
A LightGBM-Based EEG Analysis Method for Driver Mental States Classification
Fatigue driving can easily lead to road traffic accidents and bring great harm to individuals and families. Recently, electroencephalography-
(EEG-) based physiological and brain activities for fatigue detection have been increasingly investigated.
However, how to find an effective method or model to timely and efficiently detect the mental states of drivers still remains a
challenge. In this paper, we combine common spatial pattern (CSP) and propose a light-weighted classifier, LightFD, which is
based on gradient boosting framework for EEG mental states identification. ,e comparable results with traditional classifiers,
such as support vector machine (SVM), convolutional neural network (CNN), gated recurrent unit (GRU), and large margin
nearest neighbor (LMNN), show that the proposed model could achieve better classification performance, as well as the decision
efficiency. Furthermore, we also test and validate that LightFD has better transfer learning performance in EEG classification of
driver mental states. In summary, our proposed LightFD classifier has better performance in real-time EEG mental state
prediction, and it is expected to have broad application prospects in practical brain-computer interaction (BCI)
Robust Decision Trees Against Adversarial Examples
Although adversarial examples and model robustness have been extensively
studied in the context of linear models and neural networks, research on this
issue in tree-based models and how to make tree-based models robust against
adversarial examples is still limited. In this paper, we show that tree based
models are also vulnerable to adversarial examples and develop a novel
algorithm to learn robust trees. At its core, our method aims to optimize the
performance under the worst-case perturbation of input features, which leads to
a max-min saddle point problem. Incorporating this saddle point objective into
the decision tree building procedure is non-trivial due to the discrete nature
of trees --- a naive approach to finding the best split according to this
saddle point objective will take exponential time. To make our approach
practical and scalable, we propose efficient tree building algorithms by
approximating the inner minimizer in this saddle point problem, and present
efficient implementations for classical information gain based trees as well as
state-of-the-art tree boosting models such as XGBoost. Experimental results on
real world datasets demonstrate that the proposed algorithms can substantially
improve the robustness of tree-based models against adversarial examples
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