Digests » 68

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All Optical Neural Network with Nonlinear Activation Functions

Artificial neural networks (ANNs) have now been widely used for industry applications and also played more important roles in fundamental researches. Although most ANN hardware systems are electronically based, optical implementation is particularly attractive because of its intrinsic parallelism and low energy consumption. Here, we propose and demonstrate fully-functioned all optical neural networks (AONNs), in which linear operations are programmed by spatial light modulators and Fourier lenses, and optical nonlinear activation functions are realized with electromagnetically induced transparency in laser-cooled atoms. Moreover, all the errors from different optical neurons here are independent, thus the AONN could scale up to a larger system size with final error still maintaining in a similar level of a single neuron. We confirm its capability and feasibility in machine learning by successfully classifying the order and disorder phases of a typical statistic Ising model. The demonstrated AONN scheme can be used to construct various ANNs of different architectures with the intrinsic parallel computation at the speed of light.

What Is the Future of Chemistry?

Everybody has woken up in the morning haunted by the question “how relevant is what I do going to be in the future?”. In case of chemists, all of us wonder what is the future of chemistry sometimes.

Bi-Tempered Logistic Loss for Training Neural Nets with Noisy Data

The quality of models produced by machine learning (ML) algorithms directly depends on the quality of the training data, but real world datasets typically contain some amount of noise that introduces challenges for ML models. Noise in the dataset can take several forms from corrupted examples (e.g., lens flare in an image of a cat) to mislabelled examples from when the data was collected (e.g., an image of cat mislabelled as a flerken).

Understanding Convolutions

Imagine we drop a ball from some height onto the ground, where it only has one dimension of motion. How likely is it that a ball will go a distance cc if you drop it and then drop it again from above the point at which it landed?

How to Avoid Fallacies in Data

Anyone analyzing data will come across multiple challenges when it comes to drawing meaningful conclusions. Some of these have to do with the data itself – often it is incomplete, inconsistent, and sometimes not available at all. Assuming these challenges have been overcome, there are some other common pitfalls of data analysis to avoid.