Neural network (machine learning)

This method is based on the idea of optimizing the network's parameters to minimize the difference, or empirical risk, between the predicted output and the actual target values in a given dataset.

It was used as a means of finding a good rough linear fit to a set of points by Legendre (1805) and Gauss (1795) for the prediction of planetary movement.

[7][8][9][10][11] Historically, digital computers such as the von Neumann model operate via the execution of explicit instructions with access to memory by a number of processors.

[16] In 1958, psychologist Frank Rosenblatt described the perceptron, one of the first implemented artificial neural networks,[17][18][19][20] funded by the United States Office of Naval Research.

This contributed to "the Golden Age of AI" fueled by the optimistic claims made by computer scientists regarding the ability of perceptrons to emulate human intelligence.

[10] Subsequent developments in hardware and hyperparameter tunings have made end-to-end stochastic gradient descent the currently dominant training technique.

The terminology "back-propagating errors" was actually introduced in 1962 by Rosenblatt,[24] but he did not know how to implement this, although Henry J. Kelley had a continuous precursor of backpropagation in 1960 in the context of control theory.

[48] Kunihiko Fukushima's convolutional neural network (CNN) architecture of 1979[36] also introduced max pooling,[49] a popular downsampling procedure for CNNs.

[82][83] In 2011, a CNN named DanNet[84][85] by Dan Ciresan, Ueli Meier, Jonathan Masci, Luca Maria Gambardella, and Jürgen Schmidhuber achieved for the first time superhuman performance in a visual pattern recognition contest, outperforming traditional methods by a factor of 3.

[88] In October 2012, AlexNet by Alex Krizhevsky, Ilya Sutskever, and Geoffrey Hinton[89] won the large-scale ImageNet competition by a significant margin over shallow machine learning methods.

[140] Given the memory matrix, W =||w(a,s)||, the crossbar self-learning algorithm in each iteration performs the following computation: The backpropagated value (secondary reinforcement) is the emotion toward the consequence situation.

The basic search algorithm is to propose a candidate model, evaluate it against a dataset, and use the results as feedback to teach the NAS network.

For example, machine learning has been used for classifying Android malware,[198] for identifying domains belonging to threat actors and for detecting URLs posing a security risk.

ANNs have been proposed as a tool to solve partial differential equations in physics[202][203][204] and simulate the properties of many-body open quantum systems.

For instance, graph neural networks (GNNs) have demonstrated their capability in scaling deep learning for the discovery of new stable materials by efficiently predicting the total energy of crystals.

This application underscores the adaptability and potential of ANNs in tackling complex problems beyond the realms of predictive modeling and artificial intelligence, opening new pathways for scientific discovery and innovation.

When the width of network approaches to infinity, the ANN is well described by its first order Taylor expansion throughout training, and so inherits the convergence behavior of affine models.

[152] Dean Pomerleau uses a neural network to train a robotic vehicle to drive on multiple types of roads (single lane, multi-lane, dirt, etc.

In 1997, Alexander Dewdney, a former Scientific American columnist, commented that as a result, artificial neural networks have a "something-for-nothing quality, one that imparts a peculiar aura of laziness and a distinct lack of curiosity about just how good these computing systems are.

[228] One response to Dewdney is that neural networks have been successfully used to handle many complex and diverse tasks, ranging from autonomously flying aircraft[229] to detecting credit card fraud to mastering the game of Go.

but also because you could create a successful net without understanding how it worked: the bunch of numbers that captures its behaviour would in all probability be "an opaque, unreadable table...valueless as a scientific resource".

[240] This imbalance can result in the model having inadequate representation and understanding of underrepresented groups, leading to discriminatory outcomes that exacerbate societal inequalities, especially in applications like facial recognition, hiring processes, and law enforcement.

[241][242] For example, in 2018, Amazon had to scrap a recruiting tool because the model favored men over women for jobs in software engineering due to the higher number of male workers in the field.

[243] Artificial neural networks (ANNs) have undergone significant advancements, particularly in their ability to model complex systems, handle large data sets, and adapt to various types of applications.

[244] This demonstrates the ability of ANNs to effectively process and interpret complex visual information, leading to advancements in fields ranging from automated surveillance to medical imaging.

Deep neural network architectures have introduced significant improvements in large vocabulary continuous speech recognition, outperforming traditional techniques.

They have enabled the development of models that can accurately translate between languages, understand the context and sentiment in textual data, and categorize text based on content.

Nevertheless, ongoing advancements suggest that ANNs continue to play a role in finance, offering valuable insights and enhancing risk management strategies.

They enhance diagnostic accuracy, especially by interpreting complex medical imaging for early disease detection, and by predicting patient outcomes for personalized treatment planning.

[245] Ongoing research is aimed at addressing remaining challenges such as data privacy and model interpretability, as well as expanding the scope of ANN applications in medicine.

An artificial neural network is an interconnected group of nodes, inspired by a simplification of neurons in a brain . Here, each circular node represents an artificial neuron and an arrow represents a connection from the output of one artificial neuron to the input of another.
Neuron and myelinated axon, with signal flow from inputs at dendrites to outputs at axon terminals
Confidence analysis of a neural network