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  2. Learning vector quantization - Wikipedia

    en.wikipedia.org/wiki/Learning_vector_quantization

    The position of this so-called winner prototype is then adapted, i.e. the winner is moved closer if it correctly classifies the data point or moved away if it classifies the data point incorrectly. An advantage of LVQ is that it creates prototypes that are easy to interpret for experts in the respective application domain. [ 2 ]

  3. Vector quantization - Wikipedia

    en.wikipedia.org/wiki/Vector_quantization

    Vector quantization (VQ) is a classical quantization technique from signal processing that allows the modeling of probability density functions by the distribution of prototype vectors. Developed in the early 1980s by Robert M. Gray , it was originally used for data compression .

  4. Ventilation/perfusion ratio - Wikipedia

    en.wikipedia.org/wiki/Ventilation/perfusion_ratio

    This matching may be assessed in the lung as a whole, or in individual or in sub-groups of gas-exchanging units in the lung. On the other side Ventilation-perfusion mismatch is the term used when the ventilation and the perfusion of a gas exchanging unit are not matched. The actual values in the lung vary depending on the position within the lung.

  5. Q-learning - Wikipedia

    en.wikipedia.org/wiki/Q-learning

    Distributional Q-learning is a variant of Q-learning which seeks to model the distribution of returns rather than the expected return of each action. It has been observed to facilitate estimate by deep neural networks and can enable alternative control methods, such as risk-sensitive control.

  6. Matching pursuit - Wikipedia

    en.wikipedia.org/wiki/Matching_pursuit

    Matching pursuit should represent the signal by just a few atoms, such as the three at the centers of the clearly visible ellipses. Matching pursuit (MP) is a sparse approximation algorithm which finds the "best matching" projections of multidimensional data onto the span of an over-complete (i.e., redundant) dictionary .

  7. Variational autoencoder - Wikipedia

    en.wikipedia.org/wiki/Variational_autoencoder

    In machine learning, a variational autoencoder (VAE) is an artificial neural network architecture introduced by Diederik P. Kingma and Max Welling. [1] It is part of the families of probabilistic graphical models and variational Bayesian methods.

  8. Propensity score matching - Wikipedia

    en.wikipedia.org/wiki/Propensity_score_matching

    The insights behind the use of matching still hold but should be applied with other matching methods; propensity scores also have other productive uses in weighting and doubly robust estimation. Like other matching procedures, PSM estimates an average treatment effect from observational data. The key advantages of PSM were, at the time of its ...

  9. Similarity learning - Wikipedia

    en.wikipedia.org/wiki/Similarity_learning

    Similarity learning is closely related to distance metric learning. Metric learning is the task of learning a distance function over objects. A metric or distance function has to obey four axioms: non-negativity, identity of indiscernibles, symmetry and subadditivity (or the triangle inequality). In practice, metric learning algorithms ignore ...