What Is Unsupervised Learning?


The one point that I want to emphasize here is that the adjective "unsupervised" does not mean that these algorithms run by themselves without human supervision. It simply indicates the absence of a desired or ideal output corresponding to each input. An analyst (or a data scientist) who is training an unsupervised learning model has to exercise a similar kind of modeling discipline as does the one who is training a supervised model. Alternatively, an analyst who is training an unsupervised learning model can exercise a similar amount of control on the resulting output by configuring model parameters as does the one who is training a supervised model. While supervised algorithms derive a mapping function from x to y so as to accurately estimate the y's corresponding to new x's, unsupervised algorithms employ predefined distance/similarity functions to map the distribution of input x's.

EM and component-wise boosting for Hidden Markov Models: a machine-learning approach to capture-recapture


This study introduces statistical boosting for capture-mark-recapture (CMR) models. It is a shrinkage estimator that constrains the complexity of a CMR model in order to promote automatic variable-selection and avoid over-fitting. I discuss the philosophical similarities between boosting and AIC model-selection, and show through simulations that a boosted Cormack-Jolly-Seber model often out-performs AICc methods, in terms of estimating survival and abundance, yet yields qualitatively similar estimates. This new boosted CMR framework is highly extensible and could provide a rich, unified framework for addressing many topics in CMR, such as non-linear effects (splines and CART-like trees), individual-heterogeneity, and spatial components.

Churn Prediction with Apache Spark Machine Learning


We would like to determine which parameter values of the decision tree produce the best model. A common technique for model selection is k-fold cross validation, where the data is randomly split into k partitions. Each partition is used once as the testing data set, while the rest are used for training. Models are then generated using the training sets and evaluated with the testing sets, resulting in k model performance measurements. The average of the performance scores is often taken to be the overall score of the model, given its build parameters.

Variable selection vs Model selection


So I understand that variable selection is a part of model selection. But what exactly does model selection consist of? I ask this because I am reading an article Burnham & Anderson: AIC vs BIC where they talk about AIC and BIC in model selection. Reading this article I realize I have been thinking of'model selection' as'variable selection' (ref. An excerpt from the article where they talk about 12 models with increasing degrees of "generality" and these models show "tapering effects" (Figure 1) when KL-Information is plotted against the 12 models: DIFFERENT PHILOSOPHIES AND TARGET MODELS ... Despite that the target of BIC is a more general model than the target model for AIC, the model most often selected here by BIC will be less general than Model 7 unless n is very large.

How to build deep learning models with SAS


SAS supports the creation of deep neural network models. Examples of these models include convolutional neural networks, recurrent neural networks, feedforward neural networks and autoencoder neural networks. Let's examine in more detail how SAS creates deep learning models using SAS Visual Data Mining and Machine Learning. SAS Visual Mining and Machine Learning takes advantage of SAS Cloud Analytic Services (CAS) to perform what are referred to as CAS actions. You use CAS actions to load data, transform data, compute statistics, perform analytics and create output.