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 Statistical Learning


Linear Regression

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Regression is an Algorithm of the Supervised Learning model. When the output or the dependent feature is continuous and labeled then, we apply the Regression Algorithm. Regression is used to find the relation or equation between the Independent variables and the output variable. E.g., given below, we have variable x₁, x₂, ….,xₙ, which contribute towards the output of variable y. We have to find a relation between x variables and dependent variable y.


Must Have Data Science Skills That You Should Learn - Statanalytica

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Data science skills contains several subject skills such as it contains skills in relation to math, science, business communication, statistics & English. Having skills in a diversified area enables you to crunch with financial functional and non- functional activities to influence decision making concepts. Accordingly, it can be said that data science skills are those which contain technical as well as non-technical skills. Data science skills help businesses to make decisions as it breaks the gap of communication between numbers and action in the real world. Data scientists must have skills of communication, and an understanding of its implication on businesses along with recommendation.


The 8 Best Predictive Modeling Books on Our Reading List

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Find powerful new insights in your data; discover machine learning with R." "The process of developing predictive models includes many stages. Most resources focus on the modeling algorithms but neglect other critical aspects of the modeling process. This book describes techniques for finding the best representations of predictors for modeling and for nding the best subset of predictors for improving model performance. A variety of example data sets are used to illustrate the techniques along with R programs for reproducing the results." "Kattamuri Sarma's Predictive Modeling with SAS Enterprise Miner: Practical Solutions for Business Applications, Third Edition, will show you how to develop and test predictive models quickly using SAS Enterprise Miner.


The Cost of Privacy in Generalized Linear Models: Algorithms and Minimax Lower Bounds

arXiv.org Machine Learning

The trade-off between differential privacy and statistical accuracy in generalized linear models (GLMs) is studied. We propose differentially private algorithms for parameter estimation in both low-dimensional and high-dimensional sparse GLMs and characterize their statistical performance. We establish privacy-constrained minimax lower bounds for GLMs, which imply that the proposed algorithms are rate-optimal up to logarithmic factors in sample size. The lower bounds are obtained via a novel technique, which is based on Stein's Lemma and generalizes the tracing attack technique for privacy-constrained lower bounds. This lower bound argument can be of independent interest as it is applicable to general parametric models. Simulated and real data experiments are conducted to demonstrate the numerical performance of our algorithms.


A fast randomized incremental gradient method for decentralized non-convex optimization

arXiv.org Machine Learning

We study decentralized non-convex finite-sum minimization problems described over a network of nodes, where each node possesses a local batch of data samples. We propose a single-timescale first-order randomized incremental gradient method, termed as GT-SAGA. GT-SAGA is computationally efficient since it evaluates only one component gradient per node per iteration and achieves provably fast and robust performance by leveraging node-level variance reduction and network-level gradient tracking. For general smooth non-convex problems, we show almost sure and mean-squared convergence to a first-order stationary point and describe regimes of practical significance where GT-SAGA achieves a network-independent convergence rate and outperforms the existing approaches respectively. When the global cost function further satisfies the Polyak-Lojaciewisz condition, we show that GT-SAGA exhibits global linear convergence to an optimal solution in expectation and describe regimes of practical interest where the performance is network-independent and improves upon the existing work. Numerical experiments based on real-world datasets are included to highlight the behavior and convergence aspects of the proposed method.


Overcoming Negative Transfer: A Survey

arXiv.org Machine Learning

Transfer learning (TL) tries to utilize data or knowledge from one or more source domains to facilitate the learning in a target domain. It is particularly useful when the target domain has few or no labeled data, due to annotation expense, privacy concerns, etc. Unfortunately, the effectiveness of TL is not always guaranteed. Negative transfer (NT), i.e., the source domain data/knowledge cause reduced learning performance in the target domain, has been a long-standing and challenging problem in TL. Various approaches to overcome NT have been proposed in the literature. However, there has not been a systematic survey on overcoming NT. This paper fills the gap, by categorizing and reviewing near 100 approaches for combating NT, from four perspectives: source data quality, target data quality, domain divergence, and integrated algorithms. NT in related fields, e.g., multi-task learning, multilingual models, and lifelong learning, is also discussed.


Generalization error in high-dimensional perceptrons: Approaching Bayes error with convex optimization

arXiv.org Machine Learning

We consider a commonly studied supervised classification of a synthetic dataset whose labels are generated by feeding a one-layer neural network with random iid inputs. We study the generalization performances of standard classifiers in the high-dimensional regime where $\alpha=n/d$ is kept finite in the limit of a high dimension $d$ and number of samples $n$. Our contribution is three-fold: First, we prove a formula for the generalization error achieved by $\ell_2$ regularized classifiers that minimize a convex loss. This formula was first obtained by the heuristic replica method of statistical physics. Secondly, focussing on commonly used loss functions and optimizing the $\ell_2$ regularization strength, we observe that while ridge regression performance is poor, logistic and hinge regression are surprisingly able to approach the Bayes-optimal generalization error extremely closely. As $\alpha \to \infty$ they lead to Bayes-optimal rates, a fact that does not follow from predictions of margin-based generalization error bounds. Third, we design an optimal loss and regularizer that provably leads to Bayes-optimal generalization error.


Deep Learning Superpixel Semantic Segmentation with Transparent Initialization and Sparse Encoder

arXiv.org Artificial Intelligence

Even though deep learning greatly improves the performance of semantic segmentation, its success mainly lies in object central areas but without accurate edges. As superpixel is a popular and effective auxiliary to preserve object edges, in this paper, we jointly learn semantic segmentation with trainable superpixels. We achieve it by adding fully-connected layers with transparent initialization and an efficient logit consistency with a sparse encoder. Specifically, the proposed transparent initialization reserves the effects of learned parameters from pretrained networks, one for semantic segmentation and the other for superpixel, by a linear data recovery. This avoids a significant loss increase by using the pretrained networks, which otherwise can be caused by an inappropriate parameter initialization on the added layers. Meanwhile, consistent assignments to all pixels in each superpixel can be guaranteed by the logit consistency with a sparse encoder. This sparse encoder with sparse matrix operations substantially improves the training efficiency by reducing the large computational complexity arising from indexing pixels by superpixels. We demonstrate the effectiveness of our proposal by transparent initialization and sparse encoder on semantic segmentation on PASCAL VOC 2012 dataset with enhanced labeling on the object edges. Moreover, the proposed transparent initialization can also be used to jointly finetune multiple or a deeper pretrained network on other tasks.


Linguistic Profiling of a Neural Language Model

arXiv.org Artificial Intelligence

In this paper we investigate the linguistic knowledge learned by a Neural Language Model (NLM) before and after a fine-tuning process and how this knowledge affects its predictions during several classification problems. We use a wide set of probing tasks, each of which corresponds to a distinct sentence-level feature extracted from different levels of linguistic annotation. We show that BERT is able to encode a wide range of linguistic characteristics, but it tends to lose this information when trained on specific downstream tasks. We also find that BERT's capacity to encode different kind of linguistic properties has a positive influence on its predictions: the more it stores readable linguistic information of a sentence, the higher will be its capacity of predicting the expected label assigned to that sentence.


Neural Networks Without Matrix Math

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The challenge of speeding up AI systems typically means adding more processing elements and pruning the algorithms, but those approaches aren't the only path forward. Almost all commercial machine learning applications depend on artificial neural networks, which are trained using large datasets with a back-propagation algorithm. This result is compared to the known "correct" answer, and the difference between the two is used to adjust the weights applied to the network nodes. The process repeats for as many training examples as needed to (hopefully) converge to a stable set of weights that gives acceptable accuracy. This standard algorithm requires two distinct computational paths -- a forward "inference" path to analyze the data, and a backward "gradient descent" path to correct node weights.