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 Support Vector Machines


Classification with imperfect training labels

arXiv.org Machine Learning

We study the effect of imperfect training data labels on the performance of classification methods. In a general setting, where the probability that an observation in the training dataset is mislabelled may depend on both the feature vector and the true label, we bound the excess risk of an arbitrary classifier trained with imperfect labels in terms of its excess risk for predicting a noisy label. This reveals conditions under which a classifier trained with imperfect labels remains consistent for classifying uncorrupted test data points. Furthermore, under stronger conditions, we derive detailed asymptotic properties for the popular $k$-nearest neighbour ($k$nn), Support Vector Machine (SVM) and Linear Discriminant Analysis (LDA) classifiers. One consequence of these results is that the $k$nn and SVM classifiers are robust to imperfect training labels, in the sense that the rate of convergence of the excess risks of these classifiers remains unchanged; in fact, it even turns out that in some cases, imperfect labels may improve the performance of these methods. On the other hand, the LDA classifier is shown to be typically inconsistent in the presence of label noise unless the prior probabilities of each class are equal. Our theoretical results are supported by a simulation study.


Neural networks for stock price prediction

arXiv.org Machine Learning

Due to the extremely volatile nature of financial markets, it is commonly accepted that stock price prediction is a task full of challenge. However in order to make profits or understand the essence of equity market, numerous market participants or researchers try to forecast stock price using various statistical, econometric or even neural network models. In this work, we survey and compare the predictive power of five neural network models, namely, back propagation (BP) neural network, radial basis function (RBF) neural network, general regression neural network (GRNN), support vector machine regression (SVMR), least squares support vector machine regresssion (LS-SVMR). We apply the five models to make price prediction of three individual stocks, namely, Bank of China, Vanke A and Kweichou Moutai. Adopting mean square error and average absolute percentage error as criteria, we find BP neural network consistently and robustly outperforms the other four models.


Machine Learning Classification Algorithms using MATLAB

#artificialintelligence

This course is for you If you are being fascinated by the field of Machine Learning? This course is designed to cover one of the most interesting areas of machine learning called classification. I will take you step-by-step in this course and will first cover the basics of MATLAB. Following that we will look into the details of how to use different machine learning algorithms using MATLAB. Specifically, we will be looking at the MATLAB toolbox called statistic and machine learning toolbox.We will implement some of the most commonly used classification algorithms such as K-Nearest Neighbor, Naive Bayes, Discriminant Analysis, Decision Tress, Support Vector Machines, Error Correcting Ouput Codes and Ensembles. Following that we will be looking at how to cross validate these models and how to evaluate their performances.


Machine Learning Optimization Using Genetic Algorithm

@machinelearnbot

In this course, you will learn what hyperparameters are, what Genetic Algorithm is, and what hyperparameter optimization is. In this course, you will apply Genetic Algorithm to optimize the performance of Support Vector Machines and Multilayer Perceptron Neural Networks. Hyperparameter optimization will be done on two datasets, a regression dataset for the prediction of cooling and heating loads of buildings, and a classification dataset regarding the classification of emails into spam and non-spam. The SVM and MLP will be applied on the datasets without optimization and compare their results to after their optimization. By the end of this course, you will have learnt how to code Genetic Algorithm in Python and how to optimize your Machine Learning algorithms for maximal performance.


Face Recognition for Beginners โ€“ Towards Data Science

#artificialintelligence

Face Recognition is a recognition technique used to detect faces of individuals whose images saved in the data set. Despite the point that other methods of identification can be more accurate, face recognition has always remained a significant focus of research because of its non-meddling nature and because it is people's facile method of personal identification. Face recognition algorithms classified as geometry based or template based algorithms. The template-based methods can be constructed using statistical tools like SVM [Support Vector Machines], PCA [Principal Component Analysis], LDA [Linear Discriminant Analysis], Kernel methods or Trace Transforms. The geometric feature based methods analyse local facial features and their geometric relationship.


Function Estimation via Reconstruction

arXiv.org Machine Learning

This paper introduces an interpolation-based method, called the reconstruction approach, for function estimation in nonparametric models. Based on the fact that interpolation usually has negligible errors compared to statistical estimation, the reconstruction approach uses an interpolator to parameterize the unknown function with its values at finite knots, and then estimates these values by minimizing a regularized empirical risk function. Some popular methods including kernel ridge regression and kernel support vector machines can be viewed as its special cases. It is shown that, the reconstruction idea not only provides different angles to look into existing methods, but also produces new effective experimental design and estimation methods for nonparametric models.


GIS and Innovations in Machine Learning GIS Lounge

#artificialintelligence

Machine learning or artificial techniques has been rapidly transforming many areas related to GIS and spatial applications. One example is using web GIS with machine learning algorithms to predict or forecast the success of given potential hotel sites. This has been created into an application called Hotel Location Selection and Analyzing Toolset (HoLSAT). Techniques such as pursuit regression, artificial neural network, and support vector regression allow the tool to determine beneficial hotel locations based on a variety of criteria.[1] Determining where landslides might occur is also another potential application for machine learning techniques such as decision trees (DT) and adaptive neuro-fuzzy inference methods.


First-person reading activity recognition by deep learning with synthetically generated images

#artificialintelligence

With the development of wearable cameras, first-person activity recognition has been a popular topic in recent years [1]. There are many conventional approaches which tackle first-person activity recognition. Some of these approaches employ motion feature such as optical flow and also a classifier, e.g., LogitBoost and SVM (support vector machine)[2, 3]. In recent years, DCNN (deep convolutional neural network), the state-of-the-art model for visual recognition, has been proposed [4] and then applied to several tasks on first-person activity recognition. Although DCNN models provide remarkable results for image recognition, they require a large amount of labeled training samples.


A Beginner's Guide to Machine Learning (in Python)

@machinelearnbot

In this course, you will learn the basics of Machine Learning and Data Mining; almost everything you need to get started. You will understand what Big Data is and what Data Science and Data Analytics is. You will learn algorithms such as Linear Regression, Logistic Regression, Support Vector Machine, K-Nearest Neighbor, Decision Trees, and Neural Networks. You'll also understand how to combine algorithms into ensembles. Preprocessing data will be taught and you will understand how to clean your data, transform it, how to handle categorical features, and how to handle unbalanced data.


Wasserstein Coresets for Lipschitz Costs

arXiv.org Machine Learning

Sparsification is becoming more and more relevant with the proliferation of huge data sets. Coresets are a principled way to construct representative weighted subsets of a data set that have matching performance with the full data set for specific problems. However, coreset language neglects the nature of the underlying data distribution, which is often continuous. In this paper, we address this oversight by introducing a notion of measure coresets that generalizes coreset language to arbitrary probability measures. Our definition reveals a surprising connection to optimal transport theory which we leverage to design a coreset for problems with Lipschitz costs. We validate our construction on support vector machine (SVM) training, k-means clustering, k-median clustering, and linear regression and show that we are competitive with previous coreset constructions.