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 Support Vector Machines


Data as voters: instance selection using approval-based multi-winner voting

arXiv.org Artificial Intelligence

Instance selection (or prototype selection) [García et al.(2015)] is a preprocessing task in machine learning (or data mining) that aims at selecting a subset of the data instances composing the training set that a machine learning algorithm will use. There are two main reasons to perform this task: efficiency and cleaning. Reducing the size of the training set reduces the computational cost of running the machine learning algorithm, especially in the case of instance-based classifiers like KNN (see the Preliminaries section for a description of KNN classifiers). Furthermore, we may be interested in removing noisy instances from the training set: instances due to errors or other causes can induce mistakes in the machine learning algorithm.


Quantum Kernel Alignment with Stochastic Gradient Descent

arXiv.org Artificial Intelligence

Quantum support vector machines have the potential to achieve a quantum speedup for solving certain machine learning problems. The key challenge for doing so is finding good quantum kernels for a given data set -- a task called kernel alignment. In this paper we study this problem using the Pegasos algorithm, which is an algorithm that uses stochastic gradient descent to solve the support vector machine optimization problem. We extend Pegasos to the quantum case and and demonstrate its effectiveness for kernel alignment. Unlike previous work which performs kernel alignment by training a QSVM within an outer optimization loop, we show that using Pegasos it is possible to simultaneously train the support vector machine and align the kernel. Our experiments show that this approach is capable of aligning quantum feature maps with high accuracy, and outperforms existing quantum kernel alignment techniques. Specifically, we demonstrate that Pegasos is particularly effective for non-stationary data, which is an important challenge in real-world applications.


Snacks: a fast large-scale kernel SVM solver

arXiv.org Artificial Intelligence

Kernel methods provide a powerful framework for non parametric learning. They are based on kernel functions and allow learning in a rich functional space while applying linear statistical learning tools, such as Ridge Regression or Support Vector Machines. However, standard kernel methods suffer from a quadratic time and memory complexity in the number of data points and thus have limited applications in large-scale learning. In this paper, we propose Snacks, a new large-scale solver for Kernel Support Vector Machines. Specifically, Snacks relies on a Nystr\"om approximation of the kernel matrix and an accelerated variant of the stochastic subgradient method. We demonstrate formally through a detailed empirical evaluation, that it competes with other SVM solvers on a variety of benchmark datasets.


Comparative Study of MPPT and Parameter Estimation of PV cells

arXiv.org Artificial Intelligence

Solar energy has been developed as a better alternative to fossil fuels in the past few years. It is a renewable and infinite source of energy which does not have a bad impact on the environment. It is also cheap and easily accessible, making it a better alternative for both personal and commercial purposes. Solar Arrays are made when PV modules used in solar panels are connected together. Energy is produced when sunlight falls on Solar Panels which can be used instead of Fossil fuel's produced energy. For execution of a PV system under different situations, estimating the parameters in a PV model plays an important role because it enables us to optimise the design and performance of the system which leads to increased energy production and improved performance. If a PV system is not performing as expected, then identification of parameters of the PV model helps identify the root cause of the problem. This could be due to factors such as shading, module mismatch, or degradation over time. By accurately estimating the parameters, we can determine the best method to improve its performance.


The Evolution Of AI: Transforming The World One Algorithm At A Time

#artificialintelligence

The journey of AI started in the 1950s with the pioneering work of Alan Turing, who proposed the Turing Test to determine if a machine could mimic human intelligence. In the 1960s, AI research gained momentum with the development of the first AI programming language, LISP, by John McCarthy. Early AI systems focused on symbolic reasoning and rule-based systems, which led to the development of expert systems in the 1970s and 1980s. The 1990s witnessed a shift in focus towards machine learning and data-driven approaches, driven by the increased availability of digital data and advancements in computing power. This period saw the rise of neural networks and the development of support vector machines, which allowed AI systems to learn from data, leading to better performance and adaptability.


D-SVM over Networked Systems with Non-Ideal Linking Conditions

arXiv.org Artificial Intelligence

This paper considers distributed optimization algorithms, with application in binary classification via distributed support-vector-machines (D-SVM) over multi-agent networks subject to some link nonlinearities. The agents solve a consensus-constraint distributed optimization cooperatively via continuous-time dynamics, while the links are subject to strongly sign-preserving odd nonlinear conditions. Logarithmic quantization and clipping (saturation) are two examples of such nonlinearities. In contrast to existing literature that mostly considers ideal links and perfect information exchange over linear channels, we show how general sector-bounded models affect the convergence to the optimizer (i.e., the SVM classifier) over dynamic balanced directed networks. In general, any odd sector-bounded nonlinear mapping can be applied to our dynamics. The main challenge is to show that the proposed system dynamics always have one zero eigenvalue (associated with the consensus) and the other eigenvalues all have negative real parts. This is done by recalling arguments from matrix perturbation theory. Then, the solution is shown to converge to the agreement state under certain conditions. For example, the gradient tracking (GT) step size is tighter than the linear case by factors related to the upper/lower sector bounds. To the best of our knowledge, no existing work in distributed optimization and learning literature considers non-ideal link conditions.


Towards Understanding How Data Augmentation Works with Imbalanced Data

arXiv.org Artificial Intelligence

Data augmentation forms the cornerstone of many modern machine learning training pipelines; yet, the mechanisms by which it works are not clearly understood. Much of the research on data augmentation (DA) has focused on improving existing techniques, examining its regularization effects in the context of neural network over-fitting, or investigating its impact on features. Here, we undertake a holistic examination of the effect of DA on three different classifiers, convolutional neural networks, support vector machines, and logistic regression models, which are commonly used in supervised classification of imbalanced data. We support our examination with testing on three image and five tabular datasets. Our research indicates that DA, when applied to imbalanced data, produces substantial changes in model weights, support vectors and feature selection; even though it may only yield relatively modest changes to global metrics, such as balanced accuracy or F1 measure. We hypothesize that DA works by facilitating variances in data, so that machine learning models can associate changes in the data with labels. By diversifying the range of feature amplitudes that a model must recognize to predict a label, DA improves a model's capacity to generalize when learning with imbalanced data.


A Hybrid Physics Machine Learning Approach for Macroscopic Traffic State Estimation

arXiv.org Artificial Intelligence

Full-field traffic state information (i.e., flow, speed, and density) is critical for the successful operation of Intelligent Transportation Systems (ITS) on freeways. However, incomplete traffic information tends to be directly collected from traffic detectors that are insufficiently installed in most areas, which is a major obstacle to the popularization of ITS. To tackle this issue, this paper introduces an innovative traffic state estimation (TSE) framework that hybrid regression machine learning techniques (e.g., artificial neural network (ANN), random forest (RF), and support vector machine (SVM)) with a traffic physics model (e.g., second-order macroscopic traffic flow model) using limited information from traffic sensors as inputs to construct accurate and full-field estimated traffic state for freeway systems. To examine the effectiveness of the proposed TSE framework, this paper conducted empirical studies on a real-world data set collected from a stretch of I-15 freeway in Salt Lake City, Utah. Experimental results show that the proposed method has been proved to estimate full-field traffic information accurately. Hence, the proposed method could provide accurate and full-field traffic information, thus providing the basis for the popularization of ITS.


Machine Learning in Three Steps: How to Efficiently Learn It

#artificialintelligence

I have observed two extreme approaches when it comes to aspiring data scientists attempting to learn machine learning algorithms. The first approach involves learning all the intricacies of the algorithms and implementing them from scratch to gain true mastery. The second approach, on the other hand, assumes that the computer will "learn" on its own, rendering the need for the individual to learn the algorithms unnecessary. This leads some to only rely on tools such as the package lazypredict. It is realistic to take an approach between the two extremes when learning machine learning algorithms. However, the question remains, where to start? In this article, I will categorize machine learning algorithms into three categories and provide my humble opinion on what to begin with and what can be skipped. Starting out in machine learning can be overwhelming due to the multitude of available algorithms. Linear regression, support vector machines (SVM), gradient descent, gradient boosting, decision trees, LASSO, ridge, grid search, and many more are some of the algorithms that come to mind when posed with the question.


How Sentiment Classification works part1(Machine Learning)

#artificialintelligence

Abstract: With the rapid growth of the use of social media websites, obtaining the users' feedback automatically became a crucial task to evaluate their tendencies and behaviors online. Despite this great availability of information, and the increasing number of Arabic users only few research has managed to treat Arabic dialects. The purpose of this paper is to study the opinion and emotion expressed in real Moroccan texts precisely in the YouTube comments using some well-known and commonly used methods for sentiment analysis. In this paper, we present our work of Moroccan dialect comments classification using Machine Learning (ML) models and based on our collected and manually annotated YouTube Moroccan dialect dataset. By employing many text preprocessing and data representation techniques we aim to compare our classification results utilizing the most commonly used supervised classifiers: k-nearest neighbors (KNN), Support Vector Machine (SVM), Naive Bayes (NB), and deep learning (DL) classifiers such as Convolutional Neural Network (CNN) and Long Short-Term Memory (LTSM).