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 Support Vector Machines


Utilizing Network Properties to Detect Erroneous Inputs

arXiv.org Artificial Intelligence

Neural networks are vulnerable to a wide range of erroneous inputs such as adversarial, corrupted, out-of-distribution, and misclassified examples. In this work, we train a linear SVM classifier to detect these four types of erroneous data using hidden and softmax feature vectors of pre-trained neural networks. Our results indicate that these faulty data types generally exhibit linearly separable activation properties from correct examples, giving us the ability to reject bad inputs with no extra training or overhead. We experimentally validate our findings across a diverse range of datasets, domains, pre-trained models, and adversarial attacks.


Machine Learning Detects Multiplicity of the First Stars in Stellar Archaeology Data - IOPscience

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In unveiling the nature of the first stars, the main astronomical clue is the elemental compositions of the second generation of stars, observed as extremely metal-poor (EMP) stars, in the Milky Way. However, no observational constraint was available on their multiplicity, which is crucial for understanding early phases of galaxy formation. We develop a new data-driven method to classify observed EMP stars into mono- or multi-enriched stars with support vector machines. We also use our own nucleosynthesis yields of core-collapse supernovae with mixing fallback that can explain many of the observed EMP stars. Our method predicts, for the first time, that 31.8%


Extracting Physical Rehabilitation Exercise Information from Clinical Notes: a Comparison of Rule-Based and Machine Learning Natural Language Processing Techniques

arXiv.org Artificial Intelligence

However, physical therapy procedures are typically described in unstructured clinical notes, meaning that simple data extraction methods such as database queries cannot be applied to obtain sufficient information. Additionally, the language used to describe these procedures can differ between clinicians, cites, and times. A more advanced natural language processing (NLP) algorithm is required to extract this information from clinical notes, but such a method has not yet been developed for this application. In this paper we devise and compare several approaches to extracting information about therapeutic procedures for physical rehabilitation, both for the purpose of emulating a manual annotation process using named entity recognition (NER) and categorizing descriptions of therapeutic procedures using multi label sequence classification. Using a set of manually annotated notes as a gold standard reference, we evaluated the performance of a rule-based algorithm using the MedTagger software, and several machine learning approaches such as logistic regression (LR) and support vector machines (SVM). Methods Data Collection We identified a cohort of patients diagnosed with stroke between January 1st, 2016 and December 31st, 2016 at UPMC. For these patients, we extracted clinical encounter notes created between January 1st, 2016 and December 31st, 2018 from the institutional data warehouse. The study was approved by the University of Pittsburgh's Institutional Review Board (IRB #21040204).


A Single-Step Multiclass SVM based on Quantum Annealing for Remote Sensing Data Classification

arXiv.org Artificial Intelligence

In recent years, the development of quantum annealers has enabled experimental demonstrations and has increased research interest in applications of quantum annealing, such as in quantum machine learning and in particular for the popular quantum SVM. Several versions of the quantum SVM have been proposed, and quantum annealing has been shown to be effective in them. Extensions to multiclass problems have also been made, which consist of an ensemble of multiple binary classifiers. This work proposes a novel quantum SVM formulation for direct multiclass classification based on quantum annealing, called Quantum Multiclass SVM (QMSVM). The multiclass classification problem is formulated as a single Quadratic Unconstrained Binary Optimization (QUBO) problem solved with quantum annealing. The main objective of this work is to evaluate the feasibility, accuracy, and time performance of this approach. Experiments have been performed on the D-Wave Advantage quantum annealer for a classification problem on remote sensing data. The results indicate that, despite the memory demands of the quantum annealer, QMSVM can achieve accuracy that is comparable to standard SVM methods and, more importantly, it scales much more efficiently with the number of training examples, resulting in nearly constant time. This work shows an approach for bringing together classical and quantum computation, solving practical problems in remote sensing with current hardware.


An ADMM approach for multi-response regression with overlapping groups and interaction effects

arXiv.org Machine Learning

The constraints ensure that the interaction term can be nonzero only if the corresponding main term is nonzero. Even though the idea is still young, it has been applied in different areas, for example to multinomial logistic regression (Asenso et al., 2022b), Cox's proportional hazards model (Du and Tibshirani, 2018) and support vector machines (Asenso et al., 2022a). However, in all the above studies, the block-wise coordinate descent procedure was used in solving the problem which includes overlapping groups. The algorithm involves multiple "if" statements and a generalized gradient at the final stage. This implies that extending the model to a multi-response case would require rigorous computations like the case of Li et al. 2015, which might be difficult to handle. In this paper, we introduce the alternating direction method of multipliers (ADMM) to handle this problem and extend the results from the single response model to a multi-response problem. We provide a publicly available software package MAD-MMplasso (Asenso and Zucknick, 2022) implemented in R. We present a brief review on the ADMM algorithm in what follows.


Physics-informed neural nets. Introduction:

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Physics-Informed Neural Networks (PINNs) are a powerful tool for simulating complex physical systems. Unlike traditional machine learning models, PINNs can effectively utilize limited data by incorporating the underlying physics of the studied system. In scientific and engineering applications, acquiring large labeled datasets can be difficult due to the high cost and limited experimental or simulated data availability. Traditional machine learning models, such as decision trees or support vector machines, require large amounts of labeled data for effective training. However, PINNs can leverage the governing laws and constraints of the studied problem to achieve accurate results with minimal training data.


Enhancing COVID-19 Severity Analysis through Ensemble Methods

arXiv.org Artificial Intelligence

Computed Tomography (CT) scans provide a detailed image of the lungs, allowing clinicians to observe the extent of damage caused by COVID-19. The CT severity score (CTSS) based scoring method is used to identify the extent of lung involvement observed on a CT scan. This paper presents a domain knowledge-based pipeline for extracting regions of infection in COVID-19 patients using a combination of image-processing algorithms and a pre-trained UNET model. The severity of the infection is then classified into different categories using an ensemble of three machine-learning models: Extreme Gradient Boosting, Extremely Randomized Trees, and Support Vector Machine. The proposed system was evaluated on a validation dataset in the AI-Enabled Medical Image Analysis Workshop and COVID-19 Diagnosis Competition (AI-MIA-COV19D) and achieved a macro F1 score of 64%. These results demonstrate the potential of combining domain knowledge with machine learning techniques for accurate COVID-19 diagnosis using CT scans. The implementation of the proposed system for severity analysis is available at \textit{https://github.com/aanandt/Enhancing-COVID-19-Severity-Analysis-through-Ensemble-Methods.git }


Machine Learning and AI: Support Vector Machines in Python

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Support Vector Machines (SVM) are one of the most powerful machine learning models around, and this topic has been one that students have requested ever since I started making courses. These days, everyone seems to be talking about deep learning, but in fact there was a time when support vector machines were seen as superior to neural networks. One of the things you'll learn about in this course is that a support vector machine actually is a neural network, and they essentially look identical if you were to draw a diagram. The toughest obstacle to overcome when you're learning about support vector machines is that they are very theoretical. This theory very easily scares a lot of people away, and it might feel like learning about support vector machines is beyond your ability.


Tollywood Emotions: Annotation of Valence-Arousal in Telugu Song Lyrics

arXiv.org Artificial Intelligence

Emotion recognition from a given music track has heavily relied on acoustic features, social tags, and metadata but is seldom focused on lyrics. There are no datasets of Indian language songs that contain both valence and arousal manual ratings of lyrics. We present a new manually annotated dataset of Telugu songs' lyrics collected from Spotify with valence and arousal annotated on a discrete scale. A fairly high inter-annotator agreement was observed for both valence and arousal. Subsequently, we create two music emotion recognition models by using two classification techniques to identify valence, arousal and respective emotion quadrant from lyrics. Support vector machine (SVM) with term frequency-inverse document frequency (TF-IDF) features and fine-tuning the pre-trained XLMRoBERTa (XLM-R) model were used for valence, arousal and quadrant classification tasks. Fine-tuned XLMRoBERTa performs better than the SVM by improving macro-averaged F1-scores of 54.69%, 67.61%, 34.13% to 77.90%, 80.71% and 58.33% for valence, arousal and quadrant classifications, respectively, on 10-fold cross-validation. In addition, we compare our lyrics annotations with Spotify's annotations of valence and energy (same as arousal), which are based on entire music tracks. The implications of our findings are discussed. Finally, we make the dataset publicly available with lyrics, annotations and Spotify IDs.


High-Dimensional Penalized Bernstein Support Vector Machines

arXiv.org Artificial Intelligence

The support vector machines (SVM) is a powerful classifier used for binary classification to improve the prediction accuracy. However, the non-differentiability of the SVM hinge loss function can lead to computational difficulties in high dimensional settings. To overcome this problem, we rely on Bernstein polynomial and propose a new smoothed version of the SVM hinge loss called the Bernstein support vector machine (BernSVM), which is suitable for the high dimension $p >> n$ regime. As the BernSVM objective loss function is of the class $C^2$, we propose two efficient algorithms for computing the solution of the penalized BernSVM. The first algorithm is based on coordinate descent with maximization-majorization (MM) principle and the second one is IRLS-type algorithm (iterative re-weighted least squares). Under standard assumptions, we derive a cone condition and a restricted strong convexity to establish an upper bound for the weighted Lasso BernSVM estimator. Using a local linear approximation, we extend the latter result to penalized BernSVM with non convex penalties SCAD and MCP. Our bound holds with high probability and achieves a rate of order $\sqrt{s\log(p)/n}$, where $s$ is the number of active features. Simulation studies are considered to illustrate the prediction accuracy of BernSVM to its competitors and also to compare the performance of the two algorithms in terms of computational timing and error estimation. The use of the proposed method is illustrated through analysis of three large-scale real data examples.