Support Vector Machines
To deep, or not to deep, that is the question!
As in other fields of artificial intelligence and prior to the emergence of Deep Learning, especially deep neural networks, artificial vision research was focused on a traditional Machine Learning approach. The traditional machine learning approach relies on developers massaging the data to extract the most salient or significant aspects from the data they are dealing with; that is, time sequences of frames, or videos. In this case, both scientific research and application development have been centered around identifying the most significant image elements that would allow, for example, facial and body recognition of the people who appear in the images, tracking them from one frame to another, or classifying the vehicles that move through a given area. After extracting this meaningful data, statistical methods are then employed to transform the representation into a so-called "understanding" of the real visual environment by using clustering, support-vector machines (SVMs), and filtering algorithms (linear, non-linear, regression), among others. This means that the merits of any given application lie in how well researchers and developers are able to source and generate data from the raw processed frames and transform it into useful structured data.
Spectroscopy and Chemometrics News Weekly #11, 2020
How to Develop Near-Infrared Spectroscopy Calibrations in the 21st Century? Chemometrics Analytische Chemie LINK Simplify the process of training machine learning models for NIR spectra data with applied near-infrared spectroscopy (NIRS) knowledge. LINK "An optimized non-invasive glucose sensing based on scattering and absorption separating using near-infrared spectroscopy" LINK "Identification of waxy cassava genotypes using fourier‐transform near‐infrared spectroscopy" LINK "Kernel functions embedded in support vector machine learning models for rapid water pollution assessment via near-infrared spectroscopy" LINK "Near-infrared-based Identification of Walnut Oil Authenticity" LINK "Detection of flaxseed oil multiple adulteration by near-infrared spectroscopy and nonlinear one class partial least squares discriminant analysis" LINK "Application research of sensor output digitization for compact near infrared IOT node" LINK "Refining Transfer Set in Calibration Transfer of Near ...
Key Phrase Classification in Complex Assignments
Complex assignments typically consist of open-ended questions with large and diverse content in the context of both classroom and online graduate programs. With the sheer scale of these programs comes a variety of problems in peer and expert feedback, including rogue reviews. As such with the hope of identifying important contents needed for the review, in this work we present a very first work on key phrase classification with a detailed empirical study on traditional and most recent language modeling approaches. From this study, we find that the task of classification of key phrases is ambiguous at a human level producing Cohen's kappa of 0.77 on a new data set. Both pretrained language models and simple TFIDF SVM classifiers produce similar results with a former producing average of 0.6 F1 higher than the latter. We finally derive practical advice from our extensive empirical and model interpretability results for those interested in key phrase classification from educational reports in the future.
Singular Value Decomposition of Operators on Reproducing Kernel Hilbert Spaces
Mollenhauer, Mattes, Schuster, Ingmar, Klus, Stefan, Schütte, Christof
Reproducing kernel Hilbert spaces (RKHSs) play an important role in many statistics and machine learning applications ranging from support vector machines to Gaussian processes and kernel embeddings of distributions. Operators acting on such spaces are, for instance, required to embed conditional probability distributions in order to implement the kernel Bayes rule and build sequential data models. It was recently shown that transfer operators such as the Perron-Frobenius or Koopman operator can also be approximated in a similar fashion using covariance and cross-covariance operators and that eigenfunctions of these operators can be obtained by solving associated matrix eigenvalue problems. The goal of this paper is to provide a solid functional analytic foundation for the eigenvalue decomposition of RKHS operators and to extend the approach to the singular value decomposition. The results are illustrated with simple guiding examples.
Why math is easy for AI but gardening is not: Moravec's paradox
Artificial intelligence (AI) systems, powered by massive data and sophisticated algorithms -- including but not limited to -- deep neural networks and statistical machine learning (ML)(support vector machines, clustering, random forest, etc.), are having profound and transformative impact on our daily lives as they make their way into everything from finance to healthcare, from retail to transportation. Netflix movie recommender, Amazon's product prediction, Facebook's uncanny ability to show what you may like, Google's assistant, DeepMind's AlphaGo, Stanford's AI beating human doctors. Machine learning is eating software. However, one of the common features of these powerful algorithms is that they utilize sophisticated mathematics to do their job -- to classify and segment an image, to arrive at the key decisions, to make a product recommendation, to model a complex phenomenon, or to extract and visualize a hidden pattern from a deluge of data. All of these mathematical processes are, quite simply, beyond the scope of a single human (or a team) to perform manually (even on a computer) or inside their head.
TF-IDFC-RF: A Novel Supervised Term Weighting Scheme
Carvalho, Flavio, Guedes, Gustavo Paiva
Sentiment Analysis is a branch of Affective Computing usually considered a binary classification task. In this line of reasoning, Sentiment Analysis can be applied in several contexts to classify the attitude expressed in text samples, for example, movie reviews, sarcasm, among others. A common approach to represent text samples is the use of the Vector Space Model to compute numerical feature vectors consisting of the weight of terms. The most popular term weighting scheme is TF-IDF (Term Frequency - Inverse Document Frequency). It is an Unsupervised Weighting Scheme (UWS) since it does not consider the class information in the weighting of terms. Apart from that, there are Supervised Weighting Schemes (SWS), which consider the class information on term weighting calculation. Several SWS have been recently proposed, demonstrating better results than TF-IDF. In this scenario, this work presents a comparative study on different term weighting schemes and proposes a novel supervised term weighting scheme, named as TF-IDFC-RF (Term Frequency - Inverse Document Frequency in Class - Relevance Frequency). The effectiveness of TF-IDFC-RF is validated with SVM (Support Vector Machine) and NB (Naive Bayes) classifiers on four commonly used Sentiment Analysis datasets. TF-IDFC-RF outperforms all other weighting schemes and achieves F1 results of more than 99.9% on all datasets with SVM classifier.
Top 5 Data Science Algorithms that you must know!
Right now, we utilize different data science algorithms to solve the task needing to be done. There are many algorithms out there, so it tends to be quite overpowering for beginners. Today, we will quickly present the top 5 mainstream Machine Learning algorithms so you can get settled with the energizing universe of Data Science! Linear Regression is likely the most famous ML algorithm. It finds a line that best fits a dissipated data points on a graph.
Machine Learning-based Approach for Depression Detection in Twitter Using Content and Activity Features
AlSagri, Hatoon S., Ykhlef, Mourad
Social media channels, such as Facebook, Twitter, and Instagram, have altered our world forever. People are now increasingly connected than ever and reveal a sort of digital persona. Although social media certainly has several remarkable features, the demerits are undeniable as well. Recent studies have indicated a correlation between high usage of social media sites and increased depression. The present study aims to exploit machine learning techniques for detecting a probable depressed Twitter user based on both, his/her network behavior and tweets. For this purpose, we trained and tested classifiers to distinguish whether a user is depressed or not using features extracted from his/ her activities in the network and tweets. The results showed that the more features are used, the higher are the accuracy and F-measure scores in detecting depressed users. This method is a data-driven, predictive approach for early detection of depression or other mental illnesses. This study's main contribution is the exploration part of the features and its impact on detecting the depression level.
Security of Distributed Machine Learning: A Game-Theoretic Approach to Design Secure DSVM
Distributed machine learning algorithms play a significant role in processing massive data sets over large networks. However, the increasing reliance on machine learning on information and communication technologies (ICTs) makes it inherently vulnerable to cyber threats. This work aims to develop secure distributed algorithms to protect the learning from data poisoning and network attacks. We establish a game-theoretic framework to capture the conflicting goals of a learner who uses distributed support vector machines (SVMs) and an attacker who is capable of modifying training data and labels. We develop a fully distributed and iterative algorithm to capture real-time reactions of the learner at each node to adversarial behaviors. The numerical results show that distributed SVM is prone to fail in different types of attacks, and their impact has a strong dependence on the network structure and attack capabilities.
A working likelihood approach to support vector regression with a data-driven insensitivity parameter
The insensitive parameter in support vector regression determines the set of support vectors that greatly impacts the prediction. A data-driven approach is proposed to determine an approximate value for this insensitive parameter by minimizing a generalized loss function originating from the likelihood principle. This data-driven support vector regression also statistically standardizes samples using the scale of noises. Nonlinear and linear numerical simulations with three types of noises ($\epsilon$-Laplacian distribution, normal distribution, and uniform distribution), and in addition, five real benchmark data sets, are used to test the capacity of the proposed method. Based on all of the simulations and the five case studies, the proposed support vector regression using a working likelihood, data-driven insensitive parameter is superior and has lower computational costs.