Statistical Learning
[FREE] Machine Learning Fundamentals [Python]
Udemy is the biggest website in the world that offer courses in many categories, all the skills that you would be looking for are offered in Udemy, including languages, design, marketing and a lot of other categories, so when you ever want to buy a courses and pay for a new skills, Udemy would be the best forum for you. You can find payment courses, 100 free courses and coupons also, more than 12 categories are offered, and that what makes sure you will find the domain and the skill you are looking for. Our duty is to search for 100 off courses and free coupons. This course is designed to understand basic Concept of Machine Learning. Anyone can opt for this course.
Detect Malicious JavaScript Code Using Machine Learning
In this article, we will consider approaches to detect obfuscated JavaScript code snippets using machine learning. Most websites use JavaScript (JS) code to make dynamic content; thus, JS code becomes a valuable attack vector against browsers, browser plug-ins, email clients, and other JS applications. Among common JS-based attacks are drive-by-download, cross-site scripting (XSS), cross-site request forgery (XSRF), malvertising/malicious advertising, and others. Most of the malicious JS codes are obfuscated in order to hide what they are doing and to avoid being detected by signature-based security systems. In other words, the obfuscation technique is a sequence of confusing code transformations to compromise its understandability, but at the same time to save its functionality.
On Convergence of Gradient Descent Ascent: A Tight Local Analysis
Li, Haochuan, Farnia, Farzan, Das, Subhro, Jadbabaie, Ali
Gradient Descent Ascent (GDA) methods are the mainstream algorithms for minimax optimization in generative adversarial networks (GANs). Convergence properties of GDA have drawn significant interest in the recent literature. Specifically, for $\min_{\mathbf{x}} \max_{\mathbf{y}} f(\mathbf{x};\mathbf{y})$ where $f$ is strongly-concave in $\mathbf{y}$ and possibly nonconvex in $\mathbf{x}$, (Lin et al., 2020) proved the convergence of GDA with a stepsize ratio $\eta_{\mathbf{y}}/\eta_{\mathbf{x}}=\Theta(\kappa^2)$ where $\eta_{\mathbf{x}}$ and $\eta_{\mathbf{y}}$ are the stepsizes for $\mathbf{x}$ and $\mathbf{y}$ and $\kappa$ is the condition number for $\mathbf{y}$. While this stepsize ratio suggests a slow training of the min player, practical GAN algorithms typically adopt similar stepsizes for both variables, indicating a wide gap between theoretical and empirical results. In this paper, we aim to bridge this gap by analyzing the \emph{local convergence} of general \emph{nonconvex-nonconcave} minimax problems. We demonstrate that a stepsize ratio of $\Theta(\kappa)$ is necessary and sufficient for local convergence of GDA to a Stackelberg Equilibrium, where $\kappa$ is the local condition number for $\mathbf{y}$. We prove a nearly tight convergence rate with a matching lower bound. We further extend the convergence guarantees to stochastic GDA and extra-gradient methods (EG). Finally, we conduct several numerical experiments to support our theoretical findings.
Equilibrium Aggregation: Encoding Sets via Optimization
Bartunov, Sergey, Fuchs, Fabian B., Lillicrap, Timothy
Processing sets or other unordered, potentially variable-sized inputs in neural networks is usually handled by aggregating a number of input tensors into a single representation. While a number of aggregation methods already exist from simple sum pooling to multi-head attention, they are limited in their representational power both from theoretical and empirical perspectives. On the search of a principally more powerful aggregation strategy, we propose an optimization-based method called Equilibrium Aggregation. We show that many existing aggregation methods can be recovered as special cases of Equilibrium Aggregation and that it is provably more efficient in some important cases. Equilibrium Aggregation can be used as a drop-in replacement in many existing architectures and applications. We validate its efficiency on three different tasks: median estimation, class counting, and molecular property prediction. In all experiments, Equilibrium Aggregation achieves higher performance than the other aggregation techniques we test.
Mathematical Foundations of Graph-Based Bayesian Semi-Supervised Learning
Trillos, Nicolas García, Sanz-Alonso, Daniel, Yang, Ruiyi
In recent decades, science and engineering have been revolutionized by a momentous growth in the amount of available data. However, despite the unprecedented ease with which data are now collected and stored, labeling data by supplementing each feature with an informative tag remains to be challenging. Illustrative tasks where the labeling process requires expert knowledge or is tedious and time-consuming include labeling X-rays with a diagnosis, protein sequences with a protein type, texts by their topic, tweets by their sentiment, or videos by their genre. In these and numerous other examples, only a few features may be manually labeled due to cost and time constraints. How can we best propagate label information from a small number of expensive labeled features to a vast number of unlabeled ones? This is the question addressed by semi-supervised learning (SSL). This article overviews recent foundational developments on graph-based Bayesian SSL, a probabilistic framework for label propagation using similarities between features. SSL is an active research area and a thorough review of the extant literature is beyond the scope of this article. Our focus will be on topics drawn from our own research that illustrate the wide range of mathematical tools and ideas that underlie the rigorous study of the statistical accuracy and computational efficiency of graph-based Bayesian SSL.
Linear Machine Learning Algorithms: An Overview - KDnuggets
Linear machine learning algorithms assume a linear relationship between the features and the target variable. In this article, we'll discuss several linear algorithms and their concepts. Here's a glimpse into what you can expect to learn: You can use linear algorithms for classification and regression problems. Let's start by looking at different algorithms and what problems they solve. Linear regression is arguably one of the oldest and most popular algorithms.
8 Ways You Can 'Level Up' Your Machine Learning Projects
Need to classify data or predict outcomes? Are you struggling with your machine learning (Machine Learning) project? There are various techniques that can improve the situation. Some of the eight methods discussed below will dramatically accelerate the Machine Learning process, and others will not only accelerate the process, but will also help you build better models. Not all of these techniques will be suitable for a particular project.
PhilaeX: Explaining the Failure and Success of AI Models in Malware Detection
Lu, Zhi, Thing, Vrizlynn L. L.
The explanation to an AI model's prediction used to support decision making in cyber security, is of critical importance. It is especially so when the model's incorrect prediction can lead to severe damages or even losses to lives and critical assets. However, most existing AI models lack the ability to provide explanations on their prediction results, despite their strong performance in most scenarios. In this work, we propose a novel explainable AI method, called PhilaeX, that provides the heuristic means to identify the optimized subset of features to form the complete explanations of AI models' predictions. It identifies the features that lead to the model's borderline prediction, and those with positive individual contributions are extracted. The feature attributions are then quantified through the optimization of a Ridge regression model. We verify the explanation fidelity through two experiments. First, we assess our method's capability in correctly identifying the activated features in the adversarial samples of Android malwares, through the features attribution values from PhilaeX. Second, the deduction and augmentation tests, are used to assess the fidelity of the explanations. The results show that PhilaeX is able to explain different types of classifiers correctly, with higher fidelity explanations, compared to the state-of-the-arts methods such as LIME and SHAP.
Using Hashtags to Analyze Purpose and Technology Application of Open-Source Project Related to COVID-19
COVID-19 has had a profound impact on the lives of all human beings. Emerging technologies have made significant contributions to the fight against the pandemic. An extensive review of the application of technology will help facilitate future research and technology development to provide better solutions for future pandemics. In contrast to the extensive surveys of academic communities that have already been conducted, this study explores the IT community of practice. Using GitHub as the study target, we analyzed the main functionalities of the projects submitted during the pandemic. This study examines trends in projects with different functionalities and the relationship between functionalities and technologies. The study results show an imbalance in the number of projects with varying functionalities in the GitHub community, i.e., applications account for more than half of the projects. In contrast, other data analysis and AI projects account for a smaller share. This differs significantly from the survey of the academic community, where the findings focus more on cutting-edge technologies while projects in the community of practice use more mature technologies. The spontaneous behavior of developers may lack organization and make it challenging to target needs.
Local manifold learning and its link to domain-based physics knowledge
Zdybał, Kamila, D'Alessio, Giuseppe, Attili, Antonio, Coussement, Axel, Sutherland, James C., Parente, Alessandro
In many reacting flow systems, the thermo-chemical state-space is known or assumed to evolve close to a low-dimensional manifold (LDM). Various approaches are available to obtain those manifolds and subsequently express the original high-dimensional space with fewer parameterizing variables. Principal component analysis (PCA) is one of the dimensionality reduction methods that can be used to obtain LDMs. PCA does not make prior assumptions about the parameterizing variables and retrieves them empirically from the training data. In this paper, we show that PCA applied in local clusters of data (local PCA) is capable of detecting the intrinsic parameterization of the thermo-chemical state-space. We first demonstrate that utilizing three common combustion models of varying complexity: the Burke-Schumann model, the chemical equilibrium model and the homogeneous reactor. Parameterization of these models is known a priori which allows for benchmarking with the local PCA approach. We further extend the application of local PCA to a more challenging case of a turbulent non-premixed $n$-heptane/air jet flame for which the parameterization is no longer obvious. Our results suggest that meaningful parameterization can be obtained also for more complex datasets. We show that local PCA finds variables that can be linked to local stoichiometry, reaction progress and soot formation processes.