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 Statistical Learning


Multi-way Graph Signal Processing on Tensors: Integrative analysis of irregular geometries

arXiv.org Machine Learning

Graph signal processing (GSP) is an important methodology for studying data residing on irregular structures. As acquired data is increasingly taking the form of multi-way tensors, new signal processing tools are needed to maximally utilize the multi-way structure within the data. In this paper, we review modern signal processing frameworks generalizing GSP to multi-way data, starting from graph signals coupled to familiar regular axes such as time in sensor networks, and then extending to general graphs across all tensor modes. This widely applicable paradigm motivates reformulating and improving upon classical problems and approaches to creatively address the challenges in tensor-based data. We synthesize common themes arising from current efforts to combine GSP with tensor analysis and highlight future directions in extending GSP to the multi-way paradigm. Over the past decade, graph signal processing (GSP) [1] has laid the foundation for generalizing classical Fourier theory as defined on a regular grid, such as time, to handle signals on irregular structures, such as networks. GSP, however, is currently limited to single-way analysis: graph signals are processed independently of one another, thus ignoring the geometry between multiple graph signals. In the coming decade, generalizing GSP to handle multi-way data, represented by multidimensional arrays or tensors, with graphs underlying each axis of the data will be essential for modern signal processing. To introduce the concept of way, consider a network of N sensors each measuring a signal sampled at T time points. On the one hand, classic signal processing treats these signals as a collection of N independent 1D timeseries ignoring the relation structure of the graph. T. Both are single-way perspectives that ignore the underlying geometry of the other way (also referred to as mode).


Minibatch vs Local SGD for Heterogeneous Distributed Learning

arXiv.org Machine Learning

We analyze Local SGD (aka parallel or federated SGD) and Minibatch SGD in the heterogeneous distributed setting, where each machine has access to stochastic gradient estimates for a different, machine-specific, convex objective; the goal is to optimize w.r.t. the average objective; and machines can only communicate intermittently. We argue that, (i) Minibatch SGD (even without acceleration) dominates all existing analysis of Local SGD in this setting, (ii) accelerated Minibatch SGD is optimal when the heterogeneity is high, and (iii) present the first upper bound for Local SGD that improves over Minibatch SGD in a non-homogeneous regime.


Case ntroduction to Machine Learning with Case Study in Python

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We're team of Machine Learning experts, AI developers working together to advance the state of the art in artificial intelligence. You will be hearing from us when new courses are released, answering Q&A and many more. We are here to help you stay on the cutting edge of Data Science and Technology.


Deep Learning Prerequisites: Linear Regression in Python

#artificialintelligence

Online Courses Udemy - Deep Learning Prerequisites: Linear Regression in Python, Data science: Learn linear regression from scratch and build your own working program in Python for data analysis. Bestseller Created by Lazy Programmer Inc English [Auto], Spanish [Auto] Students also bought Recommender Systems and Deep Learning in Python Unsupervised Deep Learning in Python Machine Learning and AI: Support Vector Machines in Python Data Science: Natural Language Processing (NLP) in Python Natural Language Processing with Deep Learning in Python Ensemble Machine Learning in Python: Random Forest, AdaBoost Preview this course GET COUPON CODE Description This course teaches you about one popular technique used in machine learning, data science and statistics: linear regression. We cover the theory from the ground up: derivation of the solution, and applications to real-world problems. We show you how one might code their own linear regression module in Python. Linear regression is the simplest machine learning model you can learn, yet there is so much depth that you'll be returning to it for years to come.


tSNE simplified

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Guys, to tell you the truth when I heard the name tSNE and the full form being t-distributed stochastic neighborhood embedding, I was scared. Gradually, I could find my way through the papers, various blogs, and realized it is not so ominous as the name suggests. I just thought I will try to share the intuitions that I gathered. Let me put it down in a question, answer format like it came to my mind. Less number of attributes are simpler to manage.


Overfitting and Underfitting in Machine Learning

#artificialintelligence

In this article, we are going to indulge in two of the most discussed about and important concepts in machine learning which is related to the performance of a model. How do we know a model is performing better? Which model should we choose? For eg: I applied linear regression and decision tree algorithm on the train dataset of a classification problem. From above table, we can see that delta value from decision tree (5%) delta value from linear regression (20%), hence Decision would be perform best in this scenario. Note: Lower the delta value, higher the performance of the model.


Fully Bayesian Analysis of the Relevance Vector Machine Classification for Imbalanced Data

arXiv.org Machine Learning

Relevance Vector Machine (RVM) is a supervised learning algorithm extended from Support Vector Machine (SVM) based on the Bayesian sparsity model. Compared with the regression problem, RVM classification is difficult to be conducted because there is no closed-form solution for the weight parameter posterior. Original RVM classification algorithm used Newton's method in optimization to obtain the mode of weight parameter posterior then approximated it by a Gaussian distribution in Laplace's method. It would work but just applied the frequency methods in a Bayesian framework. This paper proposes a Generic Bayesian approach for the RVM classification. We conjecture that our algorithm achieves convergent estimates of the quantities of interest compared with the nonconvergent estimates of the original RVM classification algorithm. Furthermore, a Fully Bayesian approach with the hierarchical hyperprior structure for RVM classification is proposed, which improves the classification performance, especially in the imbalanced data problem. By the numeric studies, our proposed algorithms obtain high classification accuracy rates. The Fully Bayesian hierarchical hyperprior method outperforms the Generic one for the imbalanced data classification.


Bounded Fuzzy Possibilistic Method of Critical Objects Processing in Machine Learning

arXiv.org Artificial Intelligence

Unsatisfying accuracy of learning methods is mostly caused by omitting the influence of important parameters such as membership assignments, type of data objects, and distance or similarity functions. The proposed method, called Bounded Fuzzy Possibilistic Method (BFPM) addresses different issues that previous clustering or classification methods have not sufficiently considered in their membership assignments. In fuzzy methods, the object's memberships should sum to 1. Hence, any data object may obtain full membership in at most one cluster or class. Possibilistic methods relax this condition, but the method can be satisfied with the results even if just an arbitrary object obtains the membership from just one cluster, which prevents the objects' movement analysis. Whereas, BFPM differs from previous fuzzy and possibilistic approaches by removing these restrictions. Furthermore, BFPM provides the flexible search space for objects' movement analysis. Data objects are also considered as fundamental keys in learning methods, and knowing the exact type of objects results in providing a suitable environment for learning algorithms. The Thesis introduces a new type of object, called critical, as well as categorizing data objects into two different categories: structural-based and behavioural-based. Critical objects are considered as causes of miss-classification and miss-assignment in learning procedures. The Thesis also proposes new methodologies to study the behaviour of critical objects with the aim of evaluating objects' movements (mutation) from one cluster or class to another. The Thesis also introduces a new type of feature, called dominant, that is considered as one of the causes of miss-classification and miss-assignments. Then the Thesis proposes new sets of similarity functions, called Weighted Feature Distance (WFD) and Prioritized Weighted Feature Distance (PWFD).


Beyond the Worst-Case Analysis of Algorithms (Introduction)

arXiv.org Machine Learning

One of the primary goals of the mathematical analysis of algorithms is to provide guidance about which algorithm is the "best" for solving a given computational problem. Worst-case analysis summarizes the performance profile of an algorithm by its worst performance on any input of a given size, implicitly advocating for the algorithm with the best-possible worst-case performance. Strong worst-case guarantees are the holy grail of algorithm design, providing an application-agnostic certification of an algorithm's robustly good performance. However, for many fundamental problems and performance measures, such guarantees are impossible and a more nuanced analysis approach is called for. This chapter surveys several alternatives to worst-case analysis that are discussed in detail later in the book.


Dimensionality Reduction for $k$-means Clustering

arXiv.org Machine Learning

Along with modern developments and the necessity of large high-dimensional datasets, which due to their nature result in overfitting of many machine learning algorithms, it is crucial that one reduces the complexity of the algorithms involving these datasets. The authors of [BDM09] are of the first to address the issue of clustering in such datasets with provably accurate approximation results, by proposing a simple pre-processing step to the " k-means" clustering algorithm; also known as Lloyd's method [Llo82] -- probably the most widely used and popular clustering algorithm.