Nearest Neighbor Methods
Universal Online Learning: an Optimistically Universal Learning Rule
We study the subject of universal online learning with non-i.i.d. processes for bounded losses. The notion of an universally consistent learning was defined by Hanneke in an effort to study learning theory under minimal assumptions, where the objective is to obtain low long-run average loss for any target function. We are interested in characterizing processes for which learning is possible and whether there exist learning rules guaranteed to be universally consistent given the only assumption that such learning is possible. The case of unbounded losses is very restrictive, since the learnable processes almost surely visit a finite number of points and as a result, simple memorization is optimistically universal. We focus on the bounded setting and give a complete characterization of the processes admitting strong and weak universal learning. We further show that k-nearest neighbor algorithm (kNN) is not optimistically universal and present a novel variant of 1NN which is optimistically universal for general input and value spaces in both strong and weak setting. This closes all COLT 2021 open problems posed by Hanneke on universal online learning.
Learning from One and Only One Shot
Yu, Haizi, Mineyev, Igor, Varshney, Lav R., Evans, James A.
Humans can generalize from only a few examples and from little pre-training on similar tasks. Yet, machine learning (ML) typically requires large data to learn or pre-learn to transfer. Inspired by nativism, we directly model basic human-innate priors in abstract visual tasks e.g., character/doodle recognition. This yields a white-box model that learns general-appearance similarity -- how any two images look in general -- by mimicking how humans naturally "distort" an object at first sight. Using simply the nearest-neighbor classifier on this similarity space, we achieve human-level character recognition using only 1--10 examples per class and nothing else (no pre-training). This differs from few-shot learning (FSL) using significant pre-training. On standard benchmarks MNIST/EMNIST and the Omniglot challenge, we outperform both neural-network-based and classical ML in the "tiny-data" regime, including FSL pre-trained on large data. Our model enables unsupervised learning too: by learning the non-Euclidean, general-appearance similarity space in a k-means style, we can generate human-intuitive archetypes as cluster ``centroids''.
Reasoning Through Memorization: Nearest Neighbor Knowledge Graph Embeddings
Zhang, Ningyu, Xie, Xin, Chen, Xiang, Deng, Shumin, Tan, Chuanqi, Huang, Fei, Cheng, Xu, Chen, Huajun
Previous knowledge graph embedding approaches usually map entities to representations and utilize score functions to predict the target entities, yet they struggle to reason rare or emerging unseen entities. In this paper, we propose kNN-KGE, a new knowledge graph embedding approach, by linearly interpolating its entity distribution with k-nearest neighbors. We compute the nearest neighbors based on the distance in the entity embedding space from the knowledge store. Our approach can allow rare or emerging entities to be memorized explicitly rather than implicitly in model parameters. Experimental results demonstrate that our approach can improve inductive and transductive link prediction results and yield better performance for low-resource settings with only a few triples, which might be easier to reason via explicit memory.
Universal Online Learning with Bounded Loss: Reduction to Binary Classification
Blanchard, Moรฏse, Cosson, Romain
We study universal consistency of non-i.i.d. processes in the context of online learning. A stochastic process is said to admit universal consistency if there exists a learner that achieves vanishing average loss for any measurable response function on this process. When the loss function is unbounded, Blanchard et al. showed that the only processes admitting strong universal consistency are those taking a finite number of values almost surely. However, when the loss function is bounded, the class of processes admitting strong universal consistency is much richer and its characterization could be dependent on the response setting (Hanneke). In this paper, we show that this class of processes is independent from the response setting thereby closing an open question (Hanneke, Open Problem 3). Specifically, we show that the class of processes that admit universal online learning is the same for binary classification as for multiclass classification with countable number of classes. Consequently, any output setting with bounded loss can be reduced to binary classification. Our reduction is constructive and practical. Indeed, we show that the nearest neighbor algorithm is transported by our construction. For binary classification on a process admitting strong universal learning, we prove that nearest neighbor successfully learns at least all finite unions of intervals.
Simple Explanation to Machine Learning Ensemble concept
I have been always a fan of using analogies and learning examples instead of complicated statistics and math functions in order to understand a concept in Machine learning. That's being said let's look at this situation. You just bought a new football club. Your new football club does not have any players and there are already 3 teams in the league. Team A has conceded 0 goals all seasons thus it is concluded that Team A has the best defense mechanism.
Supervised laser-speckle image sampling of skin tissue to detect very early stage of diabetes by its effects on skin subcellular properties
Orun, Ahmet, Critien, Luke Vella, Carter, Jennifer, Stacey, Martin
This paper investigates the effectiveness of an expert system based on K-nearest neighbours algorithm for laser speckle image sampling applied to the early detection of diabetes. With the latest developments in artificial intelligent guided laser speckle imaging technologies, it may be possible to optimise laser parameters, such as wavelength, energy level and image texture measures in association with a suitable AI technique to interact effectively with the subcellular properties of a skin tissue to detect early signs of diabetes. The new approach is potentially more effective than the classical skin glucose level observation because of its optimised combination of laser physics and AI techniques, and additionally, it allows non-expert individuals to perform more frequent skin tissue tests for an early detection of diabetes. Keywords: diabetes, automated diagnosis, laser-speckle image, skin subcellular properties, image analysis.
Local and Global Point Cloud Reconstruction for 3D Hand Pose Estimation
Yu, Ziwei, Yang, Linlin, Chen, Shicheng, Yao, Angela
The 3D shape and pose of the human hand are critical for augmented and virtual reality applications. To accommodate this form of human-computer interaction, an entire discipline of computer vision is devoted to estimating 3D hand shape and pose. Achieving accurate estimates is extremely challenging due to the hand's high degrees of articulation and self-occlusion. Earlier approaches attempted to combine representations from various viewpoints [7, 8, 9, 10], or transform 2.5D depth maps to 3D representations such as voxels [23, 25], point clouds [21], or meshes [34]. Since 3D voxel models are computationally more expensive than mesh and point cloud models, the latter two are preferable for estimating 3D hand shape and pose. Current RGB-based methods [2, 19, 46] prefer to estimate hand shape by mapping visual features to the parameters of a parametric model e.g.
Siamese Attribute-missing Graph Auto-encoder
Tu, Wenxuan, Zhou, Sihang, Liu, Yue, Liu, Xinwang
Graph representation learning (GRL) on attribute-missing graphs, which is a common yet challenging problem, has recently attracted considerable attention. We observe that existing literature: 1) isolates the learning of attribute and structure embedding thus fails to take full advantages of the two types of information; 2) imposes too strict distribution assumption on the latent space variables, leading to less discriminative feature representations. In this paper, based on the idea of introducing intimate information interaction between the two information sources, we propose our Siamese Attribute-missing Graph Auto-encoder (SAGA). Specifically, three strategies have been conducted. First, we entangle the attribute embedding and structure embedding by introducing a siamese network structure to share the parameters learned by both processes, which allows the network training to benefit from more abundant and diverse information. Second, we introduce a K-nearest neighbor (KNN) and structural constraint enhanced learning mechanism to improve the quality of latent features of the missing attributes by filtering unreliable connections. Third, we manually mask the connections on multiple adjacent matrices and force the structural information embedding sub-network to recover the true adjacent matrix, thus enforcing the resulting network to be able to selectively exploit more high-order discriminative features for data completion. Extensive experiments on six benchmark datasets demonstrate the superiority of our SAGA against the state-of-the-art methods.
Complete Machine Learning & Data Science with Python
Machine learning is constantly being applied to new industries. Learn Machine Learning with Hands-On Examples What is Machine Learning? Machine Learning Terminology What are Classification vs Regression? Evaluating Performance-Classification Error Metrics Evaluating Performance-Regression Error Metrics Cross Validation and Bias Variance Trade-Off Use matplotlib and seaborn for data visualizations Machine Learning with SciKit Learn Linear Regression Algorithm Logistic Regresion Algorithm K Nearest Neighbors Algorithm Decision Trees And Random Forest Algorithm Support Vector Machine Algorithm Unsupervised Learning K Means Clustering Algorithm Hierarchical Clustering Algorithm Principal Component Analysis (PCA) Recommender System Algorithm Python instructors on OAK Academy specialize in everything from software development to data analysis, and are known for their effective. Python is a general-purpose, object-oriented, high-level programming language. Python is a multi-paradigm language, which means that it supports many programming approaches. Along with procedural and functional programming styles Python is a widely used, general-purpose programming language, but it has some limitations. Because Python is an interpreted, dynamically typed language Python is a general programming language used widely across many industries and platforms. One common use of Python is scripting, which means automating tasks. Python is a popular language that is used across many industries and in many programming disciplines. DevOps engineers use Python to script website. Python has a simple syntax that makes it an excellent programming language for a beginner to learn. To learn Python on your own, you first must become familiar Machine learning describes systems that make predictions using a model trained on real-world data. Machine learning is being applied to virtually every field today. That includes medical diagnoses, facial recognition, weather forecasts, image processing.
MACHINE LEARNING WITH PYTHON: INTRODUCTION
This article is for current and aspiring machine learning practitioners looking to implement solutions to real-world machine learning problems. It is an introductory article suitable for beginners with no previous knowledge of machine learning or artificial intelligence (AI). This is the first article on my series "Machine Learning with Python". I will introduce the fundamental concepts of Machine Learning, its applications and how to set up our working environment as well as a hands on practices on a simple project. Machine learning is a type of artificial intelligence (AI) that provides computers with the ability to learn without being explicitly programmed.