Nearest Neighbor Methods


Machine Learning Building KNN Model Eduonix

#artificialintelligence

This Video will help you build a KNN model, we will work on a cancel cell Data set, In pattern recognition, the k-nearest neighbors algorithm is a non-parametric method used for classification and regression. In both cases, the input consists of the k closest training examples in the feature space Get flat 15% OFF on the above complete course with other projects here with certification - http://bit.ly/2TwTcxh Get 10% flat off on the Below full E-Degree with certification - (APPLY COPOUN - YTDEG) The Best courses to do with Eduonix with are - 1.Learn Machine Learning By Building Projects - http://bit.ly/2MxMSSl 2.The Complete Web Development Course - Build 15 Projects - http://bit.ly/32Ah9oW 3.The Full Stack Web Development - http://bit.ly/2MZDBRV 4.Projects In Laravel: Learn Laravel Building 10 Projects - http://bit.ly/2MAiHtH 5.Mathematical Foundation For Machine Learning and AI - http://bit.ly/2N23Eb1 Get 15% flat off on the below courses with certification - (APPLY COPOUN - YTEDU) Python Programming An Expert Guide on Python - http://bit.ly/2Bp75Dj Get 10% flat off on the Below full E-Degree with certification - (APPLY COPOUN - YTDEG) AI & ML E-degree- http://bit.ly/2mEUCYC


Machine Learning & Tensorflow - Google Cloud Approach

#artificialintelligence

Students who have at least high school knowledge in math and who want to start learning Machine Learning. Any intermediate level people who know the basics of machine learning, including the classical algorithms like linear regression or logistic regression, but who want to learn more about it and explore all the different fields of Machine Learning. Any people who are not that comfortable with coding but who are interested in Machine Learning and want to apply it easily on datasets. Anyone willing to learn machine learning on Google cloud platform. Any students in college who want to start a career in Data Science. Any data analysts who want to level up in Machine Learning.


Learning a Distance Metric from a Network

Neural Information Processing Systems

Many real-world networks are described by both connectivity information and features for every node. To better model and understand these networks, we present structure preserving metric learning (SPML), an algorithm for learning a Mahalanobis distance metric from a network such that the learned distances are tied to the inherent connectivity structure of the network. Like the graph embedding algorithm structure preserving embedding, SPML learns a metric which is structure preserving, meaning a connectivity algorithm such as k-nearest neighbors will yield the correct connectivity when applied using the distances from the learned metric. We show a variety of synthetic and real-world experiments where SPML predicts link patterns from node features more accurately than standard techniques. We further demonstrate a method for optimizing SPML based on stochastic gradient descent which removes the running-time dependency on the size of the network and allows the method to easily scale to networks of thousands of nodes and millions of edges.


Efficient anomaly detection using bipartite k-NN graphs

Neural Information Processing Systems

Learning minimum volume sets of an underlying nominal distribution is a very effective approach to anomaly detection. Several approaches to learning minimum volume sets have been proposed in the literature, including the K-point nearest neighbor graph (K-kNNG) algorithm based on the geometric entropy minimization (GEM) principle [4]. The K-kNNG detector, while possessing several desirable characteristics, suffers from high computation complexity, and in [4] a simpler heuristic approximation, the leave-one-out kNNG (L1O-kNNG) was proposed. In this paper, we propose a novel bipartite k-nearest neighbor graph (BP-kNNG) anomaly detection scheme for estimating minimum volume sets. Our bipartite estimator retains all the desirable theoretical properties of the K-kNNG, while being computationally simpler than the K-kNNG and the surrogate L1O-kNNG detectors.


Phase transition in the family of p-resistances

Neural Information Processing Systems

We study the family of p-resistances on graphs for p 1. We prove that for any fixed graph, for p 1, the p-resistance coincides with the shortest path distance, for p 2 it coincides with the standard resistance distance, and for p it converges to the inverse of the minimal s-t-cut in the graph. Secondly, we consider the special case of random geometric graphs (such as k-nearest neighbor graphs) when the number n of vertices in the graph tends to infinity. We prove that an interesting phase-transition takes place. There exist two critical thresholds p * and p ** such that if p p *, then the p-resistance depends on meaningful global properties of the graph, whereas if p p **, it only depends on trivial local quantities and does not convey any useful information. We can explicitly compute the critical values: p * 1 1/(d-1) and p ** 1 1/(d-2) where d is the dimension of the underlying space (we believe that the fact that there is a small gap between p * and p ** is an artifact of our proofs.


Diffusion Decision Making for Adaptive k-Nearest Neighbor Classification

Neural Information Processing Systems

We show that conventional k-nearest neighbor classification can be viewed as a special problem of the diffusion decision model in the asymptotic situation. Applying the optimal strategy associated with the diffusion decision model, an adaptive rule is developed for determining appropriate values of k in k-nearest neighbor classification. Making use of the sequential probability ratio test (SPRT) and Bayesian analysis, we propose five different criteria for adaptively acquiring nearest neighbors. Experiments with both synthetic and real datasets demonstrate the effectivness of our classification criteria. Papers published at the Neural Information Processing Systems Conference.


Discriminative Metric Learning by Neighborhood Gerrymandering

Neural Information Processing Systems

We formulate the problem of metric learning for k nearest neighbor classification as a large margin structured prediction problem, with a latent variable representing the choice of neighbors and the task loss directly corresponding to classification error. We describe an efficient algorithm for exact loss augmented inference,and a fast gradient descent algorithm for learning in this model. The objective drives the metric to establish neighborhood boundaries that benefit the true class labels for the training points. Our approach, reminiscent of gerrymandering (redrawing of political boundaries to provide advantage to certain parties), is more direct in its handling of optimizing classification accuracy than those previously proposed. In experiments on a variety of data sets our method is shown to achieve excellent results compared to current state of the art in metric learning.


Heterogeneous-Neighborhood-based Multi-Task Local Learning Algorithms

Neural Information Processing Systems

All the existing multi-task local learning methods are defined on homogeneous neighborhood which consists of all data points from only one task. In this paper, different from existing methods, we propose local learning methods for multi-task classification and regression problems based on heterogeneous neighborhood which is defined on data points from all tasks. Specifically, we extend the k-nearest-neighbor classifier by formulating the decision function for each data point as a weighted voting among the neighbors from all tasks where the weights are task-specific. By defining a regularizer to enforce the task-specific weight matrix to approach a symmetric one, a regularized objective function is proposed and an efficient coordinate descent method is developed to solve it. For regression problems, we extend the kernel regression to multi-task setting in a similar way to the classification case.


Rapid Distance-Based Outlier Detection via Sampling

Neural Information Processing Systems

Distance-based approaches to outlier detection are popular in data mining, as they do not require to model the underlying probability distribution, which is particularly challenging for high-dimensional data. We present an empirical comparison of various approaches to distance-based outlier detection across a large number of datasets. We report the surprising observation that a simple, sampling-based scheme outperforms state-of-the-art techniques in terms of both efficiency and effectiveness. To better understand this phenomenon, we provide a theoretical analysis why the sampling-based approach outperforms alternative methods based on k-nearest neighbor search. Papers published at the Neural Information Processing Systems Conference.


Density estimation from unweighted k-nearest neighbor graphs: a roadmap

Neural Information Processing Systems

Consider an unweighted k-nearest neighbor graph on n points that have been sampled i.i.d. We prove how one can estimate the density p just from the unweighted adjacency matrix of the graph, without knowing the points themselves or their distance or similarity scores. The key insights are that local differences in link numbers can be used to estimate some local function of p, and that integrating this function along shortest paths leads to an estimate of the underlying density. Papers published at the Neural Information Processing Systems Conference.