Goto

Collaborating Authors

 Nearest Neighbor Methods


Recognizing Snacks using SimpleCV

#artificialintelligence

This article aims to provide the basic knowledge of how to recognize snacks by using Python and SimpleCV. Readers will gain practical programming knowledge via experimentation with the Python scripts included in the Snack Classifier open source project. To illustrate with a snacks recognition app, the Snack Watcher watches any snacks present on the snack table. For Snack Watcher to determine if there was an interesting event, it needs to process the image into a set of image "Blobs". For each "Blob", Snack Watcher compares the "Blob" with it's previous state to determine if the "Blob" was added, removed or stationary.


K Nearest Neighbors Application - Practical Machine Learning Tutorial with Python p.14

#artificialintelligence

In the last part we introduced Classification, which is a supervised form of machine learning, and explained the K Nearest Neighbors algorithm intuition. In this tutorial, we're actually going to apply a simple example of the algorithm using Scikit-Learn, and then in the subsquent tutorials we'll build our own algorithm to learn more about how it works under the hood. To exemplify classification, we're going to use a Breast Cancer Dataset, which is a dataset donated to the University of California, Irvine (UCI) collection from the University of Wisconsin-Madison. UCI has a large Machine Learning Repository.


Clustering idea for very large datasets

@machinelearnbot

Let's say you have to cluster 10 million points, for instance keywords. So, in short, you can perform k-NN (k-nearest neighbors) clustering or some other types of clustering, which typically is O(n 2) or worse, from a computational complexity point of view. Has anyone ever used a clustering method based on sampling? The idea is to start by sampling 1% (or less) of the 100,000,000 entries, and perform clustering on these pairs of keywords, to create a "seed" or "baseline" cluster structure. The next step is to browse sequentially your 10,000,000 keywords, and for each keyword, find the closest cluster from the baseline cluster structure.


DIY Recommendation Engines for Mom and Pop Ecommerce Shops

#artificialintelligence

Of course we have all heard about machine learning and recommendation engines in big business ecommerce. For quite some time, massive ecommerce businesses like Netflix, Amazon, and Ebay have been leveraging the power of data science to improve customer service and boost sales. Where once this technology was cost-prohibitive to all but the major players, recently things have changed. Thanks to multi-channel ecommerce platforms like Shopify, and the developers who are building custom machine learning add-ons, now mom and pop online businesses get the chance to infuse their operations with the power of data science. In this article I introduce how machine learning algorithms work to produce recommendation systems for small business ecommerce.


Flattening the Density Gradient for Eliminating Spatial Centrality to Reduce Hubness

AAAI Conferences

Spatial centrality, whereby samples closer to the center of a dataset tend to be closer to all other samples, is regarded as one source of hubness. Hubness is well known to degrade k-nearest-neighbor (k-NN) classification. Spatial centrality can be removed by centering, i.e., shifting the origin to the global center of the dataset, in cases where inner product similarity is used. However, when Euclidean distance is used, centering has no effect on spatial centrality because the distance between the samples is the same before and after centering. As described in this paper, we propose a solution for the hubness problem when Euclidean distance is considered. We provide a theoretical explanation to demonstrate how the solution eliminates spatial centrality and reduces hubness. We then present some discussion of the reason the proposed solution works, from a viewpoint of density gradient, which is regarded as the origin of spatial centrality and hubness. We demonstrate that the solution corresponds to flattening the density gradient. Using real-world datasets, we demonstrate that the proposed method improves k-NN classification performance and outperforms an existing hub-reduction method.


Variable dimension data? โ€ข /r/MachineLearning

@machinelearnbot

You could do K-nearest neighbor's interpolation to give the empty 0 values a "guess" to how they would look like to the nearest neighbors. How well this would work is really just based on the properties of the data. If dimension k can be predicted by some association with a dimension j, and this relationship with k and j is fairly strong throughout the data, then it's worth trying. If it's all over the place, this hack won't help at all, perhaps it would even make very unreliable predictions.


Study Identifies Key Factors Associated With Dementia Pathogenesis

#artificialintelligence

Recent research has identified independent predictors of dementia to include age at diagnosis, transient ischemic attack and stroke status, and years of education, with vascular factors playing a greater role in disease pathogenesis than previously thought. The findings were presented at the 2016 annual meeting of the American Academy of Neurology (AAN). In the abstract, the researchers wrote that dementia encompasses a broad set of neurologic diseases, producing progressive declines in memory and/or thinking faculties, sometimes alongside personality and emotional disturbances. "Worldwide, approximately 35.6 million people have dementia, and this number is only expected to grow due to an aging population," they wrote. "Unfortunately, it is exceedingly difficult to predict who will develop dementia, let alone what type. This makes it difficult to mobilize various preventive strategies supported by mounting evidence."


Learning Vector Quantization for Machine Learning - Machine Learning Mastery

#artificialintelligence

A downside of K-Nearest Neighbors is that you need to hang on to your entire training dataset. The Learning Vector Quantization algorithm (or LVQ for short) is an artificial neural network algorithm that lets you choose how many training instances to hang onto and learns exactly what those instances should look like. In this post you will discover the Learning Vector Quantization algorithm. This post was written for developers and assumes no background in statistics or mathematics. The post focuses on how the algorithm works and how to use it for predictive modeling problems.


K-Nearest Neighbors for Machine Learning - Machine Learning Mastery

#artificialintelligence

In this post you will discover the k-Nearest Neighbors (KNN) algorithm for classification and regression. After reading this post you will know. This post was written for developers and assumes no background in statistics or mathematics. The focus is on how the algorithm works and how to use it for predictive modeling problems. If you have any questions, leave a comment and I will do my best to answer.


Feature extraction using Latent Dirichlet Allocation and Neural Networks: A case study on movie synopses

arXiv.org Machine Learning

Feature extraction has gained increasing attention in the field of machine learning, as in order to detect patterns, extract information, or predict future observations from big data, the urge of informative features is crucial. The process of extracting features is highly linked to dimensionality reduction as it implies the transformation of the data from a sparse high-dimensional space, to higher level meaningful abstractions. This dissertation employs Neural Networks for distributed paragraph representations, and Latent Dirichlet Allocation to capture higher level features of paragraph vectors. Although Neural Networks for distributed paragraph representations are considered the state of the art for extracting paragraph vectors, we show that a quick topic analysis model such as Latent Dirichlet Allocation can provide meaningful features too. We evaluate the two methods on the CMU Movie Summary Corpus, a collection of 25,203 movie plot summaries extracted from Wikipedia. Finally, for both approaches, we use K-Nearest Neighbors to discover similar movies, and plot the projected representations using T-Distributed Stochastic Neighbor Embedding to depict the context similarities. These similarities, expressed as movie distances, can be used for movies recommendation. The recommended movies of this approach are compared with the recommended movies from IMDB, which use a collaborative filtering recommendation approach, to show that our two models could constitute either an alternative or a supplementary recommendation approach.