7,851 research outputs found
Improving spam filtering by combining Naive Bayes with simple k-nearest neighbor searches
Using naive Bayes for email classification has become very popular within the
last few months. They are quite easy to implement and very efficient. In this
paper we want to present empirical results of email classification using a
combination of naive Bayes and k-nearest neighbor searches. Using this
technique we show that the accuracy of a Bayes filter can be improved slightly
for a high number of features and significantly for a small number of features
A Graph-Based Semi-Supervised k Nearest-Neighbor Method for Nonlinear Manifold Distributed Data Classification
Nearest Neighbors (NN) is one of the most widely used supervised
learning algorithms to classify Gaussian distributed data, but it does not
achieve good results when it is applied to nonlinear manifold distributed data,
especially when a very limited amount of labeled samples are available. In this
paper, we propose a new graph-based NN algorithm which can effectively
handle both Gaussian distributed data and nonlinear manifold distributed data.
To achieve this goal, we first propose a constrained Tired Random Walk (TRW) by
constructing an -level nearest-neighbor strengthened tree over the graph,
and then compute a TRW matrix for similarity measurement purposes. After this,
the nearest neighbors are identified according to the TRW matrix and the class
label of a query point is determined by the sum of all the TRW weights of its
nearest neighbors. To deal with online situations, we also propose a new
algorithm to handle sequential samples based a local neighborhood
reconstruction. Comparison experiments are conducted on both synthetic data
sets and real-world data sets to demonstrate the validity of the proposed new
NN algorithm and its improvements to other version of NN algorithms.
Given the widespread appearance of manifold structures in real-world problems
and the popularity of the traditional NN algorithm, the proposed manifold
version NN shows promising potential for classifying manifold-distributed
data.Comment: 32 pages, 12 figures, 7 table
Stacking classifiers for anti-spam filtering of e-mail
We evaluate empirically a scheme for combining classifiers, known as stacked
generalization, in the context of anti-spam filtering, a novel cost-sensitive
application of text categorization. Unsolicited commercial e-mail, or "spam",
floods mailboxes, causing frustration, wasting bandwidth, and exposing minors
to unsuitable content. Using a public corpus, we show that stacking can improve
the efficiency of automatically induced anti-spam filters, and that such
filters can be used in real-life applications
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