Gabriel Wachman

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Spam is a key problem in electronic communication, including large-scale email systems and the growing number of blogs. Content-based filtering is one reliable method of combating this threat in its various forms, but some academic researchers and industrial practitioners disagree on how best to filter spam. The former have advocated the use of Support(More)
The paper presents a kernel for learning from ordered hypergraphs, a formalization that captures relational data as used in Inductive Logic Programming (ILP). The kernel generalizes previous approaches to graph kernels in calculating similarity based on walks in the hypergraph. Experiments on challenging chemical datasets demonstrate that the kernel(More)
A large number of variants of the Perceptron algorithm have been proposed and partially evaluated in recent work. One type of algorithm aims for noise tolerance by replacing the last hypothesis of the perceptron with another hypothesis or a vote among hypotheses. Another type simply adds a margin term to the perceptron in order to increase robustness and(More)
We present a method for applying machine learning algorithms to the automatic classification of astronomy star surveys using time series of star brightness. Currently such classification requires a large amount of domain expert time. We show that a combination of phase invariant similarity and explicit features extracted from the time series provide domain(More)
Contemporary spammers commonly seek to defeat statistical spam filters through the use of word obfuscation. Such methods include character level substitutions, repetitions, and insertions to reduce the effectiveness of word-based features. We present an efficient method for combating obfuscation through the use of inexact string matching kernels, which were(More)
Cognitive networking mechanisms promise to greatly improve network performance over non~cognitive mechanisms, by making more efficient nse of bandwidth, spectrum, and power. However, these mechanisms must be designed v,'ilh cyber security in mind in order to rem~lin efficient in lhe presence of subverted, adversarial participants. In t.his paper, we(More)
Advances in genotyping assays have resulted in commercially available, costeffective whole-genome analyses. Once relegated to major genomics centers, genotyping capabilities are now spreading to smaller academic and industrial labs worldwide. With vast numbers of microbial sequences published in online databases, there is increasing interest in not only(More)
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