]> 2026-04-04T17:12:55+02:00 Publications:Estimating p-Values for Deviation Detection 500 en <p>Deviation detection is important for self-monitoring systems. To perform deviation detection well requires methods that, given only "normal" data from a distribution of unknown parametric form, can produce a reliable statistic for rejecting the null hypothesis, i.e. evidence for devating data. One measure of the strength of this evidence based on the data is the p-value, but few deviation detection methods utilize p-value estimation. We compare three methods that can be used to produce p-values: one class support vector machine (OCSVM), conformal anomaly detection (CAD), and a simple "most central pattern" (MCP) algorithm. The SVM and the CAD method should be able to handle a distribution of any shape. The methods are evaluated on synthetic data sets to test and illustrate their strengths and weaknesses, and on data from a real life self-monitoring scenario with a city bus fleet in normal traffic. The OCSVM has a Gaussian kernel for the synthetic data and a Hellinger kernel for the empirical data. The MCP method uses the Mahalanobis metric for the synthetic data and the Hellinger metric for the empirical data. The CAD uses the same metrics as the MCP method and has a k-nearest neighbour (kNN) non-conformity measure for both sets. The conclusion is that all three methods give reasonable, and quite similar, results on the real life data set but that they have clear strengths and weaknesses on the synthetic data sets. The MCP algorithm is quick and accurate when the "normal" data distribution is unimodal and symmetric (with the chosen metric) but not otherwise. The OCSVM is a bit cumbersome to use to create (quantized) p-values but is accurate and reliable when the data distribution is multimodal and asymmetric. The CAD is also accurate for multimodal and asymmetric distributions. The experiment on the vehicle data illustrate how algorithms like these can be used in a self-monitoring system that uses a fleet of vehicles to conduct deviation detection without supervisi- n and without prior knowledge about what is being monitored.</p> SASO 2014 - Eighth IEEE International Conference on Self-Adaptive and Self-Organizing Systems, Imperial College, London, United Kingdom, September 8-12, 2014 http://dx.doi.org/10.1109/SASO.2014.22 http://hh.diva-portal.org/smash/record.jsf?searchId=1&pid=diva2:734143 109 Proceedings : 2014 IEEE Eighth International Conference on Self-Adaptive and Self-Organizing Systems SASO 2014 Conference Paper 100 Estimating p-Values for Deviation Detection 2014 2016-09-30T20:40:40Z 2457662.3615741 Estimating p-Values for Deviation Detection 500 0 plainlist list 1 [[:Publications:Estimating p-Values for Deviation Detection]] Estimating p-Values for Deviation Detection# QUERY371954db41db5dc293bb9f03f138a0c9 500 [2,"smw-datavalue-property-restricted-annotation-use","Publisher"] Estimating p-Values for Deviation Detection# ERR6c155b5d70b69ddb590b4f2e73389c2a 500 [2,"smw-datavalue-property-restricted-annotation-use","Author"] Estimating p-Values for Deviation Detection# ERRe24f17e090c98448f3de99d03182b7b6