@CONFERENCE\{IMM2008-05486,
    author       = "R. I. Jonsson and T. Bj{\o}rnvinsson and M. Blanke and N. K. Poulsen and S. H{\o}jsgaard and L. Munksgaard",
    title        = "Oestrus Detection in Dairy Cows Using Likelihood Ratio Tests",
    year         = "2008",
    booktitle    = "{IFAC} world congress, Seoul.",
    volume       = "",
    series       = "",
    editor       = "",
    publisher    = "",
    organization = "",
    address      = "",
    url          = "http://www2.compute.dtu.dk/pubdb/pubs/5486-full.html",
    abstract     = "This paper addresses detection of oestrus in dairy cows using methods from statistical change detection. Measuring cows' activity by a necklace attached sensor, statistical properties of the activity measure were investigated. Using data sets from about 100 individuals, diurnal activity variations were identified for the ensemble and for the individual cows. A diurnal filter was adapted to remove the average daily variation of the individual. Change detection algorithms were designed for the actual probability densities, which were Rayleigh distributed but had individual parameters for each cow. A generalized likelihood ratio algorithm was derived for the compensated activity signal and detection  algorithm was tested on 2323 days of activity, which contained in total 42 oestruses on 12 cows. The application of statistical change detection methods is a new approach for detecting oestrus in dairy cows and the results are shown to outperform earlier approaches in  respect to false alarm and missed detection statistics."
}