Biedermann Technologies (Germany)

In this paper an approach towards databased fault diagnosis of linear electromagnetic actuators is presented. Time and time-frequency-domain methods were applied to extract fault related features from current and voltage measurements. The resulting features were transformed to enhance class separability using either Principal Component Analysis (PCA) or Optimal Transformation. Feature selection and dimensionality reduction was performed employing a modified Fisher-ratio. Fault detection was carried out using a Support-Vector-Machine classifier trained with randomly selected data subsets. Results showed, that not only the used feature sets (time-domain/time-frequency-domain) are crucial for fault detection and classification, but also feature pre-processing. PCA transformed time-domain features allow fault detection and classification without misclassification, relying on current and voltage measurements making two sensors necessary to generate the data. Optimal transformed time-frequency-domain features allow a misclassification free result as well, but as they are calculated from current measurements only, a dedicated voltage sensor is not necessary. Using those features is a promising alternative even for detecting purely supply voltage related faults.

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Abstract. Title of the paper: Genetic analysis of the population of Hinterwald cattle Since 1994 the Hinterwald population is devided into one of dairy cows and one of suckling cows. The bulls are available to both subpopulations. By means of herdbook records of the year of 2002 there were gained 79 bulls, 698 dairy cows and 517 suckling cows. Considering five generations of ancestors the subpopulations have been investigated with regard to genetic contribution, generation intervals, and circumstances of relationship and inbreeding. The average percentage of Hinterwald blood in the current population amounts to 97 %. The genetic portions of other breeds are low and mostly originating from Vorderwald cattle. The mean generation interval (parents–current animals) is about 5 years. Between the sires and current animals it is shorter (about 4 years) than between the dams and the current animals (about 7 years). The average coefficient of relationship among the bulls is the highest (3.7 %) compared to the dairy cows (2.2 %) and the suckling cows (0.9 %). The mean degree of inbreeding is 1.2 up to 1.3 %, and 37 % of the bulls, 57 % of the dairy cows and 74 % of the suckling cows are not inbred. The increase of inbreeding is rather low and doesn’t surmount 0.7 % in all subpopulations. Therefore it can be assumed that the Hinterwald cattle at present is not subjected to any danger of inbreeding.