Although there are many reasons why medium voltage (MV) overhead lines with covered conductors (CCs) are used instead of aluminum-conductor steel-reinforced cables, the operation of CCs takes into account a difficult detection of faults, e.g., the contact of a tree branch with a CC. In this paper, we continue with the previous work on an electric voltage-based method enabling the detection of the CC faults; we introduce a new indicator of the faults based on the frequency of peaks in the signal of partial discharges. We mainly demonstrate the fault detection in a real MV distribution system, including a number of fault detectors; a fault is detected in 99.2% of occurrences within a long-term testing, although the cost of the detector is minimized in comparison with other similar fault detectors.
We describe an application of information extraction from company Web sites focusing on product offers. A statistical approach to text analysis is used in conjunction with different ways of image classification. Ontological knowledge is used to group the extracted items into structured objects. The results are stored in an RDF repository and made available for structured search.