Abstract: The present invention provides a selection method of array length of observation system, comprising: step S101: obtaining a seismic response equation for any point on ground based on wavefield propagation theory; step S102: determining at least one selection criterion of an optimum array length considering different factors according to the seismic response equation; step S103: obtaining the array lengths considering the different factors respectively according to the at least one selection criterion of the optimum array length; and step S104: integrating the array lengths considering the different factors and determining that the optimum array length is ?{square root over (2)} times the depth of the destination layer. Compared with conventional array length calculation method the demonstration method of array length as proposed in the present invention has the advantages of higher accuracy and applicability for destination layers.

Abstract: A system may determine a plurality of candidate regions in a web page, each candidate region comprising one or more page elements at neighboring positions in the web page. The system may extract, for each of the plurality of candidate regions, extraction values corresponding to a plurality of visual features in the candidate regions, the visual features being perceptible to human eyes, and the extraction values derived from attribute values respectively defined by the web page for the visual features. The system may select, from the plurality of candidate regions, a target region that satisfies an extraction criteria based on the extraction values corresponding to the visual features. The system may extract content information of the target region.

Abstract: A system may determine a plurality of candidate regions in a web page, each candidate region comprising one or more page elements at neighboring positions in the web page. The system may extract, for each of the plurality of candidate regions, extraction values corresponding to a plurality of visual features in the candidate regions, the visual features being perceptible to human eyes, and the extraction values derived from attribute values respectively defined by the web page for the visual features. The system may select, from the plurality of candidate regions, a target region that satisfies an extraction criteria based on the extraction values corresponding to the visual features. The system may extract content information of the target region.