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The following page has been changed by KenKrugler: http://wiki.apache.org/nutch/FixingOpicScoring ------------------------------------------------------------------------------ 1. Each page also has a "historical cash value" that represents the cash that's flowed through the page. Initially this starts out as 0.0. 1. The score of a page is represented by the sum of the historical and current cash values. 1. There is one special, virtual root page that has bidirectional links with every other page in the entire web graph. - a. When a crawl is initially started, the root page has a cash value of 1.0, and this is then distributed (as 1/n) to the n injected pages. ''(What happens when more pages are injected?)'' + a. When a crawl is initially started, the root page has a cash value of 1.0, and this is then distributed (as 1/n) to the n injected pages. When more pages are injected, it's not clear what happens, but I imagine that some of the cash that has accumulated in the root page is distributed to the injected pages, thus keeping the total "energy" of the system constant. a. Whenever a page is being processed, the root page can receive some of the page's current cash, due to the implicit link from every page to the root page. 1. To handle recrawling, every page also has the last time it was processed. In addition, there's a fixed "time window" that's used to calculate the historical cash value of a page. For the Xyleme crawler, this was set at 3 months, but it seems to be heavily dependent on the rate of re-crawling (average time between page refetches). ''We could use a value derived from fetchInterval.'' 1. When a page is being processed, its historical cash value is calculated from the page's current cash value and the previous historical cash value. The historical cash value is estimated via interpolation to come up with an "expected" historical cash value, that is close to what you'd get if every page was re-fetched and processed at the same, regular interval. Details are below. ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Nutch-cvs mailing list Nutch-cvs@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/nutch-cvs
