PDF Publication Title:
Text from PDF Page: 102
80 4 ⋅ random alpha pagerank Also, a person will always visit a page without clicking a link, and so we add another page to the total pages viewed. This adjustment fixes an important problem when the only observation of a person are page views with no clicks. The α is 0, which is incorrect. By assumption, everyone will click on a link at some point and the pseudo-counts adjust for these finite size results. Two aspects of the Beta fit are surprising. First, web surfers do not often click links! The “mean” user clicks a link once for every three pages. Such behavior may suggest that search and bookmarks are the prevalent means of navigating the web. Second, the distribution and its fits extend to α = 1. In all the nonlinear least squares variations, the right endpoint of each fit was 1. Thus, long browsing sessions are common on the web. In closing, we repeat that A can be measured from data, and A ∼ Beta(1.5, 0.5, [0, 1]) is a reasonable approximation. While this analysis is preliminary, it supports a few surprising observations about random surfer browsing on the web. 4.6 algorithms In this section we describe and compare three methods for computing the approximate statistics, E [x(A)] and Std [x(A)], of the RAPr model. 4.6.1 PageRank One key component of these algorithms is a robust solver for a determin- istic PageRank problem with α < 1. For this task, we use two solvers: a direct method and an inner-outer method (chapter 5). The direct method uses the “backslash” solve in Matlab. In versions R2007a and R2007b, this command calls the umfpack 5.0 library [Davis, 2004]. For a row sub-stochastic matrix,16 we solve (I − αPT)y = v, x(α) = y/∥y∥ . (4.20) The inner-outer iteration requires only sub-stochastic matrix-vector prod- ucts, which makes it a natural choice for data structure-free algorithms.17 Program 8 is our implementation of the inner-outer method. Using the same code, the inoutpr function works with a native Matlab sparse matrix struc- ture as well as a Matlab wrapper around a BVGraph data structure [Boldi 16 For computational efficiency, all the Matlab programming uses row sub-stochastic matrices; see section 2.4.2 for more information. 17 Although using Gauss-Seidel iterations or a strong-component decomposition algorithm is typi- cally faster, these algorithms require access to the graph as a structure and manipulate it.PDF Image | Instagram Cheat Sheet
PDF Search Title:
Instagram Cheat SheetOriginal File Name Searched:
pagerank-sensitivity-thesis-online.pdfDIY PDF Search: Google It | Yahoo | Bing
Cruise Ship Reviews | Luxury Resort | Jet | Yacht | and Travel Tech More Info
Cruising Review Topics and Articles More Info
Software based on Filemaker for the travel industry More Info
The Burgenstock Resort: Reviews on CruisingReview website... More Info
Resort Reviews: World Class resorts... More Info
The Riffelalp Resort: Reviews on CruisingReview website... More Info
| CONTACT TEL: 608-238-6001 Email: greg@cruisingreview.com | RSS | AMP |