Change Detection and Notification of Webpages: A Survey <s> Gives notifications to users on time. <s> In this chapter, we argue that push technology is critical for a large number of applications — traditional as well as network-centric. Push technology can be implemented in various ways depending upon the ‘openness’ of the underlying systems into which the push technology is being inserted. We have experimented with several approaches: integrated, mediated (using intelligent agents) and wrapper-based. Intelligent agents are useful for supporting push technology in situations where the underlying system/software provides some hooks but is not open to user modification. In this chapter, we first overview the need for push and pull technologies. We then provide an overview of active capability for detecting changes in databases and other structured environments. <s> BIB001 </s> Change Detection and Notification of Webpages: A Survey <s> Gives notifications to users on time. <s> An end block adapted for use on a kiln car includes a refractory body having a transverse projection at a front end and a transverse recess at a rear end. The recess is dimensioned to receive therewithin a projection on the front end of another block with a loose fit therebetween. A sealing layer of resilient refractory material may be disposed within the recess for contact with the front end projection of another block. <s> BIB002
Optimized space utilization, and efficient way of monitoring types. Can lead to overloading of the servers due to the highly expensive computational cost. WebVigil BIB001 X-Diff [Wang et al. 2003] Compares 2 XML-documents depending on their equivalent trees. It generates a "minimumcost edit script" including a series of fundamental "edit operations" that transform a given tree to the other at a minimum cost. Provide more accurate change results as it maintains an unordered representation of the document where ancestor associations do a notable value addition for the result. May require a large amount of statistical information for the detection process. BIB002 This is a breadth first traversal algorithm and considers the changes in the document tree to detect the changes. Simple. Low cost of computation. Helps to reduce network traffic due to the usage of HTTP metadata. May not give sufficient information to the user.