Information Retrieval deals with searching and retrieving information within the documents and it also searches the online databases and internet. Web crawler is defined as a program or software which traverses the Web and downloads web documents in a methodical, automated manner. Based on the type of knowledge, web crawler is usually divided in three types of crawling techniques: General Purpo...

The functions of the crawler for mining and driving are all remotely controlled from the control computers on the ship. Various sensors allow comprehensive monitoring of the performance of the crawler. The crawler computer is based on PC/104 modules in connection with a standard industrial field bus system (Interbus) for data acquisition and control. The software used in the sand mining system ...

Crawling web applications is important for indexing, accessibility and security assessment. Crawling traditional web applications is an old problem, for which good and efficient solution are known. Crawling Rich Internet Applications (RIA) quickly and efficiently, however, is an open problem. Technologies such as AJAX and partial Document Object Model (DOM) updates only make the problem of craw...

Web crawlers are complex applications that explore the Web with different purposes. Web crawlers can be configured to crawl online social networks (OSN) to obtain relevant data about its global structure. Before a web crawler can be launched to explore the web, a large amount of settings have to be configured. This settings define the behavior of the crawler and have a big impact on the collect...

In this paper we study how to build an effective incremental crawler. The crawler selectively and incrementally updates its index and/or local collection of web pages, instead of periodically refreshing the collection in batch mode. The incremental crawler can improve the “freshness” of the collection significantly and bring in new pages in a more timely manner. We first present results from an...

A focused crawler may be described as a crawler which returns relevant web pages on a given topic in traversing the web. Web Crawlers are one of the most crucial part of the Search Engines to collect pages from the Web. The requirement of a web crawler that downloads most relevant web pages from such a large web is still a major challenge in the field of Information Retrieval Systems. Most Web ...

Programming Project A/B – Language-specific word crawler / word list manager The task is to program an efficient language-specific word crawler. It may be based on a language-specific web page crawler, which is described below (Talvensaari 2008). The web pages may then be split into words and organized into a data structure giving words and their frequencies. Such a word list is needed for a cr...

This dissertation studies the challenges and issues faced in implementing an effective Web crawler. A crawler is a program that retrieves and stores pages from the Web, commonly for a Web search engine. A crawler often has to download hundreds of millions of pages in a short period of time and has to constantly monitor and refresh the downloaded pages. In addition, the crawler should avoid putt...

A Web crawler is a module of a search engine that fetches data from various servers. Web crawlers are an essential component to search engines; running a web crawler is a challenging task. It is a time-taking process to gather data from various sources around the world. Such a single process faces limitations on the processing power of a single machine and one network connection. This module de...