A crawling Remotely Operated Vehicle (ROV) has been developed for scientific activities within coastal and estuarine regions of the ocean for multiple research activities such as environmental impact assessment and integrated coastal zone management. The Modular Amphibious Research Crawler (MARC-1) ROV is designed to operate underwater and in the surfzone to a depth of five meters. The vehicle ...

The key motions of land and water are analyzed for a designed amphibious carrier robot. On land, based on the characteristics multi-joint crawler, robot has planned two gaits climbing steps land. kinematic models established gaits, maximum height that can climb is obtained based, Based laws dynamics, stability equation under strong transient impact to obtain conditions maintain its own when dur...

Vertical search engines allow users to query for information within a subset of documents relevant to a pre-determined topic (Chakrabarti, 1999). One challenging aspect to deploying a vertical search engine is building a Web crawler that distinguishes relevant documents from non-relevant documents. In this research, we describe and analyze various methods to crawl relevant documents for vertica...

In this paper we introduce a probabilistic-reasoning approach to detect Web robots (crawlers) from human visitors of Web sites. Our approach employs a Naive Bayes network to classify the HTTP sessions of a Web-server access log as crawler or human induced. The Bayesian network combines various pieces of evidence that were shown to distinguish between crawler and human HTTP traffic. The paramete...

Search engines are the most important search tools for finding useful and recent information on the Web today. They rely on crawlers that continually crawl the Web for new pages. Meanwhile, focused crawlers have become an attractive area for research in recent years. They suggest a better solution for general-purpose search engine limitations and lead to a new generation of search engines calle...

A key issue in designing a focused Web crawler is how to determine whether an unvisited URL is relevant to the search topic. Effective relevance prediction can help avoid downloading and visiting many irrelevant pages. In this module, we propose a new learning-based approach to improve relevance prediction in focused Web crawlers. For this study, we chose Naïve Bayesian as the base prediction m...

The World Wide Web is growing rapidly and many search engines do not cover all the visible pages. Therefore, a more effective crawling method is required to collect more accurate data. In this paper, we introduce an effective focused web crawler containing smart methods. In text analysis, similarity measurement applies to different parts of the Web pages including title, body, anchor text and U...

To improve the unstructured terrain traversing performance of scientific research robot Qinghai–Tibet Plateau station, parameters track shoe reconfigurable wheel-crawler walking mechanism were studied. Based on a typical puncture effect model, experimental design was carried out based surface response method, and dynamic model triangular crawler mode constructed tested using RecurDyn V9R3 softw...

In this paper, we present a characterization study of search-engine crawlers. For the purposes of our work, we use Web-server access logs from five academic sites in three different countries. Based on these logs, we analyze the activity of different crawlers that belong to five search engines: Google, AltaVista, Inktomi, FastSearch and CiteSeer. We compare crawler behavior to the characteristi...

A novel active transposable element, designated Crawler, has been isolated from an industrial strain (OSI1013) of Aspergillus oryzae as an insertion sequence within the niaD gene encoding nitrate reductase. It is 1290bp in length with imperfect terminal inverted repeats of 28bp and is flanked by 2bp (TA) target site duplications. It contains an open reading frame with no introns that encodes a ...