• Web Crawler
• Links Extraction
• Page Rank
• TF-IDF
• N-Gram
• Top K
• Inverted Index
• Recommender System
• Sentiment Analysis
• Front page
• Spelling Correction
• Language Identifier
• Auto Completion
• Snippet

1. A well-functional search engine, including Web Crawler, Spelling Correction, Inverted index, PageRank Algorithm, TF-IDF Algorithm, AutoComplete, Recommender System and Sentiment Analysis
2. Web Crawler: Implemented a multithreading web crawler based on crawler4j
3. Page Rank: Extracted out-links from webpages collected by web crawler, built adjacent matrix from hyperlinks of each page, calculated PageRank based on page relation
4. TF-IDF: Parsed HTML pages, extracted content text and computed TF-IDF
5. N-Gram: generated language model, built real-time AutoCompletion based on N-Gram statistics
6. Recommender System: built video rating matrix from dataset, calculated video co-occurrence matrix, based on Item Collaborative Filtering algorithm
7. Sentiment Analysis: Extracted emotion feature from text and implemented sentiment analysis based on emotion dictionary
8. Implemented Top K algorithm and Inverted Index, increased the query efficiency
9. Implemented Spelling Correction
10. UI: built front pages with PHP, Bootstrap and jQuery

enter a query
the result will show up with docID, title, url, description and snippets

AutoCompletion: give user query suggestions

Spelling Correction: When I mis-typing California as californa, it will ask "Are you looking for California"

We can click on the spelling correction hint. It will help us redirect to the correct word.