Yasser Ganjisaffar

Microsoft Bing, Senior RSDE I work in Bing's core ranking team	Since Sept 2011
Microsoft Bing, RSDE Intern I worked on improving and optimizing Bing's new ranking algorithm.	Summer 2010
Microsoft Bing, Software Developer Intern I worked on the index sorting problem with the Relevance Infrastructure team.	Summer 2009
Microsoft Live Search, Software Developer Intern I worked on extracting statistically significant phrases from the titles and snippets of web search results.	Summer 2008

• Y. Ganjisaffar, Tree Ensembles for Learning to Rank, PhD thesis, University of California, Irvine, August 2011 [PDF, Slides].
• Y. Ganjisaffar et al., qSpell: Spelling Correction of Web Search Queries using Ranking Models and Iterative Correction, in Spelling Alteration for Web Search Workshop, Bellevue, WA, USA, July 2011 [PDF].
• Y. Ganjisaffar, T. Debeauvais, S. Javanmardi, R. Caruana, C. Lopes, Distributed Tuning of Machine Learning Algorithms using MapReduce Clusters, KDD 2011 workshop on Large-scale Data Mining, San Diego, CA, USA [PDF, Slides].
• Y. Ganjisaffar, R. Caruana, C. Lopes, Bagging Gradient-Boosted Trees for High Precision, Low Variance Ranking Models, in SIGIR 2011, Beijing, China (19.8% acceptance rate) [PDF, Slides].
• S. Javanmardi, Y. Ganjisaffar, S. Grant, C. Lopes, Statistical Measure of the Effectiveness of the Open Editing Model of Wikipedia, in ICWSM 2010 [PDF].
• S. Javanmardi, Y. Ganjisaffar, C. Lopes, P. Baldi , Scientific Mashups: The Issue of Trust in the Aggregation of Web 2.0 Content, WebScience'2010, Raleigh, NC [PDF].
• Y. Ganjisaffar, S. Javanmardi, C. Lopes, Using User Reviews to Improve Search in Wikipedia, SIGIR 2009 Workshop on Search in Social Media, Boston, USA, 2009 [PDF].
• Y. Ganjisaffar, S. Javanmardi, C. Lopes, Leveraging Crowdsourcing Heuristics to Improve Search in Wikipedia, in Proceedings of the 5th International Symposium on Wikis and Open Collaboration (WikiSym), Florida, USA, 2009 [PDF].
• S. Javanmardi, Y. Ganjisaffar, C. Lopes, P. Baldi, User Contribution and Trust in Wikipedia, Proceedings of The 5th International Conference on Collaborative Computing: Networking, Applications and Worksharing , Washington D.C., USA, 2009 [PDF].
• Y. Ganjisaffar, S. Javanmardi, C. Lopes, Review-based Ranking of Wikipedia Articles, in Proceedings of the International Conference on Computational Aspects of Social Networks, Fontainebleau, France, 2009 [PDF].
• Y. Ganjisaffar, S. Javanmardi, S. Grant, C. Lopes, CalSWIM: A Wiki-based Data Sharing Platform, Collaborative Computing: Networking, Applications and Worksharing, Vol. 10, 2009, pp. 34-43 [PDF].
• Y. Ganjisaffar, H. Abolhassani, Towards a Framework for Brokering Semantic Web Services, International Journal of Computers and their applications (IJCA), Vol. 15, No. 4, December 2008, pp. 252-262 [PDF].
• H. R. Shahriari, Y. Ganjisaffar, R. Jalili, and J. Habibi, Topological Analysis of Multi-Phase Attacks using Expert Systems, International Journal of Information Science and Engineering (JISE), Vol. 24, No. 3, May 2008, pp. 743-767 [PDF].
• M. Neshati, Y. Ganjisaffar and H. Abolhassani, Clustering-based Taxonomy Construction for Semantic Web Services, Proceedings of the 12th International CSI Computer Conference (CSICC 2007), Tehran, Iran [PDF].
• Y. Ganjisaffar, H. Abolhassani and M. Neshati, A Similarity Measure for OWL-S annotated Web Services, Proceedings of The 2006 IEEE/WIC/ACM International Conference on Web Intelligence, Hong Kong, 2006, pp. 621-624 [PDF].
• S. Javanmardi, M. Amini, R. Jalili, and Y. Ganjisaffar, SBAC: Semantic Based Access Control, The 11th Nordic Workshop on Secure IT-systems, Linkping, Sweden, October 2006, pp. 157-168 [PDF].
• Y. Ganjisaffar, H. Abolhassani and R. Jalili, An Architecture for a context-aware Service Broker in Ubiquitous Computing Environments, International Workshop on Pervasive Computing Systems & Application (PerCSA 2006), UAE, March 2006, pp. 1097-1100 [PDF].
• Y. Ganjisaffar, K. Sheykh Esmaili, M. Ghodsi and H. Abolhassani, Parallel Online Ranking of Web Pages, The 4th ACS/IEEE International Conference on Computer Systems and Applications (AICCSA-06), UAE, March 2006, pp. 104-109 [PDF].
• Y. Ganjisaffar, H. Abolhassani, Context-aware Semantic Web Service Brokering, 11th International CSI Computer Conference (CSICC 2006), Jan. 2006, Tehran, Iran [PDF].
• H. Shahriari, Y. Ganjisaffar and R. Jalili, A Connectivity Based Method for Analyzing Network Vulnerabilities, Proceedings of the 3rd Iranian Society of Cryptography Conference (ISCC'05), Isfahan, Iran, Sep. 2005, pp 273-284 (Received best paper award).

• Optimizing an index of web documents. U.S. patent, filed March 2011.

• Learning to Rank: How Commercial Search Engines Rank Search Results? [PDF]
• MapReduce, Hadoop, and Amazon AWS [PDF]

jforests: Tree-based Ensembles for Machine Learning
jforests is a Machine Learning framework that includes implementations of popular tree-based learning algorithms (2011)

qSpell: Search Query Spell Correction
Roughly 10-15% of the queries which are sent to web search engines contain spelling errors. This project is an attempt to detect and fix those errors (2011)

lasso4j
The Lasso is a shrinkage and selection method for linear regression. Lasso4j is an open source Java implementation of the Lasso L1-constrained fitting for linear regression. This implementation is based on the glmnet R package which is implemented in Fortran.

crawler4j: An Open Source Web Crawler for Java
A light-weight and very fast web crawler for Java which uses Berkeley DB for managing the frontier queue in a very efficient manner. Crawled the whole English Wikipedia in 10 hours during January 2009.

Wikijoo: A Search Engine for Wikipedia
Wikijoo is a special purpose search engine for Wikipedia which uses a Review-based ranking algorithm in ranking search results (2009).

• Bing Ranking and Intent: Above and Beyond award, March 2012.
• 3rd Prize for Microsoft's Speller Challenge, July 2011 [news story].
• Research grant from Amazon.com for working on "Search Query Spell Correction", March 2011
• Research grant from Amazon.com for working on "Distributed Tuning of Machine Learning Algorithms", Jan 2011
• 6th rank in UCSD Data Mining Competition among more than 90 teams, 2010
• Phd Admission and Fellowship offer from University of Illinois at Urbana Champaign, 2007
• Phd Admission and Fellowship offer for three years from University of California, Irvine, 2007
• PhD Admission with a Fellowship offer for two years of support from University of California, Riverside, 2007.
• Phd Admission and Fellowship offer for two years from University of Alberta, 2007
• 1st Rank in cumulative GPA among M.Sc. students of the department, Fall 2004 beginners, Sharif University of Technology, Fall 2006.
• Best Paper Award, 3rd Iranian Society of Cryptography Conference, ISCC'05, 2005.
• 5th Rank in National Scientific Olympiad in Computer Engineering, Stage II, Tehran, Iran, Summer 2004.
• 2nd Rank in National Scientific Olympiad in Computer Engineering, Stage I, Tehran, Iran, Spring 2004.
• 2nd Rank among over 8,000 students in the National Graduate Entrance Examination in Computer Engineering,
• Accepted in Sharif University of Technology, the best university of Iran.
• Ranked top 0.04% among over 350,000 applicants in Iran's Nationwide University Entrance Examination, Summer 2000.
• 1st Rank in Computer Programming Contest in Kerman Province, 1998.