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Zhang, Y.; Xu, W.: Fast exact maximum likelihood estimation for mixture of language model (2008)
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- Abstract
- Language modeling is an effective and theoretically attractive probabilistic framework for text information retrieval. The basic idea of this approach is to estimate a language model of a given document (or document set), and then do retrieval or classification based on this model. A common language modeling approach assumes the data D is generated from a mixture of several language models. The core problem is to find the maximum likelihood estimation of one language model mixture, given the fixed mixture weights and the other language model mixture. The EM algorithm is usually used to find the solution. In this paper, we proof that an exact maximum likelihood estimation of the unknown mixture component exists and can be calculated using the new algorithm we proposed. We further improve the algorithm and provide an efficient algorithm of O(k) complexity to find the exact solution, where k is the number of words occurring at least once in data D. Furthermore, we proof the probabilities of many words are exactly zeros, and the MLE estimation is implemented as a feature selection technique explicitly.
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Zhang, Y.; Jansen, B.J.; Spink, A.: Identification of factors predicting clickthrough in Web searching using neural network analysis (2009)
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- Date
- 22. 3.2009 17:49:11
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Zhang, Y.; Salaba, A.: Implementing FRBR in libraries : key issues and future directions (2009)
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Zhang, Y.: Using the Internet for survey research : a case study (2000)
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Zhang, Y.; Li, Y.: ¬A user-centered functional metadata evaluation of moving image collections (2008)
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Zhang, X.; Li, Y.; Liu, J.; Zhang, Y.: Effects of interaction design in digital libraries on user interactions (2008)
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Dang, Y.; Zhang, Y.; Chen, H.; Hu, P.J.-H.; Brown, S.A.; Larson, C.: Arizona Literature Mapper : an integrated approach to monitor and analyze global bioterrorism research literature (2009)
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Zhang, Y.: Scholarly use of Internet-based electronic resources (2001)
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Zhang, Y.: ¬The influence of mental models on undergraduate students' searching behavior on the Web (2008)
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Zhang, Y.: Complex adaptive filtering user profile using graphical models (2008)
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Chung, W.; Zhang, Y.; Huang, Z.; Wang, G.; Ong, T.-H.; Chen, H.: Internet searching and browsing in a multilingual world : an experiment an the Chinese Business Intelligence Portal (CBizPort) (2004)
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Tenopir, C.; Wang, P.; Zhang, Y.; Simmons, B.; Pollard, R.: Academic users' interactions with ScienceDirect in search tasks : affective and cognitive behaviors (2008)
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Zhang, Y.: Undergraduate students' mental models of the Web as an information retrieval system (2008)
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Zhang, Y.: ¬The effect of open access on citation impact : a comparison study based on Web citation analysis (2006)
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