Fox E.A., Chen Q.F. and Heath L.S.: "A Faster Algorithm for Constructing Minimal Perfect Hash Functions", 15th ACM SIGIR Conference Proceedings, pp. 266-273, 1992.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....means that the universe in question can be reduced to size O(n for truly random functions makes this unsuitable for implementation, one has to settle for pseudo random functions in practice. Empirical studies show that limited randomness properties are often as good as total randomness. Fox et al. [6, 7] studied some classes which share several features with the one presented here. Their results indicate convincing practical performance, and suggest that it is possible to bring down the storage requirements further than proved here. However, it should be warned that doing well in most cases may ....

Edward A. Fox, Qi Fan Chen, and Lenwood S. Heath. A faster algorithm for constructing minimal perfect hash functions. In Proceedings of the Fifteenth Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Data Structures, pages 266-273, 1992.

....ERSF differ from SC SF in assuming each vocabulary term (i.e. key word) to be mapped on a distinct integer number in the [0, V 1] range, an integer which becomes the ID number of the word in question. This word to integer mapping scheme may be implemented by means of a perfect hash function [4]. Perfect encoding considers the maximum number of messages Bmax agiven(V ,D) configuration may support: Bmax = # V D # Under PE, block signatures are encoded via a binary number in the [0, #log 2Bmax# 1] range. Evidently, PE comprises an upper limit for SC SF with regard to information ....

Fox E.A., Chen Q.F. and Heath L.S.: "A Faster Algorithm for Constructing Minimal Perfect Hash Functions", 15th ACM SIGIR Conference Proceedings, pp. 266-273, 1992.

....accurate, fully reversible intermediary representation of the textual information. Text words are assumed to be taken from a vocabulary of large but finite size V (e.g. V = 30 100,000 words) Each word is mapped on a unique integer w i in the [1. V ] range, e.g. by using a perfect hash function [5]. In accordance with the analysis presented in section 2, the finite vocabulary assumption should not be considered as a drawback for PE. Similarly to SC SF, each PE logical block of text involves a fixed, predetermined number (D) of distinct, non common words drawn from the vocabulary in ....

....scheme in Table 2 involves M value regions which alternate into containing and not containing a given word. For example, considering the single word query q=4: M numbers in [0,4] 15,24] 35,44] etc. correspond to blocks which do not contain q, whereas the blocks encoded by M numbers in [5,14], 25,34] etc. contain the word in question. Table I 1 considers the case where q=6, V =9 and D=4. It presents the kc , Ckc = # V q D kc # and exists values calculated andusedbythePE query processing algorithm in Figure 3. Also listed is information with regard to the w4 , w3 , w2 ....

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Fox E.A., Chen Q.F. and Heath L.S.: "A Faster Algorithm for Constructing Minimal Perfect Hash Functions", 15th ACM SIGIR Conference Proceedings, pp. 266-273, Copenhagen, Denmark, 1992.

....truly random functions [2, 10] Since the space requirements for truly random functions makes this unsuitable for implementation, one has to settle for pseudo random functions in practice. Empirical studies show that limited randomness properties are often as good as total randomness. Fox et al. [6, 7] studied some classes which share several features with the one presented here. Their results indicate convincing practical performance, and suggest that it is possible to bring down the storage requirements further than proved here. However, it should be warned that doing well in most cases may ....

Edward A. Fox, Qi Fan Chen, and Lenwood S. Heath. A faster algorithm for constructing minimal perfect hash functions. In Proceedings of the Fifteenth Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Data Structures, pages 266-273, 1992.

....truly random functions [2, 9] Since the space requirements for truly random functions makes this unsuitable for implementation, one has to settle for pseudo random functions in practice. Empirical studies show that limited randomness properties are often as good as total randomness. Fox et al. [6, 7] studied some classes which share several features with the one presented here. Their results indicate convincing practical performance, and suggest that it is possible to bring down the storage requirements further than proved here. However, it should be warned that doing well in most cases may ....

Edward A. Fox, Qi Fan Chen, and Lenwood S. Heath. A faster algorithm for constructing minimal perfect hash functions. In Proceedings of the Fifteenth Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Data Structures, pages 266-273, 1992.

....may be large, yet must remain finite in size. 4 Information Loss Free Signature Constructs Having assumed a large yet finite textbase plus queries vocabulary (V ) two signature file variations are considered [5] Figure 3 presents the two variations in diagrammatic form. A perfect hash function [9] is utilized which maps each word on a unique integer in the [1, V ] range. Text is seen to consist of logical blocks in a way similar to that of the classical SC SF, D being the blocking factor. It is by construction that the typical block signature pattern is V binary bits long and registers ....

Fox E.A., Chen Q.F. and Heath L.S.: "A Faster Algorithm for Constructing Minimal Perfect Hash Functions", Proceedings ACM SIGIR'92 Conference, pp.266-273, Copenhagen, 1992.

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Fox E.A., Chen Q.F. and Heath L.S.: "A Faster Algorithm for Constructing Minimal Perfect Hash Functions", 15th ACM SIGIR Conference Proceedings, pp. 266-273, 1992.

No context found.

Fox E.A., Chen Q.F. and Heath L.S.: "A Faster Algorithm for Constructing Minimal Perfect Hash Functions", 15th ACM SIGIR Conference Proceedings, pp. 266-273, Copenhagen, Denmark, 1992.

No context found.

E. Fox, Q. Chen, and L. Heath. A faster algorithm for constructing minimal perfect hash functions. In Annual International ACM SIGIR, pages 266--273, 1992.

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Edward A. Fox, Qi Fan Chen, and Lenwood S. Heath. A faster algorithm for constructing minimal perfect hash functions. In Proceedings of the 15th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Data Structures, pages 266--273. ACM Press, 1992.

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