Document (#32980)

Author

Cheng, C.-S.
Chung, C.-P.
Shann, J.J.-J.

Title

Fast query evaluation through document identifier assignment for inverted file-based information retrieval systems

Source

Information processing and management. 42(2006) no.3, S.729-750

Year

2006

Abstract

Compressing an inverted file can greatly improve query performance of an information retrieval system (IRS) by reducing disk I/Os. We observe that a good document identifier assignment (DIA) can make the document identifiers in the posting lists more clustered, and result in better compression as well as shorter query processing time. In this paper, we tackle the NP-complete problem of finding an optimal DIA to minimize the average query processing time in an IRS when the probability distribution of query terms is given. We indicate that the greedy nearest neighbor (Greedy-NN) algorithm can provide excellent performance for this problem. However, the Greedy-NN algorithm is inappropriate if used in large-scale IRSs, due to its high complexity O(N2 × n), where N denotes the number of documents and n denotes the number of distinct terms. In real-world IRSs, the distribution of query terms is skewed. Based on this fact, we propose a fast O(N × n) heuristic, called partition-based document identifier assignment (PBDIA) algorithm, which can efficiently assign consecutive document identifiers to those documents containing frequently used query terms, and improve compression efficiency of the posting lists for those terms. This can result in reduced query processing time. The experimental results show that the PBDIA algorithm can yield a competitive performance versus the Greedy-NN for the DIA problem, and that this optimization problem has significant advantages for both long queries and parallel information retrieval (IR).

Theme

Retrievalalgorithmen

Similar documents (author)

1. Cheng, L.R.L.: Beyond bilingualism : a quest for communicative competence (1996) 1.88

   1.876745 = sum of:
     1.876745 = product of:
       3.75349 = sum of:
         3.75349 = weight(author_txt:cheng in 5291) [ClassicSimilarity], result of:
           3.75349 = score(doc=5291,freq=1.0), product of:
             0.72059757 = queryWeight, product of:
               1.0194572 = boost
               8.334172 = idf(docFreq=28, maxDocs=44421)
               0.08481278 = queryNorm
             5.2088575 = fieldWeight in 5291, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.334172 = idf(docFreq=28, maxDocs=44421)
               0.625 = fieldNorm(doc=5291)
       0.5 = coord(1/2)
   

2. Chung, T.M.: ¬A corpus comparison approach for terminology extraction (2003) 1.77

   1.7713249 = sum of:
     1.7713249 = product of:
       3.5426497 = sum of:
         3.5426497 = weight(author_txt:chung in 5072) [ClassicSimilarity], result of:
           3.5426497 = score(doc=5072,freq=1.0), product of:
             0.6933536 = queryWeight, product of:
               8.175107 = idf(docFreq=33, maxDocs=44421)
               0.08481278 = queryNorm
             5.1094418 = fieldWeight in 5072, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.175107 = idf(docFreq=33, maxDocs=44421)
               0.625 = fieldNorm(doc=5072)
       0.5 = coord(1/2)
   

3. Chung, H.H.: User friendly audiovisual material cataloging at Westchester County Public Library System (2001) 1.77

   1.7713249 = sum of:
     1.7713249 = product of:
       3.5426497 = sum of:
         3.5426497 = weight(author_txt:chung in 415) [ClassicSimilarity], result of:
           3.5426497 = score(doc=415,freq=1.0), product of:
             0.6933536 = queryWeight, product of:
               8.175107 = idf(docFreq=33, maxDocs=44421)
               0.08481278 = queryNorm
             5.1094418 = fieldWeight in 415, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.175107 = idf(docFreq=33, maxDocs=44421)
               0.625 = fieldNorm(doc=415)
       0.5 = coord(1/2)
   

4. Cheng, P.T.K.; Wu, A.K.W.: ACS: an automatic classification system (1995) 1.50

   1.5013961 = sum of:
     1.5013961 = product of:
       3.0027921 = sum of:
         3.0027921 = weight(author_txt:cheng in 2256) [ClassicSimilarity], result of:
           3.0027921 = score(doc=2256,freq=1.0), product of:
             0.72059757 = queryWeight, product of:
               1.0194572 = boost
               8.334172 = idf(docFreq=28, maxDocs=44421)
               0.08481278 = queryNorm
             4.167086 = fieldWeight in 2256, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.334172 = idf(docFreq=28, maxDocs=44421)
               0.5 = fieldNorm(doc=2256)
       0.5 = coord(1/2)
   

5. Cheng, K.-H.: Automatic identification for topics of electronic documents (1997) 1.50

   1.5013961 = sum of:
     1.5013961 = product of:
       3.0027921 = sum of:
         3.0027921 = weight(author_txt:cheng in 2811) [ClassicSimilarity], result of:
           3.0027921 = score(doc=2811,freq=1.0), product of:
             0.72059757 = queryWeight, product of:
               1.0194572 = boost
               8.334172 = idf(docFreq=28, maxDocs=44421)
               0.08481278 = queryNorm
             4.167086 = fieldWeight in 2811, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               8.334172 = idf(docFreq=28, maxDocs=44421)
               0.5 = fieldNorm(doc=2811)
       0.5 = coord(1/2)
   

Similar documents (content)

1. MacFarlane, A.; McCann, J.A.; Robertson, S.E.: Parallel methods for the update of partitioned inverted files (2007) 0.29

   0.28587392 = sum of:
     0.28587392 = product of:
       0.7940942 = sum of:
         0.017213099 = weight(abstract_txt:retrieval in 1819) [ClassicSimilarity], result of:
           0.017213099 = score(doc=1819,freq=2.0), product of:
             0.056017254 = queryWeight, product of:
               1.0519105 = boost
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.015317955 = queryNorm
             0.3072821 = fieldWeight in 1819, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.0625 = fieldNorm(doc=1819)
         0.033613626 = weight(abstract_txt:file in 1819) [ClassicSimilarity], result of:
           0.033613626 = score(doc=1819,freq=1.0), product of:
             0.09632498 = queryWeight, product of:
               1.1262679 = boost
               5.58337 = idf(docFreq=453, maxDocs=44421)
               0.015317955 = queryNorm
             0.34896064 = fieldWeight in 1819, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.58337 = idf(docFreq=453, maxDocs=44421)
               0.0625 = fieldNorm(doc=1819)
         0.03734132 = weight(abstract_txt:fast in 1819) [ClassicSimilarity], result of:
           0.03734132 = score(doc=1819,freq=1.0), product of:
             0.10332096 = queryWeight, product of:
               1.166451 = boost
               5.7825737 = idf(docFreq=371, maxDocs=44421)
               0.015317955 = queryNorm
             0.36141086 = fieldWeight in 1819, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.7825737 = idf(docFreq=371, maxDocs=44421)
               0.0625 = fieldNorm(doc=1819)
         0.009512509 = weight(abstract_txt:this in 1819) [ClassicSimilarity], result of:
           0.009512509 = score(doc=1819,freq=2.0), product of:
             0.044726208 = queryWeight, product of:
               1.213454 = boost
               2.4062347 = idf(docFreq=10885, maxDocs=44421)
               0.015317955 = queryNorm
             0.21268311 = fieldWeight in 1819, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               2.4062347 = idf(docFreq=10885, maxDocs=44421)
               0.0625 = fieldNorm(doc=1819)
         0.04893737 = weight(abstract_txt:processing in 1819) [ClassicSimilarity], result of:
           0.04893737 = score(doc=1819,freq=2.0), product of:
             0.112419814 = queryWeight, product of:
               1.4901819 = boost
               4.9249606 = idf(docFreq=876, maxDocs=44421)
               0.015317955 = queryNorm
             0.4353091 = fieldWeight in 1819, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.9249606 = idf(docFreq=876, maxDocs=44421)
               0.0625 = fieldNorm(doc=1819)
         0.21395692 = weight(abstract_txt:inverted in 1819) [ClassicSimilarity], result of:
           0.21395692 = score(doc=1819,freq=6.0), product of:
             0.18206613 = queryWeight, product of:
               1.548413 = boost
               7.676116 = idf(docFreq=55, maxDocs=44421)
               0.015317955 = queryNorm
             1.1751605 = fieldWeight in 1819, product of:
               2.4494898 = tf(freq=6.0), with freq of:
                 6.0 = termFreq=6.0
               7.676116 = idf(docFreq=55, maxDocs=44421)
               0.0625 = fieldNorm(doc=1819)
         0.05406456 = weight(abstract_txt:document in 1819) [ClassicSimilarity], result of:
           0.05406456 = score(doc=1819,freq=2.0), product of:
             0.1424428 = queryWeight, product of:
               2.1655214 = boost
               4.29415 = idf(docFreq=1647, maxDocs=44421)
               0.015317955 = queryNorm
             0.3795528 = fieldWeight in 1819, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.29415 = idf(docFreq=1647, maxDocs=44421)
               0.0625 = fieldNorm(doc=1819)
         0.2620426 = weight(abstract_txt:identifier in 1819) [ClassicSimilarity], result of:
           0.2620426 = score(doc=1819,freq=4.0), product of:
             0.27309915 = queryWeight, product of:
               2.3226194 = boost
               7.676116 = idf(docFreq=55, maxDocs=44421)
               0.015317955 = queryNorm
             0.9595145 = fieldWeight in 1819, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               7.676116 = idf(docFreq=55, maxDocs=44421)
               0.0625 = fieldNorm(doc=1819)
         0.11741223 = weight(abstract_txt:query in 1819) [ClassicSimilarity], result of:
           0.11741223 = score(doc=1819,freq=2.0), product of:
             0.27939218 = queryWeight, product of:
               3.836272 = boost
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.015317955 = queryNorm
             0.42024165 = fieldWeight in 1819, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.0625 = fieldNorm(doc=1819)
       0.36 = coord(9/25)
   

2. Moffat, A.; Zobel, J.: Self-indexing inverted files for fast text retrieval (1996) 0.26

   0.25966203 = sum of:
     0.25966203 = product of:
       0.6491551 = sum of:
         0.021081654 = weight(abstract_txt:retrieval in 1009) [ClassicSimilarity], result of:
           0.021081654 = score(doc=1009,freq=3.0), product of:
             0.056017254 = queryWeight, product of:
               1.0519105 = boost
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.015317955 = queryNorm
             0.37634215 = fieldWeight in 1009, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.0625 = fieldNorm(doc=1009)
         0.03258101 = weight(abstract_txt:lists in 1009) [ClassicSimilarity], result of:
           0.03258101 = score(doc=1009,freq=1.0), product of:
             0.09434199 = queryWeight, product of:
               1.1146147 = boost
               5.5256004 = idf(docFreq=480, maxDocs=44421)
               0.015317955 = queryNorm
             0.34535003 = fieldWeight in 1009, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.5256004 = idf(docFreq=480, maxDocs=44421)
               0.0625 = fieldNorm(doc=1009)
         0.033613626 = weight(abstract_txt:file in 1009) [ClassicSimilarity], result of:
           0.033613626 = score(doc=1009,freq=1.0), product of:
             0.09632498 = queryWeight, product of:
               1.1262679 = boost
               5.58337 = idf(docFreq=453, maxDocs=44421)
               0.015317955 = queryNorm
             0.34896064 = fieldWeight in 1009, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.58337 = idf(docFreq=453, maxDocs=44421)
               0.0625 = fieldNorm(doc=1009)
         0.009512509 = weight(abstract_txt:this in 1009) [ClassicSimilarity], result of:
           0.009512509 = score(doc=1009,freq=2.0), product of:
             0.044726208 = queryWeight, product of:
               1.213454 = boost
               2.4062347 = idf(docFreq=10885, maxDocs=44421)
               0.015317955 = queryNorm
             0.21268311 = fieldWeight in 1009, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               2.4062347 = idf(docFreq=10885, maxDocs=44421)
               0.0625 = fieldNorm(doc=1009)
         0.04625303 = weight(abstract_txt:time in 1009) [ClassicSimilarity], result of:
           0.04625303 = score(doc=1009,freq=5.0), product of:
             0.079774216 = queryWeight, product of:
               1.2553047 = boost
               4.1487055 = idf(docFreq=1905, maxDocs=44421)
               0.015317955 = queryNorm
             0.57979923 = fieldWeight in 1009, product of:
               2.236068 = tf(freq=5.0), with freq of:
                 5.0 = termFreq=5.0
               4.1487055 = idf(docFreq=1905, maxDocs=44421)
               0.0625 = fieldNorm(doc=1009)
         0.04893737 = weight(abstract_txt:processing in 1009) [ClassicSimilarity], result of:
           0.04893737 = score(doc=1009,freq=2.0), product of:
             0.112419814 = queryWeight, product of:
               1.4901819 = boost
               4.9249606 = idf(docFreq=876, maxDocs=44421)
               0.015317955 = queryNorm
             0.4353091 = fieldWeight in 1009, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.9249606 = idf(docFreq=876, maxDocs=44421)
               0.0625 = fieldNorm(doc=1009)
         0.08338811 = weight(abstract_txt:compression in 1009) [ClassicSimilarity], result of:
           0.08338811 = score(doc=1009,freq=1.0), product of:
             0.1765217 = queryWeight, product of:
               1.524654 = boost
               7.558333 = idf(docFreq=62, maxDocs=44421)
               0.015317955 = queryNorm
             0.4723958 = fieldWeight in 1009, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               7.558333 = idf(docFreq=62, maxDocs=44421)
               0.0625 = fieldNorm(doc=1009)
         0.17469509 = weight(abstract_txt:inverted in 1009) [ClassicSimilarity], result of:
           0.17469509 = score(doc=1009,freq=4.0), product of:
             0.18206613 = queryWeight, product of:
               1.548413 = boost
               7.676116 = idf(docFreq=55, maxDocs=44421)
               0.015317955 = queryNorm
             0.9595145 = fieldWeight in 1009, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               7.676116 = idf(docFreq=55, maxDocs=44421)
               0.0625 = fieldNorm(doc=1009)
         0.055292662 = weight(abstract_txt:terms in 1009) [ClassicSimilarity], result of:
           0.055292662 = score(doc=1009,freq=3.0), product of:
             0.12631258 = queryWeight, product of:
               2.039227 = boost
               4.043712 = idf(docFreq=2116, maxDocs=44421)
               0.015317955 = queryNorm
             0.43774468 = fieldWeight in 1009, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               4.043712 = idf(docFreq=2116, maxDocs=44421)
               0.0625 = fieldNorm(doc=1009)
         0.14380004 = weight(abstract_txt:query in 1009) [ClassicSimilarity], result of:
           0.14380004 = score(doc=1009,freq=3.0), product of:
             0.27939218 = queryWeight, product of:
               3.836272 = boost
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.015317955 = queryNorm
             0.51468885 = fieldWeight in 1009, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.0625 = fieldNorm(doc=1009)
       0.4 = coord(10/25)
   

3. Bian, G.-W.; Chen, H.-H.: Cross-language information access to multilingual collections on the Internet (2000) 0.21

   0.20744161 = sum of:
     0.20744161 = product of:
       0.51860404 = sum of:
         0.03192435 = weight(abstract_txt:result in 5436) [ClassicSimilarity], result of:
           0.03192435 = score(doc=5436,freq=1.0), product of:
             0.08020535 = queryWeight, product of:
               1.027718 = boost
               5.0948176 = idf(docFreq=739, maxDocs=44421)
               0.015317955 = queryNorm
             0.39803264 = fieldWeight in 5436, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.0948176 = idf(docFreq=739, maxDocs=44421)
               0.078125 = fieldNorm(doc=5436)
         0.015214373 = weight(abstract_txt:retrieval in 5436) [ClassicSimilarity], result of:
           0.015214373 = score(doc=5436,freq=1.0), product of:
             0.056017254 = queryWeight, product of:
               1.0519105 = boost
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.015317955 = queryNorm
             0.27160156 = fieldWeight in 5436, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               3.4765 = idf(docFreq=3732, maxDocs=44421)
               0.078125 = fieldNorm(doc=5436)
         0.0084079495 = weight(abstract_txt:this in 5436) [ClassicSimilarity], result of:
           0.0084079495 = score(doc=5436,freq=1.0), product of:
             0.044726208 = queryWeight, product of:
               1.213454 = boost
               2.4062347 = idf(docFreq=10885, maxDocs=44421)
               0.015317955 = queryNorm
             0.18798709 = fieldWeight in 5436, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               2.4062347 = idf(docFreq=10885, maxDocs=44421)
               0.078125 = fieldNorm(doc=5436)
         0.025856227 = weight(abstract_txt:time in 5436) [ClassicSimilarity], result of:
           0.025856227 = score(doc=5436,freq=1.0), product of:
             0.079774216 = queryWeight, product of:
               1.2553047 = boost
               4.1487055 = idf(docFreq=1905, maxDocs=44421)
               0.015317955 = queryNorm
             0.3241176 = fieldWeight in 5436, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.1487055 = idf(docFreq=1905, maxDocs=44421)
               0.078125 = fieldNorm(doc=5436)
         0.050489422 = weight(abstract_txt:performance in 5436) [ClassicSimilarity], result of:
           0.050489422 = score(doc=5436,freq=2.0), product of:
             0.09891816 = queryWeight, product of:
               1.397835 = boost
               4.619759 = idf(docFreq=1189, maxDocs=44421)
               0.015317955 = queryNorm
             0.5104161 = fieldWeight in 5436, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.619759 = idf(docFreq=1189, maxDocs=44421)
               0.078125 = fieldNorm(doc=5436)
         0.042814527 = weight(abstract_txt:problem in 5436) [ClassicSimilarity], result of:
           0.042814527 = score(doc=5436,freq=1.0), product of:
             0.12289271 = queryWeight, product of:
               1.7990793 = boost
               4.4593854 = idf(docFreq=1396, maxDocs=44421)
               0.015317955 = queryNorm
             0.34838948 = fieldWeight in 5436, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.4593854 = idf(docFreq=1396, maxDocs=44421)
               0.078125 = fieldNorm(doc=5436)
         0.039904043 = weight(abstract_txt:terms in 5436) [ClassicSimilarity], result of:
           0.039904043 = score(doc=5436,freq=1.0), product of:
             0.12631258 = queryWeight, product of:
               2.039227 = boost
               4.043712 = idf(docFreq=2116, maxDocs=44421)
               0.015317955 = queryNorm
             0.31591502 = fieldWeight in 5436, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.043712 = idf(docFreq=2116, maxDocs=44421)
               0.078125 = fieldNorm(doc=5436)
         0.06758071 = weight(abstract_txt:document in 5436) [ClassicSimilarity], result of:
           0.06758071 = score(doc=5436,freq=2.0), product of:
             0.1424428 = queryWeight, product of:
               2.1655214 = boost
               4.29415 = idf(docFreq=1647, maxDocs=44421)
               0.015317955 = queryNorm
             0.47444102 = fieldWeight in 5436, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.29415 = idf(docFreq=1647, maxDocs=44421)
               0.078125 = fieldNorm(doc=5436)
         0.08964718 = weight(abstract_txt:algorithm in 5436) [ClassicSimilarity], result of:
           0.08964718 = score(doc=5436,freq=1.0), product of:
             0.20113598 = queryWeight, product of:
               2.3016121 = boost
               5.7050157 = idf(docFreq=401, maxDocs=44421)
               0.015317955 = queryNorm
             0.44570434 = fieldWeight in 5436, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.7050157 = idf(docFreq=401, maxDocs=44421)
               0.078125 = fieldNorm(doc=5436)
         0.14676529 = weight(abstract_txt:query in 5436) [ClassicSimilarity], result of:
           0.14676529 = score(doc=5436,freq=2.0), product of:
             0.27939218 = queryWeight, product of:
               3.836272 = boost
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.015317955 = queryNorm
             0.52530205 = fieldWeight in 5436, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.078125 = fieldNorm(doc=5436)
       0.4 = coord(10/25)
   

4. Zhao, L.; Wu, L.; Huang, X.: Using query expansion in graph-based approach for query-focused multi-document summarization (2009) 0.19

   0.19437751 = sum of:
     0.19437751 = product of:
       0.60742974 = sum of:
         0.04159252 = weight(abstract_txt:improve in 3449) [ClassicSimilarity], result of:
           0.04159252 = score(doc=3449,freq=2.0), product of:
             0.07593736 = queryWeight, product of:
               4.9574084 = idf(docFreq=848, maxDocs=44421)
               0.015317955 = queryNorm
             0.54772145 = fieldWeight in 3449, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.9574084 = idf(docFreq=848, maxDocs=44421)
               0.078125 = fieldNorm(doc=3449)
         0.03192435 = weight(abstract_txt:result in 3449) [ClassicSimilarity], result of:
           0.03192435 = score(doc=3449,freq=1.0), product of:
             0.08020535 = queryWeight, product of:
               1.027718 = boost
               5.0948176 = idf(docFreq=739, maxDocs=44421)
               0.015317955 = queryNorm
             0.39803264 = fieldWeight in 3449, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.0948176 = idf(docFreq=739, maxDocs=44421)
               0.078125 = fieldNorm(doc=3449)
         0.0084079495 = weight(abstract_txt:this in 3449) [ClassicSimilarity], result of:
           0.0084079495 = score(doc=3449,freq=1.0), product of:
             0.044726208 = queryWeight, product of:
               1.213454 = boost
               2.4062347 = idf(docFreq=10885, maxDocs=44421)
               0.015317955 = queryNorm
             0.18798709 = fieldWeight in 3449, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               2.4062347 = idf(docFreq=10885, maxDocs=44421)
               0.078125 = fieldNorm(doc=3449)
         0.035701413 = weight(abstract_txt:performance in 3449) [ClassicSimilarity], result of:
           0.035701413 = score(doc=3449,freq=1.0), product of:
             0.09891816 = queryWeight, product of:
               1.397835 = boost
               4.619759 = idf(docFreq=1189, maxDocs=44421)
               0.015317955 = queryNorm
             0.36091867 = fieldWeight in 3449, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.619759 = idf(docFreq=1189, maxDocs=44421)
               0.078125 = fieldNorm(doc=3449)
         0.042814527 = weight(abstract_txt:problem in 3449) [ClassicSimilarity], result of:
           0.042814527 = score(doc=3449,freq=1.0), product of:
             0.12289271 = queryWeight, product of:
               1.7990793 = boost
               4.4593854 = idf(docFreq=1396, maxDocs=44421)
               0.015317955 = queryNorm
             0.34838948 = fieldWeight in 3449, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.4593854 = idf(docFreq=1396, maxDocs=44421)
               0.078125 = fieldNorm(doc=3449)
         0.08276912 = weight(abstract_txt:document in 3449) [ClassicSimilarity], result of:
           0.08276912 = score(doc=3449,freq=3.0), product of:
             0.1424428 = queryWeight, product of:
               2.1655214 = boost
               4.29415 = idf(docFreq=1647, maxDocs=44421)
               0.015317955 = queryNorm
             0.5810692 = fieldWeight in 3449, product of:
               1.7320508 = tf(freq=3.0), with freq of:
                 3.0 = termFreq=3.0
               4.29415 = idf(docFreq=1647, maxDocs=44421)
               0.078125 = fieldNorm(doc=3449)
         0.08964718 = weight(abstract_txt:algorithm in 3449) [ClassicSimilarity], result of:
           0.08964718 = score(doc=3449,freq=1.0), product of:
             0.20113598 = queryWeight, product of:
               2.3016121 = boost
               5.7050157 = idf(docFreq=401, maxDocs=44421)
               0.015317955 = queryNorm
             0.44570434 = fieldWeight in 3449, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.7050157 = idf(docFreq=401, maxDocs=44421)
               0.078125 = fieldNorm(doc=3449)
         0.27457273 = weight(abstract_txt:query in 3449) [ClassicSimilarity], result of:
           0.27457273 = score(doc=3449,freq=7.0), product of:
             0.27939218 = queryWeight, product of:
               3.836272 = boost
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.015317955 = queryNorm
             0.9827502 = fieldWeight in 3449, product of:
               2.6457512 = tf(freq=7.0), with freq of:
                 7.0 = termFreq=7.0
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.078125 = fieldNorm(doc=3449)
       0.32 = coord(8/25)
   

5. Abdi, A.; Shamsuddin, S.M.; Aliguliyev, R.M.: QMOS: Query-based multi-documents opinion-oriented summarization (2018) 0.17

   0.1748798 = sum of:
     0.1748798 = product of:
       0.6245707 = sum of:
         0.029114764 = weight(abstract_txt:improve in 89) [ClassicSimilarity], result of:
           0.029114764 = score(doc=89,freq=2.0), product of:
             0.07593736 = queryWeight, product of:
               4.9574084 = idf(docFreq=848, maxDocs=44421)
               0.015317955 = queryNorm
             0.383405 = fieldWeight in 89, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.9574084 = idf(docFreq=848, maxDocs=44421)
               0.0546875 = fieldNorm(doc=89)
         0.008323446 = weight(abstract_txt:this in 89) [ClassicSimilarity], result of:
           0.008323446 = score(doc=89,freq=2.0), product of:
             0.044726208 = queryWeight, product of:
               1.213454 = boost
               2.4062347 = idf(docFreq=10885, maxDocs=44421)
               0.015317955 = queryNorm
             0.18609773 = fieldWeight in 89, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               2.4062347 = idf(docFreq=10885, maxDocs=44421)
               0.0546875 = fieldNorm(doc=89)
         0.035342593 = weight(abstract_txt:performance in 89) [ClassicSimilarity], result of:
           0.035342593 = score(doc=89,freq=2.0), product of:
             0.09891816 = queryWeight, product of:
               1.397835 = boost
               4.619759 = idf(docFreq=1189, maxDocs=44421)
               0.015317955 = queryNorm
             0.35729125 = fieldWeight in 89, product of:
               1.4142135 = tf(freq=2.0), with freq of:
                 2.0 = termFreq=2.0
               4.619759 = idf(docFreq=1189, maxDocs=44421)
               0.0546875 = fieldNorm(doc=89)
         0.029970169 = weight(abstract_txt:problem in 89) [ClassicSimilarity], result of:
           0.029970169 = score(doc=89,freq=1.0), product of:
             0.12289271 = queryWeight, product of:
               1.7990793 = boost
               4.4593854 = idf(docFreq=1396, maxDocs=44421)
               0.015317955 = queryNorm
             0.24387264 = fieldWeight in 89, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               4.4593854 = idf(docFreq=1396, maxDocs=44421)
               0.0546875 = fieldNorm(doc=89)
         0.06275302 = weight(abstract_txt:algorithm in 89) [ClassicSimilarity], result of:
           0.06275302 = score(doc=89,freq=1.0), product of:
             0.20113598 = queryWeight, product of:
               2.3016121 = boost
               5.7050157 = idf(docFreq=401, maxDocs=44421)
               0.015317955 = queryNorm
             0.31199303 = fieldWeight in 89, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               5.7050157 = idf(docFreq=401, maxDocs=44421)
               0.0546875 = fieldNorm(doc=89)
         0.14529023 = weight(abstract_txt:query in 89) [ClassicSimilarity], result of:
           0.14529023 = score(doc=89,freq=4.0), product of:
             0.27939218 = queryWeight, product of:
               3.836272 = boost
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.015317955 = queryNorm
             0.5200225 = fieldWeight in 89, product of:
               2.0 = tf(freq=4.0), with freq of:
                 4.0 = termFreq=4.0
               4.754492 = idf(docFreq=1039, maxDocs=44421)
               0.0546875 = fieldNorm(doc=89)
         0.3137765 = weight(abstract_txt:greedy in 89) [ClassicSimilarity], result of:
           0.3137765 = score(doc=89,freq=1.0), product of:
             0.58813936 = queryWeight, product of:
               3.9357488 = boost
               9.755557 = idf(docFreq=6, maxDocs=44421)
               0.015317955 = queryNorm
             0.53350705 = fieldWeight in 89, product of:
               1.0 = tf(freq=1.0), with freq of:
                 1.0 = termFreq=1.0
               9.755557 = idf(docFreq=6, maxDocs=44421)
               0.0546875 = fieldNorm(doc=89)
       0.28 = coord(7/25)