-
MacFarlane, A.: On open source IR (2003)
0.02
0.021780973 = product of:
0.043561947 = sum of:
0.043561947 = product of:
0.08712389 = sum of:
0.08712389 = weight(_text_:systems in 2010) [ClassicSimilarity], result of:
0.08712389 = score(doc=2010,freq=8.0), product of:
0.16037072 = queryWeight, product of:
3.0731742 = idf(docFreq=5561, maxDocs=44218)
0.052184064 = queryNorm
0.5432656 = fieldWeight in 2010, product of:
2.828427 = tf(freq=8.0), with freq of:
8.0 = termFreq=8.0
3.0731742 = idf(docFreq=5561, maxDocs=44218)
0.0625 = fieldNorm(doc=2010)
0.5 = coord(1/2)
0.5 = coord(1/2)
- Abstract
- Open source software development is becoming increasingly popular as a way of producing software, due to a number of factors. It is argued in this paper that these factors may have a significant impact on the future of information retrieval (IR) systems, and that it is desirable that these systems are made open to all. Some problems are outlined that may prevent the uptake of open source IR systems and a number of open source IR systems are described.
-
MacFarlane, A.; Robertson, S.E.; McCann, J.A.: Parallel computing for passage retrieval (2004)
0.01
0.014140441 = product of:
0.028280882 = sum of:
0.028280882 = product of:
0.056561764 = sum of:
0.056561764 = weight(_text_:22 in 5108) [ClassicSimilarity], result of:
0.056561764 = score(doc=5108,freq=2.0), product of:
0.1827397 = queryWeight, product of:
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.052184064 = queryNorm
0.30952093 = fieldWeight in 5108, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
3.5018296 = idf(docFreq=3622, maxDocs=44218)
0.0625 = fieldNorm(doc=5108)
0.5 = coord(1/2)
0.5 = coord(1/2)
- Date
- 20. 1.2007 18:30:22
-
Lu, W.; MacFarlane, A.; Venuti, F.: Okapi-based XML indexing (2009)
0.01
0.009625921 = product of:
0.019251842 = sum of:
0.019251842 = product of:
0.038503684 = sum of:
0.038503684 = weight(_text_:systems in 3629) [ClassicSimilarity], result of:
0.038503684 = score(doc=3629,freq=4.0), product of:
0.16037072 = queryWeight, product of:
3.0731742 = idf(docFreq=5561, maxDocs=44218)
0.052184064 = queryNorm
0.24009174 = fieldWeight in 3629, product of:
2.0 = tf(freq=4.0), with freq of:
4.0 = termFreq=4.0
3.0731742 = idf(docFreq=5561, maxDocs=44218)
0.0390625 = fieldNorm(doc=3629)
0.5 = coord(1/2)
0.5 = coord(1/2)
- Abstract
- Purpose - Being an important data exchange and information storage standard, XML has generated a great deal of interest and particular attention has been paid to the issue of XML indexing. Clear use cases for structured search in XML have been established. However, most of the research in the area is either based on relational database systems or specialized semi-structured data management systems. This paper aims to propose a method for XML indexing based on the information retrieval (IR) system Okapi. Design/methodology/approach - First, the paper reviews the structure of inverted files and gives an overview of the issues of why this indexing mechanism cannot properly support XML retrieval, using the underlying data structures of Okapi as an example. Then the paper explores a revised method implemented on Okapi using path indexing structures. The paper evaluates these index structures through the metrics of indexing run time, path search run time and space costs using the INEX and Reuters RVC1 collections. Findings - Initial results on the INEX collections show that there is a substantial overhead in space costs for the method, but this increase does not affect run time adversely. Indexing results on differing sized Reuters RVC1 sub-collections show that the increase in space costs with increasing the size of a collection is significant, but in terms of run time the increase is linear. Path search results show sub-millisecond run times, demonstrating minimal overhead for XML search. Practical implications - Overall, the results show the method implemented to support XML search in a traditional IR system such as Okapi is viable. Originality/value - The paper provides useful information on a method for XML indexing based on the IR system Okapi.
-
MacFarlane, A.; McCann, J.A.; Robertson, S.E.: Parallel methods for the generation of partitioned inverted files (2005)
0.01
0.008167865 = product of:
0.01633573 = sum of:
0.01633573 = product of:
0.03267146 = sum of:
0.03267146 = weight(_text_:systems in 651) [ClassicSimilarity], result of:
0.03267146 = score(doc=651,freq=2.0), product of:
0.16037072 = queryWeight, product of:
3.0731742 = idf(docFreq=5561, maxDocs=44218)
0.052184064 = queryNorm
0.2037246 = fieldWeight in 651, product of:
1.4142135 = tf(freq=2.0), with freq of:
2.0 = termFreq=2.0
3.0731742 = idf(docFreq=5561, maxDocs=44218)
0.046875 = fieldNorm(doc=651)
0.5 = coord(1/2)
0.5 = coord(1/2)
- Abstract
- Purpose - The generation of inverted indexes is one of the most computationally intensive activities for information retrieval systems: indexing large multi-gigabyte text databases can take many hours or even days to complete. We examine the generation of partitioned inverted files in order to speed up the process of indexing. Two types of index partitions are investigated: TermId and DocId. Design/methodology/approach - We use standard measures used in parallel computing such as speedup and efficiency to examine the computing results and also the space costs of our trial indexing experiments. Findings - The results from runs on both partitioning methods are compared and contrasted, concluding that DocId is the more efficient method. Practical implications - The practical implications are that the DocId partitioning method would in most circumstances be used for distributing inverted file data in a parallel computer, particularly if indexing speed is the primary consideration. Originality/value - The paper is of value to database administrators who manage large-scale text collections, and who need to use parallel computing to implement their text retrieval services.
