Some flexible information retrieval systems using structure matching procedures

Salton, Gerard; Sussenguth, Edward H.

doi:10.1145/1464122.1464178

Cited by 10 publications

(6 citation statements)

References 8 publications

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“…It would be very instructive to compare the performance of our algorithm with that of the partitioning procedures [2][3][4]. However, since we could not produce proper time estimates, and since there are no such estimates for the partitioning methods, no real basis for comparison exists.…”

Section: Discussionmentioning

confidence: 99%

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A Backtrack Procedure for Isomorphism of Directed Graphs

Berztiss

1973

J. ACM

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A reasonably efficient procedure for testing pairs of directed graphs for isomorphism is important in information retrieval and other application fields in which structured data have to be matched. One such procedure, a backtrack procedure based on a representation of directed graphs by linear formulas, is described. A procedure for finding a partial subdigraph of a digraph that is isomorphic to a given digraph is also described.KEY WORDS AND PHRASES: backtrack programming, digraph isomorphism, representation of digraphs CR CATEGOnI~S: 5.32 DefinitionsA directed graph or digraph is the ordered pair D = (A, P}, where A is a set and P is a relation in A. We shall assume that A is finite, and put A = {aj, a2, • • •, a~}. Members of A are cMled nodes; members of P are arcs of the digraph. Arc (a~, aj} is said to originate from node a~ and to terminate at node ai. An are (ai, al} is called a sling. Digraph Dis completely specified by its adjace~cy matrix X, which is a square matrix of order n, defined as follows: xlj = 1 if ~al,as} E P, x~i= 0 if (at,as} ¢~ P.A digraph is total if every element of its adjacency matrix is 1.In digraph (A, P}, if certain members of P can be placed in a sequence (al, as}, (as, ak}, • • • , (as, at}, in which the first coordinate of each ordered pair is equal to the second coordinate of its predecessor in the sequence, then at is reachable from a~, and the set of arcs in the sequence is a path from a~ to at. Write the path as a node sequence (a~, as, ak, • .. , as, at). If this node sequence contains every node of the digraph exactly once, then the path is Hamiltonian; addition of arc tat, a~} to the Hamiltonian path gives a Hamiltonian cycle. We assume that every node is reachable from itself. If no arc originates from or terminates at a~, then a~ is an isolated node. The smallest set of nodes from which all nodes of a digraph are reachable is a node base of the digraph. A node base need not be unique, but all node bases of the one digraph contain the same number of nodes.If D = (A, P} is a digraph, and B is a subset of A, then D' = (B, (B X B) A P} is a subdigraph of D. If Q is a subset of P, .then D" = (A, Q} is a partial digraph of D.The concept of a partial subdigraph is an obvious extension.Two digraphs are isomorphic if some permutation of the rows and corresponding

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Section: Discussionmentioning

confidence: 99%

“…Going to Table B, one finds that B(4) = 1, B(5) = 3, B(6) = 4, B(7) = 6, and that B (8) is a null entry, i.e. the tables tell that the arcs originating from node 2 are <2, 1>, <2, 3), (2,4), and <2, 6>. L (4) = 0 tells one that no arcs originate from node 4.…”

Section: Impiemenlalion Of the Backt'rac/~ Proceduresmentioning

confidence: 99%

A Backtrack Procedure for Isomorphism of Directed Graphs

Berztiss

1973

J. ACM

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“…The matrix representing the sample criterion phi-ase is similarly shown in Figuie ti(e). In the SMART system a graphmatching process uses the matrices to detect matching phrases [4].…”

Section: Tj'pical Data Representationsmentioning

confidence: 99%

Data manipulation and programming problems in automatic information retrieval

Salton

1966

Commun. ACM

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Automatic information retrieval programs require the manipulation of a variety of different data structures, including linear text, sparse matrices, and tree or list structures. The main data manipulations to be performed in automatic information systems are first briefly reviewed. A variety of data representations which have been used to describe structured Information are then examined, and the characteristics of various processing languages are outlined in the light of the procedures requiring implementation. Advantages and disadvantages of these programming languages for the retrieval application are examined, and suggestions are made for the design of programming facilities to aid in information retrieval.

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“…Nodes from the graph describing the query substructure then need to be considered for matching only against those nodes from a database structure that possess the same characteristics. It is interesting to note that this work was carried out in collaboration with Gerard Salton, as part of his pioneering work on statistical methods for retrieval that laid the foundation for present-day information retrieval systems [79]. The idea of linking query nodes to database nodes is fundamental to all substructure searching algorithms, including the refinement procedure that lies at the heart of the subgraph isomorphism algorithm due to Ullmann [56].…”

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confidence: 99%

From chemical documentation to chemoinformatics: 50 years of chemical information science

Willett

2008

Journal of Information Science

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This paper summarises the historical development of the discipline that is now called 'chemoinformatics'. It shows how this has evolved, principally as a result of technological developments in chemistry and biology during the past decade, from long-established techniques for the modelling and searching of chemical molecules. A total of 30 papers, the earliest dating back to 1957, are briefly summarised to highlight some of the key publications and to show the development of the discipline.Keywords: Chemical documentation; Chemical structures; Chemoinformatics; Drug discovery; History; Informatics; Molecules; Pharmaceutical research IntroductionChemistry is, and has been for many years, one of the most information-rich academic disciplines. The very first journal devoted to chemistry was Chemisches Journal, which was published 1778-1784 and then, under the name of Chemische Annalen, till 1803 [1]. The growth in the chemical literature during the 19 th century led to a recognition of the need for comprehensive abstracting and indexing services for the chemical sciences. The principal such service is Chemical Abstracts Service (CAS), which was established in 1907 and which acts as the central repository for the world's published chemical (and, increasingly, life-sciences) information. The size of this repository is impressive: at the end of its first year of operations, the CAS database contained ca. 12K abstracts; by the end of 2006, this had grown to ca. 25M abstracts with ca. 1M being added each year. Most chemical publications will refer to one or more chemical substances. The structures of these substances form a vitally important part of the chemical literature, and one that distinguishes chemistry from many other disciplines. The CAS Registry System was started in 1965 to provide access to substance information, initially registering just small organic and inorganic molecules but now also registering biological sequences [2]. At the end of 1965 there 1 Correspondence to: Prof. Peter Willett, Department of Information Studies, University of Sheffield, 211 Portobello Street, Sheffield S1 4DP, UK; p.willett@sheffield.ac.uk. Journal of Information Science, XX (X) 2007, pp. 1-24 © CILIP, DOI: 10.1177/0165551506nnnnnn 1 Peter Willettwere ca. 222K substances in the System; by the end of 2006 this had grown to ca. 89M substances, of which ca. one-third were small molecules and the remainder biological sequences, with ca. 1.5M being added each year. There are also many additional molecular structures in public databases such as the Beilstein Database [3], and corporate files, in particular those of the major pharmaceutical, agrochemical and biotechnology companies.The presence of chemical structures requires very different computational techniques from those used for processing conventional textual information. These specialised techniques -now referred to by the name of chemoinformatics as discussed further below -have developed steadily over the fifty years that have passed since the founding of the I...

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Some flexible information retrieval systems using structure matching procedures

Cited by 10 publications

References 8 publications

A Backtrack Procedure for Isomorphism of Directed Graphs

A Backtrack Procedure for Isomorphism of Directed Graphs

Data manipulation and programming problems in automatic information retrieval

From chemical documentation to chemoinformatics: 50 years of chemical information science

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