3,865 research outputs found
The Role of Indexing in Subject Retrieval
On first reading the list of speakers proposed for this institute, I
became aware of being rather the "odd man out" for two reasons. Firstly, I
was asked to present a paper on PRECIS which is very much a verbal
indexing system-at a conference dominated by contributions on classification
schemes with a natural bias, as the centenary year approaches, toward the
Dewey Decimal Classification (DDC). Secondly, I feared (quite wrongly, as it
happens) that I might be at variance with one or two of my fellow speakers,
who would possibly like to assure us, in an age when we can no longer ignore
the computer, that traditional library schemes such as DDC and Library of
Congress Classification (LCC) are capable of maintaining their original
function of organizing collections of documents, and at the same time are also
well suited to the retrieval of relevant citations from machine-held files. In
this context, I am reminded of a review of a general collection of essays on
classification schemes which appeared in the Journal of Documentation in
1972. Norman Roberts, reviewing the papers which dealt specifically with the
well established schemes, deduced that "all the writers project their particular
schemes into the future with an optimism that springs, perhaps, as much from
a sense of emotional involvement as from concrete evidence." Since I do not
believe that these general schemes can play any significant part in the retrieval
of items from mechanized files, it appeared that I had been cast in the role of
devil's advocate.published or submitted for publicatio
Adding Logical Operators to Tree Pattern Queries on Graph-Structured Data
As data are increasingly modeled as graphs for expressing complex
relationships, the tree pattern query on graph-structured data becomes an
important type of queries in real-world applications. Most practical query
languages, such as XQuery and SPARQL, support logical expressions using
logical-AND/OR/NOT operators to define structural constraints of tree patterns.
In this paper, (1) we propose generalized tree pattern queries (GTPQs) over
graph-structured data, which fully support propositional logic of structural
constraints. (2) We make a thorough study of fundamental problems including
satisfiability, containment and minimization, and analyze the computational
complexity and the decision procedures of these problems. (3) We propose a
compact graph representation of intermediate results and a pruning approach to
reduce the size of intermediate results and the number of join operations --
two factors that often impair the efficiency of traditional algorithms for
evaluating tree pattern queries. (4) We present an efficient algorithm for
evaluating GTPQs using 3-hop as the underlying reachability index. (5)
Experiments on both real-life and synthetic data sets demonstrate the
effectiveness and efficiency of our algorithm, from several times to orders of
magnitude faster than state-of-the-art algorithms in terms of evaluation time,
even for traditional tree pattern queries with only conjunctive operations.Comment: 16 page
Recommended from our members
The Learning Grid and E-Assessment using Latent Semantic Analysis
E-assessment is an important component of e-learning and e-qualification. Formative and summative assessment serve different purposes and both types of evaluation are critical to the pedagogicalprocess. While students are studying, practicing, working, or revising, formative assessment provides direction, focus, and guidance. Summative assessment provides the means to evaluate a learner's achievement and communicate that achievement to interested parties. Latent Semantic Analysis (LSA) is a statistical method for inferring meaning from a text. Applications based on LSA exist that provide both summative and formative assessment of a learner's work. However, the huge computational needs are a major problem with this promising technique. This paper explains how LSA works, describes the breadth of existing applications using LSA, explains how LSA is particularly suited to e-assessment, and proposes research to exploit the potential computational power of the Grid to overcome one of LSA's drawbacks
Proceedings of the Workshop Semantic Content Acquisition and Representation (SCAR) 2007
This is the proceedings of the Workshop on Semantic Content Acquisition and Representation, held in conjunction with NODALIDA 2007, on May 24 2007 in Tartu, Estonia.</p
Software Citation Implementation Challenges
The main output of the FORCE11 Software Citation working group
(https://www.force11.org/group/software-citation-working-group) was a paper on
software citation principles (https://doi.org/10.7717/peerj-cs.86) published in
September 2016. This paper laid out a set of six high-level principles for
software citation (importance, credit and attribution, unique identification,
persistence, accessibility, and specificity) and discussed how they could be
used to implement software citation in the scholarly community. In a series of
talks and other activities, we have promoted software citation using these
increasingly accepted principles. At the time the initial paper was published,
we also provided guidance and examples on how to make software citable, though
we now realize there are unresolved problems with that guidance. The purpose of
this document is to provide an explanation of current issues impacting
scholarly attribution of research software, organize updated implementation
guidance, and identify where best practices and solutions are still needed
Dynamics, robustness and fragility of trust
Trust is often conveyed through delegation, or through recommendation. This
makes the trust authorities, who process and publish trust recommendations,
into an attractive target for attacks and spoofing. In some recent empiric
studies, this was shown to lead to a remarkable phenomenon of *adverse
selection*: a greater percentage of unreliable or malicious web merchants were
found among those with certain types of trust certificates, then among those
without. While such findings can be attributed to a lack of diligence in trust
authorities, or even to conflicts of interest, our analysis of trust dynamics
suggests that public trust networks would probably remain vulnerable even if
trust authorities were perfectly diligent. The reason is that the process of
trust building, if trust is not breached too often, naturally leads to
power-law distributions: the rich get richer, the trusted attract more trust.
The evolutionary processes with such distributions, ubiquitous in nature, are
known to be robust with respect to random failures, but vulnerable to adaptive
attacks. We recommend some ways to decrease the vulnerability of trust
building, and suggest some ideas for exploration.Comment: 17 pages; simplified the statement and the proof of the main theorem;
FAST 200
Expressing the GIVE event in Papuan languages: A preliminary survey
The linguistic expression of the GIVE event is investigated in a sample of 72 Papuan languages, 33 belonging to the Trans New Guinea family, 39 of various non-TNG lineages. Irrespective of the verbal template (prefix, suffix, or no indexation of undergoer), in the majority of languages the recipient is marked as the direct object of a monotransitive verb, which sometimes involves stem suppletion for the recipient. While a few languages allow verbal affixation for all three arguments, a number of languages challenge the universal claim that the `give' verb always has three arguments
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