17,001 research outputs found
Temporal Data Modeling and Reasoning for Information Systems
Temporal knowledge representation and reasoning is a major research field in Artificial
Intelligence, in Database Systems, and in Web and Semantic Web research. The ability to
model and process time and calendar data is essential for many applications like appointment
scheduling, planning, Web services, temporal and active database systems, adaptive
Web applications, and mobile computing applications. This article aims at three complementary
goals. First, to provide with a general background in temporal data modeling
and reasoning approaches. Second, to serve as an orientation guide for further specific
reading. Third, to point to new application fields and research perspectives on temporal
knowledge representation and reasoning in the Web and Semantic Web
A Reasoner for Calendric and Temporal Data
Calendric and temporal data are omnipresent in countless
Web and Semantic Web applications and Web services. Calendric and
temporal data are probably more than any other data a subject to
interpretation, in almost any case depending on some cultural, legal,
professional, and/or locational context. On the current Web, calendric
and temporal data can hardly be interpreted by computers. This article
contributes to the Semantic Web, an endeavor aiming at enhancing
the current Web with well-defined meaning and to enable computers to
meaningfully process data. The contribution is a reasoner for calendric
and temporal data. This reasoner is part of CaTTS, a type language for
calendar definitions. The reasoner is based on a \theory reasoning" approach
using constraint solving techniques. This reasoner complements
general purpose \axiomatic reasoning" approaches for the Semantic Web
as widely used with ontology languages like OWL or RDF
Calendar.help: Designing a Workflow-Based Scheduling Agent with Humans in the Loop
Although information workers may complain about meetings, they are an
essential part of their work life. Consequently, busy people spend a
significant amount of time scheduling meetings. We present Calendar.help, a
system that provides fast, efficient scheduling through structured workflows.
Users interact with the system via email, delegating their scheduling needs to
the system as if it were a human personal assistant. Common scheduling
scenarios are broken down using well-defined workflows and completed as a
series of microtasks that are automated when possible and executed by a human
otherwise. Unusual scenarios fall back to a trained human assistant who
executes them as unstructured macrotasks. We describe the iterative approach we
used to develop Calendar.help, and share the lessons learned from scheduling
thousands of meetings during a year of real-world deployments. Our findings
provide insight into how complex information tasks can be broken down into
repeatable components that can be executed efficiently to improve productivity.Comment: 10 page
A Reasoner for Calendric and Temporal Data
Calendric and temporal data are omnipresent in countless
Web and Semantic Web applications and Web services. Calendric and
temporal data are probably more than any other data a subject to
interpretation, in almost any case depending on some cultural, legal,
professional, and/or locational context. On the current Web, calendric
and temporal data can hardly be interpreted by computers. This article
contributes to the Semantic Web, an endeavor aiming at enhancing
the current Web with well-defined meaning and to enable computers to
meaningfully process data. The contribution is a reasoner for calendric
and temporal data. This reasoner is part of CaTTS, a type language for
calendar definitions. The reasoner is based on a "theory reasoning" approach
using constraint solving techniques. This reasoner complements
general purpose "axiomatic reasoning" approaches for the Semantic Web
as widely used with ontology languages like OWL or RDF
Temporalized logics and automata for time granularity
Suitable extensions of the monadic second-order theory of k successors have
been proposed in the literature to capture the notion of time granularity. In
this paper, we provide the monadic second-order theories of downward unbounded
layered structures, which are infinitely refinable structures consisting of a
coarsest domain and an infinite number of finer and finer domains, and of
upward unbounded layered structures, which consist of a finest domain and an
infinite number of coarser and coarser domains, with expressively complete and
elementarily decidable temporal logic counterparts.
We obtain such a result in two steps. First, we define a new class of
combined automata, called temporalized automata, which can be proved to be the
automata-theoretic counterpart of temporalized logics, and show that relevant
properties, such as closure under Boolean operations, decidability, and
expressive equivalence with respect to temporal logics, transfer from component
automata to temporalized ones. Then, we exploit the correspondence between
temporalized logics and automata to reduce the task of finding the temporal
logic counterparts of the given theories of time granularity to the easier one
of finding temporalized automata counterparts of them.Comment: Journal: Theory and Practice of Logic Programming Journal Acronym:
TPLP Category: Paper for Special Issue (Verification and Computational Logic)
Submitted: 18 March 2002, revised: 14 Januari 2003, accepted: 5 September
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A Type Language for Calendars
Time and calendars play an important role in databases,
on the Semantic Web, as well as in mobile computing. Temporal data
and calendars require (specific) modeling and processing tools. CaTTS
is a type language for calendar definitions using which one can model
and process temporal and calendric data. CaTTS is based on a "theory
reasoning" approach for efficiency reasons. This article addresses type
checking temporal and calendric data and constraints. A thesis underlying
CaTTS is that types and type checking are as useful and desirable
with calendric data types as with other data types. Types enable
(meaningful) annotation of data. Type checking enhances efficiency and
consistency of programming and modeling languages like database and
Web query languages
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
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Reading "all about" computerization: five common genres of social analysis
This paper examines unstated, but critical, social assumptions which underlie analyses of computerization. It focuses on the popular, professional and scholarly literature which claims to describe the actual nature of computerization, the character of computer use, and the social choices and changes that result from computerization. This literature can be usefully segmented five ideal type genres: utopian, anti-utopian, social realism, social theory, and analytical reduction. Each genre is characterized and illustrated. The strengths and weaknesses of each genre are described. In the 1990s, there will be a large market for social analyses of computerization. Utopian analyses are most likely to domínate the popular and professional discourse. The empirically oriented accounts of social realism, social theory and analytical reduction, are likely to be much less common and also less commonly seen and read by computer professionals and policymakers. These genres are relatively subtle, portray a more ambiguous world, and have less rhetorical power to capture the imagination of readers. Even though they are more scientific, these empirically anchored genres don't seem to appeal to many scientists and engineers. It is ironic that computing -- often portrayed as an instrument of knowledge -- is primarily the subject of discourses whose knowledge claims are most suspect. Conversely, the discourses whose claims as valid knowledge are strongest seems to have much less appeal in the mass media and technological communities
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Proceedings ICPW'07: 2nd International Conference on the Pragmatic Web, 22-23 Oct. 2007, Tilburg: NL
Proceedings ICPW'07: 2nd International Conference on the Pragmatic Web, 22-23 Oct. 2007, Tilburg: N
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