27,517 research outputs found
Recommended from our members
Learning from AI : new trends in database technology
Recently some researchers in the areas of database data modelling and knowledge representations in artificial intelligence have recognized that they share many common goals. In this survey paper we show the relationship between database and artificial intelligence research. We show that there has been a tendency for data models to incorporate more modelling techniques developed for knowledge representations in artificial intelligence as the desire to incorporate more application oriented semantics, user friendliness, and flexibility has increased. Increasing the semantics of the representation is the key to capturing the "reality" of the database environment, increasing user friendliness, and facilitating the support of multiple, possibly conflicting, user views of the information contained in a database
A Call to Arms: Revisiting Database Design
Good database design is crucial to obtain a sound, consistent database, and -
in turn - good database design methodologies are the best way to achieve the
right design. These methodologies are taught to most Computer Science
undergraduates, as part of any Introduction to Database class. They can be
considered part of the "canon", and indeed, the overall approach to database
design has been unchanged for years. Moreover, none of the major database
research assessments identify database design as a strategic research
direction.
Should we conclude that database design is a solved problem?
Our thesis is that database design remains a critical unsolved problem.
Hence, it should be the subject of more research. Our starting point is the
observation that traditional database design is not used in practice - and if
it were used it would result in designs that are not well adapted to current
environments. In short, database design has failed to keep up with the times.
In this paper, we put forth arguments to support our viewpoint, analyze the
root causes of this situation and suggest some avenues of research.Comment: Removed spurious column break. Nothing else was change
On relating CTL to Datalog
CTL is the dominant temporal specification language in practice mainly due to
the fact that it admits model checking in linear time. Logic programming and
the database query language Datalog are often used as an implementation
platform for logic languages. In this paper we present the exact relation
between CTL and Datalog and moreover we build on this relation and known
efficient algorithms for CTL to obtain efficient algorithms for fragments of
stratified Datalog. The contributions of this paper are: a) We embed CTL into
STD which is a proper fragment of stratified Datalog. Moreover we show that STD
expresses exactly CTL -- we prove that by embedding STD into CTL. Both
embeddings are linear. b) CTL can also be embedded to fragments of Datalog
without negation. We define a fragment of Datalog with the successor build-in
predicate that we call TDS and we embed CTL into TDS in linear time. We build
on the above relations to answer open problems of stratified Datalog. We prove
that query evaluation is linear and that containment and satisfiability
problems are both decidable. The results presented in this paper are the first
for fragments of stratified Datalog that are more general than those containing
only unary EDBs.Comment: 34 pages, 1 figure (file .eps
Neurally Implementable Semantic Networks
We propose general principles for semantic networks allowing them to be
implemented as dynamical neural networks. Major features of our scheme include:
(a) the interpretation that each node in a network stands for a bound
integration of the meanings of all nodes and external events the node links
with; (b) the systematic use of nodes that stand for categories or types, with
separate nodes for instances of these types; (c) an implementation of
relationships that does not use intrinsically typed links between nodes.Comment: 32 pages, 12 figure
Challenges in Bridging Social Semantics and Formal Semantics on the Web
This paper describes several results of Wimmics, a research lab which names
stands for: web-instrumented man-machine interactions, communities, and
semantics. The approaches introduced here rely on graph-oriented knowledge
representation, reasoning and operationalization to model and support actors,
actions and interactions in web-based epistemic communities. The re-search
results are applied to support and foster interactions in online communities
and manage their resources
From Frequency to Meaning: Vector Space Models of Semantics
Computers understand very little of the meaning of human language. This
profoundly limits our ability to give instructions to computers, the ability of
computers to explain their actions to us, and the ability of computers to
analyse and process text. Vector space models (VSMs) of semantics are beginning
to address these limits. This paper surveys the use of VSMs for semantic
processing of text. We organize the literature on VSMs according to the
structure of the matrix in a VSM. There are currently three broad classes of
VSMs, based on term-document, word-context, and pair-pattern matrices, yielding
three classes of applications. We survey a broad range of applications in these
three categories and we take a detailed look at a specific open source project
in each category. Our goal in this survey is to show the breadth of
applications of VSMs for semantics, to provide a new perspective on VSMs for
those who are already familiar with the area, and to provide pointers into the
literature for those who are less familiar with the field
Automated schema matching techniques: an exploratory study
Manual schema matching is a problem for many database applications that use multiple data sources including data warehousing and e-commerce applications. Current research attempts to address this problem by developing algorithms to automate aspects of the schema-matching task. In this paper, an approach using an external dictionary facilitates automated discovery of the semantic meaning of database schema terms. An experimental study was conducted to evaluate the performance and accuracy of five schema-matching techniques with the proposed approach, called SemMA. The proposed approach and results are compared with two existing semi-automated schema-matching approaches and suggestions for future research are made
Indicative Conditionals and Dynamic Epistemic Logic
Recent ideas about epistemic modals and indicative conditionals in formal
semantics have significant overlap with ideas in modal logic and dynamic
epistemic logic. The purpose of this paper is to show how greater interaction
between formal semantics and dynamic epistemic logic in this area can be of
mutual benefit. In one direction, we show how concepts and tools from modal
logic and dynamic epistemic logic can be used to give a simple, complete
axiomatization of Yalcin's [16] semantic consequence relation for a language
with epistemic modals and indicative conditionals. In the other direction, the
formal semantics for indicative conditionals due to Kolodny and MacFarlane [9]
gives rise to a new dynamic operator that is very natural from the point of
view of dynamic epistemic logic, allowing succinct expression of dependence (as
in dependence logic) or supervenience statements. We prove decidability for the
logic with epistemic modals and Kolodny and MacFarlane's indicative conditional
via a full and faithful computable translation from their logic to the modal
logic K45.Comment: In Proceedings TARK 2017, arXiv:1707.0825
- …