447 research outputs found
Distributed Model-Based Diagnosis using Object-Relational Constraint Databases
This work presents a proposal to diagnose distributed
systems utilizing model-based diagnosis using distributed
databases. In order to improve aspects as versatility, persistence,
easy composition and efficiency in the diagnosis
process we use an Object Relational Constraint Database
(ORCDB). Thereby we define a distributed architecture to
store the behaviour of components as constraints in a relational
database to diagnose a distributed system. This
work proposes an algorithm to detect which components fail
when their information is distributed in several databases,
and all the information is not available in a global way. It
is also offered a proposal to define, in execution time, the
allocation of the sensors in a distributed system.Ministerio de Ciencia y Tecnología DPI2003-07146-C02-0
Constraint Databases and Geographic Information Systems
Constraint databases and geographic information systems share many applications. However, constraint databases can go beyond geographic information systems in efficient
spatial and spatiotemporal data handling methods and in advanced applications. This survey mainly describes ways that constraint databases go beyond geographic information systems. However, the survey points out that in some areas constraint databases can learn also from geographic information systems
Applying Constraint Databases in the Determination of Potential Minimal Conflicts to Polynomial Model-Based Diagnosis
Model-based Diagnosis allows the identification of the parts
which fail in a system. The models are based on the knowledge of the
system to diagnose, and may be represented by constraints associated
to the components. The variables of these constraints can be observable
or non-observable, depending on the situation of the sensors. In order to
obtain the potential minimal diagnosis in a system, an important issue is
related to finding out the potential minimal conflicts in an efficient way.
We consider that Constraint Databases represent an excellent option in
order to solve this problem in complex systems.
In this work we have used a novel logical architecture of Constraint
Databases which has allowed obtaining these potential conflicts by means
of the corresponding queries. Moreover, we have considered Gröbner
Bases as a projection operator to obtain the potential minimal conflicts
of a system. The first results obtained on this work, which are shown in
a heat exchangers example, have been very promising.Ministerio de Ciencia y Tecnología DPI2003-07146-C02-0
Constraint Databases Technology for Polynomial Models Diagnosis
Model-based Diagnosis allows the identification of the
parts which fail in a system. The models are based on the knowledge
of the system to diagnose, and they can be represented by constraints
associated to the components. The variables including in these con straints can be observable or non-observable, depending on the situa tion of sensors. In order to obtain the minimal diagnosis in a system,
an important issue is related to find out the minimal possible conflicts
in an efficient way. We consider that Constraint Databases represent
an excellent approach in order to solve this problem in complex sys tems, where a tuple in a relational database could be replaced by a
conjunction of constraints.
In this work we have used a novel logical architecture of Con straint Databases which has allowed us to obtain these possible min imal conflicts by means of a standard query language though the in formation is stored in a conventional relational database. Moreover,
we have considered Grobner bases as a projection operator to obtain ¨
the minimal possible conflicts of a system.Ministerio de Ciencia y Tecnología DPI2003-07146-C02-0
Efficient evaluation of specific queries in constraint databases
Let F1,...,FsεR[X1,...,Xn] be polynomials of degree at most d, and suppose that F1,...,F s are represented by a division free arithmetic circuit of non-scalar complexity size L. Let A be the arrangement of Rn defined by F 1,...,Fs. For any point xεRn, we consider the task of determining the signs of the values F1(x),...,F s(x) (sign condition query) and the task of determining the connected component of A to which x belongs (point location query). By an extremely simple reduction to the well-known case where the polynomials F 1,...,Fs are affine linear (i.e., polynomials of degree one), we show first that there exists a database of (possibly enormous) size sO(L+n) which allows the evaluation of the sign condition query using only (Ln)O(1)log(s) arithmetic operations. The key point of this paper is the proof that this upper bound is almost optimal. By the way, we show that the point location query can be evaluated using dO(n)log(s) arithmetic operations. Based on a different argument, analogous complexity upper-bounds are exhibited with respect to the bit-model in case that F 1,...,Fs belong to Z[X1,...,Xn] and satisfy a certain natural genericity condition. Mutatis mutandis our upper-bound results may be applied to the sparse and dense representations of F 1,...,Fs.Fil: Grimson, Rafael. Hasselt University; Bélgica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria; ArgentinaFil: Heintz, Joos Ulrich. Universidad de Cantabria; España. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Computación; ArgentinaFil: Kuijpers, Bart. Hasselt University; Bélgic
A-Maze-D: Advanced Maze Development Kit Using Constraint Databases
In this paper, we describe the A-Maze-D system which shows that constraint databases can be applied conveniently and efficiently to the design of maze games. A-Maze-D provides a versatile set of features by a combination of a MATLAB library and the MLPQ constraint database system. A-Maze-D is the first system that uses constraint databases to build maze games and opens new ideas in video game development
Developing a labelled object-relational constraint database architecture for the projection operator
Current relational databases have been developed in order to improve the handling of
stored data, however, there are some types of information that have to be analysed for
which no suitable tools are available. These new types of data can be represented and treated
as constraints, allowing a set of data to be represented through equations, inequations
and Boolean combinations of both. To this end, constraint databases were defined and
some prototypes were developed. Since there are aspects that can be improved, we propose
a new architecture called labelled object-relational constraint database (LORCDB). This provides
more expressiveness, since the database is adapted in order to support more types of
data, instead of the data having to be adapted to the database. In this paper, the projection
operator of SQL is extended so that it works with linear and polynomial constraints and
variables of constraints. In order to optimize query evaluation efficiency, some strategies
and algorithms have been used to obtain an efficient query plan.
Most work on constraint databases uses spatiotemporal data as case studies. However,
this paper proposes model-based diagnosis since it is a highly potential research area,
and model-based diagnosis permits more complicated queries than spatiotemporal examples.
Our architecture permits the queries over constraints to be defined over different sets
of variables by using symbolic substitution and elimination of variables.Ministerio de Ciencia y Tecnología DPI2006-15476-C02-0
Querying a Polynomial Object-Relational Constraint Database in Model-Based Diagnosis
Many papers related to Constraint Databases (CDBs) theories
exist, including proposals that present frameworks for the treatment
of constraints as a new data type. Our proposal presents a new way
of storing and manipulating constraints as a usual data, and of making
queries about the constraint variables derived from an Object-Relational
Constraint Database (ORCDB). In this work, the constraints stored in
an ORCDB are only polynomial equality constraints. The proposal is
based on Gr¨obner bases, constraint consistency and constraint optimisation
techniques. Most works in CDB use spatial-temporal data as a case
study, however this work presents an emergent engineering domain, that
of fault diagnosis.Ministerio de Ciencia y Tecnología DPI2003-07146-C02-0
07212 Abstracts Collection -- Constraint Databases, Geometric Elimination ang Geographic Information Systems
From 20.05. to 25.05., the Dagstuhl Seminar 07212 ``Constraint Databases, Geometric Elimination and Geographic Information Systems\u27\u27 was held
in the International Conference and Research Center (IBFI),
Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
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