3,788 research outputs found
Reason Maintenance - State of the Art
This paper describes state of the art in reason maintenance with a focus on its future usage in the KiWi project. To give a bigger picture of the field, it also mentions closely related issues such as non-monotonic logic and paraconsistency. The paper is organized as follows: first, two motivating scenarios referring to semantic wikis are presented which are then used to introduce the different reason maintenance techniques
The Use of Dependency Relationships in the Control of Reasoning
Research reported herein was conducted at the Artificial Intelligence Laboratory, a Massachusetts Institute of Technology research program supported in part by the Advanced Research Projects Agency of the Department of Defense and monitored by the Office of Naval Research under contract N00014-75-C-0643.Several recent problem-solving programs have indicated improved methods for controlling program actions. Some of these methods operate by analyzing the time-independent antecedent-consequent dependency relationships between the components of knowledge about the problem for solution. This paper is a revised version of a thesis proposal which indicates how a general system of automatically maintained dependency relationships can be used to effect many forms of control on reasoning in an antecedent reasoning framework.MIT Artificial Intelligence Laboratory
Department of Defense Advanced Research Projects Agenc
Database repairs with answer set programming
Dissertação para obtenção do Grau de Mestre em
Engenharia InformáticaIntegrity constraints play an important part in database design. They are what allow
databases to store accurate information, since they impose some properties that must
always hold. However, none of the existing Database Management Systems allows the
specification of new integrity constraints if the information stored is already violating
these new integrity constraints.
In this dissertation, we developed DRSys, an application that allows the user to specify
integrity constraints that he wishes to enforce in the database. If the database becomes
inconsistent with respect to such integrity constraints, DRSys returns to the user possible ways to restore consistency, by inserting or deleting tuples into/from the original database, creating a new consistent database, a database repair. Also, since we are dealing with databases, we want to change as little information as possible, so DRSys offers the user two distinct minimality criteria when repairing the database: minimality under set inclusion or minimality under cardinality of operations.
We approached the database repairing problem by using the capacity of problem solving
offered by Answer Set Programming (ASP), which benefits from the simple specification
of problems, and the existence of “Solvers” that solve those problems in an efficient
manner.
DRSys is a database repair application that was built on top of the database management
system PostgreSQL. Furthermore, we developed a graphical user interface, to aid
the user in the whole process of defining new integrity constraints and in the process of database repairing.
We evaluate the performance and scalability of DRSys, by presenting several tests in
different situations, exploring particular features of it as well, in order to understand the scalability of DRSys
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