924 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
Closed nominal rewriting and efficiently computable nominal algebra equality
We analyse the relationship between nominal algebra and nominal rewriting,
giving a new and concise presentation of equational deduction in nominal
theories. With some new results, we characterise a subclass of equational
theories for which nominal rewriting provides a complete procedure to check
nominal algebra equality. This subclass includes specifications of the
lambda-calculus and first-order logic.Comment: In Proceedings LFMTP 2010, arXiv:1009.218
Complexity of fuzzy answer set programming under Łukasiewicz semantics
Fuzzy answer set programming (FASP) is a generalization of answer set programming (ASP) in which propositions are allowed to be graded. Little is known about the computational complexity of FASP and almost no techniques are available to compute the answer sets of a FASP program. In this paper, we analyze the computational complexity of FASP under Łukasiewicz semantics. In particular we show that the complexity of the main reasoning tasks is located at the first level of the polynomial hierarchy, even for disjunctive FASP programs for which reasoning is classically located at the second level. Moreover, we show a reduction from reasoning with such FASP programs to bilevel linear programming, thus opening the door to practical applications. For definite FASP programs we can show P-membership. Surprisingly, when allowing disjunctions to occur in the body of rules – a syntactic generalization which does not affect the expressivity of ASP in the classical case – the picture changes drastically. In particular, reasoning tasks are then located at the second level of the polynomial hierarchy, while for simple FASP programs, we can only show that the unique answer set can be found in pseudo-polynomial time. Moreover, the connection to an existing open problem about integer equations suggests that the problem of fully characterizing the complexity of FASP in this more general setting is not likely to have an easy solution
The design with intent method: A design tool for influencing user behaviour
The official published version can be found at the link below.Using product and system design to influence user behaviour offers potential for improving performance and reducing user error, yet little guidance is available at the concept generation stage for design teams briefed with influencing user behaviour. This article presents the Design with Intent Method, an innovation tool for designers working in this area, illustrated via application to an everyday human–technology interaction problem: reducing the likelihood of a customer leaving his or her card in an automatic teller machine. The example application results in a range of feasible design concepts which are comparable to existing developments in ATM design, demonstrating that the method has potential for development and application as part of a user-centred design process
The Common Order-Theoretic Structure of Version Spaces and ATMS\u27s
This paper exposes the common order-theoretic properties of the structures manipulated by the version space algorithm [Mit78]and the assumption-based truth maintenance systems (ATMS) [dk86a,dk86b] by recasting them in the framework of convex spaces. Our analysis of version spaces in this framework reveals necessary and sufficient conditions for ensuring the preservation of an essential finite representability property in version space merging. This analysis is used to formulate several sufficient conditions for when a language will allow version spaces to be represented by finite sets of concepts (even when the universe of concepts may be infinite). We provide a new convex space based formulation of computation performs by an ATMS which extends the expressiveness of disjunctions in the systems. This approach obviates the need for hyper-resolution in dealing with disjunction and results in simpler label-update algorithms
ATMS-Based architecture for stylistics-aware text generation
This thesis is concerned with the effect of surface stylistic constraints (SSC) on syntactic
and lexical choice within a unified generation architecture. Despite the fact that these
issues have been investigated by researchers in the field, little work has been done with
regard to system architectures that allow surface form constraints to influence earlier
linguistic or even semantic decisions made throughout the NLG process. By SSC we
mean those stylistic requirements that are known beforehand but cannot be tested
until after the utterance or — in some lucky cases — until a proper linearised part
of it has been generated. These include collocational constraints, text size limits, and
poetic aspects such as rhyme and metre to name a few.
This thesis introduces a new NLG architecture that can be sensitive to surface stylistic
requirements. It brings together a well-founded linguistic theory that has been used
in many successful NLG systems (Systemic Functional Linguistics, SFL) and an exist¬
ing AI search mechanism (the Assumption-based Truth Maintenance System, ATMS)
which caches important search information and avoids work duplication.
To this end, the thesis explores the logical relation between the grammar formalism and
the search technique. It designs, based on that logical connection, an algorithm for the
automatic translation of systemic grammar networks to ATMS dependency networks.
The generator then uses the translated networks to generate natural language texts
with a high paraphrasing power as a direct result of its ability to pursue multiple paths
simultaneously. The thesis approaches the crucial notion of choice differently to previ¬
ous systems using SFL. It relaxes the choice process in that choosers are not obliged to
deterministically choose a single alternative allowing SSC to influence the final lexical
and syntactic decisions. The thesis also develops a situation-action framework for the
specification of stylistic requirements independently of the micro-semantic input. The
user or application can state what surface requirements they wish to impose and the
ATMS-based generator then attempts to satisfy these constraints.
Finally, a prototype ATMS-based generation system embodying the ideas presented in
this thesis is implemented and evaluated. We examine the system's stylistic sensitivity
by testing it on three different sets of stylistic requirements, namely: collocational,
size, and poetic constraints
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Working notes of the 1991 spring symposium on constraint-based reasoning
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