Applying knowledge compilation techniques to model-based reasoning

Researchers in the area of knowledge compilation are developing general purpose techniques for improving the efficiency of knowledge-based systems. In this article, an attempt is made to define knowledge compilation, to characterize several classes of knowledge compilation techniques, and to illustrate how some of these techniques can be applied to improve the performance of model-based reasoning systems

Linguistics in the Study and Teaching of Literature

Literary texts include linguistic form, as well as specialized literary forms (some of which also involve language). Linguistics can offer to literary studies an understanding of these kinds of form, and the ways by which a text is used to communicate meaning. In order to cope with the great variety of creative uses of language in literature, linguistics must acknowledge that some texts are assigned structure by non-linguistic means, but the boundaries between linguistic and non-linguistic explanations for literary language are not clearly drawn. The article concludes with discussion of what kinds and level of linguistics might usefully be taught in a literature classroom, and offers practical suggestions for the application of linguistics to literature teaching

Phenomenological High Precision Neutron-Proton Delta-Shell Potential

We provide a successful fit for proton-neutron scattering below pion production threshold up to LAB energies of 350 MeV. We use seven high-quality fits based on potentials with different forms as a measure of the systematic uncertainty. We represent the interaction as a sum of delta-shells in configuration space below the 3fm and a charge dependent one pion exchange potential above 3fm together with magnetic and vacuum polarization effects. Special attention is paid to estimate the errors of the phenomenological interaction.Comment: 5 pages, 2 figures. Comments and one figure with differential observables adde

In defense of compilation: A response to Davis' form and content in model-based reasoning

In a recent paper entitled 'Form and Content in Model Based Reasoning', Randy Davis argues that model based reasoning research aimed at compiling task specific rules from underlying device models is mislabeled, misguided, and diversionary. Some of Davis' claims are examined and his basic conclusions are challenged about the value of compilation research to the model based reasoning community. In particular, Davis' claim is refuted that model based reasoning is exempt from the efficiency benefits provided by knowledge compilation techniques. In addition, several misconceptions are clarified about the role of representational form in compilation. It is concluded that techniques have the potential to make a substantial contribution to solving tractability problems in model based reasoning

Chomskyan Arguments Against Truth-Conditional Semantics Based on Variability and Co-predication

In this paper I try to show that semantics can explain word-to-world relations and that sentences can have meanings that determine truth-conditions. Critics like Chomsky typically maintain that only speakers denote, i.e., only speakers, by using words in one way or another, represent entities or events in the world. However, according to their view, individual acts of denotations are not explained just by virtue of speakers’ semantic knowledge. Against this view, I will hold that, in the typical cases considered, semantic knowledge can account for the denotational uses of words of individual speakers

MonetDB/XQuery: a fast XQuery processor powered by a relational engine

Relational XQuery systems try to re-use mature relational data management infrastructures to create fast and scalable XML database technology. This paper describes the main features, key contributions, and lessons learned while implementing such a system. Its architecture consists of (i) a range-based encoding of XML documents into relational tables, (ii) a compilation technique that translates XQuery into a basic relational algebra, (iii) a restricted (order) property-aware peephole relational query optimization strategy, and (iv) a mapping from XML update statements into relational updates. Thus, this system implements all essential XML database functionalities (rather than a single feature) such that we can learn from the full consequences of our architectural decisions. While implementing this system, we had to extend the state-of-the-art with a number of new technical contributions, such as loop-lifted staircase join and efficient relational query evaluation strategies for XQuery theta-joins with existential semantics. These contributions as well as the architectural lessons learned are also deemed valuable for other relational back-end engines. The performance and scalability of the resulting system is evaluated on the XMark benchmark up to data sizes of 11GB. The performance section also provides an extensive benchmark comparison of all major XMark results published previously, which confirm that the goal of purely relational XQuery processing, namely speed and scalability, was met

EXTEND-L : an input language for extensible register transfer compilation

This report discusses the model and input language for EXTEND, a synthesis system that permits extensible register transfer synthesis. EXTEND-L fills the need for a language that bridges the gap between existing behavioral input descriptions, which are too abstract, and structural schematics, which cannot capture the high-level behavior. The report first discusses previous work in behavioral synthesis and summarizes the deficiencies of these behavioral specifications. The report then describes the proposed langauge in detail, and concludes with a few examples that show its utility