203 research outputs found
Propagators and Solvers for the Algebra of Modular Systems
To appear in the proceedings of LPAR 21.
Solving complex problems can involve non-trivial combinations of distinct
knowledge bases and problem solvers. The Algebra of Modular Systems is a
knowledge representation framework that provides a method for formally
specifying such systems in purely semantic terms. Formally, an expression of
the algebra defines a class of structures. Many expressive formalism used in
practice solve the model expansion task, where a structure is given on the
input and an expansion of this structure in the defined class of structures is
searched (this practice overcomes the common undecidability problem for
expressive logics). In this paper, we construct a solver for the model
expansion task for a complex modular systems from an expression in the algebra
and black-box propagators or solvers for the primitive modules. To this end, we
define a general notion of propagators equipped with an explanation mechanism,
an extension of the alge- bra to propagators, and a lazy conflict-driven
learning algorithm. The result is a framework for seamlessly combining solving
technology from different domains to produce a solver for a combined system.Comment: To appear in the proceedings of LPAR 2
High-performance low-loss silicon-on-insulator microring resonators using TM-polarized light
Microring resonators on SOI are investigated for both orthogonal polarizations. By demonstrating low-loss (1.94dB/cm) microring resonators with an intrinsic Q up to 340000 we proof that using TM-polarized light enables high-performance filters
Exploiting Game Theory for Analysing Justifications
Justification theory is a unifying semantic framework. While it has its roots
in non-monotonic logics, it can be applied to various areas in computer
science, especially in explainable reasoning; its most central concept is a
justification: an explanation why a property holds (or does not hold) in a
model. In this paper, we continue the study of justification theory by means of
three major contributions. The first is studying the relation between
justification theory and game theory. We show that justification frameworks can
be seen as a special type of games. The established connection provides the
theoretical foundations for our next two contributions. The second contribution
is studying under which condition two different dialects of justification
theory (graphs as explanations vs trees as explanations) coincide. The third
contribution is establishing a precise criterion of when a semantics induced by
justification theory yields consistent results. In the past proving that such
semantics were consistent took cumbersome and elaborate proofs. We show that
these criteria are indeed satisfied for all common semantics of logic
programming. This paper is under consideration for acceptance in Theory and
Practice of Logic Programming (TPLP).Comment: Paper presented at the 36th International Conference on Logic
Programming (ICLP 2019), University Of Calabria, Rende (CS), Italy, September
2020, 15+8 page
- …