869 research outputs found
Distilling Abstract Machines (Long Version)
It is well-known that many environment-based abstract machines can be seen as
strategies in lambda calculi with explicit substitutions (ES). Recently,
graphical syntaxes and linear logic led to the linear substitution calculus
(LSC), a new approach to ES that is halfway between big-step calculi and
traditional calculi with ES. This paper studies the relationship between the
LSC and environment-based abstract machines. While traditional calculi with ES
simulate abstract machines, the LSC rather distills them: some transitions are
simulated while others vanish, as they map to a notion of structural
congruence. The distillation process unveils that abstract machines in fact
implement weak linear head reduction, a notion of evaluation having a central
role in the theory of linear logic. We show that such a pattern applies
uniformly in call-by-name, call-by-value, and call-by-need, catching many
machines in the literature. We start by distilling the KAM, the CEK, and the
ZINC, and then provide simplified versions of the SECD, the lazy KAM, and
Sestoft's machine. Along the way we also introduce some new machines with
global environments. Moreover, we show that distillation preserves the time
complexity of the executions, i.e. the LSC is a complexity-preserving
abstraction of abstract machines.Comment: 63 page
From Operator Algebras to Superconformal Field Theory
We make a review on the recent progress in the operator algebraic approach to
(super)conformal field theory. We discuss representation theory, classification
results, full and boundary conformal field theories, relations to supervertex
operator algebras and Moonshine, connections to subfactor theory and
noncommutative geometry
Subfactors and coset models
Some facts about von Neumann algebras and finite index inclusions of factors
are viewed in the context of local quantum field theory. The possibility of
local fields intertwining superselection sectors with braid group statistics is
explored. Conformal embeddings and coset models serve as examples. The
associated symmetry concept is pointed out.Comment: Latex, 18 pages, DESY 93-11
Energy aware knowledge extraction from Petri nets supporting decision-making in service-oriented automation
This paper introduces an approach to decision support systems in service-oriented automation control systems, which considers the knowledge extracted from the Petri nets models used to describe and execute the process behavior. Such solution optimizes the decision-making taking into account multi-criteria, namely productive parameters and also energy parameters. In fact, being manufacturing processes typically energy-intensive, this allows contributing for a clean and saving environment (i.e. a better and efficient use of energy). The preliminary experimental results, using a real laboratorial case study, demonstrate the applicability of the knowledge extracted from the Petri nets models to support real-time decision-making systems in service-oriented automation systems, considering some energy efficiency criteria
Subfactors and Conformal Field Theory
Connections between subfactor theory and conformal field theory have been expected since the early days of the former in 1980’s, and recently we see more and more evidence for deeper relations. It was our aim to attract experts from a wide range of topics related to subfactors and CFT. Many of the participants met for the first time at Oberwolfach, and there were numerous very fruitful interactions
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