6,600 research outputs found
Open Petri Nets
The reachability semantics for Petri nets can be studied using open Petri
nets. For us an "open" Petri net is one with certain places designated as
inputs and outputs via a cospan of sets. We can compose open Petri nets by
gluing the outputs of one to the inputs of another. Open Petri nets can be
treated as morphisms of a category , which
becomes symmetric monoidal under disjoint union. However, since the composite
of open Petri nets is defined only up to isomorphism, it is better to treat
them as morphisms of a symmetric monoidal double category
. We describe two forms of semantics
for open Petri nets using symmetric monoidal double functors out of
. The first, an operational semantics,
gives for each open Petri net a category whose morphisms are the processes that
this net can carry out. This is done in a compositional way, so that these
categories can be computed on smaller subnets and then glued together. The
second, a reachability semantics, simply says which markings of the outputs can
be reached from a given marking of the inputs.Comment: 30 pages, TikZ figure
Embroidery and artistic taste
Every aspect of art requires from a person the beauty of the heart, the elegance. One of the most ancient and unique types of applied decorative art is embroider
UCL (University College London) Libraries Masterplan: Masterplanning Report
BDP were appointed to undertake a Masterplan for the UCL Main Library and the
UCL Science Library and to identify how these buildings could be re-ordered to
significantly improve the quality of the library environment and to facilitate the
delivery of library services.
An initial brief was agreed with UCL’s Estates Management Committee and a
Masterplan Steering Group established including academic representatives,
library staff and design consultants. To inform the development of this brief, UCL
Library Services undertook a number of consultation exercises with users of the
Library; students, academic staff and external users, together with Library staff.
A number of visits to exemplar library buildings in the UK and continental Europe
were also undertaken to inform the development of options for the buildings.
Following the development and review of initial options for both the Main Library
and Science Library, it was agreed a further, hypothetical New Build Central
Library Option should be reviewed, to accommodate a relocated and consolidated
library service encompassing 7 of the 16 existing libraries currently distributed
across the UCL Estate
Translating and Evolving: Towards a Model of Language Change in DisCoCat
The categorical compositional distributional (DisCoCat) model of meaning
developed by Coecke et al. (2010) has been successful in modeling various
aspects of meaning. However, it fails to model the fact that language can
change. We give an approach to DisCoCat that allows us to represent language
models and translations between them, enabling us to describe translations from
one language to another, or changes within the same language. We unify the
product space representation given in (Coecke et al., 2010) and the functorial
description in (Kartsaklis et al., 2013), in a way that allows us to view a
language as a catalogue of meanings. We formalize the notion of a lexicon in
DisCoCat, and define a dictionary of meanings between two lexicons. All this is
done within the framework of monoidal categories. We give examples of how to
apply our methods, and give a concrete suggestion for compositional translation
in corpora.Comment: In Proceedings CAPNS 2018, arXiv:1811.0270
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