3,596 research outputs found
Bicategories of spans as cartesian bicategories
Bicategories of spans are characterized as cartesian bicategories in which
every comonad has an Eilenberg-Moore ob ject and every left adjoint arrow is
comonadic
Capturing dance: the art of documentation (An exploration of distilling the body in motion)
This research paper is an exploration of documenting and capturing live dance performance in regards to three artistic mediums, Notation, Photography and Film. This piece of writing discusses practitioners who have contributed to the development of these processes such as: Ann Hutchinson Guest, Rudolf von Laban, Eadweard Muybridge, Lois Greenfield, Ted Shawn, Norman McLaren and Sue Healey. In conjunction with historical and current day research the secondary document provided alongside this thesis describes the practical investigation undertaken. The reflections included define first-hand discoveries of how these three mediums of documenting interconnect to describe a contemporary dance solo. Thoughts, findings and results from the studio are provided and discussed to gain further understanding. The aim of this research is to distil and capture the body in motion, to see if it’s possible to produce a document capable of communicating dance when a live body is absent
A colimit decomposition for homotopy algebras in Cat
Badzioch showed that in the category of simplicial sets each homotopy algebra
of a Lawvere theory is weakly equivalent to a strict algebra. In seeking to
extend this result to other contexts Rosicky observed a key point to be that
each homotopy colimit in simplicial sets admits a decomposition into a homotopy
sifted colimit of finite coproducts, and asked the author whether a similar
decomposition holds in the 2-category of categories Cat. Our purpose in the
present paper is to show that this is the case.Comment: Some notation changed; small amount of exposition added in intr
On the 2-categories of weak distributive laws
A weak mixed distributive law (also called weak entwining structure) in a
2-category consists of a monad and a comonad, together with a 2-cell relating
them in a way which generalizes a mixed distributive law due to Beck. We show
that a weak mixed distributive law can be described as a compatible pair of a
monad and a comonad, in 2-categories extending, respectively, the 2-category of
comonads and the 2-category of monads. Based on this observation, we define a
2-category whose 0-cells are weak mixed distributive laws. In a 2-category K
which admits Eilenberg-Moore constructions both for monads and comonads, and in
which idempotent 2-cells split, we construct a fully faithful 2-functor from
this 2-category of weak mixed distributive laws to K^{2 x 2}.Comment: 15 pages LaTeX source, final version to appear in Comm. Algebr
Nomenclatural notes on New South Wales flannel flowers (Actinotus spp., Umbelliferae/Apiaceae) and Leopold Trattinnick’s other Australian plant-names
After a thorough consideration of the history of the European collection and subsequent early cultivation of the commercial flannel flower, a lectotype is designated for Actinotus helianthi Labill. (Umbelliferae/Apiaceae) and the earliest publication (by Trattinnick in 1814) of A. minor (Sm.) Tratt. pinpointed. Other neglected names coined by Trattinnick, including generic ones, applied to Australian and other plants, and published on (generally) plagiarised plates, are discussed and disposed of. One such plate is a copy of the iconotype of Amaryllis × johnsoniana Ker Gawl., an earlier epithet for Hippeastrum × johnsonii (Gowen) Herb. (Amaryllidaceae), a bulbous plant long cultivated in Australia and whose name should be conserved with the later spelling. Attention is drawn to confusions in localities on labels attached to specimens of species (in various families) collected on both D’Entrecasteaux’s and Baudin’s voyages to Australia
Limits of small functors
For a small category K enriched over a suitable monoidal category V, the free
completion of K under colimits is the presheaf category [K*,V]. If K is large,
its free completion under colimits is the V-category PK of small presheaves on
K, where a presheaf is small if it is a left Kan extension of some presheaf
with small domain. We study the existence of limits and of monoidal closed
structures on PK.Comment: 17 page
Thermodynamic graph-rewriting
We develop a new thermodynamic approach to stochastic graph-rewriting. The
ingredients are a finite set of reversible graph-rewriting rules called
generating rules, a finite set of connected graphs P called energy patterns and
an energy cost function. The idea is that the generators define the qualitative
dynamics, by showing which transformations are possible, while the energy
patterns and cost function specify the long-term probability of any
reachable graph. Given the generators and energy patterns, we construct a
finite set of rules which (i) has the same qualitative transition system as the
generators; and (ii) when equipped with suitable rates, defines a
continuous-time Markov chain of which is the unique fixed point. The
construction relies on the use of site graphs and a technique of `growth
policy' for quantitative rule refinement which is of independent interest. This
division of labour between the qualitative and long-term quantitative aspects
of the dynamics leads to intuitive and concise descriptions for realistic
models (see the examples in S4 and S5). It also guarantees thermodynamical
consistency (AKA detailed balance), otherwise known to be undecidable, which is
important for some applications. Finally, it leads to parsimonious
parameterizations of models, again an important point in some applications
Arctic shipping emissions inventories and future scenarios
This paper presents 5 kmĂ—5 km Arctic emissions inventories of important greenhouse gases, black carbon and other pollutants under existing and future (2050) scenarios that account for growth of shipping in the region, potential diversion traffic through emerging routes, and possible emissions control measures. These high-resolution, geospatial emissions inventories for shipping can be used to evaluate Arctic climate sensitivity to black carbon (a short-lived climate forcing pollutant especially effective in accelerating the melting of ice and snow), aerosols, and gaseous emissions including carbon dioxide. We quantify ship emissions scenarios which are expected to increase as declining sea ice coverage due to climate change allows for increased shipping activity in the Arctic. A first-order calculation of global warming potential due to 2030 emissions in the high-growth scenario suggests that short-lived forcing of ~4.5 gigagrams of black carbon from Arctic shipping may increase global warming potential due to Arctic ships' CO<sub>2</sub> emissions (~42 000 gigagrams) by some 17% to 78%. The paper also presents maximum feasible reduction scenarios for black carbon in particular. These emissions reduction scenarios will enable scientists and policymakers to evaluate the efficacy and benefits of technological controls for black carbon, and other pollutants from ships
Nets, relations and linking diagrams
In recent work, the author and others have studied compositional algebras of
Petri nets. Here we consider mathematical aspects of the pure linking algebras
that underly them. We characterise composition of nets without places as the
composition of spans over appropriate categories of relations, and study the
underlying algebraic structures.Comment: 15 pages, Proceedings of 5th Conference on Algebra and Coalgebra in
Computer Science (CALCO), Warsaw, Poland, 3-6 September 201
Simulated ecology-driven sympatric speciation
We introduce a multi-locus genetically acquired phenotype, submitted to
mutations and with selective value, in an age-structured model for biological
aging. This phenotype describes a single-trait effect of the environment on an
individual, and we study the resulting distribution of this trait among the
population. In particular, our simulations show that the appearance of a double
phenotypic attractor in the ecology induces the emergence of a stable
polymorphism, as observed in the Galapagos finches. In the presence of this
polymorphism, the simulations generate short-term speciation, when mating
preferences are also allowed to suffer mutations and acquire selective value.Comment: 11 pages, 5 figures, 1 table, uses package RevTe
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