24,208 research outputs found
On the p-media polytope of special class of graphs
Dans cet article nous étudions les inégalités de cycles impairs. Nous donnons un nouvel algorithme de séparation de ces inégalités, et nous montrons que lorsque nous ajoutons ces inégalités aux inégalités de la relaxation linéaire nous obtenons le polytope du p-médian dans la classe des graphes sans Y. Pour cela nous caractérisons d'abord les points extrêmesfractionnaires du système défini par la relaxation linéaire dans les graphes sans Y.
Gradient-prolongation commutativity and graph theory
This Note gives conditions that must be imposed to algebraic multilevel
discretizations involving at the same time nodal and edge elements so that a
gradient-prolongation commutativity condition will be satisfied; this condition
is very important, since it characterizes the gradients of coarse nodal
functions in the coarse edge function space. They will be expressed using graph
theory and they provide techniques to compute approximation bases at each
level.Comment: 6 page
Cyclic Foam Topological Field Theories
This paper proposes an axiomatic for Cyclic Foam Topological Field theories.
That is Topological Field theories, corresponding to String theories, where
particles are arbitrary graphs. World surfaces in this case are two-manifolds
with one-dimensional singularities. We proved that Cyclic Foam Topological
Field theories one-to-one correspond to graph-Cardy-Frobenius algebras, that
are families , where are families of
commutative associative Frobenius algebras, is an graduated by graphes, associative
algebras of Frobenius type and is a family of special representations. There are
constructed examples of Cyclic Foam Topological Field theories and its
graph-Cardy-Frobenius algebrasComment: 14 page
A review of information flow diagrammatic models for product-service systems
A product-service system (PSS) is a combination of products and services to
create value for both customers and manufacturers. Modelling a PSS based on
function orientation offers a useful way to distinguish system inputs and
outputs with regards to how data are consumed and information is used, i.e.
information flow. This article presents a review of diagrammatic information
flow tools, which are designed to describe a system through its functions. The
origin, concept and applications of these tools are investigated, followed by an
analysis of information flow modelling with regards to key PSS properties. A
case study of selection laser melting technology implemented as PSS will then be
used to show the application of information flow modelling for PSS design. A
discussion based on the usefulness of the tools in modelling the key elements of
PSS and possible future research directions are also presented
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