FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2788406930> ?p ?o ?g. }

• W2788406930 abstract "In this thesis, we analyze the dynamics of discrete event systems with synchronization and priorities, by the means of Petri nets and queueing networks.We apply this to the performance evaluation of an emergency call center.Our original motivation is practical. During the period of this work, a new emergency call center became operative in Paris area, handling emergency calls to police and firemen.The new organization includes a two-level call treatment. A first level of operators answers calls, identifies urgent calls and handles (numerous) non-urgent calls.Second level operators are specialists (policemen or firemen) and handle emergency demands.When a call is identified at level 1 as extremely urgent, the operator stays in line with the call until a level 2 operator answers. The call has priority for level 2 operators.A consequence of this procedure is that, when level 2 operators are busy, level 1 operators wait with extremely urgent calls, and the capacity of level 1 diminishes.We are interested in the performance evaluation of various systems corresponding to this general description, in stressed situations.We propose three different models addressing this kind of systems.The first two are timed Petri net models.We enrich the classical free choice Petri nets by allowing conflict situations in which the routing is solved by priorities.The main difficulty in this situation is that the operator of the dynamics becomes non monotone.In a first model, we consider discrete dynamics for this class of Petri nets, with constant holding times on places.We prove that the counter variables of an execution of the Petri net are solutions of a piecewise linear system with delays.As far as we know, this proof is new, even for the class of free choice nets, which is a subclass of ours.We investigate the stationary regimes of the dynamics, and characterize the affine ones as solutions of a piecewise linear system, which can be seen as a system over a tropical (min-plus) semifield of germs.Numerical experiments show that, however, convergence does not always holds towards these affine stationary regimes.The second model is a ``continuization'' of the previous one. For the same class of Petri nets, we propose dynamics expressed by differential equations, so that the tokens and time events become continue.For this differential system with discontinuous righthandside, we establish the existence and uniqueness of the solution.By using differential equations, we aim at obtaining a simpler model in which discrete time pathologies disappear. We show that the stationary regimes are the same as the stationary regimes of the discrete time dynamics.Numerical experiments tend to show that, in this setting, convergence effectively holds.We also model the emergency call center described above as a queueing system, taking into account the randomness of the different call center variables.For this system, we prove that, under an appropriate scaling, the dynamics converges to a fluid limit which corresponds to the differential equations of our Petri net model.This provides support for the second model.Stochastic calculus for Poisson processes, generalized Skorokhod formulations and coupling arguments are the main tools used to establish this convergence.Hence, our three models of an identical emergency call center yield the same schematic asymptotic behavior, expressed as a piecewise linear system of the parameters, and describing the different congestion phases of the system.In a second part of this thesis, simulations are carried out and analyzed, taking into account the many subtleties of our case study (for example, we construct probability distributions based on real data analysis).The simulations confirm the schematic behavior described by our mathematical models.We also address the complex interactions coming from the heterogeneous nature of level 2." @default.
• W2788406930 created "2018-03-06" @default.
• W2788406930 creator A5023458282 @default.
• W2788406930 date "2017-12-18" @default.
• W2788406930 modified "2023-09-25" @default.
• W2788406930 title "Dynamics of a two-level system with priorities and application to an emergency call center" @default.
• W2788406930 hasPublicationYear "2017" @default.
• W2788406930 type Work @default.
• W2788406930 sameAs 2788406930 @default.
• W2788406930 citedByCount "0" @default.
• W2788406930 crossrefType "dissertation" @default.
• W2788406930 hasAuthorship W2788406930A5023458282 @default.
• W2788406930 hasConcept C104317684 @default.
• W2788406930 hasConcept C120314980 @default.
• W2788406930 hasConcept C121332964 @default.
• W2788406930 hasConcept C127162648 @default.
• W2788406930 hasConcept C158448853 @default.
• W2788406930 hasConcept C17020691 @default.
• W2788406930 hasConcept C185592680 @default.
• W2788406930 hasConcept C197551870 @default.
• W2788406930 hasConcept C22684755 @default.
• W2788406930 hasConcept C2778562939 @default.
• W2788406930 hasConcept C2779662365 @default.
• W2788406930 hasConcept C31258907 @default.
• W2788406930 hasConcept C33923547 @default.
• W2788406930 hasConcept C38677869 @default.
• W2788406930 hasConcept C41008148 @default.
• W2788406930 hasConcept C42475967 @default.
• W2788406930 hasConcept C55493867 @default.
• W2788406930 hasConcept C62520636 @default.
• W2788406930 hasConcept C76155785 @default.
• W2788406930 hasConcept C86339819 @default.
• W2788406930 hasConceptScore W2788406930C104317684 @default.
• W2788406930 hasConceptScore W2788406930C120314980 @default.
• W2788406930 hasConceptScore W2788406930C121332964 @default.
• W2788406930 hasConceptScore W2788406930C127162648 @default.
• W2788406930 hasConceptScore W2788406930C158448853 @default.
• W2788406930 hasConceptScore W2788406930C17020691 @default.
• W2788406930 hasConceptScore W2788406930C185592680 @default.
• W2788406930 hasConceptScore W2788406930C197551870 @default.
• W2788406930 hasConceptScore W2788406930C22684755 @default.
• W2788406930 hasConceptScore W2788406930C2778562939 @default.
• W2788406930 hasConceptScore W2788406930C2779662365 @default.
• W2788406930 hasConceptScore W2788406930C31258907 @default.
• W2788406930 hasConceptScore W2788406930C33923547 @default.
• W2788406930 hasConceptScore W2788406930C38677869 @default.
• W2788406930 hasConceptScore W2788406930C41008148 @default.
• W2788406930 hasConceptScore W2788406930C42475967 @default.
• W2788406930 hasConceptScore W2788406930C55493867 @default.
• W2788406930 hasConceptScore W2788406930C62520636 @default.
• W2788406930 hasConceptScore W2788406930C76155785 @default.
• W2788406930 hasConceptScore W2788406930C86339819 @default.
• W2788406930 hasLocation W27884069301 @default.
• W2788406930 hasOpenAccess W2788406930 @default.
• W2788406930 hasPrimaryLocation W27884069301 @default.
• W2788406930 hasRelatedWork W1532042485 @default.
• W2788406930 hasRelatedWork W1545632625 @default.
• W2788406930 hasRelatedWork W160316085 @default.
• W2788406930 hasRelatedWork W1603479876 @default.
• W2788406930 hasRelatedWork W1750781857 @default.
• W2788406930 hasRelatedWork W1994008028 @default.
• W2788406930 hasRelatedWork W2037726428 @default.
• W2788406930 hasRelatedWork W2161617103 @default.
• W2788406930 hasRelatedWork W2172102371 @default.
• W2788406930 hasRelatedWork W2262413573 @default.
• W2788406930 hasRelatedWork W2346489414 @default.
• W2788406930 hasRelatedWork W2765764116 @default.
• W2788406930 hasRelatedWork W2890549119 @default.
• W2788406930 hasRelatedWork W2911498600 @default.
• W2788406930 hasRelatedWork W3017008472 @default.
• W2788406930 hasRelatedWork W3111874402 @default.
• W2788406930 hasRelatedWork W3163787131 @default.
• W2788406930 hasRelatedWork W610169158 @default.
• W2788406930 hasRelatedWork W618873733 @default.
• W2788406930 hasRelatedWork W64054199 @default.
• W2788406930 isParatext "false" @default.
• W2788406930 isRetracted "false" @default.
• W2788406930 magId "2788406930" @default.
• W2788406930 workType "dissertation" @default.