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Mardi 4 Février
Heure: |
12:00 - 13:30 |
Lieu: |
Salle B107, bâtiment B, Université de Villetaneuse |
Résumé: |
Capacity Planning for Natural Gas Transmission Networks |
Description: |
Jesco Humpola We present a procedure for capacity planning of large-scale real-world natural gas distribution networks. It decides which combination of network extensions such as additional pipelines, compressors or valves should be added to increase the network's capacity or enhance its operational flexibility. We formulate this as a mixed-integer nonlinear problem. A sub-problem has different convex reformulations. Hence we use a combination of linear outer approximation and NLP solution techniques to solve the MINLP. We show that every dual solution of the convex reformulations allows to generate capacity inequalities (or cutting planes) which reduce the overall solution time when added to the formulation. The dual solution also enables the measurement of infeasibility level of the scenario. Furthermore we give a primal heuristic for our model. We present computational results that are obtained by a special tailored version of the solvers SCIP and IPOPT. |
Vendredi 7 Février
Heure: |
00:59 - 12:00 |
Lieu: |
Salle B107, bâtiment B, Université de Villetaneuse |
Résumé: |
Models of a Non-Associative Composition |
Description: |
Guillaume Munch-Maccagnoni We characterise the polarised evaluation order through a categorical structure where the hypothesis that composition is associative is relaxed. Duploid is the name of the structure, as a reference to Jean-Louis Loday's duplicial algebras. The main result is a reflection AdjâDupl where Dupl is a category of duploids and duploid functors, and Adj is the category of adjunctions and pseudo maps of adjunctions. The result suggests that the various biases in denotational semantics: indirect, call-by-value, call-by-name... are a way of hiding the fact that composition is not always associative. |
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