Search results for "102"
showing 10 items of 2892 documents
Robust Mean Field Games with Application to Production of an Exhaustible Resource
2012
International audience; In this paper, we study mean field games under uncertainty. We consider a population of players with individual states driven by a standard Brownian motion and a disturbance term. The contribution is three-fold: First, we establish a mean field system for such robust games. Second, we apply the methodology to an exhaustible resource production. Third, we show that the dimension of the mean field system can be significantly reduced by considering a functional of the first moment of the mean field process.
The minimum mean cycle-canceling algorithm for linear programs
2022
Abstract This paper presents the properties of the minimum mean cycle-canceling algorithm for solving linear programming models. Originally designed for solving network flow problems for which it runs in strongly polynomial time, most of its properties are preserved. This is at the price of adapting the fundamental decomposition theorem of a network flow solution together with various definitions: that of a cycle and the way to calculate its cost, the residual problem, and the improvement factor at the end of a phase. We also use the primal and dual necessary and sufficient optimality conditions stated on the residual problem for establishing the pricing step giving its name to the algorith…
Gray code for derangements
2004
AbstractWe give a Gray code and constant average time generating algorithm for derangements, i.e., permutations with no fixed points. In our Gray code, each derangement is transformed into its successor either via one or two transpositions or a rotation of three elements. We generalize these results to permutations with number of fixed points bounded between two constants.
Best proximity point theorems for proximal cyclic contractions
2017
The purpose of this article is to compute a global minimizer of the function $$x\longrightarrow d(x, Tx)$$ , where T is a proximal cyclic contraction in the framework of a best proximally complete space, thereby ensuring the existence of an optimal approximate solution, called a best proximity point, to the equation $$Tx=x$$ when T is not necessarily a self-mapping.
Combined column-and-row-generation for the optimal communication spanning tree problem
2018
Abstract This paper considers the exact solution of the optimal communication spanning tree problem (OCSTP), which can be described as follows: Given an undirected graph with transportation costs on every edge and communication requirements for all pairs of vertices, the OCSTP seeks for a spanning tree that minimizes the sum of the communication costs between all pairs of vertices, where the communication cost of a pair of vertices is defined as their communication requirement multiplied by the transportation cost of the unique tree path that connects the two vertices. Two types of compact formulations for OCSTP were presented in the literature. The first one is a four-index model based on …
Heuristics for the min–max arc crossing problem in graphs
2018
Abstract In this paper, we study the visualization of complex structures in the context of automatic graph drawing. Constructing geometric representations of combinatorial structures, such as networks or graphs, is a difficult task that requires an expert system. The automatic generation of drawings of graphs finds many applications from software engineering to social media. The objective of graph drawing expert systems is to generate layouts that are easy to read and understand. This main objective is achieved by solving several optimization problems. In this paper we focus on the most important one: reducing the number of arc crossings in the graph. This hard optimization problem has been…
Kick Detection and Influx Size Estimation during Offshore Drilling Operations using Deep Learning
2019
An uncontrolled or unobserved influx or kick during drilling has the potential to induce a well blowout, one of the most harmful incidences during drilling both in regards to economic and environmental cost. Since kicks during drilling are serious risks, it is important to improve kick and loss detection performance and capabilities and to develop automatic flux detection methodology. There are clear patterns during a influx incident. However, due to complex processes and sparse instrumentation it is difficult to predict the behaviour of kicks or losses based on sensor data combined with physical models alone. Emerging technologies within Deep Learning are however quite adapt at picking up …
Infarctus du myocarde au cours de l’artérite à cellules géantes : étude de cohorte
2020
Introduction Le risque d’evenement cardiovasculaire est accru au cours de l’arterite a cellules geantes (ACG), en particulier dans les premiers mois suivant le diagnostic de la vascularite [1] . L’objectif de ce travail etait de decrire les caracteristiques des infarctus du myocarde (IDM) survenant chez des patients atteints d’ACG et de les comparer avec des IDM survenant chez des patients ne presentant pas d’ACG au moment de leur IDM. Patients et methodes Les patients atteints d’ACG ont ete identifies parmi la liste des biopsies d’artere temporale (BAT) qui montraient des lesions d’ACG et qui avaient ete analysees entre le 1er janvier 2001 et le 31 decembre 2016 dans les deux laboratoires …
Der Zellkern - eine Stadt in der Zelle
2016
Gespeicherte genetische Information allein nutzt nichts, wenn sie nicht zur richtigen Zeit und am richtigen Ort abgerufen werden kann. Die Verpackung der DNA im Chromatin des Zellkerns und dessen dynamische, raum-zeitliche Anordnung haben einen entscheidenden Einfluss auf die Genexpression und weitere Funktionen des Zellkerns. In dieser Ubersichtsarbeit beschreiben die Verfasser die Entwicklung der experimentellen Zellkernarchitektur-Forschung und die damit einhergehenden Veranderungen der Vorstellungen zur funktionellen Organisation des Zellkerns.
Zilienabhängige RPE-Zellentwicklung und der WNT-Signalweg
2020
ZusammenfassungDas retinale Pigmentepithel (RPE) ist eine hochpolarisierte Einzelschicht quaderförmiger Epithelzellen, die dicht mit Melanin gepackt sind. Sie liegt zwischen den lichtempfindlichen Außensegmenten der Photorezeptoren und der Aderhaut (Choroidea), spielt eine essenzielle Rolle bei der Entwicklung der Photorezeptoren und übernimmt wichtige Funktionen in Bezug auf Nährstoffversorgung und Erhaltung, im Retinalstoffwechsel und bei der Abschirmung von der Blutversorgung der Aderhaut. Die Photorezeptoren durchlaufen täglich einen Erneuerungsprozess, bei dem 10% der äußeren Segmente durch das retinale Pigmentepithel phagozytiert werden. Dies erfordert eine enge Wechselwirkung zwische…