Search results for " OPTIMA"
showing 10 items of 220 documents
Sustainable Management of Tourist Flow Networks: A Mean Field Model
2023
In this article, we propose a mean field game approach for modeling the flows of excursionists within a network of tourist attractions. We prove the existence of an equilibrium within the network using a balance ordinary differential equation together with optimality conditions in terms of the value function. We also propose a bi-level formulation of the problem where we aim at achieving a sustainable-oriented control strategy in the upper level and at maximizing excursionists’ satisfaction in the lower level. Our proposed model may provide an effective management tool for local authorities who deal with the challenging problem of finding an optimal control policy to the often conflicting o…
Convexities and optimal transport problems on the Wiener space
2013
The aim of this PhD is to study the optimal transportation theory in some abstract Wiener space. You can find the results in four main parts and they are aboutThe convexity of the relative entropy. We will extend the well known results in finite dimension to the Wiener space, endowed with the uniform norm. To be precise the relative entropy is (at least weakly) geodesically 1-convex in the sense of the optimal transportation in the Wiener space.The measures with logarithmic concave density. The first important result consists in showing that the Harnack inequality holds for the semi-group induced by such a measure in the Wiener space. The second one provides us a finite dimensional and dime…
Survey of methods to visualize alternatives in multiple criteria decision making problems
2012
When solving decision problems where multiple conflicting criteria are to be considered simultaneously, decision makers must compare several different alternatives and select the most preferred one. The task of comparing multidimensional vectors is very demanding for the decision maker without any support. Different graphical visualization tools can be used to support and help the decision maker in understanding similarities and differences between the alternatives and graphical illustration is a very important part of decision support systems that are used in solving multiple criteria decision making problems. The visualization task is by no means trivial because, on the one hand, the grap…
Analysis of Optimal High Resolution and Fixed Rate Scalar Quantization
2009
In 2001, Hui and Neuhoff proposed a uniform quantizer with overload for the quantization of scalar signals and derived the asymptotically optimal size of the quantization bins in the high-bitrate limit. The purpose of the present paper is to prove a quantitatively more precise version of this result which, at the same time, is valid for a more general, quite natural class of probability distributions that requires only little regularity and includes, for instance, positive Lipschitz-continuous functions of unit integral.
Best proximity point theorems for rational proximal contractions
2013
Abstract We provide sufficient conditions which warrant the existence and uniqueness of the best proximity point for two new types of contractions in the setting of metric spaces. The presented results extend, generalize and improve some known results from best proximity point theory and fixed-point theory. We also give some examples to illustrate and validate our definitions and results. MSC:41A65, 46B20, 47H10.
Motor decision and modular control of an hyper-redundant system
2015
This thesis is aimed at better understanding how the Central Nervous System (CNS) plans and controls voluntary movements. When moving, humans must overcome intrinsic (e.g. choosing which muscles to activate) and extrinsic (e.g. choosing where to reach an object) redundancy, requiring selecting one motor solution among several potential ones. To better understand this process, we studied in parallel two important motor control theories: muscular synergies and motor decision. In a first part, we focused on intrinsic redundancy by testing the muscular synergies hypothesis. According to it, the CNS simplifies the control of muscles, in using a limited set of building blocks whose linear combina…
Vegetation Types Mapping Using Multi-Temporal Landsat Images in the Google Earth Engine Platform
2021
Vegetation Types (VTs) are important managerial units, and their identification serves as essential tools for the conservation of land covers. Despite a long history of Earth observation applications to assess and monitor land covers, the quantitative detection of sparse VTs remains problematic, especially in arid and semiarid areas. This research aimed to identify appropriate multi-temporal datasets to improve the accuracy of VTs classification in a heterogeneous landscape in Central Zagros, Iran. To do so, first the Normalized Difference Vegetation Index (NDVI) temporal profile of each VT was identified in the study area for the period of 2018, 2019, and 2020. This data revealed strong se…
Composition des dépenses publiques et impacts sur la croissance économique : analyses théoriques et empiriques sur des panels de pays développés, éme…
2016
The economic role of the State has been the subject of much debate both from theoretical and the practical perspectives. The actors of these controversies include the objectors of the efficiency of the public intervention since Smith to the present days, Keynesians and economists of the synthesis. Topics ranging from principle of the invisible hand, tax, expectations, burden of the debt, crowding out effect, public sector production are treated through of such debates. The work explains the breakdown of public spending components and implications for countries at levels development (OECD, BRICS, and WAEMU). The study also indicated that the effects of the public spending and its components …
Optimal Sustainable Policies Under Pollution Ceiling: the Demographic Side
2014
AD; International audience; We study optimal sustainable policies in a benchmark logistic world (where both population and technological progress follow logistic laws of motion) subject to a pollution ceiling. The main policy in the hands of the benevolent planner is pollution abatement, ultimately leading to the control of a dirtiness index as in the early literature of the limits to growth literature. Besides inclusion of demographic dynamics, we also hypothesize that population size affects negatively the natural regeneration or assimilation rate, as a side product of human activities (like increasing pollution, deforestation, ...). We first characterize optimal sustainable policies. Und…
Bryophytes collected during the 12th “Iter Mediterraneum” (Tunisia, 24 March – 4 April, 2014). First contribution
2015
Part of the bryophytes collected during Iter Mediterraneum XII is listed. Some noteworthy species were found: Dicranella howei, had so far been recorded only doubtfully from Tunisia; Funaria hygrometrica, Grimmia laevigata, Grimmia trichophylla, Imbribryum alpinum, Pogonatum nanum, Rhynchostegium riparioides, Scleropodium touretii, Scorpiurium circinatum, Thamnobryum alopecurum, Timmiella barbuloides, Tortella squarrosa, Tortula muralis and Tortula vahliana, had not been reported from that country for more than half a century.