Fiche du "kit de survie de l'helléniste": syntaxe de "an".

Cette anthologie propose une vue en coupe de mille ans d’'écriture occitane : une géologie de notre mémoire et un panorama du présent. L’'occitan n’'a cessé de s'’écrire pendant tout le second millénaire de notre ère et il conserve cette bonne habitude depuis l’'avènement du troisième.

Cette longue durée d'écriture repose sur un paradoxe : l’'une des plus anciennes langues de culture d’'Europe, sinon la plus ancienne depuis le Haut Moyen-Âge, s’'écrit en marge de toute institution littéraire nationale, de façon quasi clandestine, en tout cas marginale, se voyant refuser toute reconnaissance, tout prestige, voire tout droit à produire une grande, une haute littérature.

Nous traitions déjà de cette question dans un précédent projet UOH : L’'occitan, une langue, une littérature, une histoire, qui visait à donner un aperçu rapide d’un millénaire d’'écrit occitan mis en perspective historique. Nous avons choisi cette fois de mettre l’'accent sur des textes et les auteurs.

 

The environment is a social issue that continues to grow in importance. Its complexity, both cross-disciplinary and multi-scale, has given rise to a large number of scientific and technological locks, that can be solved using a complex systems approaches. Through this courses we will give some examples of complex systems that can be found in environment and their observable, we will highlight the variability of these fields over a wide range of scales. We will focus on the fractal/multifractal behaviour of the environnemental fields and introduce some tools that allow us to charchterize their spatial/temporal variability. The courses is devided in 11 modules as follows: -Introduction -Source of Complexity -Dynamical Systems -Cascade Phenomenology -Spectral Analysis -MultiScale Analysis: Fractal -MultiScale Analysis :Multifractal -Multiscale Analysis: Methods of Analysis -MultiScale Simulations -Extremes -Resilience

We introduce in this lecture the spectral analysis which is based on the Fourier transform. The main objective of using this can of analysis in our studies is to check the scale invariance propriety of the studied field and also to identify the involved processes. The spectral analysis is widely used in fluid dynamics especially in turbulence field. We will show in this lesson that the spectrum of the studied field in log-log plot is characterized by a given slope which allows us to identify the involved process. We will start this lesson by an introduction to the Fourier transform and the discrete Fourier transform, after that we will mention some domain of application of the spectral analysis and we will finish by the identification of some process in geophysics. Module 5 of the course set "An Introduction to Complex Systems in Environment"

Urban flooding is due to a lack of drainage in an urban area. Because of the impervious area, there is little open soil that can be used for infiltration and water storage. Nearly all the precipitation needs to be transfer to surface water or the sewage system. High intensity rainfall can cause flooding when the city sewage system and draining canals do not have the necessary capacity to drain away the amounts of rain... Module 11 of the course set "An Introduction to Complex Systems in Environment"

We saw in the previous lesson some complex systems that can be found in environment. We also highlighted that there is non single definition of complexity. Through this lesson we will focus on the sources of complexity in a given system, what are the issues that can arise for the best model a complex system such as: at what scale should we describe the behaviors of the system's components?. What are the scales involved in the evolution of the system?. We can list some characteristics of complex systems: Too many components, too many constraints, too many parameters for consideration to accomplish a particular task. Not enough information about essential elements or components of a system or about their interfaces. Not enough information about how elements or components will behave under known or unknown conditions that may lead to unintended consequences Among the sources of complexity we will focus on the non-linearity of complex systems and differential equations which describe them. We will show that some methods of analysis based on scale invariance can be considered as good candidates for the characterization of complex systems. Second module of the course set "An Introduction to Complex Systems in Environment"

When we describe the evolution of a system we use several variables, i.e. a set of magnitudes, functions of space and time, the values of which define everything we know about the system completely and unambiguously. Then, the evolution of the systems is given by the evolution of the set of variables, according to some specific laws. A dynamic system is defined by a set of variables and a set of differential equations. During this lesson, we will focus on a mathematical description of dynamical systems using ODEs, we will discuss the stability in time of such systems and their evolution to the chaos. Third module of the course set "An Introduction to Complex Systems in Environment"

The extreme value theory deals with the stochastic behavior of the minimum and the maximum of random variable. It involves a large variety of applications such as natural phenomena: rainfall, floods, atmospheric turbulence, corrosion...etc. The distribution proprieties of extremes and intermediate order statistics are determined by the upper and lower tails of the probability distribution. Module 10 of the course set "An Introduction to Complex Systems in Environment"

Multiplicative cascade processes are frequently used as phenomenological models for the study of a variety of complex systems exhibiting fractal/multifractal behavior. In particular the energy dissipation field of fully developed turbulent flows has been most successfully modeled in such terms, physically motivated by Richardson's poem of energy transfer from large to small scales by random breakups of eddies. Multiplicative cascade models are based on two assumptions: the existence of a scale-independent and statistical independence of the random weights at one breakup from those of any other breakup. During this lesson, we will give the principle of cascade and in which context were developed. We introduce three types of models that describe the cascade phenomenology. We finished with two exercises which allows us to play with -model and the -model. Module 4 of the course set "An Introduction to Complex Systems in Environment"