CONSTITUTIVE MODELLING FOR ANISOTROPIC HARDENING BEHAVIOR WITH APPLICATIONS TO COHESIONLESS SOILS (INDUCED, KINEMATIC, NON-ASSOCIATIVENESS).

A constitutive model based on rate-independent elastoplasticity concepts is developed to simulate the behavior of geologic materials under arbitrary three-dimensional stress paths, stress reversals and cyclic loading. The model accounts for the various factors such as friction, stress path, stress history, induced anisotropy and initial anisotropy that influence the behavior of geologic materials. A hierarchical approach is adapted whereby models of progressively increasing sophistication are developed from a basic isotropic-hardening associative model. The influence of the above factors is captured by modifying the basic model for anisotropic (kinematic) hardening and deviation from normality (nonassociativeness). Both anisotropic hardening and deviation from normality are incorporated by introducing into the formulation a second order tensor whose evolution is governed by the level of induced anisotropy in the material. In the stress-space this formulation may be interpreted as a translating potential surface Q that moves in a fixed field of isotropic yield surfaces. The location of the translating surface in the stress-space, at any stage of the deformation, is given by the 'induced anisotropy' tensor. A measure to represent the level of induced anisotropy in the material is defined. The validity of this representation is investigated based on a series of special stress path tests in the cubical triaxial device on samples of Leighton Buzzard sand. The significant parameters of the models are defined and determined for three sands based on results of conventional laboratory test results. The model is verified with respect to laboratory multiaxial test data under various paths of loading, unloading, reloading and cyclic loading

Indian financial structure : resilient to the global crisis?

Cette thèse présente dans un premier temps l’histoire récente et les enjeux de l’économie et du système financier indien. Puis, en se concentrant la période récente, elle étudie la question de l’intégration financière sur différents marchés : les marchés actions sont traités dans le 1er chapitre, les spreads des CDS indiens sont abordés dans 2nd chapitre et la relation entre les prix des matières premières et la politique monétaire est analysée dans le 3e chapitre. Enfin, le dernier chapitre pose la question de savoir si un secteur bancaire plus efficient peut aider l’économie indienne à sortir de la crise. Globalement, les résultats indiquent que les marchés étudiés sont plus intégrés depuis la crise, ce qui suggère une fragilité du secteur financier indien aux chocs extérieurs. Néanmoins, les résultats du chapitre 4 montrent, dans le cadre d’un modèle simple, que le système financier peut aussi permettre à l’économie indienne de surmonter ses déboires actuels, s’il l’on y implémente les réformes adéquates et que la productivité des banques est améliorée.This thesis first presents India’s economy and financial system’s recent history and current issues. Then, with an emphasis on the recent turmoil period, it studies the question of financial integration in various markets: equity markets are dealt with in the 1st chapter, CDS spreads are analyzed in the 2nd chapter while the 3rd chapter focuses on the monetary policy-commodity prices nexus. Finally, the last chapter reflects on the ability of the banking system to help the country out of the current crisis. Overall, our results indicate that markets are more integrated since the crisis, which suggest a frailty of the Indian financial structure to exterior shocks. Nevertheless, results for chapter 4 show that the financial system could also allow the economy to recover if the proper reforms are implemented and that banking efficiency is improved

Le système financier indien à l'épreuve de la crise

This thesis first presents India’s economy and financial system’s recent history and current issues. Then, with an emphasis on the recent turmoil period, it studies the question of financial integration in various markets: equity markets are dealt with in the 1st chapter, CDS spreads are analyzed in the 2nd chapter while the 3rd chapter focuses on the monetary policy-commodity prices nexus. Finally, the last chapter reflects on the ability of the banking system to help the country out of the current crisis. Overall, our results indicate that markets are more integrated since the crisis, which suggest a frailty of the Indian financial structure to exterior shocks. Nevertheless, results for chapter 4 show that the financial system could also allow the economy to recover if the proper reforms are implemented and that banking efficiency is improved.Cette thèse présente dans un premier temps l’histoire récente et les enjeux de l’économie et du système financier indien. Puis, en se concentrant la période récente, elle étudie la question de l’intégration financière sur différents marchés : les marchés actions sont traités dans le 1er chapitre, les spreads des CDS indiens sont abordés dans 2nd chapitre et la relation entre les prix des matières premières et la politique monétaire est analysée dans le 3e chapitre. Enfin, le dernier chapitre pose la question de savoir si un secteur bancaire plus efficient peut aider l’économie indienne à sortir de la crise. Globalement, les résultats indiquent que les marchés étudiés sont plus intégrés depuis la crise, ce qui suggère une fragilité du secteur financier indien aux chocs extérieurs. Néanmoins, les résultats du chapitre 4 montrent, dans le cadre d’un modèle simple, que le système financier peut aussi permettre à l’économie indienne de surmonter ses déboires actuels, s’il l’on y implémente les réformes adéquates et que la productivité des banques est améliorée

Towards a Scalable Parallel Object Database - The Bulk Synchronous Parallel Approach

Parallel computers have been successfully deployed in many scientific and numerical application areas, although their use in non-numerical and database applications has been scarce. In this report, we first survey the architectural advancements beginning to make general-purpose parallel computing cost-effective, the requirements for non-numerical (or symbolic) applications, and the previous attempts to develop parallel databases. The central theme of the Bulk Synchronous Parallel model is to provide a high level abstraction of parallel computing hardware whilst providing a realisation of a parallel programming model that enables architecture independent programs to deliver scalable performance on diverse hardware platforms. Therefore, the primary objective of this report is to investigate the feasibility of developing a portable, scalable, parallel object database, based on the Bulk Synchronous Parallel model of computation. In particular, we devise a way of providing high-level abstra..

The links between some European financial factors and the BRICS credit default swap spreads

International audienceEmerging economies and especially the BRICS countries have strong economic ties with the euro area. In addition, the financial crisis in the euro area may have effects on other markets or areas, especially those of the main emerging markets. Credit default swap (CDS) spreads are relevant indicators of credit risks. After identifying a set of fundamental determinants for sovereign CDS spreads, including euro area financial factors and computing Markov switching unit root test, we estimate Markov switching models over the period from January 2002 to August 2012, in order to examine the behaviour of sovereign CDS spreads in the BRICS countries. , i) We detect two different regimes for the BRICS, that finding is backed by conventional robustness checks and economic events; ii) most of the explanatory variables are involved in the determining theses regimes. Thus both financial and real factors have an impact on the relations defining each regime, except for Russia which is only impacted by financial ones. Especially, euro area financial indicators are largely involved in the BRICS sovereign CDS spreads’ dynamics. Besides, the robustness check supports the use of euro area variables as determinants of BRICS sovereign CDS spreads

Transgressing The Boundaries: Unified Scalable Parallel Programming

The diverse architectural features of parallel computers, and the lack of commonly accepted parallel-programming environments, meant that software development for these systems has been significantly more difficult than the sequential case. Until better approaches are developed, the programming environment will remain a serious obstacle to mainstream scalable parallel computing. The work reported in this paper attempts to integrate architectureindependent scalable parallel programming in the Bulk Synchronous Parallel (BSP) model with the shared-memory parallel programming using the theoretical PRAM model. We start with a discussion of problem parallelism, that is, the parallelism inherent to a problem instead of a specific algorithm, and the parallel-programming techniques that allow the capture of this notion. We then review the ubiquitous PRAM model in terms of the model's pragmatic limitations, where particular attention is paid to simulations on practical machines. The BSP model i..

On the determinants of food price volatility

International audienceIn this paper, we investigate the determinants of price volatility for six major food commodities fromJanuary 2001 to March 2013. In the recent literature, real economic activity, biofuel production, oilprices and financial markets indicators are commonly considered to be the main drivers of pricevolatility. We identify and analyse the relationships between these macroeconomic and financialfactors and our commodities within a Bayesian multivariate framework. Then we assess the effect ofeach factor on food volatility in the recent period. We show that, although results depend on foodcommodities, they are consistent with those available in the latest studies. In other words, the twomost recent surges in food prices do not significantly change the dynamics of these prices. We havealso performed an analysis of the effects of certain shocks on food commodity markets. Theseexercises do not reveal the existence of coherent groups of food commodities

Does Monetary Policy Respond to Commodity Price Shocks?

International audienceCommodity prices, especially oil prices, peaked in the aftermath of the financial crisis of 2007 and they have remained highly volatile. All things being equal, the increase in commodity prices may induce a similar tendency of inflation and hence become a monetary policy issue. However, the impact of the changes of commodity prices on inflation is not clear. In this paper, by using Markov-switching models we show that there is an implicit impact of commodity markets on short-term interest rates for a set of heterogeneous countries (the U.S., the Euro area, Brazil, India, Russia and South Africa) over the period from January 1999 to August 2012. Besides, the VAR models reveal that short-term interest rates respond to commodity volatility shocks whatever the country. Moreover, the linkage between commodity markets and monetary policy instruments is stronger since the recent financial crisis