Ecole polytechnique

Brussels, Belgium

Ecole polytechnique

Brussels, Belgium
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Grant
Agency: European Commission | Branch: H2020 | Program: MSCA-RISE | Phase: MSCA-RISE-2015 | Award Amount: 1.62M | Year: 2016

According to UNEP, the building sector is estimated to be worth 10% of the global GDP and employs 111 million people. In addition, buildings use about 40% of global energy, 40% of global resources and emit approximately 33% of global GHG emissions. Finally, the fact that people today spend, on average, more than 80% of their time indoors, enhances its social importance. All above indicate the necessity to optimize building design. Architects usually name optimal design the choice among a very limited set of design alternatives, dictated by their experience and intuition. However, modern design of structures requires one to account for a great number of criteria deriving from multiple disciplines, often of conflicting nature. The vast number of alternative choices enhances the possibility of arriving at an optimum with the incorporation of smart, automatic tools in the design process, further guiding designers intuition. The principal aim of the proposed Network is to create and test methodologies for the application of optimization techniques in different design phases of civil structures by developing strong synergies among a multi-disciplinary team of academic experts from Greece, France, Cyprus, Canada, Turkey, Egypt & Jordan and SMEs from France & Greece. A first goal of the project is to exploit the use of shape and topology optimization techniques in computer aided architectural design. Moreover, the Network wants to exchange ideas, propose formulations that correspond to real-life applications and develop solutions for optimal multi-disciplinary architectural design. Of particular interest is the combination of criteria deriving from structural mechanics, eco-design, bioclimatic design and acoustic performance. For each topic, joint workshops, seminars and long-term visits will be organized at the coordinating and partner institutions. The results will be published in scientific journals, professional magazines and presented in international conferences.


Grant
Agency: European Commission | Branch: H2020 | Program: MSCA-RISE | Phase: MSCA-RISE-2014 | Award Amount: 742.50K | Year: 2014

Our project aims to fill the gap between flexible electronic technology and design by developing highly predictive, generic, open-source, design-oriented organic and oxide based TFT compact model libraries, to be integrated in commercial Electron Design Automation (EDA) environments for full large area low cost circuit design for novel applications. These model libraries will be released together with parameter extraction standard templates to assist in the fast transfer between initial prototype device measurements to full product design. Such a facility will open the opportunity for wide flexible electronics design


Grant
Agency: European Commission | Branch: FP7 | Program: ERC-SyG | Phase: ERC-2012-SyG | Award Amount: 9.97M | Year: 2013

The overarching goal of the present proposal is to exploit materials design, coherent optical methods and multiple theoretical approaches to deterministically control ordered states of strongly correlated electron materials, also referred to as quantum or complex materials. The underlying ideas can be applied to vast number of problems in materials physics, but the stated goal is that of optimizing superconductivity at higher temperatures than achieved so far, possibly even at room temperature. The proposal starts from research strands that follow challenging but well-establish paths, such as the use of complex-oxide heterostructures and strain engineering at interfaces to modulate the electronic properties. In a second class of investigations, coherent optical control of lattice dynamics with strong field THz transients is proposed to anneal the competing order quenching superconductivity. This builds on our recent discovery of light-induced transient superconductivity in high temperature cuprates, a remarkable process not yet understood or optimized. We will use a combination of femtosecond optical and x-ray experiments with Free Electron Lasers, together with time dependent real-materials simulations. Perhaps the most ambitious goal will be to develop laser-cooling techniques to reduce quantum phase fluctuations between planes of cuprate superconductors. Finally, we propose to use static and dynamic techniques to engineer new phases of condensed matter, for example by engineering new materials with a single band crossing the Fermi level, to optimize superconductivity. A unique combination of complementary expertise, from materials design, to coherent and ultrafast optical and x-ray physics, with materials and quantum optics theory, will be key in making true progress in these areas.


Grant
Agency: European Commission | Branch: FP7 | Program: ERC-CG | Phase: ERC-CG-2013-PE3 | Award Amount: 1.71M | Year: 2014

Materials with strong electronic Coulomb correlations present unique electronic properties such as exotic magnetism, charge or orbital order, or unconventional optical or transport properties, including superconductivity, thermoelectricity or metal-insulator transitions. The concerted behavior of the electrons in these ``correlated materials moreover leads to an extreme sensitivity to external stimuli such as changes in temperature, pressure, or external fields. This tuneability of even fundamental properties is both a harbinger for technological applications and a challenge to currently available theoretical methods: Indeed, these properties are the result of strong electron-electron interactions and subtle quantum correlations, and cannot be understood without a proper description of excited states. The aim of the present project is to elaborate, implement and test new approaches to investigate the spectral and optical properties of correlated materials ``from first principles, that is, without adjustable parameters. I will build on the success of state-of-the-art dynamical mean field-based electronic structure techniques, but aim at developing them into truly first-principles methods, where a full treatment of the long-range Coulomb interactions replaces the current practice of purely local Hubbard interaction parameters. My target materials are among the most interesting for modern technologies, such as transition metal oxides (with potential applications ranging from oxide electronics to battery materials) and rare earth compounds used as environmentally-responsible pigments. Establishing first-principles techniques with truly predictive power for these classes of materials will bring us closer to the final goal of tailoring correlated materials with preassigned properties.


Grant
Agency: European Commission | Branch: H2020 | Program: MSCA-IF-GF | Phase: MSCA-IF-2014-GF | Award Amount: 264.67K | Year: 2015

Observations of solar wind (SW) turbulence have usually emphasized magnetohydrodynamic (MHD) scales where the Kolmogorov scaling f 5/3 of the magnetic spectra is frequently observed. These spectra are thought to result from strongly nonlinear interactions. However, the question as to how turbulence of the MHD scales terminates its cascade at smaller (kinetic) scales is still hotly debated. Answering this question is indeed fundamental to understanding the processes of particle acceleration and plasma heating in the SW and in other astrophysical plasmas. This project aims at studying the mechanisms of energy dissipation in solar wind. We will use a innovative multiple approach that combines in-situ fields and particles data available from the multispacecraft missions, numerical simulations and theories to model the complex behavior of turbulence cascade at kinetic scales where it is dissipated.


Grant
Agency: European Commission | Branch: FP7 | Program: ERC-AG | Phase: ERC-AG-PE1 | Award Amount: 1.87M | Year: 2013

Reliable techniques in finance should take into account the unavoidable modelling error. This is the main focus of this project that we intend to address from two viewpoints raising new questions in applied mathematics. Our first research direction is to device robust risk management methods which use the market observations and the no-arbitrage principle. A classical result in financial mathematics essentially states that, in idealized frictionless financial markets, the price processes of tradable securities must be a martingale under some equivalent probability measure. We propose to adopt a conservative viewpoint by deriving the bounds over all possible choices of martingales. By accounting for the rich information corresponding to the prices of European call options, we arrive naturally to a new optimal transportation problem. We intend to analyze several questions: clarify the connection with the Skorohod embedding problem, understand better the duality, develop the corresponding numerical techniques, explore the robust portfolio optimization problems under such constraints, and understand their impact on the risk measurement. The second direction of research proposed in this project concerns the recent theory of Mean Field Games, recently introduced by Lasry and Lions. Our intention is to address this theory from the probabilistic point of view. The main observation is that the MFG equations, consisting of a coupled system of a Fokker-Planck equation and a semilinear Hamilton-Jacobi-Bellman equation, can be viewed as an extension of the theory of forward-backward stochastic differential equations (FBSDE) with mean-field dependence. This theory provides a simple modelling of the interactions which may be used to explain important phenomena on financial markets as the contagion effect and the systemic risk. In particular, the connection with FBSDEs opens the door to probabilistic numerical methods.


Grant
Agency: European Commission | Branch: H2020 | Program: ERC-STG | Phase: ERC-2016-STG | Award Amount: 1.50M | Year: 2017

Bacteria are tiny; yet their collective dynamics generate large-scale flows and profoundly modify a fluids viscosity or diffusivity. So do autophoretic microswimmers, an example of active microscopic particles that draw their motion from physico-chemical exchanges with their environment. How do such ``active fluids turn individual microscopic propulsion into macroscopic fluid dynamics? What controls this self-organization process? These are fundamental questions for biologists but also for engineers, to use these suspensions for mixing or chemical sensing and, more generally, for creating active fluids whose macroscopic physical properties can be controlled precisely. Self-propulsion of autophoretic swimmers was reported only recently. Major scientific gaps impair the quantitative understanding of their individual and collective dynamics, which is required to exploit these active fluids. Existing models scarcely account for important experimental characteristics such as complex hydrodynamics, physico-chemical processes and confinement. Thus, these models cannot yet be used as predictive tools, even at the individual level. Further, to use phoretic suspensions as active fluids with microscopically-controlled properties, quantitatively-predictive models are needed for the collective dynamics. Instead of ad-hoc interaction rules, collective models must be built on a detailed physico-mechanical description of each swimmers interaction with its environment. This project will develop these tools and validate them against experimental data. This requires overcoming several major challenges: the diversity of electro-chemical processes, the confined geometry, the large number of particles, and the plurality of interaction mechanisms and their nonlinear coupling. To address these issues, rigorous physical, mathematical and numerical models will be developed to obtain a complete multi-scale description of the individual and collective dynamics of active particles.


Grant
Agency: European Commission | Branch: H2020 | Program: ERC-STG | Phase: ERC-2016-STG | Award Amount: 1.50M | Year: 2017

As we push the frontier of particle physics to higher particle energies, conventional accelerator techniques are attaining their limits and new concepts are emerging. The use of an ionized gas or plasma circumvents the most significant barrier of conventional techniques by increasing the energy gained per unit length by several orders of magnitude. One class of plasma accelerators, relevant for high energy physics applications, consists in using a particle beam, the driver , to excite a plasma wave, that is then used to accelerate the main particle beam. Research in this field requires large facilities, due to stringent conditions on the driver. In the M-PAC project, I propose to power plasma accelerators with laser-accelerated electron beams based on 100-TW-class laser systems, so as to miniaturize the so-called beam-driven plasma accelerators. The project crosses the boundary of the fields of research of laser acceleration and of beam-driven plasma acceleration. With these innovative miniature versions, the goal of the M-PAC project is then to tackle, through experiments and simulations, the next Grand Challenges facing the field of beam-driven plasma acceleration, bringing plasma accelerator technology to viability for high energy physics collider applications. They include the generation and preservation of the excellent beam quality required for high-energy colliders and next-generation light sources, the demonstration of high drive-to-main-beam energy efficiency and the acceleration of the antimatter counterpart of the electron, the positron. Finally, the miniature beam-driven plasma accelerators open new opportunities to push university-scale plasma-based light sources to the next level, both in terms of brightness and spectral range.


Grant
Agency: European Commission | Branch: H2020 | Program: ERC-STG | Phase: ERC-2016-STG | Award Amount: 1.28M | Year: 2017

This project analyzes the propagation of shocks through international trade. The microeconomic structure of trade networks is argued to favor the propagation and amplification of shocks with an end-effect on the dynamics and volatility of aggregate trade. The exploitation of highly disaggregated firm-to-firm trade data offers a unique opportunity to analyze these questions into details. The first part of the proposal studies the determinants of trade networks. I build a search-and-matching framework to explain the formation of bilateral trade relationships as a matching process between individual exporters in one country and individual buyers located in another country. This framework allows explaining the structure of trade networks observed in the data, both in the cross-section and over time. The model is also used to revisit several puzzles of the international economic literature, including the question of welfare gains from trade and the convergence to the law of one price. The second part of the proposal studies the consequences of the structure of trade networks for the volatility of trade and its resilience to relative price shocks. I study how the observed connections between individual firms help propagate individual and aggregate shocks, with an end-effect on the volatility of aggregate trade and the comovement of GDPs across countries. The high concentration of trade networks and the strength of production linkages, within and across countries, help amplify the aggregate effect of individual shocks. I also analyze how the structure of trade networks shapes the response of aggregate trade to relative price shocks. The nature and history of firm-to-firm relationships is argued to have implications for the aggregate elasticity of trade.


A laser device includes an apparatus for producing amplified laser pulses, using a plurality of amplifying optical fibers, and groups the basic amplified pulses into an overall amplified pulse, as well as a target, onto which the overall amplified pulse is directed such as to generate a predetermined physical process thereon, which causes a change of state in the target. The laser device is configured to measure at least one distinctive parameter of the generated physical process; adjust at least one characteristic for adjusting the basic amplified laser pulses; and analyze a plurality of measurements for different adjustments. The device analyzes the measurements many times in loops for different laser pulse adjustment characteristics, enabling an optimization by a heuristic method. Also provided is a heuristic optimization method implemented by the laser device.

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