ParisTech

About: ParisTech is a education organization based out in Paris, France. It is known for research contribution in the topics: Residual stress & Finite element method. The organization has 1888 authors who have published 1965 publications receiving 55532 citations. The organization is also known as: Paris Institute of Technology & ParisTech Développement.

A global approach for the design of a Rim-Driven marine turbine generator for sail boat

Abstract: Development of new ways to provide clean onboard electric energy is a key feature for the sailing boat industry and sail race teams. This is why marine turbines (MT), are considered to provide onboard energy. These turbines can be used to harness kinetic energy of the water flow related to the ship motion. In this paper we propose to study an unconventional design of such a turbine where the electrical generator is located in the periphery of the blades and where the magnetic gap is water filled. This kind of solution called “RIM DRIVEN” structure allows to increase the compactness and the robustness of the system. Due to the strong interaction of the multi physical phenomena, an electromagnetic model and a thermal model of the PM generator are associated with a hydrodynamic model of the blades and of the water flow in the underwater air gap. These models are used in a global coupled design approach in order to optimize, under constraints, the global efficiency of the system. This solution allows to optimize the system design.

Dynamic system performance of SISO, MISO and MIMO Alamouti schemes

Abstract: In this paper, the performance of a SISO system, a 2 × 1 MISO Alamouti transmission system and a 2 × N MIMO Alamouti transmission with maximum ratio combining (MRC) receiver system is studied in terms of mean flow throughput per user. A dynamic study (dynamic number of active users) is derived considering the downlink Rayleigh channel in a multi-cellular system. Two assumptions are considered: admission control based on a maximum number of users or no admission control. The studied cell is divided into concentric rings. Analytical expressions of the mean flow throughput of a user in each ring are proposed. A comparison between the performance of the different systems is presented and discussed.

A Novel Scenario-Based Bi-objective Optimization Model for Sustainable Food Supply Chain During the COVID-19: a Case Study

Abstract: Since food is one of the essential human needs, studies on this topic have always been a global concern. With the advent of COVID-19 and the emergence of many problems in all aspects of the food supply chain (such as production, transportation, distribution), this issue has become doubly important. This paper discusses an MINLP optimization model for handling the impact of the COVID-19 pandemic based on the food supply network through Food Hubs (FHs). In this research, the concept of FH has been used for a more effective and faster connection of consumers to production sites. Due to prevention of the spread of coronavirus and the quarantine conditions, the areas have been divided into two parts (high-risk and low-risk) and two scenarios have been defined for this supply chain. The purpose of this paper is to reduce costs and environmental impacts as much as possible. The proposed model is solved by GAMS software for small- and middle-size test problems, and it is solved with genetic optimization algorithm as a meta-heuristic approach for large-size problems. Also, to solve the developed linear multi-objective model, augmented ɛ-constraint approach is applied, and a real case study from Iran is examined to illustrate the validation of the proposed model. Numerical and computational results are provided to prove the efficiency and feasibility of the presented model. Finally, sensitivity analysis is presented to evaluate the effect of changing some parameters on variables and objective functions.

Ab initio Design, Experimental Validation, and Scope of Coupling Coefficients in Waveguide Arrays and Discrete Photonics Patterns

Abstract: In coupled waveguide arrays, well-defined coupling coefficients are still required to demonstrate advanced effects on a quantitative basis, especially in patterned arrays where new discrete photonics functions need accurate coupling gradients. We show that adequate arrays of strip loaded waveguides designed within an extended second-neighbor coupled-mode theory can actually be constructed by means of state-of-the-art technologies, with the necessary coupling coefficient ratios (~ 0.5) and accuracies (~ 10%). We also specify for literature systems the weak coupling regime where the conventional coupled-mode theory truly applies, and the moderate coupling regime where the extended theory is required but can be approximated by the conventional theory with an apparent coupling coefficient.

Environmental ocean and plume modeling for deep sea mining in the Bismarck Sea

Abstract: A pressing environmental question facing the ocean is the potential impact of possible deep-sea mining activities. This work presents our initial results in developing an ocean and plume modeling system for the Bismark Sea where deep sea mining operations will probably take place. We employ the MSEAS modeling system to both simulate the ocean and to downscale initial conditions from a global system (HYCOM) and tidal forcing from the global TPXO-8 Atlas. We found that at least 1.5 km resolution was needed to adequately resolve the multiscale flow fields. In St. Georges channel, the interaction between the tides, background currents, and underlying density fields increased the subtidal flows. Comparing to historical transport estimates, we showed that tidal forcing is needed to maintain the correct subtidal transport through that Channel. Comparisons with past simulations and measured currents all showed good agreement between the MSEAS hindcasts. Quantitative comparisons made between our hindcasts and independent synoptic ARGO profiles showed that the hindcasts beat persistence by 33% to 50%. These comparisons demonstrated that the MSEAS current estimates were useful for assessing plume advection. Our Lagrangian transport and coherence analyses indicate that the specific location and time of the releases can have a big impact on their dispersal. Our results suggest that ocean mining plumes can be best mitigated by managing releases in accord with such ocean modeling and Lagrangian transport forecasts. Real-time integrated mining-modeling-sampling is likely to provide the most effective mitigation strategies.