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Should we perform decompressive laparotomy during severe acute pancreatitis with intra-abdominal hypertension below 25 mmHg:Only the gut knows

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World Journal of Gastrointestinal Surgery 2024年第5期16卷 1470-1473页

作者： thibault Vieille Melissa Crotet Celia Turco Paul Monasterolo Hadrien Winiszewski Gael Piton Medical Intensive Care Unit Besancon University HospitalBesancon 25000France Intensive Care Unit Vesoul HospitalVesoul 70000France Department of Digestive Surgical Oncology-Liver Transplantation Unit Besancon University HospitalBesancon 25000France Inserm UMRS-938 Centre de Recherche Saint-Antoine(CRSA)Sorbonne UniversitéParis 10041NY212France Intensive Care Unit Nord Franche Comte HospitalTrevenans 90400France

We suggest that during severe acute pancreatitis(SAP)with intra-abdominal hypertension,practitioners should consider decompressive laparotomy,even with intra-abdominal pressure(IAP)below 25 ***,in this setting,non-occlusive mesenteric ischemia(NOMI)may occur even with IAP below this cutoff and lead to transmural necrosis if abdominal perfusion pressure is not promptly *** report our experience of 18 critically ill patients with SAP having undergone decompressive laparotomy of which one third had NOMI while IAP was mostly below 25 mmHg.

关键词： Acute pancreatitis Abdominal compartment syndrome Decompressive laparotomy Mesenteric ischemia Intra-abdominal pressure Abdominal perfusion pressure

Identification of the Diffusion Coefficients of Pollutants ( N O 3 - and Mn2+) through the Walls of Concrete Tank and Vulnerability of the Stored Water Quality

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Engineering（科研） 2024年第9期16卷 246-274页

作者： Narcisse Malanda Bienvenu Ebata Ndion Christian Tathy thibault Mongo Paul Louzolokimbembe Nation School Superior Polytechnic Marien Ngouabi University Brazzaville Republic of Congo Superior Institute Architecture Town Planning Building and Public Works University of Dnis Sassou Nguesso Kintl Republic of Congo

The populations of urban centers in Congo-Brazzaville have decided to develop various methods of water storage (concrete or masonry underground tanks) for domestic use, due to shortages in the distribution of water through the public network. However, questions remain as to the physico-chemical quality of the water stored in these tanks, when these structures are built in wet and relatively polluted areas. This paper presents a model of pollutant diffusion through the cementitious matrix (concrete) of tank walls simulated at a buried reservoir. The results of the experimental and numerical simulations show that certain concrete parameters, such as porosity, permeability and diffusivity, have a significant influence on the transfer of pollutants through the concrete walls, thus altering the physico-chemical quality of the stored water. The numerical models (1D) used to predict pollutant transfer and the quality of the stored water are consistent with those of the optimal control for identifying the diffusion coefficient. Major ion concentrations appear to be correlated with system porosity and diffusion coefficient. Nevertheless, the identification of the diffusion coefficient from the optimal control method, based on an explicit numerical resolution of a finite volume PDE for the approximation of the experiment, is not consistent with that of the optimal control method.

关键词： Buried Tank Water Concrete Modelling Optimal Control Diffusion Coefficient

Infrared-active phonons in one-dimensional materials and their spectroscopic signatures

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npj Computational Materials 2023年第1期9卷 331-337页

作者： Norma Rivano Nicola Marzari thibault Sohier Theory and Simulations of Materials(THEOS) École Polytechnique Fédérale de LausanneCH-1015 LausanneSwitzerland National Centre for Computational Design and Discovery of Novel Materials(MARVEL) École Polytechnique Fédérale de LausanneCH-1015 LausanneSwitzerland Laboratory for Materials Simulations Paul Scherrer Institut5232 Villigen PSISwitzerland Laboratoire Charles Coulomb(L2C) Universitéde MontpellierCNRSMontpellierFrance

Dimensionality provides a clear fingerprint on the dispersion of infrared-active,polar-optical *** these phonons,the local dipoles parametrized by the Born effective charges drive the LO-TO splitting of bulk materials;this splitting actually breaks down in two-dimensional ***,we develop the theory for one-dimensional(1D)systems—nanowires,nanotubes,and atomic and polymeric *** an analytical model with the implementation of density-functional perturbation theory in 1D boundary conditions,we show that the dielectric splitting in the dispersion relations collapses as x^(2) log(x)at the zone *** dielectric properties and the radius of the 1D materials are linked by the present work to these red shifts,opening infrared and Raman characterization avenues.

关键词： dimensional splitting dielectric

Safe-event pruning in spacecraft conjunction management

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Astrodynamics 2023年第4期7卷 401-413页

作者： Sébastien Henry Roberto Armellin thibault Gateau Guggenheim School of Aerospace Engineering Georgia Institute of TechnologyAtlantaGA 30332USA Te Punaha Atea-Space Institute The University of AucklandAuckland 1010New Zealand Department of Aerospace Vehicles Design and Control Institut Superieur de I'Aeronautique et de I'EspaceToulouse 31055France

Spacecraft conjunction management plays a crucial role in the mitigation of space *** a conjunction event occurs,resources and time are spent analyzing,planning,and potentially maneuvering the *** work contributes to a subpart of the problem:Confidently identifying events that will not lead to a high collision probability,and therefore do not require further *** method reduces the dimensionality of the data via principal component analysis(PCA)on a subset of ***-risk regions are then determined by clustering the projected data,and events that do not belong to a high-risk cluster are pruned.A genetic algorithm(GA)is developed to optimize the number of clusters and feature selection of the ***,an ensemble learning framework is proposed to combine the suboptimal models for better *** results show that the first set of parameters pruned approximately 50%of the events in the testing set with no false negatives,whereas the second set of parameters pruned 70%of the events and maintained a near-perfect *** results could benefit the optimization of operational resources and allow operators to focus better on the events of interest.

关键词： space situational awareness collision avoidance genetic algorithm(GA) ensemble learning

High Order Schemes on Three-Dimensional General Polyhedral Meshes—Application to the Level Set Method

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Communications in Computational Physics 2012年第6期12卷 1-41页

作者： thibault Pringuey R.Stewart Cant CFD Laboratory Department of EngineeringUniversity of CambridgeTrumpington StreetCambridge CB21PZUK

In this article,we detail the methodology developed to construct arbitrarily high order schemes—linear and WENO—on 3D mixed-element unstructured meshes made up of general convex polyhedral *** approach is tailored specifically for the solution of scalar level set equations for application to incompressible two-phase flow *** construction of WENO schemes on 3D unstructured meshes is notoriously difficult,as it involves a much higher level of complexity than 2D *** due to the multiplicity of geometrical considerations introduced by the extra dimension,especially on mixed-element ***,we have specifically developed a number of algorithms to handle mixed-element meshes composed of convex polyhedra with convex polygonal *** contribution of this work concerns several areas of interest:the formulation of an improved methodology in 3D,the minimisation of computational runtime in the implementation through the maximum use of pre-processing operations,the generation of novel methods to handle complex 3D mixed-element meshes and finally the application of the method to the transport of a scalar level set.

关键词： WENO scheme three-dimensional unstructured mesh mixed element polyhedral element hyperbolic equations level set

Robust Conservative Level SetMethod for 3D Mixed-Element Meshes —Application to LES of Primary Liquid-Sheet Breakup

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Communications in Computational Physics 2014年第7期16卷 403-439页

作者： thibault Pringuey R.Stewart Cant CFD Laboratory Department of EngineeringUniversity of CambridgeUK.

In this article we detail the methodology developed to construct an efficient interface description technique—the robust conservative level set(RCLS)—to simulate multiphase flows on mixed-element unstructured meshes while conserving mass to machine *** approach is tailored specifically for industry as the three-dimensional unstructured approach allows for the treatment of very complex *** addition,special care has been taken to optimise the trade-off between accuracy and computational cost while maintaining the robustness of the numerical *** was achieved by solving the transport equations for the liquid volume fraction using a WENO scheme for polyhedral meshes and by adding a flux-limiter *** performance of the resulting method has been compared against established multiphase numerical methods and its ability to capture the physics of multiphase flows is demonstrated on a range of relevant test ***,the RCLS method has been applied to the simulation of the primary breakup of a flat liquid sheet of kerosene in co-flowing high-pressure *** quasi-DNS/LES computation was performed at relevant aero-engine conditions on a three-dimensional mixed-element unstructured *** numerical results have been validated qualitatively against theoretical predictions and experimental *** particular,the expected breakup regime was observed in the simulation ***,the computation reproduced faithfully the breakup length predicted by a correlation based on experimental *** constitutes a first step towards a quantitative validation.

关键词： Multiphase flow level set method flux limiter MULES WENO scheme threedimensional unstructured mesh mixed element conservative method atomisation primary breakup flat sheet breakup

High-performance laser power feedback control system for cold atom physics

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Chinese Optics Letters 2011年第9期9卷 42-44页

作者：鹿博 thibault Vogt 刘新星周小计陈徐宗 School of Electronics Engineering and Computer Science Peking University

A laser power feedback control system that features fast response, large-scale performance, low noise, and excellent stability is presented. Some essential points used for optimization are described. Primary optical lattice experiments are given as examples to show the performance of this system. With these performance characteristics, the power control system is useful for applications in cold atom physics and precision measurements.

关键词： Adaptive control systems Feedback control

Reinforcement learning building control approach harnessing imitation learning

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Energy and AI 2023年第4期14卷 60-72页

作者： Sourav Dey thibault Marzullo Xiangyu Zhang Gregor Henze Department of Civil Environmental and Architectural EngineeringUniversity of ColoradoBoulderCOUSA National Renewable Energy Laboratory GoldenCOUSA Renewable and Sustainable Energy Institute BoulderCOUSA

Reinforcement learning(RL)has shown significant success in sequential decision making in fields like autonomous vehicles,robotics,marketing and gaming *** success has attracted the attention to the RL control approach for building energy systems which are becoming complicated due to the need to optimize for multiple,potentially conflicting,goals like occupant comfort,energy use and grid ***,for real world applications,RL has several drawbacks like requiring large training data and time,and unstable control behavior during the early exploration process making it infeasible for an application directly to building control *** address these issues,an imitation learning approach is utilized herein where the RL agents starts with a policy transferred from accepted rule based policies and heuristic *** approach is successful in reducing the training time,preventing the unstable early exploration behavior and improving upon an accepted rule-based policy-all of these make RL a more practical control approach for real world applications in the domain of building controls.

关键词： Reinforcement learning Building controls Imitation learning Artificial intelligence

A Concept of Dynamically Reconfigurable Real-time Vision System for Autonomous Mobile Robotics

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International Journal of Automation and computing 2008年第2期5卷 174-184页

作者： Aymeric De Cabrol thibault Garcia Patrick Bonnin Maryline Chetto L2TI Université Paris 1399 avenue JB Clément93 430 Villetaneuse IRCCyN 1 rue de la No■BP 92 10144321 Nantes CEDEX 03

This paper describes specific constraints of vision systems that are dedicated to be embedded in mobile robots. If PC-based hardware architecture is convenient in this field because of its versatility, flexibility, performance, and cost, current real-time operating systems are not completely adapted to long processing with varying duration, and it is often necessary to oversize the system to guarantee fail-safe functioning. Also, interactions with other robotic tasks having more priority are difficult to handle. To answer this problem, we have developed a dynamically reconfigurable vision processing system, based on the innovative features of Cleopatre real-time applicative layer concerning scheduling and fault tolerance. This framework allows to define emergency and optional tasks to ensure a minimal quality of service for the other subsystems of the robot, while allowing to adapt dynamically vision processing chain to an exceptional overlasting vision process or processor overload. Thus, it allows a better cohabitation of several subsystems in a single hardware, and to develop less expensive but safe systems, as they will be designed for the regular case and not rare exceptional ones. Finally, it brings a new way to think and develop vision systems, with pairs of complementary operators.

关键词： Real-time vision dynamic reconfiguration embedded systems robustness real-time operating system