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Independent continuous mapping for topological optimization of frame structures

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Acta Mechanica Sinica 2006年第6期22卷 611-619页

作者： Yunkang Sui Jiazheng Du Yingqiao Guo Department of Mechanics Beijing University of Technology Beijing 100022 China Lab. GMMS University of Reims Champagne-Ardenne BP1039 51687 Reims France

Based on the Independent Continuous Mapping method （ICM）, a topological optimization model with continuous topological variables is built by introducing three filter functions for element weight, element allowable stress and element stiffness, which transform the 0-1 type discrete topological variables into continuous topological variables between 0 and 1. Two methods for the filter functions are adopted to avoid the structural singularity and recover falsely deleted elements： the weak material element method and the tiny section element method. Three criteria （no structural singularity, no violated constraints and no change of structural weight） are introduced to judge iteration convergence. These criteria allow finding an appropriate threshold by adjusting a discount factor in the iteration procedure. To improve the efficiency, the original optimization model is transformed into a dual problem according to the dual theory and solved in its dual space. By using MSC/Nastran as the structural solver and MSC/Patran as the developing platform, a topological optimization software of frame structures is accomplished. Numerical examples show that the ICM method is very efficient for the topological optimization of frame structures.

关键词： Frame structures Topological optimization ICM method Filter functions Element elimination

Adaptive Fuzzy Sliding Mode Power System Stabilizer Using Nussbaum Gain

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International Journal of Automation and computing 2013年第4期10卷 281-287页

作者： Emira Nechadi Mohamed Naguib Harmas Najib Essounbouli Abdelaziz Hamzaoui Electrical Engineering Department Ferhat Abbas University of Stif 1 Centre of Research for Science and Information Technology and Communication Laboratory Champagne Ardennes University

Power system stability is enhanced through a novel stabilizer developed around an adaptive fuzzy sliding mode approach which applies the Nussbaum gain to a nonlinear model of a single-machine infinite-bus （SMIB） and multi-machine power system stabilizer subjected to a three phase fault. The Nussbaum gain is used to avoid the positive sign constraint and the problem of controllability of the system. A comparative simulation study is presented to evaluate the achieved performance.

关键词： Multi-machine power system stabilizer adaptive fuzzy sliding mode Nussbaum gain Lyapounov stability.

Comment on:oncologic outcomes after robotic pancreatic resections are not inferior to open surgery

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Hepatobiliary Surgery and Nutrition 2021年第6期10卷 842-845页

作者： Antonio Mimmo Tullio Piardi Department of Hepatobiliary Pancreatic and Digestive Oncological SurgeryRobert DebréUniversity HospitalUniversity of Reims Champagne-ArdenneReimsFrance Research Unit Ea3797 VieFra Department of HepatobiliaryPancreatic and Digestive Oncological SurgeryRobert DebréUniversity HospitalUniversity of Reims Champagne-ArdenneReimsFrance

We read with interest the recently published article of Girgis et al.(1).The paper is a non-inferiority study regarding robotic versus open approach in the pancreatic resection for pancreatic adenocarcinoma(PDAC).The authors examined post-surgical complications,overall survival(OS)and the effect of surgical approach for the access to adjuvant chemotherapy(aCHT).According to the majority of scientific literature,aCHT improves the rate of survival in patients after resected *** a pancreatectomy,post-surgical complications limit the access to aCHT and,consequently,they reduce the OS(2).

关键词： resection chemotherapy

METHOD BASED ON DUAL-QUADRATIC PROGRAMMING FOR FRAME STRUCTURAL OPTIMIZATION WITH LARGE SCALE

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Applied Mathematics and Mechanics(English Edition) 2006年第3期27卷 383-391页

作者：隋允康杜家政郭英乔 Laboratory Numerical Simulation Center for Engineering Beijing university of Technology Beijing 100022P. R. China Laboratory Mechanics Materials & Structures University of Reims Champagne-ArdenneReimsBP103951687France

The optimality criteria （OC） method and mathematical programming （MP） were combined to found the sectional optimization model of frame structures. Different methods were adopted to deal with the different constraints. The stress constraints as local constraints were approached by zero-order approximation and transformed into movable sectional lower limits with the full stress criterion. The displacement constraints as global constraints were transformed into explicit expressions with the unit virtual load method. Thus an approximate explicit model for the sectional optimization of frame structures was built with stress and displacement constraints. To improve the resolution efficiency, the dual-quadratic programming was adopted to transform the original optimization model into a dual problem according to the dual theory and solved iteratively in its dual space. A method called approximate scaling step was adopted to reduce computations and smooth the iterative process. Negative constraints were deleted to reduce the size of the optimization model. With MSC/Nastran software as structural solver and MSC/Patran software as developing platform, the sectional optimization software of frame structures was accomplished, considering stress and displacement constraints. The examples show that the efficiency and accuracy are improved.

关键词： frame structures sectional optimization dual-quadratic programming approximate scaling step deletion of negative constraints

Dimensions of the Internationalization-Performance Relationship： Applied to Euronext 1 O0 Multinationals

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Management Studies 2014年第1期2卷 10-20页

作者： Samia Belaounia Mehdi Nekhili Neoma Business School Mont-Saint Aignan France university of reims champagne ardennes Reims France Neoma Business School Mont-Saint-Aignan France

In spite of the extensive literature regarding the relationship between corporate internationalization and performance, questions still remain due to conflicting empirical results. Is this due to the diversity of the conceptualization of international profile？ The results of statistical non-parametric tests obtained from a sample of 68 Euronext 100 companies over the period 2005-2009 point to a different relationship, between internationalization and performance, depending on whether the extent of international activities or their dispersion is considered.

关键词： internationalization performance multinationals Euronext

Effect of Recycling Cycles on the Mechanical and Damping Properties of Short Alfa Fibre Reinforced Polypropylene Composite

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Journal of Renewable Materials 2019年第3期7卷 253-267页

作者： Fatima Ezzahra El Abbassi Mustapha Assarar Rezak Ayad Hamid Sabhi Stephane Buet Nouzha Lamdouar Department of Civil Engineering University of Cadi AyyadMorocco Laboratory of Engineering and Material Sciences University of Reims Champagne-ArdenneFrance Laboratory of Simulation Instrumentation and MeasurementUniversity of Mohammed VMorocco

This paper aims at studying the effect of recycling on the static and dynamic properties of short alfa fibre reinforced *** this purpose,alfa fibres reinforced composites were elaborated by an injection moulding process and were subjected to different mechanical recycling ***,non-recycled and recycled materials were subjected to static tests and Dynamic Mechanical Analysis(DMA)to evaluate the effect of recycling on their ***,the effects of alkali and salt water treatments on the static and dynamic properties of the alfa composite were also *** obtained results show that tensile and flexural properties of alfa fibres reinforced composites decrease during recycling ***,the recycling induces a drop in the storage modulus and enhances the loss factor of these *** composites with alfa fibre especially the alkali treated composite show the same resistance to recycling as composites with hemp ***,SEM observations indicate a decrease in the fibres dimension with the recycling cycles,especially for alfa fibres,which can explain the decrease in the properties of the alfa composite during recycling operations.

关键词： Alfa fibre hemp fibre eco-composites recycling mechanical properties dynamic properties

DEREPLICATION STRATEGIES IN NATURAL PRODUCT RESEARCH: VARIOUS TOOLS AND METHODOLOGIES BEHIND THE SAME CONCEPT

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World Journal of Traditional Chinese Medicine 2015年第4期1卷 75-76页

作者： Jean-Hugues Renault Institut of Molecular Chemistry of reims University of Reims Champagne-Ardenne

The developmernt of new therapeutic drugs will certainly benefit from an ever improving knowledge and understanding of the living beings ***,the identification of innovative’drugable’molecules within the immense bio... 详细信息

关键词： immense innovative investments biodiversity forests oceans overview replication benefit currently

Thermal comfort of Frail People under dynamic and non-uniform thermal environments using a thermal manikin with thermoregulatory control:An experimental study

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Energy and Built Environment 2023年第4期4卷 477-491页

作者： Zoubayre El akili Youcef Bouzidi Abdelatif Merabtine Guillaume Polidori Julien Kauffmann Interdisciplinary research on Society-Technology-Environment interactions.university of Technology of Troyes TroyesFrance EPF School of Engineering.Rosières-Prés-Troyes France MATIM Faculty of Exact and Natural Sciences.University of Reims Champagne Ardenne.ReimsFrance

The thermal comfort of frail people has to be considered carefully,mainly because of the high thermal sensitivity of this population and the negative influences that unsatisfactory thermal conditions have on their *** existing thermal comfort works have been conducted under steady-state,uniform thermal environments,with far fewer being performed in dynamic and non-uniform thermal environments,and even less for frail *** study aimed at assessing the thermal responses of frail people under transient and non-uniform thermal environments,using a thermal manikin and a climatic test *** responses were investigated and discussed in both *** analysis of variance showed a significant difference in thermal comfort and thermal sensation between females and males over time,under hot *** cold exposure,results showed a significant difference in thermal sensation between females and males over time,but no significant difference was observed in term of thermal *** revealed also significant differences in the dynamic thermal sensation between the sexes under cold exposure,while results confirmed that there is no significant difference in the dynamic thermal sensation between sexes under hot exposure.

关键词： Building Energy conservation Thermal comfort Thermal sensation Thermal manikin

Adaptive Type-2 Fuzzy Sliding Mode Controller for SISO Nonlinear Systems Subject to Actuator Faults

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International Journal of Automation and computing 2013年第4期10卷 335-342页

作者： Meriem Benbrahim Najib Essounbouli Abdelaziz Hamzaoui Ammar Betta Research Center on Science and Technology of Information and Communication University of Reims Champagne Ardenne university Institute of Technology of Troyes Troyes F10026 France university of Hadj Lakhdar Batna Boukhlouf Med Elhadi StreetBatna 05000 Algeria

In this paper, an adaptive type-2 fuzzy sliding mode control to tolerate actuator faults of unknown nonlinear systems with external disturbances is presented. Based on a redundant actuation structure, a novel type-2 adaptive fuzzy fault tolerant control scheme is proposed using sliding mode control. Two adaptive type-2 fuzzy logic systems are used to approximate the unknown functions, whose adaptation laws are deduced from the stability analysis. The proposed approach allows to ensure good tracking performance despite the presence of actuator failures and external disturbances, as illustrated through a simulation example.

关键词： Type-2 fuzzy systems fault tolerant control sliding mode control adaptive system actuator faults.