Requirements for the respect of the environment encourage to reduce the impact of human activity on the nature. Civil engineering answers these requirements by the development of ecological construction materials. Thi...Requirements for the respect of the environment encourage to reduce the impact of human activity on the nature. Civil engineering answers these requirements by the development of ecological construction materials. This paper deals with the transformation of clay raw materials which enable the processing of environmentally friendly construction materials: in addition to their biodegradability, the alveolar fired clay materials allow energy saving in home heating thanks to their thermal isolation properties. But their manufacturing is a high energy consumption process, in particular during compaction, drying and firing which contribute to the emission of greenhouse gases. The goal of this paper is to study the rheology of clay pastes in order to develop low energy in manufacturing processes. For this purpose, theoretical and experimental approaches were carried out on six clay varieties. In the theoretical approach, a finite element (FE) simulation model has been developed for pressing a non-rigid material predicting deformations and stresses occurring within the clay structure. Experiments have then been carried out to validate the finite element modelling. In this experimental approach, the clay pastes were transformed with water content respecting the Atterberg limits which determine the plasticity of clays. The samples compaction has been carried out under variable loadings in order to determine the suitable low energy consumption loading.展开更多
Recently,sparse representation classification(SRC)and fisher discrimination dictionary learning(FDDL)methods have emerged as important methods for vehicle classification.In this paper,inspired by recent breakthroughs ...Recently,sparse representation classification(SRC)and fisher discrimination dictionary learning(FDDL)methods have emerged as important methods for vehicle classification.In this paper,inspired by recent breakthroughs of discrimination dictionary learning approach and multi-task joint covariate selection,we focus on the problem of vehicle classification in real-world applications by formulating it as a multi-task joint sparse representation model based on fisher discrimination dictionary learning to merge the strength of multiple features among multiple sensors.To improve the classification accuracy in complex scenes,we develop a new method,called multi-task joint sparse representation classification based on fisher discrimination dictionary learning,for vehicle classification.In our proposed method,the acoustic and seismic sensor data sets are captured to measure the same physical event simultaneously by multiple heterogeneous sensors and the multi-dimensional frequency spectrum features of sensors data are extracted using Mel frequency cepstral coefficients(MFCC).Moreover,we extend our model to handle sparse environmental noise.We experimentally demonstrate the benefits of joint information fusion based on fisher discrimination dictionary learning from different sensors in vehicle classification tasks.展开更多
The integration of additive manufacturing(AM)in design and engineering has prompted a wide spectrum of research efforts,involving topologically optimized solid/lattice structures,multimaterial structures,bioinspired o...The integration of additive manufacturing(AM)in design and engineering has prompted a wide spectrum of research efforts,involving topologically optimized solid/lattice structures,multimaterial structures,bioinspired organic structures,and multiscale structures,to name a few.However,except for obvious cases,very little attention has been given to the design and printing of more complex three-dimensional(3D)hollow structures or folded/creased structures.One of the main reasons is that such complex open or closed 3D cavities and regular/freeform folds generally lead to printing difficulties from support-structure-related issues.To address this barrier,this paper aims to investigate four-dimensional(4D)printing as well as origami-based design as an original research direction to design and build 3D support-free hollow structures.This work consists of describing the rough 3D hollow structures in terms of two-dimensional(2D)printed origami precursor layouts without any support structure.Such origami-based definitions are then embodied with folding functions that can be actuated and fulfilled by 3D printed smart materials.The desired 3D shape is then built once an external stimulus is applied to the active materials,therefore ensuring the transformation of the 2D origami layout to 3D structures.To demonstrate the relevance of the proposal,some illustrative cases are introduced.展开更多
In order to help companies to improve their competetiveness, it is important to develop new design methodologies. In this framework, a Functional And Robust Design (FARD) methodology dedicated to routine design of “h...In order to help companies to improve their competetiveness, it is important to develop new design methodologies. In this framework, a Functional And Robust Design (FARD) methodology dedicated to routine design of “highly productive” modular product ranges is proposed including principles of functional analysis, Design For Assembly (DFA), and techniques of modelling and simulation for ergonomics consideration. This paper focuses on the application of this original method applied to mechanical vibration and ergonomics problems of a scraper. Including biomechanical aspect in the design methodology, it is possible to identify the impact of a vibration tool on its users using numerical models of the tool coupled to a finite element model of the human hand. This method can proactively warn very early, in the design process, the risks of causing musculoskeletal disorders and facilitate an optimization of the mechanical tool. This study is a first step in a context of human-centered design.展开更多
文摘Requirements for the respect of the environment encourage to reduce the impact of human activity on the nature. Civil engineering answers these requirements by the development of ecological construction materials. This paper deals with the transformation of clay raw materials which enable the processing of environmentally friendly construction materials: in addition to their biodegradability, the alveolar fired clay materials allow energy saving in home heating thanks to their thermal isolation properties. But their manufacturing is a high energy consumption process, in particular during compaction, drying and firing which contribute to the emission of greenhouse gases. The goal of this paper is to study the rheology of clay pastes in order to develop low energy in manufacturing processes. For this purpose, theoretical and experimental approaches were carried out on six clay varieties. In the theoretical approach, a finite element (FE) simulation model has been developed for pressing a non-rigid material predicting deformations and stresses occurring within the clay structure. Experiments have then been carried out to validate the finite element modelling. In this experimental approach, the clay pastes were transformed with water content respecting the Atterberg limits which determine the plasticity of clays. The samples compaction has been carried out under variable loadings in order to determine the suitable low energy consumption loading.
基金This work was supported by National Natural Science Foundation of China(NSFC)under Grant No.61771299,No.61771322,No.61375015,No.61301027.
文摘Recently,sparse representation classification(SRC)and fisher discrimination dictionary learning(FDDL)methods have emerged as important methods for vehicle classification.In this paper,inspired by recent breakthroughs of discrimination dictionary learning approach and multi-task joint covariate selection,we focus on the problem of vehicle classification in real-world applications by formulating it as a multi-task joint sparse representation model based on fisher discrimination dictionary learning to merge the strength of multiple features among multiple sensors.To improve the classification accuracy in complex scenes,we develop a new method,called multi-task joint sparse representation classification based on fisher discrimination dictionary learning,for vehicle classification.In our proposed method,the acoustic and seismic sensor data sets are captured to measure the same physical event simultaneously by multiple heterogeneous sensors and the multi-dimensional frequency spectrum features of sensors data are extracted using Mel frequency cepstral coefficients(MFCC).Moreover,we extend our model to handle sparse environmental noise.We experimentally demonstrate the benefits of joint information fusion based on fisher discrimination dictionary learning from different sensors in vehicle classification tasks.
基金the Ministère de l’Enseignement Supérieur et de la Recherche, the French ‘Investissements d’Avenir’ program, project ISITE-BFC (contract ANR-15-IDEX-0003)China Scholarship Council as the main financial supports of this research program
文摘The integration of additive manufacturing(AM)in design and engineering has prompted a wide spectrum of research efforts,involving topologically optimized solid/lattice structures,multimaterial structures,bioinspired organic structures,and multiscale structures,to name a few.However,except for obvious cases,very little attention has been given to the design and printing of more complex three-dimensional(3D)hollow structures or folded/creased structures.One of the main reasons is that such complex open or closed 3D cavities and regular/freeform folds generally lead to printing difficulties from support-structure-related issues.To address this barrier,this paper aims to investigate four-dimensional(4D)printing as well as origami-based design as an original research direction to design and build 3D support-free hollow structures.This work consists of describing the rough 3D hollow structures in terms of two-dimensional(2D)printed origami precursor layouts without any support structure.Such origami-based definitions are then embodied with folding functions that can be actuated and fulfilled by 3D printed smart materials.The desired 3D shape is then built once an external stimulus is applied to the active materials,therefore ensuring the transformation of the 2D origami layout to 3D structures.To demonstrate the relevance of the proposal,some illustrative cases are introduced.
文摘In order to help companies to improve their competetiveness, it is important to develop new design methodologies. In this framework, a Functional And Robust Design (FARD) methodology dedicated to routine design of “highly productive” modular product ranges is proposed including principles of functional analysis, Design For Assembly (DFA), and techniques of modelling and simulation for ergonomics consideration. This paper focuses on the application of this original method applied to mechanical vibration and ergonomics problems of a scraper. Including biomechanical aspect in the design methodology, it is possible to identify the impact of a vibration tool on its users using numerical models of the tool coupled to a finite element model of the human hand. This method can proactively warn very early, in the design process, the risks of causing musculoskeletal disorders and facilitate an optimization of the mechanical tool. This study is a first step in a context of human-centered design.
