A usage coverage-based approach for assessing product family design

Computation techniques have provided designers with deeper understanding of the market niches that were neglected before. Usage contextual information has been studied in marketing research since the last century; however, little research in design engineering focuses on it. Therefore, in this paper, we analyzed the relations between usage context information and the design of products. A usage coverage model is established to integrate users and their expected usage scenarios into product family assessment. We map the user’s individual capacity together with a given product into the usage context space. The overlapping between the required usage and feasible usage can be measured. Based on this mechanism, several usage coverage indices are proposed to assess the compliance of a given product family to the expected set of usage scenarios to be covered. The original method is demonstrated on a scale-based product family of jigsaws in a redesign context. Constraint programming technique is applied to solve the physics-based causal loops that determine usage performances in a set-based design approach. Designers can rely on the results to eliminate redundant units in the family or modify the configuration of each product. The contribution of the paper is to provide an inter-disciplinary point of view to assessing the composition and configuration of a product family design.     

Determination by infrared absorption of the orientation of molecules in monomolecular layers

The mean orientation of molecules constituting Langmuir-Blodgett monomolecular layers was determined by infrared absorption with variable incidence transmission by polarizing the beam in the plane of incidence. The absorption calculation is completely developed for axial anisotropy layers when their thickness is small with respect to the wavelength. The experimental results show that the axis of the aliphatic chains makes an angle of 25±4° with the normal to the substratum for behenic acid layers, whereas this angle is only 8±5° for calcium behenate layers.     

Optimized surface discretization of functionally defined multi-material objects

We present in this paper an algorithm for meshing implicit surfaces based on the Delaunay triangulation of a point-set adaptively sampled on an implicit surface. To improve the quality of the resulting triangular mesh, we use at each iteration a mesh optimization algorithm with the following objectives: optimizing the connectivity, retrieving the sharp features, regularizing the triangles shapes and minimizing the approximation error. Then, we extend this algorithm in order to handle functionally defined heterogeneous object surfaces, while maintaining a good quality for the triangles’ shapes and the mesh features (geometrical sharp features and boundaries between different materials).