Computer-Aided Design Of Two-Dimensional Recursive Digital Filters On The Basis Of Quadrantal Symmetry

Abstract Recently, there is an increasing interest in design of circular weft jacquard because of the pursuit of fashion and comfort. Aiming at the complexity of the computer-aided design method of the existing circular weft-knitted jacquard fabrics, which is not conducive to the rapid design and intelligible for designers, a design method was proposed to transform pattern notation into knitting diagram efficiently, which was based on knitting rules and its creation as a set of jacquard modules. Knitting characteristics of jacquard fabrics were studied as a precondition. On this basis, the design procedures of jacquard modules were analyzed and illustrated by taking tricolor bird's eye backing jacquard as an example. Jacquard modules with various jacquard effects were designed and stored in a jacquard module database. To mathematically describe pattern notation, knitting diagram, and jacquard module, two-dimensional matrixes were established by the method of mathematical modeling, and a corresponding algorithm for the transformation of the pattern to knitting information according to the knitting rules of jacquard modules, which can be applied to ordinary jacquard fabrics was summarized. The project of tricolor circular weft-knitted jacquard with bird's eye in the reverse and four-color air-layer jacquard were taken for instance to verify the models and algorithm. The results obtained show that the approach can efficiently and conveniently realize the designation and machine-knitting of weft-knitted jacquard fabric, which provide a theoretical basis and notation of modeling for the computer-aided design of circular weft-knitted jacquard fabrics.

Download Full-text

Computer-Aided Sketching: Incorporating the Locus to Improve the Three-Dimensional Geometric Design

Symmetry ◽

10.3390/sym12071181 ◽

2020 ◽

Vol 12 (7) ◽

pp. 1181 ◽

Cited By ~ 1

Author(s):

José Ignacio Rojas-Sola ◽

David Hernández-Díaz ◽

Ricardo Villar-Ribera ◽

Vicente Hernández-Abad ◽

Francisco Hernández-Abad

Keyword(s):

Computational Geometry ◽

Computer Aided Design ◽

Three Dimensional ◽

Geometric Design ◽

Curved Surfaces ◽

Two Dimensional ◽

Technical Design ◽

Computer Aided ◽

Aided Design

This article presents evidence of the convenience of implementing the geometric places of the plane into commercial computer-aided design (CAD) software as auxiliary tools in the computer-aided sketching process. Additionally, the research considers the possibility of adding several intuitive spatial geometric places to improve the efficiency of the three-dimensional geometric design. For demonstrative purposes, four examples are presented. A two-dimensional figure positioned on the flat face of an object shows the significant improvement over tools currently available in commercial CAD software, both vector and parametric: it is more intuitive and does not require the designer to execute as many operations. Two more complex three-dimensional examples are presented to show how the use of spatial geometric places, implemented as CAD software functions, would be an effective and highly intuitive tool. Using these functions produces auxiliary curved surfaces with points whose notable features are a significant innovation. A final example provided solves a geometric place problem using own software designed for this purpose. The proposal to incorporate geometric places into CAD software would lead to a significant improvement in the field of computational geometry. Consequently, the incorporation of geometric places into CAD software could increase technical-design productivity by eliminating some intermediate operations, such as symmetry, among others, and improving the geometry training of less skilled users.

Download Full-text

Computational wrapping: A universal method to wrap 3D-curved surfaces with nonstretchable materials for conformal devices

Science Advances ◽

10.1126/sciadv.aax6212 ◽

2020 ◽

Vol 6 (15) ◽

pp. eaax6212 ◽

Cited By ~ 2

Author(s):

Yu-Ki Lee ◽

Zhonghua Xi ◽

Young-Joo Lee ◽

Yun-Hyeong Kim ◽

Yue Hao ◽

...

Keyword(s):

Computer Aided Design ◽

Reliable Method ◽

Design Method ◽

Universal Method ◽

Curved Surfaces ◽

Two Dimensional ◽

Steel Sheets ◽

Computer Aided ◽

Conformal Structures ◽

Aided Design

This study starts from the counterintuitive question of how we can render conventional stiff, nonstretchable, and even brittle materials sufficiently conformable to fully wrap curved surfaces, such as spheres, without failure. Here, we extend the geometrical design method of computational origami to wrapping. Our computational wrapping approach provides a robust and reliable method for fabricating conformal devices for arbitrary curved surfaces with a computationally designed nonpolyhedral developable net. This computer-aided design transforms two-dimensional (2D)–based materials, such as Si wafers and steel sheets, into various targeted conformal structures that can fully wrap desired 3D structures without fracture or severe plastic deformation. We further demonstrate that our computational wrapping approach enables a design platform that can transform conventional nonstretchable 2D-based devices, such as electroluminescent lighting and flexible batteries, into conformal 3D curved devices.

Download Full-text