摘要: A low-cost and simple technique for encryption of two-dimensional patterns and shapes is suggested and demonstrated. The method is based on the superposition of random grids.关键词: Simple Lie groups Controllability Invariant vector fields Root systems ...
Through the good graces of Inga Karliner of the University of Illinois physics department I was put in contact with Ivan Petrov of the U of I's materials research department, which just happens to be a national collaborative center for materials testing, which means they have a hallway with ...
Images on paper are essentially arrangements of lines and shapes on a flat surface - symbols which make up visual language representing objects in a threedimensional world. Reading pictures is a cognitive skill and to understand a picture correctly, the viewer must know certain conventions. However...
Optical information for the shapes of surfaces is given by the ratio of azimuth to elevation. Flat surfaces such as the ground have a linear to quadratic ratio. Increase the ratio and hills are seen. Decrease it and the surrounds are a bowl. Sudden changes in the ratio indicate changes in...
They are stored as a two-dimensional array of dots, which gives them a fixed resolution. A $3\times5$-inch bitmap image that prints correctly on your 300dpi laser printer will only be a $\frac{3}{4}\times1\frac{1}{4}$-inch picture if you make your final copy on a 1200dpi ...
For centuries, people knew pure carbon in two forms, diamond and graphite. Diamond is three-dimensional matrix of carbon atoms in which each atom is bonded to four others in a tetrahedral arrangement. Graphite on the other hand consists of two-dimension sheets of hexagons, like a honeycomb, ...
We investigated the causes of asymmetries in intermodal transfer and of conclusions: (i) Transfer from vision to touch is possible under certain conditions and is facilitated by the use of two-dimensional (2-D) visual representations rather than three-dimensional (3-D) visual objects. (ii) The...
aThis is why a great number of industries are always more frequently facing the problem of nesting which is how to economically cut two-dimensional irregular shapes from a given stock sheet. An irregular polygon can have sides of any length and each interior angle can be any measure. They ca...
The two parabolic mirrors PM1 and PM2 are set face to face, as shown in Fig. 1. The shapes and focal lengths of PM1 and PM2 are the same, and PM1 and PM2 have a hole at the top and bottom, respectively. When the focal point of PM1 is at the centre of the PM2's hole and ...
The active fabrics created using LCE yarns demonstrated reversible three-dimensional shape changes by utilizing circular weaving patterns that resulted in cone shapes when heated. This seamless integration of active LCE yarns with existing passive yarns opens up new possibilities for developing stimuli-resp...