General strategy for developing finite elements of general geometric shape explained on quadrilateral folded plate structure element ensuring invariance properties is presented in this paper. The basic idea of this strategy consists in using the natural coordinate system only for defining the element geometry and performing the element integration in a mapped biunit square. For defining the app...

This project created a portable three-dimensional digitizer for computer graphics 3D modeling. It started from reviewing literature then constructed a digitizer, developed applications programs, created experiments and analyzed. The process of the machine started from reading pulse train of the arm rotation via Rotary Encoder at each joint. Next, it was processed by microcontroller and sent the...

Repeating an arbitrary sequence of RF pulses and magnetic field gradients will eventually lead to a steady-state condition in any magnetic resonance system. While numerical methods can quantify this trajectory, analytic analysis provides significantly more insight and a means for faster calculation. Recently, an analytic analysis using homogeneous coordinates was published. The current work fur...

Abstract—In this work, theoretical analysis and numerical results are given for time-reversal (TR) focus gains of polarization-varying electromagnetic fields in a rectangular resonant cavity. To demonstrate the gains in different polarization states of the static transceivers and the ones of the rotatable transceivers, the 3 dB attenuation areas of TR angle gain (AG) and AG flatness are first c...

We propose a new form of dimensional reduction that constrains dilatation instead of a component of momentum. It corresponds to replacing toroidal compactification in a Cartesian coordinate with that in the logarithm of the radius. Massive theories in de Sitter or anti de Sitter space are thus produced from massless (scale invariant) theories in one higher space or time dimension. As an example...

The perception of a three-dimensional (3-D) surface shape can be inferred from a 2-D image of two intersecting curves. Three experiments are reported in which we examined a possible method for determining the surface shape as a function of the geometry at the point of intersection. The method involves a two-step process in which the tangents to the two curves determine a skewed Cartesian coordi...

Origami geometric design is fundamental to many engineering applications of origami structures. This paper presents a new method for the design of three-dimensional (3D) origami structures suitable for engineering use. Using input point sets specified, respectively, in the x−z and y−z planes of a Cartesian coordinate system, the proposed method generates the coordinates of the vertices of a fol...

A novel framework for solving variational problems and partial differential equations for scalar and vector-valued data defined on surfaces is introduced in this paper. The key idea is to implicitly represent the surface as the level set of a higher dimensional function, and solve the surface equations in a fixed Cartesian coordinate system using this new embedding function. This thereby elimin...

We develop a method to calculate 2D spectrum of a binary image with better quality than that obtained via direct 2D-FFT. With FFT, jagged edges of objects due to coarse sampling introduce artifacts into the frequency domain, especially in the high-frequency area. With the proposed method, Radon projections of the binary image along lines at different viewing angles are calculated. Each projecti...