When the profile information of an existing road is missing or not up-to-date and the parameters of the vertical alignment are needed for engineering analysis, the engineer has to recreate the geometric design features of the road alignment using collected profile data. The profile data may be collected using traditional surveying methods, global positioning systems, or digital imagery. This pa...

Rotor profile is a critical factor affecting the performance of Roots vacuum pumps. Hence, research on rotor profiles pumps important. The are mainly composed arcs, involutes, cycloids, epicycloid, and combined curves. Moreover, two form pair conjugate To obtain parabolic profile, transformations three coordinate systems established to derive equations analyze curve its curve. Additionally, par...

A cubic Bézier-profile plate for multimodal vibration energy harvesting was developed. The design of the based on an optimization procedure in which profile optimized via parameters a Bézier curve to meet requirements. exploited its first bending mode and twisting mode. conversion into electrical by electromagnetic induction with magnet attached corner plate. These two closely spaced modes achi...

A new algorithm for approximation of a given surface or scattered points by a surface of revolution is presented. It forms the basis for a study of approximation with profile surfaces. Those are sweeping surfaces traced out by a planar curve when its plane is rolling on a developable surface. Important special cases include developable surfaces and pipe surfaces, where the moving curve is a str...

This paper proposes an off-line feedrate scheduling method of CNC machines constrained by chord tolerance, acceleration and jerk limitations. The off-line process for curve scanning and feedrate scheduling is realized as a pre-processor, which releases the computational burden in real-time task. The proposed method first scans a non-uniform rational B-spline (NURBS) curve and finds out the cruc...

In practical machining, the multi-axis actual dynamic performances don’t match well, which reduces the profile precision greatly. The computer numerical control (CNC) machine tools contour error coupled-control strategy based on line interpolation and curve interpolation is developed in the paper. After analyze the conventional CNC contour error control scheme, put forward the contour error cou...

We report a detailed multi-frequency study of significant instabilities observed in the average pulse profile of the 16-millisecond pulsar PSR J1022+1001. These unusual profile variations which are seen as a function of time and of radio frequency are clearly different from classical profile mode-changing. We also note discrete jumps in the polarisation position angle curve of this pulsar which...