The geometry of natural branching systems generally reflects functional optimization. A common property is that their bifurcations are planar and that daughter segments do not turn back in the direction of the parent segment. The present study investigates whether this also applies to bifurcations in 3D dendritic arborizations. This question was earlier addressed in a first study of flatness of...

Absolute flatness of three silicon plane mirrors have been measured by a three-intersection method based on the three-flat method using a near-infrared interferometer. The interferometer was constructed using a near-infrared laser diode with a 1,310-nm wavelength light where the silicon plane mirror is transparent. The height differences at the coordinate values between the absolute line profil...

We propose a simple version of chaotic inflation which leads to a division of the universe into infinitely many open universes with all possible values of Ω from 1 to 0. 1 E-mail: [email protected] Flatness of the universe (Ω = 1) for a long time has been considered as one of the most definite predictions of the inflationary theory. However, what will happen if ten years from now it wi...

We study the control problem of an aerial vehicle moving in the 3D space and connected to an independently moving platform through a physical link (e.g., a cable, a chain or a rope). The link is attached to the moving platform by means of a passive winch. The latter differs from an active winch by producing only a constant uncontrollable torque. We solve the problem of exact tracking of the 3D ...

manufacturing of an optical lenses demand a specialized technology and thus needs sophisticated precision manufacturing process. pmma is one of the most used optical polymer for manufacturing of optical lenses, the shaping of which into the required precision and accuracy is a challenging task. the focus of the present paper is to understand the effect of machining parameters on the surface cha...

This paper presents an application of a nonlinear magnetic levitation system to the problem of efficient active control of mass-spring-damper mechanical systems. An output feedback control scheme is proposed for reference position trajectory tracking tasks on the flexible mechanical system. The electromagnetically actuated system is shown to be a differentially flat nonlinear system. An extende...

in this paper, a new robust controller based on geometric homogeneity and adaptive integral sliding mode is proposed for a class of second order systems. the upper bound of the system disturbances is not required. fully unknown parameters have been considered in the described model and its finite–time convergence to zero equilibrium point is proved. moreover, the controller is developed in the ...

This paper presents a new intelligent method to control rehabilitation robots by mainly considering reactions of patient instead of doing a repetitive preprogrammed movement. It generates a general reference trajectory based on different reactions of patient during therapy. Three main reactions has been identified and included in reference trajectory: small variations, force shocks in a single ...

In this article, a speed control of DC motor is designed and illustrated using fuzzy logic-based programmable logic controller (PLC). The DC motor is an attractive part of electrical equipment in many industrial applications requiring variable speed and load specifications due to its ease of controllability. The designed system is consisted of three main parts including programmable logic contr...