We look at the problem of real-time tumor tracking and motion compensation in radiotherapy techniques from a pure feedback-control point of view and try to understand it using simple mechanical models of the treatment couch and breathing patterns. Since we want to control a robotic couch based on the data collected in real-time, we propose the use of an acceleration sensor to develop a feedback...

Computing displacement from measured acceleration is important for understanding the characteristics of an earthquake. However, to obtain such displacement with a good accuracy is difficult. It is partly because the low-frequency component dominating the behavior of the displacement is often affected by the sensor’s tilt and the measurement error. To avoid these, a high pass filter is usually a...

A quantum gravity-gradiometer consists of two spatially separated ensembles of atoms interrogated by pulses of a common laser beam. The laser pulses cause the probability amplitudes of atomic ground-state hyperfine levels to interfere, producing two, motion-sensitive, phase shifts, which allow the measurement of the average acceleration of each ensemble, and, via simple differencing, of the acc...

Abstract The motion of a toppling iPad is analyzed in detail. Measurements angular velocity and linear acceleration were made for about the edges corners. From analysis velocity, position center mass gyration radii determined. accelerometer was measured using both centrifugal Euler acceleration, with latter measurement providing more accurate data. This experiment could be used first year unive...

The interference method for determining the speed of objects using direct optical heterodyning (PDV-Photonic Doppler Velocimetry) has become widespread due to simplicity setting up fiber-optic system, unambiguousness results, and wide possibilities varying measurement accuracy temporal resolution. can be fractions a percent, but there are number factors that prevent this. For example, change in...

on the circular curve, lateral acceleration affects comfort. on the spiral, both lateral acceleration and jerk affect comfort.  the determination of maximum curving speed on the basis of lateral acceleration only is not critical because the lateral acceleration is proportional to the square of speed whereas jerk is proportional to cubic power of speed. the maximum speed on a curve is thus signi...

With a handful of measurements of limb-darkening coefficients, galactic microlensing has already proven to be a powerful technique for studying atmospheres of distant stars. Survey campaigns such as OGLE-III are capable of providing ∼ 10 suitable target stars per year that undergo microlensing events involving passages over the caustic created by a binary lens, which last from a few hours to a ...