We have tested the proportionality of force and acceleration in Newton's second law, F=ma, in the limit of small forces and accelerations. Our tests reach well below the acceleration scales relevant to understanding several current astrophysical puzzles such as the flatness of galactic rotation curves, the Pioneer anomaly, and the Hubble acceleration. We find good agreement with Newton's second...

This article presents a new performance measure, the actuation eeciency, which describes isotropy in acceleration capability for non-redundant manipulators. It measures the imbalance between the end-eeector accelerations achievable in diierent directions. Prior to this, no measure of this characteristic was adequate for a six degree-of-freedom manipulator, because its end-eeector motions are re...

Fetal cardiac function was measured at 24, 30, and 36 weeks gestation and quantified in terms of heart rate, variability, and episodic accelerations. Children’s representational capacity was evaluated at 27 months in terms of language and play. Thirtyand 36-week-old fetuses that displayed greater heart-rate variability and more episodic accelerations, and fetuses that exhibited a more precipito...

A simple algorithm is presented to calculate the induced accelerations of body segments in human walking for the sagittal plane. The method essentially consists of setting up 2x4 force equations, 4 moment equations, 2x3 joint constraint equations and two constraints related to the foot-ground interaction. Data needed for the equations are, next to masses and moments of inertia, the positions of...

The dynamic environment of a van modified to accommodate a person driving from a wheelchair was measured to determine the effects of position within the van and the type of seat used. The project measured accelerations as a subject sat in three positions within the van and upon two different seats. Three separate van maneuvers at different speeds were used to change the dynamic environment. Van...

A torsion pendulum may be used to measure effective differential accelerations of test masses in the field of sources on distance scales below those accessible in a space experiment such as STEP. Operation of a torsion pendulum at low temperature (2 K) offers many benefits, notably: low thermal noise, high fibre stability, highly effective superconducting magnetic shielding and excellent temper...

This paper explains the effect of a motion platform for driving simulators on postural instability and head vibration exposure. The sensed head level-vehicle (visual cues) level longitudinal and lateral accelerations (ax,sensed=ax_head and ay,sensed=ay_head, ayv=ay_veh and ayv=ay_veh) were saved by using a motion tracking sensor and a simulation software respectively. Then, associated vibration...

In this paper, a method for computing the generalized inertial tensor of manipulator robots is described as based on the Gibbs-Appell equations. The method presents the formulation of the coefficients of the mentioned tensor by means of the Hessian of the Gibbs function. An efficient recursive algorithm is proposed, with a complexity of O(n) order, which is used to produce a program in FORTRAN....

The purpose of this study was to investigate the effects of prolonged high-intensity running on impact accelerations in trained runners. Thirteen male distance runners completed two 20-minute treadmill runs at speeds corresponding to 95% of onset of blood lactate accumulation. Leg and head accelerations were collected for 20 s every fourth minute. Rating of perceived exertion (RPE) scores were ...