Standing people are exposed to whole-body vibration in many environments. This paper investigates the effects of horizontal whole-body vibration and standing posture on task performance. Sixteen participants were exposed to random vibration (up to 4 Hz) whilst performing a timed pegboard task in two standing postures. Objective and subjective indicators of performance were used. Time taken to c...

The wavefront of an injection-seeded soft x-ray laser beam generated by amplification of high-harmonic pulses in a λ=18.9 nm molybdenum plasma amplifier was measured by a Hartmann wavefront sensor with an accuracy of λ/32 root mean square (rms). A significant improvement in wavefront aberrations of 0.51±0.03λ rms to 0.23±0.01λ rms was observed as a function of plasma column length. The variatio...

Dust storms are devastating natural disasters that cost billions of dollars and many human lives every year. Using the Non-Hydrostatic Mesoscale Dust Model (NMM-dust), this research studies how different spatiotemporal resolutions of two input parameters (soil moisture and greenness vegetation fraction) impact the sensitivity and accuracy of a dust model. Experiments are conducted by simulating...

Electromagnetic tracking devices are widely used in biomechanics. In this article a method is evaluated to construct models of articular surfaces using an electromagnetic tracking device. First, the accuracy of the space tracker was examined and optimised. Then, from several joint surfaces random points were measured and eighth degree polynomials were fitted to these measurements. To check if t...

In this paper I analyze how debt structure and the strategic interaction between shareholders and creditors in the event of default a¤ect expected stock returns. By endogenizing shareholders’decision to default, the model generates new predictions linking …rm characteristics to expected stock returns through an intuitive economic mechanism. In particular, the model predicts that expected stock ...

The scaling of root mean square (RMS) wave aberration in an isometrically growing eye is investigated, along with changes due to measurements made at different relative pupil sizes. It is found that, relative to an initial state, if an eye expands in all directions by the factor k, and the wave aberration is then measured at a relative pupil size which has changed over the pupil size used for t...

We present a model of competitive interaction among n symmetric …rms producing a homongeous good that includes both Bertrand and Cournot competition as special cases. In our model the intensity of competition is captured by a single parameter –the perceived slope of competitors’supply functions. We show that total welfare increases monotonically with the intensity of competition and the number ...

We setup a model of competitive interaction among symmetric …rms producing a homogeneous good that includes both Bertrand and Cournot competition as special cases. In our model the intensity of competition is captured by a single parameter –the perceived slope of competitors’supply functions. We show when the number of …rms is …xed, total welfare increases monotonically with the degree of compe...

We propose a generalization of the parallelogram identity in any dimension N ≥ 2, establishing the ratio of the quadratic mean of the diagonals to the quadratic mean of the faces of a parallelotope.

Current mitigation levels for noise transients impinging on marine mammals are specified by rms pressures. The rms measure critically relies upon choosing the size of averaging window for the squared pressures. Derivation of this window is not standardized, which can lead to 2-12 dB differences in rms sound pressure for the same wave forms. rms pressure does not represent the energy of the nois...