Bias in particle tracking acceleration measurement

We investigate sources of error in acceleration statistics from Lagrangian Particle Tracking (LPT) data and demonstrate techniques to eliminate or minimise bias errors introduced during processing. Numerical simulations of particle tracking experiments in isotropic turbulence show that the main sources of bias error arise from noise due to position uncertainty and selection biases introduced during numerical differentiation. We outline the use of independent measurements and filtering schemes to eliminate these biases. Moreover, we test the validity of our approach in estimating the statistical moments and probability densities of the Lagrangian acceleration. Finally, we apply these techniques to experimental particle tracking data and demonstrate their validity in practice with comparisons to available data from literature. The general approach, which is not limited to acceleration statistics, can be applied with as few as two cameras and permits a substantial reduction in the spatial resolution and sampling rate required to adequately measure statistics of Lagrangian acceleration

Physical Model of Rainwater Along Roadway Filter Strip

The purpose of this research was to investigate infiltration rates of rainwater into a roadside filter strip. The findings of this study were intended to be used by the Utah Department of Transportation in their design of stormwater retention. A testing apparatus was designed and constructed to simulate rainfall and infiltration on an inclined slope during the 80th percentile 24-hour rainstorm event in Utah. The model was used to test six different surface soil configurations at three slope inclinations. Each test was subjected to a simulated storm event of ½ inch of rain over a 2-hour period. The variation in the top 4 inches of soil resulted in the most significant changes to the amount of infiltration, while the slope had little effect on infiltration for the two topsoil materials. The addition of vegetation resulted in increased amounts of infiltration as did the scarifying beneath the topsoil

Entanglement without nonlocality

We consider the characterization of entanglement from the perspective of a Heisenberg formalism. We derive an original two-party generalized separability criteria, and from this describe a novel physical understanding of entanglement. We find that entanglement may be considered as fundamentally a local effect, and therefore as a separable computational resource from nonlocality. We show how entanglement differs from correlation physically, and explore the implications of this new conception of entanglement for the notion of classicality. We find that this understanding of entanglement extends naturally to multipartite cases.Comment: 9 pages. Expanded introduction and sections on physical entanglement and localit

Simulation of muscle-powered jumping with hardware-in-the-loop ground interaction

We developed a novel reverse haptic interface to augment forward dynamic simulations with real-world contact forces. In contrast with traditional haptics, in which a realworld user drives an interaction with a simulated environment, reverse haptics allows a simulated mechanism to probe the realworld environment through a force-sensing robotic manipulator. This method can implicitly extend computer models of biomechanics and robotic control with complex ground interactions. A 3-DoF manipulator and a biologically inspired musculoskeletal model were developed to test jumping performance on a diverse range of real-world substrates. Jumps were of similar height despite differences in material properties and no active muscle control. Muscle power was lower at the hip, yet total muscle work was higher, against compliant surfaces compared to stiff surfaces. Through reverse haptics, the forces of actuation, inertia and contacts could be measured simultaneously to reveal how intrinsic muscle properties may compensate for substrate dynamics

First-Order and Second-Order Optimality Conditions for Nonsmooth Constrained Problems via Convolution Smoothing

This paper mainly concerns deriving first-order and second-order necessary (and partly sufficient) optimality conditions for a general class of constrained optimization problems via smoothing regularization procedures based on infimal-like convolutions/envelopes. In this way we obtain first-order optimality conditions of both lower subdifferential and upper subdifferential types and then second-order conditions of three kinds involving, respectively, generalized second-order directional derivatives, graphical derivatives of first-order subdifferentials, and secondorder subdifferentials defined via coderivatives of first-order constructions

Quantum marking and quantum erasure for neutral kaons

Entangled K0 anti-K0 pairs are shown to be suitable to discuss extensions and tests of Bohr's complementarity principle through the quantum marking and quantum erasure techniques suggested by M. O. Scully and K. Druehl [Phys. Rev. A 25, 2208 (1982)]. Strangeness oscillations play the role of the traditional interference pattern linked to wave-like behaviour, whereas the distinct propagation in free space of the K_S and K_L components mimics the two possible interferometric paths taken by particle-like objects.Comment: 4 RevTeX page

The aging male: investigation, treatment and monitoring of late-onset hypogonadism in males

Androgen deficiency in the aging male has become a topic of increasing interest and debate throughout the world. The demographics clearly demonstrate the increasing percentage of the population that is in the older age groups. The data also support the concept that testosterone falls progressively with age and that a significant percentage of men over the age of 60 years have serum testosterone levels that are below the lower limits of young adults (age 20-30 years) men. The principal questions raised by these observations are whether older hypogonadal men will benefit from testosterone treatment and what will be the risks associated with such intervention. The past decade has brought evidence of benefit of androgen treatment on multiple target organs of hypogonadal men and recent studies show short-term beneficial effects of testosterone in older men that are similar to those in younger men. Long-term data on the effects of testosterone treatment in the older population are limited and specific risk data on the prostate and cardiovascular systems are needed. Answers to key questions of functional benefits that may retard frailty of the elderly are not yet available. The recommendations described below were prepared for the International Society of Andrology (ISA) and the International Society for the Study of the Aging Male (ISSAM) following a panel discussion with active participation from the audience sponsored by the ISA on the topic at the 4th ISSAM Congress in Prague in February 2004.peer-reviewe