A simple quantum-defect model gives analytic expressions for the complex scattering length and threshold collision rates of ultracold molecules. If the probability of reaction in the short-range part of the collision is high, the model gives universal rate constants for s- and p-wave collisions that are independent of short-range dynamics. This model explains the magnitudes of the recently meas...

We show quantitatively how the collision rate of droplets of visible moisture in turbulent air increases very abruptly as the intensity of the turbulence passes a threshold, due to the formation of fold caustics in their velocity field. The formation of caustics is an activated process, in which a measure of the intensity of the turbulence, termed the Stokes number St, is analogous to temperatu...

Ensuring safe and efficient mobility is a critical issue for smart city operators. Increasing safety not only reduces the likelihood of road injuries and fatalities, but also reduces traffic congestion and disruptions caused by accidents, increasing efficiency. While new vehicles are increasingly equipped with semi-automation, the added costs will initially limit the penetration rate of these s...

conclusions higher age of cyclists and increasing speed of the accident opponent significantly increase the likelihood of sustaining facial fractures. the use of bicycle helmets does not significantly reduce the incidence of mid-facial fractures, while being correlated with an even increased incidence of mandibular fractures. background the effectiveness of bicycle safety helmets in preventing ...

This paper proposes a real-time movement control algorithm for massive unmanned aerial vehicles (UAVs) that provide emergency cellular connections in an urban disaster site. While avoiding the inter-UAV collision under temporal wind dynamics, the proposed algorithm minimizes each UAV’s energy consumption per unit downlink rate. By means of a mean-field game theoretic flocking approach, the velo...

BACKGROUND It has been reported that arthroscopic shoulder stabilization yields higher rates of failure in contact or collision athletes as compared with open shoulder stabilization; however, this is largely based upon studies that do not employ modern, evidence-based surgical indications and techniques for arthroscopic shoulder stabilization. PURPOSE To (1) determine the pooled failure rate ...

the conventional theory of adverse selection is not supported by most of the empirical works. these studies conclude that low-risk individuals demand more insurance services than high-risks. they refer to this situation as advantageous selection theory. this theory states that loss ratio of insureds may be lower than the population loss ratio while the conventional theory of adverse selection c...

A fast collision detection and resolution scheme is one of the key components for interactive simulation of deformable objects. It is particularly challenging to reduce the computational cost in collision detection and to achieve the robust treatment at the same time. Since the shape and topology of a deformable object changes continuously unlike the rigid body, an efficient and effective colli...

Sensor collision (interference) is studied in a large network of low bit-rate sensors that communicate via backscatter, i.e. modulate the reflection of a common carrier transmitted by a central reader. Closed-form analysis is provided, quantifying sensor collision (interference) in high-density, backscatter sensor networks (BSN), as a function of number of tags and aggregate bandwidth. Analysis...