Fundamental limits to stereotactic proton therapy

Fundamental Limits to Cellular Sensing

In recent years experiments have demonstrated that living cells can measure low chemical concentrations with high precision, and much progress has been made in understanding what sets the fundamental limit to the precision of chemical sensing. Chemical concentration measurements start with the binding of ligand molecules to receptor proteins, which is an inherently noisy process, especially at ...

Fundamental limits to nonlinear energy harvesting

Ease of miniaturization, and less or no maintenance, among other advantages, have pushed towards replacement of conventional batteries with energy harvesters in particular, vibratory energy harvesters. In the recent years, nonlinearity has been intentionally introduced into the otherwise linear energy harvesters in the hope of increasing the frequency bandwidth and power density. However, funda...

Coronary anatomy to predict physiology: fundamental limits.

Fundamental limits to extinction by metallic nanoparticles.

We show that there are shape-independent upper bounds to the extinction cross section per unit volume of dilute, randomly arranged nanoparticles, given only material permittivity. Underlying the limits are restrictive sum rules that constrain the distribution of quasistatic eigenvalues. Surprisingly, optimally designed spheroids, with only a single quasistatic degree of freedom, reach the upper...

Spectrum Sensing: Fundamental Limits

Cognitive radio systems need to be able to robustly sense spectrum holes if they want to use spectrum opportunistically. However, this problem is more subtle than it first appears. It turns out that real-world uncertainties make it impossible to guarantee both robustness and high-sensitivity to a spectrum sensor. A traditional time-domain perspective on this is relatively straightforward, but t...