The phrase "a system of hard" is not correct and lacks clarity in written English.
It may be intended to describe a system characterized by hardness, but it requires additional context to be meaningful.
Example: "The engineers developed a system of hard materials to withstand extreme temperatures."
Alternatives: "a framework of rigid" or "a structure of solid".
A system of hard drives catalogs cable news.
In this paper, we present a massively parallel method that obeys detailed balance and implement it for a system of hard disks on the GPU.
Maxwell had studied specific mechanical models for a gas (as a system of hard spheres (1860) or of point particles exerting a mutual force on each other inversely proportional to the fifth power of their distance), and characterized the state of such a gas by means of a probability distribution f over the various values of the molecular velocities $\vec{v} $
That would include "warning labels on the packets, health-seeking information, consumer information, and... a system of hard-to-get but easy-to-lose licenses for production, wholesale, and retail".
Progress in mathematics may eventually resolve the issue, and there is at least one recent result that justifies optimism: Simanyi (2004) shows that a system of n hard balls on a torus of dimension 3 or greater is ergodic, for an arbitrary natural number n.
Contrary to what is sometimes asserted, not even a system of n elastic hard balls moving in a cubic box with hard reflecting walls has been proven to be ergodic for arbitrary n; it has been proven to be ergodic only for n ≤ 4. To this charge one could reply that what looks like defeat to some, appears to be a challange to others.
Localized deformation and cracking in a system of thermally sprayed hard metal coating overlaid on a low alloy steel is studied by means of bend testing.
General relativity is based on a system of equations notoriously hard to solve, but shortly after Einstein set out his new theory he produced a particular solution to his equations describing an unusual form of waves that travel across space at the speed of light.
Wojciechowski, K. Constant thermodynamic tension Monte Carlo studies of elastic properties of a two-dimensional system of hard cyclic hexamers.
To simplify matters our explanations refer to a basic multi-particle system of hard spheres, but can be extended easily to a wide variety of possible models.
What we developed was a system of a really, really hard tempo, playing four lines to do it".
