The phrase "a focal system" is correct and usable in written English.
It can be used in contexts related to systems theory, optics, or any field where a central or primary system is being discussed.
Example: "In our research, we identified a focal system that significantly influences the overall performance of the network."
Alternatives: "central system" or "primary system".
Making a focal system deal with something it otherwise had not, implies a comparatively close proximity to it.
The publicity-stopover option is characterized by indirectly irritating a focal system via a relevant public that is assumed to have an influence on the original target.
A focal system will only change its usual way of processing, if an irritation is able to indicate a problem of this otherwise smoothly running routine.
Unlike the first irritation strategy, to make use of publicity as a stopover on the way to a focal system, proximity is not necessary.
In "The concept of irritations" two types of promising irritations are elaborated on promising with regard to be taken up by a "focal system".
Taking a closer look on this mechanism reveals that it is a certain kind of "detour" that compensates for the missing link to a focal system.
Lenses like that one are designed with a completely different focal system in mind, and the image comes out the interior end in a size and shape the iPhone wouldn't know what to do with.
Making publicly known that the usual way of a target's information processing causes damages (for itself, for society, for the environment), may work out as a shock that makes the focal system reflect this routine.
Here we describe protocols for the alignment and calibration of a focal uncaging system.
We have developed a focal sweep system where mirrors of different shapes can be used to capture wide field of view EDOF images.
Solutions were applied using a focal perfusion system (DAD-12, ALA Scientific Instruments, Westbury, NY, USA).
