This is a perfectly correct and usable phrase in written English.
It is used to describe the central or most important element of something. For example, "The core means by which we measure our success is our customer satisfaction survey results."
Hard core means passionate.
Goats and especially cattle are one of the core means of surviving here.
"The idea has reached trainers and through them the public that the core means only the abs.
Samurai shopping at its core means no purchases based on a show of hands: Samurais know what compliments them and what doesn't.
"The focus of policymakers on advertising as the core means of funding public service content beyond the BBC has remained unshakeable despite the evidence of the sustained challenges facing the terrestrial broadcasters".
The developed system can measure yarn average diameter, diameter variation over length, variation of yarn mass, yarn faults, number of hairs at specific distances from yarn core, mean absolute deviation and coefficient of variation in a single run.
So what does the ascendancy of L.A.'s central core mean?
"Poetry Fix" is giving viewers a chance to be smart about poets and to be set aflame with the realization that poets, writing broken lines with meter and metaphor at their core, mean to do more than decorate the truth--they mean to convey it with an insistence of understanding that can't be denied.
These values are also close to those of the atoms located in the hydrophobic core (mean 15Å), therefore the side chain of Arg85 can be considered rigid.
Liquid fraction of cores means the flow rate ratio at the outlet of the high permeability and low permeability cores.
