The phrase "are derived from existing" is correct and usable in written English.
It can be used when discussing sources or origins of something, indicating that it comes from pre-existing elements or materials.
Example: "The theories presented in this paper are derived from existing research in the field of psychology."
Alternatives: "are based on existing" or "come from existing".
Important cost-benefit synergies can be achieved if indicators are derived from existing data.
The majority of the techniques are derived from existing uni-processor energy-aware systems that take on new dimensions in the MPSoC space.
The analytical methods are derived from existing ontological bases, and seek to promote consistency and comparability from one analysis to the next.
To a lesser extent, the review addresses contaminants that are derived from existing low- to middle-level radionuclide waste that may need to be stored securely for many years.
Most frequency-domain algorithms, as they are well known from the single-channel case, are derived from existing time-domain algorithms and are based on different heuristic strategies, e.g, for stepsize normalization.
Most of the measurements are derived from existing instruments and are confined to few of the following dimensions: affect, activity, enjoyment, self-esteem, and social interactions [ 7].
It is derived from existing space accelerometers.
Field patterns, crop allocation and agricultural practices were derived from existing datasets and complementary field surveys.
The SCI is derived from existing technology integration learning environment instruments, including TROFLEI, TICI and CCEI (ergonomic).
Consequently, a fundamental argument against using embryonic stem cells and therapeutic cloning cannot be derived from existing constitutional law and additional court decisions.
While fuel cells reinvent the look and function of automotive power plants, hydrogen internal combustion engines are less complicated and costly because they can be derived from existing engines.
