The phrase "ad hoc classifications" is correct and usable in written English.
It can be used when referring to classifications or categories that are created for a specific purpose or situation, rather than being based on a general or established system.
Example: "The researchers developed ad hoc classifications to analyze the unique data sets collected during the study."
Alternatives: "temporary classifications" or "specific classifications".
In such cases, ad hoc classification models based upon a few visibly different peaks (e.g. near 920 and 1100 cm−1, marked with '*') perform poorly at the single-spectrum level, where noise is higher.
We used an ad hoc classification based on DSM IV that yielded differences in LOS when analyzed univariately and when it was adjusted for other variables as well.
A more plausible hypothesis is that such ad-hoc classifications are circumstantially created using mechanisms that are closer to a distance calculation between high dimensional, distributed, vector representation of concepts.
The ad-hoc classification into "identifying data" and "other types of data" is insufficient.
In one, a descriptive analysis of marriage and childbearing histories is presented; in another, an ad-hoc classification of life courses is presented; in a third, a statistical method (i.c., a monothetic divisive algorithm) is applied.
There was only one case, which could either be ophthalmoplegic or hemiplegic (according to the 1962 ad hoc committee classification of headache disorders, which lumped hemiplegic and ophthalmoplegic migraine together).
This follows the nomenclature introduced in [ 17] and applies an ad hoc criterion of classification.
The confusion and resulting bureaucratic setback arose thanks to the UC system's recent, massive, multiyear project to bring all its postdocs, who formerly worked under a wide variety of rules, job titles, and ad hoc arrangements, into a single administrative classification--with a common benefits package--governed by Section 390 of the university system's Academic Personnel Manual (APM 390).
It also matters because, as the ProPublica piece notes, the standards for classification are vague and ad hoc.
Recently, researchers have recognized the importance of deriving ad hoc domain-specific features for specific audio classification problems.
A separate ad hoc analysis of FACT-F by FAB classification did not reveal meaningful information because of the unequal numbers of patients in each class.
