The phrase "an upper boundary" is correct and usable in written English.
It can be used in contexts where you are discussing limits, thresholds, or maximum values in various fields such as mathematics, science, or economics.
Example: "The study established an upper boundary for the temperature at which the reaction could occur safely."
Alternatives: "a maximum limit" or "a top threshold".
The 2007 I.P.C.C. report shied away from giving an upper boundary for sea level rise, for example.
"This is not a target," Dr. Richard Pazdur, the director of the agency's cancer drug office, said about the hemoglobin level of 12. "This is an upper boundary for safety concerns".
One set has an upper boundary of 60 km, with 1 km vertical resolution.
A lower and an upper boundary represent the range of each interval.
In each of these cases, the line between treatment and enhancement is drawn to mark an upper boundary of professional and social obligations.
Relevant standards recommend the determination of the linear elastic modulus via linear regression from stress vs. strain curves, while no information for an upper boundary exists.
A vector (boldsymbol {y} in mathbb {R}_^{K}) is an upper-boundary point of set ({mathcal {S}}) if (alpha boldsymbol {y} in {mathcal {S}}), for any scalar α<1, and (alpha boldsymbol {y} notin {mathcal {S}}), ∀α>1.
In the first iteration (c = 0), these values were given by (6) (brackets denote a set of elements) and represented the lower boundary (lb a ), the upper boundary (ub a ), and their arithmetic average.
However, the OLS model does not restrict the predicted utility to have an upper limit of 1 (which is a definitional upper boundary).
Now, consider a waveguide that differs from an unperturbed waveguide by having a different upper boundary.
In actual fact, mathematics developed by Mark Freeman and colleagues show otherwise, and the decreased lower boundary (from 2°C to 1.5°C) combined with an unchanged upper boundary (4.5°C) has actually increased the expected risk.
