The phrase "a frequency of at" is not correct in standard written English.
It may be intended to describe a specific frequency level in a context such as science or technology, but it lacks clarity and completeness.
Example: "The device operates at a frequency of at 2.4 GHz, which is optimal for wireless communication."
Alternatives: "a frequency of" or "operating at a frequency of".
The servo must receive a PWM with a frequency of at 20mS and a duty cycle around 20%.
Statistical research suggests that tides of this level are to be expected at a frequency of at least once in 300 years.
Two thirds of both children and adolescents had at least one medical visit during the first trimester of treatment, but only 20% had a frequency of at least one visit per month (i.e. adequate).
1000 Genomes Project, an international collaboration in which researchers aimed to sequence the genomes of a large number of people from different ethnic groups worldwide with the intent of creating a catalog of genetic variations occurring with a frequency of at least 1percentt across all human populations.
While these less-than-zero barrier times are brief, we estimate them to occur with a frequency of at least one per ps such that—over the experimental observation period they help to explain the fast diffusion observed for the nHEX molecule.
At the time of consultation, she was having headaches with a frequency of at least once a week, lasting up to 3 days.
Typical hardware implementation of a 192 Kbytes SDRAM or DDRAM memory, running on a frequency of at least 4 times the frequency of the FIFO banks, is necessary to replace the four logical memories.
PSA was performed in the adult population with a frequency of at least once per week by 53.7% (95/177) of the EPs, and for the paediatric population, this frequency was reached by 19.6% (21/107).
But the most energetic type — X-class flares, like the July 12 , 2012event — are far more rare, occurring at a frequency of at most a few per month.
We chose to identify blocks for which at least 97% of individuals have a haplotype allele that is present at a frequency of at least 2.8%.
Given these limitations, the "sweet spot" for MDAP analysis is for populations of sequences derived from a single consensus and that harbor variants at a frequency of at least 0.3%.
