Random decrement

Asmussen, J. C., Ibrahim, S. R. and Brincker, R. Application of vector triggering random decrement. In Proceedings of 15th Intematiortal Modal Analysis Conference (Orlando, FL, 1997), Vol. 2, pp. 1165-1171. 

Vandiver, J. K., Dunwoody, A. B., Campbell, R. B. and Cook, M. F. A mathematical basis for the random decrement vibration signature analysis technique. Journal cf Mechanical Design 104(2) (1982), 307-313. 

Another test requiring focused attention is digit or letter cancellation, in which subjects mark through a certain numeral in a page of random numbers or a certain letter in a page of text or random letters. The typical duration of cancellation tests is 1 to 2 min. Two studies reported that diazepam (10 or 15 mg)157 and lorazepam (1 and 2 mg)124 impaired digit cancellation performance. Interestingly, Brown et al.157 found that impaired focused attention was not correlated with the ability to encode associative information. These studies confirm numerous previous studies that reported benzodiazepine-induced decrements in cancellation tests.7... 

Sensor-display compatibility may not, however, be overly critical to performance. For example, Neilson and Neilson [1980] found no decrement in performance on random tracking of overall error scores, such as mean absolute error, between a light pen and a 1-D joystick nevertheless, the latter did result in a decrease in gain, an increase in phase lag, and an increase in the non-coherent response component. Conversely, normal subjects find incompatible 2-D tracking very difficult to perform, taking up to 4 h of practice to reach a level of performance equal to that seen on prepractice 2-D compatible tracking [Neilson et al, 1998]. 

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