Alarm rate processes

Statistical research in the last decade has cast serious doubt on the wisdom of adding the MR chart to the x chart in n = 1 situations. The price paid for the addition in terms of false alarm rate is not really repaid with an important increase in the ability to detect process change. For a more complete discussion of this issue see Section 4.4 of Vardeman and Jobe.14... 

The signal processor provides the digital processing for pulse compression, Doppler filtering, clutter map, constant false alarm rate (CFAR), and detection thresholding. In a multifunction array radar (MFAR), the... 

Few processes are as unforgiving of errors or lack of attention as an alky unit. Mistakes that one might gel away with on another unit precipitate terrible corrosion rates on alky units. Operating errors that permit H2SO4 to escape from the reactor system can produce weak acid downstream of the reactor. Low-strength acid destroys carbon steel at an alarming rate. 

Advances in analytical chanistry, nucrotechnologies, and computer software have made more techniques available for CWA and TIC detection. Detectors have become smaller, more sensitive, more reliable, and with more functions. Modem computer technologies have permitted more sophisticated data processing to enable fine-tuning of detection algorithms. Further nfiniaturization of detectors that are more sensitive, with lower false-alarm rates, and high tolerance to varied environment conditions snmmarizes the current focus of development. 

Table 10.2 Alarm Rates Per Plant Operator in the Process Industries ...

ML estimation of the (s, v) parameters. The GLRT in Eq. 7 allows also demonstrating the effectiveness of an imaging approach, as in SAR tomography, with respect to the classical interferometric processing. The PSI technique, in fact, exploits a similar test but for the use of only the phase information of each element of the vector g (Ferretti et al. 2000, 2001) the exploitation of the whole complex, amplitude plus phase, data as in Eq. 7 provides a significant increase, with respect to PSI, of the detection probability for a fixed false alarm rate. 

To simulate the next summer s condition the plant was run at the desired production rate and two cooling tower fans were turned off. It turned out that the cold water temperature rose to slightly above that predicted for the next summer. A thorough inspection of critical temperatures and the plant s operation indicated that the plant would barely make it the next summer. Process side temperatures were at about the maximum desired, with an occasional high oil temperature alarm on the large machines. 

Increased operator awareness can be prompted by use of rate of process variable change, at absolute process variable milestones. For example, devices can indicate or be set to alarm if the rate of temperature rise is 5°C/minute for the 10 minutes preceding a process temperature of 100°C. 

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