Software IDENT

Common mode failure Identical software in a dual redundant system will fail when exposed to the same inputs jamming of a mechanical system (either due to failure or due to FOD) overheating of avionic equipment etc. 

The derivation of these requirements is a critical step in the development process because errors and deficiencies at this stage will eventually challenge the validation process if not detected during development. Additionally, defects in the computer system requirements are a potential source of common cause failures in redundant subsystems containing identical software. 

The extent to which software can be made diverse and free from common cause failures is not fully resolved. The use of diverse software in redundant systems (discussed in more detail in Section 9) can reduce the probabihty of common cause failure in comparison with the use of identical software. However, there is no way to... 

The mixture is identical in each example. The peaks are shown separated by 2, 3, 4, 5 and 6 (a) and it is clear that a separation of 6a would appear to be ideal for accurate quantitative results. Such a resolution, however, will often require very high efficiencies which will be accompanied by very long analysis times. Furthermore, a separation of 6o is not necessary for accurate quantitative analysis. Even with manual measurements made directly on the chromatogram from a strip chart recorder, accurate quantitative results can be obtained with a separation of only 4a. That is to say that duplicate measurements of peak area or peak height should not differ by more than 2%. (A separation of 4a means that the distance between the maxima of the two peaks is equal to twice the peak widths). If the chromatographic data is acquired and processed by a computer, then with modem software, a separation of 4a is quite adequate. 

MIMOS II has three temperature sensors one on the electronics board and two on the SH. One temperature sensor in the SH is mounted near the internal reference absorber, and the measured temperature is associated with the reference absorber and the internal volume of the SH. The other sensor is mounted outside the SH at the contact ring assembly. It gives the approximate analysis temperature for the sample on the Martian surface. This temperature is used to route the Mossbauer data to the different temperature intervals (maximum of 13, with the temperature width software selectable) assigned in memory areas. Shown in Fig. 3.21 are the data of the three temperature sensors taken on Mars (rover Opportunity at Meridiani Planum) in January 2004 between 12 10 PM on Sol 10 (10 Martian days after landing) and 11 30 AM on Sol 11. The temperature of the electronics board inside the rover is much higher than the temperatures inside the SH and the contact plate sensor, which are nearly identical and at ambient Martian temperature. 

Testing must be conducted in a typical end-user environment, or in a simulated end-user environment, identical with the environment where the software/computer system will be used. Documentation of testing can be recorded as raw data, such as in a logbook, and should include the parameters tested, and the results of testing. The data should be tabulated as a final report document that includes all details included in the test plan, their execution, the results, and conclusions. The final report document must be signed by appropriate personnel, reviewed as needed, and archived. Upon successful completion of testing, the software/computer system can be released for testing and use in an actual end-user environment. 

Once the resolution has been optimized as a function of gradient rate, one can continue to fine-tune the separation, raising flow rate and temperature. In a study of temperature and flowrate variation on the separation of the tryptic peptides from rabbit cytochrome c, column performance doubled while analysis time was reduced by almost half using this strategy.97 Commercially available software has been developed to aid in optimization. As a final note, in an industrial laboratory optimization is not completed until a separation has been shown to be rugged. It is a common experience to optimize a separation on one column, only to find that separation fails on a second column of identical type. Reproducibility and rigorous quality control in column manufacture remains a goal to be attained. 

Other pattern recognition strategies have been used for bacterial identification and data interpretation from mass spectra. Bright et al. have recently developed a software product called MUSE, capable of rapidly speciating bacteria based on matrix-assisted laser desorption ionization time-of-flight mass spectra.13 MUSE constructs a spectral database of representative microbial samples by using single point vectors to consolidate spectra of similar (not identical) microbial strains. Sample unknowns are then compared to this database and MUSE determines the best matches for identification purposes. In a... 

For determining peak identity, the whole spectral data of the standard and the analyte should be compared, and the value of r or MF or SI can be calculated using the software of the HPLC/densitometer equipment as described above. 

TIC) for each urine sample. For comparison of TICs, Agilent ChemStation software allows one easily to stack (overlay) several chromatograms in the same computer window (Fig. 2.2). This feature helps to identify compounds with common retention times among several samples, but does not contain any mass spectral data for verification of a common identity for these peaks and is most useful for comparison of only a few TICs or a few compounds of interest. In these cases, mass spectral comparisons can be made quickly by visual inspection of the relevant spectra. 

An attribute s value is itself the identity of an object. In software, an attribute may represent stored or computable information. An attribute is part of a model used to help describe its object s behavior and need not be implemented directly by a designer. 

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