Algorithm compensation

Search systems are powerful tools, but as for most algorithms described in this chapter, care must be taken when they are used. The unknown and the hbrary spectra must both obey Beer s law. Care must be taken that the wavenumber calibration of an instrument is correct as wavenumber shifts may occur between the unknown and the hbrary spectra. The algorithms compensate for spectral shifts to some degree, but they cannot compensate for large shifts. In addition, the spec-troscopist must remember two important caveats (1) a hbrary search cannot identify an unknown unless the unknown is in the hbrary and (2) a high value of the hit quality index is not necessarily an indication of a correct match. The judicious spec-troscopist will visually compare the spectra of the unknown to the best matches to determine if they are indeed identical. In fact, the best test is to perform a spectral subtraction between the unknown and the hbrary match to see if there is a nonzero residual. If the two spectra are not identical, a nonzero subtraction will result. Finally, it should be recognized that spectral similarity does not indicate structural similarity. Certainly, some of the functional groups in structurally similar molecules will be the same, but the overall structure of an unknown and the best matches that result from a search may be quite different. 

An extension of these metliods to 3D is the Feldkamp algorithm [7], a standard in 3D-tomographic reeonstruction today. In this case off-midplane voxels are taken into eonsideration through weighted filtered 3D-baekprojection. llie weighting compensates for the longer way an oblique ray has to travel. 

Measure Wall Thickness This window is used for the dialog to calibrate the algorithm aceording formula (3) and for point wise measurements after calibration. The row Ideal indicates the nominal wall thickness used, IQI indicates the wall thickness values used for calibration and the detected optical density. Local can be used for noise reduction and compensation of geometric effects. 

Licht et al. [17] developed a method of numerical analysis to describe the above-quoted equilibria of the 11 participating species (including alkali metal cations) in aqueous polysulfide solution, upon simple input to the algorithm of the temperature and initial concentration of sulfur, alkali metal hydroxide, and alkali metal hydrosulfide in solution. The equilibria constants were evaluated by compensation of the polysulfide absorption spectrum for the effects of H8 absorption and by computer analysis of the resultant spectra. Results from these calculations were used to demonstrate that the electrolyte is unstable, and that gradual degradation of polysulfide-based PECs (in the long term) can be attributed to this factor (Chap. 5). 

These modern computer controlled ignition systems use multiple sensors to determine optimum firing. This may include double pick-up sensors on the flywheel to determine rpms under acceleration and deceleration, intake and atmospheric pressure compensation, oxygen sensor levels to maximize combustion, temperature sensors and exhaust emission sensors. All this data is constantly fed into the on-board computer and processed using complex algorithms to determine optimum firing and fuel consumption levels. 

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