Matching quality

File name Retention Time Library ID Match Quality... 

When this spectrum was compared to a reference spectrum, a matching quality of 98% allows an appreciable identification in the real sample in multiresidue applications. 

Let us consider color match quality. The color formulator should ask the customer if the closeness of a match to the color target is the highest priority. Since there are hundreds of colorants available for the color formulator to select from, more than one possible combination of colorants may produce an acceptable match. Is the best, nonmetameric match of most importance to the customer and application If a perfect, nonmetameric match is not possible, which is often the case when trying to match plastic colorant systems to color targets in paint, ink, ceramic systems, or plastic media, will the customer accept some metamerism Also what light source will be the customer s preference when judging a slightly metameric match ... 

TABLE 7-1 Example of Printout of Bacterial Identification Thi ough PMF Using MALDI-TORA Generated Mass List Is Compared With Theoretical Tryptic Masses for Proteins In a Database, Match Quality Is Used for Pathogen Identification. 

The developed systems for schema and ontology matching typically support several match algorithms (or matchers) and combine their results for improved match quality. There exists a large spectrum of possible matchers and different implementations... 

The standard approach for pairwise schema matching is to compare every element of the first schema with every element with the second schema to determine matching schema elements, i.e., evaluation of the cross join. Such an approach has at least a quadratic complexity with respect to schema size and does not scale well. There are not only efficiency problems for large schemas but the large search space makes it also very difficult to correctly identify matching element pairs. Hence, it is important for large match tasks to reduce the search space in order to improve at least efficiency and, potentially, match quality. 

Fig. 10.1 A tuned matcher mainly improves matching quality...

Table 10.1 Impact of the number of training data on the matching quality with Apfel s decision tree ...

Fig. 10.3 Impact on the matching quality when promoting recall with YAM...

In this section, we have mainly presented user inputs, i.e., optional preferences and parameters applied to data. To sum up, the quality can be improved by using external resources and expert feedback. Several tools are based on machine learning techniques either as a similarity measure (mostly at the instance level) or as a means of combining the results of similarity measures. In both cases, training data is a crucial issue. Finally, many tools propose preferences or options which add more flexibility or may improve the matching quality. The next section focuses on the parameters at the similarity measure level. 

Match quality level with criticality of service... 

The major component of cranberry seed extracted via either pure CO2 or hexane was linoleic acid (omega-6 fatty acid) as determined by total ion chromatogram and selected ion chromatogram with an internal standard. The broad intense linoleic acid chromatographic peak is believed to be a mixture of positional isomers of the CI8 2 fatty acid such as 9,12-octadienoic acid 8,11-octadienoic acid, 5,7-octadienoic acid, and 9,11-octadienoic acid. Two other Cl8 fatty acids were identified oleic acid and linolenic acid. The extracted ion of mass 297 0.5 seen at retention time 44.30 min corresponded to oleic acid (molecular weight = 296.5, match quality = 91%). The extracted ion of mass 293 +,0.5 seen at retention time 44.32 min corresponded to linolenic acid (molecular weight = 292.46, match quality = 99%). 

In the past decade, many companies were lured into the plastic area by the promise of large profits from a small investment. They entered their chosen segment of the market by matching or nearly matching large volume products of established producers. If they could not match quality or service, they were willing to compensate for their deficiency by reducing prices. Some of these companies have prospered. 

Table 1. Compounds identified (>74% match quality) in LHl urine (3/11/03) of Alice by ECC/CT and GC-MS (physiological pH = 8,37 C, NaCl added).

The supplier must buy only from those people who they know will be able to provide in accordance with the supplier requirements and the vendors must match quality and delivery needs. 

The average values of five replicate spectra from independent chromatographic runs are listed, except where low match quality did not provide identification. 

The list of AMDIS identified compounds of the headspace analysis and liquid extractions are given in the following Tables 4.30 -4.32 with compound name, CAS numbers as well as the peak quality parameters retention time and the measured peak width and tailing information. The result of the mass spectrum library comparison is given in the most right columns. The Reverse fit column informs about the match quality in % of the spectrum pattern of the proposed library entry with the unknown spectrum (reverse search). 

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