Discriminant techniques

D. Coomans, I. Broeckaert, M. Jonckheer and D.L. Massart, Comparison of multivariate discrimination techniques for clinical data—Application to the thyroid functional state. Meth. Inform. Med., 22 (1983) 93-101. 

The most discriminating technique for proving the identity and purity of analyte peak of a chromatogram, especially for analyzing biological samples and natural products, is by using online LC-UV/MS or GC-MS/FTIR methods [15]. Alternatively, one could use a combination of TLC and MS, where direct determination on the TLC plates is made by matrix-assisted laser desorption ionization mass spectrometry (MALDI MS) [16]. 

Shurmer, H.V, Gardner, J.W., Chan, H.T. (1989) The application of discrimination technique to alcohols and tobaccos i ing tin-oxide sensors. Sens. Actuators 18 361-371. 

A kinetic expression that is selected should satisfy certain statistical tests and physicochemical constraints, before it can be indicated as an adequate model. These tests often cannot be applied together, due to lack of information, but should be considered as far as possible in the evaluation and selection of the best rate expression. When still a set of competitive expressions are left some model discrimination techniques may be applied or additional experiments should be conducted, based on a careful, efficient planning. 

Three general categories of nucleic acid discrimination techniques will be reviewed ... 

The second major category of nucleic acid discrimination techniques is hybridization. All hybridization assays are based on the ability of single-stranded nucleic acids to form specific double-stranded hybrids. The process requires (1)... 

Fig 3. Example data consisting of three classes (A, B C) with two descriptors (FI F2) illustrates the Fisher linear discrimination technique. When the data is projected onto the Fisher line, between-class scatter (dashed arrows) is maximized and within-class scatter (solid arrows) is minimized. Gaussian curves for each class, defined by the mean and standard deviation upon projection onto the Fisher line, are also provided. 

A.N. Dills, K.C. Gross, G.P. Perram, Detonation discrimination techniques using a fouiier transform infrared spectrometer system and a near-infrared focal plane array. Proceedings of the SPIE, 5075,208-216 (2003). 

Other model selection and/or discrimination tools include the posterior predictive check (PPG) and cross-validation (27,32,33). The PPG is useful for examination of the ability of the model to predict accurately certain features of the observed data (e.g., maximum concentration). Although PPG is not strictly a model discrimination technique, as it does not compare the predictive performance between models but rather evaluates the predictive performance of a single model, it does have useful characteristics that are discussed in more detail in Section 5.3.3. Gross-validation is considered accurate but is computer intensive and generally considered not to be suitable for small data sets (32). 

Figure 3.3. Fisher s discriminant technique for two populations g = 2), 7Ti( ) and 7T2(o), with equal covariances.

Raven J.A., Macfarlane J.J., Griffiths H. (1987) The application of carbon isotope discrimination techniques. In Plant Life in Aquatic and Amphibious Habitats (ed. Crawford R.M.M.). BES Special Symposium. Oxford Blackwell Scientific. 

Cooling for this length of time will ensure that in chemical reprocessing thorium can undergo total beta decontamination to twice the level of natural Th. The decontamination can be verified with total beta monitoring. For shorter cooling times beta discrimination techniques must be used to ensure that long-lived beta contaminants are not present in the separated thorium. 

It should be noted that statistical techniques only provide guidelines. The judgment and experience of the researcher should not be underestimated, since they are crucial in determining the type and number of models as well as the level at which the discrimination is considered to be sufficient. Moreover, no discrimination technique can identify the best model if it is not included in the discrimination set and if none of the used models are adequate. 

Discriminant analysis techniques (also called classification techniques) are concerned with classifying objects into one of two or more classes. Discriminant techniques are considered to be learning procedures. Given, a set of objects whose class identity is known, a model learns from the variables which have been measured for each of the objects, a procedure which can be used to assign a new object, whose class identity is unknown, into one of the predefined classes. Such a procedure is performed using a well-defined discriminatory rule. 

This multifaceted crisis is articulated to considerable extent through the specter of multiracialism and, for this reason, slates the latter for continued supervision. That is, because multiracialism operates by way of a historic double standard—endorsed when it does not involve blackness in significant ways, abjured whenever it does—it demands supple and discriminating techniques of administration if it is to mitigate the confusions of the day. What I hope to demonstrate in Amalgamation Schemes is that... 

A schematic of the discrimination technique is shown in Fig. 3. As can be seen under standard conditions (or at low applied voltage) both the fully matched hybrid and that with a single-base-pair mismatch remain hybridized making... 

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