Classification methods categorization

There are also differences in categorical classification methods. Prototypic classification is a method that suggests the indicators for inclusion and exclusion from a category are fallible rather than perfect. In a psychiatric classification system, the patient s assignment to a category is based on the similarity of that patient to the most typical patient for that disor-... 

When the evident or ignored variables defining the categorization are continuous, the problem is instead a correlation problem. The classification methods are qualitative, while the correlation ones are quantitative. 

The components, which are added to enhance or modify catalytic functions, are called promoters or additives. In general, the active components are dispersed on the surface of materials, called supports or carriers, to increase the surface area and/or stability of the active components. Typical supports include metal oxides, such as alumina, silica, and titania, and zeolites that possess micropores. The categorization of catalyst materials into three components active, additive, and support - is a convenient classification method. 

An additional data source that Mobius allows users to create is the calculated field. A calculated field is simply a computed expression of arbitrary complexity involving one or more existing database fields for example, the ratio of two IC50 values for two different assays. The user can optionally apply a classification method to the output value of a calculated field to categorize the result. For example, the base calculated field could simply consist of a chemical structure column and the classification could assign a chemical template name to the structure based on a set of user-defined substructure query classification rules. As with annotation tables, calculated fields can be associated with project data and assigned security attributes. Both annotation tables and calculated fields are full members of the overall integrated database and can be searched, sorted, and combined with any other data in the database. 

One of the most popular pattern recognition methods in chemistry is SIMCA, an acronym for soft/simple independent modeling of class analogy. The central idea is to represent each class of objects by a separate principal component model. Because a probability can be estimated for belonging to a certain class and because outliers can be detected the method is called soft. Classification methods such as discriminant analysis are called hard if they give a categorical answer about the class membership. 

Pilot plants can be categorized by a number of different methods. Size is the most common classification as it is the most uniformly proportional to constmction and operating costs some typical characteristics are shown in Table 2. These characteristics are generalizations and may not be appHcable in... 

In chapter 1, we discussed differences in classification strategies. The strengths and implications of the use of categorical versus dimensional methods of classification were reviewed. In the United States, there has historically been a strong bias toward dimensional typologies (Meehl, 1992). As would be expected, the DSM has been criticized by proponents of a dimensional approach (Carson, 1991). If certain forms of psychopathology are best viewed as dimensional phenomena, the current diagnostic dichotomies are arbitrary. 

To fully characterize and categorize the solute selectivities of GC stationary phases, Rohrschneider and McRe5molds pioneered one of the earliest characterization methods [5,6]. The Rohrschneider-McReynolds system is the oldest and widely accepted stationary phase classification systems that is based on the retention of five probe molecules namely, benzene, bufanol, 2-penfanone, nifropropane, and pyridine. Each probe molecule is used to represenf a disfincf or a combination of interactions with the stationary phase. Benzene measures dispersive interactions with weak proton acceptor properties butanol measures dipolar interactions with both proton donor and proton acceptor capabilities 2-pentanone measures dipolar interactions with proton acceptor but not proton donor capabilities nitropropane measures weak dipolar interactions and pyridine measures weak dipolar interactions with strong proton acceptor but not proton donor capabilities. 

The possibility of categorizing glycoproteins according to the nature of the carbohydrate-peptide bond contained has been suggested.38 To some extent, this method is possible, but, as was pointed out, it does not result in a rigid classification, for examples are known in which more than one type of carbohydrate moiety is attached to a given polypeptide chain. 

Given the number of methods of calculating log Poct, the ability to assign each to one of several categories would be helpful. Almost all the contributors to this field have attempted some sort of categorization, but so much overlap exists in the proposed classifications that much confusion remains. 

Many heteronines are synthesized using another ring-expansion reactions, while contractions of the larger rings into nine-membered heterocyclic systems are less frequent. General methods for ring expansions were categorized in CHEC-II(1996), and this classification is followed in the current section. 

---