Categorical factor

A case of application of fractional replica 27-3 of a full factorial experiment on studying adhesion of thermoplastic polymer and fiber has been analyzed earlier in Example 2.33. Tensile strength of adhesion has been measured as the system response. The experiment included seven factors, with the nature of fiber being a qualitative-categorical factor. The regression coefficient values and method of steepest ascent are shown Table 2.188. 

Simplex optimization is used in extreme experiments where besides quantitative-continuous also qualitative-categorical factors are included. 

If some factors are categorical with more than two levels, the corresponding effects are estimated via contrasts. If there are l + 1 levels, estimation of l contrasts comparing each level with (say) level l + 1 are necessary. If F is the categorical factor, and fh-, , Pfi are the corresponding effects, then xFi. . xF, will indicate activity of these effects. Chipman (1996) suggested a prior distribution in which all of xFi,..., tpi are either 0 or 1. This effect grouping allows either all or none of fipi, , Pfi to be active. 

Further statistical analyses can be used to determine the relative influence that any factor or set of factors has on the total variation (global uncertainty). One of these methods is the analysis of variance (ANOVA). This is an important technique for analyzing the effects of categorical factors on a response. However, the assumption of normality of the data has to be checked prior to the use of ANOVA to decompose the variability in the response variable between the different factors. Depending upon the type of analysis, it may be important to determine (a) which factors have a significant effect on the response, and/or (b) how much of the variability in the response variable is attributable to each factor (as described in the statistical software STATGRAPHICS, Vs 5.0). 

Because temperature was considered a categorical factor, the temperature 35°C was used instead of a true middle point of 42.5°C. 

The presentation of statistical results of data from interlaboratory trials can be handled differently in CEN and ISO. CEN presents these data generally in the normative body of the standard, whereas ISO puts them in the informative annex of the standard. Besides the different philosophies in ISO and CEN on the l out of a standard, the organization and evaluation of an interlaboratory trial is obligatory for the standard developers in CEN and ISO, and the quality of the statistical data from the interlaboratory trial is the final categorical factor in the decision to publish the standard method, to postpone or to withdraw the project from the working list. The criteria for interlaboratory trial data to be met are given in ISO 5725, Part 2 (ISO, 2002). 

The most widely used and best known resistance furnaces are iadirect-heat resistance furnaces or electric resistor furnaces. They are categorized by a combination of four factors batch or continuous protective atmosphere or air atmosphere method of heat transfer and operating temperature. The primary method of heat transfer ia an electric furnace is usually a function of the operating temperature range. The three methods of heat transfer are radiation, convection, and conduction. Radiation and convection apply to all of the furnaces described. Conductive heat transfer is limited to special types of furnaces. 

A distinct difference between examiners citations on granted U.S. patents and those on pubHshed patent appHcations is that the latter can indeed represent direct anticipation. Thus they represent a close subject relationship to the document in question. An important factor in the citations on EPO and PCT appHcations is that they are categorized by the examiner with regard to their relevance documents of particular relevance in themselves, documents of particular relevance in combination with some other document(s), and documents defining the general state of the art but of no particular relevance in themselves. Clearly not aH citations have the same value. 

In selecting an appropriate tool, two other factors may also be important. First, it may be beneficial to leverage higher initial cost for a more full featured tool, if future appHcations are likely to need those capabiUties. Second, more than one tool may be necessary to serve the needs of different types of apphcations, ie, the adage "one size does not fit all" holds well in the tool business. Available tools in the market can be categorized into roughly three classes. 

Techniques for controlling the corrosion factor can be categorized into... 

This completes our discussion of the beisis and factors developed by past investigators to describe and conceptulize the structure of solids. You will note that we have not yet fully described the s)unmetry factor of solids. The reason for this is that we use symmetry factors to characterize solid structure without resorting to the theoretical basis of structure determination. That is, we have a standard method for categorizing solid structures. We say that salt, NaCl, is cubic. That is, the Na" ion and the Cl ion are alternately arranged in a close-packed cubic structure. The next section now investigates these structure protocols. 

Transgenic E. coli accumulate comparatively low levels of carotenoids " compared to microbial algae, yeasts, and bacteria. Many efforts ° have focused on increasing accumulation by manipulation of factors affecting metabolic flux and metabolite accnmnlation (listed and discnssed in Sections 5.3.1.1 and 5.3.1.3 A) and have been reviewed." - " In bacterial systems, approaches to control can be categorized as either infrastructural (plasmids, enzymes, strains) or ultrastructural (media and feeding, enviromnent, precursor pools, substrate flux). 

Cancer occurs when the growth and function of cells are out of control in relation to normal tissue. The combination of genetic alterations and environmental toxins is the most frequent contributor to the process of carcinogenesis. In the development of skin cancer, the risk factors are categorized as environmental (solar UV radiation), genetic (family history), immunosuppression, and previous history of melanoma.10... 

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