Technique-oriented approach

The term Task Analysis (TA) can be applied very broadly to encompass a wide variety of human factors techniques. Nearly all task analysis techniques provide, as a minimum, a description of the observable aspects of operator behavior at various levels of detail, together with some indications of the structure of the task. These will be referred to as action oriented approaches. Other techniques focus on the mental processes that imderlie observable behavior, for example, decision making and problem solving. These will be referred to as cognitive approaches. 

In this chapter we present four case studies to illustrate catalyst characterization from a problem-oriented approach. The intention is to show what can be achieved by using combinations of techniques. The selected studies all have the aim of determining the composition and the structure of a catalyst or a catalytic surface in atomic detail. 

In this chapter, the mathematical formulation of the variable classification problem is stated and some structural properties are discussed in terms of graphical techniques. Different strategies are available for carrying out process-variable classification. Both graph-oriented approaches and matrix-based techniques are briefly analyzed in the context of their usefulness for performing variable categorization. The use of output set assignment procedures for variable classification is described and illustrated. 

More than in the past, a systematic setting of priorities is advocated by the authorities. Development takes place by two approaches (1) an effect-oriented approach and (2) a source-oriented approach. These approaches are based on two issues (1) Which effects are caused by which products-processes (2) Which sources emit-discharge which products In this regard, the scheme from emission to toxicological effect must be traced and concentration techniques must be developed. The close connection between chemical and biological characterization must be strongly stressed in this respect. 

The years from 1960 to 1975 represented a golden era in the radiofrequency and microwave spectroscopy of open shell diatomic molecules. Molecular beam electric resonance was one of the most important experimental approaches, but microwave, far-infrared and magnetic resonance studies of bulk gaseous samples were equally important and our understanding of these open shell species is derived from a combination of different experimental approaches. In this book we have chosen to organise our descriptions according to the experimental techniques employed, but as with any such scheme, we run the risk, which we wish to avoid, of not connecting the results from different types of experiment in a coherent manner. As we shall see, the OH radical is the example par excellence which illustrates the pitfalls of an approach which is technique-oriented, rather than molecule-oriented. 

Inorganic chemistry can be usefully approached from a number of points of view. One can take an element orientation, for example, boron chemistry a phase orientation, for example, solid-state chemistry a function orientation, for example, bioinorganic chemistry a technique orientation. 

The application of FIACCP is mandated for Food and Drink GMPs, and the FDA is exploring its further use for pharmaceutical and healthcare GMPs. It provides a process-orientated approach to identifying and reducing known and potential hazards to an acceptable level. The technique is not specifically intended for computer systems but its principles can be applied with a little modification (see Figure 8.6). 

On one side, application of combinatorial chemistry to sensor discovery could be traced back to very early time, as the receptor discovery has been recognized as an important applicable field for combinatorial chemistry as in medicinal chemistry.15 In this approach, combinatorial techniques are utilized to compensate receptor design, and the fluorophore can be either incorporated into the receptor synthesis or remain independent for displacement assays. Diversity of the receptor part helps for probing the interactions between the receptor and target analyte, thus this approach can greatly facilitate the target-oriented approach in the situations that the receptor is unknown or not easily designed.16 One recent example of mercury sensor development clearly demonstrated the power of this approach (Fig. 17.4).17... 

Successful implementation of a Triad approach is dependent on the availability of a suitable set of instruments chemical, toxicological (bioassays) and ecological. Without doubt, substance-oriented approaches have received a lot of attention in ecotoxicology and the available techniques are relatively mature (Posthuma et al., 2002). The current focus in this field of research is on improvement of bioavailability considerations, the effect of mixtures and the indirect effects of substances. 

With new data for polyelectrolytes obtained with the techniques described above it should become possible to determine carefully the effects of ionic strength and externally controlled surface potential on the rate of adsorption of poly electrolytes. We hope that the effects of molar mass and charge density of the poly electrolyte, as well as the nature of that charge (annealed or quenched) can be established. This should stimulate further theoretical research aimed at constructing an adequate equivalent of the Von Smolu-chowsky-Fuchs theory for the rate of flocculation. At present, it would seem that an analysis of the adsorption process taking all complications into account necessitates a simulation-oriented approach. 

Peiffer, S. (2000) Characterisation of the redox state of aqueous systems - towards a problem-oriented approach. In Redox - Fimdamentals, Processes and Measuring Techniques (Eds. Schiiring, X Schulz, H. D. Fischer, W. R. Bottcher, X Duijnesveld, W. H. M.), Springer Ver-lag, Berlin. 

The need, because of the invisible nature of software and hence the difficulty of tracking of the activities which create software, to make the products of the software process visible and then to control the software process by tracking these now-visible intermediate and deliverable products. The visibility of the products of thought processes is commonly achieved through the use of modeling techniques, such as those developed for stmctured analysis and design and the object-oriented approach. 

A complete requirements document includes not only the functional requirements on the product but also the quality requirements in terms of factors and the levels required for each factor. Software engineers then try to apply techniques and procedures for achieving the stated quality requirements. There are two general approaches to achieving quality requirements product-oriented methods and process-oriented methods. The process-oriented approach concentfates on improving the process followed to ensure the production of quality products. We have already discussed process quality, its assessment and improvement in Section V. Here we review product-oriented techniques for achieving software quality. 

Equation-oriented approaches ate based on sets of equations that are written for the units in a particular flowsheet. Unlike the sequential-modular systems, which often contain the necessary information for a variety of process units, equation-oriented synthesizers require the practitioner to develop the model equations. These are solved through iterative techniques with standard numerical methods. 

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