Qualitative reasoning

The advantage of qualitative models over quantitative models is that it is not necessary to develop the quantitative relationships, only to establish the trends and influences. Qualitative 

Other researchers have improved on both knowledge base and sensors, often using different programming tools, but with much the same results. Most of these systems have not been transitioned to commercial application because they were developed by researchers who had no interest in the development of user interfaces and the continued support that is necessary for a commercial software package. As a consequence of the success of these experimental systems, however, the developers of commercial supervisory control packages are moving to incorporate support for expert system logic into their software [24,25], 

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Kuipers, B. Qualitative Reasoning Modeling and Simulation with Incomplete Knowledge, MIT Press, Boston (1994). 

Weld, D. S., and J. de Kleer (ed.). Readings in Qualitative Reasoning About Physical Systems. Morgan Kaufman, San Mateo, CA (1990). 

Quahtative simulation is a specific KBS model of physical processes that are not understood well enough to develop a physics-based numeric model. Corrosion, folding, mechanical wear, equipment failure, and fatigue are not easily modeled, but decisions about them can be based on qualitative reasoning. See Refs. 178 and 292. 

Molecules of the size of the fullerenes require such approaches to help rationalise the results. Even though the number of classical structures can be very large the same qualitative reasoning can be used as with the smaller molecules, typically benzene. The enumeration of classical structures is easily accomplished using computers. It is simply a problem of determining how many ways a set of points (in our case carbon atoms) can be coimected given rules governing their connectivity. 

We now ask how well does the bond fluctuation model with these bond lengths and bond angle potentials reproduce the properties of real polymer melts quantitatively. First of all, it must be admitted that the model yields a qualitatively reasonable picture of the amorphous structure, as exemplified by... 

Figure 19(a) shows the QM simulation of the differential cross-section (DCS) in the HF + D channel, over the same extended energy range as in Fig. 5. The agreement with experiment is seen to be qualitatively reasonable. The forward-backward peaking and direct reaction swathe observed in the experiment also occur in the QM calculation, although the relative magnitudes are not consistent. Thus fully quantitative agreement between QM calculations and experiment in all of the reaction attributes must await further refinements of the PES, and/or a more rigorous treatment of the open-shell character of the F(2P) atom.90...

Reject any mechanisms that are grossly inadequate by qualitative reasoning. Do not attempt to do a complicated quantitative or statistical analysis. 

The objectives in the following talk are to discuss qualitatively the time behaviour of exhalation in closed cans and then compare these qualitative reasonings with the exact results of the time-dependent diffusion theory. The theoretical results are, to a large extent, presented in diagram form only. Readers interested in the exact equations behind these diagrams are referred to the paper by Lamm (Lamm et al., 1983). 

There is a need for improved modeling tools to accommodate heuristic and qualitative reasoning. 

If, in fact, the environment atoms are allowed to move, the rigorous estimation of A/.>7- is unclear. Kollman and co-workers have assumed that the effect of the ghost forces cancel for comparisons of similar ligands, and used a transition rule following Equation 18 instead of Equation 35 in their CMC/MD simulations.7,53 This approximation was demonstrated for some systems to be at least qualitatively reasonable.6,7... 

The qualitative reason is quite simple. Consider an adsorbent molecule the states of which are labeled by index j. The probability of finding an empty molecule in state j is Pj 0). Suppose the molecule has m binding sites, and the binding constant to the first site is k (j) when the molecule is in state j. If m = 1, then, as in Section 2.5, we shall obtain a Langmuir isotherm with binding constant A , which is simply an average the sum being over all the states of the molecule. If there... 

A valuable guide is available to assist you in estimating how chemical equilibrium will shift in response to changes in the conditions of the reaction, such as a modification of temperature or pressure. The French chemist Henri Le Chatelier realized in 1884 that if a chemical system at equilibrium is disturbed, the system would adjust itself to minimize the effect of the disturbance. This qualitative reasoning tool is cited as Le Chatelier s principle. 

It is evident that the same qualitative reasoning can be applied to any reaction which can be written in the form of a conventional chemical equation The reactants on both sides correspond to regions of configuration space which are separated by an energy barrier. The differences between various reactions lie in the atomic coordinates involved and the intricacy of the potential surface. 

The key to optimum design for multiple reactions is proper contacting and proper flow pattern of fluids within the reactor. These requirements are determined by the stoichiometry and observed kinetics. Usually qualitative reasoning alone can already determine the correct contacting scheme. This is discussed further in Chapter 10. However, to determine the actual equipment size requires quantitative considerations. 

This is in spite of the qualitatively reasonable energies the basis yields. Such an outcome is a familiar one, however - the energy is the result of a variational calculation and is expected to be produced to higher order than quantities like the electric moment. In addition, the minimal basis does better in the region of the minimum and asymptotically than elsewhere. Thus, Dg may not suffer too greatly. 

In this section we consider some molecules that can be viewed as consisting of methylene radicals in some combination. Earlier publications[39,66] have covered some of the aspects of the subjects covered here. These earlier studies used an ST03G minimal basis, and provide information to make comparisons of results with the 6-3IG results that are presented here. We will describe the minimal basis results more completely in a later section. Here, however, we make one comment concerning the way one must handle these different bases. When using minimal bases with targeted correlation qualitatively reasonable results are obtained, but this is, in part, due to the less satisfactory representation of the fragments. When we use... 

Whereas fuzzy logic offers an improvement over qualitative reasoning in some aspects, the relationships it uses still must be derived from data. There fortunately, exists a means of automating the development of these relationships, even in the absence of a detailed analytical model. 

Bobrow, D. (Ed.). Qualitative Reasoning About Physical Systems, MIT Press, Cambridge, MA, 1984... 

In spite of the above qualitative reasons for preferring a low relief temperature, the simple sizing equation (see 7.3, below) for gassy systems does not enable any benefit (in terms of a reduced Relief size) to be obtained from either a low relief temperature or a low relief pressure. Alternative relief sizing methods (see 7.4) do allow such factors to be taken 1 into account and for a smaller relief size to be obtained. 

The separation between qualitative and quantitative knowledge is not always as great as has been suggested. Give an example where qualitative reasoning and quantitative reasoning have interacted in classroom studies or work experience. 

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