Language, imprecision

To bridge the gap between the descriptive but imprecise language that we use in conversation and the more quantitative tools that are used in science, a computational method is required that can analyze and make deductions from imprecise statements and uncertain or fuzzy data. Fuzzy logic is this tool. 

An inhibitor is a substance that retards a reaction. An inhibitor is also present in "catalytic" or sub-stoichiometric amounts. In a radical chain reaction an inhibitor may be a radical scavenger that interrupts the chain. In a metal catalysed reaction an inhibitor could be a substance that adsorbs onto the metal making it less active or blocking the site for substrate co-ordination. We also talk about a poison, a substance that stops the catalytic reaction. A poison may kill the catalyst. The catalyst dies, we say, after which it has to be regenerated wherever possible. We will often see the word co-catalyst, a substance that forms part of the catalyst itself or plays another role somewhere in the catalytic cycle. We inherited a florid language from our predecessors to whom catalysis was black magic. Naturally, these words are rather imprecise for a description of catalysis at the molecular level. 

What is a delta (A) but an excuse for teachers to be lazy I call this the curse of delta. Too often delta is allowed to take on a life of its own without the student understanding that it symbolizes a change in some property between two different thermodynamic states. In fact as I write this piece 1 noted a colleague who referred to AG as a state function. The state function is G all right but delta just describes a process. How can a struggling student understand this crucial difference when as instructors we either, do not understand the difference ourselves, or continue to be imprecise in our use of language Instead of delta... 

The Maestro s prophecies are always couched in imprecise language, but this is not trickery—he is often as mystified as anyone, for he retains no memory of writing them or what he has foreseen. We have spent days trying to interpret some of his gibberish. By comparison, this quatrain seemed positively lucid, and he obviously expected me to reach the same conclusion he had, at least about the final line. 

Not the least important of Boyle s practices concerning experiment was his habit of reporting experimental failures and disappointments. Failed experiments could suggest new lines of research or improvements in technique. Also valuable was his insistence on avoiding imprecise and arbitrary language in re-... 

In fuzzy logic, the use of fuzzy if-then rules is governed by the calculus of fuzzy rules, CFR. A major part of CFR is the Fuzzy Dependency and Command Language, or FDCL for short. Basically, FDCL is a fuzzy programming language that provides a powerful tool for the representation and manipulation of imprecise or ill-defined dependencies. Two issues play pivotal roles in FDCL. The first is interpolation, and the second relates to the induction of rules from observations. 

Imprecise language may satisfy definiteness requirement (for one of ordinary skill). So dimensioned" or so spaced" can be definite if it is as accurate as the subject would permit about" is clear and flexible, but rendered indefinite if specification or prior art does not provide indication about the dimensions anticipated. Essentially," substantially," "effective amount" are definite if one with ordinary skills would understand. Exemplary terminology is always indefinite such as, of hke material, similar— all rejected. 

Wave functions are also called orbitals. For convenience, chemists use the term orbital in several different ways. A drawing such as Figure 1.1 is often said to represent an orbital. We will see other kinds of drawings in this chapter, use the word orbital to describe them too, and accept some imprecision in language as the price to be paid for simplicity of expression. 

In 1960, Lotfi Zadeh proposed what he called Fuzzy Logic to describe the way people think and speak in their natural language. Fuzzy set theory creates classes or groupings of data with boundaries not sharply defined. Fuzzy techniques are used to solve real-world problems where we must deal with imprecision in the variables and parameters that are measured... 

Finally, we want to indicate that a major source of students conceptual difficulties is the imprecise or inappropriate language used in textbooks. For instance, the confusing use of the term oxidation for a reaction such as ... 

The systematic Boyle also found rankling the imprecise language of chemical theorists of his day. To call the attention of his colleagues to these inconsistencies, he wrote in l66l the classic didactic dialog The Sceptical Chymist, In it Boyle used the familiar device of a conversation among a group of friends—Themistus (defender of the Aristotelian theory of four elements), Philoponus (defender of the Paracelsian theory of three), Eleutherius (an uncommitted participant), the recorder of the conversations (whose name is not disclosed), and Cameades (the skeptical chemist)—to attack both the Aristotelian and Paracelsian systems. 

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