Logic System

Prasanna de Silva, Nathan D. McClenaghan, and Colin P. McCoy 

Green plant photosynthesis, which feeds the world, runs on photoinduced electron transfer (PET). 121 This principle was developed in chemical contexts by Albert Weller over three decades ago, 131 and became adapted for use in fluorescent switching contexts in the late 1970s and early 1980s. 14-211 A general design principle emerged soon afterwards. 221 

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One variation of rule-based systems are fuzzy logic systems. These programs use statistical decision-making processes in which they can account for the fact that a specific piece of data has a certain chance of indicating a particular result. All these probabilities are combined in order predict a final answer. 

In statements 1 and 2, "For all" is a quantifier, specifically, the universal quantifier Water is a constant A is a variable and Liquid and Flow are predicates. Both statements 1 and 2 are asserted to be tme. First-order predicate logic gets its name because predicates such as Liquid and Flow are allowed, and quantification is only allowed on variables, not predicates. Having represented these facts in the logic system, the system can then be queried ... 

While such models of depression are quite useful in conceptualizing the mechanisms behind antidepressant activity, they are assuredly an oversimplification of the actual pathophysiologic process of the disorder. Depression probably involves a complex dysregulation of monoamine systems, and these systems, in turn, modulate and are modulated by other neurobio-logic systems. Thus, the underlying cause of depression may well extend beyond dysfunction of the monoamine system.10... 

A defuzzifier is the opposite of a fuzzifier it maps the output sets into crisp numbers, which is essential if a fuzzy logic system is to be used to control an... 

As mentioned earlier, pneumatic and hydraulic systems have been extensively used in hazardous environments to provide the power necessary to move and drive machinery to complete needed tasks. Their use has demanded development of complex logic systems which involve the addition of valves and piping. These logic control systems are often hard to design, debug, construct, and maintain. 

It is very important that such molecular-level motions are accompanied by changes of some chemical or physical property of the system, resulting in a readout signal that can be used to monitor the operation of the machine. The reversibility of the movement ie, the possibility to restore the initial situation by means of an opposite stimulus, is an essential feature of a molecular machine. Since such induced motions correspond to a binary logic systems of this kind could also prove useful for information processing. 

G. Ashkenazy, Biochemical molecular logic systems structure and function, M.Sc. thesis, Technion (Israel Instimte of Technology), Haifa, Israel, 1992. 

Hydrocarbon molecules that have only single bonds (C—C) are known as saturated hydrocarbons, whereas unsaturated hydrocarbon molecules have double or triple bonds (C=C or C=C). A very logical system that assigns names to the structures of these types of hydrocarbons uses Greek prefixes to identify the number of carbon atoms in a particular type of hydrocarbon molecule (see Table 2.2). 

The (OCS)2 anion is the next logical system, taking us into the realm of polyatomic anions with rich photochemistry and more complex symmetry. (OCS)2 is an example of how dramatically the properties of a compound (e.g., carbonyl sulfide) may change upon electron capture and/or solvation. . .. 

There is no commonly accepted trivial nomenclature for the bi- and triflavonoids and higher oligomeric forms. Their full systematic names, not to mention their often complex common names, are extremely cumbersome. Geiger and Quinn have proposed a system that requires frequent reference for understanding and has become increasingly difficult to implement as the number of new compounds has grown. No doubt, the nomenclature of this class of compounds is in disarray and it depends on active researchers in the field to select a simple but logical system and then to use it consistently. 

The names of the elements (and many of the symbols used to represent them) are traditional, rather than part of a logical system. The electrical charges that the ions usually carry can be reasoned out, but chemists do not work through such reasoning every time they want to use the charges or talk about them they simply know them as characteristic properties. 

In 1928, A. M. Patterson, later one of the authors of the Ring Index, wrote Any attempt to construct a strictly logical system of names for the large number of parent ring systems now known seems impractical, at least as far as common use is concerned. 7 This sentiment is no less applicable today. For heterocycles in particular, the number of trivial names in current use is large. In the 1969 IUPAC Rules,6 63 trivially named heterocyclic skeletons with various degrees of unsaturation are listed, with a further 25 in the 1973 Tentative Rules (Section D).8 Chemical Abstracts nomenclature rules list 83 such skeletons with maximum unsaturation, many of which are not included by IUPAC. Thus, although systematic operations are often required to derive the name of a heterocyclic skeleton, the parent names to which these operations are applied are frequently trivial. 

TABLE II. Synthesis of a Logical System Leading to the Two Cycles Given in the Text... 

As for the second alternative, in the Pearce-Pratt experiment, we can objectively and precisely define what chance is and determine whether the results are significantly different from it. When you are guessing the identity of a deck of Zener cards (without looking at each card after guessing it), it is obvious (to scientifically accepted logic systems) that you have a l-in-5... 

O Shea (2006) has summarized the redox steps involved in the mobilization of arsenic in natural hydro-logic systems (Table 6.2). It should be noted that in natural environments, discrete redox zones are not always observable and redox disequilibrium can occur, thus complicating arsenic mobilization and resorption (Mukherjee, 2006). 

ND McClenaghan. Molecular Logic Systems. PhD thesis, Queen s University of Belfast, Northern Ireland, 1999. 

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