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Thermoluminescence provides a method for studying properties of those crystalline imperfections which behave as electron traps and recombination centers in wide bandgap materials. This approach, however, has been used relatively little, possibly due to the fact that the shapes and intensities of thermoluminescent glow curves are functions of several experimental parameters and are often complicated by the overlapping of a number of individual glow peaks. In the present work, experimental parameters were isolated and some of their effects on thermoluminescent glow curves were analyzed. This yielded information on activation energies associated with trapping levels, the nature of the kinetics involved in electron transitions, and electron retrapping. A Type II-a diamond, which has a wide distribution of thermoluminescent glow peaks, was used in this work. (Author).
The theory of substitutions for Boolean formulas developed in a previous report is applied here to the determination of those s-tuples of formulas that may be allowable replacements for s -tuples of sub-formulas of given Boolean formulas. The criteria of allowability are very general and flexible, yet may be expressed with great precision and ease. The results formalize and extend various known isolated instances. They may be used for the study of a large number of problems in the theory and application of Boolean formulas and functions.
The state-logic relations are determined in an iterative structure for any autonomous sequential machine. A model (unlike that of Mealy) is used in which delay is distributed throughout the machine. Theorems are presented which prescribe the interconnection of identical elements to realize any autonomous sequential behavior. Synthesis, as described here, yields a more costly machine in terms of delay elements than those of previous workers. In addition to the iterative structure, increased speed of operation is the advantage bought by the extra delay elements.
It is well known that in communicating over randomly time-varying channels, a receiver which performs a channel measurement can make a better decision than one that does not. It is shown that a channel-measuring system improves system performance even when the channel characteristics are fixed only during the present message interval. The randomly time-varying channel studied is that of a Rayleigh fading medium with independently fading mark and space channels whose fading is fixed over one baud interval but is independent from baud to baud. The transmission system is a modified frequency shift keying (FSK) system such that during a portion of a baud interval the mark and space frequencies are always transmitted so as to act as reference signals. For the above system, the following characteristics have been established: (a) Optimum receiver configuration, (b) Optimum ratio alpha of information energy to total signal energy as a function of total available signal-to-noise ratio for a single fading channel, (c) Asymptotic optimum alpha for an M-diversity channel, (d) Error probabilities for (b) and asymptotic error probabilities for (c) for alpha opt as a function of total signal-to-noise ratio. The asymptotic results show that by using reference techniques the order of diversity is effectively doubled. (Author).