Adaptive Process Control with Fuzzy Logic and Genetic Algorithms

Researchers at the U.S. Bureau of Mines have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by modeling the search procedures of natural genetics. FLC's are rule based systems that efficiently manipulate a problem environment by modeling the 'rule-of-thumb' strategy used in human decision-making. Together, GA's and FLC's possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, an analysis element to recognize changes in the problem environment, and a learning element to adjust to the changes in the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented

Adaptive process control using fuzzy logic and genetic algorithms

Researchers at the U.S. Bureau of Mines have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by modeling the search procedures of natural genetics. FLC's are rule based systems that efficiently manipulate a problem environment by modeling the 'rule-of-thumb' strategy used in human decision making. Together, GA's and FLC's possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, and a learning element to adjust to the changes in the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented

One-loop vacuum polarization at mα7m\alpha^7 order for the two center problem

We present calculations of the one-loop vacuum polarization contribution (Uehling potential) for the two-center problem in the NRQED formalism. The cases of hydrogen molecular ions ($Z_1=Z_2=1$) as well as antiprotonic helium ($Z_1=2$, $Z_2=-1$) are considered. Numerical results of the vacuum polarization contribution at $m\alpha^7$ order for the fundamental transitions $(v=0,L=0)\to(v'=1,L'=0)$ in H$_2^+$ and HD$^+$ are presented.Comment: 6 pages, 2 figues, submitted to PR

Theoretical transition frequencies beyond 0.1 ppb accuracy in H2+_2^+, HD+^+, and antiprotonic helium

We present improved theoretical calculations of transition frequencies for the fundamental transitions $(L\!=\!0,v\!=\!1)\to(L'\!=\!0,v'\!=\!0)$ in the hydrogen molecular ions H$_2^+$ and HD$^+$ with a relative uncertainty $4\cdot10^{-11}$ and for the two-photon transitions in the antiprotonic helium atom with a relative uncertainty $10^{-10}$. To do that, the one-loop self-energy correction of order $\alpha(Z\alpha)^6$ is derived in the two Coulomb center approximation, and numerically evaluated in the case of the aforementioned transitions. The final results also include a complete set of other spin-independent corrections of order $m\alpha^7$. The leading order corrections of $\alpha^2\ln^3(Z\alpha)^{-2}(Z\alpha)^6$ are also considered that allows to estimate a magnitude of yet uncalculated contributions.Comment: 10 pages, 2 figure, to be submitted to PR

Hydrogen molecular ions for improved determination of fundamental constants

The possible use of high-resolution rovibrational spectroscopy of the hydrogen molecular ions H + 2 and HD + for an independent determination of several fundamental constants is analyzed. While these molecules had been proposed for metrology of nuclear-to-electron mass ratios, we show that they are also sensitive to the radii of the proton and deuteron and to the Rydberg constant at the level of the current discrepancies colloquially known as the proton size puzzle. The required level of accuracy, in the 10 --12 range, can be reached both by experiments, using Doppler-free two-photon spectroscopy schemes, and by theoretical predictions. It is shown how the measurement of several well-chosen rovibrational transitions may shed new light on the proton-radius puzzle, provide an alternative accurate determination of the Rydberg constant, and yield new values of the proton-to-electron and deuteron-to-proton mass ratios with one order of magnitude higher precision

Toxic properties of d-limonene in insects and the earthworm Eisenia fetida

The monocyclic hydrocarbon monoterpenoid, d-limonene, is the principal component of the essential oils of citrus. In recent years, it and similar compounds have been touted as possible alternatives to conventional insecticides. Studies were completed to determine the spectrum of insecticidal properties of d-limonene in several common insects via several routes of entry and to evaluate the suitability and efficacy of the compound as a general-use insecticide. Additionally, the effects of d-limonene on parameters of growth and reproduction in the German cockroach, Blattella germanica, were investigated. The toxic properties of d-limonene were also investigated in a non-target invertebrate, the earthworm Eisenia fetida. A non-invasive electrophysiological monitoring technique was used to assay for neurotoxicity effects of d-limonene in the earthworm;d-Limonene was not found to be a uniformly potent toxin against the insects tested. It exhibited no residual or oral toxicity, low topical toxicity, moderate fumigant and ovicidal activity, and significant repellency and larvicidal activity. The compound was synergized with piperonyl butoxide. The material was found to have interesting, subtle effects on insect growth and reproduction. It did not function as a feeding stimulant or arrestant, but significantly accelerated the growth rate of German cockroach nymphs when administered in the diet. Topical application of d-limonene to the oothecae of gravid German cockroaches caused embryotoxicity, and topical application of high levels to the female prior to mating was found to decrease reproductive potential and shorten the female lifespan. Neither pre-mating vapor exposure nor feeding of treated diet was found to influence reproduction;In the earthworm Eisenia fetida, d-limonene\u27s LC[subscript]50 was 6.0 ppm, and application of the synergists piperonyl butoxide and sesame oil did not affect toxicity significantly. A variety of behavioral, morphological, and neurobiological effects ensued rapidly following exposure, and the neurotoxic effects were regionally specific. Nervous system effects such as giant fiber conduction velocity decreases, medial giant fiber impulse rebounding, and spontaneous spiking of lateral giant fibers were noted following d-limonene treatment, but the effects were reversed once exposure ceased

High accuracy results for the energy levels of the molecular ions H2+, D2+ and HD+, up to J=2

We present a nonrelativistic calculation of the rotation-vibration levels of the molecular ions H2+, D2+ and HD+, relying on the diagonalization of the exact three-body Hamiltonian. The J=2 levels are obtained with a very high accuracy of 10^{-14} a.u. (for most levels) representing an improvement by five orders of magnitude over previous calculations. The accuracy is also improved for the J=1 levels of H2+ and D2+ with respect to earlier works. Moreover, we have computed the sensitivities of the energy levels with respect to the mass ratios, allowing these levels to be used for metrological purposes.Comment: 11 page

Biophysics Research Support at NASA/MSFC

No abstract availabl

Research reports: 1985 NASA/ASEE Summer Faculty Fellowship Program

A compilation of 40 technical reports on research conducted by participants in the 1985 NASA/ASEE Summer Faculty Fellowship Program at Marshall Space Flight Center (MSFC) is given. Weibull density functions, reliability analysis, directional solidification, space stations, jet stream, fracture mechanics, composite materials, orbital maneuvering vehicles, stellar winds and gamma ray bursts are among the topics discussed

Research Reports: 1984 NASA/ASEE Summer Faculty Fellowship Program

A NASA/ASEE Summer Faulty Fellowship Program was conducted at the Marshall Space Flight Center (MSFC). The basic objectives of the programs are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of the participants' institutions; and (4) to contribute to the research objectives of the NASA Centers. The Faculty Fellows spent ten weeks at MSFC engaged in a research project compatible with their interests and background and worked in collaboration with a NASA/MSFC colleague. This document is a compilation of Fellows' reports on their research during the summer of 1984. Topics covered include: (1) data base management; (2) computational fluid dynamics; (3) space debris; (4) X-ray gratings; (5) atomic oxygen exposure; (6) protective coatings for SSME; (7) cryogenics; (8) thermal analysis measurements; (9) solar wind modelling; and (10) binary systems