445 research outputs found

    Motion software for a synergistic six-degree-of-freedom motion base

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    Computer software for the conversion of fixed-base simulations into moving-base simulations utilizing a synergistic six-degree-of-freedom motion simulator has been developed. This software includes an actuator extension transformation, inverse actuator extension transformation, a centroid transformation, and a washout circuit. Particular emphasis is placed upon the washout circuitry as adapted to fit the synergistic motion simulator. The description of the washout circuitry and illustration by means of a sample flight emphasize that translational cue representation may be of good fidelity, but care in the selection of parameters is very necessary, particularly in regard to anomalous rotational cues

    Fundamental length in quantum theories with PT-symmetric Hamiltonians

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    The direct observability of coordinates x is often lost in PT-symmetric quantum theories. A manifestly non-local Hilbert-space metric Θ\Theta enters the double-integral normalization of wave functions ψ(x)\psi(x) there. In the context of scattering, the (necessary) return to the asymptotically fully local metric has been shown feasible, for certain family of PT-symmetric toy Hamiltonians H at least, in paper I (M. Znojil, Phys. Rev. D 78 (2008) 025026). Now we show that in a confined-motion dynamical regime the same toy model proves also suitable for an explicit control of the measure or width θ\theta of its non-locality. For this purpose each H is assigned here, constructively, the complete menu of its hermitizing metrics Θ=Θθ\Theta=\Theta_\theta distinguished by their optional "fundamental lengths" θ(0,)\theta\in (0,\infty). The local metric of paper I recurs at θ=0\theta=0 while the most popular CPT-symmetric hermitization proves long-ranged, with θ=\theta=\infty.Comment: 31 pp, 3 figure

    Description of a computer program and numerical techniques for developing linear perturbation models from nonlinear systems simulations

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    A numerical technique was developed which generates linear perturbation models from nonlinear aircraft vehicle simulations. The technique is very general and can be applied to simulations of any system that is described by nonlinear differential equations. The computer program used to generate these models is discussed, with emphasis placed on generation of the Jacobian matrices, calculation of the coefficients needed for solving the perturbation model, and generation of the solution of the linear differential equations. An example application of the technique to a nonlinear model of the NASA terminal configured vehicle is included

    Maximal rank for ΩPn

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    International Mathematical Forum, Vol. 6, 2011, no. 8, 389 - 398Full Tex

    On combining microRNA analysis with DNA profiling in a single stream process

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    MicroRNAs have a potential to be ideal forensic markers due to their small size (~22nt), high abundance per cell, and sensitive and specific PCR-based detection. Thousands of microRNAs are present in biological material and they are rich in information due to their tightly regulated and cell type specific expression. Their advantageous properties increase the chances of successful analysis from challenged crime scene samples. In addition, it has been demonstrated previously that informative microRNA expression levels can be obtained from common DNA extracts without a change in protocol and will likely be present in cold-case extracts too. Following an earlier pilot project on a single stream process with the integration of microRNA analysis into a DNA profiling multiplex, progress on this line of research is now presented. The small nucleolar RNAs SNORD7, SNORD44, SNORD47 and the microRNA hsa-miR-93-5p have been identified as endogenous controls. These endogenous controls have been used real-time PCR experiments - in combination with results from other research groups in - to determine a larger panel of microRNAs that allow differentiation between blood, saliva, vaginal material and mixtures thereof. With the markers identified, the transition has been made to analysis by capillary electrophoresis. Here the analysis of the endogenous controls using capillary electrophoresis on ABI’s 3130 genetic analyser is presented and the effects of combining their analysis with genomic DNA human identification STR markers in a single reaction are explored. The endogenous control markers are reverse transcribed using a multiplex stem-loop reverse transcription, followed by multiplex PCR with labelled primers for the cDNA and genomic DNA markers simultaneously. This approach was demonstrated before, when it was shown that blood and saliva can successfully be distinguished by amplifying hsa-miR-451a and hsa-miR-205 cDNA during DNA profiling. This will now be expanded with our newly identified endogenous controls. Future work will include the incorporation of the additional body fluid specific markers, working towards a single reaction that can provide a DNA profile and body fluid identification on single source and mixed samples

    Fundamental length in quantum theories with PT-symmetric Hamiltonians II: The case of quantum graphs

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    Manifestly non-Hermitian quantum graphs with real spectra are introduced and shown tractable as a new class of phenomenological models with several appealing descriptive properties. For illustrative purposes, just equilateral star-graphs are considered here in detail, with non-Hermiticities introduced by interactions attached to the vertices. The facilitated feasibility of the analysis of their spectra is achieved via their systematic approximative Runge-Kutta-inspired reduction to star-shaped discrete lattices. The resulting bound-state spectra are found real in a discretization-independent interval of couplings. This conclusion is reinterpreted as the existence of a hidden Hermiticity of our models, i.e., as the standard and manifest Hermiticity of the underlying Hamiltonian in one of less usual, {\em ad hoc} representations Hj{\cal H}_j of the Hilbert space of states in which the inner product is local (at j=0j=0) or increasingly nonlocal (at j=1,2,...j=1,2, ...). Explicit examples of these (of course, Hamiltonian-dependent) hermitizing inner products are offered in closed form. In this way each initial quantum graph is assigned a menu of optional, non-equivalent standard probabilistic interpretations exhibiting a controlled, tunable nonlocality.Comment: 33 pp., 6 figure

    Techniques for improved convergence in neighboring optimum guidance

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77140/1/AIAA-1969-888-643.pd

    A simulation study of curved, descending, decelerating, landing approaches for transport aircraft

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    A system which is capable of controlling an aircraft automatically along a curved, descending, decelerating approach was described. A simulation study was conducted to determine the necessary modifications to the basic flight-proven control system. This basic system is presently being used to accomplish straight-in automatic landing approaches on a short-haul transport aircraft (B-737 terminal configured vehicle). This study shows that both 3 deg (normal) and 5 deg (steep) approaches could be accomplished with only minor modifications to the basic control system

    Compensation based on linearized analysis for a six degree of freedom motion simulator

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    The inertial response characteristics of a synergistic, six-degree-of-freedom motion base are presented in terms of amplitude ratio and phase lag as functions of frequency data for the frequency range of interest (0 to 2 Hz) in real time, digital, flight simulators. The notch filters which smooth the digital-drive signals to continuous drive signals are presented, and appropriate compensation, based on the inertial response data, is suggested. The existence of an inverse transformation that converts actuator extensions into inertial positions makes it possible to gather the response data in the inertial axis system

    24-month HIV-free survival among infants born to HIV-positive women enrolled in Option B+ program in Kigali, Rwanda: The Kabeho Study

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    Lifelong antiretroviral therapy (ART) provision to all pregnant HIV-positive women (“Option B+”) has been recommended by the World Health Organization since 2013, but there remain limited data on the effects of Option B+ on long-term HIV-free survival in breastfeeding HIV-exposed infants. The Kigali Antiretroviral and Breastfeeding Assessment for the Elimination of HIV (Kabeho) study enrolled HIV-positive women from the third trimester of pregnancy to 2 weeks postpartum in 14 heath facilities implementing Option B+ in Kigali, Rwanda. Mother–child pairs in the longitudinal observational cohort were followed until 24 months postpartum, with HIV diagnostic testing at 6 weeks, and 9, 18 and 24 months. The Kaplan–Meier method was used to estimate HIV transmission, survival, and HIV-free survival through 24 months. We enrolled 608 HIV-positive women in 2013–2014; birth outcome data were available for 600 women and 597 live-born infants. By 6 weeks, 11 infants had died and 3 infants had confirmed HIV infection (0.5% transmission; 95% confidence interval [CI] 0.2–1.6). At 9 months, there were 9 additional deaths and 2 new infections (cumulative transmission 0.9%, 95% CI 0.4–2.2). At 18 months, there were 6 additional deaths and no new infant infections. At 24 months, there were no additional child deaths and 1 new infection (cumulative 2.2%, 95% CI 0.7–7.0), for an overall 24-month HIV-free survival of 93.2% (95% CI 89.5–95.6). Low transmission rates and high HIV-free survival at 24 months were achieved in breastfeeding infants of HIV-positive mothers receiving universal ART in urban health facilities in Rwanda, though vigilance on maintaining viral suppression for ART-experienced women is needed
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