477 research outputs found

    Aircraft adaptive learning control

    Get PDF
    The optimal control theory of stochastic linear systems is discussed in terms of the advantages of distributed-control systems, and the control of randomly-sampled systems. An optimal solution to longitudinal control is derived and applied to the F-8 DFBW aircraft. A randomly-sampled linear process model with additive process and noise is developed

    Socio-demographic correlates, HIV/AIDS related cofactors, and measures of same-sex sexual behaviour among Northern Thai male soldiers

    No full text
    We use data from an anonymous self-administered 1991 survey of military personnel in northern Thailand to estimate overall levels of and socio-demographic differentials in same-sex sexual behaviour in this population. Additionally, we examine the relationship between sexual experience with another male and a variety of outcomes relevant to HIV prevention and policy. Overall, 16.3 per cent of the sexually active soldiers report ever having had anal or oral sex with other males. Same-sex sexual behaviour in this sample is positively associated with several indicators of higher socio-economic status. All of the men who report having had sex with other men report having had vaginal intercourse with females as well. Comparison of our estimate of same-sex sexual behaviour with those obtained from two similar samples drawn in 1991 suggests that the lower estimates observed in the other two studies are largely due to differences in data collection methods. Regarding the HIV/AIDS-related outcomes we examined, men who have had sex with other men are significantly more likely than those who have not to have ever injected drugs, to personally know someone with HIV/AIDS, to have had sex with a female prostitute in the last six months, and to have had a sexually transmitted disease in the last six months. In this sample, men who have had sex with other men are also less knowledgeable about HIV/AIDS than are men who have not. These results are discussed in terms of their implications for HIV-prevention policy in Thailand

    Dynamic Programming Solution for a Class of Pursuit Evasion Problems: The Herding Problem

    Full text link
    A herding dog and sheep problem is studied where the agent “dog” is considered the control action for moving the agent “sheep” to a fixed location using the dynamics of their interaction. The problem is solved for the deterministic case using dynamic programming. Proofs are provided for the correctness of the algorithms. The algorithm is analyzed for its complexity. A software package developed for experimentation is described

    Brief of Professors of Law, US v. Bergdahl

    Get PDF
    When scrutinizing executive actions for unlawful command influence, this Court must account for a president’s immense power over the military. The extant judicial test for unlawful command influence – a violation of due process in the military setting – is a contextual one, and hence must consider the unique and unparalleled authority of the Commander-In-Chief over the military and individual service-members when the president’s actions are at issue. This executive power should also be evaluated in light of its myriad, and historically important, constitutional and statutory constraints – some predating the birth of the United States – that appropriately continue to shape U.S. military law

    Abundance Analysis of the Extremely Fast ONeMg Novae V838 Herculis and V4160 Sagittarii

    Get PDF
    V838 Her and V4160 Sgr were two of the fastest classical novae ever observed, exhibiting light curve declines of 2 mag in less than 2 days. Both novae also showed strong neon emission lines, indicative of an outburst occurring on an oxygen-neon-magnesium white dwarf. Being the brighter of the two, V838 Her has an extensive set of X-ray to radio observations obtained during its first year after outburst. V4160 Sgr has a more modest set of ultraviolet and optical spectra, which show it to be similar to V838 Her, not just in its light curve evolution but also in its spectral development. The observed attributes imply that these novae occurred on extremely massive white dwarfs. This paper uses the Cloudy photoionization code to fit multiple epochs of emission line spectra to determine the elemental abundances of the ejecta of V838 Her and V4160 Sgr

    New Elemental Abundances for V1974 Cygni

    Full text link
    We present a new analysis of existing optical and ultraviolet spectra of the ONeMg nova V1974 Cygni 1992. Using these data and the photoionization code Cloudy, we have determined the physical parameters and elemental abundances for this nova. Many of the previous studies of this nova have made use of incorrect analyses and hence a new study was required. Our results show that the ejecta are enhanced, relative to solar, in helium, nitrogen, oxygen, neon, magnesium and iron. Carbon was found to be subsolar. We find an ejected mass of ~2x10e-4 solar masses. Our model results fit well with observations taken at IR, radio, sub-millimeter and X-ray wavelengths.Comment: 18 pages, 4 figures, accepted for publication in Ap

    Magnetic White Dwarfs from the SDSS II. The Second and Third Data Releases

    Full text link
    Fifty-two magnetic white dwarfs have been identified in spectroscopic observations from the Sloan Digital Sky Survey (SDSS) obtained between mid-2002 and the end of 2004, including Data Releases 2 and 3. Though not as numerous nor as diverse as the discoveries from the first Data Release, the collection exhibits polar field strengths ranging from 1.5MG to ~1000MG, and includes two new unusual atomic DQA examples, a molecular DQ, and five stars that show hydrogen in fields above 500MG. The highest-field example, SDSSJ2346+3853, may be the most strongly magnetic white dwarf yet discovered. Analysis of the photometric data indicates that the magnetic sample spans the same temperature range as for nonmagnetic white dwarfs from the SDSS, and support is found for previous claims that magnetic white dwarfs tend to have larger masses than their nonmagnetic counterparts. A glaring exception to this trend is the apparently low-gravity object SDSSJ0933+1022, which may have a history involving a close binary companion.Comment: 20 pages, 4 figures Accepted for publication in the Astronomical Journa

    Anopheles gambiae heat shock protein cognate 70B impedes o'nyong-nyong virus replication

    Get PDF
    Background Phylogenetic and functional analysis was conducted on an Anopheles gambiae gene, ENSANGG00000017398. Based on phylogenetic analysis, this gene belongs to the same lineage as Heat shock protein cognate 70-4 (Hsc70-4) in Drosophila. Accordingly, we propose to name this gene Heat shock protein cognate 70B (HSC70B). We previously reported that expression of HSC70B and other genes including elongation factor-1α (EF-1α) and the agglutinin attachment subunit (agglutinin) were up-regulated in o'nyong-nyong virus (ONNV)-infected female An. gambiae. Double-stranded RNA interferences have been applied to further investigate HSC70B, EF-1α and the agglutinin functions in ONNV replication in An. gambiae. Results Among these three RNAi silenced genes, only dsRNAs of HSC70B (dsHSC70B) promoted ONNV replication in adult An. gambiae compared to the control mosquitoes that were co-injected with ONNV and dsRNA of β-galactosidase (dsβ-gal). ONNV titers from mosquitoes co-injected with dsHSC70B were about 9-fold higher at 6 days post-injection (d.p.i.) as compared to the control mosquitoes. By using ONNV tagged with enhanced green fluorescent protein (ONNV-eGFP), co-injection of ONNV-eGFP with dsHSC70B also showed approximately 2 ~ 3-fold higher GFP expression rates than the controls in the head, thorax, and abdomen of the mosquito. Furthermore, co-injection of ONNV with dsHSC70B significantly reduced the lifespan of adult mosquitoes as compared with the control, co-injection of ONNV with dsβ-gal treated mosquitoes. Conclusion These results indicate that HSC70B plays important roles in homeostasis and suppression of ONNV replication in the vector, An. gambiae. Biological implications of these findings are that while mosquitoes allow ONNV to replicate in them, they also check viral titers so that ONNV infection will result in no harmful effect on mosquitoes. Therefore, mosquitoes can function as vectors of ONNV transmission to humans while ONNV infection in An. gambiae remains asymptomatic.We wish to thank Dr. K. E. Olson and B. D. Foy for his kind gift of infectious clone pONNic-Foy. This research would not have been possible without the assistance of Dr. Mabel Berois with helpful guide. This project was supported by grants R01-AI44273 from NIH/NIAID to F.H.C. D.L.V. was supported by NIH T32 A10753

    Biological Control Strategies for Mosquito Vectors of Arboviruses

    Get PDF
    Citation: Huang, Y.-J.S.; Higgs, S.; Vanlandingham, D.L. Biological Control Strategies for Mosquito Vectors of Arboviruses. Insects 2017, 8, 21.Historically, biological control utilizes predatory species and pathogenic microorganisms to reduce the population of mosquitoes as disease vectors. This is particularly important for the control of mosquito-borne arboviruses, which normally do not have specific antiviral therapies available. Although development of resistance is likely, the advantages of biological control are that the resources used are typically biodegradable and ecologically friendly. Over the past decade, the advancement of molecular biology has enabled optimization by the manipulation of genetic materials associated with biological control agents. Two significant advancements are the discovery of cytoplasmic incompatibility induced by Wolbachia bacteria, which has enhanced replacement programs, and the introduction of dominant lethal genes into local mosquito populations through the release of genetically modified mosquitoes. As various arboviruses continue to be significant public health threats, biological control strategies have evolved to be more diverse and become critical tools to reduce the disease burden of arboviruses
    • …
    corecore