1,783 research outputs found

    Airborne Advanced Reconfigurable Computer System (ARCS)

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    A digital computer subsystem fault-tolerant concept was defined, and the potential benefits and costs of such a subsystem were assessed when used as the central element of a new transport's flight control system. The derived advanced reconfigurable computer system (ARCS) is a triple-redundant computer subsystem that automatically reconfigures, under multiple fault conditions, from triplex to duplex to simplex operation, with redundancy recovery if the fault condition is transient. The study included criteria development covering factors at the aircraft's operation level that would influence the design of a fault-tolerant system for commercial airline use. A new reliability analysis tool was developed for evaluating redundant, fault-tolerant system availability and survivability; and a stringent digital system software design methodology was used to achieve design/implementation visibility

    An Environmental Study of the Origin, Distribution, and Bioaccumulation of Selenium in Kentucky and Barkley Lakes

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    Many samples of water, bottom sediment, and fish were analyzed for toxic metal ion content. The samples were collected from several selected sites along Kentucky and Barkley Lakes as well as the Cumberland River and several sub-impoundments along these aquatic systems. Emphasis was placed on selenium, although several other metal ions were determined. The results showed that there are no serious pollution problems with As, Cd, Cr, Cu, Hg, Pb, Se, Sr, Zn, or Zr at any of the sites examined. Actually, none of the trace metals examined even come close to the EPA limits on fish, with the exception of lead in the White Crappie and mercury in the Bass. There appears to be no serious problem with lead in White Crappie as only two fish out of a total of nineteen were above the limit of 2 PPM. The same holds for mercury in the bass as only three fish out of thirty four were above the 0.5 PPM level. Water and sediment analyses for the above mentioned metal ions fell well within expected normal limits for unpolluted fresh water systems. No point sources could be identified for any of the metal ions. This is in contrast with results obtained on the lower Tennessee River by Hancock, et al. in which a large chemical complex was found to contribute significant quantities of trace metals. No significant seasonal variation of trace element content was observed in any of the sample types. Since the selenium content of all samples was so low, no laboratory bioaccumulation data were obtained. No general correlation between fish length and trace element content could be established, although there was a relationship for some elements, usually positive but sometimes negative. There was some correlation between trace element content and area and between elemental content and species of fish. However, these relationships are complex and depend on the trace element studied. The most important conclusion to be drawn from this study is that at this time there appears to be little problem with trace metal pollution in Kentucky and Barkley Lakes

    What Trump’s Picks for the Presidential Medal of Freedom Say about Him

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    President Donald Trump awarded his first ever Presidential Medals of Freedom this month to seven recipients: Babe Ruth, Elvis Presley, Antonin Scalia, Orrin Hatch, Roger Staubach, Alan Page and Miriam Adelson. It is the nation’s highest civilian honor. These ceremonies, which normally occur once or twice per year, provide Americans with an opportunity to celebrate the achievements of various people who have made an important contribution to U.S. culture. Because the president selects recipients with total discretion – American or otherwise, living or dead –- this award also says a lot about the president himself. What achievements or contributions does the president consider important? What groups of people most easily win his favor? And how does he hope to shape his legacy, judging by the company that he chooses to keep? To find out, we’ve analyzed every Presidential Medal of Freedom ever awarded, and the presidents who awarded them – including Trump

    Strategic Shift to a Diagnostic Model of Care in a Multi-Site Group Dental Practice.

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    BackgroundDocumenting standardized dental diagnostic terms represents an emerging change for how dentistry is practiced. We focused on a mid-sized dental group practice as it shifted to a policy of documenting patients' diagnoses using standardized terms in the electronic health record.MethodsKotter's change framework was translated into interview questions posed to the senior leadership in a mid-size dental group practice. In addition, quantitative content analyses were conducted on the written policies and forms before and after the implementation of standardized diagnosis documentation to assess the extent to which the forms and policies reflected the shift. Three reviewers analyzed the data individually and reached consensuses where needed.ResultsKotter's guiding change framework explained the steps taken to 97 percent utilization rate of the Electronic Health Record and Dental Diagnostic Code. Of the 96 documents included in the forms and policy analysis, 31 documents were officially updated but only two added a diagnostic element.ConclusionChange strategies established in the business literature hold utility for dental practices seeking diagnosis-centered care.Practical implicationsA practice that shifts to a diagnosis-driven care philosophy would be best served by ensuring that the change process follows a leadership framework that is calibrated to the organization's culture

    Quantum critical behavior in the heavy Fermion single crystal Ce(Ni0.935_{0.935}Pd0.065_{0.065})2_2Ge2_2

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    We have performed magnetic susceptibility, specific heat, resistivity, and inelastic neutron scattering measurements on a single crystal of the heavy Fermion compound Ce(Ni0.935_{0.935}Pd0.065_{0.065})2_2Ge2_2, which is believed to be close to a quantum critical point (QCP) at T = 0. At lowest temperature(1.8-3.5 K), the magnetic susceptibility behaves as χ(T)χ(0)\chi(T)-\chi (0) \propto T1/6T^{-1/6} with χ(0)=0.032×106\chi (0) = 0.032 \times 10^{-6} m3^3/mole (0.0025 emu/mole). For T<T< 1 K, the specific heat can be fit to the formula ΔC/T=γ0T1/2\Delta C/T = \gamma_0 - T^{1/2} with γ0\gamma_0 of order 700 mJ/mole-K2^2. The resistivity behaves as ρ=ρ0+AT3/2\rho = \rho_0 + AT^{3/2} for temperatures below 2 K. This low temperature behavior for γ(T)\gamma (T) and ρ(T)\rho (T) is in accord with the SCR theory of Moriya and Takimoto\cite{Moriya}. The inelastic neutron scattering spectra show a broad peak near 1.5 meV that appears to be independent of QQ; we interpret this as Kondo scattering with TK=T_K = 17 K. In addition, the scattering is enhanced near QQ=(1/2, 1/2, 0) with maximum scattering at ΔE\Delta E = 0.45 meV; we interpret this as scattering from antiferromagnetic fluctuations near the antiferromagnetic QCP.Comment: to be published in J. Phys: Conference Serie

    The Politics of the Presidential Medal of Freedom: A Fifty Year Analysis, 1963-2013

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    Established in 1963, the Presidential Medal of Freedom (PMOF) is the nation’s highest civilian honor. Presidents award the Medal at their discretion to “any person who has made an especially meritorious contribution to (1) the security or national interests of the United States, or (2) world peace, or (3) cultural or other significant public or private endeavors” (Executive Order 11085). Using an original database of all 1963-2013 PMOF recipients, we analyze how presidents exercise this symbolic unilateral power. In particular, we find that Democratic and Republican presidents differ in their recognition of various categories of achievement. Also, presidents have awarded a greater number of PMOFs annually in recent years, and it has become increasingly common to honor a large number of recipients in a single ceremony. While a strategic objective may be to attract positive media attention, our analysis indicates that PMOF ceremonies do not increase presidential approval ratings

    Stimulation of Adenosine A 3 Receptors in Cerebral Ischemia: Neuronal Death, Recovery, or Both?

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    The role of the adenosine A 3 receptor continues to baffle, and, despite an increasing number of studies, the currently available data add to, rather than alleviate, the existing confusion. The reported effects of adenosine A 3 receptor stimulation appear to depend on the pattern of drug administration (acute vs. chronic), dose, and type of the target tissue. Thus, while acute exposure to A 3 receptor agonists protects against myocardial ischemia, it is severely damaging when these agents are given shortly prior to cerebral ischemia. Mast cells degranulate when their A 3 receptors are stimulated. Degranulation of neutrophils is, on the other hand, impaired. While reduced production of reactive nitrogen species has been reported following activation of A 3 receptors in collagen-induced arthritis, the process appears to be enhanced in cerebral ischemia. Indeed, immunocytochemical studies indicate that both pre- and postischemic treatment with A 3 receptor antagonist dramatically reduces nitric oxide synthase in the affected hippocampus. Even more surprisingly, low doses of A 3 receptor agonists seem to enhance astrocyte proliferation, while high doses induce their apoptosis. This review concentrates on the studies of cerebral A 3 receptors and, based on the available evidence, discusses the possibility of adenosine A 3 receptor serving as an integral element of the endogenous cerebral neuroprotective complex consisting of adenosine and its receptors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75391/1/j.1749-6632.1999.tb07984.x.pd

    Reduction of the size of datasets by using evolutionary feature selection: the case of noise in a modern city

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    Smart city initiatives have emerged to mitigate the negative effects of a very fast growth of urban areas. Most of the population in our cities are exposed to high levels of noise that generate discomfort and different health problems. These issues may be mitigated by applying different smart cities solutions, some of them require high accurate noise information to provide the best quality of serve possible. In this study, we have designed a machine learning approach based on genetic algorithms to analyze noise data captured in the university campus. This method reduces the amount of data required to classify the noise by addressing a feature selection optimization problem. The experimental results have shown that our approach improved the accuracy in 20% (achieving an accuracy of 87% with a reduction of up to 85% on the original dataset).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. This research has been partially funded by the Spanish MINECO and FEDER projects TIN2016-81766-REDT (http://cirti.es), and TIN2017-88213-R (http://6city.lcc.uma.es)
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