2,216 research outputs found

    Summary of a Crew-Centered Flight Deck Design Philosophy for High-Speed Civil Transport (HSCT) Aircraft

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    Past flight deck design practices used within the U.S. commercial transport aircraft industry have been highly successful in producing safe and efficient aircraft. However, recent advances in automation have changed the way pilots operate aircraft, and these changes make it necessary to reconsider overall flight deck design. Automated systems have become more complex and numerous, and often their inner functioning is partially or fully opaque to the flight crew. Recent accidents and incidents involving autoflight system mode awareness Dornheim, 1995) are an example. This increase in complexity raises pilot concerns about the trustworthiness of automation, and makes it difficult for the crew to be aware of all the intricacies of operation that may impact safe flight. While pilots remain ultimately responsible for mission success, performance of flight deck tasks has been more widely distributed across human and automated resources. Advances in sensor and data integration technologies now make far more information available than may be prudent to present to the flight crew

    A Hybrid Quantum-Classical Paradigm to Mitigate Embedding Costs in Quantum Annealing

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    Despite rapid recent progress towards the development of quantum computers capable of providing computational advantages over classical computers, it seems likely that such computers will, initially at least, be required to run in a hybrid quantum-classical regime. This realisation has led to interest in hybrid quantum-classical algorithms allowing, for example, quantum computers to solve large problems despite having very limited numbers of qubits. Here we propose a hybrid paradigm for quantum annealers with the goal of mitigating a different limitation of such devices: the need to embed problem instances within the (often highly restricted) connectivity graph of the annealer. This embedding process can be costly to perform and may destroy any computational speedup. In order to solve many practical problems, it is moreover necessary to perform many, often related, such embeddings. We will show how, for such problems, a raw speedup that is negated by the embedding time can nonetheless be exploited to give a real speedup. As a proof-of-concept example we present an in-depth case study of a simple problem based on the maximum weight independent set problem. Although we do not observe a quantum speedup experimentally, the advantage of the hybrid approach is robustly verified, showing how a potential quantum speedup may be exploited and encouraging further efforts to apply the approach to problems of more practical interest.Comment: 30 pages, 6 figure

    Data Recovery at 41MI96 in Mills County, Texas

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    Prehistoric site 41MI96 in Mills County, Texas was subjected to archeological data recovery excavations by staff archeologists from the Archeological Studies Program of the Texas Department of Transportation (TxDOT) in May 1999. This work followed an initial environmental review by TxDOT personnel that concluded that a proposed bridge replacement and associated realignment of a county road (CSJ: 0923- 23-011) had a high probability to impact previously unrecorded archeological sites. Subsequently, an archeological impact evaluation was conducted by TxDOT staff archeologists, under the direction of Dr. G. Lain Ellis. TxDOT investigations were conducted under Texas Antiquities Committee Permit No. 2193 to perform data recovery efforts at 41MI96 prior to development impacts. In 2012, TRC Environmental Corporation (TRC) of Austin was contracted by the Environmental Affairs Division of TxDOT through Work Authorization 57-109SA003 to conduct analysis on the recovered remains and complete a technical report of TxDOT’s field investigations and TRC’s laboratory findings in fulfillment of TxDOTs’ Antiquities permit. Data recovery excavations consisted of the excavation of four mechanical trenches across two creek terraces (T1 and T2) and hand-excavations in two small blocks (Blocks 1 and 2) within the TxDOT right-of-way on the northwestern side of the project area. Hand-excavations in both blocks were initiated to target newly discovered burned rock concentrations encountered in the bottom of backhoe scrapings. A total 5.5 m3 of manualexcavation was completed, which was comprised of 16 total 1-by-1 m units, 11 in Block 1, and 5 in Block 2. Cultural materials were dominated by ca. 602 burned rocks and 2,846 pieces of lithic debitage, 89 informal and formal tools, but lacked diagnostic artifacts and faunal material. Six small, intact burned rock features were identified in Block 1 and were the focus of laboratory analyses. The scattered burned rocks and debitage from Block 2 were only tabulated and discussed in a general way, as TxDOT personnel believed they were in mixed context. The six small burned rock features ranged in size from 33 to 100 cm in diameter and represented four intact heating elements (two with basins and two without), plus two small burned rock discard piles. Radiocarbon dating of organic residues in nine burned rocks from five intact features indicates multiple occupations over a span of roughly 700 years from 820 to 1450 B.P. (cal A.D. 560 to 1270). The lack of recorded depth measurements for cultural materials, combined with limited sediment deposition between the successive occupations, prevented isolation of individual occupational episodes. The lack of discernible vertical separation in the prehistoric occupations reflects slow soil aggregation during this period, likely lengthy surface exposure and possible erosion between events, and soil conditions which may also account for a near absence of charcoal and other organic materials such as vertebrate remains. Four technical analyses (radiocarbon dating, starch grain, lipid residue, and high-powered usewear) focused on a limited suite of chipped stone tools, associated lithic debitage, and burned rocks collected from five of the six intact features in Block 1 in the T2 terrace. Starch grain analysis on fragments of 20 burned rocks from five features and 20 chipped stone tools from around the features in Block 1 yielded positive results from 47.5 percent of the specimens. Of considerable interest is the documentation, in addition to multiple grass species, of grains of the tropical cultigen maize (Zea mays) on two burned rocks each, from Features 2 and 3, plus on two edge-modified tools in the vicinity of those two features. One specific burned rock with a gelatinized maize starch grain on it was directly AMS dated to 980 ± 30 B.P. or cal A.D. 1020 to 1150. Some identified maize starch grains had been damaged through grinding, heating, and/or boiling, evidence of processing as a food resource. This indicates use of maize as a food resource in central Texas a number of centuries earlier than previously suspected. Lipid residue analysis on portions of the same 20 burned rocks from those five features yielded residues in 100 percent of the samples. The results indicate that both plant and animal products were present on all the rocks, with large herbivore lipids (likely bison or deer) present on at least one rock, and oily seed lipids present on at least three rocks. Residues from conifer wood products, here likely juniper trees, were present on 60 percent of the rocks, and indicate at least one specific wood species used to heat the rocks. High-powered microscopic use-wear analyses on 15 chert tools (11 edge-modified flakes, 2 biface fragments, and 2 complete choppers) revealed their use in processing wood, plants, bone, and hide as well as unspecified soft and hard materials. The sparse frequency of formal chipped stone tools likely reflects the limited area investigated and also the possibility that these occupations reflect low-intensity and short-term camps that focused on preparing and cooking a few food resources in heating facilities and the manipulation of other perishable resources. The lipid and starch analyses of the burned rocks provides important information concerning the resources cooked by the rocks in these small burned rock features, most significantly the presence of maize and wild native grasses. These resources would have gone unidentified without these specialized analyses. Continued use of these two analytical techniques on suites of burned rocks from other features/sites in and around central Texas will provide an empirical basis for identifying changes in subsistence patterns over time and across geographical space. It is also notable that direct radiocarbon dating of organic residues contained within the porous sandstone burned rocks here has succeeded in providing satisfactory chronological control for the features and site, strongly indicating that this technique can be beneficially employed in the future in cases where other organics such as wood charcoal, charred seeds/nuts, and/or bone are unavailable for absolute dating. In 1999 the Texas Historical Commission accepted TxDOT’s field investigations as sufficient and concurred with TxDOT’s recommendation that no further work was necessary under Texas Antiquities Committee Permit No. 2193. Parts of site 41MI96 outside the current TxDOT right-of-way have not been fully evaluated. Based on the present findings and the excavated intact features in Block 1, it appears that potentially eligible deposits may be present beyond the current right-of-way. If TxDOT further expands this county road, it is recommended that those areas at 41MI96 be evaluated prior to surface modifications related to that project

    Six-Dimensional Yang Black Holes in Dilaton Gravity

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    We study the six-dimensional dilaton gravity Yang black holes of hep-th/0607193, which carry (1,-1) charge in SU(2)xSU(2) gauge group. We find what values of the asymptotic parameters (mass and scalar charge) lead to a regular horizon, and show that there are no regular solutions with an extremal horizon.Comment: 10 pages, 8 EPS graph

    A cross-sectional study of traditional Chinese medicine practitioner’s knowledge, treatment strategies and integration of practice of chronic pelvic pain in women

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    Background: Chronic pelvic pain (CPP) in women is persistent, intermittent cyclical and non-cyclical lower abdominal pain, lasting for more than 6 months. Traditional Chinese Medicine (TCM) is a popular treatment option for women’s health conditions, but little is known about how treatment for CPP is delivered by TCM practitioners. The aim of this survey was to explore practitioners understanding and treatment of women with CPP, and how they integrate their management and care into the health care system. Method: An online cross-sectional survey of registered TCM practitioners in Australia and New Zealand between May and October 2018. Survey domains included treatment characteristics (e.g. frequency), evaluation of treatment efficacy, referral networks, and sources of information that informed clinical decision making. Results: One hundred and twenty-two registered TCM practitioners responded to this survey, 91.7% reported regular treatment of women with CPP. Treatment decisions were most-often guided by a combination of biomedical and TCM diagnosis (77.6%), and once per week was the most common treatment frequency (66.7%) for acupuncture. Meditation (63.7%) and dietary changes (57.8%) were other commonly used approaches to management. The effectiveness of treatment was assessed using multiple approaches, most commonly pain scales, (such as the numeric rating scale) and any change in use of analgesic medications. Limitations to TCM treatment were reported by over three quarters (83.7%) of practitioners, most commonly due to cost (56.5%) and inconvenience (40.2%) rather than safety or lack of efficacy. Sources informing practice were most often Integration within the wider healthcare system was common with over two thirds (67.9%) receiving referrals from health care providers. Conclusion: TCM practitioners seeing women with various CPP symptoms, commonly incorporate both traditional and modern diagnostic methods to inform their treatment plan, monitor treatment progress using commonly accepted approaches and measures and often as a part of multidisciplinary healthcare for women with CPP

    Software-Defined Radio for Space-to-Space Communications

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    A paper describes the Space- to-Space Communications System (SSCS) Software- Defined Radio (SDR) research project to determine the most appropriate method for creating flexible and reconfigurable radios to implement wireless communications channels for space vehicles so that fewer radios are required, and commonality in hardware and software architecture can be leveraged for future missions. The ability to reconfigure the SDR through software enables one radio platform to be reconfigured to interoperate with many different waveforms. This means a reduction in the number of physical radio platforms necessary to support a space mission s communication requirements, thus decreasing the total size, weight, and power needed for a mission
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