569 research outputs found

    IUS/payload communication system simulator configuration definition study

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    The requirements and specifications for a general purpose payload communications system simulator to be used to emulate those communications system portions of NASA and DOD payloads/spacecraft that will in the future be carried into earth orbit by the shuttle are discussed. For the purpose of on-orbit checkout, the shuttle is required to communicate with the payloads while they are physically located within the shuttle bay (attached) and within a range of 20 miles from the shuttle after they have been deployed (detached). Many of the payloads are also under development (and many have yet to be defined), actual payload communication hardware will not be available within the time frame during which the avionic hardware tests will be conducted. Thus, a flexible payload communication system simulator is required

    Shuttle orbiter S-band payload communications equipment design evaluation

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    The analysis of the design, and the performance assessment of the Orbiter S-band communication equipment are reported. The equipment considered include: network transponder, network signal processor, FM transmitter, FM signal processor, payload interrogator, and payload signal processor

    An ecological study of moorland enchytraeidae

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    Shuttle payload S-band communications study

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    The work to identify, evaluate, and make recommendations concerning the functions and interfaces of those orbiter avionic subsystems which are dedicated to, or play some part in, handling communication signals (telemetry and command) to/from payloads (spacecraft) that will be carried into orbit by the shuttle is reported. Some principal directions of the research are: (1) analysis of the ability of the various avionic equipment to interface with and appropriately process payload signals; (2) development of criteria which will foster equipment compatibility with diverse types of payloads and signals; (3) study of operational procedures, especially those affecting signal acquisition; (4) trade-off analysis for end-to-end data link performance optimization; (5) identification of possible hardware design weakness which might degrade signal processing performance

    Shuttle orbiter S-band communications equipment design evaluation

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    An assessment of S-band communication equipment includes: (1) the review and analysis of the ability of the various subsystem avionic equipment designs to interface with, and operate on signals from/to adjoining equipment; (2) the performance peculiarities of the hardware against the overall specified system requirements; and (3) the evaluation of EMC EMI test results of the various equipment with respect to the possibility of mutual interferences

    How stakeholder participation can contribute to systematic reviews of complex interventions

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    Although patient and public involvement in research is a requirement for research funding in many countries, the knowledge base for how to effectively involve people—and evidence of the effectiveness of involvement—is weak. This article describes how methods used in participatory health research were used to involve patients, clients, providers and community health workers across all stages of a realist review. Sustained involvement enabled better identification of the components of the complex intervention of community-based peer support. It also challenged assumptions of how peer support is constructed, leading the review team to question whether the process of designing and implementing interventions has more influence on effectiveness than previously recognised in empirical studies. We conclude with a discussion on when sustained involvement should be used, and the challenges of incorporating it into the traditional researcher-led approach to systematic reviews

    Occupational Exposure to Hydrazine and Subsequent Risk of Lung Cancer: 50-Year Follow-Up

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    Hydrazine is carcinogenic in animals, but there is inadequate evidence to determine if it is carcinogenic in humans. This study aimed to evaluate the association between hydrazine exposure and the risk of lung cancer.The cause specific mortality rates of a cohort of 427 men who were employed at an English factory that produced hydrazine between 1945 and 1971 were compared with national mortality rates.By the end of December 2012 205 deaths had occurred. For men in the highest exposure category with greater than two years exposure and after more than ten years since first exposure the relative risks compared with national rates were: 0.85 (95% CI: 0.18-2.48) for lung cancer, 0.61 (95% CI: 0.07-2.21) for cancers of the digestive system, and 0.44 (95% CI: 0.05-1.57) for other cancers.After 50 years of follow up, the results provide no evidence of an increased risk of death from lung cancer or death from any other cause

    High Temperature Electron Localization in dense He Gas

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    We report new accurate mesasurements of the mobility of excess electrons in high density Helium gas in extended ranges of temperature [(26T77)K][(26\leq T\leq 77) K ] and density [(0.05N12.0)atomsnm3][ (0.05\leq N\leq 12.0) {atoms} \cdot {nm}^{-3}] to ascertain the effect of temperature on the formation and dynamics of localized electron states. The main result of the experiment is that the formation of localized states essentially depends on the relative balance of fluid dilation energy, repulsive electron-atom interaction energy, and thermal energy. As a consequence, the onset of localization depends on the medium disorder through gas temperature and density. It appears that the transition from delocalized to localized states shifts to larger densities as the temperature is increased. This behavior can be understood in terms of a simple model of electron self-trapping in a spherically symmetric square well.Comment: 23 pages, 13 figure

    Using argumentation to manage users' preferences

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    Argumentation has provided a means to deal with inconsistent knowledge. We explore the potential of argumentation to handle conflicting user preferences. Classical preference handling methods in Artificial Intelligence (AI) lack the ability to handle ambiguity and the evolution of preferences over time. Previous experiments conducted by the authors indicate the usefulness of argumentation systems to handle Ambient Intelligence (AmI) examples with the aforementioned characteristics. This paper explores a generalized framework that can be applied to handle user preferences in AmI. The paper provides an overall preference handling architecture which can be used to extend current argumentation systems. We show how the proposed system can handle multiple users with the introduction of personalised preference functions. We illustrate how user preferences can be handled in realistic ways in AmI environments (such as smart homes), by showing how the system can make decisions based on inhabitants’ preferences on lighting, healthy eating and leisure

    A survey on managing users' preferences in ambient intelligence

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    Understanding the importance of preference management in ambient intelligent environments is key to providing systems that are better prepared to meet users' expectations. This survey provides an account of the various ways that preferences have been handled in Artificial Intelligence. Our analysis indicates that most of those techniques lack the ability to handle ambiguity and the evolution of preferences over time. Further exploration shows that argumentation can provide a feasible solution to complement existing work. We illustrate our claim by using an intelligent environment case study
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