ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Mathematical and Computer Sciences (General); Aerospace Medicine; Numerical Analysis  (1)
  • Parasitoids  (1)
  • SPACE COMMUNICATIONS, SPACECRAFT COMMUNICATIONS, COMMAND AND TRACKING  (1)
  • Statistics and Probability; Aerospace Medicine  (1)
  • 1
    facet.materialart.
    Unknown
    In:  Other Sources
    Publication Date: 2019-07-13
    Description: The NASA Space Shuttle Orbiter presents some very challenging antenna design problems for the S-band Orbiter to ground and Orbiter to relay satellite communications links. The line of sight to the ground and/or relay satellite during the various mission phases dictates an almost omni-directional coverage requirement, but the circuit margins require at least a 3 dB gain over this same coverage region. In addition, the environmental conditions imposed by the Orbiter mission dictate a flush mounted rugged antenna design. A number of potential antenna designs have been evaluated and found not to meet the Orbiter requirements. A small passive array of cavity backed spirals was found to offer the most potential to meet the design requirements. New circuit margin requirements presently under study have forced the consideration of the use of an active transmit/receive phased array design that considerably complicates the antenna design, but provides more than 10 dB of additional gain for circuit margin improvement.
    Keywords: SPACE COMMUNICATIONS, SPACECRAFT COMMUNICATIONS, COMMAND AND TRACKING
    Type: National Telecommunications Conference; Dec 02, 1974 - Dec 04, 1974; San Diego, CA
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2019-08-13
    Description: The Integrated Medical Model (IMM) Project supports end user requests by employing the Integrated Medical Evidence Database (iMED) and IMM tools as well as subject matter expertise within the Project. The iMED houses data used by the IMM. The IMM is designed to forecast relative changes for a specified set of crew health and mission success risk metrics by using a probabilistic model based on historical data, cohort data, and subject matter expert opinion. A stochastic approach is taken because deterministic results would not appropriately reflect the uncertainty in the IMM inputs. Once the IMM was conceptualized, a plan was needed to rigorously assess input information, framework and code, and output results of the IMM, and ensure that end user requests and requirements were considered during all stages of model development and implementation, as well as lay the foundation for external review and application. METHODS: In 2008, the Project team developed a comprehensive verification and validation (VV) plan, which specified internal and external review criteria encompassing 1) verification of data and IMM structure to ensure proper implementation of the IMM, 2) several validation techniques to confirm that the simulation capability of the IMM appropriately represents occurrences and consequences of medical conditions during space missions, and 3) credibility processes to develop user confidence in the information derived from the IMM. When the NASA-STD-7009 (7009) [1] was published, the Project team updated their verification, validation, and credibility (VVC) project plan to meet 7009 requirements and include 7009 tools in reporting VVC status of the IMM. Construction of these tools included meeting documentation and evidence requirements sufficient to meet external review success criteria. RESULTS: IMM Project VVC updates are compiled recurrently and include updates to the 7009 Compliance and Credibility matrices. Reporting tools have evolved over the lifetime of the IMM Project to better communicate VVC status. This has included refining original 7009 methodology with augmentation from the HRP NASA-STD-7009 Guidance Document working group and the NASA-HDBK-7009 [2]. End user requests and requirements are being satisfied as evidenced by ISS Program acceptance of IMM risk forecasts, transition to an operational model and simulation tool, and completion of service requests from a broad end user consortium including operations, science and technology planning, and exploration planning. IMM v4.0 is slated for operational release in the FY015 and current VVC assessments illustrate the expected VVC status prior to the completion of customer lead external review efforts. CONCLUSIONS: The VVC approach established by the IMM Project of incorporating Project-specific recommended practices and guidelines for implementing the 7009 requirements is comprehensive and includes the involvement of end users at every stage in IMM evolution. Methods and techniques used to quantify the VVC status of the IMM Project represented a critical communication tool in providing clear and concise suitability assessments to IMM customers. These processes have not only received approval from the local NASA community but have also garnered recognition by other federal agencies seeking to develop similar guidelines in the medical modeling community.
    Keywords: Statistics and Probability; Aerospace Medicine
    Type: GRC-E-DAA-TN20377 , 2015 NASA Human Research Program Investigators'' Workshop; Jan 13, 2015 - Jan 15, 2015; Galveston, TX; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2019-08-13
    Description: Model and simulation (MS) credibility is defined as, the quality to elicit belief or trust in MS results. NASA-STD-7009 [1] delineates eight components (Verification, Validation, Input Pedigree, Results Uncertainty, Results Robustness, Use History, MS Management, People Qualifications) that address quantifying model credibility, and provides guidance to the model developers, analysts, and end users for assessing the MS credibility. Of the eight characteristics, input pedigree, or the quality of the data used to develop model input parameters, governing functions, or initial conditions, can vary significantly. These data quality differences have varying consequences across the range of MS application. NASA-STD-7009 requires that the lowest input data quality be used to represent the entire set of input data when scoring the input pedigree credibility of the model. This requirement provides a conservative assessment of model inputs, and maximizes the communication of the potential level of risk of using model outputs. Unfortunately, in practice, this may result in overly pessimistic communication of the MS output, undermining the credibility of simulation predictions to decision makers. This presentation proposes an alternative assessment mechanism, utilizing results parameter robustness, also known as model input sensitivity, to improve the credibility scoring process for specific simulations.
    Keywords: Mathematical and Computer Sciences (General); Aerospace Medicine; Numerical Analysis
    Type: GRC-E-DAA-TN20412 , NASA HRP Investigator''s Workshop; Jan 13, 2015 - Jan 15, 2015; Galveston, Texas; United States
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    BioControl 37 (1992), S. 565-574 
    ISSN: 1573-8248
    Keywords: Parasitoids ; host-feeding ; nectar ; pollen ; honeydew ; parasitoïde ; adulte ; régime alimentaire
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Description / Table of Contents: Résumé Malgré l'importance potentielle de la nutrition des adultes dans l'écologie des parasitoïdes, les connaissances relatives à la gamme d'aliments naturels qu'ils exploitent restent limitées à un petit nombre d'espèces. Nous donnons ici quelques indications simples pour déterminer l'étendue du régime alimentaire chez les parasitoïdes adultes, pour faciliter et en même temps encourager une recherche ultérieure sur cet aspect de la biologie des parasitoïdes.
    Notes: Abstract Despite the potential importance of adult nutrition in the ecology of parasitoids, information on the range of natural foods they exploit is confined to a relatively small number of species. We provide some simple guidelines for determining dietary range in adult parasitoids, both to facilitate and to encourage further research into this aspect of parasitoid biology.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...