ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    facet.materialart.
    Unknown
    Improving Information Extraction From Simulated Discharge Using Sensitivity-Weighted Performance Criteria (2021)
    Details
    Publication Date: 2021-10-28
    Description: Due to seasonal or interannual variability, the relevance of hydrological processes and of the associated model parameters can vary significantly throughout the simulation period. To achieve accurately identified model parameters, temporal variations in parameter dominance should be taken into account. This is not achieved if performance criteria are applied to the entire model output time series. Even when using complementary performance criteria, it is often only possible to identify some of the model parameters precisely. We present an innovative approach to improve parameter identifiability that exploits the information available regarding temporal variations in parameter dominance. Using daily parameter sensitivity time series, we construct a set of sensitivity-weighted performance criteria, one for each parameter, whereby periods of higher dominance of a model parameter and its corresponding process are assigned higher weights in the calculation of the associated performance criterion. These criteria are used to impose constraints on parameter values. We demonstrate this approach by constraining 12 model parameters for three catchments and examine ensemble hydrological simulations generated using these constrained parameter sets. The sensitivity-weighted approach improves in particular the identifiability for parameters whose corresponding processes are dominant only for short periods of time or have strong seasonal patterns. This results overall in slight improvement of model performance for a set of 10 contrasting performance criteria. We conclude that the sensitivity-weighted approach improves the extraction of hydrologically relevant information from data, thereby resulting in improved parameter identifiability and better representation of model parameters.
    Keywords: 551.48 ; parameter identifiability ; parameter constraints ; temporal diagnostic analysis ; sensitivity analysis ; performance criteria
    Language: English
    Type: map
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    CITATION GEO-LEO
  • 2
    facet.materialart.
    Unknown
    Carbides in iron-rich Fe-Mn-Cr-Mo-Al-Si-C systems (1984)
    In:  Other Sources
    Details
    Publication Date: 2019-06-28
    Description: The optimization of high carbon iron-base superalloy properties with duplex microstructure gamma + M7C3 carbide requires analysis in the context of a seven-component system. Data are first provided here for the Fe-Mn-Cr-Mo-C quinary system, at 30 at. pct carbon. A characterization of competing carbides, according to a pseudoternary phase diagram at 35 wt pct iron, is made from isothermal sections. It is noted that while M7C3 and M3C carbides' occurrences are respectively favored at the Cr and Mn corners, the M2C carbide and molybdenum cementite are predominant with increasing amounts of Mo. Lattice parameters are reported for the various carbides.
    Keywords: METALLIC MATERIALS
    Type: Journal of Materials Science (ISSN 0022-2461); 19; 965-973
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 3
    facet.materialart.
    Unknown
    Iron-base superalloys - A phase analysis of the multicomponent system (Fe-Mn-Cr-Mo-Nb-Al-Si-C) (1988)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: In the course of studies on the iron-rich multicomponent system Fe-Mn-Cr-Mo-Nb-Al-Si-C, work was concentrated on pertinent quinary and six-component combinations namely Fe-Mn-Al-Si-C, Fe-Cr-Al-Si-C and Fe-Mn-Cr-Al-Si-C which had been elaborated at 65, 72, and 80 wt pct Fe. Manganese acts as a strong stabilizer for the cementite carbide. Chromium seems to stabilize the iron aluminide Fe2Al5 which forms in a considerable amount within an alloy of nominal composition Fe(65)Mn(15)Cr(12)Al(5)Si(2)C(1) (percent by weight). Although the Mn3AlC carbide is, like Fe3AlC, a perovskite carbide, manganese does not appear to favor the formation of the perovskite carbide. Because of the relatively low sintering temperature (700 C), for al large portion of the samples equilibria conditions are not always reached.
    Keywords: METALLIC MATERIALS
    Type: Journal of Materials Science (ISSN 0022-2461); 23; 3113-311
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 4
    facet.materialart.
    Unknown
    Constructing multicomponent phase diagrams by overlapping ZPF lines (1986)
    In:  Other Sources
    Details
    Publication Date: 2019-07-12
    Description: A procedure is introduced which can be used to draw isothermal sections from a multicomponent phase diagram in a matter of minutes, regardless of the diagram complexity. In the proposed method, the zero phase fraction (ZPF) lines are drawn separately for all phases existing in the system; by overlapping these ZPF lines, the desired section is obtained. Two examples - with five components and eight components - are given to illustrate the method. Regarding the second example, it is noted that although the final diagram may be altered to create discontinuities in slope at intersection points, the diagram remains unchanged from a topological standpoint. Thus, the overlapping ZPF lines supply all the information needed to construct complex diagrams. Even if many more phases and components are involved, the final diagram can be drawn with equal facility.
    Keywords: METALLIC MATERIALS
    Type: Scripta Metallurgica (ISSN 0036-9748); 20; 889-894
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    NASA TECHNICAL REPORTS
  • 5
    facet.materialart.
    Unknown
    On characterizing the temporal dominance patterns of model parameters and processes (2016)
    In:  Hydrological Processes
    Details
    Publication Date: 2022-03-21
    Type: info:eu-repo/semantics/article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    CITATION PIK
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...