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  • Resource limited competition of two species : a dynamic model of a perturbed neutrally stable system

    Creator:
    Peterson, Bruce Alan, 1947-
    Abstract:
    An hierarchically structured resource flow competition model for two species is developed. The model is shown to be intrinsically neutrally stable with a dynamical behavior derived from perturbation responses. The model properties are contrasted with those of a conventionally interpreted Lotka-Volterra competition model. A simulation developed from the model is...
    Resource Type:
    Dissertation
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    terms of a series approximation to a more complex model. This mathematical approach has been used

  • The use of logistic regression for developing habitat association models

    Creator:
    Sjamsoe'oed, Roza
    Abstract:
    Quantitative habitat models of wildlife-habitat relationships are developed to formalize our current understanding about an ecological system. A habitat association model is one of these models that is useful for answering questions about how the habitat is occupied, how much growth habitat is required by the animal, or how the...
    Resource Type:
    Dissertation
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    habitat association model is one of these models that is useful for answering questions about how the

  • Hydrology and thermomechanics of liquid-dominated hydrothermal systems in Iceland

    Creator:
    Axelsson, Gudni
    Abstract:
    Low-temperature hydrothermal activity in Iceland is apparently mostly controlled by dikes and fractures. Conventional methods of production data analysis are not readily applicable in cases of heterogeneous/anisotropic fracture dominated hydrothermal systems. Moreover, the dikes and fractures may control the heat uptake mechanism of low-temperature activity. The free-surface response functions of...
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    Dissertation
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    . Based on a homogeneous and isotropic half- space model apparent permeability estimates of 0.7

  • Multi-objective Optimization of Reservoir Operation Under Uncertainty with Robust and Flexible Decision Variables

    Creator:
    Hosseini, Parnian
    Abstract:
    Optimization of reservoir operation is involves various competing objectives for a scarce resource (water). To find the optimal operation of reservoirs, it is essential to consider multiple objectives simultaneously. There are various sources of uncertainty associated with the reservoir operation problem that should be considered as well. The overarching goal...
    Resource Type:
    Dissertation
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    of decision variables. The proposed methodology is tested for two mathematical test problems and

  • Spatially explicit inter-temporal forest management decision under the risk of fire

    Creator:
    Konoshima, Masashi
    Abstract:
    This paper presents a framework for analyzing efficient spatial allocation of forest management efforts - fuel treatment and harvest - under the risk of fire. The framework integrates a fire behavior model and a spatially-explicit stochastic dynamic optimization model. I investigate the effects of spatial interaction across plots during forest...
    Resource Type:
    Dissertation
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    integrates a fire behavior model and a spatially-explicit stochastic dynamic optimization model. I

  • Modeling riparian zone processes : biomass production and grazing

    Creator:
    Korpela, Edwin J.
    Abstract:
    Seasonal trends in forage production and environmental parameters for five plant community types within a northeastern Oregon riparian zone were described and modeled using correlation and path analysis. Wet meadows produced the greatest amount of herbage biomass, followed by moist bluegrass meadows, gravel bars, forests and dry bluegrass meadows. Trends...
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    Dissertation
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    Community Designation 11 Field Sampling 11 Path Analysis 13 The Theoretical Model 17 Results and Discussion

  • Hierarchical analysis of spatial pattern and processes of Douglas-fir forests using wavelet analysis

    Creator:
    Bradshaw, G. A.
    Abstract:
    There has been an increased interest in the quantification of pattern in ecological systems over the past years. This interest is motivated by the desire to construct valid models which extend across many scales. Spatial methods must quantify pattern, discriminate types of pattern, and relate hierarchical phenomena across scales. Wavelet...
    Resource Type:
    Dissertation

  • Machine Learning Methods for Computational Sustainability

    Creator:
    Liu, Liping
    Abstract:
    Maintaining the sustainability of the earth’s ecosystems has attracted much attention as these ecosystems are facing more and more pressure from human activities. Machine learning can play an important role in promoting sustainability as a large amount of data is being collected from ecosystems. There are at least three important...
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    Dissertation
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    classification model for the learning problem. The thesis also analyzes the learnability of the superset label

  • The Factors Affecting the Diets of Groundfish in the Gulf of Alaska : Ecological and Modeling Considerations

    Creator:
    Thompson, Kevin A.
    Abstract:
    Marine systems undergo changes in community composition over time as a result of a variety of environmental and anthropogenic factors. Understanding these community changes and the factors that drive them is critical for ecosystem management of marine resources. The Gulf of Alaska (GOA) is a large marine ecosystem that includes...
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    Dissertation
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    changed the diets of key groundfish predators in the model based on our previous results for three

  • Age structure, developmental pathways, and fire regime characterization of Douglas-fir/western hemlock forests in the central western Cascades of Oregon

    Creator:
    Tepley, Alan J.
    Abstract:
    Descriptions of the fire regime in the Douglas-fir/western hemlock region of the Pacific Northwest traditionally have emphasized infrequent, predominantly stand-replacement fires and an associated linear pathway of stand development, where all stands proceed along a common pathway until reset by the next fire. Although such a description may apply in...
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    Dissertation
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    Cascade Range. Major objectives were to (1) develop a conceptual model of fire-mediated pathways of