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| Preface | |
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| Acknowledgments | |
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| Introduction | |
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| Common-sense solutions: three exercises | |
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| Modeling theory | |
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| Modeling practice | |
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| Theory, practice, and common sense | |
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| Intended use of this book | |
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| Common-sense solutions: three exercises | |
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| Common-sense solutions | |
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| Three problems | |
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| Harvesting food for the winter | |
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| Estimating the probability of population extinction | |
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| Managing the Commons | |
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| The systems approach to problem solving | |
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| The conceptual model (Phase I) | |
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| The quantitative model (Phase II) | |
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| Model evaluation (Phase III) | |
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| Model application (Phase IV) | |
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| The three problems revisited: the systems approach in theory and practice | |
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| Modeling theory | |
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| Theory I: the conceptual model | |
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| State the model objectives (I[subscript a]) | |
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| Bound the system-of-interest (I[subscript b]) | |
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| Categorize the components within the system-of-interest (I[subscript c]) | |
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| State variables | |
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| Material transfers | |
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| Sources and sinks | |
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| Information transfers | |
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| Driving variables | |
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| Constants | |
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| Auxiliary variables | |
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| Identify the relationships among the components that are of interest (I[subscript d]) | |
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| Submodels | |
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| Represent the conceptual model (I[subscript e]) | |
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| Conceptual-model diagrams | |
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| Describe the expected patterns of model behavior (I[subscript f]) | |
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| Theory II: the quantitative model | |
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| Select the general quantitative structure for the model (II[subscript a]) | |
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| Choose the basic time unit for the simulations (II[subscript b]) | |
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| Identify the functional forms of the model equations (II[subscript c]) | |
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| Information on which to base the choice of functional forms | |
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| Selecting types of equations to represent the chosen functional forms | |
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| Estimate the parameters of the model equations (II[subscript d]) | |
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| Statistical analyses within the context of simulation model parameterization | |
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| Quantifying qualitative information | |
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| Deterministic- versus stochastic-model parameterization | |
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| Execute the baseline simulation (II[subscript e]) | |
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| Baseline simulations for stochastic models | |
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| Theory III: model evaluation | |
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| Assess the reasonableness of the model structure and the interpretability of functional relationships within the model (III[subscript a]) | |
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| Evaluate the correspondence between model behavior and the expected patterns of model behavior (III[subscript b]) | |
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| Examine the correspondence between model projections and the data from the real system (III[subscript c]) | |
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| Quantitative versus qualitative model evaluation | |
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| Determine the sensitivity of model projections to changes in the values of important parameters (III[subscript d]) | |
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| Interpreting sensitivity analysis within a model evaluation framework | |
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| Theory IV: model application | |
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| Develop and execute the experimental design for the simulations (IV[subscript a]) | |
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| Analyze and interpret the simulation results (IV[subscript b]) | |
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| Communicate the simulation results (IV[subscript c]) | |
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| Modeling practice | |
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| Some common pitfalls | |
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| Phase I pitfalls: the conceptual model | |
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| Phase II pitfalls: the quantitative model | |
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| Phase III pitfalls: model evaluation | |
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| Phase IV pitfalls: model application | |
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| The modeling process in practice | |
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| Preliminary conceptual model (CM) | |
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| How to begin | |
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| Adding new components to the model | |
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| Describing expected patterns | |
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| Describing the plan of attack | |
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| Intermediate developmental models (IDM[subscript i]) | |
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| Evaluate-adjust cycle for each developmental model | |
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| Sensitivity analysis of the last developmental model | |
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| Final model (FM) | |
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| Theory, practice, and common sense | |
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| The common-sense problems revisted | |
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| Harvesting food for the winter | |
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| The preliminary conceptual model (CM) | |
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| The last (only) intermediate development model (IDM[subscript last]) | |
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| The final model (FM) | |
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| Estimating the probability of population extinction | |
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| The preliminary conceptual model (CM) | |
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| The intermediate development models (IDM[subscript i]) | |
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| The final model (FM) | |
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| Managing the Commons | |
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| The preliminary conceptual model (CM) | |
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| The intermediate development models (IDM[subscript i]) | |
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| The final model (FM) | |
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| Reflections | |
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| The systems approach as a complement to other methods of problem solving | |
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| Ecological modeling as a problem-solving process | |
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| Expectations for ecological models | |
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| A final thought | |
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| References | |
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| Introduction to the ecological modeling literature | |
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| Scientific reports for the examples in Chapter 2 | |
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| Effect of deforestation on rate of food harvest | |
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| Effect of hurricane frequency on probability of population extinction | |
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| Effect of stocking rate on forage and animal production | |
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| Index | |