4,259 research outputs found
Toward improved calibration of hydrologic models: Combining the strengths of manual and automatic methods
Automatic methods for model calibration seek to take advantage of the speed and power of digital computers, while being objective and relatively easy to implement. However, they do not provide parameter estimates and hydrograph simulations that are considered acceptable by the hydrologists responsible for operational forecasting and have therefore not entered into widespread use. In contrast, the manual approach which has been developed and refined over the years to result in excellent model calibrations is complicated and highly labor-intensive, and the expertise acquired by one individual with a specific model is not easily transferred to another person (or model). In this paper, we propose a hybrid approach that combines the strengths of each. A multicriteria formulation is used to "model" the evaluation techniques and strategies used in manual calibration, and the resulting optimization problem is solved by means of a computerized algorithm. The new approach provides a stronger test of model performance than methods that use a single overall statistic to aggregate model errors over a large range of hydrologic behaviors. The power of the new approach is illustrated by means of a case study using the Sacramento Soil Moisture Accounting model
DISCRET: An Interactive Decision Support System for Discrete Alternatives Multicriteria Problems
This paper is one of the series of 11 Working Papers presenting the software for interactive decision support and software tools for developing decision support systems. These products constitute the outcome of the contracted study agreement between the System and Decision Sciences Program at IIASA and several Polish scientific institutions. The theoretical part of these results is presented in the IIASA Working Paper WP-88-071 entitled "Theory, Software and Testing Examples in Decision Support Systems" which contains the theoretical and methodological backgrounds of the software systems developed within the project.
This paper presents the DISCRET system. This system has been designed to solve basic multicriteria choice problems in which a finite set of feasible alternatives is explicitly given and for each alternative the value of all criteria are known. The decision maker is assumed to be rational in the sense that he can accept a Pareto-optimal solution as his final solution of the problem.
Such a decision problem is rather simple as long as the number of criteria and alternatives is small. However, if the number of alternatives and/or criteria grows, the human information processing capabilities may reach their limits and therefore decision support facilities need to be utilized to guarantee efficient decision making
Participatory Modelling and Decision Support for Natural Resources Management in Climate Change Research
The ever greater role given to public participation by laws and regulations, in particular in the field of environmental management calls for new operational methods and tools for managers and practitioners. This paper analyses the potentials and the critical limitations of current approaches in the fields of simulation modelling (SM), public participation (PP) and decision analysis (DA), for natural resources management within the context of climate change research. The potential synergies of combining SM, PP and DA into an integrated methodological framework are identified and a methodological proposal is presented, called NetSyMoD (Network Analysis – Creative System Modelling – Decision Support), which aims at facilitating the involvement of stakeholders or experts in policy - or decision-making processes (P/DMP). A generic P/DMP is formalised in NetSyMoD as a sequence of six main phases: (i) Actors analysis; (ii) Problem analysis; (iii) Creative System Modelling; (iv) DSS design; (v) Analysis of Options; and (vi) Action taking and monitoring. Several variants of the NetSyMoD approach have been adapted to different contexts such as integrated water resources management and coastal management, and, recently it has been applied in climate change research projects. Experience has shown that NetSyMoD may be a useful framework for skilled professionals, for guiding the P/DMP, and providing practical solutions to problems encountered in the different phases of the decision/policy making process, in particular when future scenarios or projections have to be considered, such as in the case of developing and selecting adaptation policies. The various applications of NetSyMoD share the same approach for problem analysis and communication within the group of selected actors, based upon the use of creative thinking techniques, the formalisation of human-environment relationships through the DPSIR framework, and the use of multi-criteria analysis through a Decision Support System (DSS) software.Modelling, Public Participation, Natural Resource Management, Policy, Decision-Making, Governance, DSS
A Multicriteria Decision Support System MultiDecision-1
* This paper is partially supported by the National Science Fund of Bulgarian Ministry of Education and Science
under contract № I–1401\2004 "Interactive Algorithms and Software Systems Supporting Multicriteria Decision
Making."The present paper describes some basic elements of the software system developed (called
MultiDecision-1), which consists of two separate parts (the systems MKA-1 and MKO-1) and which is designed to
support decision makers in solving different multicriteria analysis and multicriteria optimization problems. The
class of the problems solved, the system structure, the operation with the interface modules for input data entry
and the information about DM’s local preferences, as well as the operation with the interface modules for
visualization of the current and final solutions for the two systems MKA-1 and MKO-1 are discussed
Selected Issues of Design and Implementation od Decision Support Systems
The paper presents selected issues related to design and implementation of model based Decision Support Systems (DSS). For over ten years the SDS Program has been involved in cooperation with various projects at IIASA and in collaborating research institutes. This cooperation has resulted in the development of many DSS, which in turn stimulated research on the theory and methodology of decision analysis. An overview of selected DDS developed within the cooperation with IIASA is presented. Different concepts of DSS are briefly discussed and one specific type of DSS, namely model based, aspiration-led DSS is characterized. Finally, selected problems of designing and implementation of a DSS are discussed in more detail. A short description of software packages developed within the cooperation with the MDA Project is provided. The paper also gives a short summary of recent activities of the Methodology of Decision Analysis Project and of the DSS software available from the MDA Project
Multicriteria mapping manual: version 1.0
This Manual offers basic advice on how to do multicriteria mapping (MCM). It suggests how to: go about designing and building a typical MCM project; engage with participants and analyse results – and get the most out of the online MCM tool. Key terms are shown in bold italics and defined and explained in a final Annex.
The online MCM software tool provides its own operational help. So this Manual is more focused on the general approach. There are no rigid rules. MCM is structured, but very flexible. It allows many more detailed features than can be covered here.
MCM users are encouraged to think for themselves and be responsible and creative
Comparative Performance of Selected Mathematical Programming Models
This study compares the predictive performance of several mathematical programming models. Using the cropping patterns, yields and crop gross margins of eighteen farms over a period of five years we compare the models' optimum solutions with observed crop distributions after the Reform of the EU Common Agricultural Policy of 1992. The results show that the best prediction corresponds to a model that includes expected profit and a qualitative measure of crop riskiness. The results suggest that, in order to obtain reliable predictions, the modelling of farmers' responses to policy changes must consider the risk associated with any given cropping pattern. Finally, we test the ability of the proposed model to reproduce the farmers' observed behaviour with equally good performance under conditions of limited data availability.model performance, mathematical programming, modelling, decision-making, Resource /Energy Economics and Policy,
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