645 research outputs found

    Integration of preference elicitation and the development of alternative forest plans : focusing on the requirements of the decision maker

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    Modern forest management frequently revolves around the concepts of developing strategic, tactical and operational level plans. These plans are developed through the use of simulation and optimization software, based on scientific models and mathematical programming. The optimal management schedule depends upon the decision maker(s) (DM) preferences. When developing forest plans for the DM(s) the method of acquiring preference information should be as value free as possible. To facilitate a DM-orientated approach, a selection of alternatives based on the acquired preferences should be made available to the DM so that a true choice can be made. The development of the forest plans should represent the desires and wishes of the forest owner at the time the plan is created. In order to balance the costs with the quality of the service provided, tools are required which develop client specific forest plans. The first objective of this thesis is to analyse different preference elicitation methods and study the impacts of information content on the selection of a plan. In papers I and II, plans were selected using an a posteriori method of preference elicitation. For paper III, preference elicitation was done in an interactive fashion, to develop an acceptable forest plan using both a priori and a posteriori preference elicitation methods. The second objective is to develop techniques for incorporating preference information into optimization methods. In paper IV, a series of goal programming models were used to incorporate the preference information from several DMs to generate a number of potentially desirable forest plans. Paper V develops a goal programming formulation which separates the treatment of different goals into two partitions; one strives to maintain the difference from the target for the goals in balance, the other strives to obtain the most efficient aggregate solution.Nykyaikainen metsäsuunnittelu keskittyy usein sellaisille käsitteellisille tasoille kuin strateginen, taktinen ja operatiivinen suunnittelu. Suunnitelmat on toteutettu käyttämällä simulointi- ja optimointiohjelmistoja, jotka perustuvat tieteellisiin malleihin ja matemaattiseen ohjelmointiin. Kuitenkin päätöksentekijän /jien (PT) preferenssit määrittelevät optimaalisen aikataulun metsänhoidolle. Metsäsuunnitelmia tuotettaessa menetelmän tulisi olla mahdollisimman vapaa suunnittelijan omista arvoista ja mielipiteistä. Jotta lähestymistapa olisi mahdollisimman PT-ystävällinen, pitäisi päätöksentekijälle esittää useita metsänsuunnittelun vaihtoehtoja, joiden perusteella PT voi tehdä aidosti henkilökohtaisen valintansa. Tuotettujen metsäsuunnitelmien tulisi vastata metsänomistajan sen hetkisiä toiveita ja mieltymyksiä. Jotta suunnitelmien kustannusten ja laadun välille saadaan tasapaino, tarvitsemme työkaluja joilla muokata metsäsuunnittelua paremmin asiakaslähtöiseksi. Tämän tutkimuksen ensimmäinen tavoite oli analysoida eri preferenssien hankintamenetelmiä, sekä selvittää saadun tiedon määrän vaikutus suunnitelman valintaan. Artikkeleissa I ja II suunnitelma valittiin a posteriori menetelmän avulla. Artikkelissa III preferenssien hankinta toteutettiin interaktiivisesti, siten, että hyväksyttävä metsäsuunnitelma saatiin aikaiseksi hyödyntämällä sekä a priori, että a posteriori preferenssien valintamenetelmiä. Tutkimuksen toinen tavoite oli kehittää tekniikoita, joilla sisällytetään preferenssitietoa osaksi optimointimenetelmiä. Artikkelissa IV on käytetty sarjaa tavoiteohjelmointimalleja, joiden tavoitteena oli sisällyttää preferenssitietoja useilta eri päätöksentekijöiltä, joiden pohjalta sitten tuotettiin useita PT:itä potentiaalisesti kiinnostavia metsäsuunnitelmia. Artikkeli V kehitti uuden tavan formuloida tavoiteohjelmoinnin tehtävä, , joka erottaa tavoitteiden käsittelyn kahteen osaan; toinen pyrkii löytämään mahdollisimman tasapainoisen ratkaisun ja toinen pyrkii löytämään kaikista tehokkaimman ratkaisuyhdistelmän

    Simplified models for multi-criteria decision analysis under uncertainty

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    Includes abstract.Includes bibliographical references.When facilitating decisions in which some performance evaluations are uncertain, a decision must be taken about how this uncertainty is to be modelled. This involves, in part, choosing an uncertainty format {a way of representing the possible outcomes that may occur. It seems reasonable to suggest {and is an aim of the thesis to show {that the choice of how uncertain quantities are represented will exert some influence over the decision-making process and the final decision taken. Many models exist for multi-criteria decision analysis (MCDA) under conditions of uncertainty; perhaps the most well-known are those based on multi-attribute utility theory [MAUT, e.g. 147], which uses probability distributions to represent uncertainty. The great strength of MAUT is its axiomatic foundation, but even in its simplest form its practical implementation is formidable, and although there are several practical applications of MAUT reported in the literature [e.g. 39, 270] the number is small relative to its theoretical standing. Practical applications often use simpler decision models to aid decision making under uncertainty, based on uncertainty formats that `simplify' the full probability distributions (e.g. using expected values, variances, quantiles, etc). The aim of this thesis is to identify decision models associated with these `simplified' uncertainty formats and to evaluate the potential usefulness of these models as decision aids for problems involving uncertainty. It is hoped that doing so provides some guidance to practitioners about the types of models that may be used for uncertain decision making. The performance of simplified models is evaluated using three distinct methodological approaches {computer simulation, `laboratory' choice experiments, and real-world applications of decision analysis {in the hope of providing an integrated assessment. Chapter 3 generates a number of hypothetical decision problems by simulation, and within each problem simulates the hypothetical application of MAUT and various simplified decision models. The findings allow one to assess how the simplification of MAUT models might impact results, but do not provide any general conclusions because they are based on hypothetical decision problems and cannot evaluate practical issues like ease-of-use or the ability to generate insight that are critical to good decision aid. Chapter 4 addresses some of these limitations by reporting an experimental study consisting of choice tasks presented to numerate but unfacilitated participants. Tasks involved subjects selecting one from a set of five alternatives with uncertain attribute evaluations, with the format used to represent uncertainty and the number of objectives for the choice varied as part of the experimental design. The study is limited by the focus on descriptive rather than real prescriptive decision making, but has implications for prescriptive decision making practice in that natural tendencies are identified which may need to be overcome in the course of a prescriptive analysis

    MULTIPLE-OBJECTIVE DECISION MAKING FOR AGROECOSYSTEM MANAGEMENT

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    Multiple-objective decision making (MODEM) provides an effective framework for integrated resource assessment of agroecosystems. Two elements of integrated assessment are discussed and illustrated: (1) adding noneconomic objectives as constraints in an optimization problem; and (2) evaluating tradeoffs among competing objectives using the efficiency frontier for objectives. These elements are illustrated for a crop farm and watershed in northern Missouri. An interactive, spatial decision support system (ISDSS) makes the MODEM framework accessible to unsophisticated users. A conceptual ISDSS is presented that assesses the socioeconomic, environmental, and ecological consequences of alternative management plans for reducing soil erosion and nonpoint source pollution in agroecosystems. A watershed decision support system based on the ISDSS is discussed.Agribusiness,

    State-of-the-Art Report on Systems Analysis Methods for Resolution of Conflicts in Water Resources Management

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    Water is an important factor in conflicts among stakeholders at the local, regional, and even international level. Water conflicts have taken many forms, but they almost always arise from the fact that the freshwater resources of the world are not partitioned to match the political borders, nor are they evenly distributed in space and time. Two or more countries share the watersheds of 261 major rivers and nearly half of the land area of the wo rld is in international river basins. Water has been used as a military and political goal. Water has been a weapon of war. Water systems have been targets during the war. A role of systems approach has been investigated in this report as an approach for resolution of conflicts over water. A review of systems approach provides some basic knowledge of tools and techniques as they apply to water management and conflict resolution. Report provides a classification and description of water conflicts by addressing issues of scale, integrated water management and the role of stakeholders. Four large-scale examples are selected to illustrate the application of systems approach to water conflicts: (a) hydropower development in Canada; (b) multipurpose use of Danube river in Europe; (c) international water conflict between USA and Canada; and (d) Aral See in Asia. Water conflict resolution process involves various sources of uncertainty. One section of the report provides some examples of systems tools that can be used to address objective and subjective uncertainties with special emphasis on the utility of the fuzzy set theory. Systems analysis is known to be driven by the development of computer technology. Last section of the report provides one view of the future and systems tools that will be used for water resources management. Role of the virtual databases, computer and communication networks is investigated in the context of water conflicts and their resolution.https://ir.lib.uwo.ca/wrrr/1005/thumbnail.jp

    Stochastic Multiattribute Acceptability Analysis: an application to the ranking of Italian regions

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    We consider the issue of ranking regions with respect to a range of economic and social variables. Departing from the current practice of aggregating different dimensions via an arithmetic mean, we instead use Stochastic Multiattribute Acceptability Analysis (SMAA). SMAA takes account of the “whole space” of weights for the considered dimensions. Thus, rather than considering an average person giving equal or fixed weights to all dimensions, SMAA explores how potential differences in individual preferences affect the outcome. In this sense, in contrast to the purported objectivity of the many rankings supplied by economic institutions and mass media, this proposal enhances, simplifies and renders transparent the ranking exercise. The methodology is applied to the ranking of Italian regions, unveiling patterns of similarity and dissimilarity even within the same broad regional economy. Many of these findings are neglected within the extant literature addressing the “Mezzogiorno” problem
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