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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Minimizacija odstupanja grupne od individualnih odluka primenom inteligentnih stohastičkih algoritama u problemima vodoprivrede i poljoprivrede / Minimization of distance between group and individualdecisions using intelligent stochastic algorithms for waterand agricultural management

Blagojević Boško 28 May 2015 (has links)
<p>Dono&scaron;enje odluka u poljoprivredi i vodoprivredi podrazumeva uvažavanje ekonomskih, dru&scaron;tvenih i&nbsp;kriterijuma za&scaron;tite životne sredine. Proces je složen jer se odluke zbog nemogućnosti kvantifikacije&nbsp;često donose na osnovu kvalitativnih podataka, ili jo&scaron; če&scaron;će, u kombinaciji sa postojećim kvantitativnim&nbsp;podacima. Analitički hijerarhijski proces (AHP) je teorijsko-metodolo&scaron;ki koncept vi&scaron;ekriterijumske<br />analize i optimizacije za podr&scaron;ku složenih procesa individualnog i grupnog odlučivanja, koji se pokazao&nbsp;kao jedan od najpogodnijih da podrži takve procese i zato je u svetu &scaron;iroko rasprostranjen. Kod&nbsp;odlučivanja u poljoprivredi i vodoprivredi, zbog složenosti procesa, podrazumeva se interdisciplinarni&nbsp;pristup sa uče&scaron;ćem vi&scaron;e interesnih strana (donosilaca odluka). Kod grupnih primena AHP, odluka se<br />najče&scaron;će dobija objedinjavanjem individualnih ocena ili objedinjavanjem individualnih prioriteta. U&nbsp;novije vreme AHP se sve vi&scaron;e kombinuje sa modelima za postizanje konsenzusa.<br />U disertaciji je predložen mogući novi način objedinjavanja individualnih odluka u grupnu zasnovan na&nbsp;minimizaciji odstupanja grupne od individualnih odluka. Ideja je da se na osnovu individualnih&nbsp;vrednovanja elemenata odlučivanja po metodologiji AHP generi&scaron;e grupni vektor pomoću algoritma&nbsp;simuliranog kaljenja (SA - simulated annealing) iz klase inteligentnih stohastičkih optimizacionih&nbsp;algoritama, posebno pogodnog kada re&scaron;enje treba tražiti u beskonačnim diskretnim prostorima. Po&scaron;to se<br />u AHP mogu koristiti različiti metodi za određivanje vektora prioriteta, koji se uobičajeno nazivaju&nbsp;&quot;prioritizacioni metodi&quot;, da bi se postupak objedinjavanja učinio nezavisnim od metoda prioritizacije, u&nbsp;disertaciji je definisan univerzalni pokazatelj grupne konzistentnosti nazvan grupno euklidsko rastojanje&nbsp;(GED - group Euclidean distance). Inteligentnim približavanjem grupnog vektora prioriteta&nbsp;individualnim odlukama, odnosno minimizacijom GED, identifikuje se grupni vektor koji dovoljno<br />dobro predstavlja individualne odluke. Predloženi postupak nazvan je metod SAAP (SA aggregation&nbsp;procedure). Za testiranje ispravnosti metoda SAAP kori&scaron;ćena su tri primera i rezultati predloženog&nbsp;metoda su poređeni sa rezultatima najče&scaron;će kori&scaron;ćenih kombinacija metoda grupnog objedinjavanja,<br />konsenzus modela i metoda prioritizacije koje su nazvane &scaron;eme objedinjavanja. Dobijeni rezultati su&nbsp;pokazali da je SAAP konkurentan sa ostalim &scaron;emama objedinjavanja.<br />U disertaciji je predložena i transparentna metodologija za grupno vi&scaron;ekriterijumsko ocenjivanje&nbsp;pogodnosti lokaliteta za navodnjavanje na datoj teritoriji. U FAO dokumentima je sugerisano da treba&nbsp;vr&scaron;iti ocenu pogodnosti lokaliteta za navodnjavanje a ne isključivo zemlji&scaron;ta i da treba uzeti u obzir sve<br />faktore (kriterijume) koji utiču na uspe&scaron;nost uvođenja navodnjavanja. Vi&scaron;ekriterijumsko određivanje&nbsp;pogodnosti lokaliteta za navodnjavanje je zasnovano na kombinaciji AHP i geografskog informacionog&nbsp;sistema (GIS) u grupnom kontekstu. Metodologija se sastoji iz četiri faze. U prvoj fazi se identifikuju&nbsp;podkriterijumi za određivanje pogodnosti lokaliteta za navodnjavanje od interesa za dato područje.<br />Podkriterijumi se zatim grupi&scaron;u u kriterijume (kao &scaron;to su osobine zemlji&scaron;ta, klima, socio-ekonomski&nbsp;kriterijum, tehničko-pravni kriterijum i za&scaron;tita životne sredine) i na taj način se formira hijerarhija&nbsp;problema odlučivanja. Identifikovani donosioci odluka vrednuju elemente hijerarhije, takođe po metodu&nbsp;AHP, a zatim se vrednovanja koriste za izračunavanje individualnih težina podkriterijuma.<br />Sastavni deo druge faze metodologije je predloženi vi&scaron;ekriterijumski metod za određivanje težina&nbsp;donosilaca odluka. Koristeći individualne težine podkriterijuma izračunate u prvoj i težine donosilaca&nbsp;odluka izračunate u ovoj fazi, &quot;otežanim&quot; aritmetičkim osrednjavanjem određuju se grupne (konačne&nbsp;težine) podkriterijuma (GIS slojeva). Da bi rastersko preklapanje slojeva bilo moguće, u trećoj fazi se<br />standardizuju GIS slojevi. Množenjem vrednosti piksela u svakom sloju sa pripadajućim grupnim&nbsp;težinama slojeva i njihovim sabiranjem dobija se konačna mapa pogodnosti lokaliteta za navodnjavanje i&nbsp;ona predstavlja osnovu za definisanje prostornih prioriteta izgradnje novih sistema za navodnjavanje na&nbsp;datom području. U četvrtoj fazi (analiza osetljivosti) se prvo isključuju slojevi koji predstavljaju<br />antropogene podkriterijume, a zatim i slojevi zasnovani na prirodnim &nbsp;karakteristikama. Na ovaj način se&nbsp;dobijaju dve nove mape pogodnosti lokaliteta za navodnjavanje koje pružaju dodatne informacije za&nbsp;definisanje prostornih prioriteta izgradnje novih sistema za navodnjavanje.</p> / <p>Agricultural and water management decision problems are usually complex because many criteria (such<br />as economical, social and environmental) need to be considered. For this kind of problems, decision<br />making process is often based only on qualitative data or sometimes on combination of quantitative and<br />qualitative data. The Analytic Hierarchy Process (AHP) is a multi criteria decision-making method that<br />has been used in many applications related with decision-making based on qualitative data, and is<br />applicable to both individual and group decision making situations. Because of the increasing<br />complexity of decision making problems in agriculture and water management and the necessity to<br />include all interested participants in problem solving, nowadays many AHP decision making processes<br />take place in group settings. There are various aggregation procedures for obtaining a group priority<br />vector within AHP-supported decision making, the most common of which are the aggregation of<br />individual judgments (AIJ), aggregation of individual priorities (AIP) and aggregations based on<br />consensus models.<br />A heuristic stochastic approach to group decision making is proposed in this dissertation as an<br />aggregation procedure which searches for the best group priority vector for a given node in an AHP&ndash;<br />generated hierarchy. The group Euclidean distance (GED) is used as a group consistency measure for<br />deriving the group priority vector for a given node in the AHP hierarchy where all participating<br />individuals already set their judgments. The simulated annealing (SA) algorithm tries to minimize the<br />GED, of the process of which can be considered an objective search for maximum consensus between<br />individuals within the group. The group priority vector obtained in this way is invariant to any<br />prioritization method; that is, there is no need to have individual priority vectors as is required by some<br />other aggregation procedures. This approach is named simulated annealing aggregation procedure<br />(SAAP). In order to check validity of this approach, three examples are used to compare it&#39;s results with<br />results obtained by various combinations of aggregations (AIJ and AIP), consensus models and<br />prioritization methods. In this dissertation, SAAP and other known combinations of aggregation<br />procedures and prioritization methods are labeled as aggregation schemes. Results shows that the SAAP<br />performs better or at least equally to several other well known combinations of prioritization and<br />aggregation in AHP group decision making frameworks.<br />The second objective of this dissertation was to establish a transferable and transparent procedure for<br />multi criteria group evaluations of land suitability for irrigation. The multi criteria approach is<br />recommended because according to FAO documents all aspects of the problem (environment, social<br />aspect, economy) need to be considered in the evaluation, not just soil. To make a decision on where to<br />build new, sustainable irrigation systems, here we propose multi criteria group decision making<br />approach which combines AHP and Geographic Information System (GIS). This approach is presented<br />as four-phase decision making framework. In the first phase, subcriteria relevant in validating land<br />suitability were grouped into five major criteria: soil, climate, economy, infrastructure and environment.<br />Considered as spatially determined decision making elements, criteria and subcriteria were evaluated<br />within the AHP framework by identified experts in the subject area.<br />In the second phase new multi criteria method is developed for deriving decision makers&#39; weights. Using<br />this weights and individual priority weights of subcriteria from first phase final group weights of<br />subcriteria (GIS layers) are computed. In third phase each subcriterion (GIS layer) is standardized. Then,<br />the cell values in each of the subcriterion layers are multiplied by the corresponding final weights of the<br />subcriteria and aggregated into the final land suitability maps for irrigation in GIS environment. Finally,<br />in the fourth phase, a sensitivity analysis is applied to check the influence of different criteria on the<br />result. By changing the weights of criteria, two more maps were generated showing land suitability for<br />irrigation regarding natural conditions and economy-water infrastructure.</p>
2

Biotehničke mere kao mogućnost za povećanje efikasnosti sistema za odvodnjavanje / Biotechnical measures as a possibility to increase the efficiency of drainage systems

Vranešević Milica 09 July 2015 (has links)
<p>Pojave ekstremnih padavina dovode do stvaranja vi&scaron;ka vode koji utiče na odvijanje stabilne poljoprivredne proizvodnje, ali i na životnu sredinu, ekonomiju i dru&scaron;tvo u celini. Uvođenjem biotehničkih mera u melioracionu praksu, kao dopunske mere na sistemima za odvodnjavanje, posledice prevlaživanja zemlji&scaron;ta mogle bi biti značajno umanjene. Sagledavanjem vremenske i prostorne pojave vi&scaron;ka vode na sistemima za odvodnjavanje primena biotehničkih mera može služiti, pored primarnog cilja, za postizanje povećanja efikasnosti sistema za odvodnjavanje, stabilizaciju obala, pobolj&scaron;anje kvaliteta vode u vodotocima, zatim za ostvarivanje optimalne &scaron;umovitosti, povećanje i stabilizaciju prinosa poljoprivrednih kultura, kao i povećanje biodiverziteta.<br />U radu primenjena je metodologija na osnovu koje je prikazano kako biotehničke mere mogu povećati efikasnost sistema za odvodnjavanje kroz smanjenje vremena potrebnog za evakuaciju sakupljenih i dovedenih vi&scaron;kova vode. Postupak određivanja povećanja efikasnosti podrazumeva odeđene korake. Prvi korak zasniva se na određivanju ključnih kriterijuma koji utiču na odabir lokaliteta za primenu biotehničkih mera. Da bi se dobili pouzdani i realni podaci potrebno je isključivanje subjektivnih ocena. To je postignuto primenom entropije odnosno objektivne metode za određivanje težinskih koeficijenata na osnovu kojih su kriterijumi za odabir pogodnosti lokaliteta izračunati. Sledeći korak podrazumeva određivanje vremena odvodnjavanja na osnovu merodavnih vi&scaron;kova vode koji se formiraju na sistemima pri različitim povratnim periodima. Poslednji korak odnosi se pre svega na zasnivanje biotehničkih mera na osnovu kojih se stvaraju uslovi za povećanje efikasnosti sistema za odvodnjavanje. Rezultati pogodnosti lokaliteta za primenu biotehničkih mera, vreme odvodnjavanja, kao i povećanje efikasnosti svih sistema za odvodnjavanje na teritoriji Vojvodine, izraženo kroz smanjenje potrebnog vremena odvodnjavanja, prikazani su kori&scaron;ćenjem geografsko informacionog sistema u vidu karata.<br />Primenom biotehničkih mera sprovodi multidisciplinaran pristup koji teži da zadovolji zainteresovane strane koje su u teoriji komplementarne, ali u realnosti obično u konfliktu. Dono&scaron;enje odluka gde, kakve i koji obim ovih mera primeniti trebalo bi da bude, od globalnog do lokalnog pristupa, &scaron;to stručnije bez ili sa minimalnim uticajem subjektivnih ocena, kao i sveobuhvatno i objektivno sagledavanje konkretnih i specifičnih problema koji vladaju na svakom sistemu za odvodnjavanje. Iako imaju mane, prednost uvođenja ovih mera ogleda se kroz jednostavnost primene u praksi u okvirima postojeće zakonske regulative, a na osnovu načela integralnosti, prevencije i predostrožnosti, očuvanja prirodnih resursa, održivog razvoja i primene podsticajnih mera.</p> / <p>Occasional extreme rainfall leads to the accumulation of excessive amount of water, which affects the course of the stable agricultural production, as well as the environment, economy and the society as a whole. Introducing biotechnical measures into the land reclamation procedure, as an additional measure in drainage systems, could significantly reduce the consequences of waterlogging. By perceiving the temporal and spatial appearance of excessive amount of water in drainage systems, the application of the biotechnical measures could, in addition to its primary goal, help achieve increased efficiency of drainage systems, stabilization of banks, improved water quality in watercourses, but also in achieving optimal density of area under forests, increase and stabilization of the agricultural crops&#39; yield, as well as increased biodiversity.<br />The methodology applied in this paper, based on which it was displayed how biotechnical measures could increase the efficiency of the drainage systems through reduction of the time needed for the evacuation of collected and imported excessive amount of water. Defining the procedure of efficiency increase includes certain steps. The first step is based on defining key criteria that influence the choice of locality for the biotechnical measures application. In order to obtain reliable and accurate data it is necessary to exclude subjective estimations. That is achieved with the application of the Entropy, an objective method for defining weight coefficients based on which the criteria for determining the suitability of the locality are calculated. Next step is defining the drainage time based on design excessive amount of water formed in systems with different return periods. The last step refers primarily on establishing biotechnical measures on the basis of which the conditions are created for increasing drainage systems&#39; efficiency. The results of suitability of the locality for the application of biotechnical measures, the time of drainage, as well the increase the efficiency of all the drainage systems on the territory of Vojvodina, expressed through the reduction of the necessary drainage time, are shown using Geographical Information System in forms of maps.<br />Application of biotechnical measures means implementing a multidisciplinary approach that strives to please interested parties which are complementary in theory, but in reality are usually conflicted. Deciding where, what kind and in which extend to apply these measures, from global to local approach, should be as professional as possible, without or with the minimal influence of subjective estimations, as well as comprehensive and objective overview of specific and particular problems that command over every draining system. Even though they have certain flaws, the advantage of introducing these measures is reflected in simplicity of practical application within the frame of existing legal regulation, and based on the principle of integrity, prevention and precaution, conservation of natural resources, sustainable development and implementation of incentive measures.</p>

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