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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.
81

[en] PERMEABILITY ESTIMATION IN TURBIDITE CHANNELS CONSTRAINED BY WELL-TESTING / [pt] ESTIMATIVA DA PERMEABILIDADE EM CANAIS TURBIDÍTICOS USANDO DADOS DE TESTE DE FORMAÇÃO

TAMIRES PEREIRA PINTO DA SILVA 08 January 2019 (has links)
[pt] O principal objetivo deste trabalho é preencher canais turbidíticos com alguma propriedade petrofísica, como a permeabilidade. Estes canais são geometricamente limitados por lobos turbidíticos, gerando a simulação de um sistema deposicional. Simulações numéricas são usadas para tentar ajustar a permeabilidade a um caso de referência por meio de uma função objetivo. Um simulador convencional de diferenças finitas foi usado para comparar os dados de referência com as simulações, obtendo resultados próximos. / [en] The main objective of this work is to populate turbidite channels with some petrophysical property such as permeability. These channels are geometrically constrained by turbidite lobes creating a simulated depositional system. Numerical simulations are used to try to fit the permeability field to a reference case through an objective function. A conventional finite difference simulator was used to compare the reference data to the simulations, obtaining close results.
82

Linkage Between Mangrove Fish Community and Nearshore Benthic Habitats in Biscayne Bay, Florida, USA: A Seascape Approach

Santos, Rolando O. 01 April 2010 (has links)
The role of mangroves as essential fish habitat has been a focus of extensive research. However, recent evidence has shown that this role should not be evaluated in isolation from surrounding habitats such as seagrass beds and hard-bottom communities. For example, submerged aquatic vegetation (SAV) communities provide potential sources of food and shelter for fish species that may reside in the mangroves, but may also undergo ontogenetic migrations and daily home-range movements into neighboring habitats. The connectivity between the mangrove fish community and the surrounding seascape may be influenced by the level of patchiness, fragmentation, and spatial heterogeneity of adjacent SAV habitats (i.e., SAV seascape structure). The spatial patterns and heterogeneity of SAV seascape structures are driven by internal and external regulatory mechanisms operating at different spatial and temporal scales. In addition, it is likely that many fish species inhabiting the mangrove zones have different home ranges, and foraging and migratory patterns; therefore, different mangrove fish species may respond to seascape heterogeneity at different scales. There are few studies that have assessed the influence and connectivity of benthic habitats adjacent to mangroves for estuarine fish populations at multiple scales. The present research used an exploratory seascape approach in Biscayne Bay (Florida, USA) to evaluate patterns in the patch composition and configuration of SAV communities, and to examine relationships between seascape structural metrics and the abundance, diversity, and distribution of fishes that utilize the adjacent mangrove shoreline as nursery and/or adult habitat. This seascape approach consisted of: a) the multi-scale characterization of the SAV distribution across the seascape with metrics developed in Landscape Ecology, Geographic Information Systems and Remote Sensing; b) multivariate analyses to identify groups with significantly distinct SAV seascape structures within the most heterogeneous scale, and identify possible mechanisms driving the observed SAV seascape structures; and c) an assessment of the mangrove fish community responses to SAV seascape structures. By applying a set of multivariate analyses (e.g., ANOSIM, MDS plots, hierarchical clustering), the buffer within 200 m from shore was identified as the scale with the highest structural heterogeneity. At this scale, two major SAV seascape structures (i.e., areas with similar SAV spatial arrangement and composition) were identified: a fragmented SAV seascape (FSS) structure and a continuous SAV seascape (CSS) structure. Areas with CSS were characterized by large, uniform SAV patches. In contrast, areas with FSS were characterized by a higher density of smaller, more complex SAV patches. Furthermore, the areas with CSS and FSS structures clustered in zones of the bay with distinct salinity properties. The areas with CSS structures were mostly located in zones characterized by high and stable salinity. However, the areas with FSS concentrated in zones that are influenced by freshwater discharges from canals and with low and variable salinity. The responses of fish diversity metrics were not constrained to the scale at which the greatest spatial heterogeneity of SAV seascape structures was observed (i.e., the seascape composition and configuration within 200 m from shore), but was related to SAV seascape characteristics across different scales. The majority of the variability of the fish diversity metrics in the mangrove shoreline was explained by SAV seascape structures within the smaller scales (i.e., 100-400 m from shore), and SAV seascape structures that represented the level of fragmentation and/or the percent of suitable habitat. Different conceptual models were proposed to illustrate and understand the ecological dynamics behind the relationship between the diversity of the mangrove fish community and the structure of the adjacent SAV seascape. In general, the diversity and abundance of fishes is influenced by the type and level of fragmentation of the SAV seascape, which, in turn, influence the proportion of the seascape used for foraging and refuge by fish. In conclusion, this research quantified how the release of large pulses of freshwater into near-shore habitats of coastal lagoons can influence the seascape structure of SAV communities. Namely, freshwater inputs produce fragmentation in otherwise fairly homogeneous SAV meadows. The outcome of this research highlights the importance of seascape characteristics as indicators of ecosystem-level modifications and alterations affecting the spatial distribution, assemblage, and diversity of marine nearshore habitats in coastal regions heavily influenced by human activities. In addition, the results illustrated the cascading effects and synergistic influences of near-shore habitat spatial assemblages on the composition and diversity of estuarine fish communities. Lastly, and very importantly, the relationships established in this project provide quantitative and qualitative information on patterns of species-habitat associations needed for the improved synergistic management and protection of coastal habitats and fisheries resources.
83

Estimation of Biomass and Carbon Stock in Para rubber Plantation in East Thailand Using Object-based Classification from THAICHOTE Satellite Data / Évaluation de la biomasse et du stockage de carbone dans les plantations de Para rubber dans l'Est de la Thaïlande par l'utilisation de l'objet en fonction de la classification des données du satellite THAICHOTE

Charoenjit, Kitsanai 18 June 2015 (has links)
Cette étude a été effectuée pour améliorer l'efficacité des mesures de stockage de carbone par des techniques de télédétection dans les plantations de Para rubber (Hevea brasiliensis) en Thaïlande. Les estimations des méthodes actuelles de stockage de carbone s’opèrent à l’aide de la classification classique basée sur le système des pixels basée sur des images de moyenne résolution et produit donc des résultats d’une grande incertitude. En revanche, dans cette étude, la méthode utilisée est basée sur des images de très haute résolution provenant du satellite THAICHOTE, associés à des mesures sur le terrain, dans le bassin de Mae num Prasae. L’utilisation de l'objet en fonction des classifications, les plantations cartographiées, leur âge et leur circonférence ont été estimées à partir d'un modèle paramétrique dérivé de données spectrales, de texture et 3D. L'étude propose une information de texture plus utile que l'information spectrale pour capturer l’architecture des arbres du couvert et donc l'âge de la canopée. Un spectrale de Global Environment Monitoring (GEMI) et quatre texturales de Homogeneity, Dissimilarity, Contrast et Variance ont été utilisées dans l'ajustement du modèle (régression R2 = 0,87) pour estimer la circonférence et l'âge des arbres tandis que le Canopy Height Model (CHM) de 3D n’était pas autorisée pour construire l'information de classement d'images. Environ 154 km2 des 232 km2 de la zone étudiée sont couverts par des plantations. La quantité totale de la biomasse et des stocks de carbone s’élève à 2,23 mégatonnes et 0,99 mégatonnes C, respectivement avec une incertitude de 11%. En 2011, la superficie totale séquestrée était de 121 tCO2 par des plantations. / This study explored to the improve efficiency of measurements of carbon stock by remote sensing techniques on Para rubber (Hevea brasiliensis) plantations in East Thailand. Current methods of carbon stock estimations use classical pixel based classification on middle-resolution images and thus produce results with a large uncertainty. In this study, the method use very high resolution images from the THAICHOTE satellite, associated to field measurements to estimates the carbon stock and its evolution in the Mae num Prasae watershed. Using object based classifications, the plantations have been mapped and their age and girth have been estimated from a parametric model derived from spectral, textural, 3D information and field data. The results of this study show that these data can be used to map Para rubber plantation and distinguish age classes of trees in the plantations. The study propose that textural information is more useful than spectral information to capture tree canopy architecture and thus the age of the canopy. One spectral of Global Environment Monitoring (GEMI) and four textural information of Homogeneity, Dissimilarity, Contrast and Variance were used in the fit model (multiple linear regression R2=0.87) for estimating the Para rubber tree girth and age while the 3D information (canopy height model: CHM) was not appropriated to build the image classification information. Around 154 km2 of the 232 km2 of the studied area are covered by Para rubber plantations. The total amount of biomass and carbon stocks are 2.23 Megatons and 0.99 Megatons C respectively with uncertainty of 11%. In 2011, the total area sequestered 121 tCO2 by Para rubber plantations.
84

High Resolution Satellite Images and LiDAR Data for Small-Area Building Extraction and Population Estimation

Ramesh, Sathya 12 1900 (has links)
Population estimation in inter-censual years has many important applications. In this research, high-resolution pan-sharpened IKONOS image, LiDAR data, and parcel data are used to estimate small-area population in the eastern part of the city of Denton, Texas. Residential buildings are extracted through object-based classification techniques supported by shape indices and spectral signatures. Three population indicators -building count, building volume and building area at block level are derived using spatial joining and zonal statistics in GIS. Linear regression and geographically weighted regression (GWR) models generated using the three variables and the census data are used to estimate population at the census block level. The maximum total estimation accuracy that can be attained by the models is 94.21%. Accuracy assessments suggest that the GWR models outperformed linear regression models due to their better handling of spatial heterogeneity. Models generated from building volume and area gave better results. The models have lower accuracy in both densely populated census blocks and sparsely populated census blocks, which could be partly attributed to the lower accuracy of the LiDAR data used.
85

Caracterização do uso da terra em periferias urbanas utilizando geotecnologias: bacia do Reservatório Guarapiranga / Land use characterization in urban peripheries using geo-technologies: Guarapiranga Reservoir basin

Aline Salim 02 September 2013 (has links)
O estudo das cidades requer um olhar amplo, capaz de identificar e relacionar os inúmeros processos que atuam na produção do espaço urbano. Geotecnologias comumente são utilizadas para adquirir informação detalhada da cobertura da terra do espaço urbano. Neste contexto, o objetivo desta pesquisa é a proposição de metodologia para geração de informações da ocupação urbana nas periferias, definindo procedimentos para análise urbana que gere informações sobre as características da ocupação urbana, a partir de imagens de satélite de alta resolução espacial. Para tanto, foi escolhida como área de estudo o distrito do Jardim São Luís compreendido na bacia do reservatório Guarapiranga, manancial que fornece água para a Região Metropolitana de São Paulo (RMSP) e cuja bacia é área de proteção e recuperação de mananciais, de acordo com a legislação estadual. Foram realizadas discussões de como se organiza o espaço urbano e dos processos que refletiram na ocupação urbana da periferia da RMSP. A metodologia desenvolvida nesta pesquisa articulou o uso de técnicas de Sensoriamento Remoto e Sistemas de Informação Geográfica com dados socioeconômicos do censo demográfico. Os resultados foram apresentados e discutidos e a metodologia proposta demonstrou-se promissora para ser aplicada na atualização de informação do espaço urbano para subsidiar o planejamento urbano e a gestão territorial e consequentemente, para a melhoria da qualidade de vida da população. / Studies from cities require a wide look to identify the amount of processes occurring in the production of the urban space. Geo-technologies are commonly used to acquire detailed information of land cover from the urban space. In this context, the objective of this study is to propose methodology for the generation of information from the occupation at the urban peripheries, defining procedures for the analysis of urban areas, to obtain information of the characteristics of this occupation, from high resolution satellite images. The area under study was the district Jardim São Luis, located at the Guarapiranga Reservoir basin, an important water supplier for the São Paulo Metropolitan Region (RMSP), an area of environmental protection and recuperation, according to State legislation. Discussions were made on how the urban space is organized and on the processes of urban occupation in the periphery of RMSP. The methodology developed in this study used remote sensing and GIS techniques and socio-economic data from the last demographic census. The results were presented and the methodology proposed is very promising to be used to update information of the urban space and land management and consequently to improve the quality of life from the population.
86

Understanding the Antecedents of Perceived Authenticity to Predict Cultural Tourists’ Behavioral Intention: The Case of Cambodia’s Angkor Wat

Hong, Ellen 10 September 2021 (has links)
No description available.
87

Extrakce krajinných prvků z dat dálkového průzkumu / Extraction Landscape Elements from Remote Sensing Data

Martinová, Olga January 2013 (has links)
In this thesis, an approach to automatically derive information about land cover from the remotely sensed data is presented. The data interpretation was done with classification process and performed in software eCognition Developer. The Object-based image analysis, which assignes the classes - for example land cover types, to clusters of pixels (=objects), was used. For the classification, products of two different data sources were combined - the orthophotos generated from aerial imagery and Normalized Digital surface model derived from LiDAR data. Five types of landscape elements were identified and classified.
88

Assessing, monitoring and mapping forest resources in the Blue Nile Region of Sudan using an object-based image analysis approach

Mahmoud El-Abbas Mustafa, Mustafa 28 January 2015 (has links)
Following the hierarchical nature of forest resource management, the present work focuses on the natural forest cover at various abstraction levels of details, i.e. categorical land use/land cover (LU/LC) level and a continuous empirical estimation of local operational level. As no single sensor presently covers absolutely all the requirements of the entire levels of forest resource assessment, multisource imagery (i.e. RapidEye, TERRA ASTER and LANDSAT TM), in addition to other data and knowledge have been examined. To deal with this structure, an object-based image analysis (OBIA) approach has been assessed in the destabilized Blue Nile region of Sudan as a potential solution to gather the required information for future forest planning and decision making. Moreover, the spatial heterogeneity as well as the rapid changes observed in the region motivates the inspection for more efficient, flexible and accurate methods to update the desired information. An OBIA approach has been proposed as an alternative analysis framework that can mitigate the deficiency associated with the pixel-based approach. In this sense, the study examines the most popular pixel-based maximum likelihood classifier, as an example of the behavior of spectral classifier toward respective data and regional specifics. In contrast, the OBIA approach analyzes remotely sensed data by incorporating expert analyst knowledge and complimentary ancillary data in a way that somehow simulates human intelligence for image interpretation based on the real-world representation of the features. As the segment is the basic processing unit, various combinations of segmentation criteria were tested to separate similar spectral values into groups of relatively homogeneous pixels. At the categorical subtraction level, rules were developed and optimum features were extracted for each particular class. Two methods were allocated (i.e. Rule Based (RB) and Nearest Neighbour (NN) Classifier) to assign segmented objects to their corresponding classes. Moreover, the study attempts to answer the questions whether OBIA is inherently more precise at fine spatial resolution than at coarser resolution, and how both pixel-based and OBIA approaches can be compared regarding relative accuracy in function of spatial resolution. As anticipated, this work emphasizes that the OBIA approach is can be proposed as an advanced solution particulary for high resolution imagery, since the accuracies were improved at the different scales applied compare with those of pixel-based approach. Meanwhile, the results achieved by the two approaches are consistently high at a finer RapidEye spatial resolution, and much significantly enhanced with OBIA. Since the change in LU/LC is rapid and the region is heterogeneous as well as the data vary regarding the date of acquisition and data source, this motivated the implementation of post-classification change detection rather than radiometric transformation methods. Based on thematic LU/LC maps, series of optimized algorithms have been developed to depict the dynamics in LU/LC entities. Therefore, detailed change “from-to” information classes as well as changes statistics were produced. Furthermore, the produced change maps were assessed, which reveals that the accuracy of the change maps is consistently high. Aggregated to the community-level, social survey of household data provides a comprehensive perspective additionally to EO data. The predetermined hot spots of degraded and successfully recovered areas were investigated. Thus, the study utilized a well-designed questionnaire to address the factors affecting land-cover dynamics and the possible solutions based on local community's perception. At the operational structural forest stand level, the rationale for incorporating these analyses are to offer a semi-automatic OBIA metrics estimates from which forest attribute is acquired through automated segmentation algorithms at the level of delineated tree crowns or clusters of crowns. Correlation and regression analyses were applied to identify the relations between a wide range of spectral and textural metrics and the field derived forest attributes. The acquired results from the OBIA framework reveal strong relationships and precise estimates. Furthermore, the best fitted models were cross-validated with an independent set of field samples, which revealed a high degree of precision. An important question is how the spatial resolution and spectral range used affect the quality of the developed model this was also discussed based on the different sensors examined. To conclude, the study reveals that the OBIA has proven capability as an efficient and accurate approach for gaining knowledge about the land features, whether at the operational forest structural attributes or categorical LU/LC level. Moreover, the methodological framework exhibits a potential solution to attain precise facts and figures about the change dynamics and its driving forces. / Da das Waldressourcenmanagement hierarchisch strukturiert ist, beschäftigt sich die vorliegende Arbeit mit der natürlichen Waldbedeckung auf verschiedenen Abstraktionsebenen, das heißt insbesondere mit der Ebene der kategorischen Landnutzung / Landbedeckung (LU/LC) sowie mit der kontinuierlichen empirischen Abschätzung auf lokaler operativer Ebene. Da zurzeit kein Sensor die Anforderungen aller Ebenen der Bewertung von Waldressourcen und von Multisource-Bildmaterialien (d.h. RapidEye, TERRA ASTER und LANDSAT TM) erfüllen kann, wurden zusätzlich andere Formen von Daten und Wissen untersucht und in die Arbeit mit eingebracht. Es wurde eine objekt-basierte Bildanalyse (OBIA) in einer destabilisierten Region des Blauen Nils im Sudan eingesetzt, um nach möglichen Lösungen zu suchen, erforderliche Informationen für die zukünftigen Waldplanung und die Entscheidungsfindung zu sammeln. Außerdem wurden die räumliche Heterogenität, sowie die sehr schnellen Änderungen in der Region untersucht. Dies motiviert nach effizienteren, flexibleren und genaueren Methoden zu suchen, um die gewünschten aktuellen Informationen zu erhalten. Das Konzept von OBIA wurde als Substitution-Analyse-Rahmen vorgeschlagen, um die Mängel vom früheren pixel-basierten Konzept abzumildern. In diesem Sinne untersucht die Studie die beliebtesten Maximum-Likelihood-Klassifikatoren des pixel-basierten Konzeptes als Beispiel für das Verhalten der spektralen Klassifikatoren in dem jeweiligen Datenbereich und der Region. Im Gegensatz dazu analysiert OBIA Fernerkundungsdaten durch den Einbau von Wissen des Analytikers sowie kostenlose Zusatzdaten in einer Art und Weise, die menschliche Intelligenz für die Bildinterpretation als eine reale Darstellung der Funktion simuliert. Als ein Segment einer Basisverarbeitungseinheit wurden verschiedene Kombinationen von Segmentierungskriterien getestet um ähnliche spektrale Werte in Gruppen von relativ homogenen Pixeln zu trennen. An der kategorische Subtraktionsebene wurden Regeln entwickelt und optimale Eigenschaften für jede besondere Klasse extrahiert. Zwei Verfahren (Rule Based (RB) und Nearest Neighbour (NN) Classifier) wurden zugeteilt um die segmentierten Objekte der entsprechenden Klasse zuzuweisen. Außerdem versucht die Studie die Fragen zu beantworten, ob OBIA in feiner räumlicher Auflösung grundsätzlich genauer ist als eine gröbere Auflösung, und wie beide, das pixel-basierte und das OBIA Konzept sich in einer relativen Genauigkeit als eine Funktion der räumlichen Auflösung vergleichen lassen. Diese Arbeit zeigt insbesondere, dass das OBIA Konzept eine fortschrittliche Lösung für die Bildanalyse ist, da die Genauigkeiten - an den verschiedenen Skalen angewandt - im Vergleich mit denen der Pixel-basierten Konzept verbessert wurden. Unterdessen waren die berichteten Ergebnisse der feineren räumlichen Auflösung nicht nur für die beiden Ansätze konsequent hoch, sondern durch das OBIA Konzept deutlich verbessert. Die schnellen Veränderungen und die Heterogenität der Region sowie die unterschiedliche Datenherkunft haben dazu geführt, dass die Umsetzung von Post-Klassifizierungs- Änderungserkennung besser geeignet ist als radiometrische Transformationsmethoden. Basierend auf thematische LU/LC Karten wurden Serien von optimierten Algorithmen entwickelt, um die Dynamik in LU/LC Einheiten darzustellen. Deshalb wurden für Detailänderung "von-bis"-Informationsklassen sowie Veränderungsstatistiken erstellt. Ferner wurden die erzeugten Änderungskarten bewertet, was zeigte, dass die Genauigkeit der Änderungskarten konstant hoch ist. Aggregiert auf die Gemeinde-Ebene bieten Sozialerhebungen der Haushaltsdaten eine umfassende zusätzliche Sichtweise auf die Fernerkundungsdaten. Die vorher festgelegten degradierten und erfolgreich wiederhergestellten Hot Spots wurden untersucht. Die Studie verwendet einen gut gestalteten Fragebogen um Faktoren die die Dynamik der Änderung der Landbedeckung und mögliche Lösungen, die auf der Wahrnehmung der Gemeinden basieren, anzusprechen. Auf der Ebene des operativen strukturellen Waldbestandes wird die Begründung für die Einbeziehung dieser Analysen angegeben um semi-automatische OBIA Metriken zu schätzen, die aus dem Wald-Attribut durch automatisierte Segmentierungsalgorithmen in den Baumkronen abgegrenzt oder Cluster von Kronen Ebenen erworben wird. Korrelations- und Regressionsanalysen wurden angewandt, um die Beziehungen zwischen einer Vielzahl von spektralen und strukturellen Metriken und den aus den Untersuchungsgebieten abgeleiteten Waldattributen zu identifizieren. Die Ergebnisse des OBIA Rahmens zeigen starke Beziehungen und präzise Schätzungen. Die besten Modelle waren mit einem unabhängigen Satz von kreuz-validierten Feldproben ausgestattet, welche hohe Genauigkeiten ergaben. Eine wichtige Frage ist, wie die räumliche Auflösung und die verwendete Bandbreite die Qualität der entwickelten Modelle auch auf der Grundlage der verschiedenen untersuchten Sensoren beeinflussen. Schließlich zeigt die Studie, dass OBIA in der Lage ist, als ein effizienter und genauer Ansatz Kenntnisse über die Landfunktionen zu erlangen, sei es bei operativen Attributen der Waldstruktur oder auch auf der kategorischen LU/LC Ebene. Außerdem zeigt der methodischen Rahmen eine mögliche Lösung um präzise Fakten und Zahlen über die Veränderungsdynamik und ihre Antriebskräfte zu ermitteln.
89

Hodnocení změn pokryvu Země pomocí objektových detekcí / Evaluation of Land Cover Changes Using the Object Detections

Skokanová, Eliška January 2011 (has links)
The aim of the project is to perform object based change detection of land cover in specific areas of Czech republic. Landsat 2000 and Spot 2006 satellite images are used as input data. The method used for evaluation of changes is Multivariate Alteration Detection unsupervised method which is based on statistical procedures and is available from e-Cognition software. The results of detection are compared with Corine Land Cover changes database to evaluate degree of parity on detected areas. Different mapping unit is used to be able to detect smaller changes than Corine database. First part of the work is review of literature sources aimed on processing of satellite images, description of the spectral behavior of landscape objects, origins of Corine Land Cover database and principle of change detection using MAD. Second part deals with data adjustment, change detection process and comparison of reached results with Corine. Keywords: object based change detection, satellite images, Corine Land Cover, mapping unit of changes, Multivariate Alteration Detection, e-Cognition
90

Kvalitetssäkring av objektsbaserade IFC-filer för mängdavtagningar och kostnadskalkyler : En fallstudie av levererade konstruktionsmodeller, vid Tyréns AB Stockholm / Quality assurance of object-based IFC-files for quantity takeoff and cost estimating : A case study of delivered construction models, at Tyréns AB Stockholm

Gustavsson, Sam, Johansson, Filip January 2013 (has links)
Att utföra kostnadskalkyler och mängdavtagningar utifrån objektbaserade 3D-modeller har visat sig vara problematiskt då modellerna inte uppfyller de förväntade kraven på informationsnivå. De bristande modellerna leder till en större osäkerhet då kalkylatorn skall upprätta kostnadskalkyler, vilket utgör bakgrunden till de frågeställningar som rapporten utgörs av. Projektet Biomedicum, som skall bli det toppmoderna laboratoriet åt Karolinska Institutet bedrivs som ett fullskaligt BIM-projekt, där de objektbaserade 3D-modellerna utgör underlaget för bland annat kostnadskalkyler i systemhandlingsskedet. Kalkylatorn i projektet, har uttryckt ett missnöje gällande kvaliteten i modellerna, och menar på att det finns stora brister som leder till att risken för att osäkra kalkyler upprättas ökar. Denna rapport kommer således att se över hur det är möjligt att kvalitetssäkra en objektbaserad 3D-modell i IFC-format i programvaran Solibri Model Checker, utifrån de projektspecifika kraven som råder i projektet. Rapporten utgörs av en fallstudie och en litteraturstudie, och till viss del även av intervjuer. I fallstudien undersöks det om Solibri Model Checker är kapabel till att kontrollera modellerna utifrån de projektspecifika krav som råder i projektet, samt att analysera resultatet av kontrollerna som har utförts. Intervjuerna i sin tur har legat till grund för ett antal problem som har ansetts vara relevanta för rapporten. Problem som kan härledas till juridiska svårigheter, avsaknad av en gemensam branschstandard, meningsskiljaktigheter kring innehållet i en objektbaserad 3D-modell etc.  I fallstudien har det visat sig att 3D-modellerna är bristande ur kalkylsynpunkt. Detta leder till svårigheter och osäkerheter då Skanska upprättar kalkylerna. Anledningarna till detta är flera. Det handlar bland annat om att konstruktören använder sig av en modelleringsteknik som inte är anpassad för kalkylering, men även att det inte finns tydliga riktlinjer om vilken information som bör finnas i objekten i systemhandlingsskedet, vilket har framgått under intervjuerna. Det har även framgått under intervjuerna, att ett avgörande problem som kan anknytas till att modellerna är av bristande kvalitet ur kalkylsynpunkt, är på grund av att det inte har ställts krav tillräckligt tidigt i processen. Vad som är viktigt för att få en fungerande process där de objektbaserade 3D-modellerna skall användas för mängdavtagningar och kostnadskalkyler, är att i ett tidigt skede fastslå vilken information som behövs i objekten för att trovärdiga kalkyler skall vara möjliga att upprätta. Vikten av att det finns en tydlig IT-handledning är även stor, då det är handledningen som ligger till underlag om vilken information som skall finnas med i modellerna. / To perform quantity takeoffs and cost estimates based on 3D models is problematic, if the models do not meet the expected demands of information. The weaknesses of the models leads to uncertainty when the calculator will establish cost estimates, which forms the background to the issues that the thesis constitutes. The project Biomedicum is conducted as a full-fledged BIM project, where the object based 3D models are the basis for cost estimates in the system phase. The calculator in the project has expressed dissatisfaction regarding the quality of the models, and believes that there are major flaws that lead to the risk of uncertain calculations increasing. Of this reason, this thesis will analyze the possibilities about ensuring the quality of an object based 3D model in IFC format, by using the software Solibri Model Checker. This thesis consists of a literature review, interviews and a case study. The case study examines whether Solibri Model Checker is capable of checking the models based on the project specific requirements, and to analyze the results of the checks that have carried out in the case study. The interviews have been the basis for the number of problems that have been considered relevant for the thesis. Problems that can be traced to legal difficulties, lack of a common set requirements, disagreements about the content of an object based 3D model etc. The case study has shown that the 3D models are inadequate to perform cost estimates, which leads to difficulties and uncertainties in the calculation process. There are several reasons for this. The designers of the project have used wrong modeling technique for quantity takeoff and cost estimating. But also that there are no clear guidelines as to what information should be included in the items in the document stage system, which has emerged during the interviews. It has also emerged during the interviews that crucial problems that may be linked to the models are of poor quality, because it has not been required early enough in the process. What is important to get a working process in which the object-based 3D models to be used for quantity takeoffs and cost estimates, is that in the early stages determine what information is needed in the objects to credible estimates will be possible to establish. The importance of a clear IT manual is also great, as it is the manual who serves as the basis of the information to be included in the models.

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