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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.
131

Data mining of geospatial data: combining visual and automatic methods

Demšar, Urška January 2006 (has links)
Most of the largest databases currently available have a strong geospatial component and contain potentially useful information which might be of value. The discipline concerned with extracting this information and knowledge is data mining. Knowledge discovery is performed by applying automatic algorithms which recognise patterns in the data. Classical data mining algorithms assume that data are independently generated and identically distributed. Geospatial data are multidimensional, spatially autocorrelated and heterogeneous. These properties make classical data mining algorithms inappropriate for geospatial data, as their basic assumptions cease to be valid. Extracting knowledge from geospatial data therefore requires special approaches. One way to do that is to use visual data mining, where the data is presented in visual form for a human to perform the pattern recognition. When visual mining is applied to geospatial data, it is part of the discipline called exploratory geovisualisation. Both automatic and visual data mining have their respective advantages. Computers can treat large amounts of data much faster than humans, while humans are able to recognise objects and visually explore data much more effectively than computers. A combination of visual and automatic data mining draws together human cognitive skills and computer efficiency and permits faster and more efficient knowledge discovery. This thesis investigates if a combination of visual and automatic data mining is useful for exploration of geospatial data. Three case studies illustrate three different combinations of methods. Hierarchical clustering is combined with visual data mining for exploration of geographical metadata in the first case study. The second case study presents an attempt to explore an environmental dataset by a combination of visual mining and a Self-Organising Map. Spatial pre-processing and visual data mining methods were used in the third case study for emergency response data. Contemporary system design methods involve user participation at all stages. These methods originated in the field of Human-Computer Interaction, but have been adapted for the geovisualisation issues related to spatial problem solving. Attention to user-centred design was present in all three case studies, but the principles were fully followed only for the third case study, where a usability assessment was performed using a combination of a formal evaluation and exploratory usability. / QC 20110118
132

Poverty Mapping With Geographic Information Systems: A Case Study In Kecioren District, Ankara

Kalaycioglu, Mehmet 01 December 2006 (has links) (PDF)
In the world today and in Turkey, poverty and its alleviation has become an important issue. As a result, detailed studies for the identification of poverty need to be done. In the recent years, the spatial aspect of the multidimensional character of poverty is gaining significance. For this purpose, in this thesis, spatial aspects of poverty are tried to be analysed using Geographic Information Systems (GIS) in the case of Ke&ccedil / i&ouml / ren District in Ankara. Firstly, a digital map of the spatial distribution of the urban poor living in Ke&ccedil / i&ouml / ren is made and linked to the database to analyse the spatial distribution. The poverty database used in this study is based on the data collected by the Social Assistance and Solidarity Foundation in the district. It includes state of poverty and some sociodemographic characteristics of the households who applied for social assistance. The analyses with respect to the methodology of this study aims at finding the common characteristics of poor settlements and the areas/households which are the poorest of the poor in Ke&ccedil / i&ouml / ren. The maps obtained as a result of spatial data analysis indicate the dense living areas of the poor, clusters of poor households, neighbourhood level poverty analysis and poor areas within neighbourhoods. There are also additional analyses which compare the characteristics of the geographical distribution of the poor with other aspects, such as land values, roads and building conditions. Such a study can be helpful to re-allocate the poverty alleviation efforts more efficiently by determining priority areas.
133

A Methodology Of Swarm Intelligence Application In Clustering Based On Neighborhood Construction

Inkaya, Tulin 01 May 2011 (has links) (PDF)
In this dissertation, we consider the clustering problem in data sets with unknown number of clusters having arbitrary shapes, intracluster and intercluster density variations. We introduce a clustering methodology which is composed of three methods that ensures extraction of local density and connectivity properties, data set reduction, and clustering. The first method constructs a unique neighborhood for each data point using the connectivity and density relations among the points based upon the graph theoretical concepts, mainly Gabriel Graphs. Neighborhoods subsequently connected form subclusters (closures) which constitute the skeleton of the clusters. In the second method, the external shape concept in computational geometry is adapted for data set reduction and cluster visualization. This method extracts the external shape of a non-convex n-dimensional data set using Delaunay triangulation. In the third method, we inquire the applicability of Swarm Intelligence to clustering using Ant Colony Optimization (ACO). Ants explore the data set so that the clusters are detected using density break-offs, connectivity and distance information. The proposed ACO-based algorithm uses the outputs of the neighborhood construction (NC) and the external shape formation. In addition, we propose a three-phase clustering algorithm that consists of NC, outlier detection and merging phases. We test the strengths and the weaknesses of the proposed approaches by extensive experimentation with data sets borrowed from literature and generated in a controlled manner. NC is found to be effective for arbitrary shaped clusters, intracluster and intercluster density variations. The external shape formation algorithm achieves significant reductions for convex clusters. The ACO-based and the three-phase clustering algorithms have promising results for the data sets having well-separated clusters.
134

GIS, data mining and wild land fire data within Räddningstjänsten

Sandell, Anna January 2001 (has links)
<p>Geographical information systems (GIS), data mining and wild land fire would theoretically be suitable to use together. However, would data mining in reality bring out any useful information from wild land fire data stored within a GIS? In this report an investigation is done if GIS and data mining are used within Räddningstjänsten today in some municipalities of the former Skaraborg. The investigation shows that neither data mining nor GIS are used within the investigated municipalities. However, there is an interest in using GIS within the organisations in the future but also some kind of analysis tool, for example data mining. To show how GIS and data mining could be used in the future within Räddningstjänsten some examples on this were constructed.</p>
135

Data mining of geospatial data: combining visual and automatic methods

Demšar, Urška January 2006 (has links)
<p>Most of the largest databases currently available have a strong geospatial component and contain potentially useful information which might be of value. The discipline concerned with extracting this information and knowledge is data mining. Knowledge discovery is performed by applying automatic algorithms which recognise patterns in the data.</p><p>Classical data mining algorithms assume that data are independently generated and identically distributed. Geospatial data are multidimensional, spatially autocorrelated and heterogeneous. These properties make classical data mining algorithms inappropriate for geospatial data, as their basic assumptions cease to be valid. Extracting knowledge from geospatial data therefore requires special approaches. One way to do that is to use visual data mining, where the data is presented in visual form for a human to perform the pattern recognition. When visual mining is applied to geospatial data, it is part of the discipline called exploratory geovisualisation.</p><p>Both automatic and visual data mining have their respective advantages. Computers can treat large amounts of data much faster than humans, while humans are able to recognise objects and visually explore data much more effectively than computers. A combination of visual and automatic data mining draws together human cognitive skills and computer efficiency and permits faster and more efficient knowledge discovery.</p><p>This thesis investigates if a combination of visual and automatic data mining is useful for exploration of geospatial data. Three case studies illustrate three different combinations of methods. Hierarchical clustering is combined with visual data mining for exploration of geographical metadata in the first case study. The second case study presents an attempt to explore an environmental dataset by a combination of visual mining and a Self-Organising Map. Spatial pre-processing and visual data mining methods were used in the third case study for emergency response data.</p><p>Contemporary system design methods involve user participation at all stages. These methods originated in the field of Human-Computer Interaction, but have been adapted for the geovisualisation issues related to spatial problem solving. Attention to user-centred design was present in all three case studies, but the principles were fully followed only for the third case study, where a usability assessment was performed using a combination of a formal evaluation and exploratory usability.</p>
136

Developing baseline data for monitoring and evaluation of land registration implementation in Rwanda : a case study of Gasabo district.

Rurangwa, Eugène. January 2007 (has links)
Various literature suggest that securing access to land and guaranteeing land tenure security is essential for diverse land-based livelihoods and remains a prerequisite for sustainable agriculture, economic growth and poverty reduction. Secure land tenure is recognized as a key element to meeting the MDG target 11 to achieve significant improvement in the lives of 100 million slums dwellers by 2020. In the case of Rwanda, land tenure reform involves changes in land tenure systems from traditional and customary arrangements to more simple, modern and streamlined land tenure mechanisms guided by a core land registration system which is affordable, efficient and participatory. This development towards change in land registration patterns requires strong instruments for monitoring and evaluation and impact assessment of land registration implementation. The main purpose of this research is to develop key indicators to be used as baseline monitoring and evaluation instruments for land registration implementation in Rwanda, the shortage of time having limited the case study to one, but important District of Rwanda: Gasabo. The conceptual argument follows the logic of thinking that, when land tenure, symbolized by different values is supported by formal or legal land registration procedures, it gives it a dimension of power, insurance, guarantee and security that can be symbolized by different indicators measurable as variables. Seven key indicators were identified. To test the defined baseline indicators for validity, data was obtained from a sample of 150 respondents using a cluster sampling technique and structured interviews. The findings demonstrate the defined indicators could be measured and the quality of measurement (validity) established from statistical behavior of the variables. The results have shown that none of sampled households has a land title, this effect being recognized as a major hindrance to tenure security and to fruitful investment in land. Only those few who had other kinds of documents confirming rights to land, although of lesser weight, were eligible to a loan from a bank. The results have shown that the beneficiaries of bank loans have improved their income by being involved in land transactions and by acquiring a new land as well as buying domestic animals. The results also show that these interactions have brought a significant improvement in land productivity and consequently, raised income. Although household date showed low rate of land disputes, secondary data at district level showed significantly higher rates of occurrence and very low rates of dispute resolution. It is generally observed that land disputes could be avoided or solved if sufficient operational, legal and institutional instruments for disputes resolution and land registration are in place. / Thesis (M.Env.Dev.) - University of KwaZulu-Natal, Pietermaritzburg, 2007.
137

Assessment Of Social Vulnerability Using Geographic Information Systems: Pendik, Istanbul Case Study

Gungor Haki, Zeynep 01 December 2003 (has links) (PDF)
Natural hazards are the reality of today&amp / #8217 / s world, which considerably affect people&amp / #8217 / s living conditions. As they cannot be prevented, the basic precautions should be taken before the occurrence to protect people. At this point, the preparedness for any threat is really important, which does decrease destructive effects of the hazard for communities and shorten recovery interventions. In terms of preparedness, identification of vulnerable people in the community gives an important contribution for better planning in disaster management. In this respect, this thesis aims to develop a methodology in order to define vulnerable groups in terms of their social conditions for any possible hazard, with Geographic Information Systems (GIS) technology. Moreover, the thesis aims to find out an interrelation between hazards and vulnerability, to build awareness about identification of socially vulnerable groups in the pre- and post-disaster planning. A case study area is selected in earthquake-prone Pendik, Istanbul, in order to find the contribution of the assessment. A study is carried out to describe social vulnerability levels in the study area using GIS. Criterion standardization, weighting and combining are accomplished by multi criteria evaluation methods. These calculations are supported with five explorative spatial data analyses to understand global trends and spatial interactions of the study data. The objectivity of the assessment and the complicated structure of the study data are also discussed. The main outcomes of the methodology and its applications in the case study area show that, the southeast part of Pendik is socially vulnerable to any possible hazard.
138

Using Geographic Information Systems In Analysing The Pattern Of Crime Incidents And The Relationship Between Landuse And Incidents

Akpinar, Ebru 01 March 2003 (has links) (PDF)
The location where crime events occur is an important factor in the analysis of crime. It is not only important where a crime incident takes place but also the characteristics of those places and the environment in which incident occurs. Thus, examination of spatial data such as street networks, parcel information, school locations, commercial and residential zoning, is imperative for effective crime analysis, crime prevention and police activities. Using variables, relating to five incident types as burglary, auto, pick pocket, usurp and murder, which are recorded by the police in 2003 and including the information of where and when crime incident occurs, this thesis attempts to analyze the high-incident areas and the relationship between these incidents and land uses for two important police precincts of &Ccedil / ankaya district of Ankara / Centre of &Ccedil / ankaya Police Station Zone and Bah&ccedil / elievler Police Station Zone. The aim of the study is to improve a methodology for the determination of the effects of land use variables on the distribution of crime incidents. The study applies some methods related to the spatial data analysis which can be also integrated with Geographic Information Systems. In the study, in order to identify the current pattern of the incidents, kernel estimation method is found as the best method while Nearest Neighbor Hierarchical Clustering method is preferred to analyze what land uses are prone to incidents. In order to determine the properties of the relationships between land use and incidents correlation calculations are performed. At the end, the potential crime incident areas are determined by referring these relationships with GIS functions.
139

A User-Oriented Map Design in the SDI Environment / Nutzerorientierte Kartengestaltung im Rahmen von Geodateninfrastrukturen – am Beispiel einer Europäischen Referenzkarte mittleren Maßstabs

Hopfstock, Anja 27 September 2011 (has links) (PDF)
The ever increasing demand of our information society for reliable Geographic Information (GI) is the moving power for the development and maintenance of Spatial Data Infrastructures (SDI). Consequently, an SDI works to full benefit of its users if the SDI data collection is accessible and can be efficiently used by all users in spatial problem solving and decision-making. Current development and use of SDI focuses on handling geospatial data entirely by means of information technology. Thereby, low awareness seems to be paid to a user-friendly and understandable presentation of geospatial data. Based on the understanding that GI is the result of human geospatial information processing, it is argued that cartography is essential in the SDI context in order to achieve the objectives of SDI. Specifically, the thesis aimed at exploring the concept of user-oriented map design in relation to SDI and elaborating a methodology for creating effective cartographic representations for SDI relevant user types. First of all, the SDI concept, its objectives and principles are explored using the example of the current European SDI initiatives as to the human aspect of an SDI. Secondly, in order to determine the role and task of cartography in the SDI context, the conceptual framework of contemporary cartography is reviewed to provide the theoretical and technological framework for a user-oriented map design. Given this, the SDI environment is assessed in relation to cartography with respect to the services providing access to the SDI data collection. Further, an SDI map production framework is elaborated utilising Spiess’ concept of the graphic filter as a model for the transformation of SDI data into useful cartographic representations. Besides, the map design strategy by Grünreich provides the starting point for developing the process of map production. The main tasks are detailed and justified taking into consideration the semiotic-cognitive and action-related concepts underpinning contemporary cartography. The applied research encompasses a case study which is performed to implement and, thus, evaluate the proposed methodology. It starts from a use case scenario where an international spatial planning team requires getting familiar with the overall geographic characteristics of a European cross-border area. Following the process steps of user-oriented map design in the SDI environment, a map design specification is elaborated and implemented under real world conditions. The elaborated methodology for creating user-friendly and understandable cartographic representations of geospatial data in the SDI environment is based on theoretical and technological foundation of contemporary cartography. Map design in the SDI context, first of all, means to establish a graphic filter that determines the parameters and rules of the cartographic transformation process to be applied. As both an applied art and engineering the design of the graphic filter is a creative process developing a map design solution which enables SDI users to easily produce their map. It requires on the one hand an understanding of map use, map user and map use situation, and on the other hand insight into the data used as the source. The case study proves that the elaborated methodology is practicable and functional. Cartographic reverse engineering provides a systematic and pragmatic approach to the cartographic design task. This way, map design solutions can be built upon existing cartographic experience and common traditions as suggested by the INSPIRE recommendation for portrayal. The resulting design solution constitutes a prototype of a European Reference Map at medium scale built upon existing cartographic experience and common traditions. A user-friendly, understandable and comparable presentation of geospatial data in Europe would support the human and institutional potential for cross-border cooperation and collaboration. Besides that, the test implementation shows that tools are available which make it technically feasible and viable to produce a map from geospatial data in the SDI data collection. The research project raises awareness to the human aspect of SDI inherit in its objective to support end users to derive GI and knowledge from the geospatial data gathered in the SDI data collection. The role and task of cartography in the SDI context is to contribute to the initiation, creation, and maintenance of portrayal services to facilitate a comprehensive access to the underlying geospatial data by means of a user-friendly and understandable graphic interface. For cartography to take effect in the SDI development and use, cartographic design knowledge has to be made explicit and operational. It is the responsibility of cartographic professionals to prepare the map design. The wide range of map use contexts requires a great flexibility of design variants depending on the dimension of human-map interaction. Therefore, the design of the maps needs to be user-driven to enable an efficient map use in the user’s task. Besides their function as a graphic interface, maps facilitate a common understanding of the depicted geographic features and phenomena when sharing GI between SDI users. In other words, map design can be regarded a measure to establish interoperability of geospatial data beyond the technical level. The research work is in the scope of communication cartography, a research domain seeking to deepen the understanding of the role of cartographic expressions when understanding and communication of GI is involved. / Der wachsende Bedarf unserer Wissensgesellschaft an zuverlässigen Informationen über räumliche Strukturen und Sachverhalte ist die treibende Kraft bei Aufbau und Einsatz von Geodateninfrastrukturen (GDI). Eine Geodateninfrastruktur wirkt zum vollen Nutzen der Gesellschaft, wenn die Daten in der GDI zugänglich sind und effektiv für Erkenntnis- und Entscheidungsprozesse genutzt werden können. Die gegenwärtige Entwicklung von GDI setzt auf moderne Informationstechnologien bei der Geodatenverarbeitung. Dabei, wird einer bedarfsgerechten und nutzerfreundlichen Präsentation von Geodaten in ansprechender visueller Form wenig Aufmerksamkeit zuteil. Da Geoinformation erst durch die Interaktion des Nutzers mit den Geodaten entsteht, ist es Aufgabe der Kartographie, bedarfsgerechte Kartendarstellungen zu gestalten und an der Schnittstelle zwischen einer Geodateninfrastruktur und ihren Nutzern bereitzustellen. Ziel der vorliegenden Dissertation ist es, eine Methodik für den Kartenherstellungsprozess in einer GDI-Umgebung zu entwickeln und beispielhaft zu erproben. Zunächst, werden Konzept, Ziele und Prinzipien von Geodateninfrastruktur beispielhaft anhand der Europäischen GDI-Initiativen dargestellt und hinsichtlich des Bedarfs an kartographischen Darstellungen untersucht. Danach wird, ausgehend von der Forderung nach verständlichen und gut interpretierbaren Geoinformationen, die Rolle der Kartographie im GDI-Kontext bestimmt. Dabei werden zunächst Funktion und Aufgaben der Kartographie sowie die tragenden Konzepte und Grundlagen einer nutzerorientierten Kartengestaltung dargelegt. Der Vergleich der bestehenden Geodatenzugangsdienste zur Funktion der Kartographie ergibt eine Lücke, die es zu schließen gilt, um den Nutzeranforderungen gerecht zu werden. Dazu wird der Gesamtprozess für die Herstellung von Karten im GDI-Kontext beschrieben. In diesem Prozess kommt dem Graphikfilter von Spiess (2003) besondere Bedeutung als Modell eines wissensbasierten Systems zur Aufstellung und Umsetzung von kartographischen Gestaltungsregeln zu. Den Ausgangspunkt für die Ausarbeitung der Teilprozesse bieten die von Grünreich (2008) vorgeschlagenen Teilaufgaben der Kartographie im Rahmen der GDI. Mittels eines Anwendungsfalls im Europäischen Kontext wird der vorgeschlagene Gesamtprozess erprobt. Dieses Beispiel geht davon aus, dass eine internationale Planungsgruppe im Zuge der Konzeption einer grenzüberschreitenden Verkehrsverbindung eine anschauliche Beschreibung der Landschaft in Form einer einheitlich gestalteten und flächendeckenden Karte benötigt. Durch Anwendung des kartographischen Reverse Engineering anerkannt gut gestalteter Karten werden die Vorgaben für die Kartengestaltung ermittelt. Einschließlich der Anwendung auf konkrete GDI-Daten wird der zuvor entwickelte Herstellungsprozess ausgeführt und diskutiert. Die entwickelte Methodik für den Kartenherstellungsprozess in der GDI-Umgebung basiert auf den semiotisch-kognitiven und handlungstheoretischen Konzepten der modernen Kartographie. Kartengestaltung im Kontext von Geodateninfrastrukturen bedeutet die Entwicklung eines Graphikfilters, der eine optimale bedarfsgerechte Visualisierung der Geodaten mittels nutzerspezifischer Parameter und Gestaltungsregeln ermöglicht. Wie das Fallbeispiel zeigt, ist es die durch die entwickelte Methodik möglich, brauchbare und nützliche Kartendarstellungen zu gestalten. Die Anwendung des kartographischen Reverse Engineering erlaubt es, Kartendarstellungen zu entwickeln, die - wie von INSPIRE empfohlen - bewährten kartographischen Erfahrungen und allgemeinen Traditionen entsprechen. Das Ergebnis des Anwendungsfalls ist ein Prototyp einer Europäischen Referenzkarte im Maßstab 1: 250,000. Die einheitliche und somit vergleichbare Darstellung über Grenzen hinweg unterstützt das Planungsteam in seiner Arbeit. Die praktische Umsetzung der Karte zeigt zudem, dass funktionsfähige Werkzeuge und Technologien für die regelbasierte Kartenherstellung aus GDI-Daten vorhanden sind. Die Dissertation trägt dazu bei, das Bewusstsein für den menschlichen Aspekt der Nutzung einer Geodateninfrastruktur zu schärfen. Der Beitrag der Kartographie zur Nutzung der Geodaten einer GDI besteht in der Initiierung, Gestaltung und Pflege von Darstellungsdiensten, da die Nutzbarkeit der Geodaten am besten gewährleistet ist, wenn die Gestaltungsmethoden der Kartographie angewendet werden. Dabei liegt es in der Verantwortung der Kartographen, die nutzerseitigen Aspekte dieser graphischen Schnittstelle unter Berücksichtigung der modernen kartographischen Konzepte zu betreuen. Gemäß INSPIRE-Richtlinie werden auf Karten gestützte Informationen bei zahlreichen Tätigkeiten verwendet. Für eine effektive visuelle Informationsverarbeitung durch den Nutzer ist daher eine nutzerorientierte Kartengestaltung in Abhängigkeit von der geplanten Interaktion (z.B. Kommunikation oder Analyse) unerlässlich. Neben der Funktion als Schnittstelle machen kartographische Darstellungen räumliche Strukturen verständlich. Daher ist die Kartenherstellung im GDI-Kontext eine Maßnahme, um Interoperabilität von Geodaten über die technische Ebene hinaus auf menschlicher Ebene zu ermöglichen. Die Relevanz dieser Forschungsarbeit liegt im Bereich der Kommunikationskartographie, die die Effektivität und Verbindlichkeit der Kommunikation über räumliche Strukturen und Sachverhalte zu vertiefen sucht.
140

A spatial decision support system utilizing data from the Gap Analysis Program and a Bayesian Belief Network

Dumas, Jeremiah Percy, January 2005 (has links)
Thesis (M.L.A.) -- Mississippi State University. Department of Landscape Architecture. / Title from title screen. Includes bibliographical references.

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