• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 114
  • 35
  • 13
  • 13
  • 8
  • 4
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 235
  • 235
  • 58
  • 45
  • 42
  • 40
  • 37
  • 37
  • 34
  • 34
  • 31
  • 24
  • 24
  • 22
  • 19
  • 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.
151

A web-based graphical user interface to display spatial data

Fiedeldey, Claudia Alexandra 23 February 2007 (has links)
This dissertation presents the design and implementation of a graphical user interface (GUI) to display spatial data in a web-based environment. The work is a case study for a web-based framework for distributed applications, the Web Computing Skeleton, using a distributed open spatial query mechanism to display the geographic data. The design is based on investigation of geographic information systems (GISs), GUI design and properties of spatial query mechanisms. The purpose ofthe GUI is to integrate information about a geographic area; display, manipulate and query geographic-based spatial data; execute queries about spatial relationships and analyse the attribute data to calculate the shortest routes for emergency response. The GUI is implemented as a Java applet embedded in a web document that communicates with the application server via generic GIS classes that provide a common interface to various GIS data sources used in the spatial query mechanism to access a geographic database. Features that are supported by the distributed open spatial query mechanism include a basic set of spatial selection criteria, spatial selection based on pointing, specification of a query window, description of a map scale and identification of a map legend. The design is based on a formal design process that includes the selection of a conceptual model, identification of task flow, major windows and dialog flow, the definition of fields and detailed window layout and finally the definition of field constraints and defaults. The conceptual model characterises the application and provides a framework for users to learn the system model. This model is conceptualised as a map that the user manipulates directly. Unlike a typical map, which just shows spatial data such as roads, cities, and country borders, the GIS links attribute data like population statistics to the spatial data. This link between the map data and the attribute data makes the GIS a powerful tool to manipulate and display data. To measure the performance of displaying spatial data, two main factors are considered, namely processing speed and display quality. Factors that affect the processing speed include the rate of data transfer from the generic GIS classes, the rate data is downloaded over the network and the speed of execution of the drawing. Two factors that influence the spatial data display quality are pixel distance and bitmap quality. The pixel distance set in the geographic database is represented by two pixels on the display screen, which affects the display quality since the pixel distance is the upper limit for display granularity. This means that setting the pixel distance is a trade-off between the processing speed and the display quality. Bitmaps are raster images that are made up of pixels or cells. To improve the raster image quality, the bitmap resolution can be adjusted to display more pixels per centimetre. / Dissertation (MSc (Computer Science))--University of Pretoria, 2007. / Computer Science / unrestricted
152

Wildfire Management in the Southside Region of Canada’s Montane Cordillera - A Systems Modelling Application on Firebreak Strategies

Kessels, Henricus January 2016 (has links)
There is growing recognition of the importance of preserving Canada’s forests. Canada’s 348 million hectares of forest land cover 35% of its land area, representing 9% of the world’s forests and 24% of the world’s boreal forests. As a renewable resource, forests offer significant environmental, economic and recreational benefits and innumerable services contributing to the quality of life. Canada has recently entered an era of increased frequency and severity of natural disasters. Ecosystems and communities especially in western Canada have recently undergone a trend of increasing pressures from natural disturbances. These disturbances include wildfires associated with increased fuel load levels from past fire suppression regimes and a widely spread infestation of the mountain pine beetle in addition to changes in weather patterns. Wildfire activity has reached extreme levels in many of the recent years. This thesis profiles an area of western Canada within the Montane Cordillera covering the Nechako Lakes Electoral District in central British Columbia and assesses its vulnerability to the specific hazard of wildfires caused by natural and man-made sources. The objectives of this research are to review, simulate and assess the impact of various fuel management strategies in a sub-section of the Nechako Lakes Electoral District called the Southside. Values at risk include private property and old growth forest in respectively timber supply areas, provincial parks, woodlots and community forests. Simulation results show that firebreaks are effective in significantly reducing the area burned in different parts of the landscape. The performance of different strategies shows large variation. Although this has not been investigated further, such variation has likely been caused by topographic aspects and the positioning of firebreaks in the landscape in relation to climatic parameters. These results can therefore not be extrapolated beyond the simulated area, but do give an indication of the performance variation that may be expected when similar firebreaks are applied elsewhere. The results also show that model performance of all firebreak strategies is heavily and fairly consistently influenced by weather stream parameters. Sensitivity analyses of weather stream parameters show that although the reduction in total area burned varies, the ranking between strategies in their overall performance is consistent regardless of the weather pattern. Combined dry, warm and windy weather conditions lead to a 3.44-fold increase in total area burned as compared to the scenario with average weather conditions. In favourable weather conditions represented by wet, cold and nearly windless conditions, the model shows an 85% reduction in total burned area as compared to the average scenario. These results illustrate the significant impact of uncontrollable variables on the overall result.
153

Geografický IS jako Decision Support System / Geographical IS as Decision Support System

Hlaváč, Vít January 2009 (has links)
This thesis deals relationship between geographical information systems and decision support systems. Its objective is to verify hypothesis, if it is possible to consider geographical information systems as decision support systems. Opening chapter attends to explanation what is GIS and its usage in practise. Second part is engaged in definition of decision support systems. There are some examples from practise, which help us confirm or refuse the hypothesis, in the last chapter.
154

Využití mapových podkladů při řešení reportingu / Use of maps in reporting

Huňa, Tomáš January 2011 (has links)
The main objective of this thesis is to describe working with spatial data and their use in reports. The author focuses mainly on the MS SQL Server 2008 R2 platform. The first part deals with theoretical foundations. Defines the concept of Location Intelligence and describes its history to the present. It also addresses the benefits of Location Intelligence in various sectors and the relationship with Business Intelligence. Further theoretical part goes on to describe both spatial data at a general level and at the level of MS SQL Server 2008 R2. In addition, it described the use of ESRI Shapefile files and work with these files. From the description of spatial data author goes on to use reporting tools in Microsoft - SQL Server Reporting Services and Report Builder. Possible forms of map visualization and a detailed description of the settings are at the end of the theoretical part. The second part is focused on solving practical problems. Tools that are described in the theoretical part, are used to create report examples that the author at the beginning of this section set out to create.
155

Lokační data se zaměřením na oblast retailu / Spatial data for retail business

Kalus, Vilém January 2014 (has links)
The specialization of the final master thesis is theory and a practical view of Location Intelligence. The author is writing about specific parts of development of the application which is focused on analysis of consumer's behaviour for managers of retail businesses focused on customer's satisfaction. The application is a new way of researching consumer's behaviour. Spatial data is connected with the subject of research -- analysis of the movement of consumers in retail stores. The application is a practical tool for better targeting for managers or marketing specialists. The app was developed by four researcher Martin Matějka, Tomáš Rosenberger, Vilém Kalus (three diploma researchers) and Ondřej Funiok. The Main goal of the final thesis was to describe the application from the business point of view and to design layout of the user interface. The business model helped us to specify the application from the business point of view. We reached the main goal with research articles of Location Intelligence. The thesis contains theory basis of informatics and geo-informatics field, Business Intelligence, Location Intelligence and selected business models. The practical part of the thesis is composed of integrating application to the business model, functionality description. From functionality description we designed the user interface. The practical part closes with the use case of application in Vysoká škola ekonomická v Praze. Benefits of the thesis are in development of real, new application for future commercial use. Contribution to the theory of Location Intelligence and analytical solution of development of user interface.
156

A Language and Visual Interface to Specify Complex Spatial Pattern Mining

Li, Xiaohui 12 1900 (has links)
The emerging interests in spatial pattern mining leads to the demand for a flexible spatial pattern mining language, on which easy to use and understand visual pattern language could be built. It is worthwhile to define a pattern mining language called LCSPM to allow users to specify complex spatial patterns. I describe a proposed pattern mining language in this paper. A visual interface which allows users to specify the patterns visually is developed. Visual pattern queries are translated into the LCSPM language by a parser and data mining process can be triggered afterwards. The visual language is based on and goes beyond the visual language proposed in literature. I implemented a prototype system based on the open source JUMP framework.
157

The Ties that Bind Commanders : A study of sexual violence and restraint by rebel groups in Africa

Wieselgren, Herman January 2020 (has links)
An emerging literature on rebel groups’ restraint in the use of sexual violence has begun to explore the role of the commander. This study seeks to build on this literature by investigating under what conditions rebel commanders will enforce restraint. I argue that perpetrating sexual violence against civilian communities to which a rebel group has ethnic ties is highly costly for the rebel commander. Thus, commanders will strive to enforce restraint in the use of sexual violence against co-ethnic civilians. However, their ability to enforce restraint, I argue, hinges on the authority and influence they have over their combatants. Hence, I hypothesize that rebel groups with strong commanders are more likely to enforce restraint toward co-ethnic civilians. This argument is examined through unique spatial data on the geographic patterns of rebel sexual violence combined with spatial data on rebel groups’ co-ethnic civilian populations in Africa 1989-2009. Regression analysis finds that rebel groups with strong commanders and ethnic ties are less likely to perpetrate sexual violence against co-ethnics, yet also that groups with weak commanders are more likely to victimize co-ethnics.
158

Data Fusion in Spatial Data Infrastructures

Wiemann, Stefan 28 October 2016 (has links)
Over the past decade, the public awareness and availability as well as methods for the creation and use of spatial data on the Web have steadily increased. Besides the establishment of governmental Spatial Data Infrastructures (SDIs), numerous volunteered and commercial initiatives had a major impact on that development. Nevertheless, data isolation still poses a major challenge. Whereas the majority of approaches focuses on data provision, means to dynamically link and combine spatial data from distributed, often heterogeneous data sources in an ad hoc manner are still very limited. However, such capabilities are essential to support and enhance information retrieval for comprehensive spatial decision making. To facilitate spatial data fusion in current SDIs, this thesis has two main objectives. First, it focuses on the conceptualization of a service-based fusion process to functionally extend current SDI and to allow for the combination of spatial data from different spatial data services. It mainly addresses the decomposition of the fusion process into well-defined and reusable functional building blocks and their implementation as services, which can be used to dynamically compose meaningful application-specific processing workflows. Moreover, geoprocessing patterns, i.e. service chains that are commonly used to solve certain fusion subtasks, are designed to simplify and automate workflow composition. Second, the thesis deals with the determination, description and exploitation of spatial data relations, which play a decisive role for spatial data fusion. The approach adopted is based on the Linked Data paradigm and therefore bridges SDI and Semantic Web developments. Whereas the original spatial data remains within SDI structures, relations between those sources can be used to infer spatial information by means of Semantic Web standards and software tools. A number of use cases were developed, implemented and evaluated to underpin the proposed concepts. Particular emphasis was put on the use of established open standards to realize an interoperable, transparent and extensible spatial data fusion process and to support the formalized description of spatial data relations. The developed software, which is based on a modular architecture, is available online as open source. It allows for the development and seamless integration of new functionality as well as the use of external data and processing services during workflow composition on the Web. / Die Entwicklung des Internet im Laufe des letzten Jahrzehnts hat die Verfügbarkeit und öffentliche Wahrnehmung von Geodaten, sowie Möglichkeiten zu deren Erfassung und Nutzung, wesentlich verbessert. Dies liegt sowohl an der Etablierung amtlicher Geodateninfrastrukturen (GDI), als auch an der steigenden Anzahl Communitybasierter und kommerzieller Angebote. Da der Fokus zumeist auf der Bereitstellung von Geodaten liegt, gibt es jedoch kaum Möglichkeiten die Menge an, über das Internet verteilten, Datensätzen ad hoc zu verlinken und zusammenzuführen, was mitunter zur Isolation von Geodatenbeständen führt. Möglichkeiten zu deren Fusion sind allerdings essentiell, um Informationen zur Entscheidungsunterstützung in Bezug auf raum-zeitliche Fragestellungen zu extrahieren. Um eine ad hoc Fusion von Geodaten im Internet zu ermöglichen, behandelt diese Arbeit zwei Themenschwerpunkte. Zunächst wird eine dienstebasierten Umsetzung des Fusionsprozesses konzipiert, um bestehende GDI funktional zu erweitern. Dafür werden wohldefinierte, wiederverwendbare Funktionsblöcke beschrieben und über standardisierte Diensteschnittstellen bereitgestellt. Dies ermöglicht eine dynamische Komposition anwendungsbezogener Fusionsprozesse über das Internet. Des weiteren werden Geoprozessierungspatterns definiert, um populäre und häufig eingesetzte Diensteketten zur Bewältigung bestimmter Teilaufgaben der Geodatenfusion zu beschreiben und die Komposition und Automatisierung von Fusionsprozessen zu vereinfachen. Als zweiten Schwerpunkt beschäftigt sich die Arbeit mit der Frage, wie Relationen zwischen Geodatenbeständen im Internet erstellt, beschrieben und genutzt werden können. Der gewählte Ansatz basiert auf Linked Data Prinzipien und schlägt eine Brücke zwischen diensteorientierten GDI und dem Semantic Web. Während somit Geodaten in bestehenden GDI verbleiben, können Werkzeuge und Standards des Semantic Web genutzt werden, um Informationen aus den ermittelten Geodatenrelationen abzuleiten. Zur Überprüfung der entwickelten Konzepte wurde eine Reihe von Anwendungsfällen konzipiert und mit Hilfe einer prototypischen Implementierung umgesetzt und anschließend evaluiert. Der Schwerpunkt lag dabei auf einer interoperablen, transparenten und erweiterbaren Umsetzung dienstebasierter Fusionsprozesse, sowie einer formalisierten Beschreibung von Datenrelationen, unter Nutzung offener und etablierter Standards. Die Software folgt einer modularen Struktur und ist als Open Source frei verfügbar. Sie erlaubt sowohl die Entwicklung neuer Funktionalität durch Entwickler als auch die Einbindung existierender Daten- und Prozessierungsdienste während der Komposition eines Fusionsprozesses.
159

Fusion von Geodaten unterschiedlicher Quellen in Geodateninfrastrukturen am Beispiel von ATKIS und OpenStreetMap

Wiemann, Stefan 10 December 2009 (has links)
Die Zusammenführung von Geodaten auf Basis homologer Objekte ist ein wichtiger Teilprozess zur Wissensgenerierung aus verfügbaren Geoinformationen. Forschungen im Bereich der digitalen Geodatenfusion gibt es bereits seit Anfang der 80er Jahre. Das Aufgabenspektrum umfasst dabei die Aktualisierung, Veränderungsdetektion, Informationsanreicherung und Integration verfügbarer Datensätze. Gleichzeitig vollzieht sich seit Ende der 90er Jahre ein Paradigmenwechsel hin zum Aufbau dienstebasierter Geoinformationslandschaften auf Basis serviceorientierter Architekturen (SOA). Dieser wird insbesondere durch die Entwicklung einer Geodateninfrastruktur (GDI) im öffentlichen Sektor forciert und bildet einen Schwerpunkt der aktuellen Forschung im Bereich Geoinformatik. Innerhalb dieser interoperablen Strukturen kann ein entscheidender Informationsmehrwert durch die Kombination thematisch verwandter Ressourcen geschaffen werden. Die Fusion von Daten wird daher einen zentralen Bestandteil zukünftiger Entwicklungen im Bereich Web-basierter Anwendungen darstellen. Zur Bereitstellung von Geodaten in einer GDI hat das Open Geospatial Consortium (OGC) bereits zahlreiche Standards veröffentlicht. Darüber hinaus eröffnet die Entwicklung des Web 2.0 weitere, oftmals Community-gestützte, Möglichkeiten zur Bereitstellung von Geodaten außerhalb standardisierter GDI. Die Verarbeitung dieser Geodaten kann durch die Einführung des OGC Web Processing Service (WPS) realisiert werden. Diese Schnittstellenspezifikation ermöglicht die Verlagerung von Geoprozessierungsfunktionalitäten in eine GDI und trägt somit zur Ablösung monolithischer Geoinformationssysteme (GIS) durch verteilte dienstebasierte Strukturen bei. Für die Umsetzung komplexer Prozesse wie einer Geodatenfusion ist die Verfügbarkeit, Interoperabilität und Verkettung beteiligter Dienste von entscheidender Bedeutung. Nach der Einführung in Grundlagen von GDI und Geodatenfusion werden in dieser Arbeit Systemarchitektur und Bestandteile einer dienstebasierten Geodatenfusion konzipiert. Im Anschluss erfolgt die Beschreibung einer proof-ofconcept Implementierung wesentlicher Bestandteile unter Nutzung des 52°North WPS-Framework. Gegenstand der Implementierung ist die Fusion von Straßendaten der Modelle ATKIS (Amtliches Topographisch-Kartographisches Informationssystem) und OSM (OpenStreetMap) durch einen Feature- und Attributtransfer. Die Metadatenverarbeitung, Generalisierung und Evaluierung im Kontext einer dienstebasierten Geodatenfusion stellen weitere Teilaspekte dieser Arbeit dar. / The conflation of spatial data is one important task concerning the generation of knowledge from available geo-information. Research in this domain has been carried out since the early 80s and incorporates updating, change detection, enhancement and integration of spatial data. At the same time a paradigm shift leads towards service-oriented Architectures (SOA) in the field of geoinformation science. In the public sector this change is promoted by the developement of spatial data infrastructures (SDI). Especially whithin these interoperable structures, the combination of thematically comparable ressources can be used to enhance available spatial information. The conflation of data in general represents a core component of future research on web-based applications. The Open Geospatial Consortium (OGC) has already published various standards for spatial data dissemination. In addition, the Web 2.0 developement offers the possibility of user-generated spatial data beyond standardized SDI. The conflation of institutional- and community-provided datasets can be realized by the introduction of the OGC Web Processing Service (WPS). The WPS interface offers geoprocessing capabilities within SDI and thus helps distributed serviceoriented environments to replace monolithic Geographic Information Systems. Availibility, interoperability and chaining of services are crucial for implementing complex processes, such as conflation. After an introduction to the fundamentals of SDI and conflation, a servicebased architecture for geodata conflation will be developed within this thesis. The proof-of-concept implementation is realized using the 52°North WPS and exercises the conflation of street data. For this purpose, the data models ATKIS (Authoritative Topographic Cartographic Information System) and OSM (OpenStreetMap) were applied to perform a transfer of attributes and features. Other important aspects of this thesis related to service-based conflation include the processing of metadata, generalization and evaluation.
160

Bezpečnost publikování prostorových dat na Internetu / Security of publishing spatial data on Internet

Břichnáč, Pavel January 2010 (has links)
Bezpečnost publikování prostorových dat na internetu Abstrakt Diplomová práce se věnuje problematice publikování prostorových dat v síti internet. Cílem je popsat soudobé způsoby publikování dat, analyzovat bezpečnostní slabiny z hlediska úniku dat a navrhnout opatření, která by umožnila zabezpečit volně dostupná data proti automatizovanému stahování. V práci je vysvětlena motivace ilegálního získávání prostorových dat, jsou popsány soudobé možnosti publikování dat na internetu (včetně specifik pro data rastrová a vektorová), možnosti ochrany dat proti nelegálnímu získání a jejich slabiny. Výsledkem je navržení a formulování obecné metodiky ve formě doporučení pro publikování různých typů prostorových dat, která automatizované útoky na získání dat významně ztíží. Klíčová slova: prostorová data, internet, mapový server, datová politika, webové technologie Security of publishing spatial data on the Internet Abstract The master's thesis focuses on the topics of security of publishing spatial data on the Internet. The goal of the work is to describe present ways of publishing, to analyze weaknesses from point of view of leaks and to propose measures, that would allow securing publicly accessible data against automated downloads. Readers will get explained the motivation of getting spatial data, description and...

Page generated in 0.0897 seconds