• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 78
  • 60
  • 27
  • 27
  • 20
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 276
  • 43
  • 32
  • 29
  • 27
  • 24
  • 23
  • 22
  • 21
  • 21
  • 20
  • 20
  • 20
  • 19
  • 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.
31

Visualising attribute and spatial uncertainty in choropleth maps using hierachical spatial data models

Kardos, Julian, n/a January 2006 (has links)
This thesis defines a novel and intuitive method to visually represent attribute uncertainty, and spatial boundary uncertainty generated from choropleth maps. Like all data, it is not possible to know exactly how far from the truth spatial data used for choropleth mapping is. When spatial data is used in a decision-making context a visual representation of data correctness may become a valuable addition. As an example, the visualisation of uncertainty is illustrated using choropleth mapping techniques superimposed on New Zealand 2001 census data, but other spatial datasets could have been employed. Both attribute and spatial uncertainty are considered, with Monte Carlo statistical simulations being used to model attribute uncertainty. A visualisation technique to manage certain choropleth spatial boundary issues (i.e. the modifiable areal unit problem - MAUP) and uncertainty in attribute data is introduced, especially catering for attribute and choropleth spatial boundary uncertainty simultaneously. The new uncertainty visualisation method uses the quadtree spatial data model (SDM) in a novel manner. It is shown that by adapting the quadtree SDM to divide according to uncertainty levels possessed by attributes (associated with areal units), rather than divide on the basis of homogeneous regions (as the original quadtree design was intended), a measure of attribute and choropleth spatial boundary uncertainty can be exhibited. The variable cell size of the structure expresses uncertainty, with larger cell size indicating large uncertainty, and vice versa. The new quadtree SDM was termed the trustree. A software suite called TRUST v1.0 (The Representation of Uncertainty using Scale-unspecific Tessellations) was developed to create square trustree visualisations. The visual appeal and representational accuracy of the trustree was investigated. Representative accuracy and visual appeal increased when using hexagonal tessellations instead of the quadtree�s traditional square tessellation. In particular, the Hexagonal or Rhombus (HoR) quadtree designed by Bell et al. (1989) was used to programme TRUST v1.1. Using the HoR quadtree in rhombic mode (TRUST v1.1.1) produced Orbison�s optical illusion, so it was disregarded. However, the HoR trustree (the hexagonal tessellation produced by TRUST v1.1.2) was adopted for further research and user assessment. When assessed using an Internet survey, the HoR trustree adequately displayed choropleth spatial boundary uncertainty, but not attribute uncertainty. New trustree visualisations, the value-by-area (VBA) trustree and adjacent HoR trustree were developed to help increase the expression of attribute uncertainty. Upon reassessment, the new trustree visualisations were deemed usable to express attribute uncertainty and choropleth spatial boundary uncertainty at a modest 58% usable (HoR trustree), 80% usable (VBA trustree) and 85% usable (adjacent HoR trustree). A usability test (where participants were asked to spot different levels of uncertainty) validated these results, whereby the HoR trustree achieved a 65% accuracy level and the VBA trustree achieved an 80% accuracy level. The user assessments helped to highlight that the trustree could be used in two ways, to express detail within or clutter over areal units. The HoR trustree showed (1) a level of detail (or resolution) metaphor, where more detail represented more accuracy and/or the reverse, (2) a metaphor of clutter, where the data structure output was sufficiently dense as to cover spatial information, in effect hiding uncertain areas. Further Internet survey testing showed the trustree tessellation works better when representing a metaphor of detail. Attribute and spatial uncertainty can be effectively expressed depending on the tessellation level used. Overall, the new TRUST suite visualisations compare favourably with existing uncertainty visualisation techniques. Some uncertainty visualisation methods consistently performed better than the TRUST visualisations such as blinking areas, adjacent value and non-continuous cartograms. Other methods like colour saturation, image sharpness and a three-dimensional surface frequently performed with less usability. Therefore, the TRUST visualisations have found their place amongst other uncertainty visualisation methods. However, survey results showed that TRUST is a viable option for visualising two forms of uncertainty - attribute and spatial uncertainty. No other visualisation method has these capabilities. Further research could include a laboratory assessment of TRUST and also incorporating vagueness and temporal uncertainty concepts. Additionally, end-user testing could provide a valuable insight into uncertainty visualisation for everyday use. Adopting uncertainty methods to uncertainty, such as the technique presented here, into the mainstream decision making environment could be considered a fundamental objective for future investigation in spatial studies.
32

The end of the mandatory long form census: anticipated implications for planning

Jerez, Simi 14 September 2012 (has links)
In June 2010, Canada’s Conservative majority government made a controversial announcement that the mandatory long form Census of Canada questionnaire would be replaced by the voluntary National Household Survey, as the former was deemed to be too invasive to Canadians’ privacy, threatening imprisonment for non-compliance. This practicum examines the anticipated implications of the Census change through an analysis of existing information – the repository of letters either supporting or contesting the elimination of the mandatory questionnaire. Planning processes are contingent upon understanding socio-economic conditions and demographic distribution. The long form Census is arguably an integral planning tool that provides an indication of community change. This research explores the role of information with respect to planning processes and the use of knowledge in enabling power within or over communities. Finally, this practicum provides suggestions for planners to mitigate changes to statistical information and adapt planning processes.
33

The end of the mandatory long form census: anticipated implications for planning

Jerez, Simi 14 September 2012 (has links)
In June 2010, Canada’s Conservative majority government made a controversial announcement that the mandatory long form Census of Canada questionnaire would be replaced by the voluntary National Household Survey, as the former was deemed to be too invasive to Canadians’ privacy, threatening imprisonment for non-compliance. This practicum examines the anticipated implications of the Census change through an analysis of existing information – the repository of letters either supporting or contesting the elimination of the mandatory questionnaire. Planning processes are contingent upon understanding socio-economic conditions and demographic distribution. The long form Census is arguably an integral planning tool that provides an indication of community change. This research explores the role of information with respect to planning processes and the use of knowledge in enabling power within or over communities. Finally, this practicum provides suggestions for planners to mitigate changes to statistical information and adapt planning processes.
34

Visualising attribute and spatial uncertainty in choropleth maps using hierachical spatial data models

Kardos, Julian, n/a January 2006 (has links)
This thesis defines a novel and intuitive method to visually represent attribute uncertainty, and spatial boundary uncertainty generated from choropleth maps. Like all data, it is not possible to know exactly how far from the truth spatial data used for choropleth mapping is. When spatial data is used in a decision-making context a visual representation of data correctness may become a valuable addition. As an example, the visualisation of uncertainty is illustrated using choropleth mapping techniques superimposed on New Zealand 2001 census data, but other spatial datasets could have been employed. Both attribute and spatial uncertainty are considered, with Monte Carlo statistical simulations being used to model attribute uncertainty. A visualisation technique to manage certain choropleth spatial boundary issues (i.e. the modifiable areal unit problem - MAUP) and uncertainty in attribute data is introduced, especially catering for attribute and choropleth spatial boundary uncertainty simultaneously. The new uncertainty visualisation method uses the quadtree spatial data model (SDM) in a novel manner. It is shown that by adapting the quadtree SDM to divide according to uncertainty levels possessed by attributes (associated with areal units), rather than divide on the basis of homogeneous regions (as the original quadtree design was intended), a measure of attribute and choropleth spatial boundary uncertainty can be exhibited. The variable cell size of the structure expresses uncertainty, with larger cell size indicating large uncertainty, and vice versa. The new quadtree SDM was termed the trustree. A software suite called TRUST v1.0 (The Representation of Uncertainty using Scale-unspecific Tessellations) was developed to create square trustree visualisations. The visual appeal and representational accuracy of the trustree was investigated. Representative accuracy and visual appeal increased when using hexagonal tessellations instead of the quadtree�s traditional square tessellation. In particular, the Hexagonal or Rhombus (HoR) quadtree designed by Bell et al. (1989) was used to programme TRUST v1.1. Using the HoR quadtree in rhombic mode (TRUST v1.1.1) produced Orbison�s optical illusion, so it was disregarded. However, the HoR trustree (the hexagonal tessellation produced by TRUST v1.1.2) was adopted for further research and user assessment. When assessed using an Internet survey, the HoR trustree adequately displayed choropleth spatial boundary uncertainty, but not attribute uncertainty. New trustree visualisations, the value-by-area (VBA) trustree and adjacent HoR trustree were developed to help increase the expression of attribute uncertainty. Upon reassessment, the new trustree visualisations were deemed usable to express attribute uncertainty and choropleth spatial boundary uncertainty at a modest 58% usable (HoR trustree), 80% usable (VBA trustree) and 85% usable (adjacent HoR trustree). A usability test (where participants were asked to spot different levels of uncertainty) validated these results, whereby the HoR trustree achieved a 65% accuracy level and the VBA trustree achieved an 80% accuracy level. The user assessments helped to highlight that the trustree could be used in two ways, to express detail within or clutter over areal units. The HoR trustree showed (1) a level of detail (or resolution) metaphor, where more detail represented more accuracy and/or the reverse, (2) a metaphor of clutter, where the data structure output was sufficiently dense as to cover spatial information, in effect hiding uncertain areas. Further Internet survey testing showed the trustree tessellation works better when representing a metaphor of detail. Attribute and spatial uncertainty can be effectively expressed depending on the tessellation level used. Overall, the new TRUST suite visualisations compare favourably with existing uncertainty visualisation techniques. Some uncertainty visualisation methods consistently performed better than the TRUST visualisations such as blinking areas, adjacent value and non-continuous cartograms. Other methods like colour saturation, image sharpness and a three-dimensional surface frequently performed with less usability. Therefore, the TRUST visualisations have found their place amongst other uncertainty visualisation methods. However, survey results showed that TRUST is a viable option for visualising two forms of uncertainty - attribute and spatial uncertainty. No other visualisation method has these capabilities. Further research could include a laboratory assessment of TRUST and also incorporating vagueness and temporal uncertainty concepts. Additionally, end-user testing could provide a valuable insight into uncertainty visualisation for everyday use. Adopting uncertainty methods to uncertainty, such as the technique presented here, into the mainstream decision making environment could be considered a fundamental objective for future investigation in spatial studies.
35

Viabilidade da utilização do Google Earth na construção de mapas de setores urbanos para fins censitários. / Feasibility of using Google Earth in the construction of maps of urban areas for census.

José Henrique da Silva 21 October 2009 (has links)
A história dos Censos no Brasil mostra que a preocupação com a componente territorial em levantamentos estatísticos, surgiu no recenseamento de 1940, quando, pela primeira vez, o IBGE procurou retratar aspectos da realidade geográfica, de interesse para a operação de coleta, em bases cartográficas, uma tarefa complexa devido à grande extensão do território brasileiro e principalmente no que se refere à qualidade do material cartográfico disponível à época. Atualmente crescem as demandas em nosso país, por informações cada vez mais detalhadas e geograficamente posicionadas. Governadores e prefeitos, órgãos de planejamento municipais e estaduais, investidos de maior autonomia e de novas responsabilidades após a Constituição de 1988, dependem hoje como nunca dos censos para definirem suas políticas públicas, com base em informações atualizadas sobre a população sob suas jurisdições. Entretanto, as demandas por informações agregadas à posição também vêm de outras esferas, que vão do setor não-governamental e privado ao governo federal, fazendo com que muito aumentasse a relevância dos censos e por conseqüência os resultados das pesquisas. Para atender a grande demanda, o IBGE vem continuamente aperfeiçoando o que denominamos de Base Territorial, que é um sistema integrado de informações de natureza geográfica e alfanumérica e se constitui no principal requisito para a garantia da adequada cobertura das operações de levantamento censitário. Face a este novo cenário, o IBGE iniciou a elaboração de mapas da base territorial em meio digital, durante as ações preparatórias para o Censo 2000, se deparando com as dificuldades de integração das áreas urbanas e rurais e a baixa qualidade dos insumos de mapeamento em escala cadastral, disponível nas áreas menos desenvolvidas, pois a Instituição não é produtora de mapeamento em escala cadastral. A metodologia proposta visa melhorar a qualidade dos Mapas de Setores Urbanos MSU, com a utilização de imagens Google Earth, a partir software MicroStation 95, periféricos e aplicativos de conversão disponíveis no IBGE, com o estabelecimento de uma nova rotina de trabalho para produção e substituição dos mapas de setores urbanos, de forma a garantir uma maior representatividade territorial dos dados estatísticos para divulgação. / The history of census in Brazil shows that the worry with the territorial component in statistical surveys appeared in the 1940 Census. For the first time the Brazilian Institute for Geography and Statistics (IBGE) tried to describe aspects of the geographic reality, of interest for the assembling operation in cartographic basis a complex task due to the great extension of the Brazilian territory and mainly in relation to the quality of the cartographic material available at that time. Nowadays in our country the demands for more detailed and geographically positioned data grow governors and majors, planning institutes at municipal and state levels, owners of more autonomy and new responsibilities after the 1988 Constitution depend today as never before on the census to define their public policies based on up-dated data on the population under their jurisdictions.Nevertheless the demands for date linked to the position come also from other areas which range from the non-governmental and private sector of the Federal Government increasing the importance of census and by consequence the results of the researches. To respond to the great demand, the IBGE continuously implement the so-called Territorial Base, which is an integrated data system of geographical nature and alfa-numerical and it is the main requisite for the warrant of the adequate cover of the census operations. Due to this new scenery, IBGE started the elaboration of maps of the territorial base through digital means during the preparation actions for the 2000 Census, facing difficulties concerning the integration of urban and rural areas and the low quality of mapping data in cadastral scale, available in less developed areas once the institution does not produce in a cadastral scale.The methodology proposed aims at improving the quality of Urban Sectors Maps MSU, using the Google Earth images, from the software Micro Station 95, peripheric and applicative of conversion available at IBGE, with the establishment of a new routine of work for the production and replacement of the maps of the urban sectors, in order to guarantee a greater territorial representativeness of statistical data for dissemination.
36

Viabilidade da utilização do Google Earth na construção de mapas de setores urbanos para fins censitários. / Feasibility of using Google Earth in the construction of maps of urban areas for census.

José Henrique da Silva 21 October 2009 (has links)
A história dos Censos no Brasil mostra que a preocupação com a componente territorial em levantamentos estatísticos, surgiu no recenseamento de 1940, quando, pela primeira vez, o IBGE procurou retratar aspectos da realidade geográfica, de interesse para a operação de coleta, em bases cartográficas, uma tarefa complexa devido à grande extensão do território brasileiro e principalmente no que se refere à qualidade do material cartográfico disponível à época. Atualmente crescem as demandas em nosso país, por informações cada vez mais detalhadas e geograficamente posicionadas. Governadores e prefeitos, órgãos de planejamento municipais e estaduais, investidos de maior autonomia e de novas responsabilidades após a Constituição de 1988, dependem hoje como nunca dos censos para definirem suas políticas públicas, com base em informações atualizadas sobre a população sob suas jurisdições. Entretanto, as demandas por informações agregadas à posição também vêm de outras esferas, que vão do setor não-governamental e privado ao governo federal, fazendo com que muito aumentasse a relevância dos censos e por conseqüência os resultados das pesquisas. Para atender a grande demanda, o IBGE vem continuamente aperfeiçoando o que denominamos de Base Territorial, que é um sistema integrado de informações de natureza geográfica e alfanumérica e se constitui no principal requisito para a garantia da adequada cobertura das operações de levantamento censitário. Face a este novo cenário, o IBGE iniciou a elaboração de mapas da base territorial em meio digital, durante as ações preparatórias para o Censo 2000, se deparando com as dificuldades de integração das áreas urbanas e rurais e a baixa qualidade dos insumos de mapeamento em escala cadastral, disponível nas áreas menos desenvolvidas, pois a Instituição não é produtora de mapeamento em escala cadastral. A metodologia proposta visa melhorar a qualidade dos Mapas de Setores Urbanos MSU, com a utilização de imagens Google Earth, a partir software MicroStation 95, periféricos e aplicativos de conversão disponíveis no IBGE, com o estabelecimento de uma nova rotina de trabalho para produção e substituição dos mapas de setores urbanos, de forma a garantir uma maior representatividade territorial dos dados estatísticos para divulgação. / The history of census in Brazil shows that the worry with the territorial component in statistical surveys appeared in the 1940 Census. For the first time the Brazilian Institute for Geography and Statistics (IBGE) tried to describe aspects of the geographic reality, of interest for the assembling operation in cartographic basis a complex task due to the great extension of the Brazilian territory and mainly in relation to the quality of the cartographic material available at that time. Nowadays in our country the demands for more detailed and geographically positioned data grow governors and majors, planning institutes at municipal and state levels, owners of more autonomy and new responsibilities after the 1988 Constitution depend today as never before on the census to define their public policies based on up-dated data on the population under their jurisdictions.Nevertheless the demands for date linked to the position come also from other areas which range from the non-governmental and private sector of the Federal Government increasing the importance of census and by consequence the results of the researches. To respond to the great demand, the IBGE continuously implement the so-called Territorial Base, which is an integrated data system of geographical nature and alfa-numerical and it is the main requisite for the warrant of the adequate cover of the census operations. Due to this new scenery, IBGE started the elaboration of maps of the territorial base through digital means during the preparation actions for the 2000 Census, facing difficulties concerning the integration of urban and rural areas and the low quality of mapping data in cadastral scale, available in less developed areas once the institution does not produce in a cadastral scale.The methodology proposed aims at improving the quality of Urban Sectors Maps MSU, using the Google Earth images, from the software Micro Station 95, peripheric and applicative of conversion available at IBGE, with the establishment of a new routine of work for the production and replacement of the maps of the urban sectors, in order to guarantee a greater territorial representativeness of statistical data for dissemination.
37

Proposta metodológica para aplicação de sistemas de informação geográfica na cartografia pós-censo em Moçambique

RIBEIRO, Ester Tomás Natal 26 February 2015 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-11-16T12:57:09Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ester Tomas Natal Ribeiro (1).pdf: 7180685 bytes, checksum: 97d4738d1134faf13fa96c08d582a5e9 (MD5) / Made available in DSpace on 2017-11-16T12:57:10Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Ester Tomas Natal Ribeiro (1).pdf: 7180685 bytes, checksum: 97d4738d1134faf13fa96c08d582a5e9 (MD5) Previous issue date: 2015-02-26 / O censo é uma operação estatística complexa que um país executa de dez em dez anos e exerce um papel fundamental na obtenção de dados sobre a população. Os dados obtidos pelo censo são usados para o planejamento do país e em diversas áreas de pesquisa. Para que os dados sejam fiáveis é necessário que no âmbito da concepção do projeto se defina as estratégias de execução desde a fase pré-censo, censo e pós-censo. A fase pós-censo, que é o foco desta pesquisa, caracteriza-se pelo tratamento dos dados coletados no campo durante o censo e disseminação dos resultados em forma de tabelas, gráficos, mapas, dentre outros. Para esta pesquisa, foram selecionados 11 indicadores que fazem parte dos dez temas publicados por províncias em forma de quadros nas disseminações definitivas do censo 2007. Os indicadores foram modelados, foi criada uma base de dados espaciais e representados através de mapas em 11 províncias que compõem Moçambique. A modelagem consistiu na elaboração do modelo conceitual em ArgoUML, um software livre e de código aberto. Devido a restrições impostas pelo ArgoUML foi utilizado o DBDesigner Fork, software livre de código aberto, que permitiu a geração do modelo entidade-relacionamento e de Script SQL. Por meio do comando SQL no pgAdmim III foi possível executar o Script SQL e implementar a base de dados do censo em forma de tabelas. Após a implementação foi possível observar toda a modelagem elaborada. A representação espacial dos indicadores também foi feita a partir de software livre de código aberto - Quantum GIS. A partir dos mapas elaborados foi feita a análise dos indicadores por província e observou-se que as províncias do centro e norte de Moçambique apresentam baixos resultados em relação às províncias localizadas no sul. / The census is a complex statistical operation that a country runs every ten years and plays a key role in obtaining data on the population. The data obtained by the Census in a country are used for planning and also in several areas of research. For data to be reliable it is necessary that, within the project design to define implementation strategies starting from pre-census phase, census and postcensus. The post-census phase, which is the focus of this research is characterized by the processing of data collected in the field during the census and disseminating the results in tables, graphs, maps, and other formats. For this research, we selected eleven indicators that are part of the ten subjects published per provinces in tabular format within the final disseminations in the 2007 census. The indicators were modeled, a spatial database was created and represented through maps in eleven provinces that comprise Mozambique. The modeling was to draw up the conceptual model in ArgoUML a free and open source software. Due to restrictions imposed by ArgoUML, the DBDesigner Fork was used, a free open source software, which allowed the generation of the entity-relationship model and the SQL script. Through SQL command in pgAdmim III was possible to run the SQL script and implement the census database in a table format. After implementation was possible to observe all the modeling done. The spatial representation of the indicators was also done through the free open source software - Quantum GIS. From the maps drawn up, an analysis of the indicators per province has been made and it was observed that the provinces of central and northern Mozambique have low results comparing to the provinces located in the south.
38

Historie a budoucnost sčítání lidu / History and future of population census

Máchová, Veronika January 2009 (has links)
This work deals with history, present and future of population census. There are the standpoits defined in the first chapter which the description of process of historic census is connected to. There are processes of census from ancient era to the last census in 2001 described in this work. From the beginning of Czech- Slovak Republic every census is described in more details. There are results about amount of populaced and achieved education mentioned in my assignment too. The part of the work is focused on detection of people's opinions on the last censuses and on the planned changes for census in 2011. Processed results are mentioned with absolute and relative numbers. The last chapter deals with upcoming census for year 2011.
39

A method for analyzing census data from small populations : developed, tested and applied to a 1958 census of Suba barrio, Paoay, Ilocos Norte, the Philippines

Million, Stephen Aulick 01 January 1979 (has links)
As part of his anthropological fieldwork, in January 1958 Daniel J. Scheans took a census of Suba, an Ilokano barrio in Paoay, Ilocos Norte, the Philippines. The purpose of the thesis was. to use the Suban data to develop, describe and.test a method for analyzing census data for small populations (1000 or fewer persons). The method was to be complete, to generate as much information as possible based on the data collected, to expose weaknesses and gaps in the data collected and in the data collection procedures, to aid future census-takers .in structuring the content of and procedures for taking a census, to be computerized for speed and ease of analysis and adjustment, and to furnish data sufficiently free from methodological variations to allow meaningful comparisons of different populations.
40

Remote access capability embedded in linked data using bi-directional transformation: issues and simulation

Malik, K.R., Farhan, M., Habib, M.A., Khalid, S., Ahmad, M., Ghafir, Ibrahim 24 January 2020 (has links)
No / Many datasets are available in the form of conventional databases, or simplified comma separated values. The machines do not adequately handle these types of unstructured data. There are compatibility issues as well, which are not addressed well to manage the transformation. The literature describes several rigid techniques that do the transformation from unstructured or conventional data sources to Resource Description Framework (RDF) with data loss and limited customization. These techniques do not present any remote way that helps to avoid compatibility issues among these data forms simultaneous utilization. In this article, a new approach has been introduced that allows data mapping. This mapping can be used to understand their differences at the level of data representations. The mapping is done using Extensible Markup Language (XML) based data structures as intermediate data presenter. This approach also allows bi-directional data transformation from conventional data format and RDF without data loss and with improved remote availability of data. This is a solution to the issue concerning update when dealing with any change in the remote environment for the data. Thus, traditional systems can easily be transformed into Semantic Web-based system. The same is true when transforming data back to conventional data format, i.e. Database (DB). This bidirectional transformation results in no data loss, which creates compatibility between both traditional and semantic form of data. It will allow applying inference and reasoning on conventional systems. The census un-employment dataset is used which is being collected from US different states. Remote bi-directional transformation is mapped on the dataset and developed linkage using relationships between data elements. This approach will help to handle both types of data formats to co-exist at the same time, which will create opportunities for data compatibility, statistical powers and inference on linked data found in remote areas.

Page generated in 0.0649 seconds