766 research outputs found

    A comprehensive view on quantity based aggregation for cadastral databases

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    Quantity Based Aggregation (QBA) control is a subject that is closely related to inference control in databases. The goal is to enforce k out of n disclosure control. In this paper we work on QBA problems in the context of cadastral databases: how to prevent a user from knowing 1) the owners of all parcels in a region, and 2) all parcels belonging to the same owner. This work combines and extends our previous work on the subject [1, 2, 3]. We overview the legislative context surrounding cadastral databases. We give important definitions related to the QBA concept. We present a complete model for QBA control in cadastral databases. We show how to implement the security policy efficiently, and we present our prototype of secure cadastral databases with some performance evaluations

    The Development of a bi-level geographic information systems (GIS) database model for informal settlement upgrading

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    Bibliography : leaves 348-369.Existing Urban GIS models are faced with several limitations. Firstly, these models tend to be single-scale in nature. They are usually designed to operate at either metropolitan- or at the local-level. Secondly, they are generally designed to cater only for the needs of the formal and environmental sectors of the city system. These models do not cater for the "gaps" of data that exist in digital cadastres throughout the world. In the developed countries, these gaps correspond to areas of physical decay or economic decline. In the developing countries, they correspond to informal settlement areas. In this thesis, a new two-scale urban GIS database model, termed the "Bi-Ievel model" is proposed. This model has been specifically designed to address these gaps in the digital cadastre. Furthermore, the model addresses the short-comings facing current informal settlement upgrading models by providing mechanisms for community participation, project management, creating linkages to formal and environmental sectoral models, and for co-ordinating initiatives at a global-level. The Bi-Ievel model is comprised of a metropolitan-level and a series of local-level database components. These components are inter-linked through bi-directional database warehouse connections. While the model requires Internet-connectivity to achieve its full potential across a metropolitan region, it recognises the need for community participation-based methods at a local-level. Members of the community are actually involved in capturing and entering informal settlement data into the local-level database

    Learning from 20 Years of Payments for Ecosystem Services in Costa Rica

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    Costa Rica's Payments for Ecosystems Services (PES) programme has become something of an icon in the world of conservation. Its innovative blend of economic and regulatory instruments - and its hitches and successes - provide a valuable source of inspiration for other countries that are looking for effective ways to conserve and regenerate ecosystems. Since 1997, nearly one million hectares of forest in Costa Rica have been part of the PES programme at one time or another, and forest cover has now returned to over 50 per cent of the country's land area, from a low of just 20 per cent in the 1980s. What lessons can be learnt from the 20 years since it was founded? Also published in Spanish, this paper is for local practitioners, international researchers and donors who are interested in the Costa Rican experience

    Towards Geo Decision Support Systems for Renewable Energy Outreach

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    La Tierra se encuentra afectada por numerosos fenómenos tales como los desastres naturales, sobre urbanización, contaminación, etc. Todas estas actividades afectan enormemente a los recursos naturales del planeta llevando a la escasez de los mismos. Un tema especialmente relevante es el uso exhaustivo de energía fósil y su impacto negativo sobre nuestro medio ambiente. Resulta de este modo fundamental la búsqueda de nuevos recursos energéticos limpios para satisfacer nuestras necesidades y reducir la dependencia de recursos energéticos fósiles. La transformación de una infraestructura de generación de energía basada en recursos fósiles a otra basada en recursos energéticos renovables tales como eólica, solar y energía hidroeléctrica llevará a un mejor mantenimiento del medio ambiente ya que supondrá poco o ningún efecto en el calentamiento global por las emisiones, y a una reducción de la dependencia de fuentes de energía fósil. Las energías renovables son una fuente natural de energía que tiene importantes beneficios ya que proporciona un sistema de producción de energía confiable, con precios de la energía estables, puestos de trabajo especializados, y beneficios económicos y el medio ambiente. La energía solar es una de las mejores energías renovables. El sol es la fuente natural y fundamental de la existencia humana sobre la tierra y afecta a todos los procesos químicos, físicos y biológicos. Una hora de la energía del sol en la tierra es suficiente para alimentar a todo el planeta durante un año. La energía del sol o la radiación solar y su presencia geográfica determinan posibles inversiones en energía solar y las estrategias de desarrollo de las mismas. De este modo es esencial para poder proporcionar respuestas relacionadas con el "qué, quién, cuando y donde". Por ejemplo: ¿Cuál es el perfil de trabajo que mejor adapta a una posición gerencial de las energías renovables? ¿Dónde está el mejor lugar para invertir en huertos solares y/o parques eólicos? ¿En qué fecha se registra la más alta productividad? ¿Por qué este lugar no es apto para proyectos hidráulicos? ¿Por qué hay un bajón en la radiación solar en el año 2000 frente a 2012? Etc. En general, la toma de decisiones es el proceso de seleccionar la mejor opción viable de un conjunto de posibles maneras de hacer las cosas. Los Sistemas de Soporte de Decisión (del inglés Decision Support System, DSS) constituyen un ecosistema cognitivo que facilita la interacción entre los seres humanos y los datos para facilitar de forma profunda, significativa y útil la creación de soluciones efectivas en tiempo y costes. Grandes almacenamientos de Datos (Data warehousing), procesos de Extracción, Transformación y Carga (del inglés Extract Transform and Load, ETL) y la Inteligencia de Negocios (del ingles Business Intelligence, BI) son aspectos tecnológicos clave vinculados a la toma de decisiones. Además, la toma de decisiones en el contexto de la energía solar depende de Sistemas de Información Geográfica. Aunque la energía del Sol está disponible en todo el mundo, es evidente que la energía solar es más abundante cerca de los trópicos. Por ejemplo, una inversión en plantas de energía fotovoltaica en lugares cerca de los trópicos y del ecuador requerirá menos tiempo para su amortización. Dependiendo de la ubicación geográfica y las condiciones climáticas, la intensidad solar varía. Por esta razón, es importante seleccionar la ubicación adecuada que optimice la inversión teniendo en cuenta factores como la intensidad de la radiación solar, clima, tierras aptas y economía. Hay modelos como Global atlas y SimuSOLAR que dan información de idoneidad sobre la radiación solar y las ubicaciones. Sin embargo, estos modelos están restringidos a expertos, cubren áreas geográficas limitadas, no son aptos para casos de uso diferentes de los inicialmente previstos, y adolecen de falta de informes detallados e intuitivos para el público en general. El desarrollo de una cartografía extensa sobre la relación de zonas de sol y de sombra es un trabajo muy complejo que involucra diversos conceptos y retos de ingeniería, necesitando de la integración de diferentes modelos de datos, de calidad y cantidad heterogéneas, con limitaciones presupuestarias, etc. El objetivo de los trabajos de investigación desarrollados ha sido establecer la arquitectura de software para el desarrollo de Sistemas de Soporte de Decisión en el ámbito de las energías renovables en general, y de la energía solar en particular. La característica clave de este enfoque de arquitectura de software es ser capaz de proporcionar Sistemas de Soporte de Decisión que ofrezcan servicios de bajo coste ("low cost") en este contexto. Hagamos una analogía. Imagínese que usted está buscando comprar o alquilar una casa en España. Quiere analizar las características del edificio (por ejemplo dimensiones, jardín, más de una edificación en la parcela) y su entorno (por ejemplo, conexiones, servicios). Para realizar esta tarea puede utilizar los datos gratuitos proporcionados por la Oficina Virtual del Catastro de España junto con imágenes libres de un proveedor de ortofotografías (por ejemplo PNOA, Google o Bing) y datos contextuales libres procedentes de otros organismos locales, regionales y/o nacionales (por ejemplo el Ayuntamiento de Zaragoza, el Gobierno de Aragón, el proyecto Cartociudad). Si alguien integra todos estos orígenes de datos en un sistema (por ejemplo el cliente del servicio de mapas de la Infraestructura de Datos Espaciales de España, IDEE), tiene un Sistema de Soporte de Decisión "low cost" para comprar o alquilar una casa. Este trabajo de investigación tiene como objetivo el desarrollo de un enfoque de arquitectura de software que podría proporcionar un Sistema de Soporte de Decisión "low cost" cuando los consumidores necesitan tomar decisiones relacionadas con las energías renovables, en particular sistemas de energía solar, como podría ser la selección de la mejor opción para instalar un sistema solar, o decidir una inversión en una granja solar comunitaria. Una parte importante de este proceso de investigación ha consistido en el análisis sobre la idoneidad de las tecnologías vinculadas a Grandes almacenamientos de Datos y procesos de Extracción, Transformación y Carga para almacenar y procesar gran cantidad de datos históricos referentes a la energía, e Inteligencia de Negocios para la estructuración y presentación de informes. Por otro lado, ha sido necesario centrar el trabajo en modelos de negocio abierto (infraestructura de servicios web, modelos de datos 3D, técnicas de representación de datos sobre zonas de sol y sombra, y fuentes de datos) para el desarrollo económico del producto. Además, este trabajo identifica casos de uso donde los Sistemas de Soporte de Decisión deben ser el instrumento de resolución de problemas de mercado y de problemas científicos. Por lo tanto, esta tesis tiene como objetivo enfatizar y adoptar las tecnologías citadas para proponer un Sistema de Soporte de Decisión completo para un mejor uso potencial de las energías renovables que denominamos REDSS (del inglés Renewable Energy Decision Support System). El trabajo de investigación ha sido desarrollado con el objeto de encontrar respuestas a las siguientes preguntas de investigación: Preguntas relacionadas a los datos: - ¿Cómo elegir el proceso de creación de datos más adecuado para crear modelos geográficos cuyo coste económico sea razonable? Preguntas relacionadas con la tecnología: - ¿Qué limitaciones tecnológicas actuales tienen las herramientas computacionales para el cálculo de la intensidad y sombra solar? - ¿Cómo se puede adaptar conceptos como Grandes almacenamientos de Datos y la Inteligencia de Negocios en el campo de las energías renovables? - ¿Cómo estructurar y organizar datos relacionados con la intensidad solar y la sombra? - ¿Cuáles son las diferencias significativas entre el método propuesto y otros servicios globales existentes? Preguntas relacionadas con casos de uso: - ¿Cuáles son los casos de uso de REDSS? - ¿Cuáles son los beneficios de REDSS para expertos y público en general? Para darle una forma concreta a la contribución y el enfoque propuesto, se ha desarrollado un prototipo denominado Energy2People basado en principios de Inteligencia de Negocio que no sólo proporciona datos de localización avanzada sino que es una base sobre la que para desarrollar futuros productos comerciales. En su conformación actual, esta herramienta ayuda a descubrir y representar las relaciones de datos clave en el sector de las energías renovables y, permite descubrir al público en general relaciones entre los datos en casos donde no era evidente. Esencialmente, el enfoque propuesto conduce a un aumento en el rendimiento de gestión y visualización de datos. Las principales aportaciones de esta tesis pueden resumirse como siguen: - En primer lugar, esta tesis hace una revisión de varios modelos de sol-sombra de código abierto y cerrado para identificar el alcance de la necesidad de modelos de decisión y de su soporte efectivo. Además, proporciona información detallada sobre fuentes de información gratuita relacionada con datos de radiación solar. - En segundo lugar, se plantea un armazón conceptual para el desarrollo de modelos geográficos de bajo coste. Como ejemplo de la aplicación de esta aproximación se ha desarrollado un modelo de bajo coste de ciudad virtual 3D utilizando datos catastrales públicamente disponibles vía servicios Web. - En tercer lugar, este trabajo propone el uso de REDSS al problema de la toma de decisiones en el campo de la energía solar. Este modelo también cuenta con otros puntos distinguibles como los enfoques de co-creación y Mix-and-match. - En cuarto lugar, esta tesis identifica varios escenarios de aplicaciones reales y varios tipos de actores que deberían salir beneficiados por la aplicación de esta estrategia. - Por último, esta tesis presenta el prototipo "Enery2People" desarrollado para explorar datos de localización de la radiación solar y eventos temporales que sirve como ejemplo práctico de la aproximación planteada en esta tesis. Para hacer más claro el potencial del enfoque propuesto, este prototipo es comparado con otros Atlas Internacionales de la energía renovable

    The role of volunteered geographic information in land administration systems in developing countries

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    PhD ThesisDeveloping countries, especially in Africa are faced with a lack of formally registered land. Available limited records are outdated, inaccurate and unreliable, which makes it a challenge to properly administer and manage land and its resources. Moreover, limited maintenance budgets prevalent in these countries make it difficult for organizations to conduct regular systematic updates of geographic information. Despite these challenges, geographic information still forms a major component for effective land administration. For a land administration system (LAS) to remain useful, it must reflect realities on the ground, and this can only be achieved if land information is reported regularly. However, if changes in land are not captured in properly administered land registers, LAS lose societal relevance and are eventually replaced by informal systems. Volunteered Geographic Information (VGI) can address these LAS challenges by providing timely, affordable, up-to-date, flexible, and fit for purpose (FFP) land information to support the limited current systems. Nonetheless, the involvement of volunteers, who in most cases are untrained or non-experts in handling geographic information, implies that VGI can be of varying quality. Thus, VGI is characterised by unstructured, heterogeneous, unreliable data which makes data integration for value-added purposes difficult to effect. These quality challenges can make land authorities reluctant to incorporate the contributed datasets into their official databases. This research has developed an innovative approach for establishing the quality and credibility of VGI such that it can be considered in LAS on an FFP basis. However, verifying volunteer efforts can be difficult without reference to ground truth, which is prevalent in many developing countries. Therefore, a novel Trust and Reputation Modelling (TRM) methodology is proposed as a suitable technique to effect such VGI validation. TRM relies on a view that the public can police themselves in establishing ‘proxy’ measures of VGI quality and credibility of volunteers, thus facilitating VGI to be used on an FFP basis in LAS. The output of this research is a conceptual participatory framework for an FFP land administration based on VGI. The framework outlines major aspects (social, legal, technical, and institutional) necessary for establishing a participatory FFP LAS in developing countries.University of Botswan

    Land information systems : an overview and outline of software requirements

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    This thesis looks at some aspects of land information systems. The introduction gives the rationale for this study, and the second chapter outlines the development of land information systems with particular reference to the cadastre. In the third chapter the software requirements for the development of land information systems are considered. Programming language and databases are discussed. The fouth chapter deals with the organisation and hardware needed for a land information system. Finally, in the fifth chapter some of the algorithms used in land information systems are presented. Four appendices cover the programmes which were developed in the course of this study, the software specification for an operational system, an example of LIS-related data in a large organisation, and the syntax of Modula-2, the programming language used for the examples

    From buildings to cities: techniques for the multi-scale analysis of urban form and function

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    The built environment is a significant factor in many urban processes, yet direct measures of built form are seldom used in geographical studies. Representation and analysis of urban form and function could provide new insights and improve the evidence base for research. So far progress has been slow due to limited data availability, computational demands, and a lack of methods to integrate built environment data with aggregate geographical analysis. Spatial data and computational improvements are overcoming some of these problems, but there remains a need for techniques to process and aggregate urban form data. Here we develop a Built Environment Model of urban function and dwelling type classifications for Greater London, based on detailed topographic and address-based data (sourced from Ordnance Survey MasterMap). The multi-scale approach allows the Built Environment Model to be viewed at fine-scales for local planning contexts, and at city-wide scales for aggregate geographical analysis, allowing an improved understanding of urban processes. This flexibility is illustrated in the two examples, that of urban function and residential type analysis, where both local-scale urban clustering and city-wide trends in density and agglomeration are shown. While we demonstrate the multi-scale Built Environment Model to be a viable approach, a number of accuracy issues are identified, including the limitations of 2D data, inaccuracies in commercial function data and problems with temporal attribution. These limitations currently restrict the more advanced applications of the Built Environment Model

    Environmental Assessment of Soil for Monitoring Volume I: Indicators & Criteria

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    The ENVASSO Project (Contract 022713) was funded 2006-8, under the European Commission 6th Framework Programme of Research, with the objective of defining and documenting a soil monitoring system appropriate for soil protection at continental level. The ENVASSO Consortium, comprising 37 partners drawn from 25 EU Member States, reviewed soil indicators, identified existing soil inventories and monitoring programmes in the Member States, designed and programmed a database management system to capture, store and supply soil profile data, and drafted procedures and protocols appropriate for inclusion in a European soil monitoring network of sites that are geo-referenced and at which a qualified sampling process is or could be conducted. Volume I, one of six describing the results of the ENVASSO Project, identifies 290 potential indicators relating to 188 key issues for the following nine threats to soil: erosion, organic matter decline, contamination, sealing, compaction, loss of biodiversity, salinisation, landslides and desertification. Sixty candidate indicators that address 27 key issues, covering all these threats, were selected on the basis of their thematic relevance, policy relevance and data availability. Baseline and threshold values are presented and detailed Fact Sheets describe three priority indicators for each soil threat.JRC.DDG.H.7-Land management and natural hazard

    CLOUD-BASED SOLUTIONS IMPROVING TRANSPARENCY, OPENNESS AND EFFICIENCY OF OPEN GOVERNMENT DATA

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    A central pillar of open government programs is the disclosure of data held by public agencies using Information and Communication Technologies (ICT). This disclosure relies on the creation of open data portals (e.g. Data.gov) and has subsequently been associated with the expression Open Government Data (OGD). The overall goal of these governmental initiatives is not limited to enhance transparency of public sectors but aims to raise awareness of how released data can be put to use in order to enable the creation of new products and services by private sectors. Despite the usage of technological platforms to facilitate access to government data, open data portals continue to be organized in order to serve the goals of public agencies without opening the doors to public accountability, information transparency, public scrutiny, etc. This thesis considers the basic aspects of OGD including the definition of technical models for organizing such complex contexts, the identification of techniques for combining data from several portals and the proposal of user interfaces that focus on citizen-centred usability. In order to deal with the above issues, this thesis presents a holistic approach to OGD that aims to go beyond problems inherent their simple disclosure by providing a tentative answer to the following questions: 1) To what extent do the OGD-based applications contribute towards the creation of innovative, value-added services? 2) What technical solutions could increase the strength of this contribution? 3) Can Web 2.0 and Cloud technologies favour the development of OGD apps? 4) How should be designed a common framework for developing OGD apps that rely on multiple OGD portals and external web resources? In particular, this thesis is focused on devising computational environments that leverage the content of OGD portals (supporting the initial phase of data disclosure) for the creation of new services that add value to the original data. The thesis is organized as follows. In order to offer a general view about OGD, some important aspects about open data initiatives are presented including their state of art, the existing approaches for publishing and consuming OGD across web resources, and the factors shaping the value generated through government data portals. Then, an architectural framework is proposed that gathers OGD from multiple sites and supports the development of cloud-based apps that leverage these data according to potentially different exploitation roots ranging from traditional business to specialized supports for citizens. The proposed framework is validated by two cloud-based apps, namely ODMap (Open Data Mapping) and NESSIE (A Network-based Environment Supporting Spatial Information Exploration). In particular, ODMap supports citizens in searching and accessing OGD from several web sites. NESSIE organizes data captured from real estate agencies and public agencies (i.e. municipalities, cadastral offices and chambers of commerce) in order to provide citizens with a geographic representation of real estate offers and relevant statistics about the price trend.A central pillar of open government programs is the disclosure of data held by public agencies using Information and Communication Technologies (ICT). This disclosure relies on the creation of open data portals (e.g. Data.gov) and has subsequently been associated with the expression Open Government Data (OGD). The overall goal of these governmental initiatives is not limited to enhance transparency of public sectors but aims to raise awareness of how released data can be put to use in order to enable the creation of new products and services by private sectors. Despite the usage of technological platforms to facilitate access to government data, open data portals continue to be organized in order to serve the goals of public agencies without opening the doors to public accountability, information transparency, public scrutiny, etc. This thesis considers the basic aspects of OGD including the definition of technical models for organizing such complex contexts, the identification of techniques for combining data from several portals and the proposal of user interfaces that focus on citizen-centred usability. In order to deal with the above issues, this thesis presents a holistic approach to OGD that aims to go beyond problems inherent their simple disclosure by providing a tentative answer to the following questions: 1) To what extent do the OGD-based applications contribute towards the creation of innovative, value-added services? 2) What technical solutions could increase the strength of this contribution? 3) Can Web 2.0 and Cloud technologies favour the development of OGD apps? 4) How should be designed a common framework for developing OGD apps that rely on multiple OGD portals and external web resources? In particular, this thesis is focused on devising computational environments that leverage the content of OGD portals (supporting the initial phase of data disclosure) for the creation of new services that add value to the original data. The thesis is organized as follows. In order to offer a general view about OGD, some important aspects about open data initiatives are presented including their state of art, the existing approaches for publishing and consuming OGD across web resources, and the factors shaping the value generated through government data portals. Then, an architectural framework is proposed that gathers OGD from multiple sites and supports the development of cloud-based apps that leverage these data according to potentially different exploitation roots ranging from traditional business to specialized supports for citizens. The proposed framework is validated by two cloud-based apps, namely ODMap (Open Data Mapping) and NESSIE (A Network-based Environment Supporting Spatial Information Exploration). In particular, ODMap supports citizens in searching and accessing OGD from several web sites. NESSIE organizes data captured from real estate agencies and public agencies (i.e. municipalities, cadastral offices and chambers of commerce) in order to provide citizens with a geographic representation of real estate offers and relevant statistics about the price trend
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