2,012 research outputs found

    An Egocentric Spatial Data Model for Intelligent Mobile Geographic Information Systems

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    Individuals in unknown locations, such as utility workers in the field, soldiers on a mission, or sightseeing tourists, share the need for an answer to two basic questions: Where am I? and What is in front of me?Because such information is not readily available in foreign locations, aids in the form of paper maps or mobile GISs, which give individuals an all-inclusive view of the environment, are often used. This panoptic view may hinder the positioning and orienteering process, since people perceive their surroundings perspectively from their current position. In this thesis, I describe a novel framework that resolves this problem by applying sensors that gather the individual\u27s spatial frame of reference. This spatial frame of reference, in combination with an egocentric spatial data model enables an injective mapping between the real world and the data frame of reference, hence, alleviating the individual\u27s cognitive workload. Furthermore, our egocentric spatial data model allows intelligent mobile Geographic Information Systems to capture the notions of here and there, and, consequently, provides insight into the individual\u27s surroundings. Finally, our framework, in conjunction with the context given by the task to be performed, enables intelligent mobile Geographic Information Systems to implicitly answer questions with respect to where, what, and how

    Методы создания электронных атласов устойчивого развития регионов в сети Internet

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    Предложен новый подход к автоматическому поиску данных для электронных атласов устойчивого развития регионов, базирующийся на методах Data Mining и позволяющий находить в сети Интернет релевантные данные с использованием эталонных Web-документов. Разработана технология проектирования агентно-ориентированных интерфейсов для ГИС, основанная на применении мультиагентных систем и позволяющая автоматизировать наполнение и обновление баз данных электронных геоинформационных атласов.Запропоновано новий підхід до автоматичного пошуку даних для електронних атласів сталого розвитку регіонів, що базується на методах Data Mining і дозволяє знаходити в мережі Інтернет релевантні дані з використанням еталонних Web-документів. Розроблено технологію проектування агентно-орієнтованих інтерфейсів для ГІС, що базується на застосуванні мультиагентних систем і дозволяє автоматизувати наповнення і оновлення баз даних електронних геоінформаційних атласів.A new approach to automated data retrieval for electronic atlases of sustainable development of regions is presented. It is based on the Data Mining methods and allows to find relevant data in the Internet using reference Web-documents. The technology of agent-oriented interfaces designing for GIS is created. It is based on multi-agent systems application and allows automated filling and updating databases of electronic geoinformation atlases

    Orchestrating standard web services to produce thematic maps in a geoportal of a spatial data infrastructure

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    Cartography is the science and art of making maps and thematic cartography is a subsection that deals with the production of thematic maps. A thematic map portrays the distribution of features, incidents or classifications related to a specific topic. With the rapidly increasing volumes of data, thematic maps allow users to efficiently analyse data and identify trends quicker. A spatial data infrastructure (SDI) focuses on making data available and ensures data interoperability through a geoportal and associated web services for discovery, display, editing, and analysis. Implementations of web service standards by the Open Geospatial Consortium (OGC), and the ISO/TC211, Geographic information/Geomatics enable the display, query and custom visualisation of spatial data in a geoportal. In the past, sophisticated cartographic methods have been mainly available on desktop applications, but with the advances in web mapping technology these methods have become increasingly popular on the Web. Currently, producing thematic maps using web services is a manual process that requires quite a lot of custom programming. The orchestrations of standard web services automate the process to produce thematic maps in a geoportal. It is preferable to use standard web services as opposed to customised programming; the standards provide flexibility, interoperability, and standard protocols, to name a few benefits. The goal of this research was to determine how standard OGC web services could be orchestrated to produce thematic maps within the geoportal of an SDI. To achieve this goal, an orchestrated thematic web service, named ThematicWS, was constructed from existing implementations of individual standard OGC web services, which are monolithic and interchangeable. The thematic cartographic process for producing choropleth and proportional symbol maps was investigated to model the process and obtain a set of steps. Experiments were performed to determine which existing web service standards could be used in the process. ThematicWS was developed using existing implementations of the following standards: WFS to retrieve the attribute data, WPS for the wrapping of custom functionalities (statistical processing and SLD generation), and a WMS to produce the thematic map image. The 52° North and ZOO project frameworks’ orchestration capabilities were evaluated for to determine the suitability for producing thematic maps. The evaluation showed that orchestration is possible in both frameworks. However, there are limitations in both frameworks for automatic orchestration such as the lack of semantic information and poor usability of the framework. The use of WPS services to wrap custom functionalities and to provide a standard interface has proved to be useful for the orchestration of standard web services. ThematicWS was successfully implemented based on standard web service implementations using both workflow scripting and workflow modelling. The orchestrated ThematicWS can be called and consumed by a geoportal of an SDI to produce thematic maps according to user defined parameters.Dissertation (MSc)--University of Pretoria, 2013.Geography, Geoinformatics and MeteorologyUnrestricte

    A Technical Solution to Allow Off-line Mobile Map Querying of Discrete and Continuous Geographic Attribute Data

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    In this article, a technique towards the generation of hybrid raster-attributes map for use in mobile devices is described. Our solution is based on coding the map attributes within an image using RGB values. The designed coding method enables the simultaneous storage of discrete thematic attributes and continuous quantitative attributes. This approach offers a wide range of possible uses. Small memory storage requirements and the simplicity of the software enable this coding method to be used efficiently in mobile devices without Internet connection. This article describes the basic fundamentals of the coding technique, as well as the operation and limitations regarding the volume of information. Two specific applications are presented: a topographic map used for recreational activities, and a visitor map of a university campus.Palomar-Vázquez, J.; Pardo Pascual, JE.; Sebastiá Tarín, L.; Recio Recio, JA. (2012). A Technical Solution to Allow Off-line Mobile Map Querying of Discrete and Continuous Geographic Attribute Data. Cartographic Journal. 49(2):143-152. doi:10.1179/1743277411Y.0000000029S14315249

    Актуализация баз данных геоинформационных атласов в автоматизированном режиме

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    This study represents a first attempt at applying a fuzzy inference system (FIS) and an adaptive neuro-fuzzy inference system (ANFIS) to the field of aquatic biomonitoring for classification of the dosage and time of benzo[a]pyrene (BaP) injection through selected biomarkers in African catfish (Clarias gariepinus). Fish were injected either intramuscularly (i.m.) or intraperitoneally (i.p.) with BaP. Hepatic glutathione S-transferase (GST) activities, relative visceral fat weights (LSI), and four biliary fluorescent aromatic compounds (FACs) concentrations were used as the inputs in the modeling study. Contradictory rules in FIS and ANFIS models appeared after conversion of bioassay results into human language (rule-based system). A "data trimming" approach was proposed to eliminate the conflicts prior to fuzzification. However, the model produced was relevant only to relatively low exposures to BaP, especially through the i.m. route of exposure. Furthermore, sensitivity analysis was unable to raise the classification rate to an acceptable level. In conclusion, FIS and ANFIS models have limited applications in the field of fish biomarker studies

    A quality-aware spatial data warehouse for querying hydroecological data

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    International audienceAddressing data quality issues in information systems remains a challenging task. Many approaches only tackle this issue at the extract, transform and load steps. Here we define a comprehensive method to gain greater insight into data quality characteristics within data warehouse. Our novel architecture was implemented for an hydroecological case study where massive French watercourse sampling data are collected. The method models and makes effective use of spatial, thematic and temporal accuracy, consistency and completeness for multidimensional data in order to offer analysts a âdata qualityâ oriented framework. The results obtained in experiments carried out on the Saône River dataset demonstrated the relevance of our approac

    Geomatics for Mobility Management. A comprehensive database model for Mobility Management

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    In urban and metropolitan context, Traffic Operations Centres (TOCs) use technologies as Geographic Information Systems (GIS) and Intelligent Transport Systems (ITS) to tackling urban mobility issue. Usually in TOCs, various isolated systems are maintained in parallel (stored in different databases), and data comes from different sources: a challenge in transport management is to transfer disparate data into a unified data management system that preserves access to legacy data, allowing multi-thematic analysis. This need of integration between systems is important for a wise policy decisions. This study aims to design a comprehensive and general spatial data model that could allow the integration and visualization of traffic components and measures. The activity is focused on the case study of 5T Agency in Turin, a TOC that manages traffic regulation, public transit fleets and information to users, in the metropolitan area of Turin and Piedmont Region. In particular, the agency has set up during years a wide system of ITS technologies that acquires continuously measures and traffic information, which are used to deploy information services to citizens and public administrations. However, the spatial nature of these data is not fully considered in the daily operational activity, with the result of difficulties in information integration. Indeed the agency lacks of a complete GIS that includes all the management information in an organized spatial and “horizontal” vision. The main research question concerns the integration of different kind of data in a unique GIS spatial data model. Spatial data interoperability is critical and particularly challenging because geographic data definition in legacy database can vary widely: different data format and standards, data inconsistencies, different spatial and temporal granularities, different methods and enforcing rules that relates measures, events and physical infrastructures. The idea is not to replace the existing implemented and efficient system, but to built-up on these systems a GIS that overpass the different software and DBMS platforms and that can demonstrate how a spatial and horizontal vision in tackling urban mobility issues may be useful for policy and strategies decisions. The modelling activity take reference from a transport standards review and results in database general schema, which can be reused by other TOCs in their activities, helping the integration and coordination between different TOCs. The final output of the research is an ArcGIS geodatabase, tailored on 5T data requirements, which enable the customised representation of private traffic elements and measures. Specific custom scripts have been developed to allow the extraction and the temporal aggregation of traffic measures and events. The solution proposed allows the reuse of data and measures for custom purposes, without the need to deeply know the entire ITS environment system. In addition, The proposed ArcGIS geodatabase solution is optimised for limited power-computing environment. A case study has been deepened in order to evaluate the suitability of the database: a confrontation between damages, detected by Emergency Mapping Services (EMS), and Traffic Message Channel traffic events, has been conducted, evaluating the utility of 5T historical information of traffic events of the Piedmont floods of November 2016 for EMS services

    A Comparison of the Classification of Vegetation Characteristics by Spectral Mixture Analysis and Standard Classifiers on Remotely Sensed Imagery within the Siberia Region

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    As an alternative to the traditional method of inferring vegetation cover characteristics from satellite data by classifying each pixel into a specific land cover type based on predefined classification schemes, the Spectral Mixture Analysis (SMA) method is applied to images of the Siberia region. A linear mixture model was applied to determine proportional estimates of land cover for, (a) agriculture and floodplain soils, (b) broadleaf, and (c) conifer classes, in pixels of 30 m resolution Landsat data. In order to evaluate the areal estimates, results were compared with ground truth data, as well as those estimates derived from more sophisticated method of image classification, providing improved estimates of endmember values and subpixel areal estimates of vegetation cover classes than the traditional approach of using predefined classification schemes with discrete numbers of cover types. This technique enables the estimation of proportional land cover type in a single pixel and could potentially serve as a tool for deriving improved estimates of vegetation parameters that are necessary for modeling carbon processes

    Dwelling on ontology - semantic reasoning over topographic maps

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    The thesis builds upon the hypothesis that the spatial arrangement of topographic features, such as buildings, roads and other land cover parcels, indicates how land is used. The aim is to make this kind of high-level semantic information explicit within topographic data. There is an increasing need to share and use data for a wider range of purposes, and to make data more definitive, intelligent and accessible. Unfortunately, we still encounter a gap between low-level data representations and high-level concepts that typify human qualitative spatial reasoning. The thesis adopts an ontological approach to bridge this gap and to derive functional information by using standard reasoning mechanisms offered by logic-based knowledge representation formalisms. It formulates a framework for the processes involved in interpreting land use information from topographic maps. Land use is a high-level abstract concept, but it is also an observable fact intimately tied to geography. By decomposing this relationship, the thesis correlates a one-to-one mapping between high-level conceptualisations established from human knowledge and real world entities represented in the data. Based on a middle-out approach, it develops a conceptual model that incrementally links different levels of detail, and thereby derives coarser, more meaningful descriptions from more detailed ones. The thesis verifies its proposed ideas by implementing an ontology describing the land use ‘residential area’ in the ontology editor Protégé. By asserting knowledge about high-level concepts such as types of dwellings, urban blocks and residential districts as well as individuals that link directly to topographic features stored in the database, the reasoner successfully infers instances of the defined classes. Despite current technological limitations, ontologies are a promising way forward in the manner we handle and integrate geographic data, especially with respect to how humans conceptualise geographic space
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