12 e 13 de junho de 2000, Centro Anhembi, São Paulo, SP
Several improvements are noticed on Geographic Information Systems, motivated by the general trends in information technologies, expanding their potential uses to domain experts. In that sense, GIS should consider the user's familiarity with Cartography and its traditional way of representing natural phenomena. Understanding the construction and interpretation of maps as communication activities, this paper evaluates the expression power of GIS relatively to their cartographic elements, based on a Semiotic approach. Results obtained from the comparison between Cartographic and GIS semiotic systems show a great difference in the potential for communication for each one of the domains.
Modelagem Geométrica 3D e Análise Espacial de Sistemas Cársticos com o uso de OpenGL e SQL
José Antonio Ferrari, Alain Mangin
This paper describes a system developed for geometrical modeling and analysis of karst systems. The program calculates the closure of loops in cave surveys by least square method, and provides the means to obtain query derived maps of the underground system. The software integrates OpenGL and Microsoft Jet database engine technologies to produce 3D visualization of cave passages and digital elevation models linked with database. Some examples produced with the system are presented.
Extração Semi-Automática de Rodovias Usando Programação Dinâmica
Aluir Porfírio Dal Poz, Peggy Agouris
This paper presents a semi-automatic road extraction approach from aerial and satellite images for GIS (Geographic Information System) road network updating and capture. Basically, a generic road model is formulated using six basic road properties, which is solved sequentially by a dynamic programming algorithm. A few seed points describing coarsely the road need to be provided by the operator. The mathematical fundamentals of the methods and experimental results are presented and discussed in this paper.
Extração de Dados em Sistemas de Informações Ambientais: Arquitetura e Esquema de Metadados
Hélio Alvaro de Mello Perez, Ana Maria de Carvalho Moura, Astério Kiyoshi Tanaka
Environmental information is very important for the creation of environmental protection strategies, representing one of the greatest worries of most public organizations and societies in the world. Characterized by its heterogeneous and distributed nature, this kind of information needs to be integrated and changed into useful information, originating the so-called Environmental Information Systems (EIS). One of the greatest difficulties in constructing an EIS concerns, besides the huge amount of available data, the lack of a storage standard format, turning out its use and integration to be very difficult. Besides, the most specific and well-known metadata standards used for cataloguing environmental data still present a low power level for representing the structural part of data repositories. This paper presents a three-layer architecture to support the access and extraction processes of environmental data captured from heterogeneous and distributed repositories, and a metamodel based on metadata to enable the structure mapping of these data into an intermediate level, allowing users to build their programs to access the information directly, without changing the original storage location nor the data structure or data formats.
Fatores Determinantes de Desempenho de Métodos de Acesso Multidimensionais
Ricardo Rodrigues Ciferri, Ana Carolina Salgado
Spatial data base systems (SDBSs) deal with data that are special in nature and size. Thus, the technologies developed for conventional data base systems such as physical design, access methods, query optimizers and languages, have to be modified in order to satisfy the needs of a SDBS. These modifications, embedded in several SDBSs, or being proposed by research projects, need to be evaluated. Our research focuses specifically multidimensional access methods (MAMs), which are very important structures used to diminish the execution time of search operations in a SDBS. In this paper, we discuss two important factors that affect the performance of MAMs: degree of overlap between non-zero size data objects and data selectivity.
Segmentação e Classificação Supervisionada para Identificar Pastagens Degradadas
Lucimar Moreira, Eduardo Delgado Assad
One of the major environmental issues in the Brazilian Cerrado region is the identification of the levels of degradation in the cultivated pastures. About 50 million hectares of Cerrado is currently covered by cultivated pastures, with different degradation levels. This paper assesses the performance of supervised classification per region for identifying different degradation levels in cultivated pastures. The study area is located in the córrego Lamarão Watershed , Federal District. The satellite images were processed by using the SPRING/INPE Geographical Information System. We were able to identify five levels of cultivated pasture degradation.
Aplicação de Raciocínio Baseado em Casos a Sistemas de Apoio à Decisão Ambiental
Daniel dos Santos Kaster, Claudia Bauzer Medeiros, Heloísa Vieira da Rocha
One area which demands decision support applications is environmental planning. Because of the inherent complexity of environmental systems, standard Decision Support Systems (DSS) do not supply enough functionalities to deal with the related issues. Spatial DSS focused on environmental domains extend traditional DSS by providing adequate tools for environmental analysis and problem solving. This paper describes an environmental SDSS under development at IC-UNICAMP which combines scientific workflows, Case-Based Reasoning (CBR) and Geographical Information Systems (GIS). This system is based on two components: (1) an existing SDSS named WOODSS (WOrkflOw-based spatial Decision Support System), developed at IC-UNICAMP, which interacts with a GIS and uses scientific workflows to document environmental models; and (2) an intelligent model retrieval mechanism based on CBR.
Ontologias e Interoperabilidade Semântica entre SIGs
Frederico Fonseca, Max Egenhofer, Karla A. V. Borges
The complexity and richness of geospatial data and the difficulty of their representation create specific problems for geographic information systems interoperability. This paper proposes the creation of software components from ontologies as a way to integrate geographic information. These software components are derived from ontologies using an object-oriented mapping. The translation of ontologies into active information system components leads to ontology-driven geographic information systems. The approach introduced by this work enables the use of the architecture by users developing new applications and by GIS database designers. The results presented here answer many questions presented in past works that dealt with the quest for a new GIS. The proposed architecture is up to date with requirements of modern information systems that should provide interoperability and move from managing data and information to managing knowledge.
Extensões ao Modelo OMT-G para Produção de Esquemas Dinâmicos e de Apresentação
Clodoveu A. Davis Jr., Alberto H. F. Laender
A construção de um esquema conceitual é parte fundamental do processo de desenvolvimento de aplicações. No caso das aplicações geográficas, no entanto, é necessário levar em consideração outros fatores, especialmente relativos à representação dos objetos espaciais. Sem a definição da representação, torna-se difí-cil a especificação dos relacionamentos espaciais e topológicos entre os objetos. Reunindo elementos conceitu-ais e de representação, aplicações geográficas podem ser modeladas estaticamente usando o modelo OMT-G. Este artigo propõe extensões ao modelo OMT-G, no sentido de permitir a especificação de transformações entre representações, por meio de um esquema dinâmico. Também são propostas extensões para a especifica-ção de diferentes apresentações visuais para cada representação modelada, compondo um esquema de apre-sentações. As extensões propostas permitem que projetos de aplicações geográficas incorporem aspectos de múltiplas representações e múltiplas apresentações, viabilizando assim o compartilhamento do banco de dados geográfico entre diferentes grupos de usuários.
A Comparison among Different Synchronized Tree Traversal Algorithms for Spatial Joins
Sandro Danilo Gatti, Geovane Cayres Magalhães
Spatial join techniques for spatial access methods where analysed, considering factors such as buffer pool size, page size and intermediate join indexes ordering criteria. This analysis was based on real data, taken from GIS applications for utilities. Results of this work assess the way those factors affect spatial join performance and can be used for tuning the algorithms.
Towards a Unified Framework for Geographical Data Models
Gilberto Câmara, Antônio Miguel Vieira Monteiro, João Argemiro Paiva, Jonas Gomes, Luiz Velho
This paper describes a unified framework for the problems of modelling and processing geographical entities. We propose a general definition of geographical objects, and show that the different types of geographical data can be expressed as particular cases of this definition. Furthermore, we present a taxonomy for the various types of GIS operations, defined in terms of the properties of this definition. Our goal is to argue that GIS data types and operations can be defined based on a single formal notion, which encapsulates the GIS concepts of both fields and objects, with important consequences for system and interface design, interoperabilty issues and language proposal.
Trading e Agentes em Sistemas de Informações Geográficas Distribuídos
Sônia Virgínia Alves França, Carlos André Guimarães Ferraz
This paper describes a model that allows heterogeneous Geographic Information Systems, distributed over wide area networks to communicate with each other, interoperating data and services. The model is based on distributed objects and agents technologies and on the OGIS standard, defining the concepts of GISTrader and Geoagents as components that enable interoperability between geoprocessing applications, as well as contribute to good performance when such applications are distributed over heterogeneous and wide area networks.
On the Use of Indicator Simulation for Numerical Predictions with Uncertainty Assessment
Carlos Alberto Felgueiras, Suzana Druck Fuks, Antônio Miguel Vieira Monteiro, Eduardo Celso Gerbi Camargo
Raster representations of thematic and numerical spatial attributes are very common in a GIS environment for computational simulation and analysis of spatial processes. This paper addresses the problem of predictions with uncertainty assessment for GIS raster representations created from a set of sample points of spatial attributes. The realizations of a stochastic simulation inference process, over numerical attribute samples, are used in order to infer the attribute values and related uncertainties at non-sampled spatial locations. A case study, using elevation sample data, is presented to illustrate the concepts used in this work.
Servlets e COM para Visualização de Dados Geográficos na Web
Arlindo Cardarett Vianna, Anselmo Cardoso de Paiva, Marcelo Gattass
This paper presents an ongoing study of the viability of using Java servlets and COM components for developing dynamic web sites of geographic data. The maps are presented using the TWF (TeCGraf Web Format). The used technologies are discussed and the context in which they are useful is described.
TerraLib: Technology in Support of GIS Innovation
Gilberto Câmara, Ricardo Cartaxo Modesto de Souza, Bianca Maria Pedrosa, Lúbia Vinhas, Antônio Miguel Vieira Monteiro, João Argemiro Paiva, Marcelo Tilio de Carvalho, Marcelo Gattass
This work describes the development of a new GIS library (called TerraLib), that is aimed at providing a rich and powerful environment for the development of GIScience research. The motivation for this proposal is the current lack of either public or commercial GIS libraries that cater for the diversity of GIS data and algorithms, especially when viewed upon the latest advances in geographical information science. TerraLib is open source software, allowing a collaborative environment and its use for the development of multiple GIS tools.
Uma Metodologia para Geração de Modelos de Elevação a partir de Curvas de Nível
Roberto de Beauclair Seixas, Luiz Henrique de Figueiredo, Claudio Antonio da Silva, Paulo Cezar Pinto Carvalho
Modelos digitais de terrenos baseados em elevação são muito utilizados e possuem inúmeras aplicações. Portanto, técnicas que possibilitem a conversão de outras representações para modelos de elevação são extremamente importantes. Neste trabalho, apresentamos uma metodologia para geração automática de modelos de elevação a partir de curvas de nível, com uma resolução refinada de acordo com a necessidade do usuário. Além disso é apresentada uma breve descrição dos problemas envolvidos nesta metodologia.
Arquiteturas Cliente-Servidor para Bibliotecas Geográficas Digitais
José Roberto Osses, João Argemiro de Carvalho Paiva, Gilberto Câmara
This work describes the development of a client-server application for dissemination of geographical data on the Internet. The authors describes a strategy that relies on use of the conceptual schema of the geographical database as a means for data selection and for establishing a compromise between client and server. The resulting system has acceptable performance and indicates a possible client-server solution for geographical digital libraries.
Exchange Mechanism for Global Mapping
Teresa Cristina Veiga
This paper describes findings and results of the research realized for the Global Mapping Project, with the cooperation of Geographic Survey Institute (GSI), Japan, in order to set the procedures for converting cartographic digital data in vector format, produced at IBGE, at 1 to 1 million scale, to Global Map specifications.