Claudia Bauzer Medeiros

Databases for GIS

The problems of discussing Geographic Information Systems GIS, for short begin with defining this term. There are countless definitions for GIS, each based on the type of user and application domain [43]. The more general definition [24] would be “a digital information system whose records are somehow geographically referenced”. For more precise definitions, one may emphasize their functional capabilities (e.g., that GIS capture and process spatial data) or the applications supported (linking the definition to the type of problem solved). Others stress the fact that GIS are ultimately tools to be used for decision support. Last but not least, a GIS is database-dependent (“a database system that supports management of spatial data”). In the database community, GIS are primarily associated with spatial databases, and therefore a large amount of the research effort in databases for GIS is related to spatial structures and access methods (see section 7). Research has also considered data modelling [69, 25, 561, query language constructs and optimization (see sections 5 and 6), temporal data support [64, 38, 541, and experimenting with existing DBMS to manage georeferenced data (section 8). Database specialists often ignore many concerns that underly endusers’ applications, such as data accuracy evaluation, feature generalization, fuzziness of geometric boundaries or need for versatile data analysis tools.

POESIA: An ontological workflow approach for composing Web services in agriculture

Abstract.This paper describes the POESIA approach to systematic composition of Web services. This pragmatic approach is strongly centered in the use of domain-specific multidimensional ontologies. Inspired by applications needs and founded on ontologies, workflows, and activity models, POESIA provides well-defined operations (aggregation, specialization, and instantiation) to support the composition of Web services. POESIA complements current proposals for Web services definition and composition by providing a higher degree of abstraction with verifiable consistency properties. We illustrate the POESIA approach using a concrete application scenario in agroenvironmental planning.

Visual structures for image browsing

Content-Based Image Retrieval (CBIR) presents several challenges and has been subject to extensive research from many domains, such as image processing or database systems. Database researchers are concerned with indexing and querying, whereas image processing experts worry about extracting appropriate image descriptors. Comparatively little work has been done on designing user interfaces for CBIR systems. This, in turn, has a profound effect on these systems since the concept of image similarity is strongly influenced by user perception. This paper describes an initial effort to fill this gap, combining recent research in CBIR and Information Visualization, studied from a Human-Computer Interface perspective. It presents two visualization techniques based on Spiral and Concentric Rings implemented in a CBIR system to explore query results. The approach is centered on keeping user focus on both the query image, and the most similar retrieved images. Experiments conducted so far suggest that the proposed visualization strategies improves system usability.

Discovering geographic locations in web pages using urban addresses

This paper presents an approach that helps to discover geographic locations from the recognition, extraction, and geocoding of urban addresses found in Web pages. Experiments that evaluate the presence and incidence of urban addresses in Web pages are described. Experimental results, based on a collection of over 4 million documents from the Brazilian Web, show the feasibility and effectiveness of the proposed method.

WOODSS — a spatial decision support system based on workflows

Abstract Environmental planning takes advantage of geographic information systems (GIS) to manage geographic data. GIS are, however, tools which require a great deal of training and programming expertise and, furthermore, have little support for decision makers during their planning activities. This paper presents WOrkflOw-based spatial Decision Support System ( woodss ) — a software developed at the University of Campinas, Brazil, to be used in conjunction with a GIS in order to provide spatial decision support involving environmental data. woodss was implemented on top of a commercial GIS and tested in the context of agri-environmental planning activities. woodss is centered on dynamically capturing user interactions with a GIS in real time and documenting them by means of scientific workflows. It keeps track of decision procedures, models applied and the choice of parameters in running these models. woodss s workflows can be updated on the fly, allowing testing and comparison of alternative planning strategies. They can, furthermore, be used as building blocks for the construction of complex decision procedures, supporting a divide-and-conquer problem solution style. These workflows interact directly with the GIS, sparing environmental planners and decision makers the burden of low-level programming.

An Environment for Modeling and Design of Geographic Applications

This paper presents UAPÉ—a computational environment for modeling and designing environmental geographic applications. UAPÉ is aimed at end-users who are experts in their application domain, but who do not have adequate background in software engineering or database design, and thus are unable to take full advantage of available GIS tools. Its goal is to reduce the impedance between the end-users’ view of the world and its implementation in Geographic Information Systems. The environment has been designed and implemented so that it can be considered as an auxiliary layer to be coupled to a GIS. The major features of this layer are: it has an open architecture, being independent of a specific GIS, so that it can be coupled to different systems; it allows the user to deal only with the conceptual view of the geographic reality, abstracting the implementation details; it supports a geographic application design methodology, fully integrated with a high-level semantic data model, so there is no impedance mismatch between application design and data modeling.

Object Integrity Using Rules

Integrity maintenance in object-oriented systems has so far received little attention. This paper is an attempt to fill this gap. It describes a mechanism for maintaining integrity in an object-oriented database, implemented for the O2 system, and which uses the production rule approach to constraint maintenance. Object integrity is ensured by objects themselves — the rules which are activated when selected events take place. The approach presented is original, in the sense that it takes full advantage of the object-oriented paradigm, considering constraints as first-class citizens which can be inherited, and defined independently of any application. Furthermore, we support maintenance of not only static but also some types of dynamic constraints, as well as constraints on object behavior.

Aondê: An ontology Web service for interoperability across biodiversity applications

Biodiversity research requires associating data about living beings and their habitats, constructing sophisticated models and correlating all kinds of information. Data handled are inherently heterogeneous, being provided by distinct (and distributed) research groups, which collect these data using different vocabularies, assumptions, methodologies and goals, and under varying spatio-temporal frames. Ontologies are being adopted as one of the means to alleviate these heterogeneity problems, thus helping cooperation among researchers. While ontology toolkits offer a wide range of operations, they are self-contained and cannot be accessed by external applications. Thus, the many proposals for adopting ontologies to enhance interoperability in application development are either based on the use of ontology servers or of ontology frameworks. The latter support many functions, but impose application recoding whenever ontologies change, whereas the first supports ontology evolution, but for a limited set of functions. This paper presents Aonde-a Web service geared towards the biodiversity domain that combines the advantages of frameworks and servers, supporting ontology sharing and management on the Web. By clearly separating storage concerns from semantic issues, the service provides independence between ontology evolution and the applications that need them. The service provides a wide range of basic operations to create, store, manage, analyze and integrate multiple ontologies. These operations can be repeatedly invoked by client applications to construct more complex manipulations. Aonde has been validated for real biodiversity case studies.

A digital library framework for biodiversity information systems

Biodiversity Information Systems (BISs) involve all kinds of heterogeneous data, which include ecological and geographical features. However, available information systems offer very limited support for managing these kinds of data in an integrated fashion. Furthermore, such systems do not fully support image content (e.g., photos of landscapes or living organisms) management, a requirement of many BIS end-users. In order to meet their needs, these users—e.g., biologists, environmental experts—often have to alternate between separate biodiversity and image information systems to combine information extracted from them. This hampers the addition of new data sources, as well as cooperation among scientists. The approach provided in this paper to meet these issues is based on taking advantage of advances in digital library innovations to integrate networked collections of heterogeneous data. It focuses on creating the basis for a next-generation BIS, combining new techniques of content-based image retrieval and database query processing mechanisms. This paper shows the use of this component-based architecture to support the creation of two tailored BIS systems dealing with fish specimen identification using search techniques. Experimental results suggest that this new approach improves the effectiveness of the fish identification process, when compared to the traditional key-based method.

Understanding the implications of view update policies

Database views are traditionally described as unmaterialized queries, which may be coincidentally updatable according to some fixed criteria. One of the problems in updating through views lies in determining whether a given view modification can be correctly translated by the system. To define an updatable view, a view designer must be aware of how an update request in the view will be mapped into updates of the underlying relations. Furthermore, because of side effects, the view designer must also be made aware of the effects of isolated updates back into the view.To address this problem, we present a general algorithm that predicts the effects of arbitrary mapping policies. Given an update policy, this algorithm indicates whether a desired update will, in fact, occur in the view and describes all possible side effects it may have, documenting the conditions under which they occur. The algorithm subsumes the results obtained by other view design tools, and generalizes their use to encompass a larger class of views.