420948
Developments in spatio-temporal query languages
Integrating spatio-temporal data as abstract data types into already existing data models is a promising approach to creating spatio-temporal query languages. In this context, an important new class of queries can be identified which is concerned with developments of spatial objects over time, that is, queries ask especially for changes in spatial relationships. Based on a definition of the notion of spatio-temporal predicate we provide a framework which allows to build more and more complex predicates starting with a small set of elementary ones. These predicates can be well used to characterize developments. We show how these concepts can be realized within the relational data model. In particular, we demonstrate how SQL can be extended to enable the querying of developments.
16884861
Design and implementation of finite resolution crisp and fuzzy spatial objects
Uncertainty management for geometric data is currently an important problem in spatial databases, image databases, and geographic information systems. Spatial entities do not always have homogeneous interiors and sharply defined boundaries but frequently their interiors and boundaries are partially or totally indeterminate and vague. For an important kind of spatial vagueness called spatial fuzziness this paper provides a conceptual and an implementation model of fuzzy spatial objects that also incorporates fuzzy geometric union, intersection, and difference operations as well as fuzzy topological predicates. In particular, this model is not based on Euclidean space and not on an infinite-precision arithmetic which lead to lacking numerical robustness and to topological inconsistency of implementations on a computer; it rests on a finite, discrete geometric domain called grid partition which takes into account finite-precision number systems available in computers. Last but not least, this paper is a contribution to achieve a uniform treatment of vector and raster data.
1455658
Temporal Objects for Spatio-Temporal Data Models and a Comparison of Their Representations
We present anew approach to temporal data modeling based on the very general notion of temporal object. Moreover, we propose the database embedding of temporal objects by means of the abstract data type (ADT) approach. We consider the expressiveness of different temporal database embeddings, and we discuss the combination of temporal and spatial objects into spatio-temporal objects in (relational) databases. We explain various alternatives for spatio-temporal data models and databases and compare their expressiveness.
17108573
Topological Relationships of Complex Points and Complex Regions
Topological relationships between spatial objects have been a focus of research on spatial data handling and reasoning for a long time. Especially as predicates they support the design of suitable query languages for spatial data retrieval and analysis in databases. Unfortunately, they are so far only applicable to simplified abstractions of spatial objects like single points, continuous lines, and simple regions, as they occur in systems like current geographical information systems and spatial database systems. Since these abstractions are usually not sufficient to cope with the complexity of geographic reality, their generalization is needed which especially has influence on the nature, definition, and number of their topological relationships. This paper partially closes this gap and first introduces very general spatial data types for complex points and complex regions. It then defines the corresponding complete sets of mutually exclusive, topological relationships.
12688384
Query-By-Trace: Visual Predicate Specification in Spatio-Temporal Databases
In this paper we propose a visual interface for the specification of predicates to be used in queries on spatio-temporal databases. The approach is based on a visual specification method for temporally changing spatial situations. This extends existing concepts for visual spatial query languages, which are only capable of querying static spatial situations. We outline a preliminary user interface that supports the specification on an intuitive and easily manageable level, and we describe the design of the underlying visual language. The visual notation can be used directly as a visual query interface to spatio-temporal databases, or it can provide predicate specifications that can be integrated into textual query languages leading to heterogeneous languages.
4468582
Genomics Algebra: A New, Integrating Data Model, Language, and Tool for Processing and Querying Genomic Information
The dramatic increase of mostly semi-structured genomic data, their heterogeneity and high variety, and the increasing complexity of biological applications and methods mean that many and very important challenges in biology are now challenges in computing and here especially in databases. In contrast to the many query-driven approaches advocated in the literature, we propose a new integrating approach that is based on two fundamental pillars. The Genomics Algebra provides an extensible set of high-level genomic data types ( GDTs) (e.g., genome, gene, chromosome, protein, nucleotide) together with a comprehensive collection of appropriate genomic functions (e.g., translate, transcribe, decode). The Unifying Database allows us to manage the semi-structured contents of publicly available genomic repositories and to transfer these data into GDT values. These values then serve as arguments of Genomics Algebra operations, which can be embedded into a DBMS query language.
14259556
SearchLight - A Lightweight Search Function for Pervasive Environments
We present a lightweight search function for physical objects in instrumented environments. Objects are tagged with optical markers which are scanned by a steerable camera and projector unit on the ceiling. The same projector can then highlight the objects when given the corresponding marker ID. The process is very robust regarding calibration, and no 3D model of the environment is needed. We discuss the scenario of finding books in a library or office environment and several extensions currently under development.
14244499
Recomindation: New Functions for Augmented Memories
Advances in technological support for augmented personal memories make possible new ways of enhancing the process of product recommendation. Instead of simply analyzing information about a user’s past behavior in order to generate recommendations, a recominder system can additionally supply various types of information from the user’s augmented memory that allows the user to take a more active role in the search for suitable products. We illustrate the paradigm of recomindation with reference to a prototype implementation of the system Specter in a CD shopping scenario and the results of a study with 20 subjects, who found most of the recomindation functionality to constitute a useful enhancement of their shopping experience.
41544599
RDF: Stores - A Lightweight Approach on Managing Shared Knowledge
One of the central ideas of ubiquitous computing research is to create smart real-world artifacts and environments that can spontaneously cooperate in order to enable novel applications that no single device could provide. A critical factor in such applications is the availability of relevant context knowledge, which may be provided by a variety of different sensors, domain models, and applications. Locating, accessing, and preserving such knowledge is not a trivial task, especially in dynamic environments where new knowledge sources and applications may unexpectedly appear while existing ones may vanish. In this paper we present a pragmatic yet powerful approach to manage shared knowledge by introducing a novel concept called RDF:Stores. We will present the general properties of RDF:Stores and describe how they can be implemented using off-the-shelf software components.