173270
A visual language for the evolution of spatial relationships and its translation into a spatio-temporal calculus
Queries about objects that change their spatial attributes over time become particularly interesting when they ask for changes in the spatial relationships between different objects. We propose a visual notation that is able to describe scenarios of changing object relationships. The visual language is based on the idea to analyze two-dimensional traces of moving objects to infer a temporal development of their mutual spatial relationships. We motivate the language design by successively simplifying object traces to their intrinsic properties. The notation can be effectively translated into a calculus of spatio-temporal predicates that formally characterizes the evolution of spatial relationships. We also outline a user interface that supports specifications by menus and a drawing editor. 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.
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.
12250442
A data model and data structures for moving objects databases
We consider spatio-temporal databases supporting spatial objects with continuously changing position and extent, termed moving objects databases. We formally define a data model for such databases that includes complex evolving spatial structures such as line networks or multi-component regions with holes. The data model is given as a collection of data types and operations which can be plugged as attribute types into any DBMS data model (e.g. relational, or object-oriented) to obtain a complete model and query language. A particular novel concept is the sliced representation which represents a temporal development as a set of units, where unit types for spatial and other data types represent certain “simple” functions of time. We also show how the model can be mapped into concrete physical data structures in a DBMS environment.
8927520
Vague Spatial Data Types, Set Operations, and Predicates
Many geographical applications deal with spatial objects that cannot be adequately described by determinate, crisp concepts because of their intrinsically indeterminate and vague nature. Current geographical information systems and spatial database systems are unable to cope with this kind of data. To support such data and applications, we introduce vague spatial data types for vague points, vague lines, and vague regions. These data types cover and extend previous approaches and are part of a data model called VASA (Vague Spatial Algebra). Their formal framework is based on already existing, general exact models of crisp spatial data types, which simplifies the definition of the vague spatial model. In addition, we obtain executable specifications for the operations which can be immediately used as implementations. This paper gives a formal definition of the three vague spatial data types as well as some basic operations and predicates. A few example queries illustrate the embedding and expressiveness of these new data types in query languages.
2130066
Fuzzy topological predicates, their properties, and their integration into query languages
For a long time topological relationships between spatial objects have been a main focus of research on spatial data handling and reasoning. They have especially been integrated into query languages of spatial database systems and geographical information systems. One of their fundamental features is that they operate on spatial objects with precisely defined, sharp boundaries. But in many geometric and geographic applications there is a need to model spatial phenomena and their topological relationships rather through vague or fuzzy concepts due to indeterminate boundaries. This paper presents a model of fuzzy regions and focuses on the definition of topological predicates between them. Moreover, some properties of these predicates are shown, and we demonstrate how the predicates can be integrated into a query language.
12411101
Topological Relationships Between Complex Lines and Complex Regions
Topological relationships between spatial objects in the two-dimensional space have been investigated for a long time in a number of disciplines like artificial intelligence, cognitive science, linguistics, and robotics. In the context of spatial databases and geographical information systems, as predicates they especially support the design of suitable query languages for spatial data retrieval and analysis. But so far, they have only been defined for simplified abstractions of spatial objects like continuous lines and simple regions. With the introduction of complex spatial data types in spatial data models and extensions of commercial database systems, an issue arises regarding the design, definition, and number of topological relationships operating on these complex types. This paper first introduces a formally defined, conceptual model of general and versatile spatial data types for complex lines and complex regions. Based on the well known 9-intersection model, it then formally determines the complete set of mutually exclusive topological relationships between complex lines and complex regions. Completeness and mutual exclusion are shown by a proof technique called proof-by-constraint-and-drawing.
14013704
Ambient Intelligence in Edutainment: Tangible Interaction with Life-Like Exhibit Guides
We present COHIBIT, an edutainment exhibit for theme parks in an ambient intelligence environment. It combines ultimate robustness and simplicity with creativity and fun. The visitors can use instrumented 3D puzzle pieces to assemble a car. The key idea of our edutainment framework is that all actions of a visitor are tracked and commented by two life-like guides. Visitors get the feeling that the anthropomorphic characters observe, follow and understand their actions and provide guidance and motivation for them. Our mixed-reality installation provides a tangible, (via the graspable car pieces), multimodal, (via the coordinated speech, gestures and body language of the virtual character team) and immersive (via the large-size projection of the life-like characters) experience for a single visitor or a group of visitors. The paper describes the context-aware behavior of the virtual guides, the domain modeling and context classification as well as the event recognition in the instrumented environment.
10276591
Multiscale methods for the segmentation and reconstruction of signals and images
This paper addresses the problem of both segmenting and reconstructing a noisy signal or image. The work is motivated by large problems arising in certain scientific applications, such as medical imaging. Two objectives for a segmentation and denoising algorithm are laid out: it should be computationally efficient and capable of generating statistics for the errors in the reconstruction and estimates of the boundary locations. The starting point for the development of a suitable algorithm is a variational approach to segmentation (Shah 1992). This paper then develops a precise statistical interpretation of a one dimensional (1-D) version of this variational approach to segmentation. The 1-D algorithm that arises as a result of this analysis is computationally efficient and capable of generating error statistics. A straightforward extension of this algorithm to two dimensions would incorporate recursive procedures for computing estimates of inhomogeneous Gaussian Markov random fields. Such procedures require an unacceptably large number of operations. To meet the objective of developing a computationally efficient algorithm, the use of previously developed multiscale statistical methods is investigated. This results in the development of an algorithm for segmenting and denoising which is not only computationally efficient but also capable of generating error statistics, as desired.
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.