Search

In the description of complex objects, we need methods which could reflect the complex interconnections between components and sift out if possible those of them which are substantial for the specific application. It is offered in this publication the pattern recognition methods should be used as a unified method for processing of data from complex objects. The proposed algorithm may be used in the recognition of the condition of objects of various nature. The indicated examples prove the practical applicability of the methodology as they represent the solution of specific practical problems.

Making sense of complex objects is difficult, and typically requires the use of external representations to support cognitive demands while reasoning about the objects. Visualizations are one type of external representation that can be used to support sensemaking activities. In this paper, we investigate the role of two design strategies in making the interactive features of visualizations more supportive of users’ exploratory needs when trying to make sense of complex objects. These two strategies are visibility and complementarity of interactions. We employ a theoretical framework concerned with human–information interaction and complex cognitive activities to inform, contextualize, and interpret the effects of the design strategies. The two strategies are incorporated in the design of Polyvise, a visualization tool that supports making sense of complex four-dimensional geometric objects. A mixed-methods study was conducted to evaluate the design strategies and the overall usability of Polyvise. We report the findings of the study, discuss some implications for the design of visualization tools that support sensemaking of complex objects, and propose five design guidelines. We anticipate that our results are transferrable to other contexts, and that these two design strategies can be used broadly in visualization tools intended to support activities with complex objects and information spaces.

Virtual Reality (VR) allows creating interactive three-dimen sional computer worlds in which objects have a sense of spatial and physical presence and can be manipulated by the user as such. Different software tools have been developed to build virtual worlds. However, most tools require considerable background knowledge about VR and the virtual world needs to be expressed in low-level VR primitives. This is one of the reasons why developing a virtual world is complex, time-consuming and expensive. Introducing a conceptual design phase in the development process will reduce the complexity and provides an abstraction layer to hide the VR implementation details. However, virtual worlds contain features not present in classical software. Therefore, new modeling concepts, currently not available in classical conceptual modeling languages, such as ORM or UML, are required. Next to introducing these new modeling concepts, it is also necessary to define their semantics to ensure unambiguousness and to allow code generation. In this paper, we introduce conceptual modeling concepts to specify complex connected 3D objects. Their semantics are defined using F-logic, a full-fledged logic following the object-oriented paradigm. F-logic will allow applying reasoners to check the consistency of the specifications and to investigate properties before the application is actually built.

The well-definedness problem for a programming language consists of checking, given an expression and an input type, whether the semantics of the expression is defined for all inputs adhering to the input type. A related problem is the semantic type-checking problem which consists of checking, given an expression, an input type, and an output type whether the expression always returns outputs adhering to the output type on inputs adhering to the input type. Both problems are undecidable for general-purpose programming languages. In this paper we study these problems for the Nested Relational Calculus, a specific-purpose database query language. We also investigate how these problems behave in the presence of prograrruning language features such as singleton coercion and type tests. (c) 2006 Elsevier B.V. All rights reserved.