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We present an approach to enable end-users to graphically compose their own applications directly on their mobile phone, mainly integrating the functionalities available on the device and those provided by pervasive and Internet services. To this aim, we propose a methodology and a graphical notation enabling the user to compose mobile applications, named MicroApps: the user creates an application following an incremental and iterative development process; he composes icons representing (pervasive) services mainly by touch-based selection and following a data-flow approach. He is not in charge of the creation of the user interface, which is automatically generated. The methodology enables the end-user to develop applications and/or compose services on the smartphone, so paving the way towards new scenarios where smartphones replace and overtake the Personal Computer, given their native possibility of wide connectivity, when augmented by features for interaction with remote systems and sensors. The methodology has been evaluated through an empirical analysis that revealed that in spite of the reduced size of the screen the use of the MicroApp Generator tool improves the effectiveness in terms of time and editing errors with respect to the use of MIT App Inventor [1] . [ABSTRACT FROM PUBLISHER]

The visualization of information contained in reports is an important aspect of human-computer interaction, for both the accuracy and the complexity of relationships between data must be preserved. A greater attention has been paid to individual report visualization through different types of standard graphs (Histograms, Pies, etc.). However, this kind of representation provides separate information items and gives no support to visualize their relationships which are extremely important for most decision processes. This paper presents a design methodology exploiting the visual language CoDe based on a logic paradigm. CoDe allows to organize the visualization through the CoDe model which graphically represents relationships between information items and can be considered a conceptual map of the view. The proposed design methodology is composed of four phases: the CoDe Modeling and OLAP Operation pattern definition phases define the CoDe model and underlying metadata information, the OLAP Operation phase physically extracts data from a data warehouse and the Report Visualization phase generates the final visualization. Moreover, a case study on real data is provided. [ABSTRACT FROM PUBLISHER]

As already documented in the literature, fractal image encoding is a family of techniques that achieves a good compromise between compression and perceived quality by exploiting the self-similarities present in an image. Furthermore, because of its compactness and stability, the fractal approach can be used to produce a unique signature, thus obtaining a practical image indexing system. Since fractal-based indexing systems are able to deal with the images in compressed form, they are suitable for use with large databases. In this paper, we propose a system called FIRE, which is then proven to be invariant under three classes of pixel intensity transformations and under geometrical isometries such as rotations by multiples of π/2 and reflections. This property makes the system robust with respect to a large class of image transformations that can happen in practical applications: the images can be retrieved even in the presence of illumination and/or color alterations. Additionally, the experimental results show the effectiveness of FIRE in terms of both compression and retrieval accuracy. [ABSTRACT FROM AUTHOR]

Examines virtual images for similarity retrieval in image databases. Representation of the spatial information contained in a real image; Computation of the similarity between a query and an image in the database; Invariance of image representation.

The diagrammatic approach to user interface for Computer-aided Software Development toolkits, Visual Query Systems, and Visual Programming Environments, is based on the use of diagrams and charts traditionally drawn on paper. In particular, the VLG system (Visual Language Generator) has been proposed to generate icon-oriented visual languages customized for given applications. The syntactical model underlying the interpretation of a visual language in VLG has been designed to describe icon-oriented visual languages. In order to enable the VLG system to apply to any kind of graphical languages, like diagrammatic ones, it is necessary to find a more general syntactical model able to support both their generation and interpretation. This paper addresses the comprehension of the features that a grammatical formalism for nonlinear languages must have to match any requirement for an efficient parsing. To this aim, relation grammars support an easy implementation of a general parsing algorithm for multidimensional languages, parametric with respect to the rewriting rules of the grammar. We compare the expressive power of relation grammars to grammatical formalisms for graph grammars, since graphs have often been used to represent nonlinear structures and recently graphs have played a central role in the development of diagrammatic systems for user interaction. We show that relation grammars are at least as powerful as two well known graph grammar formalisms. Our analysis demonstrates also some pleasant features of relation grammars compared to graph grammar models. The naturalness and the versatility of the generating process of relation grammars is especially useful when dealing with the automatic generation and interpretation of visual languages. The effectiveness of visual languages requires that efficient parsing techniques must be investigated, i.e., a good compromise has to be found between the expressiveness of the chosen formalism and the cost of parsing. As a solution, a significant subclass of Relation Grammars, called RG/1 has been isolated, for which an efficient parsing algorithm can be implemented. [ABSTRACT FROM AUTHOR]

Describes the Pittsburgh-Salerno Iconic System (PSIS) which let computer users design, specify and interpret visual languages for various applications. Popularity of computing environments for non-programmers; Description of the two major subsystems of PSIS; Features of the PSIS compiler.

The most important feature of visual languages is their ability to represent a user's mental concepts pictorially, thus providing for ease of learning and use. In order for this feature to be best exploited, there must be a close connection between the user's mental model of the application environment and the meaning of the icons in the system. Thus, a visual language must be accurately tuned to the application environment to which it is directed. This paper presents a system to generate and interpret customized visual languages in given application areas. The generation is highly automated. The user presents a set of sample visual sentences to the generator. The generator uses inference grammar techniques to produce a grammar that generalizes the initial set of sample sentences, and exploits general semantic information about the application area to determine the meaning of the visual sentences in the inferred language. The interpreter is modeled on an attribute grammar. A knowledge base, constructed during the generation of the system, is then consulted to construct the meaning of the visual sentence. The architecture of the whole system and its use in the application environment of visual text editing (inspired by the Heidelberg Icon Set) enhanced with file management features is reported. [ABSTRACT FROM AUTHOR]