Luis Iribarne

A Trading Service for COTS Components

Component-based software development (CBSD) has gained recognition as one of the key technologies for the construction of high-quality, evolvable, large complex systems in a timely and affordable manner. In CBSD, the development effort becomes one of gradual discovery about the components, their capabilities and the incompatibilities that arise when they are used in concert. Thus, trading becomes one of the cornerstones of CBSD. However, most of the existing methods for CBSD do not make effective use of traders. In this paper, we analyze the required features for commercial off-the-shelf (COTS) components traders, and introduce COTStrader ,a n Internet-based trader for COTS components. In addition, we discuss how the COTStrader can be integrated into a spiral methodology for CBSD, providing partially automated support for building COTS-based systems.

A new virtual task to evaluate human place learning

This study assesses the effectiveness of a new virtual task to evaluate human place learning. This test was based on the hole-board maze, developed for rodent research. Its design provides an easy set of levels of difficulty. Sixty-three undergraduate students (30 men and 33 women) were randomly distributed into three testing conditions; they had to find 3, 5 and 7 rewards, respectively, in a virtual room with 16 possible rewarded positions. Subjects were asked to use the minimum amount of attempts to discover all the rewards in 10 trials. In the initial trial subjects needed to visit almost all the positions to discover the rewards. However, in the last trial an important percentage of subjects did not err. Results showed that all subjects acquired the task but with different amounts of mistakes directly related to the level of difficulty of the condition. In addition, women were slower and less accurate than men. These results agree with previous results in other virtual tasks, and support the spatial component of this test.

Designing GUI components from UML use cases

In this paper we present how to develop graphical user interfaces from two UML models: use case and activity diagrams. Our method obtains from them a UML class diagram for representing GUI components, and it is suitable for generating code fragments, which can be considered as GUI prototypes.

An extension of UML for the modeling of WIMP user interfaces

The Unified Modeling Language (UML) [OMG, Unified Modeling Language Specification, Version 2.0, Technical Report, Object Management Group , 2005] provides system architects working on analysis and design (A&D) with one consistent language for specifying, visualizing, constructing, and documenting the artifacts of software systems, as well as for the business modeling. The user interface (UI), as a significant part of most applications, should be modeled using UML, and automatic CASE tools may help to generate UIs from UML designs. In this paper, we describe how to use and specialize UML diagrams in order to describe the UIs of a software system based on WIMP (Windows, Icons, Menus and Pointers). Use case diagrams are used for extracting the main UIs. Use cases are described by means of user-interaction diagrams, a special kind of activity diagrams in which states represent data output actions and transitions represent data input events. Input and output interactions in the user-interaction diagrams help the designer to extract the UI components used in each UI. We obtain a new and specialized version of the use case diagram for the UI modeling (called UI diagram) and a class diagram for UI components-called UI-class diagram. The user-interaction, UI and UI-class diagrams, can be seen as the UML-based UI models of the system. Finally, UI prototypes can be generated from UI-class diagrams with CASE tool support. As case study of our technique, we will describe an Internet book shopping system.

Describing use cases with activity charts

The Model-Driven Development (MDD) describes and maintains models of the system under development. The Unified Modeling Language (UML) supports a set of semantics and notation that addresses all scales of architectural complexity by using a MDD perspective. Use Cases and Activity Charts are two modeling techniques of the UML. The first one helps the designers to identify the requirements of the system discovering its high level functionality. The second one helps them to specify the internal behaviour of a certain entity or subsystem of the software developed, such as a database, a graphical interface, a software component, or any specific software. However, there is not a direct way to relate/model the requirements (use cases) with their internal behavior (activity charts). In this paper we present a method for describing use cases with activity charts. Our technique also allow us to identify the two main use case relationships —include and generalization— by means of activity charts. As a case study, we will show how to use the activity charts to describe graphical user interfaces (GUI) from use cases. In particular, we will show an Internet book shopping system example.

Describing Use-Case Relationships with Sequence Diagrams

One of the key tools of the unified modelling language for behaviour modelling is the use-case model. The behaviour of a use case can be described by means of interaction diagrams (sequence and collaboration diagrams), activity charts and state diagrams or by pre-conditions and post-conditions, as well as natural language text, where appropriate. This article explains a technique to describe use cases by means of sequence diagrams. It compares sequence diagrams in order to define sequence-diagram relationships for identifying and defining use-case relationships. This article uses an automatic teller machine system case study to illustrate our proposal.

A Model Transformation Approach for Automatic Composition of COTS User Interfaces in Web-Based Information Systems

Globalization of the information and the Knowledge Society requires the modernization of Web-based Information Systems (WIS) into evolutive and adaptable user interfaces. Today, WIS user interfaces are built following traditional development paradigms. This article is inspired on a Model-Driven Development (MDD) perspective to produce runtime automatic composition of user interfaces from model and metamodel representations of widgets-type COTS interface components architectures and model transformation.

Contextual and Hierarchical Classification of Satellite Images Based on Cellular Automata

Satellite image classification is an important technique used in remote sensing for the computerized analysis and pattern recognition of satellite data, which facilitates the automated interpretation of a large amount of information. Today, there exist many types of classification algorithms, such as parallelepiped and minimum distance classifiers, but it is still necessary to improve their performance in terms of accuracy rate. On the other hand, over the last few decades, cellular automata have been used in remote sensing to implement processes related to simulations. Although there is little previous research of cellular automata related to satellite image classification, they offer many advantages that can improve the results of classical classification algorithms. This paper discusses the development of a new classification algorithm based on cellular automata which not only improves the classification accuracy rate in satellite images by using contextual techniques but also offers a hierarchical classification of pixels divided into levels of membership degree to each class and includes a spatial edge detection method of classes in the satellite image.

Toward the adaptation of component-based architectures by model transformation: behind smart user interfaces

Graphical user interfaces are not always developed for remaining static. There are GUIs with the need of implementing some variability mechanisms. Component‐based GUIs are an ideal target for incorporating this kind of operations, because they can adapt their functionality at run‐time when their structure is updated by adding or removing components or by modifying the relationships between them. Mashup user interfaces are a good example of this type of GUI, and they allow to combine services through the assembly of graphical components. We intend to adapt component‐based user interfaces for obtaining smart user interfaces. With this goal, our proposal attempts to adapt abstract component‐based architectures by using model transformation. Our aim is to generate at run‐time a dynamic model transformation, because the rules describing their behavior are not pre‐set but are selected from a repository depending on the context. The proposal describes an adaptation schema based on model transformation providing a solution to this dynamic transformation. Context information is processed to select at run‐time a rule subset from a repository. Selected rules are used to generate, through a higher‐order transformation, the dynamic model transformation. This approach has been tested through a case study which applies different repositories to the same architecture and context. Moreover, a web tool has been developed for validation and demonstration of its applicability. The novelty of our proposal arises from the adaptation schema that creates a non pre‐set transformation, which enables the dynamic adaptation of component‐based architectures. Copyright

Trading for COTS components in open environments

Trading is a well-known mechanism for searching and locating services in object-oriented systems. However, current traders present some limitations when used in open component-based system environments. In this paper we analyze the required features that COTS components traders should have, and describe the design and implementation of COTStrader; an Internet-based trader for COTS components that handles the heterogeneity, scalability and evolution of COTS traders.