Abstract. In this work we analyse the relation between hierarchical distancebased clustering and the concepts that can be obtained from the hierarchy by generalisation. Many inconsistencies may arise, because the distance and the conceptual generalisation operator are usually incompatible. To overcome this, we propose an algorithm which integrates distance-based and conceptual clustering. The new dendrograms can show when an element has been integrated to the cluster because it is near in the metric space or because it is covered by the concept. In this way, the new clustering can differ from the original one but the metric traceability is clear. We introduce three different levels of agreement between the clustering hierarchy obtained from the linkage distance and the new hierarchy, and we define properties these generalisation operators should satisfy in order to produce distance-consistent dendrograms.

Graphical notations have demonstrated usefulness when interacting with end users, making system validation easier. However, while they can be easily communicated, they lack precision, which consequently can be ambiguous and lead to misunderstanding. It is here where formal specifications can play an important role in overcoming this drawback. In this chapter, we use the RAISE Specification Language (RSL), which is the language of the formal method RAISE (i.e., Rigorous Approach to Industrial Software), as a syntactic and semantic reference for UML. We present the semantics for UML class diagrams by using RSL as a formal basis. An automated tool that implements the translation and the abstract syntax in RSL for the RSL-translatable class diagrams are also presented.

Abstract. In this work we analyse the relationship between distance and generalisation operators for real numbers, nominal data and tuples in the context of hierarchical distance-based conceptual clustering (HDCC). HDCC is a general approach to conceptual clustering that extends the traditional algorithm for hierarchical clustering by producing conceptual generalisations of the discovered clusters. This makes it possible to combine the flexibility of changing distances for several clustering problems and the advantage of having concepts which are crucial for tasks as summarisation and descriptive data mining in general. In this work we propose a set of generalisation operators and distances for the data types mentioned before and we analyse the properties by them satisfied on the basis of three different levels of agreement between the clustering hierarchy obtained from the linkage distance and the hierarchy obtained by using generalisation operators.

As a general rule, all engineering applications use mathematics or mathematical tools as a basis for their development. However, software engineering is an exception to this rule.

The development of wide software systems is an activity that consumes great quantities of time and resources. Even with the increase of the automation in the software development activities, the resources stay scarce. As a consequence of this, there is a big interest in the metrics of software due to its potential for a better, more e f ficient use of the resources. Tools help and assist in the planning and in the estimation of the complexity of the applications to develop during diff erent stage of a process.We describe a technique to define metrics using the OMG (Object Management Group) standard specification. The semantic in each metrics is specified formally with OCL (Object Constraint Language) based on OMG metamodels. For their concrete specification, we establish a series of steps that allows define uniformly each metric in the diff erent RUP models.Furthermore, the present paper shows the use of metrics defined using this technique and the relation between data obtained from the application of the metrics to thirteen object oriented systems. They encompass projects from the capture of requirements until its implementation, showing the metrics applied in dif f erent stage of the deployment.

No abstract

No abstract

Questions such as what are Formal Methods, how are Formal Methods implemented, how are they used in Software Engineering and when should they be used, among other related questions, are the main objective of this article. Some definitions are given to answer some of these questions; the article also states the aims of FM as well as it gives their main characteristics. An example that shows how Formal Methods can be used for specifying not only software requirements but also the rest of the stages in a software development process is given. A discussion about when they should be used, explaining the reasons why they should be applied when security and reliability are important requirements of the software under development, is presented. Finally, some arguments about how they can also be used as a complement to traditional development methods are provided.