this article, we discuss the special characteristics of online yellow pages and product catalogs, examine linguistic ontologies' role in content matching, and present OntoSeek's architecture. Understanding yellow pages and product catalogs Online yellow pages locate suppliers based on a generic natural-language (NL) description of their products and services; product catalogs let users select a specific product or service offered by a certain supplier. These repositories' peculiarities, with respect to generic Web documents, can be roughly characterized by four parameters (see Table 1 for their estimated values): . vocabulary size: number of concepts necessary to formalize all descriptions in the repository; . description complexity: average number of concepts for one description; . description heterogeneity: average number of semantic relations in a description with respect to the t

Several authors have identified that the only feasible way to increase productivity in software construction is to reuse existing software. To achieve this, component-based software development is one of the more promising approaches. However, traditional research in component-oriented programming often assumes that components are reused "as-is". Practitioners have found that "as-is" reuse seldomly occurs and that reusable components generally need to be adapted to match the system requirements. Existing component object models provide only limited support for component adaptation, i.e. white-box techniques such as copy-paste and inheritance and black-box approaches such as aggregation and wrapping. These techniques suffer from problems related to reusability, efficiency, implementation overhead or the self problem. To address these problems, this paper proposes superimposition, a novel black-box adaptation technique that allows one to impose predefined, but configurable types ...

A safety case should present a clear, comprehensive and defensible argument that a system is acceptably safe to operate within a particular context. However, many existing safety cases, in their attempt to manage potentially complex arguments, are poorly structured, presented and understood. This creates problems in developing and maintaining safety cases, and in capturing successful safety arguments for use on future projects. This thesis defines and demonstrates a coherent approach to the development, presentation, maintenance and reuse of the safety arguments within a safety case. This approach is based upon a graphical technique -- the Goal Structuring Notation (GSN) -- and has three strands. Firstly, a method for the use of GSN is defined together with an approach to supporting incremental safety case development. Secondly, the thesis presents a systematic process for the maintenance of a GSN-structured safety argument. Thirdly, the concept of `Safety Case Patterns' is defined as a means of supporting and promoting the reuse of successful safety arguments between safety cases. Examples of the approach are provided throughout. Evaluation of the approach is described through tool implementation, case studies, pilot projects and industrial project applications. Through these activities the approach has been shown to be both a valid and capable tool for safety case management.

The ability to rapidly locate useful on-line services (e.g. software applications, software components, process models, or service organizations), as opposed to simply useful documents, is becoming increasingly critical in many domains. Current service retrieval technology is, however, notoriously prone to low precision. This paper describes a novel service retrieval approached based on the sophisticated use of process ontologies. Our preliminary evaluations suggest that this approach offers qualitatively higher retrieval precision than existing (keyword and tablebased) approaches without sacrificing recall and computational tractability/scalability.

The ability to rapidly locate useful on-line services (e.g. software applications, software components, process models, or service organizations), as opposed to simply useful documents, is becoming increasingly critical in many domains. As the sheer number of such services increases it will become increasingly more important to provide tools that allow people (and software) to quickly find the services they need, while minimizing the burden for those who wish to list their services with these search engines. This can be viewed as a critical enabler of the `friction-free' markets of the `new economy'. Current service retrieval technology is, however, seriously deficient in this regard. The information retrieval community has focused on the retrieval of documents, not services per se, and has as a result emphasized keyword-based approaches. Those approaches achieve fairly high recall but low precision. The software agents and distributed computing communities have developed...

We consider the problem of software generalization: Given a program component C, create a parameterized program component C' such that C' is usable in a wider variety of syntactic contexts than C. Furthermore, C' should be a semantically meaningful generalization of C; namely, there must exist an instantiation of C' that is equivalent in functionality to C. In this paper, we present an algorithm that generalizes C functions via type inference. The original functions operate on specific data types; the result of generalization is a collection of C++ function templates that operate on parameterized types. This version of the generalization problem is useful in the context of converting existing C programs to C++.

Abstract not found

. In this paper we present a mechanism for making specification-based component retrieval more efficient by limiting the amount of theorem proving required at query time. This is done by using a classification scheme to reduce the number of specification matching proofs that are required to process a query. Components are classified by assigning features that correspond to necessary conditions implied by the component specifications. We show how this method of feature assignment can be used to approximate reusability relationships between queries and library components. The set of possible classification features are formally defined, permitting automation of the classification process. The classification process itself is made efficient by using a specialized theorem proving tactic to prove feature implication. The retrieval mechanism was implemented and evaluated experimentally using a library of list manipulation components. The results indicate a better response time than existing ...

Although software reuse can improve both the quality and productivity of software development, it will not do so until software developers stop believing that it is not worth their effort to find a component matching their current problem. In addition, if the developers do not anticipate the existence of a given component, they will not even make an effort to find it in the first place. Even the most sophisticated and powerful reuse repositories will not be effective if developers don't anticipate a certain component exists, or don't deem it worthwhile to seek for it. We argue that this crucial barrier to reuse is overcome by integrating active information delivery, which presents information without explicit queries from the user, and reuse repository systems. A prototype system, CodeBroker, illustrates this integration and raises several issues related to software reuse.

this paper adopts a language of limited expressiveness, privileging the simplicity of use as the most important requirement. We adopt a very simple graph structure for representing both queries and component data, but -- differently from most of current systems -- we do not assume the user to have familiarity with the vocabulary used for component encoding, relying on a large linguistic ontology like Sensus [Swartout et al. 1996] to perform the match between queries and data. In the encoding phase (which we assume to be a manual process supported by an interactive environment), a software analyst describes a component by a simple graph where nodes and arcs are labelled with English words. Since binary relations are not usually denoted by nouns, a special semantics is adopted for this graph, which is called Lexical Semantic Graph. English nouns appearing in the graph are recognized by a lexical interface based on Wordnet [Miller 1995], which asks the analyst to choose among possibly different senses associated to each word. The graph of words is therefore translated into a graph of senses, each one corresponding to a node in the Sensus ontology. The query graph is built by the user in a similar way, but the words chosen and the corresponding senses can be of course different, as well as the structure of the graph. Conceptually, the search process implements a graph matching algorithm, returning the identifiers of all components whose description is subsumed by the query. In the following section, we describe the main design choices of a project on software retrieval currently going on at Corinto 1 , a research consortium established to study and promote object-oriented technology. In section 3 we present the encoding and retrieval process in some detail, with the help of...