This book is about model-based diagnosis of a class of discrete-event systems called active systems. Roughly, model-based diagnosis is the task of finding out the faulty components of a physical system based on the observed behavior and the system model. An active system is the abstraction of a physical artefact that is modeled as a network of com municating automata. For example, the protection apparatus of a power transmission network can be conveniently modeled as an active system, where breakers, protection devices, and lines are naturally described by finite state machines. The asynchronous occurrence of a short circuit on a line or a bus-bar causes the reaction of the protection devices, which aims to isolate the shorted line. This reaction can be faulty and several lines might be eventually isolated, rather than the shorted line only. The diagnostic problem to be solved is uncovering the faulty devices based the visible part of the reaction. Once the diagnosis task has been on accomplished, the produced results are exploited to fix the apparatus (and also to localize the short circuit, in this sample case). Interestingly, the research presented in this book was triggered a decade ago by a project 011 short circuit localization, conducted by ENEL, the Italian electricity board, along with other industrial and academic European partners."

This monograph describes an innovative prototyping framework for data and knowledge intensive systems. The proposed approach will prove especially useful for advanced and research-oriented projects that aim to develop a traditional database perspective into fully-fledged advanced database approaches and knowledge engineering technologies. The book is organised in two parts. The first part, comprising chapters 1 to 4, provides an introduction to the concept of prototyping, to database and knowledge-based technologies, and to the main issues involved in the integration of data and knowledge engineering. The second part, comprising chapters 5 to 12, illustrates the proposed approach in technical detail. Audience: This volume will be of interest to researchers in the field of databases and knowledge engineering in general, and for software designers and knowledge engineers who aim to expand their expertise in data and knowledge intensive systems.

Databaseprogrammingis the process ofdeveloping data-intensiveapplications which demand the access to large amounts of structured, persistent data. The primary tool required for implementing such applications is a database programming language, namely aformal language which is specialized in the definition and manipulationof relevant large-scale data. As such, a database programming language is expected to provide high-level data modeling capabilitiesas well as avarietyofconstructs which facilitatethehandlingofthespecifieddata. Inthis perspective, the aim of this book is: (i) to present the recent advances in database technologyfrom theviewpointofthe novel database paradigmsproposedfor the developmentofadvanced, non-standard, data-intensive applications, (ii) to focus specificallyon the relational approach, with considerableemphasis on the extensions proposed in the last decade, and (iii) to describe the extended relational database languageAlgres which is primarily the outcome of research work conducted by the authorsincooperationwithalargenumberofothercolleaguesandstudents. Furthermore, in orderto put the concepts presented in the book into practice, the reader is invited to experiment with the Algres system, afree copyofwhich can be requestedfromKluwerAcademicPublishers,ordirectlyfromtheauthors. Dependingonthespecific interest andbackgroundofthereader,thebookcanserve either:(1) to overview recent trends in databases, (2) to introduce in more detail the concepts and theory of the nested relational model, or (3) to present a complete advancedrelationallanguagewhichcanbefreelyusedforexperimentalpurposeswithin academicandresearchframeworks.

This monograph describes an innovative prototyping framework for data and knowledge intensive systems. The proposed approach will prove especially useful for advanced and research-oriented projects that aim to develop a traditional database perspective into fully-fledged advanced database approaches and knowledge engineering technologies. The book is organised in two parts. The first part, comprising chapters 1 to 4, provides an introduction to the concept of prototyping, to database and knowledge-based technologies, and to the main issues involved in the integration of data and knowledge engineering. The second part, comprising chapters 5 to 12, illustrates the proposed approach in technical detail. Audience: This volume will be of interest to researchers in the field of databases and knowledge engineering in general, and for software designers and knowledge engineers who aim to expand their expertise in data and knowledge intensive systems.

This book is about model-based diagnosis of a class of discrete-event systems called active systems. Roughly, model-based diagnosis is the task of finding out the faulty components of a physical system based on the observed behavior and the system model. An active system is the abstraction of a physical artefact that is modeled as a network of com municating automata. For example, the protection apparatus of a power transmission network can be conveniently modeled as an active system, where breakers, protection devices, and lines are naturally described by finite state machines. The asynchronous occurrence of a short circuit on a line or a bus-bar causes the reaction of the protection devices, which aims to isolate the shorted line. This reaction can be faulty and several lines might be eventually isolated, rather than the shorted line only. The diagnostic problem to be solved is uncovering the faulty devices based the visible part of the reaction. Once the diagnosis task has been on accomplished, the produced results are exploited to fix the apparatus (and also to localize the short circuit, in this sample case). Interestingly, the research presented in this book was triggered a decade ago by a project 011 short circuit localization, conducted by ENEL, the Italian electricity board, along with other industrial and academic European partners."