Compiling ER Specifications into Declarative Programs

This paper proposes an environment to support high-level database programming in a declarative programming language. In order to ensure safe database updates, all access and update operations related to the database are generated from high-level descriptions in the entity- relationship (ER) model. We propose a representation of ER diagrams in the declarative language Curry so that they can be constructed by various tools and then translated into this representation. Furthermore, we have implemented a compiler from this representation into a Curry program that provides access and update operations based on a high-level API for database programming.Comment: Paper presented at the 17th Workshop on Logic-based Methods in Programming Environments (WLPE2007

A model-based approach to service creation

This paper presents a model-based approach to support service creation. In this approach, services are assumed to be created from (available) software components. The creation process may involve multiple design steps in which the requested service is repeatedly decomposed into more detailed functional parts, until these parts can be mapped onto software components. A modelling language is used to express and enable analysis of the resulting designs, in particular the behaviour aspects. Methods are needed to verify the correctness of each design step. A technique called behaviour refinement is introduced to assess the conformance relation between an abstract behaviour and a more concrete (detailed) behaviour. This technique is based on the application of abstraction rules to determine the abstraction of the concrete behaviour such that the obtained abstraction can be compared to the original abstract behaviour. The application of this refinement technique throughout the creation process enforces the correctness of the created servic

Using formal metamodels to check consistency of functional views in information systems specification

UML notations require adaptation for applications such as Information Systems (IS). Thus we have defined IS-UML. The purpose of this article is twofold. First, we propose an extension to this language to deal with functional aspects of IS. We use two views to specify IS transactions: the first one is defined as a combination of behavioural UML diagrams (collaboration and state diagrams), and the second one is based on the definition of specific classes of an extended class diagram. The final objective of the article is to consider consistency issues between the various diagrams of an IS-UML specification. In common with other UML languages, we use a metamodel to define IS-UML. We use class diagrams to summarize the metamodel structure and a formal language, B, for the full metamodel. This allows us to formally express consistency checks and mapping rules between specific metamodel concepts. (C) 2007 Elsevier B.V. All rights reserved

Simulation for business processes and information systems design

Business Process (BP) literature promotes the value of business processes as essential gearwheels that help organizations to reach their goals. Similarly, many process design approaches claim that Information Technology (IT) is a major enabler of business process, a view also shared by the Information Systems (IS) community. Despite this, BP and IS approaches do not provide clear guidance on how to assess the benefits that a given IS design may bring to the BP prior the IS implementation. Nor is clear indication of which modeling techniques could be used to assess such relationship. This paper uses the insights gained during a UK funded research project, namely ASSESS-IT, that aimed to depict the dynamic relationships between BP and IT to propose an alternative framework to develop BP simulation models that depict the dynamic behavior of the relationships between BP and IS

AGM, a dataflow database machine

In recent years, a number of database machines consisting of large numbers of parallel processing elements have been proposed. Unfortunately, one of the main limitations to parallelism in database processing is the I/O bandwidth of the underlying storage devices. One way to solve this problem is to use multiple parallel disk units. The main problem with this approach, however, is the lack of a computational model capable of utilizing the potential of any significant number of such devices.This paper presents a database model which is based on the principles of data-driven computation. According to this model, the database is represented as a network in which each node is conceptually an independent processing element, capable of communicating with other nodes by exchanging messages along the network arcs. To answer a query, one or more such messages, called tokens, are created and injected into the network. These then propagate asynchronously through the network in the search of results satisfying the given query.To investigate the performance of the proposed system, we have implemented the model on a simulated computer architecture. The results of the simulation ex-periments indicate that the model is capable of exploiting the potential I/O band-width of a large number of disk units as well as the computational power of the associated processing elements