Abstract
QVT Relations (QVT-R) is the standard language proposed by the OMG to specify bidirectional model transformations. Unfortunately, in part due to ambiguities and omissions in the original semantics, acceptance and development of effective tool support has been slow. Recently, the checking semantics of QVT-R has been clarified and formalized. In this paper we propose a QVT-R tool that complies to such semantics. Unlike any other existing tool, it also supports meta-models enriched with OCL constraints (thus avoiding returning ill-formed models), and proposes an alternative enforcement semantics that works according to the simple and predictable "principle of least change". The implementation is based on an embedding of both QVT-R transformations and UML class diagrams (annotated with OCL) in Alloy, a lightweight formal specification language with support for automatic model finding via SAT solving.

Abstract

Abstract
Althought optimistic concurrency control protocols have increasingly been used in distributed database management systems, they imply a trade-off between the number of transactions that can be executed concurrently, hence, the peak throughput, and transactions aborted due to conflicts. We propose a novel optimistic concurrency control mechanism that controls transaction abort rate by minimizing the time during which transactions are vulnerable to abort, without compromising throughput. Briefly, we throttle transaction execution with an adaptive mechanism based on the state of the transaction queues while allowing out-of-order execution based on expected transaction latency. Preliminary evaluation shows that this provides a substantial improvement in committed transaction throughput. Copyright 2013 ACM.

Abstract
The presence of code replication can be a consequence of a lack in the composition mechanisms where classes are insufficient to reuse the code that is replicated. To extend the reuse of pieces of code some proposals have been made that try to compose classes using those pieces of code. In this paper we compare two of those approaches: Traits and Roles. We compare their compositions mechanisms and how we can use them to reduce code replication. To study the extent to which they reduce code replication we conducted a case study using the JHotDraw framework where we detect and remove code replication using each technique. Results from the case study show that roles have an advantage over traits, as they are capable of removing more code replication.

Abstract
The central idea of the Web of Data is to interlink the information available in the Web, most of which is actually stored in databases rather than in static HTML pages. Tools to convert relational data into semantic web formats and publish then as linked data are essential to fulfill the vision of a web of data available for automatic processing, as web content is currently available to humans. This paper presents DaPress, a simple tool to publish linked data on the Web, that maps a relational database to an RDF triplestore and creates a SPARQL access point. The paper reports the use of DaPress to publish the database of Authenticus, a system that automatically assigns publication authors to known Portuguese researchers and institutions. © Teresa Costa and José Paulo Leal.

Abstract
This article describes an application proposal since the analysis till the development of a software, which presents itself as a solution to the existent management problem in the Electronics Store in the Engineering Department of University of Tras-os-Montes and Alto Douro. The study as followed a development methodology intrinsic to the problem and to all the features associated to management systems, with the main purpose to obtain a suitable solution by means of Information Technologies capable to support the users in the management of all services and resources of the store in a way completely integrated with the information systems that are more relevant to teaching activity. The solution was developed using Web technologies, enabling an optimized channel for accessing and managing all services and products provided by the store, increasing their efficiency, organization and ability to respond to requests made by all users.