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Technical Report Series


The Department of Computer Science of the University of Malta maintains this Technical Report Series, in which current research carried out by staff members and students can be published.

If you require any further information, please contact reports@cs.um.edu.mt.

The LaTeX class file for the technical report series, and an example dummy report can be downloaded from here.

 

ReportCS-2012-01
TitleSeparating Compensation Concerns and Programming them with Compensating Automata
AuthorsChristian Colombo and Gordon J. Pace
Abstract

Compensations have been used for decades in areas such as flow management systems, long-lived transactions and more recently in the service-oriented architecture. Since compensations enable the logical reversal of past actions, by their nature they cross-cut other programming concerns. Thus, intertwining compensations with the rest of the system not only makes programs less well-structured, but also limits the expressivity of compensations due to the tight coupling with the system's behaviour. 

To separate compensation concerns from the normal forward behaviour of the system, we propose a novel design paradigm in which compensations are programmed separately from the system, and incorporated within a compensation manager following relevant system events and manages compensations. If the system signals the need to be compensated, the manager triggers the execution of compensations on behalf of the system and subsequently returns control to the system. We show that this approach can be used to program a sophisticated real-life case study which existing compensation approaches have difficulty in handling. 

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Report

CS-2011-02
TitleAn Event-Driven Language for Cartographic Modelling of Knowledge in Software Development Organisations
AuthorsErnest Cachia, Mark Micallef and Christian Colombo
AbstractWith software engineering now being considered a fully-fledged knowledge industry in which the most valuable asset to an organisation is the knowledge held by its employees, high staff turnover rates are becoming increasingly worrying.  If software engineering organisations are to maintain their competitive edge, they need to ensure that their intellectual capital continues to grow and is not lost as people move in and out of their employ.
In this paper, the authors present work involving the formalisation of a language that enables organisations to create and analyse maps of their organisational knowledge.  In a more elaborate version of the traditional yellow-pages approach utilised in the cartographic school of thought, the proposed language models various relationships between knowledge assets, uses an event-driven mechanism to determine who knows what within the organisation, and finally provides metrics for detecting three types of risk related to knowledge management in modern software engineering.  A three month evaluation of the language is also outlined and results discussed.
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ReportCS-2011-01
TitleA Compensating Transaction Example in Twelve Notations
AuthorsChristian Colombo and Gordon J. Pace
AbstractThe scenario of business computer systems changed with the advent of cross-entity computer interactions: computer systems no longer had the limited role of storing and processing data, but became themselves the players which actuated real-life actions. These advancements rendered the traditional transaction mechanism insufficient to deal with these new complexities of longer multi-party transactions. The concept of compensations has long been suggested as a solution, providing the possibility of executing "counter"-actions which semantically undo previously completed actions in case a transaction fails. There are numerous design options related to compensations particularly when deciding the strategy of ordering compensating actions. Along the years, various models which include compensations have emerged, each tackling in its own way these options. In this work, we review a number of notations which handle compensations by going through their syntax and semantics --- highlighting the distinguishing features --- and encoding a typical compensating transaction example in terms of each of these notations.
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ReportCS-2009-02
TitleEmbedded Languages for Business Process Modelling, Transformation and Quality Assurance in Business-Driven Development
AuthorsLuana Micallef and Gordon J. Pace
Abstract
In Business-Driven Development (BDD), process models are produced by business analysts. To ensure that the defined requirements are satisfied, the IT solution must ideally be derived directly from the specifications through a process of model refinement. However, if the original models contain errors or lack some technical detail, an incorrect implementation would be inferred and the entire BDD life-cycle would have to be revised. In this report, we investigate the use of embedded language techniques to enable more abstract model descriptions and enable quality assurance and transformation of models. We have embedded such a domain-specific language in the functional programming language Haskell and show how it enables: (i) the rapid development of models in a concise and abstract manner, focusing on the specifications rather than the implementation and ensuring that all the required details to generate the executable code are specified; (ii) quality assurance of the models through the use of Haskell's type checker, at construction-time and through soundness analysis; (iii) transformation, analysis and interpretation of the models; and (iv) definition of composite model transformations, including the use of quality assurance.
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ReportCS-2009-01
TitleResource-Bounded Runtime Verification of Java Programs with Real-Time Properties
AuthorsChristian Colombo, Gordon J. Pace and Gerardo Schneider
AbstractGiven the intractability of exhaustively verifying software, the use of runtime verification, to verify single execution paths at runtime, is becoming increasingly popular. Undoubtedly, the overhead introduced by runtime verification is a concern for system developers planning to introduce this technique in their work. By using Lustre to write security-critical properties, we exploit the language's guarantees on bounded resources. We translate these properties into the existing monitoring framework Larva, making monitoring of programs both easily applicable to Java programs and at the same time guarantee to use bounded-resources. We use a subset of Quantified Discrete-time Duration Calculus (QDDC) as an alternative specification notation for real-time properties because it is translatable into Lustre. Thus, QDDC also enjoys the same guarantees given when using Lustre.
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ReportCSAI-2008-01
TitleMulti-Stage Languages in Hardware Design
AuthorsGordon J. Pace and Christian Tabone
AbstractAs circuits increase in size and complexity, hardware description techniques have been trying to adopt features already wellestablished in software languages. In this paper, we investigate how different hardware description languages implement levels of abstraction over the hardware designs, and we examine how improvements have lead to features like parameterised circuits and generic descriptions, that enable users to efficiently model and reason about large regular-shaped structures and connection patterns. Nonetheless, the ability to include non-functional properties of circuits in the same description is still an open issue. Lately, proposed solutions are looking into meta-functional languages and multi-staging techniques. We examine how hardware description languages can benefit from the capabilities of meta-functional languages, which are able to reason about, and transform the circuit generators as data objects, thus providing a means to access both the functional and non-functional aspects of the generated circuits.
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ReportCSAI-2007-01
TitleProceedings of CSAW'07
AuthorsClaudia Borg, Sandro Spina and Charlie Abela
AbstractThis report contains the proceedings of the fifth Computer Science Annual Workshop (CSAW’07) - the research workshop held by the Departments of Computer Science and Artificial Intelligence of the University of Malta.
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ReportCSAI-2006-01
TitleProceedings of CSAW'06
AuthorsJohn Abela, Angelo Dalli and Kristian Guillaumier
AbstractThis report contains the proceedings of the fourth Computer Science Annual Workshop (CSAW’06) - the research workshop held by the Departments of Computer Science and Artificial Intelligence of the University of Malta.
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ReportCSAI-2005-02
TitleProceedings of CSAW'05
AuthorsErnest Cachia and Mark Micallef
AbstractThis report contains the proceedings of the third Computer Science Annual Workshop (CSAW’05) - the research workshop held by the Departments of Computer Science and Artificial Intelligence of the University of Malta.
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ReportCSAI-2005-01
TitleAutomatic Document Clustering using Topic Analysis
AuthorsRobert Muscat
AbstractIn this work we look at the automated organisation of documents in a document base into clusters and cluster hierarchies. We apply topic segmentation to detect topics within documents and using term relationships attempt to build hierarchies which represent a "real world" topic hierarchy. Finally, we assign documents to each of these topics using a standard clustering technique. We also propose two evaluation methods for document clustering systems. The first is an adaptation of tree measure algorithms to document hierarchies. The use of this method will require a pre-defined tree which has been agreed upon as a suitable benchmark. The second is independent of any benchmark trees and presents the evaluator with a number of measures which al low him to assess the properties of the tree.
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ReportCSAI-2004-02
TitleProceedings of CSAW'04
AuthorsGordon J. Pace and Joseph Cordina
AbstractThis report contains the proceedings of the second Computer Science Annual Workshop (CSAW’04) - the research workshop held by the Departments of Computer Science and Artificial Intelligence of the University of Malta.
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Report
CSAI-2004-01
Title
Support Vector Machines with Profile-Based Kernels for Remote Protein Homology Detection
Authors
Steven Busuttil, John Abela and Gordon J. Pace
Abstract
Two new techniques for remote protein homology detection particulary suited for sparse data are introduced. These methods are based on position specific scoring matrices or profiles and use a support vector machine (SVM) for discrimination. The performance on standard benchmarks outperforms previous non-discriminative techniques and is comparable to that of other SVM-based methods while giving distinct advantages.
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Report
CSAI-2003-02
Title
Proceedings of CSAW'03
Authors
Gordon J. Pace and Joseph Cordina
Abstract
This report contains the proceedings of the first Computer Science Annual Workshop (CSAW’03) - the research workshop held by the Departments of Computer Science and Artificial Intelligence of the University of Malta.
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Report
CSAI-2003-01
Title
A New Breadth-First Search Algorithm for Deciding SPDI Reachability
Authors
Gordon J. Pace
Abstract
Polygonal hybrid systems are a subclass of planar hybrid automata which can be represented by piecewise constant differential inclusions (SPDIs). Using an important object of SPDIs’ phase portrait, the invariance kernels, which can be computed non-iteratively, we present a breadth-first search algorithm for solving the reachability problem for SPDIs. Invariance kernels play an important role in the termination of the algorithm.
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Notices
ICT Timetables 2011 / 12

ICT Timetables (Semester & Examinations) for Academic Year 2011/12, available from HERE.

1st Year ICT Matters 2011/12

Academic Advisors List 2011 / 2012

UoM Imagine Cup Team

Winners for the 9th consecutive year. More details in Here.

TNC2012: Terena Networking Conference 2012

Between the 21st of May 2012 and the 24th of May 2012 in Reykjavik (Iceland). More details in HERE.

MIME 2012 - How to Write a Scientific Paper

3 Day Intensive Course organized by The Malta Institute for Medical Education. More details in HERE.

 
 
Last Updated: 26 April 2012

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