Dimitris Antoniou

CODE QUALITY EVALUATION METHODOLOGY USING THE ISO/IEC 9126 STANDARD

This work proposes a methodology for source code quality and static behaviour evaluation of a software system, based on the standard ISO/IEC-9126. It uses elements automatically derived from source code enhanced with expert knowledge in the form of quality characteristic rankings, allowing software engineers to assign weights to source code attributes. It is flexible in terms of the set of metrics and source code attributes employed, even in terms of the ISO/IEC-9126 characteristics to be assessed. We applied the methodology to two case studies, involving five open source and one proprietary system. Results demonstrated that the methodology can capture software quality trends and express expert perceptions concerning system quality in a quantitative and systematic manner.

FINDbase: a worldwide database for genetic variation allele frequencies updated

Frequency of INherited Disorders database (FIND base; http://www.findbase.org) records frequencies of causative genetic variations worldwide. Database records include the population and ethnic group or geographical region, the disorder name and the related gene, accompanied by links to any related external resources and the genetic variation together with its frequency in that population. In addition to the regular data content updates, we report the following significant advances: (i) the systematic collection and thorough documentation of population/ethnic group-specific pharmacogenomic markers allele frequencies for 144 markers in 14 genes of pharmacogenomic interest from different classes of drug-metabolizing enzymes and transporters, representing 150 populations and ethnic groups worldwide; (ii) the development of new data querying and visualization tools in the expanded FINDbase data collection, built around Microsoft’s PivotViewer software (http://www.getpivot.com), based on Microsoft Silverlight technology (http://www.silverlight.net) that facilitates querying of large data sets and visualizing the results; and (iii) the establishment of the first database journal, by affiliating FINDbase with Human Genomics and Proteomics, a new open-access scientific journal, which would serve as a prime example of a non-profit model for sustainable database funding.

Compressing biological sequences using self adjusting data structures

In this paper, we investigate experimentally the exploitation of self adjusting data structures for compressing biological sequences. We have evaluated the practical performance of splay tree alternates in comparison with the original version of splay trees. In this investigation, we utilize plain splay trees, a log log n-competitive variation, and a randomized version of splay trees. It is experimentally observed that the compression achieved in the case of the log log n-competitive technique is, as expected, more efficient than the one of the plain splay trees.

Exposing click-fraud using a burst detection algorithm

The explosive growth in the size and use of the World Wide Web continuously creates new great challenges and needs. One such need is dealing with click fraud, which aims at increasing clicks on certain ads and thus the profit of the websites which display them. In this work, we extend the concept of click fraud and redefine it as any pattern of clicks whose goal is to alternate the normal operation of a website in order to produce specific results. An indication of a click fraud may be a burst of clicks that can be simulated by an automated program or script. We deal with the problem of efficient real-time Click Fraud detection utilizing advanced data structures and exploiting their advantages concerning space and time required.

Code4Thought Project: Employing the ISO/IEC-9126 Standard for Software Engineering-Product Quality Assessment

The aim of the Code4Thought project was to deliver a tool supported methodology that would facilitate the evaluation of a software products quality according toISO/IEC-9126 software engineering quality standard. It was a joint collaboration between Dynacomp S.A. and the Laboratory for Graphics, Multimedia and GIS of the Department of Computer Engineering and Informatics of the University of Patras. The Code4thought project focused its research on extending the ISO/IEC-9126standard by employing additional metrics and developing new methods for facilitating system evaluators to define their own set of evaluation attributes. Furthermore, to develop innovative and platform-free methods for the extraction of elements and metrics from source code data.Finally, to design and implement new data mining algorithms tailored for the analysis of software engineering data.

Splaying for Compression: An Experimental Study

In this paper, we propose novel randomized versions of the splay trees. We have evaluated the practical performance of these structures in comparison with the original version of splay trees and with their loglogn-competitive variations, in the application field of compression. In order to evaluate performance, we utilize plain splay trees, their loglog n-competitive variations, and our proposed randomized version with the Chain Splay technique to compress data. It is observed in practice, that the compression achieved in the case of the loglog n-competitive technique is, as intuitively expected, more efficient than the one of the plain splay trees.