Email spam detection : a symbiotic feature selection approach fostered by evolutionary computation

Post-print version (prior to journal publication)The electronic mail (email) is nowadays an essential communication service being widely used by most Internet users. One of the main problems affecting this service is the proliferation of unsolicited messages (usually denoted by spam) which, despite the efforts made by the research community, still remains as an inherent problem affecting this Internet service. In this perspective, this work proposes and explores the concept of a novel symbiotic feature selection approach allowing the exchange of relevant features among distinct collaborating users, in order to improve the behavior of anti-spam filters. For such purpose, several Evolutionary Algorithms (EA) are explored as optimization engines able to enhance feature selection strategies within the anti-spam area. The proposed mechanisms are tested using a realistic incremental retraining evaluation procedure and resorting to a novel corpus based on the well-known Enron datasets mixed with recent spam data. The obtained results show that the proposed symbiotic approach is competitive also having the advantage of preserving end-users privacy.The work of P. Cortez and P. Sousa was funded by FEDER, through the program COMPETE and the Portuguese Foundation for Science and Technology (FCT), within the project FCOMP-01-0124-FEDER-022674

On the Security Cost of Using a Free and Open Source Component in a Proprietary Product

The work presented in this paper is motivated by the need to estimate the security effort of consuming Free and Open Source Software (FOSS) components within a proprietary software supply chain of a large European software vendor. To this extent we have identified three different cost models: centralized (the company checks each component and propagates changes to the different product groups), distributed (each product group is in charge of evaluating and fixing its consumed FOSS components), and hybrid (only the least used components are checked individually by each development team). We investigated publicly available factors (\eg, development activity such as commits, code size, or fraction of code size in different programming languages) to identify which one has the major impact on the security effort of using a FOSS component in a larger software product

Approximation Algorithms for Max-Min Share Allocations of Indivisible Chores and Goods

We consider Max-min Share (MmS) allocations of items both in the case whereitems are goods (positive utility) and when they are chores (negative utility).We show that fair allocations of goods and chores have some fundamentalconnections but differences as well. We prove that like in the case for goods,an MmS allocation does not need to exist for chores and computing an MmSallocation - if it exists - is strongly NP-hard. In view of these non-existenceand complexity results, we present a polynomial-time 2-approximation algorithmfor MmS fairness for chores. We then introduce a new fairness concept calledoptimal MmS that represents the best possible allocation in terms of MmS thatis guaranteed to exist. For both goods and chores, we use connections toparallel machine scheduling to give (1) an exponential-time exact algorithm and(2) a polynomial-time approximation scheme for computing an optimal MmSallocation when the number of agents is fixed

Data Warehouse in der Marktforschung - Analyse von Benutzeraktivitäten in virtuellen Welten

Bei der Online-Marktforschung läßt sich mit Hilfe virtueller 3D-Welten das Konsumentenverhalten beobachten. Da die Struktur der dabei anfallenden Daten multidimensional ist und die marktforschungsrelevanten Anfragen eine hohe OLAP-Affinität aufweisen, wurde hierzu im Rahmen des Forschungsprojekts Benevit ein Data Warehouse konzipiert und realisiert. Im Rahmen einer Standardisierung der Protokollierung von Konsumentenaktivitäten und deren prototypischen Realisierung erwies sich der Data Warehouse/OLAP-Ansatz zur Speicherung, Analyse und Präsentation der Marktforschungsdaten als adäquates Instrumentenbündel