Maria Carla Calzarossa

• Professor (Full) at University of Pavia

Several explainable AI methods are available, but there is a lack of a systematic comparison of such methods. This paper contributes in this direction, by providing a framework for comparing alternative explanations in terms of complexity and robustness. We exemplify our proposal on a real case study in the cybersecurity domain, namely, phishing we...

The pervasiveness of IoT devices in many real-world domains, such as healthcare, agriculture, manufacturing, transportation, offers new interesting opportunities, but at the same time opens new challenges. In fact, to ensure the effectiveness of the innovative smart applications being deployed nowadays in these ecosystems, the mapping between appli...

Modern IoT ecosystems face many security issues. An aspect often neglected concerns covert channels, which allow for exfiltrating data or preventing detection. To this aim, the Message Queuing Telemetry Transport (MQTT) protocol can be abused to create various hidden communication paths, mainly due to its textual nature. Alas, simpler detection met...

Virtualization and server consolidation are the technologies that govern today’s data centers, allowing both efficient management at the functionality level as well as at the energy and performance levels. There are two main ways to virtualize either using virtual machines or containers. Both have a series of characteristics and applications, somet...

Phishing is a fraudulent practice aimed at convincing individuals to reveal sensitive information, such as account credentials or credit card details, by clicking the links of malicious websites. To reduce the impacts of phishing, the timely identification of these websites is essential. For this purpose, machine learning models are often devised....

Phishing is a very dangerous security threat that affects individuals as well as companies and organizations. To fight the risks associated with this threat, it is important to detect phishing websites in a timely manner. Machine learning models work well for this purpose as they can predict phishing cases, using information on the underlying websi...

The pervasiveness of complex technological infrastructures and services coupled with the continuously evolving threat landscape poses new sophisticated security risks. These risks are mostly associated with many diverse vulnerabilities related to software or hardware security flaws, misconfigurations and operational weaknesses. In this scenario, a...

Phishing is a security threat with serious effects on individuals as well as on the targeted brands. Although this threat has been around for quite a long time, it is still very active and successful. In fact, the tactics used by attackers have been evolving continuously in the years to make the attacks more convincing and effective. In this contex...

Cloud technologies are being used nowadays to cope with the increased computing and storage requirements of services and applications. Nevertheless, decisions about resources to be provisioned and the corresponding scheduling plans are far from being easily made especially because of the variability and uncertainty affecting workload demands as wel...

This book constitutes the post proceedings of the 28th International Symposium on Modelling, Analysis, and Simulation of Computer and Telecommunication Systems, MASCOTS 2020, held online -due to COVID -19- in Nice, France, in November 2020. The 17 full papers presented were carefully reviewed and selected from 124 submissions. The symposium collect...

IoT technologies are becoming pervasive in public and private sectors and represent presently an integral part of our daily life. The advantages offered by these technologies are frequently coupled with serious security issues that are often not properly overseen or even ignored. The IoT threat landscape is extremely wide and complex and involves a...

Cloud computing provides cost‐effective solutions for deploying services and applications. Although resources can be provisioned on demand, they need to adapt quickly and in a seamless way to the workload intensity and characteristics and satisfy at the same time the desired performance levels. In this paper, we evaluate the effects exercised by di...

Among the most important reasons why people communicate with each other is to share and support each other through emotional problems, yet most online social systems are uncomfortable or unsafe spaces for this purpose. This has led to the development of online emotional support systems, where users needing to speak to someone can anonymously connec...

The web is a complex information ecosystem that provides a large variety of content changing over time as a consequence of the combined effects of management policies, user interactions and external events. These highly dynamic scenarios challenge technologies dealing with discovery, management and retrieval of web content. In this paper, we addres...

Data parallel applications are being extensively deployed in cloud environments because of the possibility of dynamically provisioning storage and computation resources. To identify cost-effective solutions that satisfy the desired service levels, resource provisioning and scheduling play a critical role. Nevertheless, the unpredictable behavior of...

Parallelism has many advantages in accelerating compute tasks amenable to speed up. However, whereas parallel processing in an elastic, pay-per-use cloud can generate numerous benefits, there's a hidden downside due to the fundamental statistics and interrelationships of tasks whose completion times are stochastic.

Despite the fast evolution of cloud computing, up to now the characterization of cloud workloads has received little attention. Nevertheless, a deep understanding of their properties and behavior is essential for an effective deployment of cloud technologies and for achieving the desired service levels. While the general principles applied to paral...

Workload characterization is a well-established discipline that plays a key role in many performance engineering studies. The large-scale social behavior inherent in the applications and services being deployed nowadays leads to rapid changes in workload intensity and characteristics and opens new challenging management and performance issues. A de...

Internet and online-based social systems are rising as the dominant mode of communication in society. However, the public or semi-private environment under which most online communications operate under do not make them suitable channels for speaking with others about personal or emotional problems. This has led to the emergence of online platforms...

The technologies aimed at Web content discovery, retrieval and management face the compelling need of coping with its highly dynamic nature coupled with complex user interactions. This paper analyzes the temporal patterns of the content changes of three major news websites with the objective of modeling and predicting their dynamics. It has been ob...

News websites are expected to deliver in a timely manner the latest stories as well as their latest developments. Thereby, tools, such as, search engines, need to cope with these rapid and frequent content changes by adjusting their crawling activities accordingly. In this paper we explore and model the properties and temporal behavior of the conte...

The headers used by the various network protocols represent a good source of information for understanding the behavior and the properties of the traffic and detecting potential security attacks. In this paper we present a comprehensive analysis of the usage patterns of the headers included in the HTTP request messages of the clients. Our study sho...

The traffic produced by the periodic crawling activities of Web robots often represents a good fraction of the overall websites traffic, thus causing some non-negligible effects on their performance. Our study focuses on the traffic generated on the SPEC website by many different Web robots, including, among the others, the robots employed by some...

The content of news websites changes frequently and rapidly and its relevance tends to decay with time. To be of any value to the users, tools, such as, search engines, have to cope with the dynamics of websites and detect changes in a timely manner. In this paper we apply time series analysis to study the properties and the temporal patterns of th...

Web robots periodically crawl Web sites to download their content, thus producing potential bandwidth overload and performance degradation. To cope with their presence, it is then important to understand and predict their behavior. The analysis of the properties of the traffic generated by some commercial robots has shown that their access patterns...

This paper presents the main results of an extensive monitoring exercise aimed at assessing the role of informatics education in Italian high schools. The investigation focused on the teaching and certification activities performed by the schools as well as on the role and use of information technologies for teaching and communications with the stu...

Questo articolo presenta i principali risultati di un’indagine condotta nelle Scuole Secondarie di secondo grado di otto Regioni. Allo scopo di ampliare e consolidare i risultati di una precedente indagine rivolta alle Scuole di tre Regioni – Lazio, Lombardia e Puglia – questa nuova indagine, relativa all’anno scolastico 2008-2009, ha coinvolto le...

Questo articolo presenta i principali risultati di un’indagine condotta nel 2010 e rivolta agli studenti delle Scuole Secondarie di secondo grado di alcune Regioni italiane, che durante i propri studi hanno conseguito la certificazione informatica ECDL presso un Test Center di una Scuola. In questa indagine, si è voluto integrare quanto rilevato ne...

Questo articolo presenta i risultati della seconda rilevazione condotta dall’Osservatorio su Formazione e Certificazione Informatica sulla diffusione delle attività di formazione e certificazione informatica nelle Scuole Secondarie di secondo grado di otto Regioni italiane, relativamente all’anno scolastico 2008-2009. (see http://osservatorio.conso...

L‘indagine, relativa all'anno solare 2008, ha messo in evidenza alcune interessanti tendenze sia in relazione all'attivazione dei progetti ECDL negli Atenei italiani che per quanto riguarda la loro applicazione all'accreditamento delle abilità informatiche di base. Si sono anche notate differenze nelle Facoltà appartenenti alle diverse Aree. Più in...

The evolution of Information and Communication Technology (ICT) has led to the development of Information Society. The Information Society must be built on a foundation in which integrity and rigor for good science promote quality ICT and good ethics will promote good professional practice. These appear to be reasonable causal links but there can b...

The growing amount of information published on the Web, combined with its dynamic nature, opens many challenging issues dealing with management and retrieval of the information and provisioning of the underlying infrastructures. Search engines have to meet two conflicting requirements: minimize the number of downloads and provide up-to-date informa...

Web logs are an important source of information to describe and understand the traffic of the servers and its characteristics. The analysis of these logs is rather challenging because of the large volume of data and the complex relationships hidden in these data. Our investigation focuses on the analysis of the logs of two Web servers and identifie...

This paper presents the main results of two monitoring exercises aimed at analyzing the diffusion of teaching and certification activities of Information and Communication Technologies (ICT) in Italian high schools.

Questo articolo presenta i risultati di una rilevazione statistica e di un insieme di interviste a studenti sul tema della formazione e certificazione informatica nelle scuole superiori di tre regioni: Lazio, Lombardia e Puglia.

Questo articolo presenta i risultati di una rilevazione statistica e di un insieme di interviste a studenti sul tema della formazione e certificazione informatica nelle scuole superiori di tre regioni: Lazio, Lombardia e Puglia.

C. Alfonsi, E. Breno, M. Calzarossa, P. Ciancarini, M. Genoviè, L. Mich, F. Sala, N. Scarabottolo

The Web has become a ubiquitous tool for distributing knowledge and information and for conducting businesses. To exploit the huge potential of the Web as a global information repository, it is necessary to understand its dynamics. These issues are particularly important for news Web sites as they are expected to provide fresh information on curren...

L’articolo presenta i risultati della prima indagine mirata a censire le attività di formazione e certificazione informatica in un universo molto complesso come quello delle Scuole Secondarie di secondo grado. La rilevazione ha coinvolto le Scuole di tre Regioni (Lazio, Lombardia e Puglia) e un campione di studenti con la certificazione ECDL.

ETHICOMP 2008 has the overall theme of “Living, Working and Learning beyond Technology”. In 1995, Rogerson and Bynum wrote, “The information revolution has become a tidal wave that threatens to engulf and change all that humans value. Governments, organisations and individual citizens therefore would make a grave mistake if they view the computer r...

EUCIP is a pan-European qualification scheme for people entering the IT profession and for IT professionals wishing to assess their professional development. This paper presents the experiences of the Italian Universities in the framework of the EUCIP programme. We illustrate both the institutional perspective of the Universities and the personal p...

The European Computer Driving Licence (ECDL) programme aims at testing practical skills and competences in using ICT tools. This paper presents the results of a monitoring exercise aimed at analyzing the impact of the ECDL programme in the Italian Universities. The ECDL programme, adopted in most Italian Universities since the year 2000, has involv...

L’articolo presenta lo stato dei progetti di certificazione delle abilità nell’uso delle tecnologie informatiche svolti dagli Atenei Italiani, evidenziandone gli aspetti salienti, l’evoluzione e le principali linee di tendenza. L’articolo presenta anche il punto di vista di un campione di studenti che hanno ottenuto la certificazione ECDL nel corso...

Sommario Questo articolo presenta i risultati del progetto CampusOne della Conferenza dei Rettori delle Università Italiane (CRUI), con particolare riferimento all'accreditamento delle abilità nell'uso degli strumenti informatici di base. L'articolo analizza il ruolo svolto da CampusOne nella diffusione della certificazione ECDL (European Computer...

Questo articolo presenta i risultati del progetto CampusOne della Conferenza dei Rettori delle Università Italiane (CRUI), con particolare riferimento all'accreditamento delle abilità nell'uso degli strumenti informatici di base. L'articolo analizza il ruolo svolto da CampusOne nella diffusione della certificazione ECDL (European Computer Driving L...

Il presente articolo si propone di fornire una panoramica sul significato complessivo di EUCIP, illustrandone le caratteristiche e le potenzialità non soltanto come strumento di certificazione ma anche come schema di valutazione delle competenze informatiche. L’articolo presenterà inoltre le esperienze maturate nelle Università italiane, focalizzan...

L’articolo discute l’importanza delle competenze e conoscenze informatiche nella formazione universitaria e il ruolo della certificazione di queste competenze. Dopo un esame della situazione italiana riguardo alle competenze informatiche, l’articolo analizza le attività svolte nel recente passato dalle Università e presenta le principali linee evol...

A partire dall’anno 2001, l’Osservatorio delle Certificazioni Informatiche negli Atenei Italiani, patrocinato da AICA e con la collaborazione di CINI e Fondazione CRUI, ha svolto indagini annuali mirate ad analizzare l’introduzione e la diffusione delle certificazioni informatiche nel mondo universitario Italiano, con particolare riferimento alle c...

The performance of HPF codes is influenced by the characteristics of the parallel system and by the efficiency of the compilation system. Performance analysis has to take into account all these aspects. We present the integration of a compilation system with a performance analysis tool aimed at the evaluation of HPF+ codes. The analysis is carried...

We present the results of a monitoring exercise whose objectives were to analyze the experiences of the Italian Universities in the framework of the ECDL programme and to assess the impact of the ECDL certification in the Universities. Our investigation focused on the ECDL projects carried out by 50 Universities in the year 2004. The analysis has s...

We present the results of a monitoring exercise whose objectives were to analyze the experiences of the Italian Universities in the framework of the ECDL programme and to assess the impact of the ECDL certification in the Universities. Our investigation focused on the ECDL projects carried out by 50 Universities in the year 2004. The analysis has s...

Interactive Web services make use of highly dynamic contents. To de-sign efficient mechanisms for the replication and distribution of these contents and to improve the QoS perceived by the users, it is impor-tant to understand how often and to what extent contents change. This paper addresses these issues by studying the dynamic behavior of the con...

Questo documento presenta i risultati sulla diffusione delle certificazioni informatiche negli Atenei Italiani nell’anno solare 2004, con particolare riferimento alle certificazioni supportate da AICA (Associazione Italiana per l’Informatica e il Calcolo Automatico http://www.aicanet.it).

Web pages are created, modified and removed at unspecified times by their owners. The frequency and extent of changes to Web pages vary across sites and across pages within sites. These changes influence the quality of the information retrieved from the Web and to some extent the delays experienced by the users. Our study focuses on the analysis of...

Web sites have become increasingly complex and oer a large variety of services and contents. The proliferation of dynamic Web con- tents opens up new challenging performance and scalability issues. This paper addresses the characterization of dynamic Web contents by study- ing their update process. We identify parameters and metrics that de- scribe...

Electronic mail is the core of modern communications. People rely on email to conduct their business and stay in touch with families and friends. The ubiquity and popularity of email make its QoS an important issue. Performance of mail systems is the result of the interactions between their hardware and software components and the user behavior, th...

Tuning and debugging the performance of parallel applications is an iterative process consisting of several steps dealing with identification and localization of inefficiencies, repair, and verification of the achieved performance. In this paper, we address the analysis of the performance of parallel applications from a methodological viewpoint wit...

Performance evaluation studies are to be an integral part of the design and tuning of parallel applications. Their structure and their behavior are the dominating factors. We propose a hierarchical approach to the systematic characterization of the workload of a parallel system, to be kept as modular and flexible as possible. The methodology is bas...

Al fine di analizzare l’introduzione e l’impatto dell’ECDL negli Atenei, l’AICA ha stipulato un accordo di collaborazione con il CINI (Consorzio Interuniversitario Nazionale per l’Informatica) che prevede la partecipazione della Fondazione CRUI. Nell’ambito di tale accordo opera una Commissione, presieduta dalla Prof. M. Calzarossa dell’Università...

The fast technological evolution and the convergence of fixed and mobile communication infrastructures have led to the realization of a large variety of innovative applications and services that have become an integral part of our society. Efficiency, reliability, availability and security, i.e., quality of service, are fundamental requirements for...

Parallel programs experience performance inefficiencies as a result of dependencies, resource contentions, uneven work distributions and loss of synchronizations among processors. The analysis of these inefficiencies is very important for tuning and performance debugging studies. In this paper we address the identification and localization of perfo...

Electronic mail is the core of modern communications. People rely on email to conduct their business and stay in touch with families and friends. The ubiquity and popularity of email make its QoS an important issue. Performance of mail systems is the result of the interactions between their hardware and software components and the user behavior, th...

G-Networks: Multiple Classes of Positive Customers, Signals, and Product Form Results.- Spectral Expansion Solutions for Markov-Modulated Queues.- M/G/1-Type Markov Processes: A Tutorial.- An Algorithmic Approach to Stochastic Bounds.- Dynamic Scheduling via Polymatroid Optimization.- Workload Modeling for Performance Evaluation.- Capacity Planning...

High-performance computing (HPC) programmers utilize tracefiles, which record program behavior in great detail, as the basis for many performance analysis activities. The lack of generally accessible tracefiles has forced programmers to develop their own testbeds in order to study the basic performance characteristics of the platforms they use. Sin...

Electronic mail has become an integral part of our daily lives. With this trend, mail servers have to provide a fast, highly available, reliable and secure service. Hence, workload characterization and performance evaluation of mail servers are to be addressed as primary issues. This paper deals with a detailed characterization of mail server workl...

Tracefiles provide a convenient record of the behavior of HPC programs, but are not generally archived because of their storage requirements. This has hin- dered the developers of performance analysis tools, who must create their own tracefile collections in order to test tool functionality and usability. This paper describes a shared databank wher...

The performance of High Performance Fortran (HPF) applications depends on their inherent parallelism and on the strategies adopted by compilers to distribute work and data among the processors. The evaluation of the performance of these applications has to consider all the aspects which in different ways determine such performance. The experimental...

The performance of any type of system cannot be determined without knowing the workload, that is, the requests being processed. Workload characterization consists of a description of the workload by means of quantitative parameters and functions; the objective is to derive a model able to show, capture, and reproduce the behavior of the workload an...

Loops represent the core of most applications in that they contain the bulk of the computations. An efficient parallelization of loops leads to good overall performance of the applications. High Performance Fortran provides a set of directives to be used to exploit the potential parallelism of the code. Our studies focus on the analysis of the perf...

Although the performance of a system is determined by the characteristics of the load being processed, much more care is usually devoted to the construction of a detailed system model than to an accurate definition of the workload model. A precise description of actual workloads is obtained with multiclass workload models. Major difficulties on the...

. The performance of HPF codes is influenced by the characteristics of the parallel system and by the efficiency of the compilation system. Performance analysis has to take into account all these aspects. We present the integration of a compilation system with a performance analysis tool aimed at the evaluation of HPF+ codes. The analysis is carrie...

The performance of parallel programs is influenced by the multiplicity of hardware and software components involved in their executions. Experimental approaches, where trace files collected at run-time by monitors are the basis of the analyses, allow a detailed evaluation of the performance. Quantitative as well as qualitative information related t...

Performance evaluation studies are to be an integral part of the design and tuning of parallel applications. Their structure and their behavior are the dominating factors. We propose a hierarchical approach to the systematic characterization of the workload of a parallel system, to be kept as modular and flexible as possible. The methodology is bas...