1,720,973 research outputs found
An assessment framework for explainable AI with applications to cybersecurity
No full textSeveral 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 website detection. In fact, in this domain explainability is a compelling issue because of its potential benefits for the detection of fraudulent attacks and for the design of efficient security defense mechanisms. For this purpose, we apply our methodology to the machine learning models obtained by analyzing a publicly available dataset containing features extracted from malicious and legitimate web pages. The experiments show that our methodology is quite effective in selecting the explainability method which is, at the same time, less complex and more robust
Workflow Scheduling in the Cloud-Edge Continuum
No full textScheduling in the cloud-edge continuum is a challenging problem. In
fact, scheduling has to cope with the peculiarities of these complex ecosystems
and satisfy at the same time the desired service levels. In this paper, we investigate
the benefits of the cloud-edge continuum for deploying workflows with different
characteristics, e.g., computation or communication-intensive. In detail, we formulate a multi-objective optimization problem solved using a Genetic Algorithm.
This problem is aimed at identifying the scheduling plans that minimize two conflicting objectives, namely, the expected workflow execution time and monetary
cost associated with the cloud and edge resources to be provisioned. Our experiments have shown that the plans that exploit both cloud and edge resources represent a good tradeoff between the two objectives. In addition, the workflow characteristics strongly influence these plans. Similarly, the uncertainties that might
affect the infrastructure performance are responsible of significant changes in the
corresponding Pareto fronts
Mitigation of Covert Communications in MQTT Topics Through Small Language Models
No full textModern 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 metrics could be ineffective and their optimization requires a vast number of test cases. Therefore, this paper proposes to use a small language model trained over real MQTT topics to automatically generate the required test cases. Results indicate the need for optimizations to make popular detection metrics usable 'in the wild'
Application Placement in the Cloud Continuum With Resource Overbooking
No full textThe 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 applications and resources of the cloud continuum plays a key role. In this context, we propose a lightweight placement policy aimed at minimizing the network delays experienced by IoT applications by fully exploiting the resources of the cloud continuum. For this purpose, our heuristic tries to allocate application modules as close as possible to their data sources. In addition, by introducing the concept of resource overbooking, a module can be allocated to a resource even if the desired processing capacity of the module exceeds to some extent the available processing capacity of the resource. The results of the extensive simulation experiments have clearly demonstrated the benefits of our policy. For example, as the overbooking factor increases, the network delay tends to decrease even significantly. In contrast, the potential contentions caused by resource overbooking introduce a slight increase in the processing time although it does not generally exceed the desired processing time of the applications, thus ensuring their QoS requirements
Multi-Objective Optimization of Deadline and Budget-Aware Workflow Scheduling in Uncertain Clouds
Full text linkCloud 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 well as technological infrastructure performance. In this paper we address these issues by formulating a multi-objective constrained optimization problem aimed at identifying the optimal scheduling plans for scientific workflows to be deployed in uncertain cloud environments. In particular, we focus on minimizing the expected workflow execution time and monetary cost under probabilistic constraints on deadline and budget. According to the proposed approach, this problem is solved offline, that is, prior to workflow execution, with the intention of allowing cloud users to choose the plan of the Pareto optimal set satisfying their requirements and preferences. The analysis of the combined effects of cloud uncertainty and probabilistic constraints has shown that the solutions of the optimization problem are strongly affected by uncertainty. Hence, to properly provision cloud resources, it is compelling to precisely quantify uncertainty and take explicitly into account its effects in the decision process
Multivariate analysis of Web content changes
No full textNews 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 content changes of
three major news websites. The dynamics of the changes is
characterized by large fluctuations and significant differences
from day to day and from hour to hour. However, a certain
degree of similarity in the overall patterns of each website
exists. In particular, the application of multivariate analysis
techniques allows us to identify groups of days with similar
change patterns, thus allowing for the customi
Methodologies for the Parallelization, Performance Evaluation and Scheduling of Applications for the Cloud-Edge Continuum
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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