Binary blended cement pastes and concrete using gravel wash mud (GWM) powders

in Construction and Building Materials (2021)

Machine learning in mix design of Miscanthus lightweight concrete

in Construction and Building Materials (2021)

Review of Adam Crymble: Technology and the Historian. Transformations in the Digital Age

in H-Soz-Kult: Kommunikation und Fachinformation für die Geschichtswissenschaften (2021)

Web Archives of the COVID Crisis: Digital Voices, Preservation and Loss

Presentation (2021, September 16)

This roundtable, which is organized by the WARCnet network and chaired by Valérie Schafer (C2DH, University of Luxembourg), aims to shed light on the issues, challenges, values and limits of web archiving ... [more ▼]

This roundtable, which is organized by the WARCnet network and chaired by Valérie Schafer (C2DH, University of Luxembourg), aims to shed light on the issues, challenges, values and limits of web archiving during the COVID crisis. It will combine analysis by web archivists and scholars and entwine analysis of web archiving practices and preserved web content, in order to address several key issues related to the conference, such as the “silences” and “noises” of these archives. The first part of the roundtable will focus on web archives collections that have been created during the COVID-19 crisis by many institutions throughout Europe. Friedel Geeraert (The State Archives of Belgium and the Royal Library of Belgium) will provide a short comparative overview of the strategies of web archiving institutions in Europe, that the team documented through an oral history campaign, while Nicola Bingham (The British Library, UK) will offer more precise overviews of the collections that were gathered respectively by the UK Web Archive and the IIPC (International Internet Preservation Consortium). Claude Mussou (Ina THEQUE, France) will explore the archiving of Twitter at the Institut national de l’audiovisuel (France). Niels Brügger (Aarhus University, Denmark) and Jane Winters (SAS, University of London) will then discuss memories and heritage of the COVID-crisis through the lens of these web archives. Finally the last part will focus on research approaches, notably close and distant reading, and the collective and individual traces, social and political expressions at stake in these web archives: Valérie Schafer will comment on the distant reading approach within these archives. Sophie Gebeil (Aix-Marseille University, France) will underline issues related to “carers” and social struggles. Valérie Schafer will also briefly mention the gendered approach of the COVID crisis that the working group is currently conducting. This roundtable will be followed by a discussion with the audience in order to deepen the topics that are at the core of the conference, whether it be loss, preservation, the political “we”, feelings, etc. [less ▲]

Analysis and Probing of Parallel Channels in the Lightning Network

E-print/Working paper (2021)

Bitcoin can process only a few transactions per second, which is insufficient for a global payment network. The Lightning Network (LN) aims to address this challenge. The LN allows for low-latency bitcoin ... [more ▼]

Bitcoin can process only a few transactions per second, which is insufficient for a global payment network. The Lightning Network (LN) aims to address this challenge. The LN allows for low-latency bitcoin transfers through a network of payment channels. In contrast to regular Bitcoin transactions, payments in the LN are not globally broadcast. Thus it may improve not only Bitcoin's scalability but also privacy. However, the probing attack allows an adversary to discover channel balances, threatening users' privacy. Prior work on probing did not account for the possibility of multiple (parallel) channels between two nodes. Naive probing algorithms yield false results for parallel channels. In this work, we develop a new probing model that accurately accounts for parallel channels. We describe jamming-enhanced probing that allows for full balance information extraction in multi-channel hops, which was impossible with earlier probing methods. We quantify the attacker's information gain and propose an optimized algorithm for choosing probe amounts for N-channel hops. We demonstrate its efficiency based on real-world data using our own probing-focused LN simulator. Finally, we discuss countermeasures such as new forwarding strategies, intra-hop payment split, rebalancing, and unannounced channels. [less ▲]

Nonequilibrium thermodynamics of light-induced reactions

in Journal of Chemical Physics (2021), 155

Current formulations of nonequilibrium thermodynamics of open chemical reaction networks only consider chemostats as free-energy sources sustaining nonequilibrium behaviors. Here, we extend the theory to ... [more ▼]

Current formulations of nonequilibrium thermodynamics of open chemical reaction networks only consider chemostats as free-energy sources sustaining nonequilibrium behaviors. Here, we extend the theory to include incoherent light as a source of free energy. We do so by relying on a local equilibrium assumption to derive the chemical potential of photons relative to the system they interact with. This allows us to identify the thermodynamic potential and the thermodynamic forces driving light-reacting chemical systems out-of-equilibrium. We use this framework to treat two paradigmatic photochemical mechanisms describing light-induced unimolecular reactions—namely, the adiabatic and diabatic mechanisms—and highlight the different thermodynamics they lead to. Furthermore, using a thermodynamic coarse-graining procedure, we express our findings in terms of commonly measured experimental quantities, such as quantum yields. [less ▲]

Verification of design models of cyber-physical systems specified in Simulink

Doctoral thesis (2021)

Recent advances in cyber-physical systems (CPS) have allowed highly available and approachable technologies with interconnected systems between the physical assets and the computational software ... [more ▼]

Recent advances in cyber-physical systems (CPS) have allowed highly available and approachable technologies with interconnected systems between the physical assets and the computational software components. This has resulted in more complex systems with wider capabilities. For example, they can be applied in various domains such as safe transport, efficient medical devices, integrated systems, critical infrastructure control and more. The development of such critical systems requires advanced new models, algorithms, methods and tools to verify and validate the software components and the entire system. The verification of cyber-physical systems has become challenging: (1) The complex and dynamical behaviour of systems requires resilient automated monitors and test oracles that can cope with time-varying variables of CPS. (2) Given the wide range of existing verification and testing techniques from formal to empirical methods, there is no clear guidance as to how different techniques fare in the context of CPS. (3) Due to serious issues when applying exhaustive verification to complex systems, a common practice is needed to verify system components separately. This requires adding implicit assumptions about the operational environment of system components to ensure correct verification. However, identifying environment assumptions for cyber-physical systems with complex, mathematical behaviors is not trivial. In this dissertation, we focus on addressing these challenges. In this dissertation, we propose a set of effective approaches to verify design models of CPS. The work presented in this dissertation is motivated by ESAIL maritime micro-satellite system, developed by LuxSpace, a leading provider of space systems, applications and services in Luxembourg. In addition to ESAIL, we use a benchmark of eleven public-domain Simulink models provided by Lockheed Martin, which are representative of different categories of CPS models in the aerospace and defence sector. To address the aforementioned challenges, we propose (1) an automated approach to translate CPS requirements specified in a logic-based language into test oracles specified in Simulink. The generated oracles are able to deal with CPS complex behaviours and interactions with the system environment; (2) An empirical study to evaluate the fault-finding capabilities of model testing and model checking techniques for Simulink models. We also provide a categorization of model types and a set of common logical patterns for CPS requirements; (3) An automated approach to synthesize environment assumptions for a component under analysis by combining search-based testing, machine learning and model checking procedures. We also propose a novel technique to guide the test generation based on the feedback received from the machine learning process; and (4) An extension of (3) to learn more complex assumptions with arithmetic expressions over multiple signals and numerical variables. [less ▲]

QKD parameter estimation by two-universal hashing leads to faster convergence to the asymptotic rate

E-print/Working paper (2021)

This paper proposes and proves security of a QKD protocol which uses two-universal hashing instead of random sampling to estimate the number of bit flip and phase flip errors. For this protocol, the ... [more ▼]

This paper proposes and proves security of a QKD protocol which uses two-universal hashing instead of random sampling to estimate the number of bit flip and phase flip errors. For this protocol, the difference between asymptotic and finite key rate decreases with the number $n$ of qubits as $cn^{-1}$, where $c$ depends on the security parameter. For comparison, the same difference decreases no faster than $c'n^{-1/3}$ for an optimized protocol that uses random sampling and has the same asymptotic rate, where $c'$ depends on the security parameter and the error rate. [less ▲]

Democracy, Freedom and Truth at a Time of Digital Disruption: An equation with three unknowns?

in IntechOpen (2021)

The pattern of a knowledge-based society relies to a large extent on digital technologies and intangible outputs and generate considerable transnational financial flows and gains. These technologies also ... [more ▼]

The pattern of a knowledge-based society relies to a large extent on digital technologies and intangible outputs and generate considerable transnational financial flows and gains. These technologies also play a key role in providing free access to data and information, encouraging citizen participation in public decision-making, fostering transparency and scrutiny of government action and mobilising new players capable of identifying alternative means of civic and political participation worldwide. At the same time, the increasingly impact of online platforms in manipulating transnational public debates, and the surge in extremist groups using the digital ecosystem to incite hatred, hostility and violence are a warning sign that these modes of communication may be having an adverse effect on democracy and that the boundary between fact and fiction is not as clear as we may like to think. The US presidential election campaign and the Brexit referendum (2016), the theories about COVID-19 (that have flooded the web since 2019), the terrorist attack against French teacher Samuel Paty (16 October 2020) all highlight these trends. When the majority of the world’s citizens are using online media as their main source of information, the proliferation of disinformation and the related threat of radicalism and extremism have led to a growing awareness of these issues at international- and European Union level. What can be done to tackle the situation? How should the democratic states with new forms of private power in the algorithmic society? Where should the line be drawn between freedom of expression and media pluralism on the one hand, and intrusion and censorship of dissenting opinions on the other? How should information be defended as a fundamental right? Is there a moral or ethical code when it comes to information? How can be created an environment that is conducive to inclusive, pluralistic public debate? How to equip citizens to develop a critical approach and to take informed decisions? How to balance innovation with the need to ensure transparency and fairness? Could we be witnessing a situation in which algorithms are “dissolving” democracy? Drawing on the archives of the international and European multilateral organisations (UN/UNESCO, Council of Europe, the Organisation for Security and Cooperation in Europe, the European Union) and several public and private stakeholders worldwide, this chapter proposes: a) to take stock of the issues and challenges raised by the proliferation of fake news, social media and algorithms, and their impact on freedom and democracy; b) to review the regulatory provisions implemented in this area at European and international level; and c) to identify future prospects. [less ▲]

La cybersecurity come bene pubblico: alcune riflessioni normative a partire dai recenti sviluppi nel diritto UE

in Federalismi.it (2021), 21

The article casts the light on how and to what extent the recent EU legislative developments can uphold the thesis that would identify cybersecurity as a public good, in particular, taking into account ... [more ▼]

The article casts the light on how and to what extent the recent EU legislative developments can uphold the thesis that would identify cybersecurity as a public good, in particular, taking into account systems’ robustness. The doctrine of the public good, which is typically an economic concept, in its normative dimension reveals a framework of shared responsibilities, in view of the common interest in having a satisfactory level of security of the information systems at the basis of our societies. Improving cybersecurity is essential, on the one hand, to trust and benefit from innovation, connectivity and automation; on the other hand, for safeguarding fundamental rights and freedoms, including the rights to privacy and to the protection of personal data, and the freedom of expression and information. Against this background, the new strategy of the European Commission on cybersecurity, the proposal for an NIS 2.0 Directive and, at a lower level of abstraction, the inclusion of minimum cybersecurity requirements for connected devices in the Directives and Regulations of the “New Legislative Framework” (NLF), testify the firm will of the Commission to outline a clear, coherent and inclusive regulatory framework, in order to increase the global level of security within the Union. [less ▲]