EU Executive Discretion and the Limits of Law

Book published by Oxford University Press (in press)

A Methodology for Handling Data Movements by Anticipation: Position Paper

in Euro-Par 2018 Workshops (in press)

The enhanced capabilities of large scale parallel and distributed platforms produce a continuously increasing amount of data which have to be stored, exchanged and used by various tasks allocated on ... [more ▼]

The enhanced capabilities of large scale parallel and distributed platforms produce a continuously increasing amount of data which have to be stored, exchanged and used by various tasks allocated on different nodes of the system. The management of such a huge communication demand is crucial for reaching the best possible performance of the system. Meanwhile, we have to deal with more interferences as the trend is to use a single all-purpose interconnection network whatever the interconnect (tree-based hierarchies or topology-based heterarchies). There are two different types of communications, namely, the flows induced by data exchanges during the computations, and the flows related to Input/Output operations. We propose in this paper a general model for interference-aware scheduling, where explicit communications are replaced by external topological constraints. Specifically, the interferences of both communication types are reduced by adding geometric constraints on the allocation of tasks into machines. The proposed constraints reduce implicitly the data movements by restricting the set of possible allocations for each task. This methodology has been proved to be efficient in a recent study for a restricted interconnection network (a line/ring of processors which is an intermediate between a tree and higher dimensions grids/torus). The obtained results illustrated well the difficulty of the problem even on simple topologies, but also provided a pragmatic greedy solution, which was assessed to be efficient by simulations. We are currently extending this solution for more complex topologies. This work is a position paper which describes the methodology, it does not focus on the solving part. [less ▲]

Using crowdsourced data to explore the linguistic landscape of cities. Results from the participatory research project Lingscape

in Brunn, Stanley; Kehrein, Roland (Eds.) Handbook of the Changing World Language Map (in press)

Case Study: Analysis and Mitigation of a Novel Sandbox-Evasion Technique

in 3rd Central European Cybersecurity Conference (in press)

Malware is one of the most popular cyber-attack methods in the digital world. According to the independent test company AV-TEST, 350,000 new malware samples are created every day. To analyze all samples ... [more ▼]

Malware is one of the most popular cyber-attack methods in the digital world. According to the independent test company AV-TEST, 350,000 new malware samples are created every day. To analyze all samples by hand to discover whether they are malware does not scale, so antivirus companies automate the process e.g., using sand- boxes where samples can be run, observed, and classified. Malware authors are aware of this fact, and try to evade detection. In this paper we describe one of such evasion technique: unprecedented, we discovered it while analyzing a ransomware sample. Analyzed in a Cuckoo Sandbox, the sample was able to avoid triggering malware indicators, thus scoring significantly below the minimum severity level. Here, we discuss what strategy the sample follows to evade the analysis, proposing practical defense methods to nullify, in our turn, the sample’s furtive strategy. [less ▲]

An efficient approach towards the source-target control of Boolean networks

in IEEE/ACM Transactions on Computational Biology and Bioinformatics (in press)

We study the problem of computing a minimal subset of nodes of a given asynchronous Boolean network that need to be perturbed in a single-step to drive its dynamics from an initial state to a target ... [more ▼]

We study the problem of computing a minimal subset of nodes of a given asynchronous Boolean network that need to be perturbed in a single-step to drive its dynamics from an initial state to a target steady state (or attractor), which we call the source-target control of Boolean networks. Due to the phenomenon of state-space explosion, a simple global approach that performs computations on the entire network, may not scale well for large networks. We believe that efficient algorithms for such networks must exploit the structure of the networks together with their dynamics. Taking this view, we derive a decomposition-based solution to the minimal source-target control problem which can be significantly faster than the existing approaches on large networks. We then show that the solution can be further optimised if we take into account appropriate information about the source state. We apply our solutions to both real-life biological networks and randomly generated networks, demonstrating the efficiency and efficacy of our approach. [less ▲]

The Effect of Rating Scale on Response Style: Experimental Evidence for Job Satisfaction

in Journal of Well-Being Assessment (in press)

This paper explores the relationship between rating scales and response style using experimental data from a sample of 1500 households of the Innovation Panel (2008) which is part of the Understanding ... [more ▼]

This paper explores the relationship between rating scales and response style using experimental data from a sample of 1500 households of the Innovation Panel (2008) which is part of the Understanding Society database. Two random groups of individuals are being asked about their level of job satisfaction using a self-assessment questionnaire through two (7 and 11 points) rating options. By comparing the two groups, we explore the effects of the different rating scales on Extreme Response Style (ERS). The experimental design of the data enables us to show that both high and low Extreme Response Style (ERS) are correlated with personal and demographic characteristics. In addition, when comparing the shorter to a longer scale, we show that the survey design may generates tendency to choose responses at the extreme values of the distribution. [less ▲]

A Note on Stein’s Overreaction Puzzle

in Decisions in Economics and Finance (in press)

Recently, Christoffersen et al. (2013) argue that the overreaction puzzle of Stein (1989) can be explained by a variance-dependent pricing kernel. In this note, we challenge this view. Our theoretical ... [more ▼]

Recently, Christoffersen et al. (2013) argue that the overreaction puzzle of Stein (1989) can be explained by a variance-dependent pricing kernel. In this note, we challenge this view. Our theoretical results are in line with their argument that the variance under risk-neutral measure is more persistent than the variance under physical measure due to a negative variance risk premium. But our results do not support their argument that the more persistent variance is able to qualitatively explain Stein’s findings. We show theoretically that the persistence of the volatility cannot amplify the movements of long-term variance to short-term fluctuations in variance, and, therefore, conclude that Stein’s overreaction puzzle is still unsolved. [less ▲]

The Identity Challenge in Finance: From Analogue Identity to Digitized Identification to Digital KYC Utilities

in European Business Organization Law Review (in press)

Can the Plight of the European Banking Structural Reforms be a Blessing in Disguise?

in European Business Organization Law Review (in press)

One of the problems perceived to be at the heart of the global financial crisis was an amalgamation of various commercial and investment banking activities under one entity, as well as the ... [more ▼]

One of the problems perceived to be at the heart of the global financial crisis was an amalgamation of various commercial and investment banking activities under one entity, as well as the interconnectedness of the banking entities with other financial institutions, investment funds, and the shadow banking system. This paper focuses on various measures that aim to structurally separate the banking entities and their core functions from riskier financial activities such as (proprietary) trading or investments in alternative investment funds. Although banking structural reforms in the EU, UK, and the US have taken different forms, their common denominator is the separation of core banking functions from certain trading or securities market activities. Having reviewed the arguments for and against banking structural reforms and their varieties in major jurisdictions, including the EU, UK, US, France, and Germany, the paper argues that a more nuanced approach to introducing such measures at the EU level is warranted. Given the different market structures across the Atlantic and the lack of conclusive evidence on the beneficial impact of banking structural reforms, the paper concludes that the withdrawal of the banking structural reforms proposal by the European Commission has been a prudent move. It seems that in the absence of concrete evidence, experimenting with structural reforms at the Member-State level would be less costly and would provide for opportunities for learning from smaller mistakes that could pave the way for a more optimal approach to introducing banking structural reforms at the European level in the future. [less ▲]

Regional foreign banks and financial inclusion: Evidence from Africa

in Economic Modelling (in press)

Regional foreign banks expanded quickly over the past decade in developing and emerging countries and have a growing influence in banking systems. We question whether the development of African regional ... [more ▼]

Regional foreign banks expanded quickly over the past decade in developing and emerging countries and have a growing influence in banking systems. We question whether the development of African regional foreign banks, also called Pan-African banks, influences financial inclusion of firms and households. To this end, we combine the World Bank Global Findex database and the World Bank Enterprise Surveys with a hand-collected database on the presence of regional foreign banks. We find that Pan-African banks presence increases firms’ access to credit and limited evidence that they favor financial access of the middle class by restoring confidence in banks. We suggest that this impact is related to the adoption of an aggressive strategy aiming at gaining market shares rather than through the exploitation of informational and technological advantages. [less ▲]