Towards a complexity turn in border studies? Rückblicke und Ausblicke

Presentation (2019, December)

The Impact of Human Mobility on Edge Data Center Deployment in Urban Environments

in IEEE Global Communications Conference (GLOBECOM), Waikoloa, HI, USA, 2019 (2019, December)

Multi-access Edge Computing (MEC) brings storage and computational capabilities at the edge of the network into so-called Edge Data Centers (EDCs) to better low-latency applications. To this end ... [more ▼]

Multi-access Edge Computing (MEC) brings storage and computational capabilities at the edge of the network into so-called Edge Data Centers (EDCs) to better low-latency applications. To this end, effective placement of EDCs in urban environments is key for proper load balance and to minimize outages. In this paper, we specifically tackle this problem. To fully understand how the computational demand of EDCs varies, it is fundamental to analyze the complex dynamics of cities. Our work takes into account the mobility of citizens and their spatial patterns to estimate the optimal placement of MEC EDCs in urban environments in order to minimize outages. To this end, we propose and compare two heuristics. In particular, we present the mobility-aware deployment algorithm (MDA) that outperforms approaches that do not consider citizens mobility. Simulations are conducted in Luxembourg City by extending the CrowdSenSim simulator and show that efficient EDCs placement significantly reduces outages. [less ▲]

Linear system identification from ensemble snapshot observations

in Proceedings of the IEEE Conference on Decision and Control (2019, December)

Developments in transcriptomics techniques have caused a large demand in tailored computational methods for modelling gene expression dynamics from experimental data. Recently, so-called single-cell ... [more ▼]

Developments in transcriptomics techniques have caused a large demand in tailored computational methods for modelling gene expression dynamics from experimental data. Recently, so-called single-cell experiments have revolutionised genetic studies. These experiments yield gene expression data in single cell resolution for a large number of cells at a time. However, the cells are destroyed in the measurement process, and so the data consist of snapshots of an ensemble evolving over time, instead of time series. The problem studied in this article is how such data can be used in modelling gene regulatory dynamics. Two different paradigms are studied for linear system identification. The first is based on tracking the evolution of the distribution of cells over time. The second is based on the so-called pseudotime concept, identifying a common trajectory through the state space, along which cells propagate with different rates. Therefore, at any given time, the population contains cells in different stages of the trajectory. Resulting methods are compared in numerical experiments. [less ▲]

Managing Strategic Inventories under Investment in Process Improvement

in European Journal of Operational Research (2019), 279(3), 782-794

In supplier-retailer interactions, the retailer may carry inventories strategically as a bargaining mechanism to induce the supplier to drop the future wholesale price. As per Anand, Anupindi, and Bassok ... [more ▼]

In supplier-retailer interactions, the retailer may carry inventories strategically as a bargaining mechanism to induce the supplier to drop the future wholesale price. As per Anand, Anupindi, and Bassok (2008), the introduction of strategic inventories always benefits the supplier and possibly also the retailer if the holding cost is sufficiently low (due to the contract-space-expansion effect). Is such a move beneficial for the supply chain agents in the presence of process improvement efforts? Such efforts—initiated by suppliers—ultimately reduce production cost and may translate into lower wholesale prices as well as lower consumer prices. We find that strategic inventories may stimulate investment in process improvement when the holding cost is high (as it encourages the supplier to further reduce future cost to eliminate the need for strategic inventories), but may suppress such investment when the holding cost is low (as strategic inventories are cheap to stock and hence cannot be eliminated). Our key result, contrary to the existing literature, is that strategic inventories may be harmful to both supply chain agents in the presence of process improvement. In that case, the supplier effectively over-invests in process improvement efforts, inducing the retailer to reduce the stock of strategic inventories, while reversing the benefits of the contract-space-expansion effect. We also consider variations to the model, whereby the supplier may delay his investment decision, the holding cost may be a function of the wholesale price set by the supplier, consumers may behave strategically, and the planning horizon may consist of multiple periods. [less ▲]

Conference 'SL2R Days'

Report (2019)

EU-ASEAN High Performance Computing (HPC) Study Expert Mapping of ASEAN policy orientations and related HPC research infrastructures

Report (2019)

Le concept russe de « guerre nouvelle génération » du Général Gerasimov : quelle exploitation pour l’armée de Terre ?

Report (2019)

A l’instar du moteur ayant permis de rétablir le mouvement en 1940 après la paralysie opérée par le feu en 1914, la doctrine russe formulée autour du document cadre de 2014 et des discours du Général ... [more ▼]

A l’instar du moteur ayant permis de rétablir le mouvement en 1940 après la paralysie opérée par le feu en 1914, la doctrine russe formulée autour du document cadre de 2014 et des discours du Général Gerasimov permet en s’adaptant à la donne sociologique et technologique contemporaine de rétablir une liberté d’action et de conduire avec succès une bataille malgré la menace du feu nucléaire, permettant une atteinte rapide des buts de guerre (tout en prévenant l’escalade). Cette doctrine de guerre nouvelle génération fondée en réaction à la guerre hybride américaine et intériorisant les grandes tendances d’évolutions capacitaires, constitue une énième mutation de la guerre par fondation d’une stratégie intégrale dont l’originalité repose sur un emploi coordonné de moyens de toute nature (civils, techniques) et pour les moyens militaires, sur un appareil conventionnel modernisé et infovalorisé. Les modalités opérationnelles qui en découlent recouvrent alors quatre domaines :  L’intégration multi-domaines pour la réalisation de frappes en profondeur dans l’ensemble de l’épaisseur du système ennemi (au sens large), notamment par un usage d’opérations couplées (actions non-linéaires/actions conventionnelles) ;  La fondation d’une architecture C4ISR complète permettant de basculer du combat collaboratif aux opérations collaboratives dans la profondeur ;  Le retour de la menace d’ADM tactiques et le développement d’une capacité de dissuasion conventionnelle par acquisition de moyens à « efficience nucléaire » ;  La centralité des capacités robotiques et notamment leur massification tactique pour produire des effets de saturation à faibles coûts. Ainsi, est mis en exergue un modèle d’opérations privilégiant les actions coordonnées sur l’ensemble des capacités ennemis (population, économie, structures civiles) en usant de la totalité des fonctions disponibles (champs immatériels de désinformation, cyber, proxies, etc. et également champs matériels de frappes en profondeur) pour produire des effets tactiques et opérationnels suffisant pour paralyser la capacité de réaction ennemie. Modèle qui n’est que partiellement compatible avec la conception française de la guerre, puisque faisant fi du respect du droit international et ne prenant pas en compte le cas d’opérations défensives. Par conséquent les enseignements que l’adT peut tirer de la doctrine russe, aussi bien en offensive qu’en défensive, sont centrés sur les voies et moyens d’une action coordonnée de l’ensemble des domaines de la lutte dans le cadre d’opérations dans la profondeur et ce sur l’ensemble du spectre des engagements ; des OPEX à la haute intensité. [less ▲]

On the Formal Structure of Rules in Conflict of Laws

in Legal Knowledge and Information Systems 2019 (proceedings) (2019, December)

Law has different methods and principles to resolve conflicts between norms, most of these come from Roman Law, they are well-known and much discussed. There is a whole branch of law, though, which is ... [more ▼]

Law has different methods and principles to resolve conflicts between norms, most of these come from Roman Law, they are well-known and much discussed. There is a whole branch of law, though, which is much less discussed while having been created exactly in order to resolve special conflicts: conflict of laws. This system within Private International Law is dedicated to providing metarules in legal situations where more than one national legal systems’ rules could be applied: CoL rules indirectly settle the situation by declaring which one’s should. The formal representation of how these rules work contributes not only to the modelling of this branch of law but also provides methodologies for concerns arising from other conflicting normative systems, such as ethically sensitive situations where there are multiple stakeholders with different moral backgrounds. [less ▲]

Automatic Software Tuning of Parallel Programs for Energy-Aware Executions

in Proc. of 13th Intl. Conf. on Parallel Processing and Applied Mathematics (PPAM 2019) (2019, December)

For large scale systems, such as data centers, energy efficiency has proven to be key for reducing capital, operational expenses and environmental impact. Power drainage of a system is closely related to ... [more ▼]

For large scale systems, such as data centers, energy efficiency has proven to be key for reducing capital, operational expenses and environmental impact. Power drainage of a system is closely related to the type and characteristics of workload that the device is running. For this reason, this paper presents an automatic software tuning method for parallel program generation able to adapt and exploit the hardware features available on a target computing system such as an HPC facility or a cloud system in a better way than traditional compiler infrastructures. We propose a search based approach combining both exact methods and approximated heuristics evolving programs in order to find optimized configurations relying on an ever-increasing number of tunable knobs i.e., code transformation and execution options (such as the num- ber of OpenMP threads and/or the CPU frequency settings). The main objective is to outperform the configurations generated by traditional compiling infrastructures for selected KPIs i.e., performance, energy and power usage (for both for the CPU and DRAM), as well as the runtime. First experimental results tied to the local optimization phase of the proposed framework are encouraging, demonstrating between 8% and 41% improvement for all considered metrics on a reference benchmark- ing application (i.e., Linpack). This brings novel perspectives for the global optimization step currently under investigation within the presented framework, with the ambition to pave the way toward automatic tuning of energy-aware applications beyond the performance of the current state-of-the-art compiler infrastructures. [less ▲]

International Law and the Protection of Children Associated with Armed Forces and Armed Groups: Reconciling Normative Standards on Recruitment and Participation

Scientific Conference (2019, December)