Sociality and Self-Organisation in Next-Generation Distributed Environments

Doctoral thesis (2011)

The proliferation of computationally powerful, interconnected devices entails a new generation of networked applications and social utilities characterized by a strong growth in scale and dynamics.<br ... [more ▼]

The proliferation of computationally powerful, interconnected devices entails a new generation of networked applications and social utilities characterized by a strong growth in scale and dynamics.<br />Distributed virtual environments constitute a privileged example, involving a high degree of interactivity as well as tightened constraints and requirements. As a response to these issues, this dissertation explores and substantiates sociality as a fundamental principle both in and for the design of such systems.<br />A specialized, dual peer-to-peer architecture is introduced, combining a highly-structured backbone overlay with a loosely-structured geometric client overlay synergistically complementing each other. To enable a global-scale, single-instanced environment, it is imperative to include as many client-side resources as possible and unburden the backbone. The focus of this dissertation therefore lies upon the latter, geometric overlay.<br />By taking an interdisciplinary perspective and leveraging different aspects of sociality, a series of self-organized approaches addressing major problem areas are proposed: a collaborative filtering mechanism for the handling of information overload created from the soaring amounts of users and objects; a confidentiality framework for the protection of sensitive data more likely exposed due to an increased interactivity; and two resource allocation schemes for fairly distributing surplus capacities in the face of critical regional surges.<br />Detailed evaluations show that these decentralized algorithms operate robustly and effectively, while yielding well-converging results in comparison to optimal, global-knowledge scenarios. [less ▲]

When numbers act as attentional cues: behavioral, EEG and fMRI investigations

Presentation (2011, December 16)

Anaerobic mono-digestion of maize and cellulose at different temperatures and operating modes

Doctoral thesis (2011)

A Multi-objective GRASP Algorithm for Joint Optimization of Energy Consumption and Schedule Length of Precedence-Constrained Applications

in 2011 IEEE Ninth International Conference on Dependable, Autonomic and Secure Computing (DASC) (2011, December 14)

We address the problem of scheduling precedence-constrained scientific applications on a heterogeneous distributed processor system with the twin objectives of minimizing simultaneously energy consumption ... [more ▼]

We address the problem of scheduling precedence-constrained scientific applications on a heterogeneous distributed processor system with the twin objectives of minimizing simultaneously energy consumption and schedule length. Previous research efforts on scheduling have focused on the minimization of a quality of service metric based on the completion time of applications (e.g., the schedule length). Recently, many researchers are working on the design of new scheduling algorithms that consider the minimization of energy consumption. We report a new scheduling algorithm accounting for both objectives. The new scheduling algorithm is based on a multi-start randomized adaptive search technique (GRASP framework) that adopts Dynamic Voltage Scaling technique to minimize energy consumption. This technique enables processors to operate in different voltage supply levels at the cost of sacrificing clock frequencies. This multiple voltage implies a trade-off between the quality of the schedules and energy consumption. Therefore, the new proposed approach is designed as a multi-objective algorithm that simultaneously optimize both objectives. Simulation results on a set of real-world applications emphasize the robust performance of the proposed approach. [less ▲]

Le Comité Werner: nouvelles archives

in Histoire, Economie et Société (2011), 2011(04), 29-39

Résumé Centrées sur le « plan d’une union économique et monétaire par étapes » présenté publiquement le 8 octobre 1970, les recherches dans le fonds des archives inédites de la familleWerner permettent la ... [more ▼]

Résumé Centrées sur le « plan d’une union économique et monétaire par étapes » présenté publiquement le 8 octobre 1970, les recherches dans le fonds des archives inédites de la familleWerner permettent la mise en lumière tant du déroulement des travaux du comitéWerner, de l’incidence du planWerner sur la poursuite du chemin vers l’Union économique et monétaire, que de la contribution personnelle de son président à l’élaboration de ce rapport, ainsi qu’à l’obtention du compromis politique nécessaire pour faire avance l’Europe. Abstract Research in the Werner family archives, particularly focusing on the plan for the establishment by stages of an economic and monetary union — presented to the public on 8 October 1970 — has shed light on the work of the Werner Committee, the impact of the Werner Plan on progress towards Economic and Monetary Union, the personal contribution of the committee’s chairman in drafting the plan, as well as the securing of the vital political compromise that enabled Europe to move forward. [less ▲]

Analysis of critical transitions in Parkinson's disease

Poster (2011, December 12)

Background Parkinson’s disease is the most common neurodegenerative movement disorder and is clinically characterized by resting tremor, bradykinesia and cogwheel rigidity. The disease affects 1-2% of the ... [more ▼]

Background Parkinson’s disease is the most common neurodegenerative movement disorder and is clinically characterized by resting tremor, bradykinesia and cogwheel rigidity. The disease affects 1-2% of the global population with prevalence in the people above 65 years of age. The main pathological hallmark of Parkinson’s disease is a progressive loss of dopaminergic neurons in the substantia nigra. Therefore, one important challenge is to improve the understanding of regime shifts between health and disease states. Improving predictions of critical transitions triggering the onset of parkinsonian phenotypes could contribute to the improvement of preventive treatments. Methods Based on cellular models, we will use the mathematical concept of critical transitions to create a toolbox for potentially predicting tipping points towards cellular Parkinson’s disease phenotypes, e.g. mitochondrial dysfunction. Experimentally, we will induce and analyze potential critical transitions in the SH-SY5Y cell line. To do this, we will apply Parkinson’s disease relevant chemical and genetic perturbations and analyze multiple scales of the resulting temporal system behavior. We will combine high content imaging with genetic and biochemical data. A significant informatics challenge arises from the aim to perform the analysis of high time-resolved 3D imaging data. We are therefore developing an automated image analysis pipeline that relies on latest technologies and techniques, such as 3D deconvolution and 3D particle tracking. This pipeline will be applied to study parameters, such as mitochondrial dynamics, which include for instance velocity, morphology, and spatial organization. [less ▲]

Le fait générateur de la responsabilité civile des pouvoirs publics en droit luxembourgeois

Doctoral thesis (2011)

Nachhaltige Regionalentwicklung durch energetische Regionalisierung. Entwicklungspfade der und Regions(re)konstruktionen durch Bioenergieerzeugun

Presentation (2011, December 10)

Glory and Hallelujah. Choir Singing for Young at Heart

Scientific Conference (2011, December 08)

Heute ist es gut und morgen schon nicht mehr - Zum Einfluss habitueller Ärgerreaktion auf das Verhalten während organisationaler Veränderung

Doctoral thesis (2011)