Digital Holographic Interferometry with CO2 Lasers Applied to Aspheric Space Reflectors Testing

Conference (2013, May)

Digital holographic interferometry at long infrared wavelengths allows monitoring large deformations of space reflectors during vacuum-thermal testing. We present different optical schemes and an ... [more ▼]

Digital holographic interferometry at long infrared wavelengths allows monitoring large deformations of space reflectors during vacuum-thermal testing. We present different optical schemes and an application to the complex case of elliptic reflector. [less ▲]

Contact center as new forms of work organization: the triangular relationship between worker, contact center and contractors and well-being at work

Conference (2013, May)

Purpose The new forms of work organization are characterized by different evolutions: multiple workers status, fragmentation of collective work, etc. Among these evolutions, the triangular relationship ... [more ▼]

Purpose The new forms of work organization are characterized by different evolutions: multiple workers status, fragmentation of collective work, etc. Among these evolutions, the triangular relationship between worker, employer and contractors and the intervention of contractors in work organization (Marchington et al., 2004) may be particularly affecting the well-being of workers. This research focus on contact center as a new form of work organization to investigate the influence of the triangular employment relationship on well-being at work. Methodology A quantitative and qualitative approach was used. A survey based on Job Demand-Resources Model (Bakker, Demerouti & Schaufeli, 2003) was conducted among 400 operators from Belgian contact centers to compare internal, outsourced and external contact centers. Three case studies allowed exploring more deeply the influence of triangular employment relationship on well-being. Finally, focus-groups with unions and management representatives helped us to design some practical recommendations. Results Quantitative results indicate that operators from outsourced and external contact centers have a poorer perception of demands and resources at work. They are consequently more likely to report high levels of perceived stress and burnout and low satisfaction with their work. The case studies give us more information about the role of the strategy and the management style of contact centers in coping with triangular employment relationships. Limitations Beyond this explorative research, quantitative data can be further used in multi-sample modeling approach. Research/Practical Implications Recommendations for well-being at work regarding the triangular employment relationship, on which both employers and unions converge, will be highlighted at the conference. Originality This research combines organizational psychology and management theory. [less ▲]

Transmission of Political-Military Information in Advanced Education: The Examples of the European Security and Defence College and the NATO Defence College

in Studia Diplomatica (2013), 65(4),

Large-scale alignments of quasar polarisations: a detailed study of the spinless-particle scenario

Doctoral thesis (2013)

The main motivation for our work has been a puzzling observation concerning quasars. No one expected the existence of correlations in the polarisation of visible light coming from objects separated by ... [more ▼]

The main motivation for our work has been a puzzling observation concerning quasars. No one expected the existence of correlations in the polarisation of visible light coming from objects separated by gigaparsecs, until they were first reported in the form of a redshift-dependent effect that has become more and more significant with the growth of the data sample. In close connexion with the observational group, we have studied in detail the most widely considered scenario, involving axion-photon mixing in extragalactic magnetic fields. After a systematic investigation, we conclude that it is very unlikely that these observations can be accounted for by axion-like particles, given current data and constraints. We also derive new limits on the parameters describing these particles. This thesis gives in particular a detailed account of the consequences of axion-photon mixing on polarisation, studies the influence of averages over the frequency (including a wave-packet treatment of the mixing), and discusses the consequences of different magnetic-field morphologies. [less ▲]

Efficient database pruning for large-scale cover song recognition

in International Conference on Acoustics, Speech, and Signal Processing (ICASSP) (2013, May)

This paper focuses on cover song recognition over a large dataset, potentially containing millions of songs. At this time, the problem of cover song recognition is still challenging and only few methods ... [more ▼]

This paper focuses on cover song recognition over a large dataset, potentially containing millions of songs. At this time, the problem of cover song recognition is still challenging and only few methods have been proposed on large scale databases. We present an efficient method for quickly extracting a small subset from a large database in which a correspondence to an audio query should be found. We make use of fast rejectors based on independent audio features. Our method mixes independent rejectors together to build composite ones. We evaluate our system with the Million Song Dataset and we present composite rejectors offering a good trade-off between the percentage of pruning and the percentage of loss. [less ▲]

Biotechnology, Controversy, and Policy: Challenges of the Bioeconomy in Latin America

in Technology in Society (2013)

This special issue explores cases from Latin American countries, studied in comparison to global trends in the arenas of public participation, scientific knowledge production, regulation and governance ... [more ▼]

This special issue explores cases from Latin American countries, studied in comparison to global trends in the arenas of public participation, scientific knowledge production, regulation and governance. The authors demonstrate the complexity of these cases, both in terms of regional differences and the different spaces of public, policy, and scientific knowledge production into which such innovations are inserted. The articles are based on rich empirical data collected in Argentina, Brazil, Chile and Paraguay. Authors show that the top-down circulation of policy narratives on biotechnology is challenged, complemented and even partly undermined by local bottom-up dynamics. Conversely, articles also focus on those grassroots dynamics and the ways they are influenced and conditioned by macro-sociological and political economic factors. Lastly, a great deal of attention is paid to the ways states and national actors actively contribute to their own insertion in globalized markets where bioengineered living resources are increasingly tasked with solving the most pressing economic and social issues. We believe that this collection of works challenges scholars, intellectuals, policy-makers and relevant stakeholders to open up their views of biotechnology as a dynamic construct that interacts with local situations in a variety of ways. From a more distanced perspective, the aggregated findings of the contributors to this special issue suggest that the important tasks for scholarly work on bioeconomy today become (1) to observe and critically assess the de-localization and re-localization of the concept of bioeconomy in Latin America where biological resources have become increasingly strategic over the last decades; (2) to analyze the bioeconomy as a site of struggles among countries and/or social groups who articulate strategic visions as part of narrating activities. [less ▲]

Study of interface trap density in a GeSn MOS structure by numerical simulation of the electrical characteristics

Conference (2013, May)

The semiconducting alloy germanium tin (GeSn) is expected to play an important role in the development of high mobility channel materials for next generation CMOS and optoelectronic devices. The two most ... [more ▼]

The semiconducting alloy germanium tin (GeSn) is expected to play an important role in the development of high mobility channel materials for next generation CMOS and optoelectronic devices. The two most interesting features of this material, which is compatible with mainstream Si technology, are its tunable direct band-gap and the possibility to induce strain due to the lattice mismatch with Ge and Si, thereby increasing the holes and electrons mobilities. It has been shown that the interface trap density can be under- or overestimated in Ge-channel MOSFETs when applying conventional measurement techniques such as the conductance method. As this effect is common in low band-gap materials, we expect that it also occurs for GeSn. Following our previous work on metal/GeSn/Ge structures, we have therefore applied our home-built numerical simulation software to a metal/oxide/GeSn MOS structure in order to investigate the result of the presence of such interface states. We discuss possible effects of the interface trap density, interface trap energy and temperature on the electrical characteristics. Successive simulations of both the steady-state and ac small-signal regimes give access to measurable quantities such as the admittance spectrum and the C-V curves. A physical interpretation can be attributed to their variations and an overall comparison can be made with results obtained from equivalent electrical circuit analysis. [less ▲]

Contribution à l'étude des amylases du sorgho et leurs utilisations dans la transformation des produits amylacés

Doctoral thesis (2013)

Les amylases sont des enzymes largement utilisées dans le secteur industriel. Elles occupent d'ailleurs une place primordiale dans le marché mondial des enzymes. Les travaux présentés dans ce manuscrit se ... [more ▼]

Les amylases sont des enzymes largement utilisées dans le secteur industriel. Elles occupent d'ailleurs une place primordiale dans le marché mondial des enzymes. Les travaux présentés dans ce manuscrit se sont intéressés à la production d’amylases à partir d’une source végétale peu coûteuse et disponible, le sorgho et aux possibilités de les utiliser dans la transformation des produits amylacés. Dans la première partie de l’étude, après avoir caractérisé et malté sept variétés de sorgho blanc sélectionné à l’ISRA de Bambey (Sénégal), la meilleure variété, la F-2-20 (sans tanins, faible teneur en composés phénoliques et bonnes activités amylasiques) a été retenue pour la suite de l’étude. Dans la deuxième partie des travaux, les paramètres physico-chimiques tels que le pH optimum, la température optimale et la thermostabilité des amylases (α et β) du malt ont été caractérisés. Les deux amylases ont le même pH optimal 5,5 et la température optimale est de 65 °C pour l’α-amylase et 55 °C pour la β amylase. Par ailleurs, le gène de la β-amylase a été aussi étudié. Les résultats de la troisième partie des travaux ont montré la capacité des amylases du malt de sorgho à être utilisées dans des processus d’hydrolyse d’amidon (maïs et blé) et farines (blé et manioc). L’ajout d’ions calcium n’améliore pas significativement les rendements d’hydrolyse. Enfin, suite aux résultats obtenus, l’hydrolyse a été réalisée à plus grande échelle afin de produire des dextrines de différents DE. Les dextrines ont été analysées chimiquement et physicochimiquement pour déterminer leur composition en oligosaccharides et leurs propriétés physiques en vue de leur application dans les secteurs agroalimentaires. [less ▲]

Demenz im Bilderbuch? Martin Baltscheits "Geschichte vom Fuchs der den Verstand verlor"

Article for general public (2013)

A NEW SIMPLIFIED ANALYTICAL DESIGN METHOD FOR STEEL AND COMPOSITE SWAY FRAMES

in Journal of Constructional Steel Research (2013)

Eurocode 4 is the European design code for composite construction; in its so-called EN 1994-1-1 version, the design of “non-sway buildings” is mainly covered. As a result, EC4 focuses on the check of ... [more ▼]

Eurocode 4 is the European design code for composite construction; in its so-called EN 1994-1-1 version, the design of “non-sway buildings” is mainly covered. As a result, EC4 focuses on the check of structural elements like beams, columns, slabs and joints. However, in the last years, the construction of taller buildings and larger industrial halls without wind bracing systems tends to make global instability a relevant failure mode, which is not well covered by Eurocode 4. Recently, intensive experimental, numerical and theoretical investigations have been carried out at Liège University. The latter aimed at improving the knowledge in the field of sway composite building frames and at developing appropriate design rules. The rotational behavior of the beam-to-column composite joints is one of the key aspects of the problem to which a special attention has been paid. This paper reflects investigations carried out at Liège University on this topic. In particular, an innovative simplified analytical method to predict the ultimate loading factor and the associated collapse mode of both steel and composite frames subjected to static loadings is presented. [less ▲]