MERLIN: MEasure the Router Level of the INternet

in 7th Euro-NF Conference on Next Generation Internet (2011, June)

The Internet topology discovery has been an extensive research subject those last years. While the raw data is collected using large traceroute campaigns, additional probing and/or extensive computation ... [more ▼]

The Internet topology discovery has been an extensive research subject those last years. While the raw data is collected using large traceroute campaigns, additional probing and/or extensive computation are required to gather subsets of IP addresses into single identifiers cor- responding to routers. This process, known as alias reso- lution, leads to a router level map of the Internet. In this paper, we push further the Internet router level mapping with a new probing tool called MERLIN. MER- L I N is based on mrinfo, a multicast management tool. mrinfo is able to silently collect all IPv4 multicast en- abled interfaces of a router and all its multicast links to- wards its neighbors: it does not need or rely on any alias resolution mechanism. In addition, M E R L I N comes with the advantage of being much more scalable than standard data gathering techniques. In this paper, we deploy and evaluate the performance of MERLIN. We demonstrate that the use of several vantage points is crucial to circum- vent IGMP filtering in order to collect large amounts of routers. We also investigate the completeness of MERLIN by providing a lower bound on the proportion of in- formation that it may miss. Finally, our dataset and the MERLIN implementation are freely available. [less ▲]

A load shedding scheme against both short- and long-term voltage instabilities in the presence of induction motors

in Proceedings of the IEEE Trondheim Power Tech 2011 conference (2011, June)

In the presence of induction motors in loads, long-term voltage instability may result in sharp voltage decreases, once the generators supporting transmission voltages have their field currents limited ... [more ▼]

In the presence of induction motors in loads, long-term voltage instability may result in sharp voltage decreases, once the generators supporting transmission voltages have their field currents limited. Furthermore, after a fault, induction motors may fail re-accelerating and their stalling leads to short-term voltage instability. This paper investigates the ability of the load shedding scheme, previously proposed by the authors, to deal with both short and long-term voltage instabilities. The scheme is distributed with minimal amount of information exchange. It is also shown that the selectivity of this protection scheme can be increased by prioritizing in time the various controllers. Detailed time simulations of a test system are reported. [less ▲]

The Parametrized Diastolic Filling Formalism: Application in the Asklepios Population

in Conference Program ASME 2011 Summer Bioengineering Conference (2011, June)

Performance Monitoring Systems in Healthcare Organizations The Managerial Perception of Uncertainty in Volatile Environments

in IAMB (Ed.) Proceedings of the 10th IAMB Conference - "Management Challenges in Global Economy" (2011, June)

Monitoring performance in healthcare organizations appears evolving drastically over time, due to a continuous search for better quality, efficiency and timeliness. As a result, the usefulness of ... [more ▼]

Monitoring performance in healthcare organizations appears evolving drastically over time, due to a continuous search for better quality, efficiency and timeliness. As a result, the usefulness of traditional management/performance control systems in such organizations is questioned and a focus is then made on the context in which each organization is operating. In a contingent-based perspective, a limited number of qualitative and quantitative empirical studies examine how some major contingent variables (nature of the organization, size, structure…) influence both the managerial decision-making process and the management control process in healthcare organizations. But, while largely integrated in other managerial contexts (Kabwigiri and Van Caillie, 2000), most of them ignore the variable “uncertainty” and how uncertainty is perceived by managers in healthcare organizations. So, the prime interest of our empirical study is to appraise how uncertainty is appraised by managers in volatile environments. To investigate this subject further, we rely on seminal studies that link between the influence of the organizational attributes (structure, size, level of technology), and their effect on the managerial decisions-making (personal profile and perception) of a suitable management control system (MCS). Our methodology rests on a “qualitative comparative approach” of thirty case studies, lead in two heterogeneous environments (Belgium and Lebanon). Such method allows us to validate our theoretical framework with qualitative case studies collected via semi-structured questionnaire. Our findings provide us with a dialogue between a single (in-depth) case study exploring the phenomenon and a qualitative comparative approach. Thus, we gain understanding of the causal mechanisms and processes, as well as of the core determinants of the healthcare managerial adoption of performance monitoring systems (PMS). [less ▲]

Radiation Modeling of a Hydrogen-Fueled Scramjet

in 42nd AIAA Thermophysics Conference 2011, Vol. 3; No AIAA 2011-3769 (2011, June)

With the difficulty and cost of full-scale flight experiments, the design of scramjet engines relies heavily on computational simulations. Radiation may play an important role in wall heating and flow ... [more ▼]

With the difficulty and cost of full-scale flight experiments, the design of scramjet engines relies heavily on computational simulations. Radiation may play an important role in wall heating and flow cooling of scramjets. However, very few studies have focused on such. The present analysis is based on three-dimensional turbulent reacting flow simulations of the HyShot II hydrogen fueled scramjet engine running at flight conditions of Mach 7.4. A one-dimensional Discrete Ordinates Method analysis with a narrow band averaged spectral model is employed to determine wall heating and flow cooling from thermal radiation. The one-dimensional Discrete Ordinates Method is verifi ed against a three-dimensional ray tracing method. The radiative species considered are H2O and OH. The radiative heat flux is on the order of 10 kW/m2, which is 0.1-0.2% of the total convective wall heat flux. Flow cooling due to radiation is found to be on the order of 2 K. Sensitivity analysis shows that radiation is highly dependent on chamber size, temperature, pressure and radiative species mole fraction. Variations in these factors can explain the differences between previous analyses in the literature that studied hypothetical engines and the current work that models an existing scramjet. [less ▲]

Chromatic characterization of urban fragments: Validation of a user-oriented protocol through the study of Hors-Château street (Liège, Belgium)

in Schindler, Verena M.; Cuber, Stefan (Eds.) AIC 2011, Interaction of Colour & Light in the Arts and Sciences, Midterm Meeting of the International Color Association, Zurich, Switzerland, 7-10 June 2011: Book of Abstracts (2011, June)

A growing need for objective assessment of colour has been observed in recent years in the field of urban design. In contrast to other building attributes (shape, size or location), which are easy to ... [more ▼]

A growing need for objective assessment of colour has been observed in recent years in the field of urban design. In contrast to other building attributes (shape, size or location), which are easy to specify, urban design codes generally define expected chromatic attributes of building façades through indirect regulations considering materials. Some municipalities propose colour charts as guidance tools for urban regulation which present some disadvantages. This obvious lack of affordable instruments in a purpose of characterization or regulation was the main motivation of this research. The aim of this paper is to present a user-oriented protocol which can be applied to characterize chromatic attributes of an urban fragment. The challenge is to provide quantitative answers to these two questions: how is colour organized, how does it develop a structure in the city? The main purpose of the research is hence to investigate stable colour typologies within the city; each urban area (historic center, suburban housing district, commercial zone, etc.) being characterized by a specific colour palette. [less ▲]

A new MPC scheme for damping wide-area electromechanical oscillations in power systems

in the 2011 IEEE PES PowerTech (2011, June)

This paper introduces a new Model Predictive Control (MPC) scheme to damp wide-area electromechanical oscillations. The proposed MPC controller, based on a linearized discrete-time state space model ... [more ▼]

This paper introduces a new Model Predictive Control (MPC) scheme to damp wide-area electromechanical oscillations. The proposed MPC controller, based on a linearized discrete-time state space model, calculates the optimal input sequence for local damping controllers over a chosen time horizon by solving a quadratic programming problem. Local controllers considered include: Power Systems Stabilizers (PSSs), Thyristor Controlled Series Compensators (TCSCs) and Static Var Compensators (SVCs). The MPC scheme is realized and tested first in ideal conditions (complete state observability and controllability, neglecting communication and computing delays). Next, the effects of state-estimation errors, computation and communication delays, and of the number and type of available local damping controllers are studied in order to assess the versatility of this scheme. Realistic simulations are carried out using a 16 generators, 70 bus test system. [less ▲]

Un réseau de représentations : Les années de plomb allemandes à l’épreuve d’une lecture non polarisée de l’histoire

in Bertin-Maghit, Jean-Pierre (Ed.) Actes du colloque international "Lorsque Clio s'empare du documentaire" (2011, June)

The history of the representations of RAF terrorism is marked by uncountable instances of recycling, quotation and loan, all of which are corollaries of the « ageing » of images and sounds, as well as of ... [more ▼]

The history of the representations of RAF terrorism is marked by uncountable instances of recycling, quotation and loan, all of which are corollaries of the « ageing » of images and sounds, as well as of the political and aesthetic distancing that this « ageing » implies. This history nevertheless questions the studies which usually define any hybridization of the representations of a historically charged period in terms of temporal evolution. Indeed, the constant use of images and sounds which have come to embody the German years of lead (e.g. the hostage Schleyer posing in front of the RAF logo) in fact appear prematurely, sometimes even simultaneously with the first broadcasting of the non-recycled, quoted or misused audiovisual material. By resolutely rejecting a linear model dependent on temporal evolution, this article aims to trace back the media exposure that favours these multiple uses, in order to demonstrate to what extent the actions of the RAF already partook of a complex network of quotations, reuses and borrowings. [less ▲]

Apprentissage actif par modification de la politique de décision courante

in Sixièmes Journées Francophones de Planification, Décision et Apprentissage pour la conduite de systèmes (JFPDA 2011) (2011, June)

MANUFACTURING OF POROUS PARTS IN 316L STAINLESS STEEL BY 3D-PRINTING: SOME INDUSTRIAL CASE STUDIES

in Proceedings of AEPR’11, 16th European Forum on Rapid Prototyping and Manufacturing (2011, June)

Additive technologies offer the possibilities to build complex geometries with integrated functionalities, specific to target application. 3D-printing of metallic powder is an additive technology ... [more ▼]

Additive technologies offer the possibilities to build complex geometries with integrated functionalities, specific to target application. 3D-printing of metallic powder is an additive technology proceeding in 2 steps: a green part is first built layer by layer by printing a liquid binder on the powder bed, and then green part is debinded and sintered. As sintering occurs separately of shaping process, 3D-printing is one of the only additive techniques able to produce porous parts, as filters or other fluid permeable components. Different porous characteristics can be obtained by playing on process parameters (AEPR2010). Several industrial case studies are presented and detailed here with their specifications and characteristics that have been obtained. [less ▲]

Comparison of Data Transfer Methods between two different meshes

in Proceedings of "IV International Conference on Computational Methods for Coupled Problems in Science and Engineering" (2011, June)

Many problems solved with the finite element method require more than one mesh (i.e. one specific mesh for each Physic or a remeshing is needed). The Data Transfer Method used, has a great importance in ... [more ▼]

Many problems solved with the finite element method require more than one mesh (i.e. one specific mesh for each Physic or a remeshing is needed). The Data Transfer Method used, has a great importance in the capacity to solve the problem and in the reliability of the solution. In general, the data is composed of two kinds of fields (defined thanks to the nodal values or at the integration points). In this paper, the more used Data Transfer Method is compared with the Data Transfer Methods based on a Weak Form (using Mortar Element or Finite Volume). [less ▲]

Use of high strength steel tubular columns in structures: economic study

in Progress in steel and composite structures : ICMS2011, Wroclaw 15-17 June 2011 (2011, June)

In many structures, the use of high strength steel (HSS), i.e. with an elastic strength higher than 460MPa, offers an economical benefit in comparison with normal steel (NS). The reason relies mainly on ... [more ▼]

In many structures, the use of high strength steel (HSS), i.e. with an elastic strength higher than 460MPa, offers an economical benefit in comparison with normal steel (NS). The reason relies mainly on the fact that the cost increases slower than the strength. Moreover, structures using HSS are usually lighter than the ones made of NS leading to a reduction of the costs related to the transportation, fabrication and painting. However, as the stiffness of HSS structures is smaller than the one of NS structures, the second-order effects and, consequently, the serviceability requirements considerably limit the advantages of the use of HSS. The interrelation between the advantages and the drawbacks of HSS leads to the complicate question of knowing whether there is an economic interest of using HSS instead of NS for structural members. This question has not yet been adequately considered in the literature. The present work aims at investigating building frames with steel and/or composite columns (made of circular steel tubes) with the objective of defining the domains where the use of HSS is economically interesting. Two topics will be addressed: (1) to provide a general view of the economic benefit of the use of HSS; (2) to establish the basis for choosing the material (HSS or NS) for framed structures at the pre-design stage. [less ▲]

Wind tunnel experiments on a flapping drone

in Proceedings of the 15th International Forum on Aeroelasticity and Structural Dynamics, IFASD 2011 (2011, May 29)

The motivation for this paper is to obtain a better understanding of the unsteady aerodynamic phenomena involved in flapping wing flight. The work is mainly experimental but also makes use of numerical ... [more ▼]

The motivation for this paper is to obtain a better understanding of the unsteady aerodynamic phenomena involved in flapping wing flight. The work is mainly experimental but also makes use of numerical results obtained from a vortex lattice approach. The flapping of 3D wings produces vortical structures which differ from those produced in 2D flow. It is a phenomenon experienced by any 3D lifting surfaces that are undergoing time dependent motion. In avian flight, it is known that different types of kinematics produce different kinds of vortical wake structures, depending on the wing aspect ratio. Understanding the wake structures and their effects can lead to the optimisation of flapping flight through the manipulation of these unsteady flow features. The objective of this work is to investigate the kinematics of 3D wings along with the evolution of the resulting vortex and wake structures while varying the oscillation parameters. The parameters in question are reduced frequency, flapping and pitching kinematics and wing profiles.The experiments make use of an enhanced version of a dynamically scaled mechanical flapping wing, which is modelled on large migrating birds with simplified kinematics. Pure flapping and combined pitching and flapping are tested in the wind tunnel and simulated at 6.0m/s, 9.4m/s and 14.8m/s.The model is forced to oscillate at four different frequencies. [less ▲]

Zaburzenia przebiegu okresu poporodowego

in Gajewski, Zdzislaw (Ed.) Problemy w rozrodzie bydla - Aktualne poglady. (2011, May 28)

Specific Immuno Extraction Followed by Enzymatic Detection (SIEFED), a new tool to measure active myeloperoxidase in complex media and to screen potential inhibitors of this enzyme.

in The 7th International Human Peroxidase Meeting, 22-25 May 2011, Brussels (2011, May 25)

A method called SIEFED (“Specific Immuno Extraction Followed by Enzymatic Detection”) was developed for the specific measurement of myeloperoxidase (MPO) activity without interference of the sample medium ... [more ▼]

A method called SIEFED (“Specific Immuno Extraction Followed by Enzymatic Detection”) was developed for the specific measurement of myeloperoxidase (MPO) activity without interference of the sample medium. In this method, MPO is first extracted out of aqueous or biological samples by its capture by immobilized anti-MPO antibodies. A washing step then allows to eliminate the solution or biological fluid with interfering materials (proteins, lipids, reducing or oxidizing molecules, ...) and in a last step the activity of MPO bound to its antibodies is measured by using a sensitive detection system containing a fluorogenic substrate, hydrogen peroxide and nitrite as reaction enhancer. SIEFED is a method of choice to measure easily, quantitatively, and specifically the active part of MPO present in biological samples or complex media. Results obtained with this technique applied to biological samples emphasize the importance to distinguish the total MPO concentration of a sample obtained by ELISA from the active part of MPO, which is the real witness of the oxidant potential of the enzyme. SIEFED is also a powerful tool to study compounds or natural extracts that could have an inhibitory effect on the activity of MPO. Since the potential inhibitor is first incubated with the enzyme solution, and further eliminated by washing after the immunocapture of MPO, the tested compound or extract cannot interfere with the chromogenic substrate used to measure the activity of MPO or with products derived from the enzyme activity. Thus, an inhibitory effect could only be attributed to a direct interaction of the tested compound with the enzyme, either on the active site or another key position of the structure. In conclusion, the SIEFED technique opens new perspectives to study pathologies in which the release of active MPO is relevant and to select interesting compounds or extracts able to modulate the MPO activity. [less ▲]

Pré-dimensionnement par simulations dynamiques d’un réacteur de stockage thermochimique assurant l’autonomie d’un système solaire combiné.

in Congrès Français de Thermique 2011 - Energie Solaire et Thermique - Perpignan - 24-27 Mai 2011 (2011, May 24)

Etude du stockage de l’énergie solaire thermique sous forme thermochimique comme moyen d’assurer l’autonomie thermique d’une habitation basse énergie. La surface de capteurs nécessaire et les ... [more ▼]

Etude du stockage de l’énergie solaire thermique sous forme thermochimique comme moyen d’assurer l’autonomie thermique d’une habitation basse énergie. La surface de capteurs nécessaire et les caractéristiques du stockage sont étudiées par simulation dynamique (TRNSYS), de manière générale et pour des couples adsorbant/adsorbat particuliers (CaCl2/H2O et Charbon actif/Méthanol). Un système solaire combiné avec 14,4 m² de capteurs plans et un stockage thermochimique de 12,35 m³ de CaCl2 permet d’assurer l’autonomie thermique d’une habitation « basse énergie » située en Belgique et une grande part de la production d’eau chaude sanitaire (ECS). [less ▲]

Le goût et le toucher de la ville. La perception sensible de la ville par les sensorialités basses (XVIIIe siècle)

in Beck, Robert (Ed.) Les cinq sens de la ville (2011, May 20)

A pragmatic Approach to quantify the effects of KENLW

in 6th European Symposium on Non-Lethal Weapons 2011 proceedings (2011, May 16)

Measurement of the force occuring at the impact of a non-lethal projectile with the Flexiforce sensor

in 6th European Symposium on Non-Lethal Weapons 2011 proceedings (2011, May 16)

Force measurements are important to experimentally assess the effects of a non- lethal projectile on a human body. In addition they are also necessary to evaluate the bio-fidelity of a system regarding ... [more ▼]

Force measurements are important to experimentally assess the effects of a non- lethal projectile on a human body. In addition they are also necessary to evaluate the bio-fidelity of a system regarding PMHS (post mortem human subject) data. So far, as we can see in the literature, these measurements are usually achieved with an accelerometer placed inside the projectile. By assuming this projectile is perfectly rigid, the impact force can be calculated [1, 2]. However, the limitations are obvious: on the one hand the embedded accelerometer will change the projectile properties. On the other hand the force cannot directly be deduced for the deformable projectiles usually used nowadays. Therefore, a new system to measure impact force has to be developed. In this study, we propose to use the Flexiforce sensor, which is a cheap and very thin force sensor compatible with the expected measurement range [3]. The final objective is to realise an efficient force measurement on any kinetic energy non-lethal weapon (KENLW) projectile, using this particular sensor. We can find in the literature some static calibration [3,4]. As our application is highly dynamical, we started this study with the design and application of a dynamic calibration process. Then results from rigid projectiles (comparing to a classic KENLW projectile) impacting rigid targets (comparing to human body or a biofidelic surrogate) are collected and Flexiforce and accelerometer signals are compared (“rigid-rigid impacts). Finally, force measurements of projectiles impacting deformable surfaces (comparing to the projectile ) with the Flexiforce sensor are achieved (“rigid-soft impacts”). [less ▲]

A Generic Service Interface for Cloud Networks

in Leymann, Frank; Ivanov, Ivan; van Sinderen, Marten (Eds.) CLOSER (2011, May 09)

Two major challenges for enabling the vision of cloud computing regard (a) the generic and multi-purpose access to (virtualised) resources, and (b) the flexible, dynamic, and on-demand composition of ... [more ▼]

Two major challenges for enabling the vision of cloud computing regard (a) the generic and multi-purpose access to (virtualised) resources, and (b) the flexible, dynamic, and on-demand composition of services from virtual resources; from the service level, all the way ``down'' to the lamda level. Both aspects require a respective flexibility and expressibility from the interfaces in-place, which is missing from the current static socket (and other) interfaces below the application level. In this position paper, we propose, explain and exemplify an alternative generic and universal resource interface (GRI) that borrows from object oriented design to enable properties such as polymorphic access, generic service composition, introspection and dynamic reconfigurability, of in-network resources, opening in this way the path for flexible creation of service clouds. [less ▲]

Gas sensor array applied to the monitoring of biogas process

in Gouma, Perena (Ed.) Proceedings of the International Symposium on Olfaction and Electronic Nose 2011 (2011, May)

There is a lack of simple online monitoring system to control the performances of biogas reactors. The electronic nose technology appears to be an adapted device to deliver fast information about process ... [more ▼]

There is a lack of simple online monitoring system to control the performances of biogas reactors. The electronic nose technology appears to be an adapted device to deliver fast information about process disturbances in anaerobic reactors as it is adequate for online monitoring. In this study, twelve anaerobic mini-reactors were supervised with a home-made e-nose to observe process reaction in relation to organic overloads events. Usually, to avoid overload situations, on farms reactors are not fed at maximum load capacity, resulting in non optimized biogas production. The objective of the experiment was to determine if the gas sensors array feature can be related to the process state and if an indirect state variable, giving early warning of process faults, can be derived from the e-nose response. The results demonstrated that focusing on gas phase of anaerobic reactors with a simple device composed of an array of non-specific gas sensors helped in the warning of disorders of the anaerobic digestion process. Mahalanobis distance from a cautious feeding group (group of observations indicating a good process) can be used as an indirect variable to evaluate the intensity of the state disorder. Euclidean distance has been also calculated but it was less informative than the Mahalanobis distance. [less ▲]

IRF3 is essential for house dust mite-induced airway allergy in mice

in Proceedings GIGA-Day 2011 (2011, May)

Uprating Transmission Lines through the use of an innovative real-time monitoring system

in Proceedings of the 12th International Conference & Exposition on Transmission & Distribution, Operation & Live-Line Maintenance of the World's Power Delivery Systems (2011, May)

This paper describes a brand new method of real-time monitoring of overhead transmission lines. The method makes use of what is called the “Ampacimon” system. The system uses an Ampacimon module, which is ... [more ▼]

This paper describes a brand new method of real-time monitoring of overhead transmission lines. The method makes use of what is called the “Ampacimon” system. The system uses an Ampacimon module, which is a real time monitoring device that deduces the sag by vibration analysis without the need for any line data or environmental data. The Ampacimon system has been proven to be accurate within a sag error margin of ±2%. [less ▲]

Le consentement du mineur

in Responsabilités autour et alentours du mineur (2011, May)

Galileo Single Frequency Ionospheric Correction: Performances in Terms of Position

in Goodman, John M. (Ed.) 2011 Ionospheric Effects Symposium Proceedings (2011, May)

The ionospheric effect remains one of the main factors limiting GNSS accuracy. For GPS single frequency users, this contribution to the error budget is estimated thanks to the well-known Klobuchar ... [more ▼]

The ionospheric effect remains one of the main factors limiting GNSS accuracy. For GPS single frequency users, this contribution to the error budget is estimated thanks to the well-known Klobuchar algorithm. For Galileo, it will be mitigated by a global algorithm based on the NeQuick model. This algorithm relies on an optimisation procedure called ingestion. In this framework, an "effective ionisation level" Az plays the role of the solar activity information provided to the model in order to fit a specific dataset. For Galileo single frequency operation, daily Az values will be computed from slant Total Electron Content (sTEC) measurements performed within the ground segment and three coefficients will be broadcast to the users within the navigation message allowing them to run the model. The performance specifications of these algorithms are respectively expressed in terms of delay and TEC but the users might find more interest in their impact on positioning. Hence we propose to investigate their performances in terms of positioning accuracy. To this extent we compare positions of permanent stations calculated with and without the ionospheric correction to the actual ones which are known at the sub-centimetre level. Our simulation uses sTEC generated from Global Ionospheric Maps to provide the effective ionization level coefficients and GPS single frequency code measurements to compute positions. We present results for Brussels station in Belgium (mid-latitudes) and for 2002 (high solar activity level). It gives an interesting insight in the situation we could observe when Galileo reaches its Initial Operation Capability, during the next solar maximum. This study constitutes a first step in the development of a real-time service in the framework of the SWANS project of the University of Liège and the Royal Meteorological Institute of Belgium. As two Galileo receivers have been bought in this context, this service will be available for the In-Orbit Validation phase of Galileo. [less ▲]

Argument du contrôle et scénarisation: une approche narrative du pouvoir.

in Wintgens, Sophie; Piet, Grégory (Eds.) La Puissance: débat autour des jeux et des enjeux du pouvoir (2011, April 27)

Effects of the electrode positions on the dynamical behaviour of electrostatically actuated MEMS resonators

(2011, April 18)

The influence of the lower electrode positions on the dynamic response of polysilicon MEMS resonators is studied and presented in this paper. The change in the frequency response of investigated MEMS ... [more ▼]

The influence of the lower electrode positions on the dynamic response of polysilicon MEMS resonators is studied and presented in this paper. The change in the frequency response of investigated MEMS resonators as function of the lower electrode positions is measured using a vibrometer analyzer. The decrease in the amplitude and velocity of oscillations if the lower electrode is moved from the beam free-end toward to the beam anchor is experimental monitored. The measurements are performed in ambient conditions in order to characterize the forced-response Q-factor of samples. A decrease of the Q- factor if the lower electrode is moved toward to the beam anchor is experimental determined. Different responses of MEMS resonators may be obtained if the position of the lower electrode is modified. Indeed the resonator stiffness, velocity and amplitude of oscillations are changed. [less ▲]

Methodology for the characterization of the microstructure of nanocomposite polymeric foams using X-ray microtomography

in Micro-CT User Meeting Abstract Book (2011, April 13)

Polymeric foams used in electromagnetic shielding applications are characterized using X-ray microtomography. These foams contain a conductive nanometric reinforcement, carbon nanotubes, but the scale of ... [more ▼]

Polymeric foams used in electromagnetic shielding applications are characterized using X-ray microtomography. These foams contain a conductive nanometric reinforcement, carbon nanotubes, but the scale of characterization described here is that of the microscopic cells. Although nanotube dispersion is important for the final properties of the material, the structure and distribution of the porosity also play a role in terms of dielectric constant and conductivity. Unfortunately, cell wall thinness and limited resolution of laboratory microtomographs makes poper cell identification difficult. Therefore we present a new statistical method based on the 3D autocorrelation function, that allows to some extent to measure mean cell size and structure anisotropy. [less ▲]

Platelet-rich plasma and tendons healing: rat model

in Biomedica Life Science Summit (2011, April 07)

The COSPIX mission: focusing on the energetic and obscured Universe

in Rieger, F.; van Eldik, C. (Eds.) 25th Texas Symposium on Relativistic Astrophysics (2011, April 01)

Tracing the formation and evolution of all supermassive black holes, including the obscured ones, understanding how black holes influence their surroundings and how matter behaves under extreme conditions ... [more ▼]

Tracing the formation and evolution of all supermassive black holes, including the obscured ones, understanding how black holes influence their surroundings and how matter behaves under extreme conditions, are recognized as key science objectives to be addressed by the next generation of instruments. These are the main goals of the COSPIX proposal, made to ESA in December 2010 in the context of its call for selection of the M3 mission. In addition, COSPIX, will also provide key measurements on the non thermal Universe, particularly in relation to the question of the acceleration of particles, as well as on many other fundamental questions as for example the energetic particle content of clusters of galaxies. COSPIX is proposed as an observatory operating from 0.3 to more than 100 keV. The payload features a single long focal length focusing telescope offering an effective area close to ten times larger than any scheduled focusing mission at 30 keV, an angular resolution better than 20 arcseconds in hard X-rays, and polarimetric capabilities within the same focal plane instrumentation. In this paper, we describe the science objectives of the mission, its baseline design, and its performances, as proposed to ESA. [less ▲]

Interdisciplinary Research in the Field of Conservation: the Role of Analytical Philosophy and Ontology of Art in the Authenticity Assessment

in D'Amato, Claudio (Ed.) Ist International Congress Rete Vitruvio - Architectural design between teaching and research - Proceedings (2011, April)

Quality meshing algorithms for accurate and efficient cardiovascular simulations

in Nithiarasu, P.; Lohner, R. (Eds.) Procedings of the 2nd International Conference on Mathematical and Computational Biomedical Engineering (CMBE2011) (2011, April)

Des guerres contre l’anarchie : constructions idéologiques à la cour de France au temps des premières Guerres d’Italie (1494–1525).

in CTHS (Ed.) Faire la guerre. Faire la paix. Actes du 136e Congrès des Sociétés historiques et scientifiques (2–7 mai 2011) (2011, April)

La gestion du patrimoine de l'incapable délocalisé - quelques leçons à l'attention de la pratique

in Leleu, Yves-Henri (Ed.) Chroniques de droit à l'intention du notariat (2011, April)

Le texte donne un aperçu pratique des questions de droit international privé liées à la gestion du patrimoine de l'incapable (tant mineur que majeur). Pour ce faire, cinq cas pratiques sont étudiées, qui ... [more ▼]

Le texte donne un aperçu pratique des questions de droit international privé liées à la gestion du patrimoine de l'incapable (tant mineur que majeur). Pour ce faire, cinq cas pratiques sont étudiées, qui permettent d'analyser les principales questions liées au patrimoine de l'incapable. [less ▲]

Les déterminants du design des systèmes de contrôle de gestion dans les collectivités locales de l’Afrique au Sud du Sahara: une analyse empirique contingente des collectivités locales béninoises

in AFC (Ed.) Actes du 32ème Congrès de l'Association Francophone de Comptabilité (2011, April)

The current paper aims to test the factors that influence the design of the systems of management control in the local collectivities in Sub-Sahara Africa empirically. The factorial analysis in multiple ... [more ▼]

The current paper aims to test the factors that influence the design of the systems of management control in the local collectivities in Sub-Sahara Africa empirically. The factorial analysis in multiple correspondence permitted to conclude that outside of the usual organizational factors as the organizational culture, the organizational strategy, the organizational structure and the politics of management of the human resources, the legal and institutional pressures, the pressures of the financial dependence, the ethnic pressures and the religious pressures are the major key that determine the design of the Management control system in local Sub-Saharian collectivities. [less ▲]

Evaluation des pratiques éducatives des enseignants en géographie : constats et propositions

in Miralles Martinez, P.; Molina Puche, S.; Santisteban Fernandez, A. (Eds.) La evaluacion en el proceso de ensenanza y aprendizaje de las ciencias sociales (2011, April)

L’évaluation des pratiques éducatives est un champ nouveau des recherches tant en didactique générale qu’en didactique des disciplines. Les travaux relatifs à la géographie étant à notre connaissance ... [more ▼]

L’évaluation des pratiques éducatives est un champ nouveau des recherches tant en didactique générale qu’en didactique des disciplines. Les travaux relatifs à la géographie étant à notre connaissance encore rares, le propos de cette communication est de dresser un premier bilan en nous appuyant principalement sur des recherches menées par des chercheurs en sciences de l’éducation et sur notre expérience personnelle. Après avoir tenté de définir l'objet de ces pratiques et leur intérêt comme objet d'étude, l'article discute des pratiques en géographie et propose quelques pistes de recherche-action. [less ▲]

Characterizing the operability limits of the HyShot II scramjet through RANS simulations

in 17th AIAA International Space Planes and Hypersonic Systems and Technologies Conference 2011, Vol. 2; No AIAA 2011-2282 (2011, April)

Experimental and flight data for hypersonic air-breathing vehicles are both difficult and extremely expensive to obtain, motivating the use of computational tools to enhance our understanding of the ... [more ▼]

Experimental and flight data for hypersonic air-breathing vehicles are both difficult and extremely expensive to obtain, motivating the use of computational tools to enhance our understanding of the complex physics involved. One of the major difficulties in simulating this regime is the interaction between combustion and turbulence, both of which are intrinsically complex processes. This work represents a first attempt at addressing assumptions introduced by physical models representing the turbulent reacting flow on the resulting predictions of the scramjet performance. A combustion model for high-speed flows is introduced and tested for the HyShot II vehicle. A reduced order chemistry model is then derived to investigate the effect of certain chemistry modeling assumptions within the combustion model. These models are used to investigate the unstart of the engine due to thermal choking by increasing the fuel flow rate. It is shown that an abrupt change occurs where a normal shock forms and moves upstream accompanied by a large region of subsonic flow. Additionally scalar metrics are described which are used as early indicators of unstart, to formulate safe operating limits for the scramjet engine. [less ▲]

Calculs d'endurance par similitude

in Zenasni, Mohamed (Ed.) 10 ème Edition du Congrès International de Mécanique (2011, April)

The essential difficulty of the design against fatigue lies in the fact that the fatigue strength depends not only on the material, but also on the scale. It is true that models do exsist from long, but ... [more ▼]

The essential difficulty of the design against fatigue lies in the fact that the fatigue strength depends not only on the material, but also on the scale. It is true that models do exsist from long, but they are limited to those geometries with known stress concentration factor and known gradient. Now, there exist a lot of problems for which these two parameters are not known, the most obvious being the press-fitted assembly. Such cases will be called unpredictable notches. The aim of the present communication is to present a similarity method leading to a liable prediction of the behaviour of such notches, from partial experimental data. Comaparing the results of the present method to publishes results, a fair agreement is found. [less ▲]

An Efficient Flamelet-based Combustion Model for Supersonic Flows

in 17th AIAA International Space Planes and Hypersonic Systems and Technologies Conference 2011, Vol. 2; No AIAA 2011-2267 (2011, April)

A combustion model based on a Flamelet/Progress Variable approach for high-speed flows is introduced. In the proposed formulation, the temperature is computed from the transported total energy and ... [more ▼]

A combustion model based on a Flamelet/Progress Variable approach for high-speed flows is introduced. In the proposed formulation, the temperature is computed from the transported total energy and tabulated species mass fractions. The combustion is thus modeled by 3 additional scalar equations and a chemistry table that is computed in a pre-processing step. This approach is very efficient and allows the use of complex chemical mechanisms. An approximation is also introduced to eliminate costly iteration steps during the temperature calculation. To better account for compressibility e ects, the source term for the progress variable is rescaled with the pressure. The model is tested in both RANS and LES computations of a hydrogen jet in a supersonic transverse flow. Comparison with experimental measurements shows good agreement, particularly in the LES case. It is also found that the disagreement between RANS results and experimental data is mostly due to the mixing model de ciencies used in RANS. [less ▲]

Generating smooth surface meshes from labelled medical datasets

in Nithiarasu, Perumal; Löhner, Rainald; van Loon, Raoul (Eds.) et al CMBE11: 2nd International Conference on Computational & Mathematical Biomedical Engineering, 30 March - 1 April, 2011, Washington D.C. U.S.A. (2011, March 30)

In this article, an innovative procedure to create high quality triangular meshes from medical scans is proposed. The approach is based on an enhanced Marching Tetrahedra algorithm that extracts a ... [more ▼]

In this article, an innovative procedure to create high quality triangular meshes from medical scans is proposed. The approach is based on an enhanced Marching Tetrahedra algorithm that extracts a consistent multiple region surface mesh from a labelled volume data set; coupled with a surface reconstruction method to avoid typical staircase artifacts. Mesh smoothing and decimation algorithms are also revised to conform to the multiple material nature of the system as well as to adhere to the underlying volume data. The proposed method is well suited for subsequent volume mesh generation and finite element simulations. [less ▲]

Les soins aux animaux dans la médecine monastique et domestique

in Colloque : Chevaux, chiens, faucons : l'art vétérinaire antique et médiéval à travers les sources écrites, archéologiques et iconographiques (2011, March 24)

ManageMilk - Création d'outils de management innovatifs et pratiques en vue d'améliorer la durabilité de la production laitière et de la qualité des produits laitiers: présentation du projet.

in 16ième Carrefour des Prodcutions animales: La filière laitière bovine européenne est-elle durable? (2011, March 02)

Estimation de la quantité journalière grasse du lait à partir d'une seule traite (matin ou soir) des composés fins de la matière grasse du lait

in 16ième Carrefour des Productions animales: la filière laitière bovine européenne est-elle durable? (2011, March 02)

OptiMIR- Développement et mise en place d'outils innovants de gestion des troupeaux et de conseil personnalisé pour une meilleure durabilité du secteur laitier

in 16ème Carrefour des Productions animales: La filière laitière bovine européenne est-elle durable? (2011, March)

Quality surface meshing using discrete parametrizations

in Proceedings of the 16th International Conference on Finite Elements in Flow Problems (FEF 2011) (2011, March)

Nueva mutacion de AIP en adenomas hipofisarios familiares (FIPA)

in Abstract book - XIV congreso de la Sociedad de Endocrinologia, diabetes y nutricion de Euskadi (2011, March)

Variabilité et amélioration des aptitudes à la transformation fermière du lait au travers du projet ProFARMilk

in 16ième Carrefour des Productions animales: La filière laitière bovine européenne est-elle durable? (2011, March)

Conservation et valorisation de la Bleue Mixte au travers du projet franco-belge BlueSel

in 16ième Carrefour des Productions animales: La filière laitière bovine européenne est-elle durable? (2011, March)

GPR Limits for Thin Layers in Concrete Detection: Numerical and Experimental Evaluation

in Progress In Electromagnetics Research Symposium Proceedings, Marrakesh, Morocco, March 20-23, 2011 (2011, March)

The Ground Penetrating Radar (GPR) is a nondestructive technique increasingly used in civil structures inspection. In those structures, thin layers, presenting a relatively small thickness compared to ... [more ▼]

The Ground Penetrating Radar (GPR) is a nondestructive technique increasingly used in civil structures inspection. In those structures, thin layers, presenting a relatively small thickness compared to their area, are common and induce a complex multiple reflection scheme of the GPR waves on the two interfaces limiting the layer. The theoretical relationships predicting the reflected amplitude are based on multiple simplifying assumptions that are not matched by most commercial GPR impulse machines. In the first part of this study, we confronted the theoretical curves with numerical finite difference simulations performed with GprMax2D, with both a continuous sine wave and a realistic pulse derived from measurements. In the second part, we performed experiments on two concrete slabs, separated with an air space of variable thickness. The measured amplitude appeared to be different from the predictions, probably due to surface noise. [less ▲]

4. La fumure azotée

in Livre Blanc: Céréales - Gembloux (2011, February 23)