References of "2012"
     in
Bookmark and Share    
Full Text
See detailEnergy performance assessment of an existing double-skin façade: measurements and simulation
Carton, Julien UL; Scholzen, Frank UL; Thomas, Sébastien et al

in Energy Forum - Solar Building Skins, 06 - 07 December 2012, Italy (2012, December)

An existing office building with an active double skin façade in Luxembourg has been analyzed. In the first step in-situ measurements have been performed. For this purpose outside, inside and cavity ... [more ▼]

An existing office building with an active double skin façade in Luxembourg has been analyzed. In the first step in-situ measurements have been performed. For this purpose outside, inside and cavity conditions have been measured for representative summer and winter conditions. In a second step, a thermal simulation using TRNSYS was performed. The simulation model has been compared to the time limited series of measurements and thus has been validated for some of the annual meteorological conditions. Then the model has been extrapolated to a whole year in order to assess the energy performance of the given façade. Further a parametric study of alternative façades has been carried out based on the validated simulation model to assess their own performances. For the given case study building, the double skin concept energetically performs well compared to other concepts with non outside (non weather exposed) solar protection, but worse than an external solar protection. The thermal comfort level in the rooms has also been determined by simulation - the calculated room averaged comfort level is quite optimal, but further investigations regarding the local comfort close to the glazed façades still have to be achieved. [less ▲]

Detailed reference viewed: 148 (16 UL)
Full Text
Peer Reviewed
See detailDynamical structure function identifiability conditions enabling signal structure reconstruction
Adebayo, J.; Southwick, T.; Chetty, V. et al

in The proceedings of the 51st IEEE Conference on Decision and Control (CDC) (2012, December)

Networks of controlled dynamical systems exhibit a variety of interconnection patterns that could be interpreted as the structure of the system. One such interpretation of system structure is a system's ... [more ▼]

Networks of controlled dynamical systems exhibit a variety of interconnection patterns that could be interpreted as the structure of the system. One such interpretation of system structure is a system's signal structure, characterized as the open-loop causal dependencies among manifest variables and represented by its dynamical structure function. Although this notion of structure is among the weakest available, previous work has shown that if no a priori structural information is known about the system, not even the Boolean structure of the dynamical structure function is identifiable. Consequently, one method previously suggested for obtaining the necessary a priori structural information is to leverage knowledge about target specificity of the controlled inputs. This work extends these results to demonstrate precisely the a priori structural information that is both necessary and sufficient to reconstruct the network from input-output data. This extension is important because it significantly broadens the applicability of the identifiability conditions, enabling the design of network reconstruction experiments that were previously impossible due to practical constraints on the types of actuation mechanisms available to the engineer or scientist. The work is motivated by the proteomics problem of reconstructing the Per-Arnt-Sim Kinase pathway used in the metabolism of sugars. [less ▲]

Detailed reference viewed: 57 (0 UL)
Full Text
See detailModelling Thermochemical Processes in Granular Media
Hoffmann, Florian UL

Presentation (2012, October 26)

Detailed reference viewed: 57 (1 UL)
Peer Reviewed
See detailIn-silico Robust Reconstruction of the Per-Arnt-Sim Kinase Pathway using Dynamical Structure Functions
Chetty, V.; Adebayo, J.; Mathis, A. et al

Scientific Conference (2012, October)

Detailed reference viewed: 46 (1 UL)
Full Text
See detailtrend Analysis and interpretation of Luxembourg’s consumption Footprint NFA 2010 edition, data years 2000 – 2007
Hild, Paula UL; Takagi, Aya; Schmitt, Bianca

Report (2012)

The Ecological Footprint methodology by Global Footprint Network measures human consumption of products and services from different ecosystems in terms of the amount of bioproductive land and sea area ... [more ▼]

The Ecological Footprint methodology by Global Footprint Network measures human consumption of products and services from different ecosystems in terms of the amount of bioproductive land and sea area needed to supply these products and services. In other words, the Ecological Footprint calculates the land area needed to produce food, provide resources, produce energy, and absorb the CO2 emissions generated by the supply chains within one year at country level. For the calculations of Luxembourg’s Ecological Footprint, international statistical databases are used to identify the quantities of produced, imported and exported goods and services. Then, Global Footprint Network applies different factors to the quantities to assess the area needed to supply these products and services. Finally, the Consumption Footprint of a nation is divided by the number of inhabitants and compared to other countries at a per capita level (global hectares per capita). This means that the Ecological Footprint can be used as an indicator for the sustainability of a national consumption by assessing human land uses. In the following paragraph, Luxembourg’s Ecological Footprint is discussed in the framework of the environmental indicators of Luxembourg’s competitiveness scoreboard (see Table 9) [MECE, 2010]. Luxembourg’s ranking is rather low for all of the scoreboard indicators: number of ISO 9001 certifications per billion of inhabitants (21 out of 27); number of ISO 14001 certifications per billion of inhabitants (15 out of 27); total greenhouse gas emissions (15 out of 27); renewable energy ration (23 out of 27); quantity of municipal waste per capita per year (24 out of 27); energetic intensity (8 out of 27); transport by car (17 out of 27); Ecological Footprint in gha per capita per year (27 out of 27). Based on the environmental competiveness scoreboard indicators, it can be concluded that in general, Luxembourg’s environmental performance is low compared to the other countries of the European Union. With respect to Luxembourg’s Ecological Footprint, it can be said that Luxembourg’s consumption is not sustainable. The number of planets that would be needed if the world's population lived like the population of Luxembourg in 2007 is about six. However, per year, the biocapacity (bioproductive land) of the planet can only regenerate once. [less ▲]

Detailed reference viewed: 72 (3 UL)
See detailNumerical Investigation into the Primary Breakup of Liquid Jets and Sheets
Kannan, Kumar UL

Doctoral thesis (2012)

Detailed reference viewed: 119 (3 UL)
Full Text
Peer Reviewed
See detailSecure and Reliable Clustering in Wireless Sensor Networks: A Critical Survey
Schaffer, Peter UL; Farkas, Károly; Horváth, Ádám et al

in Computer Networks (2012), 56(11), 27262741

In the past few years, research interest has been increased towards wireless sensor networks (WSNs) and their application in both the military and civil domains. To support scalability in WSNs and ... [more ▼]

In the past few years, research interest has been increased towards wireless sensor networks (WSNs) and their application in both the military and civil domains. To support scalability in WSNs and increase network lifetime, nodes are often grouped into disjoint clusters. However, secure and reliable clustering, which is critical in WSNs deployed in hostile environments, has gained modest attention so far or has been limited only to fault tolerance. In this paper, we review the state-of-the-art of clustering protocols in WSNs with special emphasis on security and reliability issues. First, we define a taxonomy of security and reliability for cluster head election and clustering in WSNs. Then, we describe and analyze the most relevant secure and reliable clustering protocols. Finally, we propose countermeasures against typical attacks and show how they improve the discussed protocols. [less ▲]

Detailed reference viewed: 53 (0 UL)
See detailGestural Interfaces for Elderly Users - Help or Hindrance?
Stossel, Christian UL

Doctoral thesis (2012)

Detailed reference viewed: 76 (1 UL)
Full Text
See detailLow-energy Secondary Ion Mass Spectrometry: Investigation of buried interfaces in multi-layer organic thin films
Ngo, Khanh Quyen UL

Doctoral thesis (2012)

Recently, the application of conjugated organic compounds increases significantly in optoelectronic devices. The main performances of these devices such as charge and energy transport, operational ... [more ▼]

Recently, the application of conjugated organic compounds increases significantly in optoelectronic devices. The main performances of these devices such as charge and energy transport, operational lifetime and energy conversion efficiency depend strongly on the doping and the interface structure. Therefore, in this project we develop dynamic SIMS analysis conditions using low energy primary ion beam to analyse multi-layered samples used in organic optoelectronic devices. The objective of this thesis is to study the different artefacts and mechanisms, which may arise in the low-energy depth profiling of organic materials and to optimize the SIMS conditions for interface resolution. For the objectives, in chapter I and II, a general introduction about the organic molecules, the fabrication techniques as well as fundamental aspects of the SIMS technique and the analysis conditions are presented. In chapter III, a study of the fragmentation of different organic films during sub-keV bombardment is performed. The typical secondary ions of different organic molecule are identified and chosen for depth profiling. Chapter IV is a study about air-contact induced topography change on Cs+ sputtered surface. This is useful to avoid artefacts when characterizing the Cs+ sputtered surfaces by AFM or by other techniques. The ability of low-energy SIMS to characterize the metal/organics interfaces is investigated in chapter V and VI. Chapter V is about the SIMS depth resolution and sputter-induced surface roughness studied on a series of metal – organic layered samples. In chapter VI, the diffusion of metal into organic layer seen in SIMS depth profiles is characterized. [less ▲]

Detailed reference viewed: 61 (4 UL)
Full Text
Peer Reviewed
See detailModification of the Shear-Slip Mesh Update Method with Respect to Space-Time Finite Element Discretisation of Fluid Flows
Schippke, Henning; Zilian, Andreas UL

Scientific Conference (2012, April 27)

Space-time discretisations of physical problems involving moving and deforming bodies, boundaries and interfaces have been shown to offer advantageous properties while being methodologically uniform and ... [more ▼]

Space-time discretisations of physical problems involving moving and deforming bodies, boundaries and interfaces have been shown to offer advantageous properties while being methodologically uniform and flexible. Well-known phenomena which are ideally suited to be analysed by space-time methods, are fluid-structure interaction problems in general as well as fluid flows with subdomain phase boundaries or immersed moving objects. In this contribution a short overview of existing mesh- moving techniques is given within the framework of finite element discretisations of the incompressible Navier-Stokes equations in space and time. The investigation is based on a SUPG/PSPG velocity-pressure formulation on the deforming space-time domain. A modification of the shear-slip mesh update method in the framework of space-time finite element discretisation is presented leading to a continuous space-time mesh in the shear-slip layer. The modified mesh moving technique is applied to engineering problems with rotating space-time fluid meshes. Its conservation properties and its quality regarding the approximated solutions on moving and deforming meshes are investigated. [less ▲]

Detailed reference viewed: 95 (1 UL)
Full Text
Peer Reviewed
See detailGraphviz e TikZ
Fiandrino, Claudio UL

in Ars TeXnica (2012), 13

Graphviz is a very powerful tool to draw graphs. This article tries to explain how to export such graphs as a TikZ picture in a very simple way.

Detailed reference viewed: 94 (8 UL)
Full Text
See detailSensitivity analysis and shape optimisation with the isogeometric boundary element methods
Lian, Haojie; Simpson, Robert; Bordas, Stéphane UL

Scientific Conference (2012, March 27)

Detailed reference viewed: 237 (5 UL)
Full Text
Peer Reviewed
See detailALGEBRAIC COARSE-GRAINING METHODS IN FRACTURE MECHANICS: TACKLING LOCAL LACK OF CORRELATION USING DOMAIN DECOMPOSITION
Goury, Olivier; Kerfriden, Pierre; Rabczuk, Timon et al

Scientific Conference (2012, March)

In this paper, we propose to couple model order reduction techniques with domain decomposition meth- ods for the solution to parametric problems of fracture. The nonlinear nature of the problems requires ... [more ▼]

In this paper, we propose to couple model order reduction techniques with domain decomposition meth- ods for the solution to parametric problems of fracture. The nonlinear nature of the problems requires the use of a system approximation method to speed-up the assembly of the non-linear opreators. We show that the method efficiently computes a solution faster than a full order model for a given accuracy. The speed-up increases with the problem size. [less ▲]

Detailed reference viewed: 209 (1 UL)
Full Text
See detailAssessment of implicit and explicit algorithms in numerical simulation of granular matter
Samiei, Kasra UL

Doctoral thesis (2012)

The objectives of this dissertation are to investigate and demonstrate the potentials of implicit integration methods in predicting the dynamics of granular media and to describe the granular dynamics on ... [more ▼]

The objectives of this dissertation are to investigate and demonstrate the potentials of implicit integration methods in predicting the dynamics of granular media and to describe the granular dynamics on forward and backward acting grates by discrete element method. Traditionally, explicit integration methods are employed within the context of Discrete Element Method. Generally, explicit equations are simpler to solve than the implicit ones but they require a small time step to be utilized. In this study, an implicit Numerov integration scheme is employed to integrate the equations of motion. The implicit method is verified in different test cases starting from simple cases to more complicated cases including hundreds of particles. Comparing the results with the results of the explicit method, it is shown that the implicit method exhibits a distinguished advantage only at very large time steps. Taking into account the overhead of solving non-linear equations at each time step, it is concluded that implicit methods are computationally too expensive for their limited gains. Addressing the second objective of this study, the residence time distribution of granular particles on forward and backward acting grates are numerically predicted. Very good agreement between the predictions and the available experimental results is achieved. It can be concluded that the Discrete Element Method is highly capable of predicting the dynamics of solid fuel particles on grate systems. Future work shall include coupling of the method with computational fluid dynamics in order to account for thermal conversion of the fuel particles. [less ▲]

Detailed reference viewed: 131 (3 UL)