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See detailDesign of a morphological moving object signature and application to human identification
Barnich, Olivier ULg; Van Droogenbroeck, Marc ULg

in International Conference on Acoustics, Speech, and Signal Processing (ICASSP 2009) (2009, April)

Many computer vision systems try to infer semantic information about a video scene content by looking at the time series of the silhouettes of the moving objects. This paper proposes a new inter-frame ... [more ▼]

Many computer vision systems try to infer semantic information about a video scene content by looking at the time series of the silhouettes of the moving objects. This paper proposes a new inter-frame feature set (signature) based on piecewise surfacic descriptions of binary silhouettes. It captures the dynamics of moving objects and compacts it into a robust set of features suitable for classification. To assess its ability to represent motion information, we use it to build a complete gait recognition algorithm that we test on a database of 21 different subjects. To highlight the efficiency of our signature, we use frontal views instead of side views of persons, which is less discussed in literature and is considered to be harder as the movement of legs is not visible. In that context, the high recognition rates obtained (over 95% of correct identifications) proves that our signature is appropriate to describe moving objects. [less ▲]

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See detailDesign Of A New Class Of Amphipathic Helical Peptides For The Plasma Apolipoproteins That Promote Cellular Cholesterol Efflux But Do Not Activate Lcat
Labeur, C.; Lins, Laurence ULg; Vanloo, B. et al

in Arteriosclerosis, Thrombosis, and Vascular Biology (1997), 17(3), 580-8

Amphipathic helical peptides represent the lipid-binding units of the soluble plasma apolipoproteins. Several synthetic peptide analogues have been designed to mimic such structures and have been used to ... [more ▼]

Amphipathic helical peptides represent the lipid-binding units of the soluble plasma apolipoproteins. Several synthetic peptide analogues have been designed to mimic such structures and have been used to unravel some of the mechanisms involved in the physiological function of the apolipoproteins, including lipid binding, LCAT activation, and enhancement of cholesterol efflux from lipid-laden cells. A series of novel synthetic peptides, named ID peptides, was modeled on the basis of the structural properties common to the amphipathic helices of apolipoprotein (apo) A-I. In these new peptides, however, the segregation between hydrophobic and hydrophilic faces of the helices is more pronounced than in apoA-I, so that the surface of the hydrophobic and hydrophilic faces of the amphipathic helices is equal. Moreover, there are fewer negatively charged residues in the center of the hydrophilic face of the helical peptides. Most charged amino acids are located along the edge of the helix and are susceptible to forming salt bridges with residues of an antiparallel helix, such as around a discoidal phospholipid/peptide complex. The physicochemical characteristics of these peptides and their complexes with phospholipids were compared with those of the 18A peptide and its lipid/peptide complex. All ID peptides bind dimyristoylphosphatidylcholine vesicles more rapidly than the 18A peptide to yield discoidal peptide/phospholipid complexes of comparable size. The alpha-helical content of the lipid-free ID peptides is close to that of the 18A peptide and increases slightly on lipid binding. The stability of the ID and 18A peptides and of the phospholipid/peptide complexes against guanidinium hydrochloride denaturation is higher than that of lipid-free and lipid-bound apoA-I. LCAT activation by the 18A/phospholipid/cholesterol complexes equals that of apoA-I/ phospholipid/cholesterol complexes, whereas none of the ID peptides tested is able to activate LCAT to a significant extent. Incubation of the peptide/phospholipid complexes with lipid-laden macrophages induces cellular cholesterol efflux and incorporation of cholesterol into the complexes. The cholesterol efflux capacity of the peptide/phospholipid complexes is comparable among the peptides and higher than that of apoprotein/phospholipid complexes. In conclusion, although the amphipathicity of the new peptides is higher than that of the 18A model peptide, the lack of LCAT activation by the ID peptides suggests that an enhanced segregation of the hydrophobic and hydrophilic residues, equal magnitude of hydrophobic and hydrophilic faces of the helix, and the absence of negatively charged residues in the central part of the hydrophilic face might account for the lack of LCAT activity of these peptides. These parameters do not affect the capacity of the peptide/phospholipid complexes to promote cellular cholesterol efflux. [less ▲]

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See detailDesign of a New Type of Semi-Submersible Structure
Marchal, Jean ULg

in ASME Journal (American Society of Mechanical Engineers) (1987)

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See detailDesign of a novel covert SSVEP-based BCI
Lesenfants, Damien ULg; Partoune, Nicolas; Soddu, Andrea ULg et al

in Proceedings of the 5th International Brain-Computer Interface Conference 2011 (2011, September 22)

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See detailDesign of a reliable processing pipeline for the non-intrusive measurement of feet trajectories with lasers
Pierard, Sébastien ULg; Azrour, Samir ULg; Van Droogenbroeck, Marc ULg

in International Conference on Acoustics, Speech, and Signal Processing (ICASSP) (2014, May)

Reliable measurements of feet trajectories are needed in some applications, such as biomedical applications. This paper describes the data processing pipeline used in GAIMS, which is a non-intrusive ... [more ▼]

Reliable measurements of feet trajectories are needed in some applications, such as biomedical applications. This paper describes the data processing pipeline used in GAIMS, which is a non-intrusive system that measures feet trajectories based on multiple range laser scanners. Our processing pipeline relies on a new tracking paradigm, and it is based on two innovative algorithms: the first algorithm localizes the feet directly from the observed point cloud without any clustering, and the other algorithm identifies the feet. After reviewing the various types of noise affecting the point cloud, this paper explains the limitations of the classical processing approach and gives an overview of our new pipeline. The effectiveness of the proposed approach is established by discussing the results that have been obtained in several studies based on GAIMS. [less ▲]

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See detailDesign of a Self Compacting Repair Mortar to be applied under concrete slabs and floors
Flamant, St; Courard, Luc ULg

in Marchand, J.; Bissonnette, B.; Gagné, R. (Eds.) et al Advances in Concrete through Science and Engineering (2006, September)

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See detailDesign of a single-species biofilm reactor based on metal structured packing for the production of high added value biomolecules
Zune, Quentin ULg

Doctoral thesis (2015)

Thesis summary In the last decade, numerous single-species biofilm reactors of various configurations have been implemented at lab and pilot scale for the production of chemicals and biological products ... [more ▼]

Thesis summary In the last decade, numerous single-species biofilm reactors of various configurations have been implemented at lab and pilot scale for the production of chemicals and biological products. Compared to their counterparts in submerged cultures, these processes benefit from the specific physiology of biofilms, i.e. high robustness of the microbial system, long-term activity, continuous implementation and low ratio size / productivity. However, the risks of biofouling and the lack of analytical tools for the control and the monitoring of biofilms are obstacles for scale-up strategies. Up to now, single-species biofilm reactors have been mainly confined to the production of metabolites ranging from low (bulk chemicals) to medium (fine chemicals) added values. In this way, there is a need to design efficient single-species biofilm reactors exhibiting good scalability potentials and intended for the production of high added value compounds. In this work, an experimental single-species biofilm reactor has been designed for the production of target molecules derived from metabolic pathways involved in biofilm physiology. On the basis of these criteria, three biological models having good abilities of biofilm formation and secretion performances were selected : - the gram positive bacterium Bacillus subtilis for the production of surfactin, a surface active metabolite involved in biofilm formation. - the filamentous fungus Trichoderma reesei for the production of hydrophobin (HFBII), a surface active protein (7kDa) involved in adhesion process of spores and mycelium on solid surface. - the filamentous fungus Aspergillus oryaze (engineered strain) for the production of a recombinant protein (Gla::GFP) under the control of the glaB promoter specifically activated in solid-state fermentation. The proposed experimental biofilm reactor has the configuration of a trickle-bed bioreactor. The agitation axis of a stirred tank reactor has been removed and replaced by a stainless steel structured packing filling the top of the vessel. The liquid medium, located in the bottom of the vessel is continuously recirculated on the packing element thanks to a peristaltic pump. An ascending air flow is performed above the liquid phase just under the packing element. This thesis reports the screening of the three biological models in the experimental biofilm reactor. The results include the characterization of process performances in terms of biofilm formation and secretion of the target molecule under different operating conditions. An original methodology based on high energy X-ray tomography has been developed to non-invasively visualize and quantify the biofilm colonization inside the packing element. This technique has highlighted that biofilm colonization and liquid phase distribution across the packing are strongly interrelated phenomena. The biofilm of B. subtilis occurring by cell aggregation preferentially developed on solid areas wetted by the liquid. Accordingly, optimal operating conditions improving liquid phase distribution have been defined for biofilm colonization. The fungal biofilm of A. oryzae and T. reesei occuring by cell filamentation equally colonize submerged and aerial surfaces of the packing element. Consequently, another configuration of biofilm reactor comprising a packing element totally immersed in the liquid medium has been investigated. The production yields of surfactin and hydrophobin in the experimental biofilm reactor are respectively 1.25 and 2.64 times greater than those of a submerged culture in a stirred tank reactor. This suggests that surface-active molecules involved in biofilm formation have a real interest for the design of single-species biofilm reactors. Although the Gla::GFP fusion protein is greater produced in the stirred tank culture, its integrity was preserved in the biofilm reactor despite the presence of proteases. This suggests that the quality and the stability of heterologous proteins produced in a fungal biofilm reactor are improved compared with a submerged culture. Finally, the implementation of the biofilm reactor has led to technological progresses including low energy consumption, no foam formation, continuous processing and simplification of downstream process operations. Further experiments should deepen the understanding of structured phenotypic heterogeneity impact on secretion performances in the biofilm reactor. These experiments should consider development of operating conditions allowing for the growth of a thin biofilm homogeneously distributed on the whole surface provided by the packing element in order to optimize nutrients and metabolites mass transfers. The scale-up and the continuous implementation of the process should be also investigated. [less ▲]

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See detailDesign of a small-scale organic Rankine cycle engine used in a solar power plant
Georges, Emeline ULg; Declaye, Sébastien ULg; Dumont, Olivier ULg et al

in International Journal of Low Carbon Technologies (2013)

Under the economic and political pressure due to the depletion of fossil fuels and global warming concerns, it is necessary to develop more sustainable techniques to provide electrical power. In this ... [more ▼]

Under the economic and political pressure due to the depletion of fossil fuels and global warming concerns, it is necessary to develop more sustainable techniques to provide electrical power. In this context, the present study aims at designing, building and testing a small-scale organic Rankine cycle (ORC) solar power plant ( 3 kWe) in order to define and optimize control strategies that could be applied to larger systems. This paper presents a first step of the design of the solar power plant and focuses more specifically on the ORC engine. This design is defined on the basis of simulation models of the ORC engine and takes into account some technical limitations such as the allowed operating ranges and the technical maturity of the components. The final configuration includes a diaphragm pump, two plate heat exchangers for the regenerator and the evaporator, an air-cooled condenser, two hermetic scroll expanders in series and R245fa as the working fluid. Simulations indicate that an efficiency close to 12% for the ORC engine can be reached for evaporating and condensing temperatures of 140 and 358C, respectively. [less ▲]

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See detailDESIGN OF A SMALL-SCALE ORGANIC RANKINE CYCLE ENGINE USED IN A SOLAR POWER PLANT
Declaye, Sébastien ULg; Georges, Emeline ULg; Bauduin, Maxime ULg et al

in Proceedings of Heat Powered Cycles Conference 2012 (2012, September)

Under the economical and political pressure due to the depletion of fossil fuel and global warming potential, it is necessary to develop more sustainable techniques to provide electrical power. In this ... [more ▼]

Under the economical and political pressure due to the depletion of fossil fuel and global warming potential, it is necessary to develop more sustainable techniques to provide electrical power. In this context, medium and large scale Organic Rankine Cycle solar power plants appear to be a promising solution because of their good efficiency, robustness and acceptable economical probability. However, only a few ORC solar power plants are in operation today, but technical literature indicate that several demonstration projects are under development. The spreading out of that technology requires, among others, a good knowledge of control strategies of the entire plant comprising the field of parabolic trough collectors, the ORC engine and thermal storage systems. The present project aims at designing, building and testing a small scale ORC solar power plant (a few kWe) in order to define and optimize control strategies that could be applied to larger systems. The paper presents the design step of the solar power plant, and more specifically the ORC engine. This design is defined based on simulation models of the ORC engine and on the experience gained in the Thermodynamics laboratory in the field of testing small-scale ORC systems. The design accounts for technical limitations such as allowed operating ranges and technical maturity of components. The paper first presents the architecture of the envisioned solar plant. The choice of the different technologies of components is justified. Simulation models of components (scroll expander, plate and fin-and-tubes heat exchangers, etc.) and of the whole system are then presented. Based on those models, parametric studies are conducted in order to optimize the sizing and the operating conditions of the system and to select the most appropriate working fluid. Also, the relevance of using two expanders in series is discussed and the control of the ORC engine is investigated. Simulations indicate that ORC engine efficiency close to 12% can be reached for evaporating and condensing temperatures of 140°C and 35°C. [less ▲]

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See detailDesign of a spherical array of microphones for room acoustics applications.
Feron, Hermine; Embrechts, Jean-Jacques ULg

Conference (2014, May 28)

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See detailDesign of a sprayer that makes CE-ESI-MS easy and robust
Far, Johann ULg; De Pauw, Edwin ULg; Falmagne, Jean-Bernard et al

Conference (2014, May 28)

Presentation of a CEMS interface design for easy and robust coupling of Capillary Electrophoresis with Mass Spectrometry equipped with a nanospray source. Principles and specification were presented.

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See detailDesign of a Stable Lagrange Multiplier Space for Stiff Boundary Conditions
Béchet, Eric ULg; Moës, Nicolas; Wohlmuth, Barbara

in Zilian, A.; Fries, T. P. (Eds.) International Conference on Extended Finite Element Methods – Recent Developments and Applications XFEM 2009 (2009)

We introduce a new algorithm to define a stable Lagrange multiplier space to impose stiff interface conditions within the context of the eXtended Finite Element Method. In contrast to earlier approaches ... [more ▼]

We introduce a new algorithm to define a stable Lagrange multiplier space to impose stiff interface conditions within the context of the eXtended Finite Element Method. In contrast to earlier approaches, we do not work with an interior penalty formulation as, e.g., for Nitsche techniques, but impose the constraints weakly in terms of Lagrange multipliers. The new algorithm allows a local construction of the Lagrange multiplier space while improving the accuracy of the computed fields. The originality of this approach with regard to former approaches lies in the use of the trace of primary shape functions defined on the domain, and a simplified procedure to define the mesh on the interface. Moreover, the newly constructed Lagrange multiplier space satisfies, in contrast to the naive approach, a uniform inf-sup condition. [less ▲]

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See detailDesign of a stable LM space for stiff boundary conditions and interfacial constraints
Béchet, Eric ULg

Scientific conference (2008, October)

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See detailDesign of a versatile device for measuring whole plant gas exchanges in Arabidopsis thaliana
Tocquin, Pierre ULg; Périlleux, Claire ULg

in New Phytologist (2004), 162(1), 223-229

Because of its small size and rosette growth habit, measuring gas exchanges in Arabidopsis thaliana is difficult with standard leaf cuvettes. Here, we designed a versatile system that is usable at the ... [more ▼]

Because of its small size and rosette growth habit, measuring gas exchanges in Arabidopsis thaliana is difficult with standard leaf cuvettes. Here, we designed a versatile system that is usable at the whole rosette level, as small as possible for fast and accurate measurements, but adaptable to plant size, and suitable for in situ measurements whatever the growing substrate of the plant. This cuvette is in two parts: the basic unit, which contains the sensors and is connected to the infra-red gas analyzer, and the clear chamber, where the rosette is enclosed. We made a set of three interchangeable chambers of different sizes to measure the rate of CO2 assimilation [A] of 26-, 33- and 40-d-old plants. The dependence of A to light irradiance and to intercellular CO2 concentration was recorded as typical response curves, which validate our device. Measurements were not only consistent in saturating conditions, but accurate CO2 exchange measurements in limiting conditions also reflected important physiological features related to plant ageing. [less ▲]

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See detailDesign of a watercourse and riparian strip monitoring system for environmental management
Debruxelles, N.; Claessens, Hugues ULg; Lejeune, Philippe ULg et al

in Environmental Monitoring & Assessment (2009), 156

Watercourses are complex ecosystems where numerous economic, ecological and heritage issues converge. To ensure their efficient management it is essential to have a full description of these ... [more ▼]

Watercourses are complex ecosystems where numerous economic, ecological and heritage issues converge. To ensure their efficient management it is essential to have a full description of these multifunctional ecosystems and to know their evolution over time. This paper describes a method for monitoring watercourses and their riparian strips developed in Wallonia (southern Belgium). It is based on an inventory constructed by stratified random sampling comprising 1,071 sampling plots distributed over a total length of 24,600 km of watercourses covered from their source. Each sampling plot is surveyed and measurements and fine observations are made on watercourse segments 50 m long. The method developed, which was applied on a regional scale, could easily be transposed to other entities, from large river basins, to an entire country. Examples of results obtained from a first inventory phase demonstrate the utility of this tool designed to supply qualitative and quantitative information to assist watercourse management. [less ▲]

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See detailDesign of an AC susceptometer based on a cryocooler
Vanderbemden, Philippe ULg

in Cryogenics (1998), 38(8), 839-842

This paper describes a simple and low-cost experimental setup intended for low temperature measurements under a time-dependent magnetic field. A typical application of this system is the determination of ... [more ▼]

This paper describes a simple and low-cost experimental setup intended for low temperature measurements under a time-dependent magnetic field. A typical application of this system is the determination of A.C. susceptibility and flux profiles of high-T-c superconductors. The A.C. magnetic field is generated by a sheeted iron-cored electromagnet. The device is based on a commercial closed-cycle helium refrigerator. A sample holder made of a polycrystalline silicon rod is shown to establish a good thermal contact between the sample and the cold head; it allows temperatures down to 20 K to be achieved. Experimental details are described and illustrative measurements on high-T-c superconductors are included. The performances and limitations of this system are discussed. (C) 1998 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailDesign of an Algebraic Neural Operating System in Programmable Logical Controller for Simulation and Execution of Sequential Operations
Dubois, Daniel ULg; Mascia, Antonio

in International Journal of Computing Anticipatory Systems [=IJCAS] (2010), 25

This paper deals with a general method for the analysis and the logical generation of discrete systems in Programmable Logical Controller (PLC). The Boolean operators are implemented with a generic and ... [more ▼]

This paper deals with a general method for the analysis and the logical generation of discrete systems in Programmable Logical Controller (PLC). The Boolean operators are implemented with a generic and unique algebraic model as event-dependent discrete equations, which can be executed in a sequential order. With this method, a generator of sequential logical tables can be designed, simulated and executed for implementing discrete dynamical systems. Two applications are studied. The first application deals with the industrial automation of a water supply for a factory. From the logical table of the events, an algebraic model is designed with a set of discrete equations. From these digital equations, a neural network of the water supply is built. The second application deals with an industrial traveling wagon. [less ▲]

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See detailDesign of an axial mechanical gas seal with self-acting lift geometry
DOCQUIER, N.; NELIS, M.; Bozet, Jean-Luc ULg

in European Journal of Mechanical and Environmental Engineering [=EJMEE] (1998), 43(no4), 195-203

Cet article étudie le comportement d'un joint mécanique sans contact à faces radiales, doté d'un dispositif d'augmentation de portance. La répartition des pressions et des vitesses dans le film mince est ... [more ▼]

Cet article étudie le comportement d'un joint mécanique sans contact à faces radiales, doté d'un dispositif d'augmentation de portance. La répartition des pressions et des vitesses dans le film mince est établie grâce à l'équation de Reynolds résolue au moyen de différences finies. L'étude paramétrique des caractéristiques du joint est ensuite réalisée en vue d'en déduire des abaques de fonctionnement et, par la suite, une démarche cohérente de choix des dimensions. L'auteur présente donc tout d'abord le fonctionnement d'un joint mécanique à gaz et il en décrit la géométrie et les conditions de travail. Après avoir défini et justifié les hypothèses utilisées, il propose une mise en équation du problème et décrit le comportement du système d'étanchéité en régime au moyen des résultats obtenus. L'article présente finalement l'influence de la géométrie du joint et propose une méthode de dimensionnement. [less ▲]

Detailed reference viewed: 16 (0 ULg)