Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
Full Text
Peer Reviewed
See detailPassive solar buildings : development and evaluation of a model-based optimal controller through experimentation and simulation.
Andre, Philippe ULg; Kummert, M.

in Proceedings of the International conference Energy efficient technologies in indoor environment (2005, September)

Different heating system controllers for passive solar buildings are compared on two different buildings. The performance criterion combines energy performance and thermal comfort using the "cost function ... [more ▼]

Different heating system controllers for passive solar buildings are compared on two different buildings. The performance criterion combines energy performance and thermal comfort using the "cost function" paradigm. The experimental facilities did not allow a direct experimental comparison by using two identical buildings. The controllers were implemented alternatively in one building and a performance comparison was obtained in two ways: first by identifying short periods that have similar driving variables (weather and building occupancy) and comparing the experimental obtained in both cases. The second method mixes experiments and simulation using a well-tuned model of the building and its occupants. This paper discusses the results obtained using both methods and shows that both methods give consistent estimates of the difference between controllers, while the second method allows to extrapolate useful information from the limited data available. In a second evaluation step the controller is applied to a multizone building, and a detailed model is used for the HVAC system. The model-based control algorithm is not modified. It is based on a simplified internal model. It is shown that the optimal controller's performance varies strongly with the zone that is considered and the reference zone that is used. However, it is never worse than the performance of a reference controller. The global performance at the building level depends on the selected reference zone and on the building sensitivity to overheating. [less ▲]

Detailed reference viewed: 16 (0 ULg)
Full Text
See detailPASSIVE SUPPRESSION OF AEROELASTIC INSTABILITIES OF IN-FLOW WINGS BY TARGETED ENERGY TRANSFERS TO LIGHTWEIGHT ESSENTIALLY NONLINEAR ATTACHMENTS
lee, Young S.; Vakakis, Alexander F.; Bergman, Lawrence A. et al

in International Forum on Aerolasticity and Strucural Dynamics, Stockholm, 2007 (2007)

Theoretical and experimental suppression of aeroelastic instabilities by means of broadband passive targeted energy transfers has been recently studied. A single-degree-offreedom (SDOF) nonlinear energy ... [more ▼]

Theoretical and experimental suppression of aeroelastic instabilities by means of broadband passive targeted energy transfers has been recently studied. A single-degree-offreedom (SDOF) nonlinear energy sink (NES) was coupled to a 2-DOF rigid wing modeled in the low-speed, subsonic regime with quasi-steady aerodynamic theory. The nonlinear attachment was designed and optimized to suppress the critical nonlinear modal energy exchanges between the flow and the (pitch and heave) wing modes, thus suppressing the (transient) triggering mechanism of aeroelastic instability. We performed bifurcation analysis to find regions of robust passive aeroelastic suppression in parameter space. Then, we employed multi-degreeof-freedom nonlinear energy sinks (MDOF NESs) to improve robustness of the aeroelastic instability suppression. Bifurcation analysis by a numerical continuation technique demonstrated that controlling the occurrence of a limit point cycle (LPC or saddle-node) bifurcation point above a Hopf bifurcation point is crucial to enhancing suppression robustness. MDOF NESs not only can enhance robustness of suppression against even strong gust-like disturbances, but they require lower NES mass compared to SDOF NES designs. The validity of the theoretical findings was proven by a series of wind tunnel experiments. [less ▲]

Detailed reference viewed: 100 (0 ULg)
Peer Reviewed
See detailPassive target classification based on low-frequency bistatic backscattering coefficients
Pisane, Jonathan ULg; Lesturgie, Marc; Verly, Jacques ULg

Conference (2010, June)

In this paper, we describe a new automatic target recognition method for classifying targets according to their bistatic backscattering coefficients. The classification model is based on the construction of ... [more ▼]

In this paper, we describe a new automatic target recognition method for classifying targets according to their bistatic backscattering coefficients. The classification model is based on the construction of subspaces, one per target class. Results show an overall correct classification rate of about 83%, indicating that our method seems to be valid. Further improvements of the algorithm are also discussed. [less ▲]

Detailed reference viewed: 31 (7 ULg)
Full Text
Peer Reviewed
See detailPassive temperature tomography experiments to characterize transmissivity and connectivity of preferential flow paths in fractured media
Klepikova, Maria ULg

in Journal of Hydrology (2014)

The detection of preferential flow paths and the characterization of their hydraulic properties are major challenges in fractured rock hydrology. In this study, we propose to use temperature as a passive ... [more ▼]

The detection of preferential flow paths and the characterization of their hydraulic properties are major challenges in fractured rock hydrology. In this study, we propose to use temperature as a passive tracer to characterize fracture connectivity and hydraulic properties. In particular, we propose a new temperature tomography field method in which borehole temperature profiles are measured under different pumping conditions by changing successively the pumping and observation boreholes. To interpret these temperature-depth profiles, we propose a three step inversion-based framework. We consider first an inverse model that allows for automatic permeable fracture detection from borehole temperature profiles under pumping conditions. Then we apply a borehole-scale flow and temperature model to produce flowmeter profiles by inversion of temperature profiles. This second step uses inversion to characterize the relationship between temperature variations with depth and borehole flow velocities (Klepikova et al., 2011). The third inverse step, which exploits cross-borehole flowmeter tests, is aimed at inferring inter-borehole fracture connectivity and transmissivities. This multi-step inverse framework provides a means of including temperature profiles to image fracture hydraulic properties and connectivity. We test the proposed approach with field data obtained from the Ploemeur (N.W. France) fractured rock aquifer, where the full temperature tomography experiment was carried out between three 100 m depth boreholes 10 m apart. We identified several transmissive fractures and their connectivity which correspond to known fractures and corroborate well with independent information, including available borehole flowmeter tests and geophysical data. Hence, although indirect, temperature tomography appears to be a promising approach for characterizing connectivity patterns and transmissivities of the main flow paths in fractured rock. [less ▲]

Detailed reference viewed: 19 (8 ULg)
Full Text
Peer Reviewed
See detailPassive temperature tomography experiments to characterize transmissivity and connectivity of preferential flow paths in fractured media
Klepikova, Maria ULg

in Journal of Hydrology (2014)

The detection of preferential flow paths and the characterization of their hydraulic properties are major challenges in fractured rock hydrology. In this study, we propose to use temperature as a passive ... [more ▼]

The detection of preferential flow paths and the characterization of their hydraulic properties are major challenges in fractured rock hydrology. In this study, we propose to use temperature as a passive tracer to characterize fracture connectivity and hydraulic properties. In particular, we propose a new temperature tomography field method in which borehole temperature profiles are measured under different pumping conditions by changing successively the pumping and observation boreholes. To interpret these temperature-depth profiles, we propose a three step inversion-based framework. We consider first an inverse model that allows for automatic permeable fracture detection from borehole temperature profiles under pumping conditions. Then we apply a borehole-scale flow and temperature model to produce flowmeter profiles by inversion of temperature profiles. This second step uses inversion to characterize the relationship between temperature variations with depth and borehole flow velocities (Klepikova et al., 2011). The third inverse step, which exploits cross-borehole flowmeter tests, is aimed at inferring inter-borehole fracture connectivity and transmissivities. This multi-step inverse framework provides a means of including temperature profiles to image fracture hydraulic properties and connectivity. We test the proposed approach with field data obtained from the Ploemeur (N.W. France) fractured rock aquifer, where the full temperature tomography experiment was carried out between three 100 m depth boreholes 10 m apart. We identified several transmissive fractures and their connectivity which correspond to known fractures and corroborate well with independent information, including available borehole flowmeter tests and geophysical data. Hence, although indirect, temperature tomography appears to be a promising approach for characterizing connectivity patterns and transmissivities of the main flow paths in fractured rock. [less ▲]

Detailed reference viewed: 19 (8 ULg)
Peer Reviewed
See detailPast and Future CFC and other trace gas warming: results from a seasonal climate model
Hauglustaine, Didier A.; Gérard, Jean-Claude ULg

in Annales Geophysicae [= ANGEO] (1991), 9

Detailed reference viewed: 11 (5 ULg)
Full Text
See detailPast and future events specificity in bipolar disorders
Boulanger, Marie ULg; Lejeune, Aurélie; Blairy, Sylvie ULg

Poster (2009)

Previous research has shown that the individuals suffering from emotional disorders have specificity of autobiographical memory (AM) deficits. This difficulty to remember specific personal past events ... [more ▼]

Previous research has shown that the individuals suffering from emotional disorders have specificity of autobiographical memory (AM) deficits. This difficulty to remember specific personal past events seems related to difficulty to project specific oneself into the future (D’Argembeau, Raffard & Van der Linden, 2008). The aim of this study was investigated these impairments in population with bipolar disorders (BD). Participants (19 patients with bipolar disorders and 17 healthy subjects) completed validated French versions (Neumann & Philippot, 2006) of the AMT Williams & Broadbent (1986). Participants were instructed to generate specific past and future memories in response to cues words. For past events, the analyses revealed a significant group by memory interaction (F(2,68) = 4.0 ; p=.023) which indicates that the patients with BD recollected less specific events and more overgeneral events than controls. In the same way, for the future events task, a significant group by memory interaction emerged (F(2,68) = 7.85 ; p<.001) which indicates that the patients with BD were less specific and yielded more overgeneral memories than the control group. Thereby the results are consistent with previous studies that have examined autobiographical memory specificity in patients with BD (Scott et al., 2000; Mansell & Lam, 2004). However, to ours knowledges, the present study is the first to investigate specificity of AM and the abilities to generate specific events for future in patients with bipolar disorders. [less ▲]

Detailed reference viewed: 46 (4 ULg)
Full Text
Peer Reviewed
See detailThe Past Clouds the Future of Europe’s New Antitrust Enforcer
Petit, Nicolas ULg

Article for general public (2010)

Detailed reference viewed: 26 (3 ULg)
Full Text
Peer Reviewed
See detailPast into Future: Cyprus' Undivided Literature - AydIn Mehmet Ali and Stephanos Stephanides
Pagnoulle, Christine ULg

in Kunapipi : Journal of Postcolonial Writing (2012), 33(1-2), 202-214

The present article examines poems by Stephanides and short stories by Mehmet Ali (of Greek and Turkish origins respectively, as their names indicate), bringing out a common sensibility to loss and ... [more ▼]

The present article examines poems by Stephanides and short stories by Mehmet Ali (of Greek and Turkish origins respectively, as their names indicate), bringing out a common sensibility to loss and yearning for reconciliation. In keeping with what is brought out throughout this remarkable double issue edited by Anne Collett it stresses the underlying unity in hte island's literature. [less ▲]

Detailed reference viewed: 131 (45 ULg)
Full Text
Peer Reviewed
See detailPast, present and future of nonlinear system identification in structural dynamics
Kerschen, Gaëtan ULg; Worden, Keith; Vakakis, Alexander F. et al

in Mechanical Systems & Signal Processing (2006), 20(3), 505-592

This survey paper contains a review of the past and recent developments in system identification of nonlinear dynamical structures. The objective is to present some of the popular approaches that have ... [more ▼]

This survey paper contains a review of the past and recent developments in system identification of nonlinear dynamical structures. The objective is to present some of the popular approaches that have been proposed in the technical literature, to illustrate them using numerical and experimental applications, to highlight their assets and limitations and to identify future directions in this research area. The fundamental differences between linear and nonlinear oscillations are also detailed in a tutorial. (c) 2005 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 62 (5 ULg)
Full Text
Peer Reviewed
See detailPasteurella Multocida isolation in a horse with retropharyngeal infection
Amory, Hélène ULg; Jean, D.; Leveille, R. et al

in Journal of Equine Veterinary Science (2006), 26(8), 364-369

Retropharyngeal infections in horses normally induce local painful swelling of the retropharyngeal area, which may lead to dyspnea, dysphagia, and systemic manifestations. Differential diagnosis of local ... [more ▼]

Retropharyngeal infections in horses normally induce local painful swelling of the retropharyngeal area, which may lead to dyspnea, dysphagia, and systemic manifestations. Differential diagnosis of local painful swelling of the retropharyngeal area includes retropharyngeal lymph node infection, neoplasm, cellulitis, hematoma, guttural pouch empyema, parotiditis, and jugular thrombosis. Apart from Streptococcus equi ssp. equi, other bacteria are rarely reported as a cause of retropharyngeal abscesses. The reason for this might be a lack of specific sampling to identify the causative agent. This work deals with a case of retropharyngeal infection in an 11-year-old Standardbred stallion with acute depression, fever, tachycardia, asymmetric painful swelling in the throat area, ptyalism, and respiratory distress. Endoscopy, radiography, ultrasonography, blood analysis, and cytological examination of a puncture sample taken from the throat mass were consistent with a pyogenic to pyogranulomatous retropharyngeal inflammation. The clinical evolution was initially satisfactory in response to treatment with nonsteroidal antiinflammatory drugs and antibiotics, but clinical signs relapsed twice, each time a few weeks after cessation of antibiotic therapy. The bacteriologic finding in this case was unusual and consisted of the isolation of a Pasteurella multocida strain that was obtained after the second relapse (ie, 79 days after initial admission), using a brain heart infusion (BHI) medium, and after two successive negative bacteriological cultures performed on day one of clinical signs and at the first relapse of clinical signs, respectively. [less ▲]

Detailed reference viewed: 23 (0 ULg)
Full Text
See detailPastoral dynamics in the Region of Diffa (Niger) : a descriptive analysis of livestock capital
Rouchet, François ULg; Abdoulkadri, Laouali; Lebailly, Philippe ULg et al

Conference (2013, October 05)

Detailed reference viewed: 20 (8 ULg)
Full Text
Peer Reviewed
See detailPastoral dynamics in the region of Diffa (Niger) : a descriptive analysis of livestock capital
Laouali, Abdoulkadri ULg; Rouchet, François ULg; Lebailly, Philippe ULg et al

in Dusan Kovacevic, Kovacevic (Ed.) Book of proceedings - Fourth International Scientific Symposium „Agrosym 2013“ (2013)

Located between the desert zone in the North and the Sahelian zon in the South, the Region of Diffa is a pastoral area par excellence in Niger. Breeding, witch a highly diversified livestock, is the ... [more ▼]

Located between the desert zone in the North and the Sahelian zon in the South, the Region of Diffa is a pastoral area par excellence in Niger. Breeding, witch a highly diversified livestock, is the dominant economic activity in the region. It occupied 95% of the population and contributes annually to 55% in the formation of the region gross domestic production. For understanding the pastoral dynamic a survey of 300 households (150 households witch herd sedentary and 150 witch herd mobile) was conducted during the first semester of 2012. The data analysis is performed from a herd of 15,618 animal heads consisting mainly of small ruminants for both sedentary (72%) and mobile (52%). The herd structure (sedentary and mobile) by age and sex shows on the one hand, the males are early and systematically exploited, all species including, and the reproduction is carried out by a core of female spawners more less stable and dominated by young females, on the other hand. Comparative analysis of compositions and structures of the livestock by agro-ecological zone (Pastoral bowls zone; Komadougou River and Lake Chad zones) reveals zonal disparities particularly in the sedentary livestock system. [less ▲]

Detailed reference viewed: 38 (27 ULg)
See detailPat Buchanan et les paléoconservateurs
Jamin, Jérôme ULg

Scientific conference (2004)

Detailed reference viewed: 3 (0 ULg)
Full Text
Peer Reviewed
See detailPAT tools for the control of co-extrusion implants manufacturing process
Krier, Fabrice ULg; Mantanus, Jérome; Sacre, Pierre-Yves ULg et al

in International Journal of Pharmaceutics (2013), 458

Hot melt extrusion is a novel pharmaceutical manufacturing process technique. In this study, we identified four Critical Quality Attributes (CQAs) of the implant manufacturing process by hot melt ... [more ▼]

Hot melt extrusion is a novel pharmaceutical manufacturing process technique. In this study, we identified four Critical Quality Attributes (CQAs) of the implant manufacturing process by hot melt extrusion: the implant diameter, the quantity of the Active Pharmaceutical Ingredient (API), the homogeneity distribution of API and the thickness of the membrane. We controlled the implant diameter and the quantity of API in-line with a laser measurement, NIR and Raman spectroscopy, respectively. These two different spectroscopic techniques provided comparable results. In fact, the RMSEC and RMSECV were very close in each PAT technique but NIR spectroscopy was easier to use and less sensitive to external changes. For the control of the homogeneity of API distribution and the thickness of the membrane, we used successfully Raman spectroscopy imaging. These PAT tools help reducing analysis time. [less ▲]

Detailed reference viewed: 35 (17 ULg)
Full Text
Peer Reviewed
See detailPatch repair: compatibility issues
Garbacz, Andrzej; Courard, Luc ULg; Bissonnette, Benoît et al

in Grantham, Michael; Basheer, Muhammed; Magee, Bryan (Eds.) et al Proceedings of the 5th International Conference on Concrete Repair (2014)

Repair of any concrete structure results in formation of complex, at least two-component repair systems. Compatibility approach is treated as a basic requirement during selection of repair material ... [more ▼]

Repair of any concrete structure results in formation of complex, at least two-component repair systems. Compatibility approach is treated as a basic requirement during selection of repair material. Recently, the understanding for compatibility requirements in repair systems approach is demonstrated in many papers. The aim of this paper is analyzing the compatibility between repair materials and concrete substrate in the case of patch repair. The compatibility issues were discussed in light of the various requirements which determine the mathematical space of loads, including chemical, mechanical and other physical (mainly thermal) loads. N-dimensional compatibility space is created, taking into account selected patch material control parameters. The requirements for good compatibility between repair material and concrete substrate can be formulated by using mathematical inequalities, where the variables are the material control parameters. The effects of properties of the both repair material and concrete substrate were analyzed using computer system ANCOMP developed at Warsaw University of Technology. Usability of this approach was demonstrated using selected case study as an example. [less ▲]

Detailed reference viewed: 16 (0 ULg)
Full Text
Peer Reviewed
See detailPatch-clamp recording from mossy fiber terminals in hippocampal slices
Bischofberger, J; Engel, Dominique ULg; Li, L et al

in Nature Protocols (2006), 1(4), 2075-81

Detailed reference viewed: 3 (0 ULg)