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 detailA Distributed Lattice Boltzmann-based Flow Simulator
Dethier, Gérard ULiege

Conference (2009, January 22)

The use of Lattice Boltzmann (LB) methods is interesting to describe flows through complex geometries encountered in Chemical Engineering (porous media, packed beds, multi phase flows). However, flow ... [more ▼]

The use of Lattice Boltzmann (LB) methods is interesting to describe flows through complex geometries encountered in Chemical Engineering (porous media, packed beds, multi phase flows). However, flow simulations based on LB methods can require big amounts of memory. It is not always possible to run a simulation on a single machine. Distributed computing is a solution to this problem and also accelerates the execution of the flow simulation. In the context of dynamic heterogeneous clusters, the available machines can have different computational powers. The computational power of each machine can vary during a flow simulation (because of background load). Also, the number of available machines can change. These characteristics impose the use of special technics. Dynamic Load Balancing allows the optimal use of available machines. A fault occurs when one or several machines interrupt the execution of the distributed software component they were executing. Checkpointing makes the system fault tolerant. In order to obtain a scalable software and to suppress single points of failure, a special effort is made to decentralize as much as possible the software components of the simulator. Currently, fluid flows of 400³ points (more than 9 GBytes of data) are simulated using an heterogeneous cluster of 54 machines. [less ▲]

Detailed reference viewed: 129 (27 ULiège)
Full Text
Peer Reviewed
See detailDistributed learning: Developing a predictive model based on data from multiple hospitals without data leaving the hospital – A real life proof of concept
JOCHEMS, Arthur; DEIST, Timo M.; VAN SOEST, Johan et al

in Radiotherapy & Oncology (2016)

Purpose: One of the major hurdles in enabling personalized medicine is obtaining sufficient patient data to feed into predictive models. Combining data originating from multiple hospitals is difficult ... [more ▼]

Purpose: One of the major hurdles in enabling personalized medicine is obtaining sufficient patient data to feed into predictive models. Combining data originating from multiple hospitals is difficult because of ethical, legal, political, and administrative barriers associated with data sharing. In order to avoid these issues, a distributed learning approach can be used. Distributed learning is defined as learning from data without the data leaving the hospital. Patients and methods:Clinical data from 287 lung cancer patients, treated with curative intent with chemoradiation (CRT) or radiotherapy (RT) alone were collected from and stored in 5 different medical institutes (123 patients at MAASTRO (Netherlands, Dutch), 24 at Jessa (Belgium, Dutch), 34 at Liege (Belgium, Dutch and French), 48 at Aachen (Germany, German) and 58 at Eindhoven (Netherlands, Dutch)). A Bayesian network model is adapted for distributed learning (watch the animation: http://youtu.be/nQpqMIuHyOk). The model predicts dyspnea, which is a common side effect after radiotherapy treatment of lung cancer. Results:We show that it is possible to use the distributed learning approach to train a Bayesian network model on patient data originating from multiple hospitals without these data leaving the individual hospital. The AUC of the model is 0.61 (95%CI, 0.51–0.70) on a 5-fold cross-validation and ranges from 0.59 to 0.71 on external validation sets. Conclusion: Distributed learning can allow the learning of predictive models on data originating from multiple hospitals while avoiding many of the data sharing barriers. Furthermore, the distributed learning approach can be used to extract and employ knowledge from routine patient data from multiple hospitals while being compliant to the various national and European privacy laws. [less ▲]

Detailed reference viewed: 19 (0 ULiège)
Full Text
Peer Reviewed
See detailDistributed load interruption and shedding against voltage delayed recovery or instability
Otomega, Bogdan; Van Cutsem, Thierry ULiege

in Proc. IEEE PES 2013 PowerTech Conference (2013, June)

This paper deals with a two-part system integrity protection scheme to be installed in distribution networks, to counteract fault-induced delayed voltage recovery or even short-term voltage instability ... [more ▼]

This paper deals with a two-part system integrity protection scheme to be installed in distribution networks, to counteract fault-induced delayed voltage recovery or even short-term voltage instability due to induction motors. The first part consists of a fast triggered but temporary reduction of some loads to facilitate motor re-acceleration after fault clearing. The second part resorts to load shedding, as a back-up. The scheme relies on purely distributed controllers; each of them measures a bus voltage and interrupts/disconnects load at the same bus. Tests have been performed on a generic MV/LV system. They illustrate the benefit of load interruption and the selectivity of the proposed scheme. [less ▲]

Detailed reference viewed: 113 (6 ULiège)
Full Text
Peer Reviewed
See detailDistributed Model-free Control of Photovoltaic Units for Mitigating Overvoltages in Low-Voltage Networks
Aristidou, Petros ULiege; Olivier, Frédéric ULiege; Hervas, Maria Emilia et al

in Proc. of CIRED 2014 workshop (2014, June)

In this paper, a distributed model-free control scheme to mitigate overvoltage problems caused by high photovoltaic generation in low-voltage feeders is proposed. The distributed controllers are ... [more ▼]

In this paper, a distributed model-free control scheme to mitigate overvoltage problems caused by high photovoltaic generation in low-voltage feeders is proposed. The distributed controllers are implemented on the photovoltaic inverters and modulate the active and reactive power injected into the network. In particular, they direct photovoltaic units first to consume reactive power and, if necessary, curtail active power generation to reduce high voltages in the feeder. [less ▲]

Detailed reference viewed: 183 (31 ULiège)
Full Text
Peer Reviewed
See detailDistributed MPC of wide-area electromechanical oscillations of large-scale power systems
Wang, Da ULiege; Glavic, Mevludin; Wehenkel, Louis ULiege

in Proceedings of ISAP 2011 (2011, September)

We investigate distributed Model Predictive Control (MPC) to damp wide-area electromechanical oscillations. Our distributed MPC schemes are derived from and compared with a fully centralized MPC scheme ... [more ▼]

We investigate distributed Model Predictive Control (MPC) to damp wide-area electromechanical oscillations. Our distributed MPC schemes are derived from and compared with a fully centralized MPC scheme proposed in a previous publication. Based on simulations carried out using a 16-generator, 70-bus, two-area test power system, we show that simple coordination schemes based on additional local measurements’ feedback yield already a significant improvement with respect to a scheme with only implicit coordination, improve significantly with respect to purely local controls, and in this respect reach about 75% of the improvements obtained by an ideal centralized MPC scheme. [less ▲]

Detailed reference viewed: 35 (5 ULiège)
See detailA Distributed Signal Processing Architecture
Filip, A. E.; Arthur, James S.; Drinan, John D. et al

Report (1983)

Detailed reference viewed: 3 (0 ULiège)
Full Text
Peer Reviewed
See detailA distributed stream temperature model using high resolution temperature observations
Westhoff, Martijn ULiege; Savenije, H. H. G.; Luxemburg, W. M. J. et al

in Hydrology and Earth System Sciences (2007), 11(4), 1469-1480

Detailed reference viewed: 8 (1 ULiège)
Full Text
Peer Reviewed
See detailDistributed Training Enhances Implicit Sequence Acquisition in Children With Specific Language Impairment
Desmottes, Lise ULiege; Meulemans, Thierry ULiege; Patinec, Marie-Aude et al

in Journal of Speech, Language, and Hearing research (2017)

Purpose This study explored the effects of 2 different training structures on the implicit acquisition of a sequence in a serial reaction time (SRT) task in children with and without specific language ... [more ▼]

Purpose This study explored the effects of 2 different training structures on the implicit acquisition of a sequence in a serial reaction time (SRT) task in children with and without specific language impairment (SLI). Method All of the children underwent 3 training sessions, followed by a retention session 2 weeks after the last session. In the massed-training condition, the 3 training sessions were in immediate succession on 1 day, whereas in the distributed-training condition, the 3 training sessions were spread over a 1-week period in an expanding schedule format. Results Statistical analyses showed that the children with normal language were unaffected by the training conditions, performing the SRT task similarly in both training conditions. The children with SLI, however, were affected by the training structure, performing the SRT task better when the training sessions were spaced over time rather than clustered on 1 day. Conclusion This study demonstrated that although intensive training does not increase learning in children with SLI, distributing training sessions over time does increase learning. The implications of these results on the learning abilities of children with SLI are discussed, as are the mechanisms involved in massed versus distributed learning. [less ▲]

Detailed reference viewed: 45 (1 ULiège)
Full Text
Peer Reviewed
See detailDistributed undervoltage load shedding
Otomega, Bogdan; Glavic, Mevludin; Van Cutsem, Thierry ULiege

in IEEE Transactions on Power Systems (2007), 22(4), 2283-2284

A new design of load shedding against long-term voltage instability is proposed. It uses a set of distributed controllers, each monitoring a transmission voltage, controlling a group of loads, acting in ... [more ▼]

A new design of load shedding against long-term voltage instability is proposed. It uses a set of distributed controllers, each monitoring a transmission voltage, controlling a group of loads, acting in closed-loop, and adjusting its action to the voltage evolution. The whole system operates without information exchange between controllers. [less ▲]

Detailed reference viewed: 139 (2 ULiège)
Full Text
See detailDe distributie van goederen en de licentieovereenkomst
Vanbrabant, Bernard ULiege; Van Couter, Yves

in Bestendig Handboek Distributierecht (2007)

Detailed reference viewed: 62 (4 ULiège)
Full Text
Peer Reviewed
See detailDistributing the Optical Near-Field for Efficient Field-Enhancements in Nanostructures
Valev, V; De Clercq, B; Biris, C et al

in Advanced Materials (2012), 24

Circularly polarized light imparts a sense of rotation on the electron density in ring-shaped gold nanostructures. As a consequence, the near-field enhancement becomes homogeneous on the surface of the ... [more ▼]

Circularly polarized light imparts a sense of rotation on the electron density in ring-shaped gold nanostructures. As a consequence, the near-field enhancement becomes homogeneous on the surface of the nanostructures, thereby increasing the opportunity for interaction with molecules. This type of nanostructured samples can find a broad range of applications in chemical processes where the interaction between molecules and local field enhancements play an important role. [less ▲]

Detailed reference viewed: 24 (2 ULiège)
Full Text
Peer Reviewed
See detailDistribution amplitude for the photon-pion transition
Courtoy, Aurore ULiege; Noguera, S.

in PoS - Proceedings of Science (2008), LC2008

Detailed reference viewed: 10 (0 ULiège)
Peer Reviewed
See detailDistribution and accumulation pattern of perfluorooctane sulfonic acid (PFOs) in marine mammals from the North Sea
Van de Vijver, Kristin; Das, Krishna ULiege; Van Dongen, W. et al

Poster (2002, November)

Detailed reference viewed: 25 (3 ULiège)
Full Text
See detailDistribution and activity of chitinolytic enzymes in the digestive tract of birds and mammals
Jeuniaux, Charles ULiege; Cornelius, C.

Scientific conference (1997, April)

The extraction and purification of chitinolytic enzymes devoid of any lysozymic activity, taken from the gastric mucosa of mamals, indicated that these enzymes are true chitinases, rather than lysozymes ... [more ▼]

The extraction and purification of chitinolytic enzymes devoid of any lysozymic activity, taken from the gastric mucosa of mamals, indicated that these enzymes are true chitinases, rather than lysozymes with chitinolytic activity. A close relationship was found between chitinase secretions in the digestive tract and the nature of the normal diet of the species considered. Changing the diet of an animal (mouse, rat, hamster, guinea pig) for a few weeks did not modify its ability or inability to secrete chitinase. In the digestive tract of birds, chitinase is secreted only by the gtastric mucosa. All the more or less insectivorous birds so far studied, including chickens, do secrete gastric chitinases. No chitinase secretion was dected in the pigeon or the parrot. In mammals, gastric chitinases were found in omnivorous and insectivorous species belonging to the orders Insectivora, Chiroptera, Carnivora, Rodenta and primates. in the pig, chitinases are secreted by the gastric mucosa and by the pancreas. The digestibility of chitin in both a purified and a natural form was estimated in feeding experiments with mice, Japanese nightingales and chickens. From 19% to 58% chitin was digested by mice and chickens that were fed a diet containing pure chitin, and by Japanese nightingales that were fed mealworm larvae. [less ▲]

Detailed reference viewed: 61 (5 ULiège)
Full Text
Peer Reviewed
See detailDistribution and air-water exchange of carbon dioxide in the Scheldt plume off the Belgian coast
Borges, Alberto ULiege; Frankignoulle, Michel

in Biogeochemistry (2002), 59((1-2)), 41-67

In the present paper we report partial pressure of CO2 (pCO2) data obtained off the Belgian coast during 24 cruises. The temporal and spatial resolution of this data set allows us to discuss ... [more ▼]

In the present paper we report partial pressure of CO2 (pCO2) data obtained off the Belgian coast during 24 cruises. The temporal and spatial resolution of this data set allows us to discuss satisfactorily seasonal and inter-annual variability of pCO2 in the study area. The dynamics of pCO2 are described using two approaches: fixed reference stations and area survey cruises. The air-water fluxes of CO2 in the Scheldt estuarine plume and in the outerplume region are estimated quantitatively, showing that these areas correspond respectively to a net annual source and sink of atmospheric CO2. The annually integrated air-water fluxes for the Scheldt estuarine plume range between +1.1 and +1.9 mol m−2 year−1 as a function of the formulation of the exchange coefficient of CO2. The annual net emission of CO2 from the estuarine plume to the atmosphere is estimated to be between +2.3 to +4.0 Gmol year−1 which represents 17 to 29% of the estimate reported in the literature for the Scheldt inner estuary. [less ▲]

Detailed reference viewed: 22 (2 ULiège)
Full Text
Peer Reviewed
See detailDistribution and characteristics of aquatic habitats of newts and yellow-bellied toads in the district of Ioannina (Epirus, Greece)
Denoël, Mathieu ULiege

in Herpetozoa (2004), 17(1/2), 49-64

The study describes the aquatic habitats and distribution of Triturus alpestris veluchiensis Wolterstorff 1935, T. carnifex macedonicus (Karaman, 1922), T. vulgaris graecus (Wolterstorff, 1905) and ... [more ▼]

The study describes the aquatic habitats and distribution of Triturus alpestris veluchiensis Wolterstorff 1935, T. carnifex macedonicus (Karaman, 1922), T. vulgaris graecus (Wolterstorff, 1905) and Bombina variegata scabra (Küster, 1843) in the district (“nomos”) of Ioannina, Northern Greece. Bombina variegata was found to be the most common species, followed by T. alpestris and T. carnifex while T. vulgaris seemed to be rare. The four taxa differed in habitat use and geographic distribution. Records of T. alpestris were limited to the highest sites in the north and east of the district. This species inhabited alpine lakes, but also smaller habitats such as drinking troughs and ponds. Four populations contained paedomorphic individuals. Triturus vulgaris appeared to be restricted to low altitude sites in the centre of the district where it lived in reservoirs, watering basins and drinking troughs. Triturus carnifex and B. variegata had a wider distribution and occupied a broader spectrum of habitats. Bombina variegata was the only species studied which lived in running waters (small brooks). Neither newts nor yellow-bellied toads were found in large rivers and lakes. In the district of Ioannina both habitat variety and distribution range of newts and Yellow-bellied Toads turned out to be greater than previously known. Alpine lakes containing very large populations of paedomorphic individuals should be protected given the rarity of the phenomenon. [less ▲]

Detailed reference viewed: 1309 (7 ULiège)
See detailDistribution and composition of organic carbon in the Tana River Basin, (Kenya)
Tamooh, F.; van den Meersche, K.; Borges, Alberto ULiege et al

Poster (2011)

Detailed reference viewed: 33 (1 ULiège)
See detailDistribution and composition of organic carbon in the Tana River Basin, (Kenya)
Tamooh, F.; van den Meersche, K.; Borges, Alberto ULiege et al

Conference (2011, February 13)

Detailed reference viewed: 9 (0 ULiège)