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
See detailIntegration of geophysical data in hydrogeological models
Hermans, Thomas ULiege; Beaujean, Jean; Nguyen, Frédéric ULiege

Conference (2015, October 23)

Detailed reference viewed: 17 (1 ULiège)
See detailIntegration of III-V on Si for High-Mobility CMOS
Waldron, Niamh; Wang, Gang; Nguyen, Ngoc Duy ULiege et al

Conference (2012)

Detailed reference viewed: 97 (0 ULiège)
Full Text
Peer Reviewed
See detailIntegration of InGaAs Channel n-MOS Devices on 200mm Si Wafers Using the Aspect-Ratio-Trapping Technique
Waldron, Niamh; Wang, Gang; Nguyen, Ngoc Duy ULiege et al

in ECS Transactions (2012), 45

We report on the fabrication on InGaAs/InP implant free quantum well (IFQW) n-MOSFET devices on 200mm wafers in a Si CMOS processing environment. The starting virtual InP substrates were prepared by means ... [more ▼]

We report on the fabrication on InGaAs/InP implant free quantum well (IFQW) n-MOSFET devices on 200mm wafers in a Si CMOS processing environment. The starting virtual InP substrates were prepared by means of the aspect-ratio-trapping technique. Post CMP these substrate resulted in a planar substrate with a rms roughness of 0.32 nm. After channel and gate processing source drain regions were formed by the selective epitaxial growth of Si doped InGaAs. Contact to the source/drain regions was made by a standard W-plug/metal 1 process. The contact resistance was estimated to be on the order of 7x10-7 [ohm sign].cm2. Fully processed devices clearly showed gate modulation albeit on top of high levels of source to drain leakage. The source of this leakage was determined to be the result of the unintentional background doping of the InP buffer layer. Simulations show that the inclusion of the p-InAlAs between the InP and InGaAs can effectively suppress this leakage. This work is a significant step towards the integration of InGaAs based devices on a standard CMOS platform. [less ▲]

Detailed reference viewed: 94 (5 ULiège)
Peer Reviewed
See detailIntegration of InGaAs Channel n-MOS Devices on 200mm Si Wafers Using the Aspect-Ratio-Trapping Technique
Waldron, Niamh; Wang, Gang; Nguyen, Ngoc Duy ULiege et al

in 221st ECS Meeting (2012)

Detailed reference viewed: 44 (3 ULiège)
Full Text
Peer Reviewed
See detailIntegration of Inland Waterway Transport in the Intermodal Supply Chain: a Joint Research Agenda
Caris, An; Limbourg, Sabine ULiege; Macharis, Cathy et al

in Rigo, Philippe; Wolters, Milou (Eds.) Proceedings of the PIANC SMART Rivers Conference 2013 (2013)

This paper identifies research opportunities which will enable the further integration of inland waterway transport in the intermodal supply chain. Intermodal transport may be interpreted as a chain of ... [more ▼]

This paper identifies research opportunities which will enable the further integration of inland waterway transport in the intermodal supply chain. Intermodal transport may be interpreted as a chain of actors who supply a transport service. Inland navigation can play a crucial role in increasing supply chain service performance. A first group of research challenges has the objective to encourage efficient operations in IWT: development of a system wide model for IWT, integration of operational planning systems and analysis of bundling networks. A second group of research efforts is directed towards shippers and consignees who use the intermodal transport chain to send or receive their goods: further development of models that integrate intermodal transport decisions with supply chain decisions and creation of green supply chains. A third group of research challenges concerns the problem domain of external cost calculations. Finally detailed time series data on freight transport should be collected to support these future research tracks. [less ▲]

Detailed reference viewed: 89 (20 ULiège)
Full Text
Peer Reviewed
See detailIntegration of inland waterway transport in the intermodal supply chain: a taxonomy of research challenges
Caris, An; Limbourg, Sabine ULiege; Macharis, Cathy et al

in Journal of Transport Geography (2014), 41

This paper identifies research opportunities which will enable the further integration of inland waterway transport in the intermodal supply chain. Intermodal transport may be interpreted as a chain of ... [more ▼]

This paper identifies research opportunities which will enable the further integration of inland waterway transport in the intermodal supply chain. Intermodal transport may be interpreted as a chain of actors who supply a transport service. Inland navigation can play a crucial role in increasing supply chain service performance. A first group of research challenges lies in the evolving relationship between transport geography and logistics activities. The next set of research challenges has the objective to encourage efficient operations in IWT: development of a system wide model for IWT, integration of operational planning systems and analysis of bundling networks. A third group of research efforts is directed towards shippers and consignees who use the intermodal transport chain to send or receive their goods: further development of models that integrate intermodal transport decisions with supply chain decisions and creation of green supply chains. A fourth cluster of research challenges concerns the problem domain of external cost calculations. Finally detailed time series data on freight transport should be collected to support these future research tracks? [less ▲]

Detailed reference viewed: 81 (24 ULiège)
Full Text
See detailIntegration of longevity into the Walloon genetic evaluation system
Vanderick, Sylvie ULiege; Croquet, Coraline; Soyeurt, Hélène ULiege et al

Conference (2006, June)

Detailed reference viewed: 37 (5 ULiège)
Full Text
See detailIntegration of longevity into the Walloon genetic evaluation system
Vanderick, Sylvie ULiege; Croquet, Coraline; Soyeurt, Hélène ULiege et al

in Interbull Bulletin (2006), 35

Detailed reference viewed: 38 (5 ULiège)
See detailIntegration of Migrants from a comparative perspective
Martiniello, Marco ULiege

Scientific conference (2005, May 26)

Detailed reference viewed: 8 (0 ULiège)
Full Text
See detailIntegration of near-surface geophysical, geological and hydrogeological data with multiple-point geostatistics in alluvial aquifers
Hermans, Thomas ULiege

Doctoral thesis (2014)

Alluvial plains constitute essential geological bodies for environmental studies such as contaminated sites remediation, low-enthalpy geothermal energy or groundwater resources. The heterogeneity of these ... [more ▼]

Alluvial plains constitute essential geological bodies for environmental studies such as contaminated sites remediation, low-enthalpy geothermal energy or groundwater resources. The heterogeneity of these deposits governs flow processes and needs to be quantified. A proper description of such complex deposits requires an integrated approach combining geological, geophysical and hydrogeological data. Solving such spatial inverse problems in the Earth Sciences remains a considerable challenge given the large number of parameters to invert for, the non-linearity of forward models and, as a result, the ill-posedness of the problem. Geostatistics is therefore needed to specify prior models, more particularly, information to control the spatial features of the inverse solutions. Two-point geostatistical approaches have been developed to describe the heterogeneity of one geological formation but fail to reproduce the heterogeneity of fluvial deposits with multiple facies. Multiple-point statistics (MPS) introduced the training image (TI) concept to replace the variogram within an extended sequential simulation framework. The use of geophysics to constrain such simulations has been studied in the petroleum industry with wave-based methods (seismic reflection), but little research has been done to assess the use of near-surface potential methods to condition MPS in environmental studies. In this work, we propose to integrate geological (borehole logs), geophysical (electrical resistivity tomography (ERT) profiles) and hydrogeological (hydraulic heads) data within MPS models on the alluvial plain of the Meuse River, Belgium. Potential-based geophysical methods being integrative, they suffer from a relatively poor resolution. We first study how we can improve the informative content of geophysical inversion by including prior information in the ERT inverse problem. Three methods are tested and compared in several field cases, namely the reference model inversion, the structural inversion and the regularized geostatistical inversion. If every method has advantages and drawbacks, the best suited method for the considered problem is the regularized geostatistical method. Electromagnetic borehole logs enable to derive the vertical correlation length of electrical resistivity in the deposits and to subsequently use it to constrain the inversion. In addition to the knowledge of the bedrock position, it enables to retrieve an electrical resistivity distribution of the deposits close to direct observations. This ensures that geophysical models will be informative to constrain MPS simulations. Given the lack of geological and sedimentological data to build accurate TIs, a data base of TIs is built using several different parameters and scenarios. They are all based on a three facies description: clay/loam, sand and gravel corresponding to low, intermediate and high hydraulic conductivity. Then, we develop a methodology to verify the consistency of independently-built TIs with geophysical data. Our methodology starts by creating subsurface models with each TI. From these models we create synthetic geophysical data and from this synthetic data, synthetic inverted models. These models are now compared with a single inverted model obtained from the field survey, allowing for our definition of what is ``consistent''. To that extent, we calculate the Euclidean distance between any two inverted models as well as field data and visualize the results in a 2D or 3D space using multidimensional scaling (MDS). With this technique, it is possible to verify if field cases fall in the distribution represented by synthetic cases, and thus are consistent with them. In a second step, we present a cluster analysis on the MDS-map to highlight which parameters are the most sensitive for the construction of TI. Based on this analysis, a probability of each geological scenario is computed through kernel smoothing of the densities in reduced projected metric space. The integration of hydrogeological data is made through a stochastic inversion method: the probability perturbation method (PPM), using MPS constrained with geophysical data to generate models. The PPM algorithm automatically seeks solutions fitting both hydrogeological data and training-image based geostatistical constraints. Only geometrical features of the model are affected by the perturbation, i.e. we do not attempt to directly find the optimal value of hydrogeological parameters (chosen a priori), but the optimal spatial distribution of facies whose prior distribution is quantified in a training image. Tracing experiments may be used to further constrain hydrogeological models. ERT has proven its ability to monitor salt tracer tests, but few studies have investigated its performances in thermal tracing experiments. In this study, we demonstrate the ability of surface and crosshole ERT to image quantitatively temperature changes during heat injection experiments. Such resistivity data provides important information to improve hydrogeological models. Our study proves that ERT, especially crosshole ERT, is a reliable tool to follow thermal tracing experiments. It also confirms that ERT should be included to in situ techniques to characterize heat transfer in the subsurface and to monitor geothermal resources exploitation. [less ▲]

Detailed reference viewed: 200 (68 ULiège)
Full Text
See detailIntegration of near-surface geophysical, geological and hydrogeological data with multiple-point geostatistics in alluvial aquifers
Hermans, Thomas ULiege; Nguyen, Frédéric ULiege

Scientific conference (2011, October 20)

This work takes place in the context of the following PhD research topic. Alluvial plains constitute essential geological bodies for environmental studies such contaminated sites remediation, low-enthalpy ... [more ▼]

This work takes place in the context of the following PhD research topic. Alluvial plains constitute essential geological bodies for environmental studies such contaminated sites remediation, low-enthalpy geothermal energy or groundwater resources. The general objective of this work is to contribute to a better quantification of the heterogeneity of the parameters governing flow and transport processes by combining near-surface geophysics and geostatistics. Two-points geostatistical approaches (variogram based) have been developed to quantify the heterogeneity of one geological formation but fail to reproduce the heterogeneity of fluvial deposits with multiple facies. Multiple-points geostatistics introduced the training image concept to replace the variogram within an extended sequential simulation framework. The role of the training image is to depict the conceptual geological patterns. Previous studies have demonstrated the need for more conditioning data to generate an efficient training image. The use of geophysics in this context has been studied in the petroleum research with wave-based methods (seismic reflection data). However, little research has been done to assess the use of near-surface geophysical measurements, relying on potential and wave methods, to condition multiple-point geostatistics for environmental studies. This research project will focus on three specific objectives. The first will consist in computing conceptual training images from the combination of near-surface geophysics images, geological information and borehole data. The second objective will use these images to build models of the subsurface properties with multiple-point geostatistics conditioned to site-specific near-surface geophysical data and borehole information. Finally, groundwater model parameter estimation will be performed using a geologically consistent perturbation approach based on tracer experiments, using well sampling and time-lapse geophysical data. The approach will be demonstrated on both synthetic benchmarks and real field sites. This presentation shows preliminary research results on the use of combined geophysical techniques to improve geophysical models, the building of geological scenarios (training images) in the Meuse alluvial aquifer and the use of time-lapse ERT data to improve our understanding of hydrogeological reservoirs. [less ▲]

Detailed reference viewed: 42 (7 ULiège)
Full Text
Peer Reviewed
See detailIntegration of order picking and vehicle routing in a B2C e-commerce context
Moons, Stef; Ramaekers, Katrien; Caris, An et al

in Flexible Services and Manufacturing Journal (2017)

E-commerce sales are increasing every year and customers who buy goods on the Internet have high service level expectations. In order to meet these expectations, a company’s logistics operations need to ... [more ▼]

E-commerce sales are increasing every year and customers who buy goods on the Internet have high service level expectations. In order to meet these expectations, a company’s logistics operations need to be performed carefully. Optimizing only internal warehouse processes will often lead to suboptimal solutions. The interrelationship between the order picking process and the delivery process should not be ignored. Therefore, in this study, an order picking problem and a vehicle routing problem with time windows and release dates are solved simultaneously using a single optimization framework. To the best of our knowledge, it is the first time that an order picking problem and a vehicle routing problem are integrated. A mixed integer linear programming formulation for this integrated order picking-vehicle routing problem (OP-VRP) is provided. The integrated OPVRP is solved for small instances and the results are compared to these of an uncoordinated approach. Computational experiments show that integration can lead to cost savings of 14% on average. Furthermore, higher service levels can be offered by allowing customers to request their orders later and still get delivered within the same time windows. [less ▲]

Detailed reference viewed: 35 (7 ULiège)
Full Text
Peer Reviewed
See detailIntegration of photovoltaic cells in solar drying systems
Bennamoun, Lyes ULiege

in Drying Technology (2013), 31(11), 1284-1296

Detailed reference viewed: 48 (3 ULiège)
Full Text
See detailIntegration of Photovoltaic Panels Into Low-voltage Distribution Networks
Olivier, Frédéric ULiege

Master's dissertation (2013)

We address in this thesis the problem of overvoltages caused by photovoltaic (PV) panels in low-voltage networks. As a solution to this problem, we propose new active network management schemes. They work ... [more ▼]

We address in this thesis the problem of overvoltages caused by photovoltaic (PV) panels in low-voltage networks. As a solution to this problem, we propose new active network management schemes. They work by modulating in an ad-hoc way the power injected by the PV inverters into the low-voltage network. Two types of control schemes are studied: centralized ones and distributed ones. The centralized schemes compute the modulation orders by exploiting an optimal power flow formulation of the problem. The distributed schemes are based on simple control logics implemented in the inverters and using only local information. Henceforth, they are less expensive to build than centralized ones. Both types of schemes are tested on a simple test network. The simulation results show that they are indeed able to control the voltages so that they stay within their limits. Moreover, the distributed schemes are shown to perform almost as well as the centralized ones, when using as performance metric the amount of energy curtailed on the PV installations. [less ▲]

Detailed reference viewed: 97 (19 ULiège)
See detailIntegration of quality indices of distribution in benchmarking analysis
Coelli, Tim; Gautier, Axel ULiege; Perelman, Sergio ULiege et al

Report (2011)

Detailed reference viewed: 22 (7 ULiège)
See detailIntegration of quality indices of distribution in benchmarking analysis
Coelli, Tim; Gautier, Axel ULiege; Perelman, Sergio ULiege et al

Report (2011)

Detailed reference viewed: 14 (1 ULiège)
Full Text
Peer Reviewed
See detailIntegration of recrystallisation model coupled with an elasto-visco-plastic law - Experimental tests and calibration of this model
Charles, J. F.; Habraken, Anne ULiege; Lecomte-Beckers, Jacqueline ULiege

in Proceedings of the 2nd ESAFORM Conference on Material Forming (1999)

The recrystallisation model is based on the model developed by Kopp [1,2]. This model is implemented in our finite element code "lagamine" and is coupled with a thermomechanical elasto-visco-plastic law ... [more ▼]

The recrystallisation model is based on the model developed by Kopp [1,2]. This model is implemented in our finite element code "lagamine" and is coupled with a thermomechanical elasto-visco-plastic law. It assumes that each integration point in the mesh is represented by a number of sub-structures with a different volumic recrystallised fraction. In order to be able to calibrate such a model, we need to perform a lot of experimentals tests. Hot compression tests on small cylinder at different temperatures and strain rates are made till strain level from 0.1 up to 0.7. The compressed cylinders are quenched after the tests. A metallographic study of the quenched cylinders gives the recrystallised fraction function of the strain, the strain rate and temperature. So experimental, numerical and metallographic studies of hot compression tests aim the definition of an accurate predictive thermo-mechanic metallurgical model able to stimulate forging processes. [less ▲]

Detailed reference viewed: 36 (2 ULiège)
Full Text
Peer Reviewed
See detailIntegration of the selective deconvolution algorithm into a multiresolution scheme
Van Droogenbroeck, Marc ULiege; Vandendorpe, Luc

in Image Processing: Algorithms and Techniques III (1992, February)

Detailed reference viewed: 54 (5 ULiège)