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See detailLayering of Size and Type Noun Constructions in English
Brems, Lieselotte ULg

Book published by Mouton de Gruyter - 1st (2011)

On the basis of synchronic and diachronic data analysis, the volume takes a close look at the synchronic layers of binominal size noun and type noun uses (a bunch/a load of X; a sort of X; a Y type of X ... [more ▼]

On the basis of synchronic and diachronic data analysis, the volume takes a close look at the synchronic layers of binominal size noun and type noun uses (a bunch/a load of X; a sort of X; a Y type of X) and reconsiders the framework of grammaticalization in view of issues raised by the phrases under discussion. As a result, a construction grammar-approach to grammaticalization is developed which does justice to the syntagmatic lexical, or collocational, reclustering observed in the data within an eclectic cognitive-functional approach. Prices subject to change. Shipping costs will be added. Current pricing is based [less ▲]

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See detailLayout Optimization : A Mathematical Programming Approach
Duysinx, Pierre ULg

Report (1997)

This paper presents applications of specially tailored methods of the mathematical programming approach for solving topology design problems formulated as an optimal material distribution, providing a way ... [more ▼]

This paper presents applications of specially tailored methods of the mathematical programming approach for solving topology design problems formulated as an optimal material distribution, providing a way to enlarge the scope of potential applications of topology optimization. The first feature of the methodology is to resort to dual maximization to solve optimization problems with a huge number of design variables, using the concept of Sequential Convex Programming (SCP). Here a central theme is the choice of convex approximations suited to the problems. First order approximations are firstly considered and compared. However, to increase the performances of the procedures (for example, to reduce the number of steps to arrive to a stationary design), a new approach to build un-expensive second approximation schemes, especially relevant for large scale problems, have been developed and validated. To illustrate the efficiency of the mathematical programming approach, the final part of the paper deals with an efficient treatment of perimeter constraints. Such constraints are essential to regularize material distribution with non optimal microstructures, but perimeter constraints are very difficult to handle in a numerical procedure for practical designs. The paper presents a solution to this problem that has been implemented and validated on a wide range of applications. [less ▲]

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See detailLayout Optimization : A Mathematical Programming Approach
Duysinx, Pierre ULg

Conference (1996, August)

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See detailLazy planning under uncertainty by optimizing decisions on an ensemble of incomplete disturbance trees
Defourny, Boris ULg; Ernst, Damien ULg; Wehenkel, Louis ULg

in Defourny, Boris; Ernst, Damien; Wehenkel, Louis (Eds.) Recent Advances in Reinforcement Learning (2008)

This paper addresses the problem of solving discrete-time optimal sequential decision making problems having a disturbance space W composed of a finite number of elements. In this context, the problem of ... [more ▼]

This paper addresses the problem of solving discrete-time optimal sequential decision making problems having a disturbance space W composed of a finite number of elements. In this context, the problem of finding from an initial state x0 an optimal decision strategy can be stated as an optimization problem which aims at finding an optimal combination of decisions attached to the nodes of a disturbance tree modeling all possible sequences of disturbances w0, w1, . . ., w(T−1) in W^T over the optimization horizon T. A significant drawback of this approach is that the resulting optimization problem has a search space which is the Cartesian product of O(|W|^(T−1)) decision spaces U, which makes the approach computationally impractical as soon as the optimization horizon grows, even if W has just a handful of elements. To circumvent this difficulty, we propose to exploit an ensemble of randomly generated incomplete disturbance trees of controlled complexity, to solve their induced optimization problems in parallel, and to combine their predictions at time t = 0 to obtain a (near-)optimal first-stage decision. Because this approach postpones the determination of the decisions for subsequent stages until additional information about the realization of the uncertain process becomes available, we call it lazy. Simulations carried out on a robot corridor navigation problem show that even for small incomplete trees, this approach can lead to near-optimal decisions. [less ▲]

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See detailLazy sensors for the scheduling of measurement samples transmission in linear closed loops over networks
Forni, Fulvio ULg; Galeani, Sergio; Nesic, Dragan et al

in 49th IEEE Conference on Decision and Control (cdc 2010) (2010)

We consider an exponentially stable close-loop interconnection of a continuous linear plant and a continuous linear controller, and we study the problem of interconnecting the plant output to the ... [more ▼]

We consider an exponentially stable close-loop interconnection of a continuous linear plant and a continuous linear controller, and we study the problem of interconnecting the plant output to the controller input through a network. We propose a family of "lazy sensors" whose goal is to transmit the measured plant output information as little as possible while preserving closed-loop stability. In particular, we propose three transmission policies, providing conditions on the transmission parameters. These guarantee global asymptotic stability when the plant state is available, and global practical stability when the plant state is not available. Simulation results confirm the effectiveness of the proposed strategies. [less ▲]

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See detailLBG-SQUARE - Fault Tolerant, Locality-Aware Co-allocation in P2P Grids
Dethier, Gérard ULg; Briquet, Cyril ULg; Marchot, Pierre ULg et al

in Huang, Zhiyi; Xu, Zhiwei; Rountree, Nathan (Eds.) et al Ninth International Conference On Parallel And Distributed Computing, Applications And Technologies : PDCAT 2008 (2008, December)

In this paper, the deployment and execution of Iterative Stencil applications on a P2P Grid middleware are investigated. So-called Iterative Stencil applications are composed of sets of heavily ... [more ▼]

In this paper, the deployment and execution of Iterative Stencil applications on a P2P Grid middleware are investigated. So-called Iterative Stencil applications are composed of sets of heavily-communicating, long-running Tasks. They thus require co-allocation of multiple reliable resources for extended periods of time. P2P Grids are totally decentralized and provide on-demand, transparent access to edge resources, e.g. Internet-connected, non-dedicated desktop computers. A P2P Grid has the potential to provide access to a large number of resources at the fraction of the cost of a dedicated cluster. However, edge resources are heterogeneous in performance and intrinsically unreliable: Task execution failures are common due to resource preemption or resource failure. Furthermore, P2P Grid schedulers usually target sets of independent computational Tasks, i.e. so-called Bags of Tasks applications. It is therefore not trivial to deploy and run an Iterative Stencil application on a P2P Grid. Checkpointing is a common fault-tolerance mechanism in High Performance Distributed Computing, often based on a centralized architecture. Locality-aware co-allocation in P2P Grids has been recently investigated. Checkpointing and locality-aware co-allocation yet have to be integrated in P2P Grids. We propose to provide co-allocation through an existing middleware-level Bag of Tasks scheduling mechanism. We also introduce a layer of fault-tolerance for the Iterative Stencils that relies on a scalable, application-level, P2P checkpointing mechanism. Finally, LBG-SQUARE is described. This software results from the combination of a specific Iterative Stencil application (a Computational Fluid Dynamics simulation software called LaBoGrid) with a P2P Grid middleware (Lightweight Bartering Grid). [less ▲]

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See detailLBR-5, a Ship Hull Optimization Tool
Rigo, Philippe ULg; Hage, André ULg

in SIMOUEST’2000, European Conference, Marine Technology (2000, November)

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See detailLC determination of oxprenolol enantiomers in human plasma using dialysis as on-line sample preparation technique
Ceccato, Attilio ULg; Toussaint, B.; Chiap, Patrice ULg et al

in Journal de Pharmacie de Belgique (1996), 51

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See detailLC method for the determination of R-timolol in S-timolol maleate: Validation of its ability to quantify and uncertainty assessment.
Marini Djang'Eing'A, Roland ULg; Chiap, Patrice ULg; Boulanger, Bruno ULg et al

in Talanta (2006), 68(4), 1166-1175

This article presents the validation results of a chiral liquid chromatographic (LC) method previously developed for the quantitative determination of R-timolol in S-timolol maleate samples. A novel ... [more ▼]

This article presents the validation results of a chiral liquid chromatographic (LC) method previously developed for the quantitative determination of R-timolol in S-timolol maleate samples. A novel validation strategy based on the accuracy profiles was used to select the most appropriate regression model, to assess the method accuracy within well defined acceptance limits and to determine the limits of quantitation as well as the concentration range. The validation phase was completed by the investigation of the risk profiles of various acceptable regression models in order to ensure the risk of obtaining the future measurements outside the acceptance limits fixed a priori. On the other hand, the present paper also shows how data used in this validation approach can be used to estimate the measurement uncertainty. The uncertainty derived from beta-expectation tolerance interval (sigma(Tol)(2)), which is equal to the uncertainty of measurements as well as the expanded uncertainty (U(x)) using a coverage factor k=2 was estimated. The uncertainty estimates obtained from validation data were finally compared with those obtained from interlaboratory and robustness studies. [less ▲]

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See detailLC method for the simultaneous determination of R-timolol and other closely related impurities in S-timolol maleate: Optimization by use of an experimental design
Marini Djang'Eing'A, Roland ULg; Chiap, Patrice ULg; Boulanger, Bruno ULg et al

in Journal of Separation Science (2003), 26(9-10), 809-817

A liquid chromatography (LC) method using cellulose tris(3,5-dimethylphenylcarbamate) (5 mum) as chiral stationary phase (CSP) and a mixture of hexane, 2-propanol, and diethylamine as mobile phase was ... [more ▼]

A liquid chromatography (LC) method using cellulose tris(3,5-dimethylphenylcarbamate) (5 mum) as chiral stationary phase (CSP) and a mixture of hexane, 2-propanol, and diethylamine as mobile phase was developed for the simultaneous determination of R-timolol and other potential related substances in S-timolol maleate samples. An experimental design was elaborated in order to test the effects of the different selected factors. Three factors were studied simultaneously, namely the concentrations of 2-propanol and diethylamine as well as the column temperature. The effects of these factors were evaluated statistically. Optimal LC conditions were then deduced by applying a multicriteria decision making approach, namely Derringer's desirability function, for the responses of interest. The developed LC method was compared to the European Pharmacopoeia method and was applied to the determination of R-timolol and other related substances in several samples of S-timolol maleate from different sources. [less ▲]

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See detailLC-MS/MS multi-analyte method for mycotoxin determination in food supplements
Di Mavungu, Jose Diana; Monbaliu, Sofie; Scippo, Marie-Louise ULg et al

in Food Additives & Contaminants (2009), 26(6), 885-895

A multi-analyte method for the liquid chromatography-tandem mass spectrometric determination of mycotoxins in food supplements is presented. The analytes included A and B trichothecenes (nivalenol ... [more ▼]

A multi-analyte method for the liquid chromatography-tandem mass spectrometric determination of mycotoxins in food supplements is presented. The analytes included A and B trichothecenes (nivalenol, deoxynivalenol, 3-acetyldeoxynivalenol, 15-acetyldeoxyvalenol, neosolaniol, fusarenon-X, diacetoxyscirpenol, HT-2 toxin and T-2 toxin), aflatoxins (aflatoxin-B-1, aflaxoin-G(1) and aflatoxin-G(2)). Alternaria toxins (alternariol, alternariol methyl ether and altenuene), fumonisins (fumonisin-B-1, fumonisin-B-2 and fumonisin-B-3), ochratoxin A, zearalenone, beauvericin and sterigmatocystin. Optimization of the stimulataneous extraction of these toxins and the sample pretreatment procedure, as well as method validation were performed on maca (Lepidium meyenii) food supplements. The results indicated that the solvent mixture ethyl acetate/formic acid (95:5, v/v) n-hexane was applied as partial clean-up step to remove excess of co-extracted non-polar components. Further clean-up was performed on Oasis HLB(TM) cartidges. Samples were analysed using an Acquity UPLC system coupled to a Micromass Quattro Micro triple quadrupole mass spectrometer equipped with an electrospray interface operated in the positive-ion mode. Limits of detection and quantification were in the range of 0.3-30 ng g(-1) and 1-100 ng g(-1), respectively. Recovery yields were above 60% for most of the analytes, except for different food supplements such as soy (Glycine max) isoflavones, St John's wort (Hypericum perforatum), garlic (Allium sativum), Ginkgo biloba, and black radish (Raphanus niger) demonstrated the general applicability of the method. Due to different matrix effects observed in different food supplement samples, the standard addition approach was applied to perform correct quantitative analysis. In 56 out of 62 samples analysed, none of the 23 mycotoxins investigated was detected. Positive samples contained at least one of the toxins fumonisin-B-1, fumonisin-B-2, fumonisin-B-3 and ochratoxin A. [less ▲]

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See detailLC-SPE-NMR-MS analysis of Strychnos usambarensis fruits from Rwanda
Cao, Martine ULg; Tits, Monique ULg; Muganga, Raymond et al

in Planta Medica (2010, September), 76(12), 1241-1242

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See detailLC/MS/NMR analysis of isomeric divanilloylquinic acids from the root bark of Fagara zanthoxyloides Lam
Ouattara, Badiore; Angenot, Luc ULg; Guissou, Pierre et al

in Phytochemistry (2004), 65(8), 1145-1151

Gradient HPLC coupled to DAD/UV, MS/MS and NMR has been applied to the rapid structure determination of three new isomeric divanilloylquinic acids from Fagara zanthoxyloides collected in Burkina Faso: 3,4 ... [more ▼]

Gradient HPLC coupled to DAD/UV, MS/MS and NMR has been applied to the rapid structure determination of three new isomeric divanilloylquinic acids from Fagara zanthoxyloides collected in Burkina Faso: 3,4-O-divanilloylquinic acid, 3,5-O-divanilloylquinic acid and 4,5-O-divanilloylquinic acid. Furthermore these new compounds named burkinabins A-C could play a useful role in sickle cell disease, as the active agents of Fagara zanthoxyloides are said to be unidentified aromatic compounds with carboxylic acid grouping (Adesanya, S.A., Sofowora, A., 1983. Biological standardisation of Zanthoxylum roots for antisickling activity. Planta Med. 48, 27-33). (C) 2004 Elsevier Ltd. All rights reserved. [less ▲]

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