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 detailPrimo @ ULg : Implémentation de Primo 4.1 à l'ULg
Renaville, François ULg; Richelle, Laurence ULg

Conference given outside the academic context (2013)

Detailed reference viewed: 85 (24 ULg)
Full Text
See detailPrimo v.3 en test dans le Réseau des Bibliothèques ULg. Premier retour sur la phase de test
Simon, Stéphanie ULg; Mignon, Jacques ULg; Rizzo, Sandra ULg et al

Conference given outside the academic context (2011)

Detailed reference viewed: 208 (88 ULg)
See detailUn prince en faillite. Jean de Flandre, évêque de Metz (1279/80-1282), puis de Liège (1282-1291)
Marchandisse, Alain ULg

Book published by Académie royale de Belgique - Commission royale d'Histoire (1997)

Detailed reference viewed: 20 (6 ULg)
Full Text
Peer Reviewed
See detailPrincipal component analysis based on robust estimators of the covariance or correlation matrix: Influence functions and efficiencies
Croux, C.; Haesbroeck, Gentiane ULg

in Biometrika (2000), 87(3), 603-618

A robust principal component analysis can be easily performed by computing the eigenvalues and eigenvectors of a robust estimator of the covariance or correlation matrix. In this paper we derive the ... [more ▼]

A robust principal component analysis can be easily performed by computing the eigenvalues and eigenvectors of a robust estimator of the covariance or correlation matrix. In this paper we derive the influence functions and the corresponding asymptotic variances for these robust estimators of eigenvalues and eigenvectors. The behaviour of several of these estimators is investigated by a simulation study. It turns out that the theoretical results and simulations favour the use of S-estimators, since they combine a high efficiency with appealing robustness properties. [less ▲]

Detailed reference viewed: 23 (6 ULg)
Full Text
Peer Reviewed
See detailPrincipal component analysis of Piezo-Sensor Array for damage localization
De Boe, Pascal; Golinval, Jean-Claude ULg

in Structural Health Monitoring (2003), 2(2), 137-144

This paper focuses on applying statistical process control techniques, based on principal component analysis, to vibration-based damage diagnosis. It is well known that localized structural damages with ... [more ▼]

This paper focuses on applying statistical process control techniques, based on principal component analysis, to vibration-based damage diagnosis. It is well known that localized structural damages with relative small amplitude do not affect much the global modal response of the structure, at least at low frequencies. Nevertheless, it can be expected that the local dynamic behavior of a damaged structural subcomponent is significantly affected. Assuming that each structural subcomponent is monitored, local structural damage, with relative small amplitude, will only affect a particular sensor without affecting significantly the response of the others. By applying a principal component analysis on the sensor time responses, it is possible to see that any change of one particular sensor will affect the subspace spanned by the complete sensor response set. The subspace corresponding to the damaged structure can then be compared with the subspace of an initial state in order to diagnose possible damage. The principal component analysis may also be performed for every potential subset of damaged sensors in order to identify the involved sensor, and, therefore, the damaged structural component. The spatial information given by the distributed sensors (e.g. piezoelectric laminates) can be used to forecast structural damages on a critical area but damage localization is also possible with classical sensors (e.g. accelerometers). The damage may be located as the errors attain the maximum at the sensors instrumented in the damaged substructures. [less ▲]

Detailed reference viewed: 38 (2 ULg)
Full Text
Peer Reviewed
See detailPrincipal components approach for estimating heritability of mid-infrared spectrum in bovine milk
Soyeurt, Hélène ULg; Tsuruta, Shogo; Misztal, Ignacy et al

in Journal of Dairy Science (2007)

Detailed reference viewed: 16 (2 ULg)
Full Text
Peer Reviewed
See detailPrincipal disease and Insect pests of Jatropha curcas L. in the lower valley of the Senegal river
Terren, Marieke ULg; Mignon, Jacques ULg; De Clerck, Caroline ULg et al

in Tropicultura (2012), 30(4), 222-229

Jatropha curcas L. seed oil is proven to be toxic to many microorganisms, insects and animals. Despite its toxicity, Jatropha is not pest and disease resistant. The following major pests and diseases ... [more ▼]

Jatropha curcas L. seed oil is proven to be toxic to many microorganisms, insects and animals. Despite its toxicity, Jatropha is not pest and disease resistant. The following major pests and diseases affecting Jatropha in the lower valley of the Senegal river have been identified: the leaf miner Stomphastis thraustica (Meyrick, 1908) (Lepidoptera, Gracillariidae), the leaf and stem miner Pempelia morosalis (Saalmuller, 1880) (Lepidoptera, Pyralidae) and the shield-backed bug Calidea panaethiopica (Kirkaldy, 1909) (Heteroptera, Scutelleridae), which can cause flower and fruit abortion. Damage from these pests was particularly great during the second year after the plantations were set up (2009) and before later receding. Nevertheless, the worst attacks were caused by a vascular disease transmitted through the soil, which killed 65% of the plants in four years. It is mainly characterised by collar and root rot, which causes foliage to yellow and wilt, before the plant eventually dies. These threats should increase if larger areas are planted with Jatropha. Considering the scale of the damage caused by these attacks in Bokhol, the development of an integrated pest management programme adapted to the local context should be considered. [less ▲]

Detailed reference viewed: 315 (26 ULg)
Full Text
Peer Reviewed
See detailPrincipal role of glycoprotein VI in alpha2beta1 and alphaIIbbeta3 activation during collagen-induced thrombus formation.
Lecut, Christelle ULg; Schoolmeester, Anne; Kuijpers, Marijke J E et al

in Arteriosclerosis, Thrombosis, and Vascular Biology (2004), 24(9), 1727-33

OBJECTIVE: High-shear perfusion of blood over collagen results in rapid platelet adhesion, aggregation, and procoagulant activity. We studied regulation of alpha2beta1 and alphaIIbbeta3 integrin ... [more ▼]

OBJECTIVE: High-shear perfusion of blood over collagen results in rapid platelet adhesion, aggregation, and procoagulant activity. We studied regulation of alpha2beta1 and alphaIIbbeta3 integrin activation during thrombus formation on collagen. METHODS AND RESULTS: Blockade of glycoprotein (GP) VI by 9O12 antibody or of P2Y purinergic receptors permitted platelet adhesion but reduced aggregate formation, fibrinogen binding, and activation of alpha2beta1 and alphaIIbbeta3, as detected with antibodies IAC-1 and PAC1 directed against activation-dependent epitopes of these integrins. Combined blockade of GPVI and P2Y receptors and thromboxane formation abolished integrin activation but still allowed adhesion of morphologically unstimulated, nonprocoagulant platelets. Exogenous ADP partly restored the suppressive effect of GPVI blockade on integrin alpha2beta1 and alphaIIbbeta3 activation. Adhesion was fully inhibited only with simultaneous blocking of GPVI and alpha2beta1, indicating that the integrin can support platelet-collagen binding in the absence of its activation. Blockade or absence of GPIbalpha only moderately influenced integrin activation and adhesion unless GPVI was inhibited. CONCLUSIONS: GPVI- and autocrine-released ADP induce affinity changes of alpha2beta1 and alphaIIbbeta3 during thrombus formation on collagen under flow. These integrin changes are dispensable for adhesion but strengthen platelet-collagen interactions and thereby collagen-induced platelet activation. Integrin activation during thrombus formation on collagen was studied using fluorescent-labeled antibodies IAC-1 and PAC1 directed against activation-dependent epitopes of alpha2beta1 and alphaIIbbeta3 integrin, respectively. Glycoprotein VI blockade by 9O12 antibody or P2Y ADP receptors reduced integrin activation along with aggregate formation and fibrinogen binding but not alpha2beta1-dependent adhesion. [less ▲]

Detailed reference viewed: 30 (2 ULg)
Full Text
Peer Reviewed
See detailPrincipal static wind loads
Blaise, Nicolas ULg; Denoël, Vincent ULg

in 6th Proceedings of European-African Conference on Wind Engineering (2013, July 07)

The concept of static wind load is widely used in practice for structural wind design. In this context, this paper assesses the envelope reconstruction problem stated as follows: find the best set of ... [more ▼]

The concept of static wind load is widely used in practice for structural wind design. In this context, this paper assesses the envelope reconstruction problem stated as follows: find the best set of static loadings that is optimum to reproduce by static analyses, the envelope values of structural responses resulting from a formal buffeting dynamic analysis. A solution was recently derived by means of Principal Static Wind Loads which are well-suited for this problem. The concept is illustrated with a large stadium roof and the accuracy of the envelope reconstruction is analysed. [less ▲]

Detailed reference viewed: 54 (13 ULg)
Full Text
Peer Reviewed
See detailPrincipal static wind loads
Blaise, Nicolas ULg; Denoël, Vincent ULg

in Journal of Wind Engineering & Industrial Aerodynamics (2013), 113

In current wind design practice, static wind loads are usually defined to obtain, by simple static analyses, the extreme values of any structural response that would be formally obtained with a strict ... [more ▼]

In current wind design practice, static wind loads are usually defined to obtain, by simple static analyses, the extreme values of any structural response that would be formally obtained with a strict dynamic buffeting analysis. The minimum and maximum values that may reach any response define the envelope. Equivalent static wind loads (ESWLs) allow to recover extreme responses in the envelope. As a first objective, this paper formalizes a general method to determine ESWL, in a nodal basis, by extending the concept of load-response correlation, which is only valid in the background range. The general method, the displacement-response-correlation (DRC) method, covers the background and resonant contributions of the considered response. As a second objective, the paper addresses the problem of building a set of static wind loads that adequately reconstructs the envelopes of responses. The concept of principal static wind loads (PSWL) is introduced to form a reduced basis of representative loads well-suited for envelope reconstruction. Its optimality is demonstrated both analytically and with a detailed illustrative example. [less ▲]

Detailed reference viewed: 77 (20 ULg)
Full Text
Peer Reviewed
See detailPrincipal Static Wind Loads on a large roof structure
Blaise, Nicolas ULg; Hamra, Lotfi ULg; Denoël, Vincent ULg

in Proceedings of the 12th ANIV conference of wind engineering In Vento (2012, October 07)

Usually, structural wind design is realized using static wind loads. Such loadings are expected, as a main property, to recover by static analyses, the envelope values that would be obtained by a formal ... [more ▼]

Usually, structural wind design is realized using static wind loads. Such loadings are expected, as a main property, to recover by static analyses, the envelope values that would be obtained by a formal buffeting analysis. For simple structures, equivalent static wind loads might be used but they are established in order to reproduce envelope values of specific structural responses and are thus not suitable to reconstruct efficiently the entire envelope. Recently, more general methods were derived to propose global static loadings that reconstruct the entire envelope but several drawbacks remained as their robust applicability for any structure and accuracy. This paper addresses a new type of static loadings, the principal static wind loads, derived in a strict mathematical way, the singular value decomposition, to make it optimum for the envelope reconstruction problem. The method is illustrated with a large roof and the reconstruction accuracy is analysed by studying the rate of envelope reconstruction, envelope previously obtained by a rigourous stochastic analysis. The way principal loadings are derived makes them suitable for combinations in order to increase the rate of the envelope reconstruction. As a major outcome, the method provides a finite number of design load cases that matches a desired level of accuracy in the envelope reconstruction. [less ▲]

Detailed reference viewed: 189 (92 ULg)
Full Text
Peer Reviewed
See detailA Principal-Agent Theory Approach to Public Expenditure Management Systems in Developing Countries
Leruth, Luc ULg; Paul, Elisabeth ULg

in OECD Journal on Budgeting (2007), 7(3),

A well-functioning public expenditure management system (PEM) is considered a critical pillar of government efficiency. This article discusses PEM systems in developing countries using an analytical ... [more ▼]

A well-functioning public expenditure management system (PEM) is considered a critical pillar of government efficiency. This article discusses PEM systems in developing countries using an analytical framework based on principal-agent theory. This simple model can be applied to various PEM systems and allows for comparisons between institutional settings. To illustrate this, the authors analyse the benefits derived from the use by the ministry of finance of ex post audits and ex ante controls, and assess their value in terms of their ability to deter cheating. The authors derive a set of possible “control regimes” which can be used by the ministry of finance. [less ▲]

Detailed reference viewed: 64 (3 ULg)
Full Text
Peer Reviewed
See detailA Principal-Agent Theory Approach to Public Expenditure Management Systems in Developing Countries
Leruth, Luc ULg; Paul, Elisabeth ULg

in IMF Working Paper (2006), 06/204

A well-functioning public expenditure management (PEM) system is considered a critical pillar of government efficiency, on par with a low-distortion tax system and efficient tax administration. The paper ... [more ▼]

A well-functioning public expenditure management (PEM) system is considered a critical pillar of government efficiency, on par with a low-distortion tax system and efficient tax administration. The paper discusses PEM systems in developing countries using an analytical framework based on principal-agent theory. This simple model can be applied to various PEM systems, and allows for comparisons between institutional settings. To illustrate this, we analyze the benefits derived from the use by the Ministry of Finance (MoF) of two control instruments; ex post audits and ex ante controls, and assess their value in terms of their ability to deter cheating. We derive a set of possible “control regimes” which can be used by the MoF. Although we illustrate the use of the model using developing countries, it is also relevant to developed economies. [less ▲]

Detailed reference viewed: 37 (4 ULg)
See detailLes principales causes de mortalité des jeunes bovins en race Bleu Blanc
Lomba, Fernand; Lekeux, Pierre ULg

in Vlaams Diergeneeskundig Tijdschrift (1984), 53

Detailed reference viewed: 31 (2 ULg)
See detailLes principales formations végétales
Ouédraogo, M.; Vermeulen, Cédric ULg; Cornélis, D.

in Delvingt, W.; Vermeulen, Cédric (Eds.) Nazinga (2007)

Detailed reference viewed: 11 (1 ULg)