References of "Palm, Rodolphe"
     in
Bookmark and Share    
Full Text
See detailEfficiency of inventory plot patterns in quantitative analysis of vegetation : a case study of tropical woodland and dense forest in Benin
Salako, Valère K.; Glele Kakai, Romain L.; Assogbadjo, Achille E. et al

in Southern Forests : a Journal of Forest Science (2013), 75(3), 137-143

Detailed reference viewed: 7 (0 ULg)
Full Text
Peer Reviewed
See detailEffect of inventory plot patterns in the floristic analysis of tropical woodland and dense forest
Houeto, Georges; Glele Kakai, Romain L.; Salako, Valère et al

in African Journal of Ecology (2013), 51(3),

Detailed reference viewed: 8 (2 ULg)
Full Text
See detailCubage des arbres et des peuplements forestiers - Tables et équations
Dagnelie, Pierre; Rondeux, Jacques ULg; Palm, Rodolphe ULg

Book published by Presses agronomiques de Gembloux (2013)

Detailed reference viewed: 105 (17 ULg)
Full Text
Peer Reviewed
See detailImpact of Data Structure on the Estimators R-Square and adjusted R-Square in Linear Regression
Akossou, A. Y. J.; Palm, Rodolphe ULg

in International Journal of Mathematics and Computation (2013), 20(3), 84-93

Detailed reference viewed: 11 (0 ULg)
Full Text
See detailLa représentation d'une matrice par biplot
Palm, Rodolphe ULg; Charles, Catherine ULg; Claustriaux, Jean-Jacques ULg

in Notes de Statistique et d'Informatique (2012), (2), 1-22

Matrix factorization by means of singular value decomposition is examined and used to produce a graphical representation of a data matrix called biplot. The link between this biplot and the plots of the ... [more ▼]

Matrix factorization by means of singular value decomposition is examined and used to produce a graphical representation of a data matrix called biplot. The link between this biplot and the plots of the variables and of the individuals usually given in principal component analysis is discussed and applied to an example. [less ▲]

Detailed reference viewed: 20 (4 ULg)
Full Text
See detailTables de contingence à trois dimensions : aspects théoriques, applications et analogie avec l'analyse de la variance à trois critères de classification
Claustriaux, Jean-Jacques ULg; Palm, Rodolphe ULg; Ferrandis Vallterra, Salvador ULg et al

in Notes de Statistique et d'Informatique (2012), (1), 19

For contingency table, concepts of independence are not so easy to understand in statistical practice. So, theoretical aspects of the log-linear model are described and applied to a three levels example ... [more ▼]

For contingency table, concepts of independence are not so easy to understand in statistical practice. So, theoretical aspects of the log-linear model are described and applied to a three levels example; an analogy with analysis of variance is also established. [less ▲]

Detailed reference viewed: 53 (7 ULg)
Full Text
Peer Reviewed
See detailProgramme de Gestion Durable de l'Azote en agriculture. Considérations pratiques et conceptuelles sur la méthodologie du contrôle public du reliquat d'azote nitrique dans le sol des exploitations agricoles wallonnes
Vandenberghe, Christophe ULg; Palm, Rodolphe ULg; Lambert, Richard et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(1), 25-32

Within the Walloon Action Programme, transposition of the Nitrates Directive, the Administration organizes each year a control of the soil nitrate nitrogen residues in about 900 parcels located in ... [more ▼]

Within the Walloon Action Programme, transposition of the Nitrates Directive, the Administration organizes each year a control of the soil nitrate nitrogen residues in about 900 parcels located in vulnerable zone in order to verify if the practices of nitrogen spreading by the farmers are in accordance with the Walloon Action Programme. The current method is to yearly spot “suspects” by a control in three parcels in about 300 farms and to follow “suspects” by an observation programme wich leads after maximum six years to a penalty or to the end of this programme. The present statistical study means to assess the public control’s methodology: what is the probability to penalize a “good” farmer, to forget a “bad” farmer? This study is based on real data and on a theoretical approach. Both conclusions indicate that the official methodology is sufficiently appropriate. [less ▲]

Detailed reference viewed: 53 (4 ULg)
Full Text
See detailInférence statistique et critères de qualité de l'ajustement en régression logistique binaire
Palm, Rodolphe ULg; Brostaux, Yves ULg; Claustriaux, Jean-Jacques ULg

in Notes de Statistique et d'Informatique (2011), (5), 32

The principles of statistical inference based on the maximum likelihood function are described and applied to binary logistic regression. Several goodness of fit statistics are also given. These topics ... [more ▼]

The principles of statistical inference based on the maximum likelihood function are described and applied to binary logistic regression. Several goodness of fit statistics are also given. These topics are illustrated by an example processed by Minitab and SAS softwares. [less ▲]

Detailed reference viewed: 49 (4 ULg)
Full Text
See detailLa régression logistique avec Minitab
Palm, Rodolphe ULg; Brostaux, Yves ULg

in Notes de Statistique et d'Informatique (2011), (4), 15

This note describes the Minitab commands BLOGISTIC, NLOGISTIC and OLOGISTIC and proposes a macro, which can be downloaded, for coding the data in order to fit the continuation-ratio logits model. The ... [more ▼]

This note describes the Minitab commands BLOGISTIC, NLOGISTIC and OLOGISTIC and proposes a macro, which can be downloaded, for coding the data in order to fit the continuation-ratio logits model. The commands are illustrated by an example. [less ▲]

Detailed reference viewed: 49 (10 ULg)
Full Text
Peer Reviewed
See detailSimuler pour comprendre : un didacticiel pour l'apprentissage de notions de base en statistique inférentielle
Palm, Rodolphe ULg; Allagbe, Germain

in Statistique et Enseignement (2011), 2(1), 77-84

Detailed reference viewed: 6 (1 ULg)
Full Text
See detailMacros Minitab pour le choix d'une transformation pour la normalisation de variables
Palm, Rodolphe ULg; Brostaux, Yves ULg; Claustriaux, Jean-Jacques ULg

in Notes de Statistique et d'Informatique (2011), (3),

Macros are proposed to Minitab users for transforming data to normality. The following transformations are examined : log transformation, Box et Cox transformation with lambda equal to -2, -1, -0,5, 0,5 ... [more ▼]

Macros are proposed to Minitab users for transforming data to normality. The following transformations are examined : log transformation, Box et Cox transformation with lambda equal to -2, -1, -0,5, 0,5 and 2, Box et Cox transformation with maximum likelihood estimation of lambda and transformations using the Johnson system of distributions. Two examples are given. [less ▲]

Detailed reference viewed: 52 (7 ULg)
Full Text
Peer Reviewed
See detailPrincipaux modèles utilisés en régression logistique
Gillet, Adeline; Brostaux, Yves ULg; Palm, Rodolphe ULg

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2011), 15(3), 425-433

Regression is a commonly used technique for describing the relationship between a response variable and one or more explanatory variables. When the response variable is a categorical variable, usual ... [more ▼]

Regression is a commonly used technique for describing the relationship between a response variable and one or more explanatory variables. When the response variable is a categorical variable, usual regression based on ordinary least squares should be replaced by logistic regression. Binary logistic regression should be used to perform a regression on a dichotomous response. Nominal polytomous logistic regression applies to a categorical response variable that has more than two levels with a natural ordering. And ordinal polytomous logistic regression is used when the response is a categorical variable that has more than two levels with a natural ordering. This note gives an overview of these logistic regression methods and describes three models commonly used when performing ordinal logistic regression. These models are illustrated by an example related to oak decline in the Walloon Region (Belgium). [less ▲]

Detailed reference viewed: 72 (10 ULg)
Full Text
Peer Reviewed
See detailTesting coexistence of extinction debt and colonization credit in fragmented calcareous grasslands with complex historical dynamics
Piqueray, Julien ULg; Cristofoli, Sara; Bisteau, Emmanuelle et al

in Landscape Ecology (2011), 26

Calcareous grasslands are among the most species-rich ecosystems in temperate countries. However, these ecosystems have suffered from fragmentation and destruction during the last century. We studied the ... [more ▼]

Calcareous grasslands are among the most species-rich ecosystems in temperate countries. However, these ecosystems have suffered from fragmentation and destruction during the last century. We studied the response of calcareous grassland plant diversity to landscape changes in Belgium. Results indicated that high area loss (since 1965) old habitat patches exhibited an extinction debt inverse to low area loss old habitat patches, little depending on the area loss threshold (60%, 70%, 80% or 90%) considered for the distinction between the high and low area loss patches. However, human activities also created new habitat patches in the landscape and therefore provided opportunities for calcareous grassland plant species to colonize new habitats. This also provided opportunities to study species colonization abilities in the context of habitat restoration. We analyzed species richness in new patches compared to old patches in order to detect colonization credit. We detected the presence of a colonization credit in new patches when using high loss old patches (area loss>80%, exhibiting an extinction debt) or all old patches as a reference. However, when the reference was low loss old patches alone (area loss<80%, less likely to exhibit an extinction debt), no colonization credit was detected. In addition, species composition was similar between new patches and old patches. These results are encouraging for restoration programs. However, the results indicated that the presence of an extinction debt in reference habitats could lead to inaccurate conclusions in restoration monitoring. Therefore, extinction debt should be considered when choosing reference habitats to evaluate restoration success. [less ▲]

Detailed reference viewed: 55 (19 ULg)
Full Text
Peer Reviewed
See detailPlant species extinction debt in a temperate biodiversity hotspot: community, species and functional traits approaches
Piqueray, Julien ULg; Bisteau, Emmanuelle; Cristofoli, Sara et al

in Biological Conservation (2011), 144

Destruction and fragmentation of (semi-) natural habitats are considered the main causes of biodiversity loss worldwide. Plant species may exhibit a slow response to fragmentation, resulting in the ... [more ▼]

Destruction and fragmentation of (semi-) natural habitats are considered the main causes of biodiversity loss worldwide. Plant species may exhibit a slow response to fragmentation, resulting in the development of an extinction debt in fragmented plant communities. The detection of extinction debt is of primary importance in habitat conservation strategies. We applied two different approaches proposed in the literature to identify extinction debt in Southeast Belgium calcareous grasslands. The first method compared species richness between stable and fragmented habitat patches. The second explored correlations between current species richness and current and past landscape configurations using multiple regression analyses. We subsequently examined results generated by both methods. In addition, we proposed techniques to identify species that are more likely to support extinction debt and associated functional traits. We estimated a respective extinction debt of approximately 28% and 35% of the total and specialist species richness. Similar results were obtained from both methods. We identified 15 threatened specialist species under the current landscape configuration. It is likely the landscape configuration no longer supports the species habitat requirements. We demonstrated that non-clonal species are most threatened, as well as taxa that cannot persist in degraded habitats and form only sparsely distributed populations. We discussed our results in light of other studies in similar habitats, and the overall implications for habitat conservation. [less ▲]

Detailed reference viewed: 70 (7 ULg)
Full Text
Peer Reviewed
See detailA sorting optimization curve with quality and yield requirements
Ooms, David ULg; Palm, Rodolphe ULg; Leemans, Vincent ULg et al

in Pattern Recognition Letters (2010), 31(9), 983-990

Binary classifiers used for sorting can be compared and optimized using receiver-operating characteristic (ROC) curves which describe the trade-off between the false positive rate and true positive rate ... [more ▼]

Binary classifiers used for sorting can be compared and optimized using receiver-operating characteristic (ROC) curves which describe the trade-off between the false positive rate and true positive rate of the classifiers. This approach is well suited for the diagnosis of human diseases where individual costs of misclassification are of great concern. While it can be applied to the sorting of merchandise or other materials, the variables described by the ROC curve and its existing alternatives are less relevant for that range of applications and another approach is needed. In this paper, quality and yield factors are introduced into a sorting optimization curve (SOC) for the choice of the operating point of the classifier, associated with the prediction of output quantity and quality. Given examples are the sorting of seeds and apples with specific requirements. In both cases the operating point of the classifier is easily chosen on the SOC, while the output characteristics of the sorted product are accurately predicted. [less ▲]

Detailed reference viewed: 120 (30 ULg)