References of "de Wolf, Daniel"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailCrisis management: Lessons learnt from BP Deepwater Horizon Spill Oil
de Wolf, Daniel ULg

in Business Management and Strategy (2013), 4(1), 69-90

Detailed reference viewed: 11 (0 ULg)
Full Text
Peer Reviewed
See detailDesign and dimensioning of hydrogen transmission pipeline networks
de Wolf, Daniel ULg

in European Journal of Operational Research (2013), 229(1), 239-251

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailCrisis communication failures: The BP Case Study
de Wolf, Daniel ULg

in International Journal of Advances in Management and Economics (2013), 2(2), 48-56

Detailed reference viewed: 32 (0 ULg)
Full Text
Peer Reviewed
See detailSélection du portefeuille de projets d'exploration production en utilisant la méthode de Markowitz
BELAID, Fateh; de Wolf, Daniel ULg

Conference (2009, February 10)

Deux caractéristiques importantes de l’investissement en exploration ou production pétrolière sont les montants financiers très importants en jeu et les incertitudes élevées. Pour ces raisons, l’analyse ... [more ▼]

Deux caractéristiques importantes de l’investissement en exploration ou production pétrolière sont les montants financiers très importants en jeu et les incertitudes élevées. Pour ces raisons, l’analyse du risque devrait être mise en oeuvre dans le processus d’évaluation et de sélection des projets. En fonction de leurs ressources disponibles, les compagnies pétrolières sélectionnent un ensemble de projets sur la base de certains critères : la valeur actuelle nette, le taux de rendement interne, l’indice de profitabilité, etc . . . Cependant, ces critères se révèlent insuffisants vu, d’une part, l’absence de la notion du risque qui est un élément essentiel de l’industrie pétrolière, et d’autre part, l’omission des interactions entre les différents projets. Dans ce travail, afin de pallier aux insuffisances de l’approche traditionnelle, nous appliquons une variante de la méthode de Markowitz afin de déterminer le portefeuille optimal de projets d’exploration ou production qui assure le meilleur compromis risque minimum-rendement maximun sous les diverses contraintes auxquelles l’entreprise est confrontée. Un cas pratique d’application de cette méthode à la sélection de projets d’exploitation pétrolière en Mer du Nord est présenté. Ce cas pratique permet d’illustrer l’influence du facteur prix du brut sur le choix du portefeuille. [less ▲]

Detailed reference viewed: 223 (6 ULg)
Full Text
Peer Reviewed
See detailEvaluation de projets d’investissement en utilisant la simulation de Monte Carlo
BELAID, Fateh; de Wolf, Daniel ULg

Conference (2009, February 10)

L’exploration et le développement d’un champ pétrolier font face à de nom- breuses incertitudes liées aux rendements et aux coûts tout au long du cycle de vie du pro jet. A titre d’exemple les ... [more ▼]

L’exploration et le développement d’un champ pétrolier font face à de nom- breuses incertitudes liées aux rendements et aux coûts tout au long du cycle de vie du pro jet. A titre d’exemple les réserves, les investissements, les coûts opératoires, la production et le prix du pétrole sont souvent incertains. En conséquence, Il difficile de prévoir les cash-flows même pour les pro jets pétroliers les plus simples. Différentes méthodes sont disponibles pour aider les décideurs à évaluer les incertitudes, et réduire le risque des opportunités d’investissement en amont pétrolier. La simulation a été reconnue comme un outil d’analyse de risque et de prise de décision en évaluation de pro jets d’investissement en amont pétrolier au début des années 60. Aujourd’hui pra- tiquement toutes les grandes compagnies pétrolières ont incorporé la simulation dans leurs études de pro jets. Dans cet article, nous essayons d’expliquer les critères d’évalua- tion et d’analyse du risque de pro jets d’investissement en amont pétrolier basés sur les cash-flows et de montrer comment la simulation de Monte Carlo peut être utile dans ce cadre. [less ▲]

Detailed reference viewed: 196 (11 ULg)
Full Text
See detailUsing OR techniques for projets selection in the petrol industy
BELAID, Fateh; de Wolf, Daniel ULg

Conference (2009, February 05)

Two important characteristics of petroleum exploration and production investment are the high nancial amounts and uncertainties. For these rea- sons, the risk analysis should be implemented in the ... [more ▼]

Two important characteristics of petroleum exploration and production investment are the high nancial amounts and uncertainties. For these rea- sons, the risk analysis should be implemented in the projects evaluation and the selection process. Depending on their available resources, petroleum companies choose a number of projects on the basis of some criteria: the net present value, internal rate of return, pro tability index However, these criteria appear to be insu cient if we consider, on the one hand, the ab- sence of risk idea which is an essential element of the petroleum industry, on the other hand the omission of the correlations and interactions between di erent projects. In this paper, in order to make up for the lacks of the traditional approach, we apply a variant of Markowitzs method to deter- mine the e cient portfolio exploration and production projects that insure the best compromise minimum risk-maximum return under the di erent constraints faced by the company. A practical application of this method about selection of petroleum exploration projects in the North Sea is pre- sented. This practical case illustrates the in uence of the crude price in the choice of the portfolio. [less ▲]

Detailed reference viewed: 37 (4 ULg)
Full Text
See detailOptimal Design and Dimensioning of Hydrogen Transmission Distribution Pipeline Networks
Andre, Jean; BRAC, Jean; de Wolf, Daniel ULg et al

Conference (2009, February 05)

This work considers the problem of the optimal design of an hydrogen transmission network. This design problem includes the topology determi- nation and the dimensioning problem. We define a solution ... [more ▼]

This work considers the problem of the optimal design of an hydrogen transmission network. This design problem includes the topology determi- nation and the dimensioning problem. We define a solution method that simultaneously looks for the least cost topology of the network and for the optimal diameter of each pipe. These two problems were generally solved separately these last years. The application to the case of development of future hydrogen pipeline networks in France has been conducted on several urban areas. [less ▲]

Detailed reference viewed: 82 (9 ULg)
See detailEcoTransHy, Rapport final de conclusions
Andre, Jean; Brac, Jean; de Wolf, Daniel ULg et al

Report (2008)

Detailed reference viewed: 63 (9 ULg)
See detailLeast-Cost Development of Hydrogen Transmission-Distribution Pipeline Networks
Andre, Jean; Brac, Jean; de Wolf, Daniel ULg et al

Conference (2008, June)

Detailed reference viewed: 42 (7 ULg)
See detailOptimisation couplée topologie/dimensionnement de réseaux de canalisations
Andre, Jean; Brac, Jean; de Wolf, Daniel ULg et al

Conference (2008, May)

Detailed reference viewed: 84 (5 ULg)
Full Text
Peer Reviewed
See detailSolving the gas transmission problem with consideration of the compressors
Bakhouya, Bouchra; de Wolf, Daniel ULg

Conference (2008, February 25)

In [7], De Wolf and Smeers consider the problem of the gas distribution through a network of pipelines. The problem was formulated as a cost minimization subject to nonlinear flow-pressure relations ... [more ▼]

In [7], De Wolf and Smeers consider the problem of the gas distribution through a network of pipelines. The problem was formulated as a cost minimization subject to nonlinear flow-pressure relations, material balances and pressure bounds. This model does not reflect any more the current situation on the gas market. Today, the transportation and gas buying functions are separated. This work considers the new situation for the transportation company. The objective for the transportation company is to determine the flows in the network that minimize the energy used for the gas transport. This corresponds to the minimization of the power used in the compressors. [less ▲]

Detailed reference viewed: 73 (2 ULg)
Full Text
See detailEvaluation of traffic polluting gases emissions using OR techniques: the case of the city of Tunis
Guirat, Noomen; de Wolf, Daniel ULg

Conference (2008, January)

The purpose of this paper is to show how the operations research techniques can help to evaluate the emissions of polluting gases from road traffic in urban area. Our practical study case is the center of ... [more ▼]

The purpose of this paper is to show how the operations research techniques can help to evaluate the emissions of polluting gases from road traffic in urban area. Our practical study case is the center of Tunis city. To evaluate the emissions of several polluting gases (CO, CO2, SO2, NOx, CH4 and VOC), we have combined the traffic assignment model ATESAME [1] with new module implementing the CORINAIR [2] formulas. The traffic assignment model corresponds to a static User Equilibrium model that can be computed by solving a nonlinear optimization problem (See Sheffi [5]). This nonlinear convex model can be efficiently solved by using the classical Frank Wolfe technique. The CORINAIR formulas give an expression of the unitary emissions, i.e. the emissions per kilometer, as a function of the vehicle speed and of the current temperature. Several scenarios of traffic congestion and emperature conditions have been simulated for the center of Tunis City. We present here the mains results from the simulations for the center of Tunis city. [less ▲]

Detailed reference viewed: 74 (6 ULg)
Full Text
See detailOptimal dimensioning of pipe networks: the new situation when the distribution and the transportation functions are disconnected
Bakhouya, Bouchra; de Wolf, Daniel ULg

Conference (2008, January)

In [9], De Wolf and Smeers consider the problem of the optimal dimensioning of a gas transmission network when the topology of the network is known. The pipe diameters must been chosen to minimize the sum ... [more ▼]

In [9], De Wolf and Smeers consider the problem of the optimal dimensioning of a gas transmission network when the topology of the network is known. The pipe diameters must been chosen to minimize the sum of the investment and operating costs. This two stage prob- lem was solved by application of the bundle method for nonsmooth optimization. This model does not re ect any more the current situation on the gas industry. Today, the transportation function and gas buying func- tion are separated. This work considers the new situation for the trans- portation company. The objective for the transportation company is to determine the ows in the network that minimize the energy used for the gas transport. This corresponds to the minimization of the power used in the compressors. We introduce in the investment problem new decision variables, namely the maximal power of the compressor. We present here rst results obtained on the belgian gas network and on a realistic network corresponding to a part of the french network. [less ▲]

Detailed reference viewed: 49 (4 ULg)