Pour savoir comment effectuer et gérer un dépôt de document, consultez le « Guide abrégé – Dépôt de documents » sur le site Web de la Bibliothèque. Pour toute question, écrivez à corpus@ulaval.ca.
 

Personne :
Azouzi, Riadh.

En cours de chargement...
Photo de profil

Adresse électronique

Date de naissance

Projets de recherche

Structures organisationnelles

Fonction

Nom de famille

Azouzi

Prénom

Riadh.

Affiliation

Département de génie mécanique, Faculté des sciences et de génie, Université Laval

ISNI

ORCID

Identifiant Canadiana

person.page.name

Résultats de recherche

Voici les éléments 1 - 4 sur 4
  • PublicationAccès libre
    A strategic forest management model for optimizing timber yield and carbon sequestration
    (Society of American Foresters, 2020-12-01) Rönnqvist, Mikael; Carle, Marc-André; D'Amours, Sophie; Azouzi, Riadh.
    Strategic forest management planning models designed to maintain existing carbon stocks and maximize capacity for future sequestration can help identify underused opportunities to increase carbon stocks without diminishing other forest products. This study proposed a carbon stock unit that allows summing up the stocks in the different forest pools even if the decomposition far exceeds the planning horizon. This unit is used to integrate the methods and algorithms from the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) model into a wood supply model. The resulting model could be used to predict changes in carbon stocks, transfers between carbon pools, and greenhouse gas emissions that would result from every forest management activity. We tailored this model to meet different strategies: maximizing carbon storage in the forest, maximizing high-sustained timber yield, and achieving the dual objectives of yield and carbon storage. A range of management scenarios were simulated using the data of a 485,000 hectares mixed-wood forest in Quebec, Canada. Our results demonstrate that, with the reduction in the harvest rates, the increase in the ecosystem carbon storage is insufficient to offset the carbon losses associated with the increase in the harvest rates. Study Implications: In this article, we adopt the perspective of forest managers who contend that removing lumber from the forest can be achieved in a responsible way or in a way that does not affect the carbon stocks in the forest in the long term. We propose a model that integrates methods and algorithms from the CBM-CFS3 model to simulate carbon dynamics of aboveground and belowground biomass and dead organic matter, including soils. The model can be used to predict carbon storage potential within a forest region assuming a given management strategy. We used data of a large forest area to develop a number of sophisticated scenarios of strategic forest planning. Our results are consistent with the forest managers’ contentions. When carbon was maximized regardless of volume, the increase in the ecosystem carbon storage was insufficient to offset the carbon losses associated with the reduction in the harvest rates.
  • PublicationAccès libre
    Timber selling policies using bundle-based auction : the case of public forests in Québec
    (Elsevier, 2018-08-20) Rönnqvist, Mikael; Carle, Marc-André; D'Amours, Sophie; Azouzi, Riadh.
    In the province of Québec, the government provides 25% of the volume of timber that is annually cut in crown forests through sealed-bid one-winner auctions. It was noted that many offers are made for some areas but few or none are made for many other areas. As such, a significant number of the timber volumes remains unsold. However, the combination of areas to form bundles can provide economy of scale that is not seen otherwise. We highlight some issues regarding the current allocation system and we analyse the effectiveness of different bundling systems in maximizing government revenues and enhancing bidders' competitiveness. We use actual forest data to evaluate different rules and strategies for the creation and allocation of partial and full bundles. Our results suggest that the use of the option of bundling forests areas makes the auction process more beneficial to the majority of stakeholders: Government revenues are increased; the bidding companies are more likely to obtain the desired volumes and pay less for harvesting and equipment relocation; and greenhouse gas emissions are reduced.
  • PublicationAccès libre
    The online wood supply game
    (INFORMS, 2017-07-24) Marier, Philippe; Rönnqvist, Mikael; D'Amours, Sophie; Azouzi, Riadh.; Fjeld, Dag
    This paper describes the Wood Supply Game (WSG), a prize-winning e-learning tool that is freely available for players all over the world. The game effectively helps students and managers realize the challenges in managing demand and supply in wood supply chains, and gain insight into the types of measures required to make these divergent chains effective. The WSG is an adaptation of the Beer game, a popular didactic tool used to empirically demonstrate demand amplification in a simple and generic context. The supply chain modeled by the Beer game does not involve co-products, and thus is very different from the wood supply chain, which is divergent by nature. The WSG presented in this paper models a supply network with one point of divergence and demand for two products. This preserves the simplicity of the game but enables it to offer a base for supply network simulation in a large number of industrial sectors with divergent processes. We describe an online version of the WSG, discuss our experiences playing it with students and managers, and provide hints to the instructor.
  • PublicationAccès libre
    Integrated optimization of strategic and tactical planning decisions in forestry
    (Elsevier, 2016-11-12) Bouchard, Mathieu; Rönnqvist, Mikael; D'Amours, Sophie; Azouzi, Riadh.; Gunn, Eldon A.
    The traditional approach to plan the forest products value chain using a combination of sequential and hierarchical planning phases leads to suboptimal solutions. We present an integrated planning model to support forest planning on the long term with anticipation of the impacts on the economic and logistic activities in the forest value chain on a shorter term, and we propose a novel optimization approach that includes acceleration strategies to efficiently solve large-scale practical instances of this integrated planning problem. Our model extends and binds the models implemented in two solver engines that have developed in previous work. The first system, called Logilab, allows for defining and solving value chain optimization problems. The second system, called Silvilab, allows for generating and solving strategic problems. We revisit the tactical model in Logilab and we extend the strategic model in Silvilab so that the integrated planning problem can be solved using column generation decomposition with the subproblems formulated as hypergraphs and solved using a dynamic programing algorithm. Also, a new set of spatial sustainability constraints is considered in this model. Based on numerical experiments on large-scale industrial cases, the integrated approach resulted in up to 13% profit increase in comparison with the non-integrated approach. In addition, the proposed approach compares advantageously with a standard LP column generation approach to the integrated forest planning problem, both in CPU time (with an average 2.4 factor speed-up) and in memory requirement (with an average reduction by a factor of 20).