Vladimir Bushenkov | Universidade de Évora (original) (raw)

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Papers by Vladimir Bushenkov

Optimization Methods & Software, 1992

U.S.S.R. computational mathematics and mathematical physics, 1985

ABSTRACT A numerical method of constructing bounded projections of convex polyhedral sets, specif... more ABSTRACT A numerical method of constructing bounded projections of convex polyhedral sets, specified using finite sets of linear inequalities in a subspace of small dimensions is proposed.

Journal of Computational Chemistry, Feb 1, 2000

Computational Mathematics and Mathematical Physics, Feb 1, 1992

Journal of Computational Chemistry, Jul 30, 2001

Springer proceedings in mathematics & statistics, 2022

Forests

The conversion of fertile croplands to Eucalyptus woodlots in Ethiopian highlands, due to its bus... more The conversion of fertile croplands to Eucalyptus woodlots in Ethiopian highlands, due to its business attractiveness to smallholders, raises concerns related to food production, water resources, carbon and other ecosystem services. This study was therefore designed to examine land allocation and plantation management decisions. Our emphasis was on the analysis of tradeoffs between the economic gains obtained from harvesting Eucalyptus timber and food production, carbon and water use. For that purpose, we considered a 1987 ha agroforest landscape in the Amhara region, Northern Ethiopia. With a planning horizon covering nine one-year periods, we developed and used nine Model I single objective linear programming (LP) models, and analyzed tradeoffs between objectives (e.g., land expectation value (LEV), Carbon, volume of ending inventory (VolEI), crop production and water use) using an LP-based Pareto frontier approach. The study revealed that the objective of maximizing the total eco...

Journal of Multi-Criteria Decision Analysis, 2021

Growing concerns about sustainability lead decision‐makers to include in the supply chain network... more Growing concerns about sustainability lead decision‐makers to include in the supply chain network design, environmental and social impacts as well as economic objectives, which requires a balanced multi‐criteria approach. In this paper, a multi‐objective mixed integer model for a regional supply chain network of a fish processing industry is developed. The model and decision‐making process is analysed using approximation and visualization of Pareto frontier in criteria space in the form of Interactive Decision Maps. For test purposes, the data of the network of tilapia fillet processing in West Paraná, Brazil, are used. A reasonable strategy is formulated, representing a compromise between different conflicting criteria in the supply chain — profit, carbon dioxide emissions, number of suppliers, number of hired workers, costs and revenue.

Forests, 2021

Decision making in modern forest management planning is challenged by the need to recognize multi... more Decision making in modern forest management planning is challenged by the need to recognize multiple ecosystem services and to address the preferences and goals of stakeholders. This research presents an innovative a posteriori preference modeling and multi-objective integer optimization (MOIP) approach encompassing integer programming models and a new technique for generation and interactive visualization of the Pareto frontier. Due to the complexity and size of our management problems, a decomposition approach was used to build the Pareto frontier of the general problem using the Pareto frontiers of its sub-problems. The emphasis was on the approximation of convex Edgeworth–Pareto hulls (EPHs) for the sub-problems by systems of linear inequalities; the generation of Edgeworth–Pareto hulls by the convex approximation of the Pareto frontier evinced a very small discrepancy from the real integer programming solutions. The results thus highlight the possibility of generating the Paret...

Information, 2020

This research expands the applicability of the Feasible Goals (FGoal) Pareto frontier multiple cr... more This research expands the applicability of the Feasible Goals (FGoal) Pareto frontier multiple criteria method to display the Edgeworth–Pareto hull using interactive decision maps (IDMs). Emphasis is placed upon the development of a communication architecture to display the Pareto frontiers, which includes a client device, a web server, and a dedicated computation server implemented with sockets. A standalone application on the latter processes client-server requests and responses to display updated information on the client. Specifically, the dedicated computation server is responsible for calculating the information needed to generate the Edgeworth–Pareto hull. This is delivered to the web server to generate the IDM to be displayed on the client device. The key innovation of this work is a tool that is developed to aid decision-makers with a network-based computational architecture that includes a computational server constantly in communication with a web server for fast response...

Forests, 2019

In this paper, we present a web-based decision support system (DSS)—wSADfLOR—to facilitate the ac... more In this paper, we present a web-based decision support system (DSS)—wSADfLOR—to facilitate the access of stakeholders to tools that may contribute to enhancing forest management planning. The emphasis is on a web-based architecture and a web graphic user interface (wGUI) that may effectively support the analysis of trade-offs between ecosystem services in order to address participatory and sustainable forest management objectives. For that purpose, the wGUI provides remote access to a management information system, enabling users to analyze environmental and biometric data and topological information as well. Moreover, the wGUI provides remote access to forest simulators so that users may define and simulate prescriptions such as chronological sequences of management options and the corresponding forest ecosystem services outcomes. Remote access to management planning methods is further provided so that users may input their objectives and constraints. The wGUI delivers information ...

Applied Mathematics & Information Sciences, 2016

Journal of Quantitative Economics, 2016

Rehabilitation of degraded water resource systems, especially large scale systems such as Danube,... more Rehabilitation of degraded water resource systems, especially large scale systems such as Danube, Mississippi or the Volga River, inevitably involve conflicts over who pays, who benefits, and how much. This paper reviews the application of computer-aided approaches to water resources conflict resolution based on the generation and interactive display of the efficient tradeoff curves among conflicting performance criteria associated with various possible decisions. Computing of efficient tradeoffs is based on a mathematical model describing the system being managed. The model is supposed to be mutually acceptable to all stakeholders. Negotiators can interactively explore the full implications of solutions that represent efficient tradeoffs among identified performance criteria. In this way they can become more informed about compromises that can be made among conflicting criteria. This approach is applied to the real-time allocation of water to agricultural and environmental users whose demand for water usually exceeds the supply. Application of these procedures using computer networks (e.g., Internet or intranets) is discussed.