Vladimir Bushenkov - Profile on Academia.edu (original) (raw)

Papers by Vladimir Bushenkov

Forest Science, 2019

This research addresses the problem of forested landscape management planning in contexts charact... more This research addresses the problem of forested landscape management planning in contexts characterized by multiple ecosystem services and multiple stakeholders. A new methodology for participatory landscape-level forest management is proposed. Specifically, a bilevel representation is used, whereas models of subsystems are used for constructing an integrated model of the master problem. Participatory workshops and interactive visualization of the Pareto frontier are used to support the solution of the multi-objective optimization upper- and lower-level problems. The visualization is implemented by a technique—Interactive Decision Maps—that displays interactively the Pareto frontier in the form of decision maps, that is, collections of the objectives’ tradeoff curves. Since the upper-level problem may be characterized by a large number of decision variables, we compare the Pareto frontier generated by the Interactive Decision Maps technique with the Pareto frontier generated by a de...

Optimization Methods & Software, 1992

An iteration method of constructing orthogonal projections of convex polyhedral sets

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

For the monolayer adsorption on a homogeneous surface, including arbitrary range lateral interact... more For the monolayer adsorption on a homogeneous surface, including arbitrary range lateral interactions, the isotherm can be written as a power series of the Langmuir isotherm. If this isotherm is used as the kernel in the adsorption integral equation, this integral equation can be solved in an analytical form. Because the global isotherm is usually known as a set of experimental values, the use of a numerical method is inevitable. A new numerical method for solving the adsorption integral equation with a kernel of general form is developed. It is based on recent results concerning the structure of the local isotherm and on the ideas of complex approximation with constraints, and allows reduction of the problem under consideration to a linear-quadratic programming problem. Results of numerical experiments are presented. The method can be useful for the evaluation of the adsorption energy distribution from experimental data.

Regulation under conditions of uncertainty

Computational Mathematics and Mathematical Physics, Feb 1, 1992

Journal of Computational Chemistry, Jul 30, 2001

Constraint Modeling for Forest Management

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...

Multi‐criteria supply chain network design using interactive decision maps

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

In this work we analyze an optimal control problem for a system of two hydroelectric power statio... more In this work we analyze an optimal control problem for a system of two hydroelectric power stations in cascade with reversible turbines. The objective is to optimize the profit of power production while respecting the system's restrictions. Some of these restrictions translate into state constraints and the cost function is nonconvex. This increases the complexity of the optimal control problem. The problem is solved numerically and two different approaches are adopted. These approaches focus on global optimization techniques (Chen-Burer algorithm) and on a projection estimation refinement method (PER method). PER method is used as a technique to reduce the dimension of the problem. Results and execution time of the two procedures are compared.

Journal of Quantitative Economics, 2016

Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch ge... more Die Dokumente auf EconStor dürfen zu eigenen wissenschaftlichen Zwecken und zum Privatgebrauch gespeichert und kopiert werden. Sie dürfen die Dokumente nicht für öffentliche oder kommerzielle Zwecke vervielfältigen, öffentlich ausstellen, öffentlich zugänglich machen, vertreiben oder anderweitig nutzen. Sofern die Verfasser die Dokumente unter Open-Content-Lizenzen (insbesondere CC-Lizenzen) zur Verfügung gestellt haben sollten, gelten abweichend von diesen Nutzungsbedingungen die in der dort genannten Lizenz gewährten Nutzungsrechte. Terms of use: Documents in EconStor may be saved and copied for your personal and scholarly purposes. You are not to copy documents for public or commercial purposes, to exhibit the documents publicly, to make them publicly available on the internet, or to distribute or otherwise use the documents in public. If the documents have been made available under an Open Content Licence (especially Creative Commons Licences), you may exercise further usage rights as specified in the indicated licence.

An algorithm for approximating the Pareto frontier in multiobjective integer programming problems

Forests, 2014

Cork oak (Quercus suber L.) and holm oak (Quercus rotundifolia) ecosystems are characteristic of ... more Cork oak (Quercus suber L.) and holm oak (Quercus rotundifolia) ecosystems are characteristic of Mediterranean forestry in Portugal. Even though cork is the most valuable product, these ecosystems provide multiple products and services. Assessing trade-offs between multiple goals is thus critical for the effectiveness of oak ecosystem management planning. This paper focuses on the development of a decision support system for oak ecosystems' scenario analysis including multiple criteria. It includes an innovative decision support systems (DSS) functionality to assess trade-offs between the criteria that may support negotiation and consensus building between decision-makers and forest stakeholders. Specifically, a module that encapsulates the Feasible Goals Method/Interactive Decision Maps (FGM/IDM) technique is developed for interactive visualization of the Pareto frontier. The Pareto frontier illustrates the degree to which improving one particular criterion requires accepting sacrifices in the achievements of others. It thus provides information about trade-offs between competing decision-makers' preferences. Results are discussed for a large-scale application encompassing over 1 million ha of cork and holm oak forest ecosystems in Southern Portugal. This study demonstrates the potential of the new

Water Resource Conflict Resolution Based on Interactive Tradeoffs Display

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.

In this paper we consider a simplified model for a system of hydroelectric power stations with re... more In this paper we consider a simplified model for a system of hydroelectric power stations with reversible turbines. The objective of our work is to obtain the optimal profit of power production satisfying restrictions on the water level in the reservoirs. Two different numerical approaches are applied and compared. These approaches center on global optimization techniques (Chen-Burer algorithm) and on Projection Estimation Refinement method (PER method) used to reduce the dimension of the problem.

Forest Systems, 2013

Aim of study: In this paper, we present a decision support system (DSS) to support decision makin... more Aim of study: In this paper, we present a decision support system (DSS) to support decision making where different stakeholders have to generate landscape and forest level strategic plans. We further present an interactive approach that may take advantage of a posteriori preference modelling (i.e. Pareto frontier technique) to facilitate the specification of the levels of achievement of various objectives. Area of study: The approach was applied to one planning cycle of a real world study case, the Leiria National Forest in Portugal. The Leiria National Forest, a managed area of approximately eleven thousand hectares in which 8,679 hectares are even aged stands of maritime pine (Pinus pinaster Ait) aimed at the production of wood. Material and methods: The interactive approach, at first, tries to generate Pareto efficient frontiers for different objectives. Then, multiple decision makers are involved in the process to seek an agreement towards the definition of a consensual strategic plan. Main results: The system developed in this article integrates an information management subsystem, a module to generate alternative management regimes, growth model routines and a decision module that generates and solves mathematical formulations. It also provides a module to display reports and view the resulting solutions (management plans). We also build the Pareto frontier for different criteria. The results show that the proposed DSS can help solve strategic planning problems subject to sustainable management constraints where people organize themselves and participate jointly to manage their natural resources. Research highlights: The interactive approach facilitates the involvement of multiple stakeholders in the decision making process.

Optimization Methods and Software, 1992