Search results for "Conflicting objectives"
showing 10 items of 12 documents
Analyzing Stakeholder Diversity in G2G Efforts: Combining Descriptive Stakeholder Theory and Dialectic Process Theory
2008
Author's version of an article published in e-Service Journal, 6 (2), 3-23. Previous research indicates that the benefits of e-government initiatives are slower to realize than initially expected. This has partly been ascribed to the particularly complex settings of e-government projects, consisting of a variety of stakeholders promoting different and often conflicting objectives. Yet few studies have explicitly addressed the inherent challenges of this diversity. This study presents an analytical approach for investigating contradictory stakeholder interests by combining descriptive stakeholder theory and dialectic process theory. Descriptive stakeholder theory is concerned with why some s…
INTERNAL PRESSURE AND COUNTERPUNCH ACTION DESIGN IN Y-SHAPED TUBE HYDROFORMING PROCESSES: A MULTI OBJECTIVE OPTIMISATION APPROACH
2009
In sheet metal forming most of the problems are multi-objective problems, generally characterised by conflicting objectives. A classical approach to investigate such kind of problems is focused on a combination of multiple objectives into a unique objective function to be optimised. Actually, in metal forming processes optimisation two main phases have to be developed in order to reach an optimal solution: the former is the modelling phase (definition of the design variables and objective function) and the latter concerns the computational aspect (numerical simulations or experiment to be developed). In this paper, an integration between numerical simulations, response surface methodology a…
AGV-served assembly lines: influence of sequencing and launch policies on system performances
1990
SUMMARY The planning of an AGV-based flexible assembly line is studied. The conflicting objectives of the minimization of the AGVs wait along the line and of the maximization of the system productivity are investigated. To improve the system performances the late start policy to launch and transfer the AGVs is introduced and a heuristic sequencing algorithm is proposed. The developed computer-aided planning procedures make it possible to consider different AGV launch policies, buffer capacities and management goals; moreover, with the combined use of effective sequences a better utilization of the different resources is reached.
Interactive multiobjective optimization with NIMBUS for decision making under uncertainty
2013
We propose an interactive method for decision making under uncertainty, where uncertainty is related to the lack of understanding about consequences of actions. Such situations are typical, for example, in design problems, where a decision maker has to make a decision about a design at a certain moment of time even though the actual consequences of this decision can be possibly seen only many years later. To overcome the difficulty of predicting future events when no probabilities of events are available, our method utilizes groupings of objectives or scenarios to capture different types of future events. Each scenario is modeled as a multiobjective optimization problem to represent differe…
A survey on handling computationally expensive multiobjective optimization problems using surrogates: non-nature inspired methods
2015
Computationally expensive multiobjective optimization problems arise, e.g. in many engineering applications, where several conflicting objectives are to be optimized simultaneously while satisfying constraints. In many cases, the lack of explicit mathematical formulas of the objectives and constraints may necessitate conducting computationally expensive and time-consuming experiments and/or simulations. As another challenge, these problems may have either convex or nonconvex or even disconnected Pareto frontier consisting of Pareto optimal solutions. Because of the existence of many such solutions, typically, a decision maker is required to select the most preferred one. In order to deal wi…
Experiments with classification-based scalarizing functions in interactive multiobjective optimization
2006
In multiobjective optimization methods, the multiple conflicting objectives are typically converted into a single objective optimization problem with the help of scalarizing functions and such functions may be constructed in many ways. We compare both theoretically and numerically the performance of three classification-based scalarizing functions and pay attention to how well they obey the classification information. In particular, we devote special interest to the differences the scalarizing functions have in the computational cost of guaranteeing Pareto optimality. It turns out that scalarizing functions with or without so-called augmentation terms have significant differences in this re…
Interactive Multiobjective Optimization of Superstructure SMB Processes
2009
We consider multiobjective optimization problems arising from superstructure formulation of Simulated Moving Bed (SMB) processes. SMBs are widely used in many industrial separations of chemical products and they are challenging from the optimization point of view. We employ efficient interactive multiobjec-tive optimization which enables considering several conflicting objectives simultaneously without unnecessary simplifications as have been done in previous studies. The interactive IND-NIMBUS software combined with the IPOPT optimizer is used to solve multiobjective SMB design problems. The promising results of solving a superstructure SMB optimization problem with four objectives demonst…
APROS-NIMBUS: Dynamic Process Simulator and Interactive Multiobjective Optimization in Plant Automation
2013
Abstract Virtual commissioning of chemical plants often involves a dynamic simulator and an optimization method. This paper demonstrates the integration of APROS, a dynamic process simulator and IND-NIMBUS, an interactive multiobjective optimization software. We implement a multiobjective concentration control problem in APROS involving conflicting objectives and employ a decision maker to interact with IND-NIMBUS and express his preference information to finally obtain his most preferred solution. The results of this study show that APROS and IND-NIMBUS can be integrated and an interactive multiobjective optimization method can help the decision maker in exploring trade-offs among conflict…
Branch-and-Cut-and-Price for the Vehicle Routing Problem with Time Windows and Convex Node Costs
2019
Two critical yet frequently conflicting objectives for logistics and transportation service companies are improving customer satisfaction and reducing transportation cost. In particular, given a network of customer requests with preferred service times, it is very challenging to find vehicle routes and service schedules simultaneously that respect all operating constraints and minimize the total transportation and customers’ inconvenience costs. In this paper, we introduce the vehicle routing problem with time windows and convex node costs (VRPTW-CNC), in which we model each customer’s inconvenience cost as a convex function of the service start time at that customer. The VRPTW-CNC combine…
Visualizations for Decision Support in Scenario-based Multiobjective Optimization
2021
Reproducibility artifacts for: Babooshka Shavazipour, Manuel López-Ibáñez, and Kaisa Miettinen. Visualizations for Decision Support in Scenario-based Multiobjective Optimization. Information Sciences, 2021. doi:10.1016/j.ins.2021.07.025. Abstract: We address challenges of decision problems when managers need to optimize several conflicting objectives simultaneously under uncertainty. We propose visualization tools to support the solution of such scenario-based multiobjective optimization problems. Suitable graphical visualizations are necessary to support managers in understanding, evaluating, and comparing the performances of management decisions according to all objec…