Harri Ehtamo

Searching for joint gains in multi-party negotiations

We develop a constructive approach to multi-party negotiations over continuous issues. The method is intended to be used as a mediator’s tool for step-by-step creation of joint gains in order to reach a Pareto-optimal agreement. During the mediation process, the parties are only required to answer relatively simple questions concerning their preferences; they do not have to reveal their utility functions completely. The method generates jointly improving directions to move along, and it is a non-trivial generalization of the recently proposed two-party methods. We give a mathematical analysis together with a numerical example, but also a practical basis for negotiation support in realworld settings. ” 2001 Elsevier Science B.V. All rights reserved.

Evaluating a Framework for Multi-Stakeholder Decision Support in Water Resources Management

In this paper we describe a framework for multicriteria modeling and support of multi-stakeholder decision processes. We report on its testing in the development of a new water level management policy for a regulated lake-river system in Finland. In the framework the stakeholders are involved in the decision process from the problem structuring stage to the group consensus seeking stage followed by a stage of seeking public acceptance for the policy. The framework aims at creating an evolutionary learning process. In this paper we also focus on the use of a new interactive method for finding and identifying Pareto-optimal alternatives. Role playing experiments with students are used to test the practical applicability of a negotiation support procedure called the method of improving directions. We also describe the preference programming approach for the aggregation of the stakeholder opinions in the final evaluation of alternatives and consensus seeking.

A cooperative incentive equilibrium for a resource management problem

Abstract A two-country dynamic game model of whaling is considered. It is assumed that the countries have exact information, possibly with some time delay, about each others whaling efforts measured by the number of vessels involved in whaling. It is shown how to construct equilibrium strategies which are affine in the available information and which, when jointly carried out, realize a given Pareto-optimal decision. Numerical results suggest that some of these strategies are credible; i.e., the countries do believe that the announced strategies will be followed.

How to select fair improving directions in a negotiation model over continuous issues

Empirical evidence suggests that, in practice, it is difficult to reach Pareto-optimal agreements in negotiations. In this paper, we take a constructive approach to this question in two-party negotiations over continuous issues. A new negotiation procedure is presented that results in Pareto-optimal agreements under fairly general assumptions. The procedure uses a mediator who assists the decision makers (DMs) by choosing jointly beneficial compromises. The procedure has the appealing feature that the DMs are only required to answer relatively simple questions and their individual utility functions need not be identified completely. Moreover, the DMs reveal minimal private information to the mediator. These are properties that we would hope to have in practical procedures to be incorporated in operational negotiation support systems.

Interactive Multiple-Criteria Methods for Reaching Pareto Optimal Agreements in Negotiations

The common features of two interactive methods that can be used in multiple-party negotiations over continuous issues are studied. One method is based on finding jointly improving directions to the parties to move along and the other on making constraint proposals to the parties. The history and the related literature on the subject is briefly surveyed in order to position the methods within the field. The basic similarities and differences together with the possibility to use them jointly are studied from the point of view of single negotiation text concept. Potential application areas including facilitation agents in distributed artificial intelligence are suggested.

Incentive strategies and equilibria for dynamic games with delayed information

The construction of time-lag incentive strategies for continuous time convex problems is considered. The strategies are affine in the data available and they are represented by means of Stieltjes measures. It is shown how incentive strategies can be used as equilibrium strategies in symmetric games where the decision makers are cooperative.

On applied nonlinear and bilevel programming for pursuit-evasion games

Motivated by the benefits of discretization in optimal control problems, we consider the possibility of discretizing pursuit-evasion games. Two approaches are introduced. In the first approach, the solution of the necessary conditions of the continuous-time game is decomposed into ordinary optimal control problems that can be solved using discretization and nonlinear programming techniques. In the second approach, the game is discretized and transformed into a bilevel programming problem, which is solved using a first-order feasible direction method. Although the starting points of the approaches are different, they lead in practice to the same solution algorithm. We demonstrate the usability of the discretization by solving some open-loop representations of feedback solutions for a complex pursuit-evasion game between a realistically modeled aircraft and a missile, with terminal time as the payoff. The solutions are compared with those obtained via an indirect method.

Optimal control of double-deck elevator group using genetic algorithm

We shall introduce the principles of optimal routing of double-deck elevators. The elevator routing problem is formulated as an integer programming problem and it is solved using a genetic algorithm in a real-time system. The optimal routes of double-deck elevators have not been considered earlier in the literature. The simulation results are analyzed with discussion about the significance of the method.

FDS+Evac: An Agent Based Fire Evacuation Model

In this paper, an evacuation simulation method is presented, which is embedded in a CFD based fire modelling programme. The evacuation programme allows the modelling of high crowd density situations and the interaction between evacuation simulations and state-of-the-art fire simulations. The evacuation process is modelled as a quasi-2D system, where autonomous agents simulating the escaping humans are moving according to equations of motion and decision making processes. The space and time, where the agents are moving, is taken to be continuous, but the building geometry is discretized using fine meshes. The model follows each agent individually and each agent has its own personal properties, like mass, walking velocity, familiar doors, etc. The fire and evacuation calculations interact via the smoke and gas concentrations. A reaction function model is used to select the exit routes. The model is compared to other evacuation simulation models using some test simulations.

Dynamic cooperative electricity exchange in a power pool

An approach to the design of the transaction agreement in an electric power pool is proposed. The electricity exchange takes place over a fixed time interval in a stochastic environment. The incentive for the electricity exchanges is a disparity in the time patterns of the marginal operating costs between the utilities. Electricity produced at the different periods is used as the medium of exchange and no monetary payment between the utilities takes place. The exchange policy is chosen so that the savings are distributed to the participants in an equitable manner. The contract definition problem is approached from the point of view of cooperative game theory. Because of the inherent uncertainty, the contract is adjusted at each period so that fair division of the cost saving can be obtained.<<ETX>>