Takehiro Inohara

Strategic analysis of the Kyoto Protocol

Systems methodologies for analyzing independent behavior and coalition formation under conflict are employed to examine the strategic impact of the decision of the United States not to sign the Kyoto Protocol upon the preferences and attitudes of Russia. The reduction of greenhouse gases to control climate change is a complex system of systems problem involving not only environmental factors but also social, economic and political issues among industrial and developing nations. The Kyoto Protocol of 1997 was an attempt to provide economic and political incentives for nations to join a coalition for the reduction of emission levels. The analysis of this conflict demonstrates the influence that the United States had on the Kyoto Protocol and the effects of international relationships in forming a working coalition to combat climate change.

On conditions for a meeting not to reach a deadlock

A formal model for describing the interaction stage in a meeting, particularly, persuasion and compromise by the members in a meeting, is proposed. Using the model, a sufficient condition for a meeting not to reach a deadlock is provided. The condition implies that stable emotion of members of a meeting is essential for the meeting not to reach a deadlock.

Attitudes and preferences: Approaches to representing decision maker desires

Abstract Informative interrelationships between attitudes and preferences when formally studying a conflict within the framework of the Graph Model for Conflict Resolution are specified through the development of formal theorems. Specifically, the parallel nature of attitudes and preferences is illuminated to show how attitudes can provide a simple way to more effectively represent complex preference structures when decision makers hold concern for other decision makers’ interests. To illustrate this important property of attitudes, the Graph Model for Conflict Resolution is applied to the negotiation over the sale of a brownfield property both with and without attitudes.

A method to compare influence of coalitions on group decision other than desirability relation

Abstract This paper proposes a method to compare influence of coalitions on group decision, called blockability relation. This relation is defined both on the set of all coalitions and on the set of all feasible coalitions. Examples show that this relation is definitely different from the desirability relation, which have been dealt with in the literature. In particular, an example shows that the desirability relation is not always transitive, and a proposition verifies that the blockability relation is always transitive. In order to clarify the simple games on which these relations are defined and to investigate interrelationships among these simple games, three types of operators, called L-intersection, L-restriction and extension, respectively, on simple games are defined, where L is a family of all feasible coalitions. It is verified that the extension of the L-intersection of a simple game coincides with the restriction of the simple game.

Characterization of clusterability of signed graph in terms of Newcomb's balance of sentiments

Clusterability of a signed graph is characterized with a concept of stability of sentiments given by Newcomb in social psychology. Compared to an existing characterization, the characterization given in this paper is more useful to interpret the clustering of a group of persons in the real world as a psychological phenomenon.

A characterization of completeness of blockability relations with respect to unanimity

This paper gives a characterization of completeness of blockability relations on simple games. It is verified in this paper that the blockability relation on a simple game is complete if and only if the simple game is S-unanimous for some coalition S in N.

Propositions on interrelationships among attitude-based stability concepts

This paper provides some propositions on interrelationships among attitude-based stability concepts within the graph model for conflict resolution. Concentrating on the cases in which just two decision makers having specific types of attitudes are involved, the authors investigate various interrelationships among such attitude-based stability concepts as relational Nash stability, relational general metarationality, relational symmetric metarationality, and relational sequential stability. In particular, it is verified that under the condition that all of the attitudes of the decision makers are the same, relational Nash stability and relational sequential stability are equivalent to each other.

Clusterability of groups and information exchange in group decision making with approval voting system

In this paper, we discuss the relations between clusterability of a group and information exchange in a situation of decision making of the group. Based on the equivalence of clusterability to Newcombs stability of sentiments, we show that the concept of interaction consistency of a group that is involved in a decision making situation of selecting a set of representatives of the group from the members of the group, the concept that is newly proposed in this paper, is equivalent to the clusterability of the group. Moreover, we propose the concept of quasi-clusterability of a group, the concept that is a generalization of the concept of clusterability of a group, and show that the interaction consistency of a group that is involved in a decision making situation of selecting a set of representatives of the group from a set of candidates, each of which is a member of the group, is equivalent to the quasi-clusterability of the group.

Methods for comparison of coalition influence on games in characteristic function form and their interrelationships

Abstract This paper extends two existent methods, called the blockability relation and the viability relation, for simple games to compare influence of coalitions, to those for games in characteristic function form, and shows that the newly defined relations satisfy transitivity and completeness. It is shown in this paper that for every game in characteristic function form the blockability relation and the viability relation have a complementary interrelationship.

Comparability of coalitions in committees with permission of voters by using desirability relation and hopefulness relation

In this paper, we treat committees with permission of voters, and examine comparability of the effectiveness and the efficiency of coalitions in a committee by using formal ways, that is, the desirability relation and the hopefulness relation. Consequently, we obtain a necessary and sufficient condition for desirability relation of the permission game of a committee with permission of voters to be complete, that is, the desirability relation is complete if and only if there is no pair of coalitions whose supporters are mutually different. Moreover, we give an example of committees in which there are coalitions whose effectiveness and efficiency cannot be compared.