1,721,421 research outputs found
A comparative study of game theoretic and evolutionary models for software agents
No full textMost of the existing work in the study of bargaining behaviour uses techniques from game theory. Game theoretic models for bargaining assume that players are perfectly rational and that this rationality in common knowledge. However, the perfect rationality assumption does not hold for real-life bargaining scenarios with humans as players, since results from experimental economics show that humans find their way to the best strategy through trial and error, and not typically by means of rational deliberation. Such players are said to be boundedly rational. In playing a game against an opponent with bounded rationality, the most effective strategy of a player is not the equilibrium strategy but the one that is the best reply to the opponent's strategy. The evolutionary model provides a means for studying the bargaining behaviour of boundedly rational players. This paper provides a comprehensive comparison of the game theoretic and evolutionary approaches to bargaining by examining their assumptions, goals, and limitations. We then study the implications of these differences from the perspective of the software agent developer
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Comparing equilibria for game theoretic and evolutionary bargaining models
No full textGame-theoretic models of bargaining are typically based on the assumption that players have perfect rationality and that they always play an equilibrium strategy. In contrast research research in experimental economics shows that in bargaining between human subjects, participants do not always play the equilibrium strategy. Such agents are said to be boundedly rational. In playing a game against a boundedly rational opponent, a player's most effective strategy is not the equilibrium strategy, but the one that is the best reply to the opponent's actual strategy. Against this background, this paper studies the bargaining behaviour of boundedly rational agents byusing genetic algorithms. Since bargaining involves players with different utility functions, we have two subpopulations - one represents the buyer, and the other represents the seller (i.e., the population is asymmetric). We study the competitive co-evolution of strategies in the two subpopulations for an incomplete information setting, and compare the results with those prescribed by game theory. Our analysis leads to two main conclusions. Firstly, our study shows that although each agent in the game-theoretic model has a strategy that is dominant at every period at which it makes a move, the stable state of the evolutionary model does not always match the game-theoretic equilibrium outcome. secondly, as the players mutually adapt to each other's strategy, the stable outcome depends on the initial population
An agenda based framework for multi-issues negotiation
No full textThis paper presents a new model for multi-issue negotiation under time constraints in an incomplete information setting. The issues to be bargained over can be associated with a single good/service or multiple goods/services. In our agenda-based model, the order in which issues are bargained over and agreements are reached is determined endogenously, as part of the bargaining equilibrium. In this context we determine the conditions under which agents have similar preferences over the implementation scheme and the conditions under which they have conflicting preferences. Our analysis shows the existence of equilibrium even when both players have uncertain information about each other, and each agent’s information is its private knowledge. We also study the properties of the equilibrium solution and determine conditions under which it is unique, symmetric, and Pareto-optimal
Optimal negotiation of multiple issues in incomplete information settings
No full textThis paper studies bilateral multi-issue negotiation between self-interested agents. The outcome of such encounters depends on two key factors: the agenda (i.e., the set of issues under negotiation) and the negotiation procedure (i.e., whether the issues are discussed together or separately). Against this background, this paper analyses such negotiations by varying the agenda and negotiation procedure. This analysis is carried out in an incomplete information setting in which an agent knows its own negotiation parameters, but has incomplete information about its opponent’s. We first determine the equilibrium strategies for two negotiation procedures: issue-by-issue and package deal. On the basis of these strategies we determine the negotiation outcome for all possible agenda–procedure combinations and the optimal agenda–procedure combination for each agent. We determine those conditions for which agents have identical preferences over the optimal agenda and procedure and those for which they do not, and for both conditions we show the optimal agenda and procedure
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