1,720,968 research outputs found
Software: Probabilistic Negotiation Framework
No full textIl software è uno dei prodotti finali del Progetto di Ricerca: Studio e sviluppo di Metodi e Modelli per la Negoziazione Elettronica, Dipartimento di Matematica per le Scienze Economiche e Sociali.
Sulla base dei risultati ottenuti nella ricerca, implementa un framework completo per la negoziazione che non permette comportamenti di natura manipolativa e collusiva delle parti
An independence concept under plausibility function
No full textStarting from considering different definitions of con- ditioning for decomposable measures, in particular for totaly monotone measures (belief functions) and to- Taly alternating measures (plausibility functions), we provide a concept of independence which covers some natural properties. In particular, we characterize the proposed independence for plausibility functions and we check some relevant properties. Relationships with other notions studied in literature are shown. Copyright © 2007 by SIPTA
Software: An enhanced expert system for fund raising management
No full textIl software migliora l'approccio del prodotto:
Luca Barzanti Mauro Gaspari Giuseppe Profiti Marcello Mastroleo. (2010). Software: An Expert System for Fund Raising Management,
utilizzando sia metodologie di:
L. Barzanti, S. Giove. (2011). Software: A decision support system for fund raising management for small- and medium-sized organizations,
sia una migliore analisi del profilo del donatore, oltre ad un approccio basato sull'impiego della funzione di utilità in luogo del modello di valore atteso
Software: Automated Negotiating Agent
No full textNell'ambito della negoziazione elettronica, ed in particolare per quanto attiene il metodo IDM (Improving Direction Method) a due parti, il software realizza un agente in grado di manipolare a proprio vantaggio la negoziazione sfruttando le informazioni sulla controparte che il mediatore (deterministico) indirettamente fornisce ad ogni passo del processo di negoziazione
On the Actual Inefficiency of Efficient Negotiation Methods
No full textIn this contribution we analyze the effect that mutual information has on the actual performance of efficient negotiation methods. Specifically, we start by proposing the theoretical notion of Abstract Negotiation Method (ANM) as a map from the negotiation domain in itself, for any utility profile of the parties. ANM can face both direct and iterative negotiations, since we show that ANM class is closed under the limit operation. The generality of ANM is proven by showing that it captures a large class of well known in literature negotiation methods like: the Nash’s bargaining solution, all the methods derived by multi criteria decision theory and, in particular, the ones based on Lagrange multipliers, the Single Negotiating Text which was used in the Camp David Accords, the Improving Direction Method, and so on. Hence we show that if mutual information is assumed then any Pareto efficient ANM is manipulable by one single party or by a collusion of few of them.
At this point, we concern about the efficiency of the resulting manipulation. Thus we find necessary and sufficient conditions those make manipulability equivalent to actual inefficiency, meaning that the manipulation implies a change of the efficient frontier so the Pareto efficient ANM converges to a different, hence actually inefficient, frontier.
In particular we distinguish between strong and weak actual inefficiency. Where, the strong actual inefficiency is a drawback which is not possible to overcome of the ANMs, like the Pareto invariant one, so its negotiation result is invariant for any two profiles of utility which share the same Pareto frontier, we present. While the weak actual inefficiency is a drawback of any mathematical theorization on rational agents which constrain in a particular way their space of utility functions.
For the weak actual inefficiency we then state a principle of Result’s Inconsistency by showing that to falsify theoretical hypotheses is rational for any agent which is informed about the preference of the other, even if the theoretical assumptions, which constrain the space of agents’ utilities, are exact in the reality, i.e. the preferences of each single agent are well modeled. In essence we show that, under weak actual inefficiency assumption, any mathematical model which correctly capture the reality, it produces inconsistent results
An improved two-party negotiation over continues issues method secure against manipulatory behavior
No full textThis contribution focuses on two-party negotiation over continuous issues. We firstly prove two drawbacks of the jointly Improving
Direction Method (IDM), namely that IDM is not a Strategy-Proof
(SP) nor an Information Concealing (IC) method. Thus we prove that
the concurrent lack of these two properties implies the actual non-
efficiency of IDM. Finally we propose a probabilistic method which
is both IC and stochastically SP thus leading to efficient settlements
without being affected by manipulatory behaviors
The effect of information on the performance of negotiation models
No full textNegotiation is an everyday task in economic processes; ranging from corporations to markets, from agents to nations, always there is the need to mediate between conflicting intents or expectations. Therefore, in the scientific literature and in practice, several negotiation procedures have been developed, each one elaborated to perform in a specific context and under particular assumptions, as, for example, voting systems, auction and fair division mechanisms, negotiation protocols, and so on. All these may seem disjoined from each other, as their contexts are; nevertheless they all share the same assumption that each subject pursues his own best utility. Moreover, despite their specialization, they all have some problems in practical use like, for example, the presence of a dictator, the lack of truthfulness, or the possibility of being manipulated by fictitious declarations.
In this contribution we focus on the negotiation over continuous issues and in particular we analyze the jointly Improving Direction Method (IDM), which is known for its generality, since different other negotiation protocols can be seen as an its particular subclass, and also because it has the nice theoretical property of being Pareto efficient. Nevertheless it is easy to implement, which makes IDM the perfect candidate for an automated negotiation support system.
Despite its theoretical properties, we show the practical inefficiency of this method (even in the simple case of just two negotiating parties), which reduces significantly its performance in the operative context. In particular we show that the main drawback of IDM is due to the possibility to retrieve information about other ones utilities during the negotiation steps and to exploit it to manipulate the negotiation itself. For better explaining this phenomenon we show the deep connection between negotiation and the social choice problem. The bridge we build allows to carry in this context the Arrow’s Impossibility Theorem and the Gibbard-Satterthwaite Theorem, thus implying that each step of IDM (and of all the methods which it generalizes) may be affected by a dictatorial or a manipulatory party who can deviate the efficient Pareto frontier to get a better gain during the negotiation.
In order to avoid the operative inefficiency of IDM, we propose a different negotiation paradigm, where the hypothesis that agents maximize their own utility is not modified, while the way they pursuit maximum satisfaction is substantially different, since each agent has to express a sub optimal choice, rather than his optimal one. In this context, the constraint of a sub optimal declaration by one side protects from information retrieval and by the other side it forces each party to leave to the others the possibility to improve their own gains in order to pursue his own best.
The comparison of the performances with the IDM ones in different negotiation domains, both in terms of Pareto efficiency and manipulation resistance, shows the effectiveness of the proposed approach
An enhanced approach for developing an expert system for fund raising management
No full textIn social economy a great attention is devoted to non profit organizations, whose mission’s fulfillment is strongly related to the success of fund raising strategies. Then a decision support system for optimizing them is very useful. Using associations donors database a fuzzy expert system has been developed, which is able to suggest the best strategies with respect to donors profiles. This system integrates the profiles with a model for historical information evaluation and operative rules suggested by experts in the field and related literature.
There are however many little and medium size organizations which don’t own or efficiently manage the donors database. In these cases another approach has been proposed, which is able to individuate the most promising raising strategies on the basis of the features of the association. The profile factors of a non profit association are widely explored and hierarchically organized in a decision tree, in order to effectively employ the Choquet integral methodology, which is recommended in these kind of multi-criteria decision problems.
In the present contribution, some extensions are developed in order to enhance the first approach. In particular an integration with the second methodology is proposed, by substituting some fuzzy components with a hierarchic organization of the knowledge, that allows to use also in this context the Choquet integral, with an improvement of the tuning process and of the computational effort required. Moreover a wide analysis of donors features is performed; the donors interests evolution is managed, allowing a more precise characterization of the donors profile; an utility function approach is developed as extension of the expected gift model; new elements in the management process are modeled. The results obtained in a real operational context show the effectiveness of the proposed improvements
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
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