81 research outputs found
An Efficient Protocol for Negotiation over Combinatorial Domains with Incomplete Information
We study the problem of agent-based negotiation in combinatorial domains. It
is difficult to reach optimal agreements in bilateral or multi-lateral
negotiations when the agents' preferences for the possible alternatives are not
common knowledge. Self-interested agents often end up negotiating inefficient
agreements in such situations. In this paper, we present a protocol for
negotiation in combinatorial domains which can lead rational agents to reach
optimal agreements under incomplete information setting. Our proposed protocol
enables the negotiating agents to identify efficient solutions using
distributed search that visits only a small subspace of the whole outcome
space. Moreover, the proposed protocol is sufficiently general that it is
applicable to most preference representation models in combinatorial domains.
We also present results of experiments that demonstrate the feasibility and
computational efficiency of our approach
Group recommender systems: A multi-agent solution
Providing recommendations to groups of users has become a promising research area, since many items tend to be consumed by groups of people. Various techniques have been developed aiming at making recommendations to a group as a whole. Most works use aggregation techniques to combine preferences, recommendations or profiles. However, satisfying all group members in an even way still remains as a challenge. To deal with this problem, we propose an extension of a multi-agent approach based on negotiation techniques for group recommendation. In the approach, we use the multilateral Monotonic Concession Protocol (MCP) to combine individual recommendations into a group recommendation. In this work, we extend the MCP protocol to allow users to personalize the behavior of the agents. This extension was evaluated in two different domains (movies and points of interest) with satisfactory results. We compared our approach against different baselines, namely: a preference aggregation algorithm, a recommendation aggregation algorithm, and a simple one-step negotiation. The results show evidence that, when using our negotiation approach, users in the groups are more uniformly satisfied than with traditional aggregation approaches.Fil: Villavicencio, Christian Paulo. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tandil. Instituto Superior de IngenierÃa del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierÃa del Software; ArgentinaFil: Schiaffino, Silvia Noemi. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tandil. Instituto Superior de IngenierÃa del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierÃa del Software; ArgentinaFil: Diaz Pace, Jorge Andres. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tandil. Instituto Superior de IngenierÃa del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierÃa del Software; ArgentinaFil: Monteserin, Ariel José. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro CientÃfico Tecnológico Conicet - Tandil. Instituto Superior de IngenierÃa del Software. Universidad Nacional del Centro de la Provincia de Buenos Aires. Instituto Superior de IngenierÃa del Software; Argentin
Automatic Multiagent Aircraft Collision Avoidance
In recent years, there have been incentives to move towards the Free Flight concept in aviation due to advances in technology and increasing air traffic. Free Flight proposes a distributed cooperative strategy based on direct communication between aircraft to maintain separation rather than the currently centralized manner that is handled by the air traffic controllers. Free Flight requires aircraft to be able to detect and resolve conflicts that could lead to loss of separation between multiple aircraft at any point during the flight, which proves to be a challenging task. This research seeks to find an optimized cooperative collision avoidance strategy to resolve conflicts in the horizontal and vertical planes by proposing maneuvers that involve changing the altitude or heading involving multiple aircraft. The method employed is to extend the Zeuthen strategy—an adaptation of the Monotonic Concession Protocol (MCP)—from pairwise negotiations to handle multiway conflicts. This coordinated strategy provides optimal change of trajectories through resolutions that maximize the product of agents’ utilities. We show with a simulator that this distributed approach is efficient and prevents losses of separation even in a highly congested airspace. The simulator also provides an infrastructure, on which alternative algorithms can be empirically evaluated
Bilateral negotiation of a meeting point in a maze
International audienceNegotiation between agents aims at reaching an agreement in which the conflicting interests of agents are accommodated. In this paper, we present a concrete negotiation scenario where two agents are situated in a maze and the negotiation outcome is a cell where they will meet. Based on their individual preferences (a minimal distance from their location computed from their partial knowledge of the environment), we propose a negotiation protocol which allows agents to submit more than two proposals at the same time and a conciliatory strategy. Formally, we prove that the agreement reached by such a negotiation process is Pareto- optimal and a compromise, i.e. a solution which minimizes the maximum effort for one agent. Moreover, the path between the two agents emerges from the repeated negotiations in our experiments
Enabling cooperative and negotiated energy exchange in remote communities
Energy poverty at the household level is defined as the lack of access to electricity and reliance on the traditional use of biomass for cooking, and is a serious hindrance to economic and social development. It is estimated that 1.3 billion people live without access to electricity and almost 2.7 billion people rely on biomass for cooking, a majority of whom live in small communities scattered over vast areas of land (mostly in the Sub-Saharan Africa and the developing Asia). Access to electricity is a serious issue as a number of socio-economic factors, from health to education, rely heavily on electricity. Recent initiatives have sought to provide these remote communities with off-grid renewable microgeneration infrastructure such as solar panels, and electric batteries. At present, these resources (i.e., microgeneration and storage) are operated in isolation for individual home needs, which results in an inefficient and costly use of resources, especially in the case of electric batteries which are expensive and have a limited number of charging cycles. We envision that by connecting homes together in a remote community and enabling energy exchange between them, this microgeneration infrastructure can be used more efficiently. Against this background, in this thesis we investigate the methods and processes through which homes in a remote community can exchange energy. We note that remote communities lack general infrastructure such as power supply systems (e.g., the electricity grid) or communication networks (e.g., the internet), that is taken for granted in urban areas. Taking these challenges into account and using insights from knowledge domains such game theory and multi-agent systems, we present two solutions: (i) a cooperative energy exchange solution and (ii) a negotiated energy exchange solution, in order to enable energy exchange in remote communities.Our cooperative energy exchange solution enables connected homes in a remote community to form a coalition and exchange energy. We show that such coalition a results in two surpluses: (i) reduction in the overall battery usage and (ii) reduction in the energy storage losses. Each agents's contribution to the coalition is calculated by its Shapley value or, by its approximated Shapley value in case of large communities. Using real world data, we empirically evaluate our solution to show that energy exchange: (i) can reduce the need for battery charging (by close to 65%) in a community; compared with when they do not exchange energy, and (ii) can improve the efficient use of energy (by up to 10% under certain conditions) compared with no energy exchange. Our negotiated energy exchange solution enables agents to negotiate directly with each other and reach energy exchange agreements. Negotiation over energy exchange is an interdependent multi-issue type of negotiation that is regarded as very difficult and complex. We present a negotiation protocol, named Energy Exchange Protocol (EEP), which simplifies this negotiation by restricting the offers that agents can make to each other. These restrictions are engineered such that agents, negotiation under the EEP, have a strategy profile in subgame perfect Nash equilibrium. We show that our negotiation protocol is tractable, concurrent, scalable and leads to Pareto-optimal outcomes (within restricted the set of offers) in a decentralised manner. Using real world data, we empirically evaluate our protocol and show that, in this instance, a society of agents can: (i) improve the overall utilities by 14% and (ii) reduce their overall use of the batteries by 37%, compared to when they do not exchange energy
Mechanism design for distributed task and resource allocation among self-interested agents in virtual organizations
The aggregate power of all resources on the Internet is enormous. The Internet can
be viewed as a massive virtual organization that holds tremendous amounts of information
and resources with different ownerships. However, little is known about how to run this
organization efficiently.
This dissertation studies the problems of distributed task and resource allocation
among self-interested agents in virtual organizations. The developed solutions are not
allocation mechanisms that can be imposed by a centralized designer, but decentralized
interaction mechanisms that provide incentives to self-interested agents to behave
cooperatively. These mechanisms also take computational tractability into consideration
due to the inherent complexity of distributed task and resource allocation problems.
Targeted allocation mechanisms can achieve global task allocation efficiency in a
virtual organization and establish stable resource-sharing communities based on agentsâÃÂÃÂ
own decisions about whether or not to behave cooperatively. This high level goal requires
solving the following problems: synthetic task allocation, decentralized coalition formation
and automated multiparty negotiation. For synthetic task allocation, in which each task needs to be accomplished by a
virtual team composed of self-interested agents from different real organizations, my
approach is to formalize the synthetic task allocation problem as an algorithmic mechanism
design optimization problem. I have developed two approximation mechanisms that I prove
are incentive compatible for a synthetic task allocation problem.
This dissertation also develops a decentralized coalition formation mechanism,
which is based on explicit negotiation among self-interested agents. Each agent makes its
own decisions about whether or not to join a candidate coalition. The resulting coalitions
are stable in the core in terms of coalition rationality. I have applied this mechanism to
form resource sharing coalitions in computational grids and buyer coalitions in electronic
markets.
The developed negotiation mechanism in the decentralized coalition formation
mechanism realizes automated multilateral negotiation among self-interested agents who
have symmetric authority (i.e., no mediator exists and agents are peers).
In combination, the decentralized allocation mechanisms presented in this
dissertation lay a foundation for realizing automated resource management in open and
scalable virtual organizations
Spatio-temporal Negotiation Protocols
Canonical problems are simplified representations of a class of real world problems. They allow researchers to compare algorithms in a standard setting which captures the most important challenges of the real world problems being modeled. In this dissertation, we focus on negotiating a collaboration in space and time, a problem with many important real world applications. Although technically a multi-issue negotiation, we show that the problem can not be represented in a satisfactory manner by previous models. We propose the Children in the Rectangular Forest (CRF) model as a possible canonical problem for negotiating spatio-temporal collaboration. In the CRF problem, two embodied agents are negotiating the synchronization of their movement for a portion of the path from their respective sources to destinations. The negotiation setting is zero initial knowledge and it happens in physical time. As equilibrium strategies are not practically possible, we are interested in strategies with bounded rationality, which achieve good performance in a wide range of practical negotiation scenarios. We design a number of negotiation protocols to allow agents to exchange their offers. The simple negotiation protocol can be enhanced by schemes in which the agents add additional information of the negotiation flow to aid the negotiation partner in offer formation. Naturally, the performance of a strategy is dependent on the strategy of the opponent and the iii characteristics of the scenario. Thus we develop a set of metrics for the negotiation scenario which formalizes our intuition of collaborative scenarios (where the agents’ interests are closely aligned) versus competitive scenarios (where the gain of the utility for one agent is paid off with a loss of utility for the other agent). Finally, we further investigate the sophisticated strategies which allow agents to learn the opponents while negotiating. We find strategies can be augmented by collaborativeness analysis: the approximate collaborativeness metric can be used to cut short the negotiation. Then, we discover an approach to model the opponent through Bayesian learning. We assume the agents do not disclose their information voluntarily: the learning needs to rely on the study of the offers exchanged during normal negotiation. At last, we explore a setting where the agents are able to perform physical action (movement) while the negotiation is ongoing. We formalize a method to represent and update the beliefs about the valuation function, the current state of negotiation and strategy of the opponent agent using a particle filter. By exploring a number of different negotiation protocols and several peer-to-peer negotiation based strategies, we claim that the CRF problem captures the main challenges of the real world problems while allows us to simplify away some of the computationally demanding but semantically marginal features of real world problems
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