arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2011.13133cs.GT
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$L_p$ 空间中2个智能体确定性策略证明机制的单设施选址问题的近完全刻画

Nearly Complete Characterization of 2-Agent Deterministic Strategyproof Mechanisms for Single Facility Location in $L_p$ Space

School of Computer Science, Fudan University(复旦大学计算机科学技术学院)

Jianan Lin

AI总结:

本文在 $L_p$ 空间中刻画了2个智能体确定性策略证明单设施选址机制,证明输出满足特定方程,并揭示了旋转不变性与独裁性等价,以及匿名机制的三种形式。

摘要:

我们考虑在 $L_p$ 空间($1<p<\infty$)中为2个智能体定位单个设施的问题,并给出了此类确定性策略证明机制的近完全刻画。我们用智能体与设施在 $L_p$ 空间中的距离来表示智能体的成本。一个机制是策略证明的,当且仅当没有智能体可以通过谎报其私人位置来降低其成本。我们证明,在 $L_p$ 空间($1<p<\infty$)中,对于2个智能体,任何确定性、一致、平移不变的策略证明机制的位置输出必须满足一组方程,并且这些机制是连续的、可缩放的。在一维空间中,输出必须是某个智能体的位置,这在任意 $n$ 个智能体的情况下都容易证明。然而,在 $m$ 维空间($m\ge 2$)中,情况要复杂得多,目前仅完成了2个智能体的情况。我们证明,此类机制的输出必须满足一组方程,并且当 $p=2$ 时,输出必须位于以两个智能体之间的线段为直径的球面上。进一步地,对于 $n$ 个智能体的情形,我们发现当维度 $m>2$ 时,2个智能体情形的简单推广无法成立,并证明著名的广义中位机制将给出一个反例。特别地,在 $L_2$(即欧几里得)空间中,对于2个智能体,此类机制是旋转不变的当且仅当它是独裁的;此类机制是匿名的当且仅当它是第4节中的三种机制之一。此外,我们的工具表明,在任何多维空间中,任何此类机制对于最大成本都具有2近似的紧下界。

英文摘要:

We consider the problem of locating a single facility for 2 agents in $L_p$ space ($1<p<\infty$) and give a nearly complete characterization of such deterministic strategyproof mechanisms. We use the distance between an agent and the facility in $L_p$ space to denote the cost of the agent. A mechanism is strategyproof iff no agent can reduce her cost from misreporting her private location. We show that in $L_p$ space ($1<p<\infty$) with 2 agents, any location output of a deterministic, unanimous, translation-invariant strategyproof mechanism must satisfy a set of equations and mechanisms are continuous, scalable. In one-dimensional space, the output must be one agent's location, which is easy to prove in any $n$ agents. However, in $m$-dimensional space ($m\ge 2$), the situation will be much more complex, with only 2-agent case finished. We show that the output of such a mechanism must satisfy a set of equations, and when $p=2$ the output must locate at a sphere with the segment between the two agents as the diameter. Further more, for $n$-agent situations, we find that the simple extension of this the 2-agent situation cannot hold when dimension $m>2$ and prove that the well-known general median mechanism will give an counter-example. Particularly, in $L_2$ (i.e., Euclidean) space with 2 agents, such a mechanism is rotation-invariant iff it is dictatorial; and such a mechanism is anonymous iff it is one of the three mechanisms in Section 4. And our tool implies that any such a mechanism has a tight lower bound of 2-approximation for maximum cost in any multi-dimensional space.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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