2,178 research outputs found
Budget Feasible Mechanisms for Experimental Design
In the classical experimental design setting, an experimenter E has access to
a population of potential experiment subjects , each
associated with a vector of features . Conducting an experiment
with subject reveals an unknown value to E. E typically assumes
some hypothetical relationship between 's and 's, e.g., , and estimates from experiments, e.g., through linear
regression. As a proxy for various practical constraints, E may select only a
subset of subjects on which to conduct the experiment.
We initiate the study of budgeted mechanisms for experimental design. In this
setting, E has a budget . Each subject declares an associated cost to be part of the experiment, and must be paid at least her cost. In
particular, the Experimental Design Problem (EDP) is to find a set of
subjects for the experiment that maximizes V(S) = \log\det(I_d+\sum_{i\in
S}x_i\T{x_i}) under the constraint ; our objective
function corresponds to the information gain in parameter that is
learned through linear regression methods, and is related to the so-called
-optimality criterion. Further, the subjects are strategic and may lie about
their costs.
We present a deterministic, polynomial time, budget feasible mechanism
scheme, that is approximately truthful and yields a constant factor
approximation to EDP. In particular, for any small and , we can construct a (12.98, )-approximate mechanism that is
-truthful and runs in polynomial time in both and
. We also establish that no truthful,
budget-feasible algorithms is possible within a factor 2 approximation, and
show how to generalize our approach to a wide class of learning problems,
beyond linear regression
Quantum Games and Quantum Strategies
We investigate the quantization of non-zero sum games. For the particular
case of the Prisoners' Dilemma we show that this game ceases to pose a dilemma
if quantum strategies are allowed for. We also construct a particular quantum
strategy which always gives reward if played against any classical strategy.Comment: 4 pages, 4 figures, typographic sign error in the definition of the
operator J correcte
Quantum Games
In these lecture notes we investigate the implications of the identification
of strategies with quantum operations in game theory beyond the results
presented in [J. Eisert, M. Wilkens, and M. Lewenstein, Phys. Rev. Lett. 83,
3077 (1999)]. After introducing a general framework, we study quantum games
with a classical analogue in order to flesh out the peculiarities of game
theoretical settings in the quantum domain. Special emphasis is given to a
detailed investigation of different sets of quantum strategies.Comment: 13 pages (LaTeX), 3 figure
The basic approval voting game
We survey results about Approval Voting obtained within the standard framework of game theory. Restricting the set of strategies to undominated and sincere ballots does not help to predict Approval Voting outcomes, which is also the case under strategic equilibrium concepts such as Nash equilibrium and its usual refinements. Strong Nash equilibrium in general does not exist but predicts the election of a Condorcet winner when one exists
Sequential pivotal mechanisms for public project problems
It is well-known that for several natural decision problems no budget
balanced Groves mechanisms exist. This has motivated recent research on
designing variants of feasible Groves mechanisms (termed as `redistribution of
VCG (Vickrey-Clarke-Groves) payments') that generate reduced deficit. With this
in mind, we study sequential mechanisms and consider optimal strategies that
could reduce the deficit resulting under the simultaneous mechanism. We show
that such strategies exist for the sequential pivotal mechanism of the
well-known public project problem. We also exhibit an optimal strategy with the
property that a maximal social welfare is generated when each player follows
it. Finally, we show that these strategies can be achieved by an implementation
in Nash equilibrium.Comment: 19 pages. The version without the appendix will appear in the Proc.
2nd International Symposium on Algorithmic Game Theory, 200
On Budget-Feasible Mechanism Design for Symmetric Submodular Objectives
We study a class of procurement auctions with a budget constraint, where an
auctioneer is interested in buying resources or services from a set of agents.
Ideally, the auctioneer would like to select a subset of the resources so as to
maximize his valuation function, without exceeding a given budget. As the
resources are owned by strategic agents however, our overall goal is to design
mechanisms that are truthful, budget-feasible, and obtain a good approximation
to the optimal value. Budget-feasibility creates additional challenges, making
several approaches inapplicable in this setting. Previous results on
budget-feasible mechanisms have considered mostly monotone valuation functions.
In this work, we mainly focus on symmetric submodular valuations, a prominent
class of non-monotone submodular functions that includes cut functions. We
begin first with a purely algorithmic result, obtaining a
-approximation for maximizing symmetric submodular functions
under a budget constraint. We view this as a standalone result of independent
interest, as it is the best known factor achieved by a deterministic algorithm.
We then proceed to propose truthful, budget feasible mechanisms (both
deterministic and randomized), paying particular attention on the Budgeted Max
Cut problem. Our results significantly improve the known approximation ratios
for these objectives, while establishing polynomial running time for cases
where only exponential mechanisms were known. At the heart of our approach lies
an appropriate combination of local search algorithms with results for monotone
submodular valuations, applied to the derived local optima.Comment: A conference version appears in WINE 201
Adaptive mechanism design and game theoretic analysis of auction-driven dynamic spectrum access in cognitive radio networks
The Ambivalence of Promising Technology
Issues of responsibility in the world of nanotechnology are becoming explicit with the emergence of a discourse on ‘responsible development’ of nanoscience and nanotechnologies. Much of this discourse centres on the ambivalences of nanotechnology and of promising technology in general. Actors must find means of dealing with these ambivalences. Actors’ actions and responses to ambivalence are shaped by their position and context, along with strategic games they are involved in, together with other actors. A number of interviews were conducted with industrial actors with the aim of uncovering their ethical stances towards responsible development of nanotechnology. The data shows that standard repertoires of justification of nanotechnological development were used. Thus, the industrial actors fell back on their position and associated responsibilities. Such responses reinforce a division of moral labour in which industrial actors and scientists can focus on the progress of science and technology, while other actors, such as NGOs, are expected to take care of broader considerations, such as ethical and social issues
Charge Transport in the Dense Two-Dimensional Coulomb Gas
The dynamics of a globally neutral system of diffusing Coulomb charges in two
dimensions, driven by an applied electric field, is studied in a wide
temperature range around the Berezinskii-Kosterlitz-Thouless transition. I
argue that the commonly accepted ``free particle drift'' mechanism of charge
transport in this system is limited to relatively low particle densities. For
higher densities, I propose a modified picture involving collective ``partner
transfer'' between bound pairs. The new picture provides a natural explanation
for recent experimental and numerical findings which deviate from standard
theory. It also clarifies the origin of dynamical scaling in this context.Comment: 4 pages, RevTeX, 2 eps figures included; some typos corrected, final
version to be published in Phys. Rev. Let
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