11,886 research outputs found
Algorithms for Manipulating Sequential Allocation
Sequential allocation is a simple and widely studied mechanism to allocate
indivisible items in turns to agents according to a pre-specified picking
sequence of agents. At each turn, the current agent in the picking sequence
picks its most preferred item among all items having not been allocated yet.
This problem is well-known to be not strategyproof, i.e., an agent may get more
utility by reporting an untruthful preference ranking of items. It arises the
problem: how to find the best response of an agent?
It is known that this problem is polynomially solvable for only two agents
and NP-complete for arbitrary number of agents.
The computational complexity of this problem with three agents was left as an
open problem. In this paper, we give a novel algorithm that solves the problem
in polynomial time for each fixed number of agents. We also show that an agent
can always get at least half of its optimal utility by simply using its
truthful preference as the response
A study of systems implementation languages for the POCCNET system
The results are presented of a study of systems implementation languages for the Payload Operations Control Center Network (POCCNET). Criteria are developed for evaluating the languages, and fifteen existing languages are evaluated on the basis of these criteria
Bayesian Incentive Compatibility via Fractional Assignments
Very recently, Hartline and Lucier studied single-parameter mechanism design
problems in the Bayesian setting. They proposed a black-box reduction that
converted Bayesian approximation algorithms into Bayesian-Incentive-Compatible
(BIC) mechanisms while preserving social welfare. It remains a major open
question if one can find similar reduction in the more important
multi-parameter setting. In this paper, we give positive answer to this
question when the prior distribution has finite and small support. We propose a
black-box reduction for designing BIC multi-parameter mechanisms. The reduction
converts any algorithm into an eps-BIC mechanism with only marginal loss in
social welfare. As a result, for combinatorial auctions with sub-additive
agents we get an eps-BIC mechanism that achieves constant approximation.Comment: 22 pages, 1 figur
Pointer Race Freedom
We propose a novel notion of pointer race for concurrent programs
manipulating a shared heap. A pointer race is an access to a memory address
which was freed, and it is out of the accessor's control whether or not the
cell has been re-allocated. We establish two results. (1) Under the assumption
of pointer race freedom, it is sound to verify a program running under explicit
memory management as if it was running with garbage collection. (2) Even the
requirement of pointer race freedom itself can be verified under the
garbage-collected semantics. We then prove analogues of the theorems for a
stronger notion of pointer race needed to cope with performance-critical code
purposely using racy comparisons and even racy dereferences of pointers. As a
practical contribution, we apply our results to optimize a thread-modular
analysis under explicit memory management. Our experiments confirm a speed-up
of up to two orders of magnitude
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