25,983 research outputs found
Truthful Computation Offloading Mechanisms for Edge Computing
Edge computing (EC) is a promising paradigm providing a distributed computing
solution for users at the edge of the network. Preserving satisfactory quality
of experience (QoE) for users when offloading their computation to EC is a
non-trivial problem. Computation offloading in EC requires jointly optimizing
access points (APs) allocation and edge service placement for users, which is
computationally intractable due to its combinatorial nature. Moreover, users
are self-interested, and they can misreport their preferences leading to
inefficient resource allocation and network congestion. In this paper, we
tackle this problem and design a novel mechanism based on algorithmic mechanism
design to implement a system equilibrium. Our mechanism assigns a proper pair
of AP and edge server along with a service price for each new joining user
maximizing the instant social surplus while satisfying all users' preferences
in the EC system. Declaring true preferences is a weakly dominant strategy for
the users. The experimental results show that our mechanism outperforms user
equilibrium and random selection strategies in terms of the experienced
end-to-end latency
Generating Diophantine Sets by Virus Machines
Virus Machines are a computational paradigm inspired by
the manner in which viruses replicate and transmit from one host cell to
another. This paradigm provides non-deterministic sequential devices.
Non-restricted virus machines are unbounded virus machines, in the
sense that no restriction on the number of hosts, the number of instructions
and the number of viruses contained in any host along any computation
is placed on them. The computational completeness of these
machines has been obtained by simulating register machines. In this
paper, virus machines as set generating devices are considered. Then,
the universality of non-restricted virus machines is proved by showing
that they can compute all diophantine sets, which the MRDP theorem
proves that coincide with the recursively enumerable sets.Ministerio de Economía y Competitividad TIN2012- 3743
Bounding Run-Times of Local Adiabatic Algorithms
A common trick for designing faster quantum adiabatic algorithms is to apply
the adiabaticity condition locally at every instant. However it is often
difficult to determine the instantaneous gap between the lowest two
eigenvalues, which is an essential ingredient in the adiabaticity condition. In
this paper we present a simple linear algebraic technique for obtaining a lower
bound on the instantaneous gap even in such a situation. As an illustration, we
investigate the adiabatic unordered search of van Dam et al. (How powerful is
adiabatic quantum computation? Proc. IEEE FOCS, pp. 279-287, 2001) and Roland
and Cerf (Physical Review A 65, 042308, 2002) when the non-zero entries of the
diagonal final Hamiltonian are perturbed by a polynomial (in , where
is the length of the unordered list) amount. We use our technique to derive
a bound on the running time of a local adiabatic schedule in terms of the
minimum gap between the lowest two eigenvalues.Comment: 11 page
Computing Partial Recursive Functions by Virus Machines
Virus Machines are a computational paradigm inspired by
the manner in which viruses replicate and transmit from one host cell to
another. This paradigm provides non-deterministic sequential devices.
Non-restricted Virus Machines are unbounded Virus Machines, in the
sense that no restriction on the number of hosts, the number of instructions
and the number of viruses contained in any host along any computation
is placed on them. The computational completeness of these
machines has been obtained by simulating register machines. In this
paper, Virus Machines as function computing devices are considered.
Then, the universality of non-restricted virus machines is proved by showing
that they can compute all partial recursive functions.Ministerio de Economía y Competitividad TIN2012- 3743
Computing with viruses
In recent years, different computing models have emerged within the area of Unconven-tional Computation, and more specifically within Natural Computing, getting inspiration from mechanisms present in Nature. In this work, we incorporate concepts in virology and theoretical computer science to propose a novel computational model, called Virus Ma-chine. Inspired by the manner in which viruses transmit from one host to another, a virus machine is a computational paradigm represented as a heterogeneous network that con-sists of three subnetworks: virus transmission, instruction transfer, and instruction-channel control networks. Virus machines provide non-deterministic sequential devices. As num-ber computing devices, virus machines are proved to be computationally complete, that is, equivalent in power to Turing machines. Nevertheless, when some limitations are imposed with respect to the number of viruses present in the system, then a characterization for semi-linear sets is obtained
Robust visual servoing in 3d reaching tasks
This paper describes a novel approach to the problem of reaching an object in space under visual guidance. The approach is characterized by a great robustness to calibration errors, such that virtually no calibration is required. Servoing is based on binocular vision: a continuous measure of the end-effector motion field, derived from real-time computation of the binocular optical flow over the stereo images, is compared with the actual position of the target and the relative error in the end-effector trajectory is continuously corrected. The paper outlines the general framework of the approach, shows how visual measures are obtained and discusses the synthesis of the controller along with its stability analysis. Real-time experiments are presented to show the applicability of the approach in real 3-D applications
Entropy generation in a model of reversible computation
We present a model in which, due to the quantum nature of the signals
controlling the implementation time of successive unitary computational steps,
\emph{physical} irreversibility appears in the execution of a \emph{logically}
reversible computation.Comment: 13 pages, 6 figure
Wait-Free Global Virtual Time Computation in Shared Memory Time-Warp Systems
Global Virtual Time (GVT) is a powerful abstraction used to discriminate what events belong (and what do not belong) to the past history of a parallel/distributed computation. For high performance simulation systems based on the Time Warp synchronization protocol, where concurrent simulation objects are allowed to process their events speculatively and causal consistency is achieved via rollback/recovery techniques, GVT is used to determine which portion of the simulation can be considered as committed. Hence it is the base for actuating memory recovery (e.g. of obsolete logs that were taken in order to support state recoverability) and nonrevocable operations (e.g. I/O). For shared memory implementations of simulation platforms based on the Time Warp protocol, the reference GVT algorithm is the one presented by Fujimoto and Hybinette [1]. However, this algorithm relies on critical sections that make it non-wait-free, and which can hamper scalability. In this article we present a waitfree shared memory GVT algorithm that requires no critical section. Rather, correct coordination across the processes while computing the GVT value is achieved via memory atomic operations, namely compare-and-swap. The price paid by our proposal is an increase in the number of GVT computation phases, as opposed to the single phase required by the proposal in [1]. However, as we show via the results of an experimental study, the wait-free nature of the phases carried out in our GVT algorithm pays-off in reducing the actual cost incurred by the proposal in [1]
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