443,376 research outputs found
A Fully Polynomial-Time Approximation Scheme for Speed Scaling with Sleep State
We study classical deadline-based preemptive scheduling of tasks in a
computing environment equipped with both dynamic speed scaling and sleep state
capabilities: Each task is specified by a release time, a deadline and a
processing volume, and has to be scheduled on a single, speed-scalable
processor that is supplied with a sleep state. In the sleep state, the
processor consumes no energy, but a constant wake-up cost is required to
transition back to the active state. In contrast to speed scaling alone, the
addition of a sleep state makes it sometimes beneficial to accelerate the
processing of tasks in order to transition the processor to the sleep state for
longer amounts of time and incur further energy savings. The goal is to output
a feasible schedule that minimizes the energy consumption. Since the
introduction of the problem by Irani et al. [16], its exact computational
complexity has been repeatedly posed as an open question (see e.g. [2,8,15]).
The currently best known upper and lower bounds are a 4/3-approximation
algorithm and NP-hardness due to [2] and [2,17], respectively. We close the
aforementioned gap between the upper and lower bound on the computational
complexity of speed scaling with sleep state by presenting a fully
polynomial-time approximation scheme for the problem. The scheme is based on a
transformation to a non-preemptive variant of the problem, and a discretization
that exploits a carefully defined lexicographical ordering among schedules
Parameterized Algorithmics for Computational Social Choice: Nine Research Challenges
Computational Social Choice is an interdisciplinary research area involving
Economics, Political Science, and Social Science on the one side, and
Mathematics and Computer Science (including Artificial Intelligence and
Multiagent Systems) on the other side. Typical computational problems studied
in this field include the vulnerability of voting procedures against attacks,
or preference aggregation in multi-agent systems. Parameterized Algorithmics is
a subfield of Theoretical Computer Science seeking to exploit meaningful
problem-specific parameters in order to identify tractable special cases of in
general computationally hard problems. In this paper, we propose nine of our
favorite research challenges concerning the parameterized complexity of
problems appearing in this context
Benchmark Analysis of Representative Deep Neural Network Architectures
This work presents an in-depth analysis of the majority of the deep neural
networks (DNNs) proposed in the state of the art for image recognition. For
each DNN multiple performance indices are observed, such as recognition
accuracy, model complexity, computational complexity, memory usage, and
inference time. The behavior of such performance indices and some combinations
of them are analyzed and discussed. To measure the indices we experiment the
use of DNNs on two different computer architectures, a workstation equipped
with a NVIDIA Titan X Pascal and an embedded system based on a NVIDIA Jetson
TX1 board. This experimentation allows a direct comparison between DNNs running
on machines with very different computational capacity. This study is useful
for researchers to have a complete view of what solutions have been explored so
far and in which research directions are worth exploring in the future; and for
practitioners to select the DNN architecture(s) that better fit the resource
constraints of practical deployments and applications. To complete this work,
all the DNNs, as well as the software used for the analysis, are available
online.Comment: Will appear in IEEE Acces
A Survey on Continuous Time Computations
We provide an overview of theories of continuous time computation. These
theories allow us to understand both the hardness of questions related to
continuous time dynamical systems and the computational power of continuous
time analog models. We survey the existing models, summarizing results, and
point to relevant references in the literature
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