12533129
Procrastination for leakage-aware rate-monotonic scheduling on a dynamic voltage scaling processor
As the dynamic voltage scaling (DVS) technique provides system engineers the flexibility to trade-off the performance and the energy consumption, DVS has been adopted in many computing systems. However, the longer a job executes, the more energy in the leakage current the device/processor consumes for the job. To reduce the energy consumption resulting from the leakage current, a system might enter the dormant mode. This paper targets energy-efficient rate-monotonic scheduling for periodic real-time tasks on a uniprocessor DVS system with non-negligible leakage power consumption. An on-line simulated scheduling strategy and a virtually blocking time strategy are developed for procrastination scheduling to reduce energy consumption. The proposed algorithms derive a feasible schedule for real-time tasks with worst-case guarantees for any input instance. Experimental results show that our proposed algorithms could derive energy-efficient solutions.
30973700
Allocation cost minimization for periodic hard real-time tasks in energy-constrained DVS systems
5871408
Leakage-Aware Energy-Efficient Scheduling of Real-Time Tasks in Multiprocessor Systems
This work targets energy-efficient scheduling of periodic real-time tasks over multiple DVS processors with the considerations of power consumption due to leakage current. A polynomial-time algorithm with a 1.283 approximation bound is proposed when the overheads in turning on/off a processor are negligible. When the overheads are non-negligible, we develop polynomial-time algorithms with a 2 approximation bound. A series of simulation experiments was done for the performance evaluation of the proposed algorithms. The simulation results show that the proposed algorithms could derive schedules very close to optimal solutions.
3103973
Sprite: a simple, cheat-proof, credit-based system for mobile ad-hoc networks
Mobile ad hoc networking has been an active research area for several years. How to stimulate cooperation among selfish mobile nodes, however, is not well addressed yet. In this paper, we propose Sprite, a simple, cheat-proof, credit-based system for stimulating cooperation among selfish nodes in mobile ad hoc networks. Our system provides incentive for mobile nodes to cooperate and report actions honestly. Compared with previous approaches, our system does not require any tamper-proof hardware at any node. Furthermore, we present a formal model of our system and prove its properties. Evaluations of a prototype implementation show that the overhead of our system is small. Simulations and analysis show that mobile nodes can cooperate and forward each other's messages, unless the resource of each node is extremely low.
27347911
A simple linear time approximation algorithm for multi-processor job scheduling on four processors
Multiprocessor job scheduling problem has become increasingly interesting, for both theoretical study and practical applications. Theoretical study of the problem has made significant progress recently, which, however, seems not to imply practical algorithms for the problem, yet. Practical algorithms have been developed only for systems with three processors and the techniques seem difficult to extend to systems with more than three processors. This paper offers new observations and introduces new techniques for the multiprocessor job scheduling problem on systems with four processors. A very simple and practical linear time approximation algorithm of ratio bounded by 1.5 is developed for the multi-processor job scheduling problem P4|fix|Cmax, which significantly improves previous results. Our techniques are also useful for multiprocessor job scheduling problems on systems with more than four processors.
563848
An efficient parameterized algorithm for m-set packing
We present an efficient parameterized algorithm solving the Set Packing problem, in which we assume that the size of the sets is bounded by m. In particular, if the size m of the sets is bounded by a constant, then our algorithm is fixed-parameter tractable. For example, if the size of the sets is bounded by 3, then our algorithm runs in time O((5.7k)kn).
14208339
Using Nondeterminism to Design Efficient Deterministic Algorithms
Abstract
In this paper we illustrate how nondeterminism can be used
conveniently and effectively in designing efficient deterministic
algorithms. In particular, our method gives a parameterized
algorithm of running time O((5.7 k)k n) for the 3-D matching
problem, which significantly improves the previous algorithm by
Downey et al. The algorithm can be generalized to
yield an improved algorithm for the r-D matching problem for any
positive integer r. The method can also be employed in designing
deterministic algorithms for other optimization problems as well.


2221913
A Simple Linear-Time Approximation Algorithm for Multi-processor Job Scheduling on Four Processors
Multiprocessor job scheduling problem has become increasingly interesting, for both theoretical study and practical applications. Theoretical study of the problem has made significant progress recently, which, however, seems not to imply practical algorithms for the problem, yet. Practical algorithms have been developed only for systems with three processors and the techniques seem difficult to extend to systems with more than three processors. This paper offers new observations and introduces new techniques for the multiprocessor job scheduling problem on systems with four processors. A very simple and practical linear time approximation algorithm of ratio bounded by 1:5 is developed for the multi-processor job scheduling problem P4|fix|Cmax, which significantly improves previous results. Our techniques are also useful for multiprocessor job scheduling problems on systems with more than four processors.