scholarly journals Utilization Bound Scheduling Analysis for Nonpreemptive Uniprocessor Architecture Using UML-RT

2014 ◽  
Vol 2014 ◽  
pp. 1-11
Author(s):  
S. Ewins Pon Pushpa ◽  
Manamalli Devasigamani
Keyword(s):  
Release Time ◽  
Periodic Tasks ◽  
Task Set ◽  
Processor Utilization ◽  
Window Analysis ◽  
Rate Monotonic ◽  
Utilization Bound ◽  
Priority Scheme ◽  
Schedulability Test ◽  
Necessary And Sufficient

The key for adopting the utilization-based schedulability test is to derive the utilization bound. Given the computation times, this paper proposes two utilization bound algorithms to derive interrelease times for nonpreemptive periodic tasks, using a new priority scheme, “Rate Monotonic Algorithm-Shortest Job First.” The obtained task set possesses the advantage of Rate Monotonic Algorithm and Shortest Job First priority scheme. Further, the task set is tested for schedulability, by first deriving a general schedulability condition from “problem window” analysis and, a necessary and sufficient schedulability condition for a task to be scheduled, at any release time are also derived. As a technical contribution, success ratio and effective processor utilization are analyzed for our proposed utilization bound algorithms on a uniprocessor architecture modeled using UML-RT.

scholarly journals Schedulability of Rate Monotonic Algorithm using Improved Time Demand Analysis for Multiprocessor Environment

2018 ◽  
Vol 8 (1) ◽  
pp. 429
Author(s):  
Leena Das ◽  
Sourav Mohapatra ◽  
Durga Prasad Mohapatra
Keyword(s):  
Real Time ◽  
Scheduling Algorithm ◽  
Demand Analysis ◽  
Priority Scheduling ◽  
Task Set ◽  
Rate Monotonic ◽  
Test Algorithm ◽  
Task Sets ◽  
Number Of Iterations ◽  
Better Than

<p>Real-Time Monotonic algorithm (RMA) is a widely used static priority scheduling algorithm. For application of RMA at various systems, it is essential to determine the system’s feasibility first. The various existing algorithms perform the analysis by reducing the scheduling points in a given task set. In this paper we propose a schedubility test algorithm, which reduces the number of tasks to be analyzed instead of reducing the scheduling points of a given task. This significantly reduces the number of iterations taken to compute feasibility. This algorithm can be used along with the existing algorithms to effectively reduce the high complexities encountered in processing large task sets. We also extend our algorithm to multiprocessor environment and compare number of iterations with different number of processors. This paper then compares the proposed algorithm with existing algorithm. The expected results show that the proposed algorithm performs better than the existing algorithms.</p>

Utilization bound for periodic task set with composite deadline

2010 ◽  
Vol 36 (6) ◽  
pp. 1101-1109 ◽  
Author(s):  
Nasro Min-Allah ◽  
Ishtiaq Ali ◽  
Jiansheng Xing ◽  
Yongji Wang
Keyword(s):  
Task Set ◽  
Periodic Task ◽  
Utilization Bound

Scheduling of Periodic Tasks with Data Dependency on Multiprocessors

2013 ◽  
Vol 756-759 ◽  
pp. 2131-2136
Author(s):  
Jin Lin Wang
Keyword(s):  
Time Constraints ◽  
Release Time ◽  
Data Dependency ◽  
Scheduling Problem ◽  
Periodic Tasks ◽  
Dataflow Graphs ◽  
Time Limits ◽  
Static Schedule ◽  
Data Constraints ◽  
Synchronous Dataflow Graphs

This article studies the scheduling problem of a set of tasks with time or data constraints on a number of identical processors with full connections. We present an algorithm, in which a set of static schedule lists can be obtained, each for a processor, such that each task starts executing after its release time and completes its computation before its deadline, and all the precedence relations between tasks resulting from data dependency are satisfied. The data dependency relations between tasks are represented by Synchronous Dataflow Graphs (SDF) as they can indicate tasks concurrency and enable effective scheduling on multiprocessor platforms. The SDF, however, does not support the time constraints of tasks directly, thus an adaption is applied to conform to the time limits. With this adaption, the periodic tasks of implicit-deadline or constrained-deadline can be scheduled on multiprocessor platform effectively.

scholarly journals Distinguishability times and asymmetry monotone-based quantum speed limits in the Bloch ball

Quantum ◽  
2018 ◽  
Vol 2 ◽  
pp. 96 ◽  
Author(s):  
T.J. Volkoff ◽  
K.B. Whaley
Keyword(s):  
Error Probability ◽  
Quantum Systems ◽  
Qubit State ◽  
Release Time ◽  
Minimal Error ◽  
Two Level Systems ◽  
New Type ◽  
Time Required ◽  
Necessary And Sufficient ◽  
Qubit States

For both unitary and open qubit dynamics, we compare asymmetry monotone-based bounds on the minimal time required for an initial qubit state to evolve to a final qubit state from which it is probabilistically distinguishable with fixed minimal error probability (i.e., the minimal error distinguishability time). For the case of unitary dynamics generated by a time-independent Hamiltonian, we derive a necessary and sufficient condition on two asymmetry monotones that guarantees that an arbitrary state of a two-level quantum system or a separable state of N two-level quantum systems will unitarily evolve to another state from which it can be distinguished with a fixed minimal error probability δ∈[0,1/2]. This condition is used to order the set of qubit states based on their distinguishability time, and to derive an optimal release time for driven two-level systems such as those that occur, e.g., in the Landau-Zener problem. For the case of non-unitary dynamics, we compare three lower bounds to the distinguishability time, including a new type of lower bound which is formulated in terms of the asymmetry of the uniformly time-twirled initial system-plus-environment state with respect to the generator HSE of the Stinespring isometry corresponding to the dynamics, specifically, in terms of ‖[HSE,ρav(τ)]‖1, where ρav(τ):=1τ∫0τdte−iHSEtρ⊗|0⟩E⟨0|EeiHSEt.

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