Dynamic Soft Real-Time Scheduling with Preemption Threshold for Streaming Media

Over the last decades, the advancements in networking technology and new multimedia devices have motivated the research on efficient video streaming mechanisms under wireless. We consider combing soft real-time video streaming scheduling with threshold to minimize the ineffective preemption. Based on the value density and urgency of soft real-time task, the dynamic scheduling with preemption threshold strategy (DSPT) is proposed in the paper. By analyzing the response time and preemption relationship of tasks, the preemption thresholds are assigned. Simulation results show that the DSPT strategy achieves improvements about success rate, delay time, and benefit of the system.

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A Real-Time Scheduling Algorithm Based on Priority Table

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.756-759.3929 ◽

2013 ◽

Vol 756-759 ◽

pp. 3929-3936

Author(s):

Er Feng Su ◽

Kai Long Zhang ◽

Xing She Zhou ◽

Chen Fan

Keyword(s):

Real Time ◽

Dynamic Scheduling ◽

Heuristic Algorithms ◽

Scheduling Algorithm ◽

Task Type ◽

Real Time Scheduling ◽

Success Ratio ◽

Time Scheduling ◽

Definition Of ◽

Priority Table

Among preemptive real-time uniprocessor scheduling algorithms, many researches, such as optimal and heuristic algorithms, considers only one task attribute and neglects also the variation of attributes. To understand the relations between task attributes and scheduling success ratio, we first define the sensitivity of scheduling success ratio to task attributes. Sensitivity means the intensity of variation of scheduling success ratio as task attributes varies. The paper analyzes the sensitivities of scheduling success ratio to arrival time, execution time, deadline and laxity respectively, which have close relations with scheduling. Based on the definition of sensitivity, we also define attributes influence on scheduling success ratio, which is that the greater the influence, the higher the ratio. The essence of dynamic scheduling is a scheduling based on priority, with each dynamic algorithm matching a priority table, and vice versa. It is also much easier to infer the algorithm from the priority table, which can consider several task attributes. As priority table has various designs, it can correspond to a lot of algorithms, among which, many are inefficient. In order to deal with this kind of problem, we propose a new priority table design PTBM combining deadline and laxity based on the analysis of sensitivity and influence, which makes that a task with small deadline and large laxity has higher priority. We compare PTBM with EDF, LLF and PTD through simulation. The results verify the analysis of sensitivity and influence, and it also shows that PTBM outperforms on scheduling success ratio. It needs further exploration to design more efficient priority table by analyzing more task attributes influence on scheduling success ratio, which includes criticalness, task type and so on.

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Genealogy of hard real-time preemptive scheduling algorithms for identical multiprocessors

Open Computer Science ◽

10.2478/s13537-011-0023-z ◽

2011 ◽

Vol 1 (3) ◽

Cited By ~ 2

Author(s):

Dirk Müller ◽

Matthias Werner

Keyword(s):

Real Time ◽

Dynamic Scheduling ◽

Scheduling Algorithms ◽

Real Time Scheduling ◽

Context Switching ◽

Migration Dynamics ◽

Time Scheduling ◽

And Migration ◽

Hard Real Time ◽

Full Utilization

AbstractWith the advent of multi-core computer systems, real-time (RT) scheduling on multiprocessors (MPs) is gaining more and more practical relevance. Basic algorithms developed in the 1970s or earlier are strongly influential on state-of-the-art preemptive hard real-time scheduling algorithms. These relationships will be revealed and visualized by four genealogies. Here, the two classification dimensions prioritization dynamics and migration dynamics serve as a framework for the systematization. Finally, such genealogical reconstructions could even lead to the discovery of new algorithms. An extra look will be devoted to the group of fully dynamic scheduling algorithms with full migration in which algorithms can reach full utilization, neglecting scheduling and context switching overheads. The important question for a set of RT scheduling algorithms serving as a basis for more sophisticated ones will be dealt with.

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Real-time scheduling supporting VCR functionality for scalable video streaming

14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, 2003. PIMRC 2003. ◽

10.1109/pimrc.2003.1259232 ◽

2004 ◽

Cited By ~ 1

Author(s):

Kui Gao ◽

Yuan Zhang ◽

Wen Gao ◽

Simin He

Keyword(s):

Real Time ◽

Video Streaming ◽

Scalable Video ◽

Real Time Scheduling ◽

Time Scheduling ◽

Scalable Video Streaming

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Dynamic Scheduling with Processing Time Uncertainty Using the Mixture of Periodic Optimization and Real-time Scheduling

TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series C ◽

10.1299/kikaic.72.1630 ◽

2006 ◽

Vol 72 (717) ◽

pp. 1630-1637 ◽

Cited By ~ 2

Author(s):

Toru EGUCHI ◽

Fuminori OBA ◽

Shintarou KOZAKI ◽

Takeshi MURAYAMA

Keyword(s):

Real Time ◽

Processing Time ◽

Dynamic Scheduling ◽

Real Time Scheduling ◽

Time Uncertainty ◽

Time Scheduling

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Dynamic scheduling model for the construction industry

Built Environment Project and Asset Management ◽

10.1108/bepam-02-2019-0021 ◽

2019 ◽

Vol 10 (3) ◽

pp. 313-330

Author(s):

Amer Fahmy ◽

Tarek Hassan ◽

Hesham Bassioni ◽

Ronald McCaffer

Keyword(s):

Real Time ◽

Cost Efficiency ◽

Dynamic Scheduling ◽

Real Life ◽

Content Type ◽

Resources Management ◽

Real Time Scheduling ◽

Time Scheduling ◽

Labor Utilization

Purpose Basic project control through traditional methods is not sufficient to manage the majority of real-time events in most construction projects. The purpose of this paper is to propose a Dynamic Scheduling (DS) model that utilizes multi-objective optimization of cost, time, resources and cash flow, throughout project construction. Design/methodology/approach Upon reviewing the topic of DS, a worldwide internet survey with 364 respondents was conducted to define end-user requirements. The model was formulated and solution algorithms discussed. Verification was reported using predefined problem sets and a real-life case. Validation was performed via feedback from industry experts. Findings The need for multi-objective dynamic software optimization of construction schedules and the ability to choose among a set of optimal alternatives were highlighted. Model verification through well-known test cases and a real-life project case study showed that the model successfully achieved the required dynamic functionality whether under the small solved example or under the complex case study. The model was validated for practicality, optimization of various DS schedule quality gates, ease of use and software integration with contemporary project management practices. Practical implications Optimized real-time scheduling can provide better resources management including labor utilization and cost efficiency. Furthermore, DS contributes to optimum materials procurement, thus minimizing waste. Social implications Optimized real-time scheduling can provide better resources management including labor utilization and cost efficiency. Furthermore, DS contributes to optimum materials procurement, thus minimizing waste. Originality/value The paper illustrates the importance of DS in construction, identifies the user needs and overviews the development, verification and validation of a model that supports the generation of high-quality schedules beneficial to large-scale projects.

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