scholarly journals FASDQ: Fault-Tolerant Adaptive Scheduling with Dynamic QoS-Awareness in Edge Containers for Delay-Sensitive Tasks

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 2973
Author(s):  
Ruifeng Wang ◽  
Ningjiang Chen ◽  
Xuyi Yao ◽  
Liangqing Hu
Keyword(s):  
Execution Time ◽  
Resource Constraints ◽  
Response Times ◽  
Fault Tolerant ◽  
Adaptive Scheduling ◽  
System Response ◽  
Time Data ◽  
Adaptive Adjustment ◽  
The Difference ◽  
Dynamic Quality

As the requirement for real-time data analysis increases, edge computing is being implemented to leverage the resources of edge devices to reduce system response times and decrease the latency. However, due to the resource constraints of edge clouds, edge servers are more prone to failures than other systems. Therefore, guaranteeing the reliability of services in edge clouds is critical. In this paper, we propose a fault-tolerant adaptive scheduling mechanism with dynamic quality of service (QoS) awareness (FASDQ), which extends the primary/backup (PB) model by applying QoS on demand to task copies. The aim of the method is to reduce the latency and achieve reliable service for tasks by changing the execution time of task copies. This paper also proposes a container resource-adaptive adjustment mechanism, which adjusts the timing of resources when the available resources cannot meet the task copy requirements. Finally, this paper reports the results of simulation experiments on the EdgeCloudSim platform to evaluate the difference in performance between FASDQ and other methods. The results show that the mechanism effectively reduces the execution time of task copies and outperforms other methods in terms of reliability and general resource utilization.

OPTIMAL VERSION SEQUENCING IN FAULT-TOLERANT PROGRAMS

2005 ◽  
Vol 22 (01) ◽  
pp. 1-18 ◽  
Author(s):  
GREGORY LEVITIN
Keyword(s):  
System Reliability ◽  
Execution Time ◽  
Resource Constraints ◽  
Fault Tolerant ◽  
Optimization Procedure ◽  
Moment Generating Function ◽  
Software Systems ◽  
Block Scheme ◽  
The Moment ◽  
Recovery Block

This paper considers software systems consisting of fault-tolerant components. These components are built from functionally equivalent but independently developed versions characterized by different reliability and execution times. Because of resource constraints, the number of versions that can run simultaneously is limited. The expected system execution time and its reliability (defined as probability of obtaining the correct output within a specified time) strictly depends on the sequence of versions execution. Different sequences can provide either maximal system reliability or minimal expected execution time. An optimization procedure is suggested for finding such sequences. The procedure is based on an algorithm for determining system execution time distribution that uses the moment generating function approach and on the genetic algorithm. Both N-version programming and the recovery block scheme are considered within a universal model. An illustrated example is presented.

On the Difference Between Monkeys' and Humans' Response Times: Could It Be the Experimental Procedure?

2012 ◽  
Author(s):  
Guy E. Hawkins ◽  
Birte U. Forstmann ◽  
Eric-Jan Wagenmakers ◽  
Scott D. Brown
Keyword(s):  
Response Times ◽  
Experimental Procedure ◽  
The Difference

scholarly journals Design of Auto-tuning Relay Feedback controller for Shell Heavy Oil Fractionator

2018 ◽  
Vol 218 ◽  
pp. 02007
Author(s):  
Wahyudi ◽  
Sela Martasia ◽  
Budi Setiyono ◽  
Iwan Setiawan
Keyword(s):  
Heavy Oil ◽  
System Modeling ◽  
Control Technique ◽  
System Response ◽  
Relay Feedback ◽  
End Point ◽  
Column Type ◽  
Point Composition ◽  
Auto Tuning ◽  
The Difference

Auto-tuning relay feedback is one of the control techniques, which is used to solve the non-linear, long delay time, and disturbance's problems. This control technique is the development of Ziegler-Nichols that can be done automatically without doing system modeling. In this paper, auto-tuning relay feedback is used in the control system response to optimization of Shell Heavy Oil Fractionator (SHOF) system so the output of product composition as expected. SHOF is a distillation column type used to separate crude oil into desired products based on the difference in the boiling point of each product. PI regulators of relay feedback are used to control the valves on the SHOF with three inputs and three outputs that has been decoupled. Based on the tests, the average values of IAE at top end point composition (Y1) obtained with disturbance and no disturbance are 83.17 and 10.933, respectively. At the side end point composition (Y2), the average values of IAE with disturbance and no disturbance are obtained respectively, 336.38 and 42.3467. The average values of IAE at bottom reflux temperature (Y3) with disturbance and no disturbance are obtained 0.15 and 0.13, respectively.

Beating Effects in a Single Nonlinear Dynamical System in a Neighborhood of the Resonance

2016 ◽  
Vol 849 ◽  
pp. 76-83
Author(s):  
Jiří Náprstek ◽  
Cyril Fischer
Keyword(s):  
Harmonic Balance ◽  
Excitation Frequency ◽  
Nonlinear Dynamical System ◽  
Numerical Continuation ◽  
System Response ◽  
Algebraic Equations ◽  
Single Degree Of Freedom ◽  
Nonlinear Dynamical ◽  
The Difference ◽  
Eigen Frequency

The exact coincidence of external excitation and basic eigen-frequency of a single degree of freedom (SDOF) nonlinear system produces stationary response with constant amplitude and phase shift. When the excitation frequency differs from the system eigen-frequency, various types of quasi-periodic response occur having a character of a beating process. The period of beating changes from infinity in the resonance point until a couple of excitation periods outside the resonance area. Theabove mentioned phenomena have been identified in many papers including authors’ contributions. Nevertheless, investigation of internal structure of a quasi-period and its dependence on the difference of excitation and eigen-frequency is still missing. Combinations of harmonic balance and small parameter methods are used for qualitative analysis of the system in mono- and multi-harmonic versions. They lead to nonlinear differential and algebraic equations serving as a basis for qualitativeanalytic estimation or numerical description of characteristics of the quasi-periodic system response. Zero, first and second level perturbation techniques are used. Appearance, stability and neighborhood of limit cycles is evaluated. Numerical phases are based on simulation processes and numerical continuation tools. Parametric evaluation and illustrating examples are presented.

scholarly journals Coupling Synchronization Criterion of Two Hydraulic Motors in an Eccentric Rotary Vibration Machine

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Chun-lei Luo ◽  
Xin Mo ◽  
Jin-yang Li ◽  
Zhi-qing Tang ◽  
Song-song Huang
Keyword(s):  
Influence Factors ◽  
Resistance Coefficient ◽  
System Response ◽  
Vibration Machine ◽  
Synchronous Motion ◽  
Hydraulic Motors ◽  
The Difference ◽  
Pressure Compensation ◽  
Coupling Characteristics ◽  
Vibration Coupling

In an eccentric rotating system driven by two hydraulic motors without synchronous gears, vibration coupling may help render motion stable. In order to investigate how vibration coupling influences the motion, the coupling characteristics of the vibration system were studied regarding the differences between two motors such as leakage network, coulomb damping network, and pressure loss network, and the sensitivity of the influence factors was also studied. The influence of tiny differences between the two motors, tiny differences in the motion pair structure, in the oil temperature and in the resistance coefficient on the coupling motion were discovered, and the criterion for synchronous motion were obtained consequently. The results show that the influence of the resistance coefficient difference on system motion stability is the greatest, accounting for 46.7%, and the influence of the difference in motion pair structure (e.g. motor piston clearance) is the second, accounting for 32.8%. For motors with displacement 80 ml/r, the condition of self-synchronization is that the difference in piston clearance between the two motors is equal to or smaller than 6 μm. Experiments have proved the correctness of the theory and showed that the synchronization can be achieved by leakage compensation, damping compensation, and back-pressure compensation of the external system by means of control when the motors rotate slowly enough for system response. The study shows that the coupling synchronous model can reduce the force of the gear for the eccentricity rotary system with synchronous gear, and that the synchronous stability can be improved for the eccentricity rotary system without synchronous gear.

scholarly journals Performance Analysis and Optimization Techniques for Oracle Relational Databases

2019 ◽  
Vol 19 (2) ◽  
pp. 117-132
Author(s):  
Fernando Almeida ◽  
Pedro Silva ◽  
Fernando Araújo
Keyword(s):  
Execution Time ◽  
Relational Databases ◽  
Database System ◽  
Optimization Techniques ◽  
Management Systems ◽  
System Response ◽  
Database Access ◽  
Data Manipulation ◽  
System Response Time ◽  
Analyze Data

Abstract Databases provide an efficient way to store, retrieve and analyze data. Oracle relational database is one of the most popular database management systems that is widely used in a different variety of industries and businesses. Therefore, it is important to guarantee that the database access and data manipulation is optimized for reducing database system response time. This paper intends to analyze the performance and the main optimization techniques (Forall, Returning, and Bulk Collect) that can be adopted for Oracle Relational Databases. The results have shown that the adoption of Forall and Bulk Collect approaches bring significant benefits in terms of execution time. Furthermore, the growth rate of the average execution time is lower for Bulk Collect than Forall. However, adoption of Returning approach doesn’t bring significant statistical benefits.

scholarly journals COMPARATIVE ANALYSIS OF XML AND JSON USING PHP APPLICATION PLATFORM WITH REPRESENTATIONAL STATE TRANSFER ( REST ) ARCHITECTURAL

Compiler ◽  
2013 ◽  
Vol 2 (2) ◽  
Author(s):  
Saryanto Saryanto ◽  
Sumarsono Sumarsono ◽  
Nurcahyani Dewi Retnowati
Keyword(s):  
Comparative Analysis ◽  
Web Service ◽  
Measurement Method ◽  
Data Communication ◽  
The Internet ◽  
Time Data ◽  
Xml Data ◽  
Data Measurement ◽  
The Difference ◽  
The Web

Data communication in the internet today is so complex as an example of the speed factor becomes very important in communicating, everyone wants fast data communication services provided in order to maximum. In relation to the application as a communication liaison with client server applications, web service using a data serialization format to transmit the data. Before the data is sent, either fromthe client to the server or vice versa, should be modified in a specific data format beforehand according to the web service is used. Types of data serialization format used in the web service such as XML and JSON. The method used for testing include data serialization method, data measurement method and data parsing method. Data serialization method is used to calculate the time serialization of data from the database to the form of XML and JSON in applications with PHP platform. Data measurement method used to measure the size of the XML and JSON data which based on many fields of data serialization process. Data parsing method is used to calculate the processing time and JSON parsing XML data. Results o f comparative analysis o f XML and JSON in PHP applications using thearchitecture Rest can be concluded that the test result o f the difference in time and time serialization and JSON parsing XML data is influenced by the number o f records, if the number of records the greater the difference in eating time data serialization and parsing the data the greater the time also itcan be concluded that the faster the process JSON serialization and parsing XML data is compared. Testing results o f the JSON data size is smaller than the size of XML. Data exchange using XML format has a size limit of up to 31456.31 KB while JSON XML exceeds the size limit. Testing results on the Internet when the number o f records up to 50,000 data when the data serialization and parsing time data can not be detected in the database.

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