scholarly journals Mixed-mode Operating System for Real-time Performance

2017 ◽  
Vol 26 (1) ◽  
pp. 43-56
Author(s):  
M.M. Hasan ◽  
S. Sultana ◽  
C.K. Foo

The purpose of the mixed-mode system research is to handle devices with the accuracy of real-time systems and at the same time, having all the benefits and facilities of a matured Graphic User Interface (GUI) operating system which is typically nonreal-time. This mixed-mode operating system comprising of a real-time portion and a non-real-time portion was studied and implemented to identify the feasibilities and performances in practical applications (in the context of scheduled the real-time events). In this research an i8751 microcontroller-based hardware was used to measure the performance of the system in real-time-only as well as non-real-time-only configurations. The real-time portion is an 486DX-40 IBM PC system running under DOS-based realtime kernel and the non-real-time portion is a Pentium III based system running under Windows NT. It was found that mixed-mode systems performed as good as a typical realtime system and in fact, gave many additional benefits such as simplified/modular programming and load tolerance.

Author(s):  
Hasan M. M. ◽  
Sultana S. ◽  
Foo C.K.

The purpose of the mixed-mode system research is to handle devices with the accuracy of real-time systems and at the same time, having all the benefits and facilities of a matured Graphic User Interface(GUI)operating system which is typicallynon-real-time. This mixed-mode operating system comprising of a real-time portion and a non-real-time portion was studied and implemented to identify the feasibilities and performances in practical applications (in the context of scheduled the real-time events). In this research an i8751 microcontroller-based hardware was used to measure the performance of the system in real-time-only as well as non-real-time-only configurations. The real-time portion is an 486DX-40 IBM PC system running under DOS-based real-time kernel and the non-real-time portion is a Pentium IIIbased system running under Windows NT. It was found that mixed-mode systems performed as good as a typical real-time system and in fact, gave many additional benefits such as simplified/modular programming and load tolerance.


2021 ◽  
Vol 11 (1) ◽  
pp. 377
Author(s):  
Michele Scarpiniti ◽  
Enzo Baccarelli ◽  
Alireza Momenzadeh ◽  
Sima Sarv Ahrabi

The recent introduction of the so-called Conditional Neural Networks (CDNNs) with multiple early exits, executed atop virtualized multi-tier Fog platforms, makes feasible the real-time and energy-efficient execution of analytics required by future Internet applications. However, until now, toolkits for the evaluation of energy-vs.-delay performance of the inference phase of CDNNs executed on such platforms, have not been available. Motivated by these considerations, in this contribution, we present DeepFogSim. It is a MATLAB-supported software toolbox aiming at testing the performance of virtualized technological platforms for the real-time distributed execution of the inference phase of CDNNs with early exits under IoT realms. The main peculiar features of the proposed DeepFogSim toolbox are that: (i) it allows the joint dynamic energy-aware optimization of the Fog-hosted computing-networking resources under hard constraints on the tolerated inference delays; (ii) it allows the repeatable and customizable simulation of the resulting energy-delay performance of the overall Fog execution platform; (iii) it allows the dynamic tracking of the performed resource allocation under time-varying operating conditions and/or failure events; and (iv) it is equipped with a user-friendly Graphic User Interface (GUI) that supports a number of graphic formats for data rendering. Some numerical results give evidence for about the actual capabilities of the proposed DeepFogSim toolbox.


Author(s):  
Jörg Stöcklein ◽  
Daniel Baldin ◽  
Wolfgang Müller ◽  
Tao Xie

In our paper we present a virtual test environment for self-optimizing systems based on mutant based testing to validate user tasks of a real-time operating system. This allows the efficient validation of the code coverage of the test cases and therefore helps to detect errors in order to improving the reliability of the system software. Technically we are able to run and test the software on both systems. By writing application software and setting up the virtual test environment properly, we define our test cases. To validate the code coverage for our test cases, we use the approach of mutant based testing. By running this mutated code on our virtual prototype in the virtual test environment, we are able to efficiently validate the code coverage and are able to detect bugs in the application code or detect dead code that is not executed. Finding non-executing code leads to redefinition of our test cases by either changing the test environment or the application code in the case of dead code. We implemented the virtual test environment on top of the third party low cost VR system Unity 3D, which is frequently used in entertainment and education. We demonstrate our concepts by the example of our BeBot robot vehicles. The implementation is based on our self-optimizing real-time operating system ORCOS and we used the tool CERTITUDE(TM) for generating the mutations in our application code. Our BeBot virtual prototype in our virtual test environment implements the same low-level interface to the underlying hardware as the real BeBot. This allows a redirection of commands in ORCOS to either the real or the virtual BeBot in order to provide a VR based platform for early software development as well as ensures comparable conditions under both environments. Our example applies a virtual BeBot that drives through a labyrinth utilizing its IR sensors for navigation. The mutant based testing checks if all situations implemented by the software to navigate through the labyrinth are covered by our tests.


Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3346
Author(s):  
Mahmoud Hussein ◽  
Ahmed I. Galal ◽  
Emad Abd-Elrahman ◽  
Mohamed Zorkany

IoT-based applications operate in a client–server architecture, which requires a specific communication protocol. This protocol is used to establish the client–server communication model, allowing all clients of the system to perform specific tasks through internet communications. Many data communication protocols for the Internet of Things are used by IoT platforms, including message queuing telemetry transport (MQTT), advanced message queuing protocol (AMQP), MQTT for sensor networks (MQTT-SN), data distribution service (DDS), constrained application protocol (CoAP), and simple object access protocol (SOAP). These protocols only support single-topic messaging. Thus, in this work, an IoT message protocol that supports multi-topic messaging is proposed. This protocol will add a simple “brain” for IoT platforms in order to realize an intelligent IoT architecture. Moreover, it will enhance the traffic throughput by reducing the overheads of messages and the delay of multi-topic messaging. Most current IoT applications depend on real-time systems. Therefore, an RTOS (real-time operating system) as a famous OS (operating system) is used for the embedded systems to provide the constraints of real-time features, as required by these real-time systems. Using RTOS for IoT applications adds important features to the system, including reliability. Many of the undertaken research works into IoT platforms have only focused on specific applications; they did not deal with the real-time constraints under a real-time system umbrella. In this work, the design of the multi-topic IoT protocol and platform is implemented for real-time systems and also for general-purpose applications; this platform depends on the proposed multi-topic communication protocol, which is implemented here to show its functionality and effectiveness over similar protocols.


2014 ◽  
Vol 513-517 ◽  
pp. 2487-2491
Author(s):  
Dong Zhao ◽  
Shang Wei Jiang ◽  
Hong Wei Zhao ◽  
Xin Tong Yu

This paper combines the characteristics of real-time embedded systems and the real-time operating system to propose a software engineering method and process which bases on the function structured analysis and task structured design. First in the process of structured analysis based on the Hatley-Pirbhai method, extracting and sorting out the data flow and control flow according to the functional requirements of the system, analyzing and processing the functions of the system, the dependency among the functions and the timing sequence, and then realizing the design of the specific functions of the system, next achieving the structural design through the improving method, it also simplifies the system design processes. At this time, just need to analyze and divide the processing which is obtained from the structural analysis to get the specific task, design the interfaces among the tasks and also every task to get the new design method of the embedded real-time operating system, which also solves hard issue of the traditional method which is the weak extracting and developing iteration in the embedded real-time system.


2009 ◽  
Vol 626-627 ◽  
pp. 87-92
Author(s):  
X.H. Lu ◽  
Zhen Yuan Jia ◽  
Y.Z. Lv ◽  
J.Y. Yang

A design proposal for developing a high-precision timer of the real-time digital copying control system is put forward by analyzing the real-time characteristics of Windows 2000 operating system. Proposals of using information systems timer—WM_TIMER, multimedia timer, VxD and hardware to achieve high-precision timing in Windows operating system are analyzed and compared. Based on computer high-frequency timer and multi-thread technology, timing function provided by Microsoft Visual C++ is used to achieve a high-precision software timer of the system. Finally, the researched timing method is tested in Advantech IPC-610 host with Intel Pentium 4 processor, and the maximum timing error is less than 5μs which meets the system timing requirements.


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