scholarly journals A Small Remark on Hilbert’s Finitist View of Divisibility and Kanovich-Okada-Scedrov’s Logical Analysis of Real-Time Systems

2020 ◽  
pp. 39-47
Author(s):  
Mitsuhiro Okada
Keyword(s):  
Real Time ◽  
Infinite Divisibility ◽  
Early History ◽  
Logical Analysis ◽  
Real Time Systems ◽  
Infinitely Divisible ◽  
Real Time System ◽  
Natural Event ◽  
History Of ◽  
Time Systems

Abstract Hilbert remarked in the introductory part of his most famous finitism address (1925  [1]) that “[t]he infinite divisibility of a continuum is an operation that is present only in our thought”, which means that no natural event or matter is infinitely divisible in reality. We recall that Scedrov’s group including the author started logical analysis of real time systems with the principle similar to Hilbert’s no-infinite divisibility claim, in  [2]. The author would like to note some early history of the group’s work on logical analysis of real time system as well as some remark related to Hilbert’s claim of no-infinite divisibility.

scholarly journals Internet of Things (IoT) Platform for Multi-Topic Messaging

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3346
Author(s):  
Mahmoud Hussein ◽  
Ahmed I. Galal ◽  
Emad Abd-Elrahman ◽  
Mohamed Zorkany
Keyword(s):  
Operating System ◽  
Internet Of Things ◽  
Real Time ◽  
Communication Protocol ◽  
Real Time Systems ◽  
Real Time System ◽  
Client Server ◽  
Iot Applications ◽  
Iot Platforms ◽  
Time Systems

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.

scholarly journals DARTSVIEW, A TOOLKIT FOR DARTS IN LABVIEW

2009 ◽  
Vol 12 (14) ◽  
pp. 69-76
Author(s):  
Hieu Khanh Ngo ◽  
Grolleau Emmanuel
Keyword(s):  
Real Time ◽  
Virtual Instrument ◽  
Design Method ◽  
Real Time Systems ◽  
Application Development ◽  
Development Environment ◽  
Real Time System ◽  
Temporal Validation ◽  
Control Command ◽  
Time Systems

DARTS (Design Approach for Real Time Systems) [4] is a software design method for real time systems. LabVIEW (Laboratory Virtual Instrument Engineering Workbench) is a graphical application development environment developed by National Instruments Corporation based on the dataflow representation of the "G" language [6][2]. LabVIEW is implicitly multithreaded and has high level functions for communication/synchronization, allowing it to be used as a programming language for control/command and soft real-time applications. In order to help a designer to develop a real-time application, we propose the library DARTSVIEW, which simplifies the passage from the conception of a "multitasking" application to the implementation [8). One can use DARTSVIEW in different phases of the life cycle of real-time system software. The last version of DARTSVIEW, allows to define in XML several real-time programming normalized languages, and to generate a part of the code for different specific programming languages (Ada, POSIX 1003.1, VxWorks, OSEK/VDX, etc.). The flexibility introduced by the use of XML allows a designer also to generate some code targeting real-time scheduling analysis tools in order to achieve the temporal validation. The objective of this article is to present an overview of DARTSVIEW, a Toolkit for DARTS in LabVIEW, the role of DARTSVIEW in the software.

scholarly journals An Introduction to RTOS

2012 ◽  
pp. 285-289
Author(s):  
Sanjay Singh ◽  
Nishant Tripathi ◽  
Anil Kumar Chaudhary ◽  
Mahesh Kumar Singh
Keyword(s):  
Operating System ◽  
Real Time ◽  
Level Of Service ◽  
Real Time Systems ◽  
Time System ◽  
Real Time System ◽  
Real Time Operating System ◽  
System A ◽  
External Stimuli ◽  
Time Systems

RTOS (real time operating system) can be defined as “The ability of the operating system to provide a required level of service in bounded response time.” A real time system responds in a (timely) predictable way to unpredictable external stimuli arrivals. To build a predictable system, all its components (hardware & software) should enable this requirement to be fulfilled. Traffic on a bus for example should take place in a way allowing all events to be managed within the prescribe time limit. However it should not be forgotten that a good RTOS is only is building block. Using it in a wrongly designed system may lead to a malfunctioning of the RT system. A good RTOS can be defined as one that has a bounded (predictable) behavior under all system load scenarios (simultaneous interrupts and thread execution). In RT system, each individual deadline should be met. Real-time systems are designed to control and monitor their environment. Most of these systems are using sensors to collect environment state and use actuators to change something.

Implementation and Comparative Analysis of k-means and Fuzzy c-means Clustering Algorithms for Tasks Allocation in Distributed Real Time System

2019 ◽  
Vol 10 (2) ◽  
pp. 66-86 ◽  
Author(s):  
Harendra Kumar ◽  
Isha Tyagi
Keyword(s):  
Real Time ◽  
High Performance ◽  
Distributed Processing ◽  
Clustering Algorithms ◽  
Processing System ◽  
Real Time Systems ◽  
Real Time System ◽  
Fuzzy C Means ◽  
Fuzzy C Means Clustering ◽  
Time Systems

Distributing tasks to processors in distributed real time systems is an important step for obtaining high performance. Scheduling algorithms play a vital role in achieving better performance and high throughput in heterogeneous distributed real time systems. To make the best use of the computational power available, it is essential to assign the tasks to the processor whose characteristics are most appropriate for the execution of the tasks in a distributed processing system. This study develops two algorithms for clustering the heavily-communicating tasks to reduce the inter-tasks communication costs by using k-means and fuzzy c-means clustering techniques respectively. In order to minimize the system cost and response time, an algorithm is developed for the proper allocation of formed clusters to the most suitable processor. The present algorithms are collated with problems in literature. The proposed algorithms are formulated and applied to numerous numerical examples to demonstrate their effectiveness.

scholarly journals Reducing Dynamic Power Consumption in Mixed-Critical Real-Time Systems

2020 ◽  
Vol 10 (20) ◽  
pp. 7256
Author(s):  
Ijaz Ali ◽  
Yong-Il Jo ◽  
Seonah Lee ◽  
Wan Yeon Lee ◽  
Kyong Hoon Kim
Keyword(s):  
Real Time ◽  
Energy Minimization ◽  
Real Time Systems ◽  
Real Time System ◽  
Dynamic Power ◽  
Frequency Level ◽  
Memory Power ◽  
System Frequency ◽  
Time Systems ◽  
Mixed Criticality

In this paper, we study energy minimization consumption of a mixed criticality real-time system on uni-core. Our focus is on a new scheduling scheme to decrease the frequency level in order to conserve power. Since many systems are equipped with dynamic power and frequency level memory, power can be saved by decreasing the system frequency. In this paper, we provide new dynamic energy minimization consumption in mixed-criticality real-time systems. Recent research has been done on low-criticality mode for power reduction. Thus, the proposed scheme can reduce the energy both in high-criticality and low-criticality modes. The effectiveness of our proposed scheme in energy reduction is clearly shown through simulations results.

scholarly journals Comparison of Scheduling Algorithms in The Design of Fault Tolerant Real Time Systems

2018 ◽  
Vol 7 (2.7) ◽  
pp. 618
Author(s):  
Mary Swarna Latha Gade ◽  
K Sreenivasa Ravi
Keyword(s):  
Real Time ◽  
Fault Tolerant ◽  
Scheduling Algorithms ◽  
Timing Constraints ◽  
Real Time Systems ◽  
Worst Case ◽  
Real Time System ◽  
Utilization Factor ◽  
Functional Correctness ◽  
Time Systems

Most of the real time systems have the timing constraints. The main important timing constraints of any real time systems are to meet the deadlines of its application tasks. Not only satisfying the timing constraints of any real-time system, but also the functional correctness of application needs to be guaranteed. Meeting the dead line of application is no use if it deviates from its precise output. Timing constraints of the system can be satisfied by choosing proper task scheduling algorithms and the reliability of the system can be reached by providing fault-tolerance. In this paper, various fault scheduling algorithms like fixed priority, EDF(Earliest dead line first), LLF (Least Laxity First),Rate monotonic etc have been studied and compare the parameters like Worst-case execution times, response time, task missed deadlines, Number of preemption, number of context switches, Deadlock  and processor utilization factor. 

ADDING FORM TO REAL-TIME SYSTEM SPECIFICATION AND SIMULATION

1999 ◽  
Vol 09 (05) ◽  
pp. 643-661 ◽  
Author(s):  
JI Y. LEE ◽  
KYO C. KANG ◽  
GERARD J. KIM ◽  
HYE J. KIM
Keyword(s):  
Real Time ◽  
Critical Role ◽  
Real Time Systems ◽  
System Specification ◽  
Time System ◽  
Real Time System ◽  
Interactive Behavior ◽  
Behavior Function ◽  
And Behavior ◽  
Time Systems

Specification and validation of a real-time system are often based on making simplistic predictions and assumptions about relevant behavior of the external environment and the controlled device interacting with it. However, in many cases, real-time systems physically interact with other external objects in a complex manner in a dynamically changing world and thus, their form (e.g. physical properties such as shape, mass, material, and configuration) can play a critical role in producing a correct specification and obtaining realistic simulation output. We present ASADAL/PROTO, a specification and simulation tool for real-time systems, that takes form into account in addition to the function and behavior handled by ASADAL/SIM, its predecessor. Simulation of the control system specification runs in conjunction with the environmental simulation, and the resulting interactive behavior of the controlled system is observed visually for analysis. Our vision is to incrementally model, simulate and analyze all three views (behavior, function, and form) of real-time system specification for its increased level of confidence at early prototyping stage.

scholarly journals Performance of Dynamic Queue based Minimal Deadline First Scheduling Algorithm in Multicore System Under Real Time and NonReal Time Kernel Environment

2019 ◽  
Vol 8 (11) ◽  
pp. 3263-3268
Keyword(s):  
Operating System ◽  
Real Time ◽  
Low Cost ◽  
Scheduling Algorithm ◽  
Priority Queue ◽  
Real Time Systems ◽  
Real Time System ◽  
Core System ◽  
Hard Real Time ◽  
Time Systems

Some real-time systems that need to be associated with operating system services with a hard real-time system. Since these real-time systems that need to be extremely responsive to the outside world have no simple and low-cost operating system assistance. This paper deals with the application on a Linux-based operating system of the priority-based preemptive real-time scheduling algorithm that will suffice these firm applications in real-time. Typically, the algorithms regarded for these hard real-time systems are preemptive scheduling based on priorities. Based on the priority, by meeting the deadline, this algorithm can produce a feasible schedule for the dynamic tasks to be performed on the processor. It is feasible to schedule tasks on a processor as long as preemption is permitted and tasks do not compete for resources. In this scheduling algorithm, the task in the running queue that is waiting for the execution will be placed in the priority queue that is ready to execute in the available processor. This algorithm is deployed in the Linux kernel with the patch file and the kernel is built in the multi core system to execute an application

SPECIFYING INDUSTRIAL REAL-TIME SYSTEMS WITH A TEMPORAL LOGIC FRAMEWORK

1996 ◽  
Vol 06 (01) ◽  
pp. 21-61
Author(s):  
EMANUELE CIAPESSONI ◽  
EDOARDO CORSETTI ◽  
MANLIO MIGLIORATI ◽  
ELENA RATTO ◽  
ERNANI CRIVELLI
Keyword(s):  
Real Time ◽  
Temporal Logic ◽  
Formal Method ◽  
Object Oriented ◽  
Logical Framework ◽  
Real Time Systems ◽  
Temporal Constraint ◽  
Real Time System ◽  
Metric Temporal Logic ◽  
Time Systems

This paper presents the TRIO logical framework to specify industrial real-time systems. Typical specification requirements for this kind of system are discussed and related to corresponding features of the framework. In particular, the methodological expressiveness, the validation and the temporal constraint proof capabilities are highlighted. The former is mainly dealt with by the Object Oriented paradigm, while the latter is dealt with by a formal method specification derived from Metric Temporal Logic languages. Further, this Metric Temporal Logic is extended with the ability to treat different granularities. In order to show the capabilities of the TRIO logical framework, the specification of a complex real-time system is proposed.

Synchronization-Aware Task Allocation Techniques for Preemption Control to Reduce Blocking Time in Multiprocessor Real-Time System

2020 ◽  
Vol 11 (4) ◽  
pp. 60-79
Author(s):  
Ajitesh Kumar ◽  
Sanjai Kumar Gupta
Keyword(s):  
Real Time ◽  
Task Completion ◽  
Real Time Systems ◽  
Time System ◽  
Real Time System ◽  
Priority Inversion ◽  
Context Switching ◽  
Optimal Approach ◽  
Result Analysis ◽  
Time Systems

Multiprocessor real-time systems receive a great deal of attention. For better utilization of multiprocessors in a real-time context, an optimal approach for scheduling, allocation, and synchronization is required. In this research, a novel heuristic synchronization-aware scheduling has been proposed to reduce the blocking delays in a critical section and also bound to minimize multiple priority inversion. The key idea of this technique is to assign the task set in the same processor that accesses a common shared resource and also access them for the longest period of time; thereby, the global sharing of resource transforms into local sharing. From simulation results, it was concluded that the duration of blocking overheads should be minimized up to 25% to 30% and context switching between processors also reduced up to 10% to 15%. On the basis of result analysis, schedulability, minimization of context switching, and reduced blocking time indicate that the proposed method outperforms the existing methods and does not affect the task completion time.

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