Download or read book Feedback based Task Scheduling in Real time Systems written by Suzhen Lin and published by . This book was released on 2005 with total page 206 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real-time computing is an enabling technology for many current and next generation applications. One of the key components of real-time systems is the scheduling of tasks, the objective of which is to meet task deadlines predictably. Traditional real-time task scheduling paradigms perform well in static or dynamic systems in which the workload can be accurately modeled. Unfortunately, in many complex applications, unpredictable dynamic factors exist due to which precise workload characterization is difficult. In recent years, feedback control techniques have been successfully applied to address the issue of unpredictable workload in computing systems. In this dissertation, we develop feedback-based algorithms and analysis for some important dynamic scheduling problems in real-time systems. First, we address the problem of selective herbicide spraying in precision farming application. The goal is to achieve low weed miss ratio and high CPU utilization. We carry out system identification, vehicle modeling and controller design. In our design, the requested CPU utilization is fed back and the vehicle speed is controlled. The system model is verified and performance evaluation is carried out through simulation studies. The second problem is task scheduling based on (m, k)-firm deadline constraints in real-time systems. The proposed solution feeds back the current dynamic failure rate (DFR) and adjusts the task's QoS based on DFR on-line. We also propose a novel fairness metric to evaluate the fairness in QoS among tasks achieved by the scheduler. The simulation results show that the QoS of tasks can be improved significantly while keeping the DFR below a certain threshold. The third problem is combined task scheduling with fault tolerance in real-time systems. In our model, the rate monotonic scheduling algorithm and deferrable server algorithm are used to schedule periodic and aperiodic tasks, respectively. By using feedback control technique, we adjust the capacity of the deferrable servers based on the failure rate of the periodic tasks. The performances of the systems are evaluated through simulation studies. The last problem is task scheduling in distributed real-time systems. We propose a double-loop scheme to keep the deadline miss ratio close to the set point and maximize the CPU utilization, and analyze the stability of the system in Z-domain. We also propose a global scheduling method to achieve load balancing by using a suitable load index. The performances of the systems are evaluated through simulation studies. The feedback-based solutions proposed in this dissertation are based on the principle of controlling the trade-off between deadline miss ratio and resource utilization. This idea can be adapted not only to other scheduling problems in real-time systems, but also to scheduling problems in non-real-time systems.

Download or read book Deadline Scheduling for Real Time Systems written by John A. Stankovic and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 280 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many real-time systems rely on static scheduling algorithms. This includes cyclic scheduling, rate monotonic scheduling and fixed schedules created by off-line scheduling techniques such as dynamic programming, heuristic search, and simulated annealing. However, for many real-time systems, static scheduling algorithms are quite restrictive and inflexible. For example, highly automated agile manufacturing, command, control and communications, and distributed real-time multimedia applications all operate over long lifetimes and in highly non-deterministic environments. Dynamic real-time scheduling algorithms are more appropriate for these systems and are used in such systems. Many of these algorithms are based on earliest deadline first (EDF) policies. There exists a wealth of literature on EDF-based scheduling with many extensions to deal with sophisticated issues such as precedence constraints, resource requirements, system overload, multi-processors, and distributed systems. Deadline Scheduling for Real-Time Systems: EDF and Related Algorithms aims at collecting a significant body of knowledge on EDF scheduling for real-time systems, but it does not try to be all-inclusive (the literature is too extensive). The book primarily presents the algorithms and associated analysis, but guidelines, rules, and implementation considerations are also discussed, especially for the more complicated situations where mathematical analysis is difficult. In general, it is very difficult to codify and taxonomize scheduling knowledge because there are many performance metrics, task characteristics, and system configurations. Also, adding to the complexity is the fact that a variety of algorithms have been designed for different combinations of these considerations. In spite of the recent advances there are still gaps in the solution space and there is a need to integrate the available solutions. For example, a list of issues to consider includes: preemptive versus non-preemptive tasks, uni-processors versus multi-processors, using EDF at dispatch time versus EDF-based planning, precedence constraints among tasks, resource constraints, periodic versus aperiodic versus sporadic tasks, scheduling during overload, fault tolerance requirements, and providing guarantees and levels of guarantees (meeting quality of service requirements). Deadline Scheduling for Real-Time Systems: EDF and Related Algorithms should be of interest to researchers, real-time system designers, and instructors and students, either as a focussed course on deadline-based scheduling for real-time systems, or, more likely, as part of a more general course on real-time computing. The book serves as an invaluable reference in this fast-moving field.

Download or read book Resource Management in Real time Systems and Networks written by C. Siva Ram Murthy and published by MIT Press. This book was released on 2001 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the concepts and state-of-the-art research developments of resource management in real-time systems and networks. Real-time systems and networks are of increasing importance in many applications, including automated factories, telecommunication systems, defense systems, and space systems. This book introduces the concepts and state-of-the-art research developments of resource management in real-time systems and networks. Unlike other texts in the field, it covers the entire spectrum of issues in resource management, including task scheduling in uniprocessor real-time systems; task scheduling, fault-tolerant task scheduling, and resource reclaiming in multiprocessor real-time systems; conventional task scheduling and object-based task scheduling in distributed real-time systems; message scheduling; QoS routing; dependable communication; multicast communication; and medium access protocols in real-time networks. It provides algorithmic treatments for all of the issues addressed, highlighting the intuition behind each algorithm and giving examples. The book also includes two chapters of case studies.

Download or read book Real time Systems Scheduling 2 written by Maryline Chetto and published by John Wiley & Sons. This book was released on 2014-09-10 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt: Real-time systems are used in a wide range of applications, including control, sensing, multimedia, etc. Scheduling is a central problem for these computing/communication systems since it is responsible for software execution in a timely manner. This book, the second of two volumes on the subject, brings together knowledge on specific topics and discusses the recent advances for some of them. It addresses foundations as well as the latest advances and findings in real-time scheduling, giving comprehensive references to important papers, but the chapters are short and not overloaded with confusing details. Coverage includes scheduling approaches for networks and for energy autonomous systems. Other sophisticated issues, such as feedback control scheduling and probabilistic scheduling, are also addressed. This book can serve as a textbook for courses on the topic in bachelor's degrees and in more advanced master's degree programs. It also provides a reference for computer scientists and engineers involved in the design or the development of Cyber-Physical Systems which require up-to-date real-time scheduling solutions.

Download or read book Control and Scheduling Codesign written by Feng Xia and published by Springer Science & Business Media. This book was released on 2008-10-11 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: With emphasis on flexible resource management in networked and embedded real-time control systems operating in dynamic environments with uncertainty, this book is devoted to the integration of control with computing and communication. It covers the authors' recent and original research results within a unified framework of feedback scheduling. This useful reference also includes rich example problems, case studies, and extensive references to the literature.

Download or read book Introducing Blockchain Applications written by Joseph Thachil George and published by Apress. This book was released on 2021-12-01 with total page 453 pages. Available in PDF, EPUB and Kindle. Book excerpt: Deepen your understanding of blockchain technology and develop your own blockchain applications. This book provides a thorough review of distribution-based systems on blockchain technology, starting from the fundamental concepts that underlie it, all the way through the implementation of a blockchain network for business purposes. Author Joseph Thachil George begins by introducing you to blockchain and some basic concepts of technology, including distributed systems, systems of systems, cyber-physical systems, the Byzantine Consensus, the CAP theorem, and cryptographic techniques. Next, he analyzes the structure of blocks and smart contracts and the mother of all blockchain platforms, Bitcoin. That sets the stage for an examination of transaction structure, validation, and flow, from creation to registration in the ledger and structure of the blocks, the Nakamoto consensus, and finally forks. From there, you’ll experience a deep dive into Ethereum; including the concepts of Gas and Message, smart contracts and the Ethereum virtual machine. From there, you’ll learn about the Ethereum consensus protocol, Ethereum Casper, and the Ethereum Proof-of-Stake algorithm. You’ll then see how blockchain can be connected to a distributed system, followed by a demonstration of how you can model a distributed system using Blockly4SoS and Kilobots. The concluding chapters offer a practical example that combines distributed systems with blockchain technology. After reading this book, you will understand how to implement blockchain technology in a distributed system and be able to leverage this knowledge in your own projects. What You Will Learn Learn the concept of blockchains by way of a practical example Grasp the connection between distributed systems and blockchain technology Learn the design of blockchain with hyperledger fabric Learn the design of cyber-physical systems in a distributed environment Who Is This Book For Developers who are enthusiastic about the design and implementation of distributed systems.

Download or read book Real time Scheduling of Robotic and Control Systems with Task Dependencies written by Peijiang Yuan and published by . This book was released on 2005 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis considers the real-time scheduling issues for control based applications with both timing constraints and precedence constraints in open environments. The schedulability issues of the control based real-time applications is also addressed. In this thesis, we present the real-time scheduling problem with two main goals. Our first goal is to develop a feedback scheduling algorithm to handle timing and precedence constraints in real-time environments. Our second goal is to address the schedulability issues of the control based real-time applications, where a system that cannot be scheduled with the traditional real-time scheduling algorithms can be scheduled with our proposed method. A task-oriented scheduling algorithm (TOA) and a multi task-oriented algorithm are addressed which can satisfy both the timing constraints and the task interdependencies between/among tasks. An experimental study is conducted to assess the performance of the presented algorithms and compares them to other existing real-time scheduling algorithms. An integrated feedback scheduling model of real-time control applications is given and a formalized framework is addressed within which scheduling algorithms can be chosen based on timing constraints and desired quality of service. We develop a multi-robot scheduling architecture, an offline scheduling algorithm, and an online scheduling algorithm that provide performance guarantees in terms of deadline miss ratio and CPU utilization in face of unpredictable task arrivals and execution time variations due to network latency and jitters. These scheduling algorithms are analytically designed and tuned with feedback control theory. For a given set of tasks with bounded time periods, tasks that are not schedulable of their given frequencies may be schedulable with the proposed feedback scheduling method.

Download or read book Hard Real Time Computing Systems written by Giorgio C Buttazzo and published by Springer Science & Business Media. This book was released on 2011-09-10 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This updated edition offers an indispensable exposition on real-time computing, with particular emphasis on predictable scheduling algorithms. It introduces the fundamental concepts of real-time computing, demonstrates the most significant results in the field, and provides the essential methodologies for designing predictable computing systems used to support time-critical control applications. Along with an in-depth guide to the available approaches for the implementation and analysis of real-time applications, this revised edition contains a close examination of recent developments in real-time systems, including limited preemptive scheduling, resource reservation techniques, overload handling algorithms, and adaptive scheduling techniques. This volume serves as a fundamental advanced-level textbook. Each chapter provides basic concepts, which are followed by algorithms, illustrated with concrete examples, figures and tables. Exercises and solutions are provided to enhance self-study, making this an excellent reference for those interested in real-time computing for designing and/or developing predictable control applications.

Download or read book Real Time Systems Architecture Scheduling and Application written by Seyed Morteza Babamir and published by BoD – Books on Demand. This book was released on 2012-04-11 with total page 351 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a rich text for introducing diverse aspects of real-time systems including architecture, specification and verification, scheduling and real world applications. It is useful for advanced graduate students and researchers in a wide range of disciplines impacted by embedded computing and software. Since the book covers the most recent advances in real-time systems and communications networks, it serves as a vehicle for technology transition within the real-time systems community of systems architects, designers, technologists, and system analysts. Real-time applications are used in daily operations, such as engine and break mechanisms in cars, traffic light and air-traffic control and heart beat and blood pressure monitoring. This book includes 15 chapters arranged in 4 sections, Architecture (chapters 1-4), Specification and Verification (chapters 5-6), Scheduling (chapters 7-9) and Real word applications (chapters 10-15).

Download or read book Hybrid Systems Computation and Control written by Alberto Bemporad and published by Springer. This book was released on 2007-05-31 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed proceedings of the 10th International Conference on Hybrid Systems: Computation and Control, HSCC 2007, held in Pisa, Italy in April 2007. Among the topics addressed are models of heterogeneous systems, computability and complexity issues, real-time computing and control, embedded and resource-aware control, control and estimation over wireless networks, and programming languages support and implementation.

Download or read book A Practical Approach to Real time Systems written by Phillip A. Laplante and published by Institute of Electrical & Electronics Engineers(IEEE). This book was released on 2000 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: Under the same cover, this volume offers both modern and classic papers focusing on real-time systems design and analysis. Rather than focusing in theoretical observations of real-time systems, it is intended for the practical professional who is building real real-time systems. The editor, himself the author of a course on real-time systems, has selected articles to provide a deep exploration of issues raised in his other works. In particular, emphasis is placed on applying practical, but theoretically sound approaches in software engineering rate-monotonic design and analysis, testing and architecting systems for real-time applications.

Download or read book Multiprocessor Scheduling for Real Time Systems written by Sanjoy Baruah and published by Springer. This book was released on 2015-01-02 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a comprehensive overview of both theoretical and pragmatic aspects of resource-allocation and scheduling in multiprocessor and multicore hard-real-time systems. The authors derive new, abstract models of real-time tasks that capture accurately the salient features of real application systems that are to be implemented on multiprocessor platforms, and identify rules for mapping application systems onto the most appropriate models. New run-time multiprocessor scheduling algorithms are presented, which are demonstrably better than those currently used, both in terms of run-time efficiency and tractability of off-line analysis. Readers will benefit from a new design and analysis framework for multiprocessor real-time systems, which will translate into a significantly enhanced ability to provide formally verified, safety-critical real-time systems at a significantly lower cost.

Download or read book Operating Systems written by Remzi H. Arpaci-Dusseau and published by Createspace Independent Publishing Platform. This book was released on 2018-09 with total page 714 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book is organized around three concepts fundamental to OS construction: virtualization (of CPU and memory), concurrency (locks and condition variables), and persistence (disks, RAIDS, and file systems"--Back cover.

Download or read book Dynamic Resource Allocation in Embedded High Performance and Cloud Computing written by Leando Soares Indrusiak and published by CRC Press. This book was released on 2022-09-01 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: The availability of many-core computing platforms enables a wide variety of technical solutions for systems across the embedded, high-performance and cloud computing domains. However, large scale manycore systems are notoriously hard to optimise. Choices regarding resource allocation alone can account for wide variability in timeliness and energy dissipation (up to several orders of magnitude). Dynamic Resource Allocation in Embedded, High-Performance and Cloud Computing covers dynamic resource allocation heuristics for manycore systems, aiming to provide appropriate guarantees on performance and energy efficiency. It addresses different types of systems, aiming to harmonise the approaches to dynamic allocation across the complete spectrum between systems with little flexibility and strict real-time guarantees all the way to highly dynamic systems with soft performance requirements. Technical topics presented in the book include: • Load and Resource Models• Admission Control• Feedback-based Allocation and Optimisation• Search-based Allocation Heuristics• Distributed Allocation based on Swarm Intelligence• Value-Based AllocationEach of the topics is illustrated with examples based on realistic computational platforms such as Network-on-Chip manycore processors, grids and private cloud environments.

Download or read book Real Time Systems Symposium written by American Society of Mechanical Engineers and published by . This book was released on 2004 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling Manufacturing Systems written by Paolo Brandimarte and published by Springer Science & Business Media. This book was released on 1999-03-29 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced modeling techniques are a necessary tool in order to design and manage manufacturing systems effectively. This book contains a set of tutorial chapters on topics ranging from aggregate production planning to real time control, including predictive and reactive scheduling, flow management in assembly systems, simulation of robotic cells, design of manufacturing systems under uncertainty and a historical perspective on production management philosophies. The book will be of interest both to researchers and practitioners, including graduate students in Manufacturing Engineering and Operations Research.

Download or read book Scheduling and Reconfiguration of Real Time Systems written by Xi Wang and published by Springer Nature. This book was released on 2023-12-17 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a methodology for the real-time scheduling problems of real-time systems (RTS) from the viewpoint of control theory. Generally, any system can be viewed as an RTS if it performs real-time application functions and behaves correctly depending on given logical activities and satisfying specified deadlines for the activities. This monograph provides broad views and detailed introductions to supervisory control theory (SCT) and its application in real-time scheduling and reconfiguration. Based on three popular SCT modelling frameworks, discrete-event system (DES), timed DES (TDES), and state-tree structures (STS), the authors provide RTS modelling frameworks; thereafter, SCT is used to find their safe execution sequences. As the main contribution, we use (untimed) DES events to represent the execution and preemption of each individual RTS task. This modelling formalism brings the possibilities to model the preemptions of tasks’ executions. Furthermore, in some cases, priorities cannot be assigned to real-time tasks. In order to solve this problem, a matrix-based priority-free conditional-preemption (PFCP) relation is provided, which generalizes fixed-priority (FP) RTS scheduling. As a natural extension, a generalized modular modelling framework is presented to model the task parameters instead of the global real-time task. The modular models are taken to be generic entities, which also considers the exact execution time of real-time tasks. STS are undoubtedly recognized as a computationally efficient SCT framework which manages the state explosion problem significantly. Hence, building on the (untimed) modular RTS models, a novel STS-based RTS modeling framework is formulated, by assigning dynamic priorities as specified optimality criteria, which can be utilized to model sporadic RTS processing both sporadic and (multi-period) periodic tasks, providing a small set of the safe execution sequences which rank at the top.