Download or read book Robust Scheduling for Queueing Networks written by Ramtin Pedarsani and published by . This book was released on 2015 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt: Queueing networks are used to model complicated processing environments such as data centers, call centers, transportation networks, health systems, etc. A queueing network consists of multiple interconnected queues with some routing structure, and a set of servers that have different and possibly overlapping capabilities in processing tasks (jobs) of different queues. One of the most important challenges in designing processing systems is to come up with a low-complexity and efficient scheduling policy. In this thesis, we consider the problem of robust scheduling for various types of processing networks. We call a policy robust if it does not depend on system parameters such as arrival and service rates. A major challenge in designing efficient scheduling policies for new large-scale processing networks is the lack of reliable estimates of system parameters; thus, designing a robust scheduling policy is of great practical interest. We develop a novel methodology for designing robust scheduling policies for queueing networks. The key idea of our design is to use the queue-length changes information to learn the right allocation of service resources to different tasks by stochastic gradient projection method. Our scheduling policy is oblivious to the knowledge of arrival rates and service rates of tasks in the network. Further, we propose a new fork-join processing network for scheduling jobs that are represented as directed acyclic graphs. We apply our robust scheduling policy to this fork-join network, and prove rate stability of the network under some mild assumptions. Next, we consider the stability of open multiclass queueing networks under longest-queue (LQ) scheduling. LQ scheduling is of great practical interest since (a) it requires only local decisions per group of queues; (b) the policy is robust to knowledge of arrival rates, service rates and routing probabilities of the network. Throughput-optimality of LQ scheduling policy for open multiclass queueing network is still an open problem. We resolve the open problem for a special case of multiclass queueing networks with two servers that can each process two queues, and show that LQ is indeed throughput-optimal. Finally, we consider transportation networks that can be well modeled by queueing networks. We abstractly model a network of signalized intersections regulated by fixed-time controls as a deterministic queueing network with periodic arrival and service rates. This system is characterized by a delay-differential equation. We show that there exists a unique periodic trajectory of queue-lengths, and every trajectory or solution of the system converges to this periodic trajectory, independent of the initial conditions.
Download or read book Robust Fluid Control of Multiclass Queueing Networks written by Hua Su (S.M.) and published by . This book was released on 2006 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis applies recent advances in the field of robust optimization to the optimal control of multiclass queueing networks. We develop models that take into account the uncertainty of interarrival and service time in multiclass queueing network problems without assuming a specific probability distribution, while remaining highly tractable and providing insight into the corresponding optimal control policy. Our approach also allows us to adjust the level of robustness of the solution to trade off performance and protection against uncertainty. We apply robust optimization to both open and closed queueing networks. For open queueing networks, we study control problems that involve sequencing, routing and input control decision, and optimize the total holding cost. For closed queueing networks, we focus on the sequencing problem and optimize the throughput. We compare the robust solutions to those derived by fluid control, dynamic programming and stochastic input control. We show that the robust control policy leads to better performance. Robust optimization emerges as a promising methodology to address a wide range of multiclass queueing networks subject to uncertainty, as it leads to representations of randomness that make few assumptions on the underlying probabilities. It also remains numerically tractable, and provides theoretical insights into the structure of the optimal control policy.
Download or read book Optimal and Robust Scheduling for Networked Control Systems written by Stefano Longo and published by CRC Press. This book was released on 2018-09-03 with total page 277 pages. Available in PDF, EPUB and Kindle. Book excerpt: Optimal and Robust Scheduling for Networked Control Systems tackles the problem of integrating system components—controllers, sensors, and actuators—in a networked control system. It is common practice in industry to solve such problems heuristically, because the few theoretical results available are not comprehensive and cannot be readily applied by practitioners. This book offers a solution to the deterministic scheduling problem that is based on rigorous control theoretical tools but also addresses practical implementation issues. Helping to bridge the gap between control theory and computer science, it suggests that the consideration of communication constraints at the design stage will significantly improve the performance of the control system. Technical Results, Design Techniques, and Practical Applications The book brings together well-known measures for robust performance as well as fast stochastic algorithms to assist designers in selecting the best network configuration and guaranteeing the speed of offline optimization. The authors propose a unifying framework for modelling NCSs with time-triggered communication and present technical results. They also introduce design techniques, including for the codesign of a controller and communication sequence and for the robust design of a communication sequence for a given controller. Case studies explore the use of the FlexRay TDMA and time-triggered control area network (CAN) protocols in an automotive control system. Practical Solutions to Your Time-Triggered Communication Problems This unique book develops ready-to-use engineering tools for large-scale control system integration with a focus on robustness and performance. It emphasizes techniques that are directly applicable to time-triggered communication problems in the automotive industry and in avionics, robotics, and automated manufacturing.
Download or read book Flexibility and Robustness in Scheduling written by Jean-Charles Billaut and published by John Wiley & Sons. This book was released on 2013-03-01 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scheduling is a broad research area and scheduling problems arise from several application domains (production systems, logistic, computer science, etc.). Solving scheduling problems requires tools of combinatorial optimization, exact or approximated algorithms. Flexibility is at the frontier between predictive deterministic approaches and reactive or "on-line" approaches. The purpose of flexibility is to provide one or more solutions adapted to the context of the application in order to provide the ideal solution. This book focuses on the integration of flexibility and robustness considerations in the study of scheduling problems. After considering both flexibility and robustness, it then covers various scheduling problems, treated with an emphasis on flexibility or robustness, or both.
Download or read book Scheduling and Control of Queueing Networks written by Gideon Weiss and published by Cambridge University Press. This book was released on 2021-10-14 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Applications of queueing network models have multiplied in the last generation, including scheduling of large manufacturing systems, control of patient flow in health systems, load balancing in cloud computing, and matching in ride sharing. These problems are too large and complex for exact solution, but their scale allows approximation. This book is the first comprehensive treatment of fluid scaling, diffusion scaling, and many-server scaling in a single text presented at a level suitable for graduate students. Fluid scaling is used to verify stability, in particular treating max weight policies, and to study optimal control of transient queueing networks. Diffusion scaling is used to control systems in balanced heavy traffic, by solving for optimal scheduling, admission control, and routing in Brownian networks. Many-server scaling is studied in the quality and efficiency driven Halfin–Whitt regime and applied to load balancing in the supermarket model and to bipartite matching in ride-sharing applications.
Download or read book Queueing Networks written by Richard J. Boucherie and published by Springer Science & Business Media. This book was released on 2010-11-25 with total page 814 pages. Available in PDF, EPUB and Kindle. Book excerpt: This handbook aims to highlight fundamental, methodological and computational aspects of networks of queues to provide insights and to unify results that can be applied in a more general manner. The handbook is organized into five parts: Part 1 considers exact analytical results such as of product form type. Topics include characterization of product forms by physical balance concepts and simple traffic flow equations, classes of service and queue disciplines that allow a product form, a unified description of product forms for discrete time queueing networks, insights for insensitivity, and aggregation and decomposition results that allow sub networks to be aggregated into single nodes to reduce computational burden. Part 2 looks at monotonicity and comparison results such as for computational simplification by either of two approaches: stochastic monotonicity and ordering results based on the ordering of the process generators, and comparison results and explicit error bounds based on an underlying Markov reward structure leading to ordering of expectations of performance measures. Part 3 presents diffusion and fluid results. It specifically looks at the fluid regime and the diffusion regime. Both of these are illustrated through fluid limits for the analysis of system stability, diffusion approximations for multi-server systems, and a system fed by Gaussian traffic. Part 4 illustrates computational and approximate results through the classical MVA (mean value analysis) and QNA (queueing network analyzer) for computing mean and variance of performance measures such as queue lengths and sojourn times; numerical approximation of response time distributions; and approximate decomposition results for large open queueing networks. spanPart 5 enlightens selected applications as spanloss networks originating from circuit switched telecommunications applications, capacity sharing originating from packet switching in data networks, and a hospital application that is of growing present day interest. spanThe book shows that spanthe intertwined progress of theory and practicespan will remain to be most intriguing and will continue to be the basis of further developments in queueing networks.
Download or read book Applications of Robust Optimization to Queueing and Inventory Systems written by Alexander Anatolyevich Rikun and published by . This book was released on 2011 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis investigates the application of robust optimization in the performance analysis of queueing and inventory systems. In the first part of the thesis, we propose a new approach for performance analysis of queueing systems based on robust optimization. We first derive explicit upper bounds on performance for tandem single class, multiclass single server, and single class multi-server queueing systems by solving appropriate robust optimization problems. We then show that these bounds derived by solving deterministic optimization problems translate to upper bounds on the expected steady-state performance for a variety of widely used performance measures such as waiting times and queue lengths. Additionally, these explicit bounds agree qualitatively with known results. In the second part of the thesis, we propose methods to compute (s,S) policies in supply chain networks using robust and stochastic optimization and compare their performance. Our algorithms handle general uncertainty sets, arbitrary network topologies, and flexible cost functions including the presence of fixed costs. The algorithms exhibit empirically practical running times. We contrast the performance of robust and stochastic (s,S) policies in a numerical study, and we find that the robust policy is comparable to the average performance of the stochastic policy, but has a considerably lower standard deviation across a variety of networks and realized demand distributions. Additionally, we identify regimes when the robust policy exhibits particular strengths even in average performance and tail behavior as compared with the stochastic policy.
Download or read book Scheduling Multiclass Queueing Networks and Job Shops Using Fluid and Semidefinite Relaxations written by Jayachandran Sethuraman and published by . This book was released on 1999 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Robust and Online Large Scale Optimization written by Ravindra K. Ahuja and published by Springer Science & Business Media. This book was released on 2009-10-26 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scheduled transportation networks give rise to very complex and large-scale networkoptimization problems requiring innovative solution techniques and ideas from mathematical optimization and theoretical computer science. Examples of scheduled transportation include bus, ferry, airline, and railway networks, with the latter being a prime application domain that provides a fair amount of the most complex and largest instances of such optimization problems. Scheduled transport optimization deals with planning and scheduling problems over several time horizons, and substantial progress has been made for strategic planning and scheduling problems in all transportation domains. This state-of-the-art survey presents the outcome of an open call for contributions asking for either research papers or state-of-the-art survey articles. We received 24 submissions that underwent two rounds of the standard peer-review process, out of which 18 were finally accepted for publication. The volume is organized in four parts: Robustness and Recoverability, Robust Timetabling and Route Planning, Robust Planning Under Scarce Resources, and Online Planning: Delay and Disruption Management.
Download or read book A Nonlinear Queueing based Planning and Scheduling Framework for Multi product Supply Networks written by Rodrigo Caliz Ospino and published by . This book was released on 2010 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research work presents a hierarchical nonlinear optimization-based framework for planning and scheduling of supply networks modeled as multi-class stochastic queueing networks. More precisely, the framework has two decision layers. At the top level a tactical processing plan is designed. This is accomplished by means of a nonlinear optimal control formulation, along with suitable solution algorithms, to compute on a rolling-horizon basis a tactical processing plan which yields the lowest cost expected-value inventory trajectory. In doing so, raw materials, inventory and demand mismatching costs are considered. As the main outcome, a target inventory trajectory is obtained for each inventory buer in the network at all times within a rolling planning time window. The bottom layer in turn deals with a distributed scheduling framework to best track the inventory targets generated by the tactical processing plan. In this regard, a processing schedule is generated for each server in the system so that sequence-dependent and inventory holding costs are minimized for each server within the current planning time window. Uncertainty in the inventory accumulation and depletion processes as well as network interrelations is accounted for by means of a robust optimization formulation. Several numerical examples are presented in order to illustrate the framework mechanics as well as the algorithmic issues inherent to the dierent optimization steps performed on a hierarchical basis. The planning framework can also be adapted to standard Enterprise Resource Systems (ERPs) to best support the planning and scheduling functions on a regular basis.
Download or read book Fundamentals of Queueing Networks written by Hong Chen and published by Springer. This book was released on 2010-12-04 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: This accessible book aims to collect in a single volume the essentials of stochastic networks. Stochastic networks have become widely used as a basic model of many physical systems in a diverse range of fields. Written by leading authors in the field, this book is meant to be used as a reference or supplementary reading by practitioners in operations research, computer systems, communications networks, production planning, and logistics.
Download or read book Stability and Scheduling in Multiclass Queueing Networks written by Cédric Westphal and published by . This book was released on 2000 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamic Scheduling of Queueing Networks written by Jihong Ou and published by . This book was released on 1991 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Quality Reliability Security and Robustness in Heterogeneous Networks written by Xi Zhang and published by Springer. This book was released on 2012-04-23 with total page 650 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the thoroughly refereed post-conference proceedings of the 7th International Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QShine 2010. The 37 revised full papers presented along with 7 papers from the allocated Dedicated Short Range Communications Workshop, DSRC 2010, were carefully selected from numerous submissions. Conference papers are organized into 9 technical sessions, covering the topics of cognitive radio networks, security, resource allocation, wireless protocols and algorithms, advanced networking systems, sensor networks, scheduling and optimization, routing protocols, multimedia and stream processing. Workshop papers are organized into two sessions: DSRC networks and DSRC security.
Download or read book Robustness Analysis in Decision Aiding Optimization and Analytics written by Michael Doumpos and published by Springer. This book was released on 2016-07-12 with total page 337 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a broad coverage of the recent advances in robustness analysis in decision aiding, optimization, and analytics. It offers a comprehensive illustration of the challenges that robustness raises in different operations research and management science (OR/MS) contexts and the methodologies proposed from multiple perspectives. Aside from covering recent methodological developments, this volume also features applications of robust techniques in engineering and management, thus illustrating the robustness issues raised in real-world problems and their resolution within advances in OR/MS methodologies. Robustness analysis seeks to address issues by promoting solutions, which are acceptable under a wide set of hypotheses, assumptions and estimates. In OR/MS, robustness has been mostly viewed in the context of optimization under uncertainty. Several scholars, however, have emphasized the multiple facets of robustness analysis in a broader OR/MS perspective that goes beyond the traditional framework, seeking to cover the decision support nature of OR/MS methodologies as well. As new challenges emerge in a “big-data'” era, where the information volume, speed of flow, and complexity increase rapidly, and analytics play a fundamental role for strategic and operational decision-making at a global level, robustness issues such as the ones covered in this book become more relevant than ever for providing sound decision support through more powerful analytic tools.
Download or read book Quality Reliability Security and Robustness in Heterogeneous Networks written by Jong-Hyouk Lee and published by Springer. This book was released on 2017-08-08 with total page 501 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refereed conference proceedings of the 12th EAI International Conference on Quality, Reliability, Security and Robustness in Heterogeneous Networks, QShine 2016, held in Seoul, South Korea, in July 2016. The 27 full papers, 5 short papers and 18 workshop papers were selected from 85 submissions. The papers are organized thematically in tracks, starting with network security, followed by QoS, reliability and modeling, wireless and mobile networks. In addition the papers of two workshops are included: International Workshop on 5G Communication Architecture and Technology (5G-CAT 2016), and the 2nd International Workshop on Sensor Networks and Cloud Computing (SNCC 2016).
Download or read book Routing and Scheduling in Queueing Networks written by Rema Hariharan and published by . This book was released on 1991 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
