229 research outputs found
Distributed Rate Scaling in Large-Scale Service Systems
We consider a large-scale parallel-server system, where each server
independently adjusts its processing speed in a decentralized manner. The
objective is to minimize the overall cost, which comprises the average cost of
maintaining the servers' processing speeds and a non-decreasing function of the
tasks' sojourn times. The problem is compounded by the lack of knowledge of the
task arrival rate and the absence of a centralized control or communication
among the servers. We draw on ideas from stochastic approximation and present a
novel rate scaling algorithm that ensures convergence of all server processing
speeds to the globally asymptotically optimum value as the system size
increases. Apart from the algorithm design, a key contribution of our approach
lies in demonstrating how concepts from the stochastic approximation literature
can be leveraged to effectively tackle learning problems in large-scale,
distributed systems. En route, we also analyze the performance of a fully
heterogeneous parallel-server system, where each server has a distinct
processing speed, which might be of independent interest.Comment: 32 pages, 4 figure
Modelling, Dimensioning and Optimization of 5G Communication Networks, Resources and Services
This reprint aims to collect state-of-the-art research contributions that address challenges in the emerging 5G networks design, dimensioning and optimization. Designing, dimensioning and optimization of communication networks resources and services have been an inseparable part of telecom network development. The latter must convey a large volume of traffic, providing service to traffic streams with highly differentiated requirements in terms of bit-rate and service time, required quality of service and quality of experience parameters. Such a communication infrastructure presents many important challenges, such as the study of necessary multi-layer cooperation, new protocols, performance evaluation of different network parts, low layer network design, network management and security issues, and new technologies in general, which will be discussed in this book
Operational Research: methods and applications
This is the final version. Available on open access from Taylor & Francis via the DOI in this recordThroughout its history, Operational Research has evolved to include methods, models and algorithms that have been applied to a wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first summarises the up-to-date knowledge and provides an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion and used as a point of reference by a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order. The authors dedicate this paper to the 2023 Turkey/Syria earthquake victims. We sincerely hope that advances in OR will play a role towards minimising the pain and suffering caused by this and future catastrophes
Operational research:methods and applications
Throughout its history, Operational Research has evolved to include a variety of methods, models and algorithms that have been applied to a diverse and wide range of contexts. This encyclopedic article consists of two main sections: methods and applications. The first aims to summarise the up-to-date knowledge and provide an overview of the state-of-the-art methods and key developments in the various subdomains of the field. The second offers a wide-ranging list of areas where Operational Research has been applied. The article is meant to be read in a nonlinear fashion. It should be used as a point of reference or first-port-of-call for a diverse pool of readers: academics, researchers, students, and practitioners. The entries within the methods and applications sections are presented in alphabetical order
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