Agassi Melikov

Bio: Agassi Melikov is an academic researcher from Azerbaijan National Academy of Sciences. The author has contributed to research in topics: Queueing theory & Queue. The author has an hindex of 10, co-authored 44 publications receiving 269 citations. Previous affiliations of Agassi Melikov include ANAS.

Performance Analysis and Optimization of Multi-Traffic on Communication Networks

Abstract: Promptly growing demand for telecommunication services and information interchange has led to the fact that communication became one of the most dynamical branches of an infrastructure of a modern society. The book introduces to the bases of classical MDP theory; problems of a finding optimal in models are investigated and various problems of improvement of characteristics of traditional and multimedia wireless communication networks are considered together with both classical and new methods of theory MDP which allow defining optimal strategy of access in teletraffic systems. The book will be useful to specialists in the field of telecommunication systems and also to students and post-graduate students of corresponding specialties.

Stock optimization in transportation/storage systems

Abstract: Optimal stock reorder policies are determined for transportation/storage systems with queueing of user requests. Exact and approximate solution methods are proposed.

Equilibrium customer behavior in the M/M/1 retrial queue with working vacations and a constant retrial rate

Abstract: In this paper, we investigate the M/M/1 retrial queue with working vacations and a constant retrial rate. In the queue, customers decide about the entry based on the information upon their arrival instants. Scenarios regarding the availability of information (i.e., the server is occupied or not, and the server is on the vacation or not) for customers are compared. We derive the closed form solution for the stationary probabilities of the queue. Social optimizing and Nash equilibrium strategies for joining the system are investigated. Based on numerical results, the social benefit rate is best when customers know all information about the server.

Fundamentals of Queueing Theory

Abstract: Praise for the Third Edition: "This is one of the best books available. Its excellent organizational structure allows quick reference to specific models and its clear presentation . . . solidifies the understanding of the concepts being presented."IIE Transactions on Operations EngineeringThoroughly revised and expanded to reflect the latest developments in the field, Fundamentals of Queueing Theory, Fourth Edition continues to present the basic statistical principles that are necessary to analyze the probabilistic nature of queues. Rather than presenting a narrow focus on the subject, this update illustrates the wide-reaching, fundamental concepts in queueing theory and its applications to diverse areas such as computer science, engineering, business, and operations research.This update takes a numerical approach to understanding and making probable estimations relating to queues, with a comprehensive outline of simple and more advanced queueing models. Newly featured topics of the Fourth Edition include:Retrial queuesApproximations for queueing networksNumerical inversion of transformsDetermining the appropriate number of servers to balance quality and cost of serviceEach chapter provides a self-contained presentation of key concepts and formulae, allowing readers to work with each section independently, while a summary table at the end of the book outlines the types of queues that have been discussed and their results. In addition, two new appendices have been added, discussing transforms and generating functions as well as the fundamentals of differential and difference equations. New examples are now included along with problems that incorporate QtsPlus software, which is freely available via the book's related Web site.With its accessible style and wealth of real-world examples, Fundamentals of Queueing Theory, Fourth Edition is an ideal book for courses on queueing theory at the upper-undergraduate and graduate levels. It is also a valuable resource for researchers and practitioners who analyze congestion in the fields of telecommunications, transportation, aviation, and management science.

Packet Dropping Policies for ATM and IP Networks(EXTENDED ABSTRACT OF THE IEEE COMMUNICATIONS SURVEYS)

Abstract: Selective packet dropping policies have been used to reduce congestion and transmission of traffic that would inevitably be retransmitted. For data applications using best-effort services, packet dropping policies (PDPs) are congestion management mechanisms implemented at each intermediate node that decide, reactively or proactively, to drop packets to reduce congestion and free up precious buffer space. While the primary goal of PDPs is to avoid or combat congestion, the individual PDP designs can significantly affect application throughput, network utilization, performance fairness, and synchronization problems with multiple transmission control protocol (TCP) connections. Scalability and simplicity are also important design issues. This article surveys the most important selective packet dropping policies that have been designed for best-effort traffic in ATM and IP networks, providing a comprehensive comparison between the different mechanisms.

Hexagonal vs Circular Cell Shape: A Comparative Analysis and Evaluation of the Two Popular Modeling Approximations

Abstract: Recent years have witnessed an explosion in wireless communications. In the last decades, the development of wireless communication systems and networks is taking us from a world where communications were mostly carried over PSTN, packet-switched and high speed LAN networks to one where the wireless transmission dominates. Nowadays, high data rates carry multimedia communications, real-time services for delay-sensitive applications are added and networks are asked to deal with a traffic mix of voice, data and video. Next generation mobile systems will further include a variety of heterogeneous access technologies, support multimedia applications and provide end-to-end IP connectivity (Bolton et al., 2007; Xylomenos et al., 2008; Demestichas et al., 2010). Undoubtedly, new possibilities are created for both telcos and users and important design and traffic issues emerge. This revolution has spurred scientists toward the development of reliable and computationally efficient models for evaluating the performance of wireless networks. A crucial parameter in the modeling of a cellular communication system is the shape of the cells. In real life, cells are irregular and complex shapes influenced by terrain features and artificial structures. However, for the sake of conceptual and computational simplicity, we often adopt approximate approaches for their design and modeling. In the published literature, cells are usually assumed hexagons or circles. The hexagonal approximation is frequently employed in planning and analysis of wireless networks due to its flexibility and convenience (Jan et al., 2004; Goldsmith, 2005; Pirinen, 2006; Chan & Liew, 2007; Hoymann et al., 2007; Baltzis, 2008, 2010a; Choi & You, 2008; Dou et al., 2008; Xiao et al., 2008; Baltzis & Sahalos, 2010). However, since this geometry is only an idealization of the irregular cell shape, simpler models are often used. In particular, the circular–cell approximation is very popular due to its low computational complexity (Petrus et al., 1998; Baltzis & Sahalos, 2005, 2009b; Goldsmith, 2005; Pirinen, 2006; Bharucha & Haas, 2008; Xiao et al., 2008; Baltzis, 2010b). Among various performance degradation factors, co-channel interference (CCI) is quite significant since the cells in cellular networks tend to become denser in order to increase system capacity (Stavroulakis, 2003). The development of models that describe CCI generates great interest at the moment. Several reliable models can be found in the