Much of the existing work on the broadcast channel focuses only on the sending of private messages. In this work we examine the scenario where the sender also wishes to transmit common messages to subsets of receivers. For an L-user broadcast channel there are 2L−1 subsets of receivers and correspondingly 2L−1 independent messages. The set of achievable rates for this channel is a 2 − 1-dimensi...

There is little doubt that electronic commerce has penetrated many people’s—and particularly business’—lives in one way or another, during the past few years. But how many businesses really use the Internet? How do they use it? And how are they planning to use it? When it comes to a precise evaluation of the importance of e-commerce, including its dimensions, growth-rate and role in economic gr...

In a world where different systems have to share the same spectrum, the received (interfering) power may be a more relevant constraint than the maximum transmit power. Motivated by such a spectrum-sharing approach, this paper investigates the behavior of capacity under received-power constraints, modeling for example the maximum interference that one system may inflict on another. The insight o...

As demand for passenger and freight transport on Britain’s railways increases, providing additional capacity and making the best use of the existing infrastructure are priorities for the industry. Since the stations and junctions forming the nodes of the railway network tend to form the constraints on route and network capacity, improved understanding of their operation and capacity characteris...

In this paper, a hub covering location problem is considered. Hubs, which are the most congested part of a network, are modeled as M/M/C queuing system and located in placeswhere the entrance flows are more than a predetermined value.A fuzzy constraint is considered in order to limit the transportation time between all origin-destination pairs in the network.On modeling, a nonlinear mathematica...

An achievable rate region for line networks with edge and node capacity constraints and broadcast channels (BCs) is derived. The region is shown to be the capacity region if the BCs are orthogonal, deterministic, physically degraded, or packet erasure with one-bit feedback. If the BCs are physically degraded with additive Gaussian noise then independent Gaussian inputs achieve capacity.

Due to the variety of products, simultaneous production of different models has an important role in production systems. Moreover, considering the realistic constraints in designing production lines attracted a lot of attentions in recent researches. Since the assembly line balancing problem is NP-hard, efficient methods are needed to solve this kind of problems. In this study, a new hybrid met...

This paper considers the channel capacity of 60GHz wireless communications systems over Rayleigh fading channels and Ricean fading channels. The SNR and therefore capacity varies according to the communication distance. The capacity is presented for line-of-sight (LOS) and non-line-of-sight (NLOS) channels given based on a 60GHz link budget model. Phase shift keying (PSK) modulation is consider...