Consider a network facility location problem where congestion arises at facilities, and is represented by delay functions that approximate the queueing process. We strive to minimize the sum of customers' transportation and waiting times, and facilities' xed and variable costs. The problem is solved using a column generation technique within a Branch-and-Bound scheme. Numerical results are repo...

This paper presents a new car-following model which aims to capture some of the key motorway flow characteristics, namely traffic breakdown, hysteresis, shockwave propagation as well as close-following behaviour. The model proposes three different driving states: non-alert, alert and close-following. Under the different driving states, drivers apply different reaction time and acceleration. Thi...

When packet loss rate exceeds a given threshold, received audio and video become unintelligible. A congested router transmitting multimedia packets, while inflicting a packet loss rate beyond a given threshold, effectively transmits useless packets. Useless packet transmission wastes router bandwidth when it is needed most. We propose an algorithm to avoid transmission of useless multimedia pac...

Web caches are installed to reduce the receivers’ latency and save network bandwidth. These caches need to cooperate in order to improve their performance. A popular technique to make caches cooperate is by setting up a caching hierarchy. However, there are several problems associated with a caching hierarchy: i) every hierarchy level introduces additional delay, ii) redundant document copies a...