In the Dutch railway network, there are a few times per week modifications in the timetable necessary due to unexpected maintenance projects or planned maintenance project that finish later than expected. Moreover, there are about 20 disruptions per day on average. These disruptions can be caused by the infrastructure (e.g. broken switches, no power supply), the weather (e.g. longer braking tim...

In this paper, we address vehicle routing and crew scheduling problems that can be solved by a branch-and-price approach where the column generation subproblem corresponds to a shortest path problem with or without resource constraints. As surveyed in [1] and [2], branch-and-price approaches have been successfully used to solve a wide variety of vehicle routing and crew scheduling applications ...

This paper presents a new multi-depot combined vehicle and crew scheduling algorithm, and uses it, in conjunction with a heuristic vehicle routing algorithm, to solve the intra-city mail distribution problem faced by Australia Post. First we describe the Australia Post mail distribution problem and outline the heuristic vehicle routing algorithm used to find vehicle routes. We present a new mul...

Previous studies on optimization of crew diets have not accounted for choice. A diet selection model with crew choice was developed. Scenario analyses were conducted to assess the feasibility and cost of certain crew preferences, such as preferences for numerous-desserts, high-salt, and high-acceptability foods. For comparison purposes, a no-choice and a random-choice scenario were considered. ...

Rising wildfire suppression expetizditures on public land in the United States have led to increased scrutiny of wildfifne managemefzt practices. One area that has received particular attention is the Forest Service's increasing reliance on contract fire crews. Because a contract crew rate includes several costs that are not included in the wage costs of a Forest Service crew, it is difsicult t...

Nuclear level densities and spin cut-off factors have been deduced for nuclei in the mass region 24‹A‹63,from a microscopic theory, which includes nuclear pairing interaction. Single particle levels for both Seeger and Nilsson potentials were used in the calcdations. Level densities extracted from the theory are compared with their conesponding experimental values, It is found that the overall...

AIMS To describe dental treatment needs and demands of crew on a cruise ship during a world cruise. METHODS The routine dental documentation of a two months period at sea on a cruise ship carrying 999 crew was analysed. Age, gender, diagnosis, treatment performed, percentage of emergency and routine procedures, number of appointments, duration of appointment and time since last visit to the d...