We develop a model to determine the optimal structure and size of a rail car fleet at a chemical company under uncertainty in demand and travel times as well as substitution between rail car types. First, we formulate an MILP model that accounts for the substitution relations between the types and minimizes the total direct rail car cost under given rail car availability constraints and a prede...

in this paper, a new approach was presented for bus network design which took the effects of three out of four stages of the bus planning process into account. the presented model consisted of three majors steps 1- network design procedure (ndp), 2- frequency determination and assignment procedure (fdap), and 3- network evaluation procedure (nep). genetic algorithm (ga) was utilized to solve th...

Planning for autonomous vehicles remains an important and challenging research topic. This thesis focuses on decentralized planning for autonomous agents performing complex missions. These types of missions often involve a set of tasks, each representing a component of the mission. Task planning algorithms may be used as part of the mission planner to assign agents to tasks; however, the decent...

If your irrigation system is not performing as efficiently as you would like then it may be time to consider updating. This can be done by renewing sprinklers, installing a more advanced control panel, renewing that worn out pump — or a complete redesign of the whole system using modern technology. If you already have Weather-matic equipment installed, Prime offers a full repair and maintenance...

In This Issue In This Issue Ready…set…fuse he fusion of two lipid membranes underlies a huge range of biological phenomena, from infection by enveloped viruses to the secretion of cellular proteins , but a central aspect of membrane fusion has remained mysterious: do the T proteins that mediate fusion act cooperatively or independently? On page 833, Markovic et al. argue that teamwork is the or...

Purpose: The purpose of this paper is to describe the implementation a Fleet Management System (FMS) that plans and controls execution logistics tasks by set mobile robots in real-world hospital environment. FMS developed upon an architecture hosts routing engine, task scheduler, Endorse Broker, controller backend Application Programming Interface (API). engine handles geo-referenced data calcu...

In this paper we model and solve the multi-depot fleet size and mix vehicle routing problem (MDFSMVRP). This problem extends the multi-depot vehicle routing problem and the fleet size and mix vehicle routing problem, two logistics problems that have been extensively studied for many decades. This difficult transportation problem combines complex assignment and routing decisions under the object...

The growth of AVL (Automatic Vehicle Location) systems leads to huge amount of data about different parts of bus fleet (buses, stations, passenger, etc.) which is very useful to improve bus fleet efficiency. In addition, by processing fleet and passengers’ historical data it is possible to detect passenger’s behavioral patterns in different parts of the day and to use it in order to improve fle...

A microscale emission factor model (MicroFacPM) for predicting real-time site-specific motor vehicle particulate matter emissions was presented in the companion paper titled "Development of a Microscale Emission Factor Model for Particulate Matter (MicroFacPM) for Predicting Real-Time Motor Vehicle Emissions". The emission rates discussed are in mass per unit distance with the model providing e...