Engineering Commons^™

Sustainable And Cost-Effective Work Zone Scheduling On Two-Lane Highways With Managed Lanes, Ahmed Z. Edrees

Dissertations

Roadway maintenance projects greatly influence the roadway capacity, resulting in potential traffic disturbances captured by delays. Additionally, costs associated with these projects tend to be exorbitantly extensive. Most agencies and planners try to find a solution that minimizes roadway maintenance costs, traffic delays, crash risks, and environmental impact.

Work zones on two-way two-lane roadway typically avoids high-demand periods. Lane-closure scenario is commonly used and converts the open lane into a phantom intersection, alternating two-direction movements on one lane with the help of a flagger or a temporary signal. Alternatively, using shoulders as temporarily managed lanes allows for simultaneous two-way movements …

Optimizing Speed Profiles For Sustainable Train Operation With Wayside Energy Storage Systems, Leon A. Allen

Dissertations

Large hauling capability and low rolling resistance has put rail transit at the forefront of mass transportation mode sustainability in terms of congestion mitigation and energy conservation. As such, rail vehicles are one of the least energy-intensive modes of transportation and least environmentally polluting. Despite, these positives, improper driving habits and wastage of the braking energy through dissipation in braking resistors result in unnecessary consumption, extra costs to the operator and increased atmospheric greenhouse gas emissions.

This study presents an intelligent method for the optimization of the number and locations of wayside energy storage system (WESS) units that maximize the …

Fast Estimation Model Of Pressure-Temperature Response For Planning Focused Ultrasound Surgery, Tariq Mohammad Arif

Dissertations

High Intensity Focused Ultrasound (HIFU) is becoming a widely accepted modality for extracorporeal non-invasive hyperthermia and surgical procedures. Since ultrasonic transducers need to operate in various challenging body locations, the arrangement of their array elements can be optimized to improve the capability of controlling focus intensity. In the first part of this dissertation, patterns of pressure field variations with several selected design variables (kerf, transducer element’s number and element’s width-height) are studied. These patterns indicate that there is a more suitable shape and arrangement of transducer elements in a specified area to achieve highest possible pressure. In order to obtain …

Optimizing Fare Structure And Service Frequency For An Intercity Transit System, Feng-Ming Tsai

Dissertations

This study presents an approach to jointly optimize service headway and differentiated fare for an intercity transit system with an objective of total profit maximization and with consideration given to the economic and social sustainability of the system. Service capacity and fleet size constraints are considered. The optimization problem is structured into four scenarios which are comprised of the combinations of whether the Ranges of Travel Distance (RTD) is fixed or variable and if the time period is for a single period or for multiple periods. A successive substitution method (specifically, a modified Gauss Southwell method) is applied to solve …

Optimized Scheduling Of Highway Work Zones, Yimin Tang

Dissertations

Highway maintenance activities usually require lane closures and disrupt traffic operations. Because of budget constraints, project deadlines, and the resulting traffic impact, the objective of this dissertation is to improve the efficiencies of traffic operation and maintenance work, and minimize the total project cost (i.e., agency cost and road user cost) by optimizing work zone schedules.

This dissertation focuses on the maintenance projects on multiple-lane highways. The objective total cost function is formulated while considering a discrete maintenance time-cost function and time-dependent traffic diversions. However, the work zone scheduling problem is a combinatorial optimization problem and difficult to solve analytically. …