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Date of Award


Access Type

Campus Access

Document type


Degree Name

Doctor of Philosophy (PhD)

Degree Program

Isenberg School of Management

First Advisor

Agha Iqbal Ali

Second Advisor

Ahmed Ghoniem

Third Advisor

Traci J. Hess

Subject Categories

Business Administration, Management, and Operations | Operational Research


The spatial dispersion of the population of a country is a function of its geography, history, and economic development. Enabling access to services and products for spatially dispersed populations is evermore pertinent in today's fiscally constrained socio-political landscape and relevant to both the public and private sectors. Consumer access is improved when larger segments of the population have access within shorter threshold distances, hence consuming less energy. A higher quality of access to centers that provide a service can be brought about by improving the infrastructure in a manner that facilitates access for larger segments of the population of a country or a region.

This dissertation develops models for locating centers that address the enabling of access to centers for distance differentiated segments of the population of a region, whether a continent, country, state, or a city. A network of centers provides better access if the centers are located so as to serve maximal populations within each of multiple threshold distances. The models incorporate the consumer's higher utility for shorter distances by employing concentric discs or concentric rings of multiple distance thresholds to account the percentages of the population that are afforded a specific quality of access.

The model, referred to as the Multiple-Concentric-Disc Location Model , uses multiple distance thresholds modeled using concentric discs, to differentiate access that is afforded to segments of the population. The model is applied to examining access to locations of branches of the Registry of Motor Vehicles and access to locations of Walmart stores in the Commonwealth of Massachusetts. Further, the use of the model to reveal the relationship between the geographic dispersion of a population and its access to centers-and thereby allow an examination of the challenges of locating centers in different regions of the world-is demonstrated via an extended application of the model to India, Africa, Europe, and USA. Another model, which is referred to as the Multiple-Concentric-Ring Location Model with Utility Decay , brings visibility to the differences in distance to centers for populations within each of a set of concentric rings by aggregating all populated places that are within each concentric ring. Model incorporates the consumer's utility for distance and frequency of usage and assumes that a distance decay function captures the consumer's utility by ascribing probabilities that a consumer will access a center that is within a specified distance. The use of these models to inform location decisions in a variety of infrastructure and economic development scenarios is also demonstrated.

The computational studies in this dissertation require generating instances of the location models for multiple regions of the world. To facilitate these studies, a major component of the research is the ability to generate the data required for instances of each of the models, for any region, whether a continent, a country, a state, or a city. To facilitate solution of thousands of model instances, special purpose software employing efficient computational algorithms and complex data structures has been developed to generate the data files-in metric or imperial systems of measurement-for model instances. Visualization procedures for generating layered maps have been developed to facilitate discussion. Computational studies involving thousands of model instances, each with up to 598,488 variables and 448,526 constraints, reveal insights about possible access to services and products for a country.