$($a$)(30$ pts$)$ Usually a disaster causes disruptions in many

critical infrastructures, such as electric power, natural gas,

telecommunication and transportation systems. It is important

to quickly recover infrastructure from a disruption caused by

a disaster. Propose a deterministic optimization model $($such

as an LP model, ILP model or Network model$)$ to determine a

recovery plan that can minimize the time to restore a

disrupted transportation network in order to deliver enough

disaster relief to affected communities.

$($In your response, please include a brief description of the

optimization problem, and any assumptions you made.$)$