Electric Aircraft and the Environment: A Literature Review

Historically, the integration of social need, environmental impact, and technological advancement has been a challenging balancing act for growing cities and metropoles. If the balance between social need and environmental sustainability is reached, the increasing advancements and improvements made to electric aircrafts have the potential to steer society towards a new mode of sustainable air. One reason why electric aircraft technology has not grown as fast as other technologies is because there lacked a need for fast advancements. With that said, electric aircraft technologies are improving today due to the demand in heavily populated cities to relieve traffic [5]. Some issues growing cities face are inadequate housing, inefficient infrastructure, and high traffic congestion. According to the Metropolitan Transportation Commission (MTC), traffic congestion within the Bay Area has increased 9% in the past two years [5]. The gridlock in the Bay Area increased as approximately 13,000 cars cross the Bay Bridge daily. A report produced by Arup Corporation reports that the Bay Area is second only to Los Angeles in the intensity of traffic congestion [1]. A study by UCLA determined that the economic boom in the Bay Area in the previous decade had driven the influx of inhabitants to the area [5]. These are two examples of metropolitan cities that are impacted by traffic congestion. To mitigate the negative consequences associated with high traffic congestion, it is beneficial to explore redesigning the infrastructure of metropolitan cities in tandem with residual effects of the economic boom. [5]. This literature review analyzes electric aircraft as a viable solution to high congestion and explores the possible effects of it on the environment

Minimum Equivalent Precedence Relation Systems

In this paper two related simplification problems for systems of linear inequalities describing precedence relation systems are considered. Given a precedence relation system, the first problem seeks a minimum subset of the precedence relations (i.e., inequalities) which has the same solution set as that of the original system. The second problem is the same as the first one except that the ``subset restriction'' in the first problem is removed. This paper establishes that the first problem is NP-hard. However, a sufficient condition is provided under which the first problem is solvable in polynomial-time. In addition, a decomposition of the first problem into independent tractable and intractable subproblems is derived. The second problem is shown to be solvable in polynomial-time, with a full parameterization of all solutions described. The results in this paper generalize those in [Moyles and Thompson 1969, Aho, Garey, and Ullman 1972] for the minimum equivalent graph problem and transitive reduction problem, which are applicable to unweighted directed graphs

On the Exact Solution to a Smart Grid Cyber-Security Analysis Problem

This paper considers a smart grid cyber-security problem analyzing the vulnerabilities of electric power networks to false data attacks. The analysis problem is related to a constrained cardinality minimization problem. The main result shows that an $l_1$ relaxation technique provides an exact optimal solution to this cardinality minimization problem. The proposed result is based on a polyhedral combinatorics argument. It is different from well-known results based on mutual coherence and restricted isometry property. The results are illustrated on benchmarks including the IEEE 118-bus and 300-bus systems