509,257 research outputs found
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
The Canadian Horror Film: Terror of the Soul edited by Gina Freitag and Andre Loiselle
Review of Gina Freitag\u27s and Andre Loiselle\u27s The Canadian Horror Film: Terror of the Sou
Mechanism Design for Fair Allocation
Mechanism design for a social utility being the sum of agents' utilities
(SoU) is a well-studied problem. There are, however, a number of problems of
theoretical and practical interest where a designer may have a different
objective than maximization of the SoU. One motivation for this is the desire
for more equitable allocation of resources among agents. A second, more subtle,
motivation is the fact that a fairer allocation indirectly implies less
variation in taxes which can be desirable in a situation where (implicit)
individual agent budgetary constraints make payment of large taxes unrealistic.
In this paper we study a family of social utilities that provide fair
allocation (with SoU being subsumed as an extreme case) and derive conditions
under which Bayesian and Dominant strategy implementation is possible.
Furthermore, it is shown how a simple modification of the above mechanism can
guarantee full Bayesian implementation. Through a numerical example it is shown
that the proposed method can result in significant gains both in allocation
fairness and tax reduction
Die bevordering van geesteswetenskaplike studie*)
Hierdie tema sou op ’n verskeidenheid van wyses aangepak kon word: Eerstens is dit moontlik om planne te bedink op grond waarvan die studentegetalle in die geesteswetenskappe verhoog sou kon word. Tweedens is dit moontlik om ’n soort wetenskaplike rasionalisasie te verskaf vir die feit dat die oënskynlik anachronis- tiese geesteswetenskappe nog steeds aangebied word in ’n tyd waarin die hele samelewing in die teken van die wetenskap en die tegniek staan. Dit sou natuurlik ook moontlik wees om die tema aan te pak vanuit ’n statistiese ontleding van die stand van die geesteswetenskappe en daardeur op tendense en ontwikkelingsrig- tinge te dui. Natuurlik sou daar voldoende grond wees om ook die hele kwessie van die gebrekkige finansiering van die geesteswetenskappe aan die orde te stel en ’n pleidooi te lewer vir beter salariëring van geesteswetenskaplik-geskooldes, beter beurse vir studente in die geesteswetenskappe en beslis meer geleenthede vir na- vorsing in die geesteswetenskappe. Voorts sou die uiteindelike werksituasie van die geesteswetenskaplik-geskoolde in oënskou geneem kon word. Indien daar ’n oor- skot van geesteswetenskaplik-geskooldes bestaan, sou dit geremedieer moes word en indien daar ’n tekort aan dergelike geskooldes sou bestaan, sou planne beraam moes word vir die aanmoediging van studie in hierdie rigting
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