14,118 research outputs found
A unification in the theory of linearization of second order nonlinear ordinary differential equations
In this letter, we introduce a new generalized linearizing transformation
(GLT) for second order nonlinear ordinary differential equations (SNODEs). The
well known invertible point (IPT) and non-point transformations (NPT) can be
derived as sub-cases of the GLT. A wider class of nonlinear ODEs that cannot be
linearized through NPT and IPT can be linearized by this GLT. We also
illustrate how to construct GLTs and to identify the form of the linearizable
equations and propose a procedure to derive the general solution from this GLT
for the SNODEs. We demonstrate the theory with two examples which are of
contemporary interest.Comment: 8 page
A Method to Tackle First Order Differential Equations with Liouvillian Functions in the Solution - II
We present a semi-decision procedure to tackle first order differential
equations, with Liouvillian functions in the solution (LFOODEs). As in the case
of the Prelle-Singer procedure, this method is based on the knowledge of the
integrating factor structure.Comment: 11 pages, late
A generalization of the S-function method applied to a Duffing-Van der Pol forced oscillator
In [1,2] we have developed a method (we call it the S-function method) that
is successful in treating certain classes of rational second order ordinary
differential equations (rational 2ODEs) that are particularly `resistant' to
canonical Lie methods and to Darbouxian approaches. In this present paper, we
generalize the S-function method making it capable of dealing with a class of
elementary 2ODEs presenting elementary functions. Then, we apply this method to
a Duffing-Van der Pol forced oscillator, obtaining an entire class of first
integrals
A solvable model of the evolutionary loop
A model for the evolution of a finite population in a rugged fitness
landscape is introduced and solved. The population is trapped in an
evolutionary loop, alternating periods of stasis to periods in which it
performs adaptive walks. The dependence of the average rarity of the population
(a quantity related to the fitness of the most adapted individual) and of the
duration of stases on population size and mutation rate is calculated.Comment: 6 pages, EuroLaTeX, 1 figur
The hidden prosumer: consumer-citizens participation in the invisible economy of advertising
Este artigo foca a participação do prosumidor - enquanto produtor e consumidor-cidadão – na publicidade e as suas implicações na construção dos conteúdo e dos públicos publicitários, formatando a indústria, produtos e perfis de consumo e a ecologia dos meios de comunicação. Com base na definição de prosumidor de Alvin Toffler, a dupla condição do indivÃduo como produtor e consumidor, e sua designação da chamada economia invisÃvel, analisaremos como a indústria da publicidade enfrenta os desafios colocados por esta participação, incorporando contribuições de prosumidores, como fonte de capital criativo e ferramentas operacionais. Além disso, discutiremos como a interação entre prosumidores e média, especialmente a publicidade, denota um empowerment paradoxal: os prosumidores co-criadores conquistam a sua própria voz na esfera pública, influenciando o conteúdo e ganhando poder de edição sobre a sua substância; mas porque são também são consumidores dos média, isto é, audiência, os prosumidores constroem valor mediático para a publicidade tornando-se parte dos produtos destinados ao consumo. Refletindo além da co-criação sobre a participação below-the-line, menos visÃvel, enuncia-se ainda seu o potencial de cidadania, como meio de construir e influenciar a paisagem quotidiana
What’s in a place? The contribution of strategic communication to placemaking and territorial communication
Set in the field of territorial communication, the aim of this chapter is to
summon the various contributions of strategic communication to placemaking
and promotion, approaching them both through a mind frame path,
as a multi-layered concept, and through an operational approach, as a pragmatic
tool. Going through a number of examples we will reflect on several
experiences to illustrate the potential of strategic communication to add
value to places in different sets and scales, from building a place almost
from scratch to nation branding strategies, from positioning and re-positioning
objectives to building up notoriety or developing communities’
sense of belonging to a territory. We also set an evolutionary frame of the
territorial communication in the light of its strategic dimension, drawing
on key concepts and trends, influences and achievements. The performative
value of strategic communication as a constructive tool of territorial
development is discussed in addition to the communicational added value
of territorial brands, namely by pointing emerging issues such as storytelling
or participatory place communication. Furthermore, we summon ethical
and pragmatic challenges to the debate as inspiration for future research.This work is supported by national funds through FCT – Fundação para a
Ciência e a Tecnologia, I.P., under the project UIDB/00736/2020
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