5,590 research outputs found
Characterizing Attention Cascades in WhatsApp Groups
An important political and social phenomena discussed in several countries,
like India and Brazil, is the use of WhatsApp to spread false or misleading
content. However, little is known about the information dissemination process
in WhatsApp groups. Attention affects the dissemination of information in
WhatsApp groups, determining what topics or subjects are more attractive to
participants of a group. In this paper, we characterize and analyze how
attention propagates among the participants of a WhatsApp group. An attention
cascade begins when a user asserts a topic in a message to the group, which
could include written text, photos, or links to articles online. Others then
propagate the information by responding to it. We analyzed attention cascades
in more than 1.7 million messages posted in 120 groups over one year. Our
analysis focused on the structural and temporal evolution of attention cascades
as well as on the behavior of users that participate in them. We found specific
characteristics in cascades associated with groups that discuss political
subjects and false information. For instance, we observe that cascades with
false information tend to be deeper, reach more users, and last longer in
political groups than in non-political groups.Comment: Accepted as a full paper at the 11th International ACM Web Science
Conference (WebSci 2019). Please cite the WebSci versio
The maximum number of cliques in graphs without large matchings
Given two graphs and , the maximum number of copies of in an
-free graph on vertices is denoted by and is called the
Generalized Tur\'{a}n number. When , it reduces to the classical
Tur\'{a}n number . In 1961, Erd\H{o}s and Gallai proved that where
is a matching of size . In this note, we prove that for any
, Comment: Zoltan Furedi, Alexandr Kostochka and Ruth Luo's paper "A variation
of a theorem by Posa" indicates an even shorter proo
Classical Amplitudes in Gravitational-Wave Physics
In this thesis, we study emission amplitudes for the class of nonlinear
processes of tails, which are processes of order , and represent the
effect of scattering gravitational radiation off the static background
curvature, including not only mass tails but also the "failed" tails due to the
angular momentum of the source. As originally shown in our work, some of these
amplitudes present anomalies, which are then properly understood and corrected
with field theory tools which have straightforward counterpart in traditional
methods. We also investigate the relation between emission and self-energy
diagrams and, in particular, show that a correction to the anomalous
self-energy diagrams is necessary to correctly account for conservative terms
that arise from radiative processes. From this, we obtain the correct
contribution to the conservative 5PN stemming from the electric quadrupole
angular momentum failed tail, correcting previous results in the literature.
Besides this, we also compute for the first time the conservative contributions
from the angular momentum failed tail, for arbitrary multipole moments.
Subsequently, we explore the natural higher-order extension (of order
) of the mass tails, called tails of tails, for generic electric and
magnetic multipoles. As we will see, both long- and short-distance divergences
are encountered, which are then properly understood and dealt with in terms of
standard renormalization techniques. In this case, we are able to resum the
logarithmic contributions through the integration of the renormalization group
equation.
Thus, in this thesis, we have extended the post-Newtonian perturbative
expansion in the particularly thorny region of processes involving the mixture
of radiative and potential modes.Comment: PhD thesis, 137 page
The Use of Digital Media for the Employer Brand Management in Hotels
Os colaboradores exercem um papel fulcral no sucesso da marca dos hotéis. Existe
um número incontável de marcas de hotéis, cada uma com as suas características únicas,
o que requer diferentes colaboradores para darem vida às suas promessas. Estes devem
estar em sintonia com os valores e requisitos da marca do hotel de modo a poderem
representá-la adequadamente durante a interação com os hóspedes. Os gestores devem
comunicar corretamente as suas employer brands de modo a atrair os colaboradores
desejados.
As empresas enviam sinais sobre o seu posicionamento enquanto empregadoras
sempre que utilizam um meio de comunicação online. Estas devem apresentar aos
potencias candidatos informações claras e precisas de modo a permitir-lhes avaliar a sua
afinidade com a empresa mesmo antes de se candidatarem. Assim, a hipótese de ocorrer
um emparelhamento entre os colaboradores e os seus empregadores aumenta. Os gestores
devem tomar especial atenção à forma como comunicam o seu posicionamento enquanto
empregadores de modo a potencializar ativamente este emparelhamento.
Neste estudo, explorou-se como dez das maiores redes hoteleiras do mundo utilizam
os seus websites de recrutamento para apresentar o seu posicionamento enquanto
empregadoras. Paralelamente, analisou-se como estas redes comunicam aos seus
potenciais colaboradores, através de anúncios de trabalho, os valores da empresa e os
benefícios que estas oferecem. Para tal, seguiu-se um design qualitativo e adotou-se uma
abordagem abdutiva.
O presente estudo demonstrou, por meio de uma template analysis, que as redes
hoteleiras avaliadas gerem explicitamente as suas estratégias de employer branding com
o intuito de atraírem apenas colaboradores que partilham os seus valores e objetivos.
Também revelou que os hotéis que promovem um ambiente de trabalho socialmente
diverso são potencialmente mais atrativos enquanto empregadores. Finalmente,
apresentam-se recomendações sobre como os gestores de hotéis podem melhorar a
comunicação das suas employer brands através dos meios digitais.A significant part of a hotel's brand success relies on its employees. There are many
hotel brands, each with their unique characteristics, demanding employees who give life
to their brand promises. To assure employees know how to represent it while interacting
with guests, they must aline with company values and requirements. Managers must know
how to communicate their employer brands to attract the right employees.
Companies send signals about their employer positioning whenever they use online
communication. Employers must offer potential candidates clear and precise information,
allowing them to judge their fit within the company, even before applying for the job. By
doing so, employers and employees increase their chance for a match. To actively
enhance this match, managers should pay attention to how they communicate their
employer positioning.
This study explored how ten of the world’s largest hotel chains use their recruiting
websites to present their employer positioning and communicate their values and
employee value proposition on their job advertisements. A qualitative design, adopting
an abductive approach, was used.
Through a template analysis, this study found that these companies, while intending
to attract employees who share similar values and objectives, are explicitly managing
their employer branding strategies. Further, this study revealed that promoting a socially
diverse work environment is a relevant aspect that helps a company attract employees.
Managerial recommendations associated with how managers might improve their
employer branding online communications are discussed in this paper
Hardship in international commercial contracts. A comparative analysis of the rules in transnational Commercial Law
Os contratos desempenham função imprescindível na economia moderna, estabelecendo expectativas de partes que desejam negociar. Estas partes devem ter autonomia para contratar, desde que respeitado o princípio da pacta sunt servanda. Por outro lado, pela racionalidade econômica dos agentes, eles buscarão a resolução do contrato (ou, pelo menos, sua renegociação) a partir do momento em que este deixar de se tornar vantajoso, o que pode ocorrer devido a acontecimentos supervenientes que frustrem a função econômica idealizada. Caso as partes não contratem essa alocação de riscos, é necessário buscar mecanismos que solucionem o problema. Várias normas internacionais buscaram tratar dessa questão, como a Convenção de Viena sobre Compra e Venda Internacional de Mercadorias (CISG), os Princípios UNIDROIT e os Princípios de Direito Contratual Europeu. Se, por um lado, os dois últimos tratam expressamente de casos de hardship, por outro lado a CISG possui somente uma cláusula genérica de exoneração que cria dúvidas quanto ao seu escopo de aplicação. Diante deste cenário plural, este artigo discute como interpretar situações de hardship em contratos comerciais internacionais sob este conjunto de normas, quais soluções são mais apropriadas para as necessidades do comércio e como estas normas internacionais interagem entre si para harmonizar o direito comercial internacional.Contracts have a vital role in modern economy, establishing parties’ expectations when contracting. Parties must have autonomy to enter into contracts, providing they respect the principle of pacta sunt servanda (sanctity of the contracts). On the other hand, due to their economic rationality, parties will often seek contract termination (or, at least, its renegotiation) once it is not profitable anymore, which can happen due to supervening events that frustrate the economic function of the contract. When these risks are not allocated in the contract, it is necessary to find mechanisms to solve the problem. Many international rules deal with the issue, such as the United Nations Convention on Contracts for the International Sale of Goods (CISG), the UNIDROIT Principles and the Principles of European Contract Law. If, on the one hand, the two latter expressly deal with hardship cases, on the other hand the CISG has only a generic clause of exoneration that creates doubts about its scope of application. Under this variegated framework, this paper discusses how to interpret hardship problems in international commercial contracts under this set of rules, which remedies are best suited for the needs of trade and how the international rules should interact to harmonize international commercial law
Quantum revival patterns from classical phase-space trajectories
A general semiclassical method in phase space based on the final value
representation of the Wigner function is considered that bypasses caustics and
the need to root-search for classical trajectories. We demonstrate its
potential by applying the method to the Kerr Hamiltonian, for which the exact
quantum evolution is punctuated by a sequence of intricate revival patterns.
The structure of such revival patterns, lying far beyond the Ehrenfest time, is
semiclassically reproduced and revealed as a consequence of constructive and
destructive interferences of classical trajectories.Comment: 7 pages, 6 figure
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