4,178 research outputs found
When Politicians Talk About Politics: Identifying Political Tweets of Brazilian Congressmen
Since June 2013, when Brazil faced the largest and most significant mass
protests in a generation, a political crisis is in course. In midst of this
crisis, Brazilian politicians use social media to communicate with the
electorate in order to retain or to grow their political capital. The problem
is that many controversial topics are in course and deputies may prefer to
avoid such themes in their messages. To characterize this behavior, we propose
a method to accurately identify political and non-political tweets
independently of the deputy who posted it and of the time it was posted.
Moreover, we collected tweets of all congressmen who were active on Twitter and
worked in the Brazilian parliament from October 2013 to October 2017. To
evaluate our method, we used word clouds and a topic model to identify the main
political and non-political latent topics in parliamentarian tweets. Both
results indicate that our proposal is able to accurately distinguish political
from non-political tweets. Moreover, our analyses revealed a striking fact:
more than half of the messages posted by Brazilian deputies are non-political.Comment: 4 pages, 7 figures, 2 table
Exponentially small quantum correction to conductance
When time-reversal symmetry is broken, the average conductance through a
chaotic cavity, from an entrance lead with open channels to an exit lead
with open channels, is given by , where . We show
that, when tunnel barriers of reflectivity are placed on the leads,
two correction terms appear in the average conductance, and that one of them is
proportional to . Since , this correction is
exponentially small in the semiclassical limit. Surprisingly, we derive this
term from a semiclassical approximation, generally expected to give only
leading orders in powers of . Even though the theory is built
perturbatively both in and in , the final result is exact.Comment: 9 pages, 2 figure
Sintomas do Brasil contemporâneo: tensões discursivas e a educação para a diferença
It is intended to reflect on the moment experienced in Brazil, understanding them as symptoms of Contemporaneity, thinking about social practices and discourses that strain and re-articulate all the time. The deconstruction of historical facts and the refutation of scientific events are some of the examples that we pursue in this reflection, asking us about the educational models and the ways of seeing History, which establish direct relations with the aspects of social exclusion and with subjective formations. In this sense, the truth seems to lose its privileged position and occupy with a certain fragility a place based on the belief in the figure of the modern subject. We propose new perspectives on the fields of knowledge, calling us to think about education for diversity as an indispensable perspective to face the rise of social barbarism.Tiene la intención de reflexionar sobre el momento experimentado en Brasil, entendiéndolos como síntomas de Contemporaneidad, pensando en prácticas sociales y discursos que se tensan y rearticulan en todo momento. La deconstrucción de hechos históricos y la refutación de eventos científicos son algunos de los ejemplos que buscamos en esta reflexión, preguntándonos acerca de los modelos educativos y las formas de ver la Historia, que establecen relaciones directas con los aspectos de exclusión social y con formaciones subjetivas. En este sentido, la verdad parece perder su posición privilegiada y ocupar con cierta fragilidad un lugar basado en la creencia en la figura del sujeto moderno. Depende de nosotros proponer nuevas perspectivas en los campos del conocimiento, llamándonos a pensar en la educación para la diversidad como una perspectiva indispensable para enfrentar el aumento de la barbarie social.Pretende-se refletir acerca do momento vivenciado no Brasil, entendendo-o como sintoma da Contemporaneidade, pensando práticas e discursos sociais que tensionam-se e rearticulam-se a todo instante. A desconstrução de fatos históricos e a refutação de eventos científicos são alguns dos exemplos que perseguimos nesta reflexão, indagando-nos acerca dos modelos educativos e os modos de ver a História, que estabelecem relações diretas com os aspectos de exclusão social e com as formações subjetivas. Nesse sentido, a verdade parece perder sua posição privilegiada e ocupar, com certa fragilidade, um lugar baseado na crença na figura do sujeito moderno. Nos coube propor novos olhares aos campos do saber, convocando-nos a pensar a educação para diversidade como perspectiva indispensável ao enfrentamento da ascensão da barbárie social
Complex Network Tools to Understand the Behavior of Criminality in Urban Areas
Complex networks are nowadays employed in several applications. Modeling
urban street networks is one of them, and in particular to analyze criminal
aspects of a city. Several research groups have focused on such application,
but until now, there is a lack of a well-defined methodology for employing
complex networks in a whole crime analysis process, i.e. from data preparation
to a deep analysis of criminal communities. Furthermore, the "toolset"
available for those works is not complete enough, also lacking techniques to
maintain up-to-date, complete crime datasets and proper assessment measures. In
this sense, we propose a threefold methodology for employing complex networks
in the detection of highly criminal areas within a city. Our methodology
comprises three tasks: (i) Mapping of Urban Crimes; (ii) Criminal Community
Identification; and (iii) Crime Analysis. Moreover, it provides a proper set of
assessment measures for analyzing intrinsic criminality of communities,
especially when considering different crime types. We show our methodology by
applying it to a real crime dataset from the city of San Francisco - CA, USA.
The results confirm its effectiveness to identify and analyze high criminality
areas within a city. Hence, our contributions provide a basis for further
developments on complex networks applied to crime analysis.Comment: 7 pages, 2 figures, 14th International Conference on Information
Technology : New Generation
Bis(tetraphenylphosphonium) bis[N-(2,5-dichlorophenylsulfonyl)dithiocarbimato(2−)-κ2 S,S′]platinate(II)
In the title salt, (C24H20P)2[Pt(C7H3Cl2NO2S3)2], the PtII ion (site symmetry ) is coordinated by two S,S′-bidentate N-(2,5-dichlorophenylsulfonyl)dithiocarbimate ligands, resulting in a slightly distorted PtS4 square-planar geometry. In the crystal, a C—H⋯O interaction is observed, as well as electrostatic attraction between the oppositely charged ions
Increasing the reaction kinetics of alkali-activated fly ash binders for stabilisation of a silty sand pavement sub-base
The paper addresses several options to improve the reaction kinetics of alkali-activated
low-calcium fly ash binders for soil stabilisation in road platforms. For that purpose, an experimental
programme was established to assess the strength evolution, with time, of different
binders, based on ash, lime, sodium chloride and alkali solutions, applied in the stabilisation
of a silty sand. The tests included unconfined compression strength tests, triaxial tests and
seismic wave measurements performed at different curing periods. The results were compared
with a binder made of Portland cement and a commercial additive specifically designed for
soil stabilisation in road applications. The activated ash mixtures with lime were the most
performing producing a significant increase in the reactions development and, consequently,
in the strength gain rate. The sodium chloride significantly improved the lime and lime-ash
mixtures, but provided only a slight improvement in the activated ash mixtures.The authors would like to acknowledge the company CJR Wind – Energy for life, for the funding which enable the presented research; the MCTES/FCT (Portuguese Science and Technology Foundation of Portuguese Ministry of Science and Technology) for their financial support through the SFRH/BPD/85863/2012 scholarship, which is co-funded by the European Social Fund by POCH program; and the Microscopy Unit of the University of Trás- os-Montes e Alto Douro. In addition, a special acknowledgment is also due to PEGOP – Energy Eléctrica, S.A. and LUSICAL – Companhia Lusitana de Cal, S.A. for providing respectively fly ash and lime for this study
Uma análise bibliométrica da literatura internacional sobre colaboração na cadeia de suprimentos
Collaboration has been recognized as an important strategy for supply chain management success. However, previous studies suggest that this issue is little understood and explored, in terms of identifying and organizing the content already developed, as well as in providing reflections and alternatives for its appropriation in the organizational environment. This work sheds light on these issues and aims at systematically mapping the international scientific production on collaboration in supply chain. Bibliometric methods were used by means of structured mapping and systematic analysis of publications found on the Web of Science – Social Sciences Citation Index (WoS-SSCI) database up to 2014. As a result, 173 were retrieved, which were published in 68 journals and written by 380 authors associated with 226 institutions of 32 countries. The bibliometric analysis allowed us to identify the journals that stand out because of the high count of citations and number of articles, which could be used as reference for future studies in this area; among them is the Supply Chain Management an International Journal. From the systematic analysis of highly cited papers and recent papers, we observed a predominance of quantitative studies using surveys and some using structural equation modeling. Based on the paper analysis, we identified some gaps and opportunities for future research. It thus follows that collaboration within the supply chains context is a relevant matter with increasing academic interest, which needs to be further studied for theoretical development and practical implications.Keywords: collaboration, supply chain, bibliometric study.A colaboração tem sido reconhecida como uma importante estratégia para o sucesso da gestão da cadeia de suprimentos. Entretanto, estudos anteriores sugerem que se trata de um tema pouco compreendido e explorado, tanto no sentido de identificar e organizar o conteúdo já desenvolvido quanto no de proporcionar reflexões para a sua apropriação no ambiente organizacional. Este trabalho lança luz sobre essas questões e tem por objetivo mapear sistematicamente a produção científica internacional sobre a colaboração na cadeia de suprimentos. O método utilizado foi o estudo bibliome?trico, por meio do mapeamento estruturado e da análise sistemática das publicações localizadas na base Web of Science – Social Sciences Citation Index (WoS-SSCI) até o ano 2014. Como resultado, foram recuperados 173 artigos, os quais estão publicados em 68 periódicos e escritos por 380 autores vinculados a 226 instituições de 32 países. Entre outros resultados da análise bibliométrica, foram identificados os periódicos que se destacam devido aos altos números de citações e quantidades de artigos, os quais poderão ser tomados como referência para futuras pesquisas nesta área – entre eles está o Supply Chain Management an International Journal. A partir da análise sistemática, verificou-se que a maioria dos artigos selecionados são estudos empíricos com abordagem quantitativa que utilizam survey e alguns que empregam a modelagem de equações estruturais. Nos textos analisados, foi identificado um amplo leque de lacunas e oportunidades para a realização de futuros estudos na área. Conclui-se, portanto, que a colaboração no contexto da cadeia de suprimentos é um assunto relevante e de crescente interesse acadêmico que ainda carece de estudos aprofundados para desenvolvimento teórico e implicações práticas.Palavras-chave: colaboração, cadeia de suprimentos, estudo bibliométrico
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