1,142 research outputs found
OCReP: An Optimally Conditioned Regularization for Pseudoinversion Based Neural Training
In this paper we consider the training of single hidden layer neural networks
by pseudoinversion, which, in spite of its popularity, is sometimes affected by
numerical instability issues. Regularization is known to be effective in such
cases, so that we introduce, in the framework of Tikhonov regularization, a
matricial reformulation of the problem which allows us to use the condition
number as a diagnostic tool for identification of instability. By imposing
well-conditioning requirements on the relevant matrices, our theoretical
analysis allows the identification of an optimal value for the regularization
parameter from the standpoint of stability. We compare with the value derived
by cross-validation for overfitting control and optimisation of the
generalization performance. We test our method for both regression and
classification tasks. The proposed method is quite effective in terms of
predictivity, often with some improvement on performance with respect to the
reference cases considered. This approach, due to analytical determination of
the regularization parameter, dramatically reduces the computational load
required by many other techniques.Comment: Published on Neural Network
Pandora: mito e icono para una fiesta real
This work proposes to analyze La estatua de Prometeo by Calderón de la Barca and the allegoric-philosophical purposes of his mythological icon from a tour of the different stages that the repeated reformulation of Pandora's classic myth have determined. This Calderonian iconic metaphor constructs the deep meaning of the text, since his value is multiple and mends to the narrative, educational, aesthetic and symbolic dimensions. Calderón exhume Pandora's myth from his articolación about the duplications that defines the icon and that restore a labyrinthine poetics of the double
Ethical Considerations in Primate Conservation
Due to conflicting human and primate needs in primate-source countries, conservation becomes a hotly debated issue. In an exploration of ethical frameworks and conservation approaches, flaws in current approaches become evident. An alternative, deeper understanding of the role of primates is called for in order to achieve truly sustainable primate conservation
Copy mechanism and tailored training for character-based data-to-text generation
In the last few years, many different methods have been focusing on using
deep recurrent neural networks for natural language generation. The most widely
used sequence-to-sequence neural methods are word-based: as such, they need a
pre-processing step called delexicalization (conversely, relexicalization) to
deal with uncommon or unknown words. These forms of processing, however, give
rise to models that depend on the vocabulary used and are not completely
neural.
In this work, we present an end-to-end sequence-to-sequence model with
attention mechanism which reads and generates at a character level, no longer
requiring delexicalization, tokenization, nor even lowercasing. Moreover, since
characters constitute the common "building blocks" of every text, it also
allows a more general approach to text generation, enabling the possibility to
exploit transfer learning for training. These skills are obtained thanks to two
major features: (i) the possibility to alternate between the standard
generation mechanism and a copy one, which allows to directly copy input facts
to produce outputs, and (ii) the use of an original training pipeline that
further improves the quality of the generated texts.
We also introduce a new dataset called E2E+, designed to highlight the
copying capabilities of character-based models, that is a modified version of
the well-known E2E dataset used in the E2E Challenge. We tested our model
according to five broadly accepted metrics (including the widely used BLEU),
showing that it yields competitive performance with respect to both
character-based and word-based approaches.Comment: ECML-PKDD 2019 (Camera ready version
Behavioural Changes in Parenting Female Mantled Howler Monkeys (Alouatta palliata)
Parenting in mantled howler monkeys (Alouatta palliata) requires a new set of energetic and behavioural demands. Because of constraints presented by the infant, as well as the increased energy requirements associated with mothering, parenting females need to change their activity patterns to ensure the successful upbringing of their offspring. This study of wild mantled howler monkeys was conducted to examine differences in activity between parenting and non-parenting adult females. Twenty two hours of continuous sampling on focal individuals was collected over the course of ten days in August at a study site in Nicaragua. It was found that the two groups do differ in their activity patterns: parenting females spent a larger percent of their time resting, feeding and interacting, but a lower percent of their time travelling when compared to non-parenting females. Further, it was found that parenting females engaged in scanning behaviours more frequently, and engaged in bridging (a locomotor behaviour) less frequently. These results suggest that parenting female mantled howler monkeys adopt an energy-minimizing activity pattern wherein the mothers compensate for their increased energetic requirements by only slightly increasing their food intake and instead drastically increasing the amount of time spent resting
Effects of minimum winter temperatures on southern pine beetle (\u3ci\u3eDendroctonus frontalis\u3c/i\u3e) mortality on Long Island, N.Y.
Dendroctonus frontalis (the southern pine beetle) was discovered on Long Island, New York in 2014. Additional infestations have since been located in upstate New York, Rhode Island, Connecticut and Massachusetts. Previously found as far north as New Jersey and Pennsylvania, this range expansion now represents the current northern distribution limits of D. frontalis. Minimum winter temperatures are a meaningful driver of population dynamics and mortality in D. frontalis, and understanding this relationship at the northern range limits can help forest managers better predict and prepare for outbreaks. Studies addressing the relationship between temperature and beetle mortality, and the thermal buffering that host trees provide, have occurred only as far north as New Jersey, and in tree species other than pitch pine (Pinus rigida), the primary host of D. frontalis in the north. I propose a study that will replicate the work completed in New Jersey and the south. I will examine the relationship between minimum winter temperatures and D. frontalis mortality, the thermal buffering potential of pitch pine, and the presence of prepupae (the most cold-tolerant life stage) during the overwintering period. Research will be performed on Long Island, from November 2015 – March 2015, at three mixed species stands of pitch pine infested by D. frontalis. Data loggers attached to paired thermocouples will monitor differences between air and phloem temperatures. Bark samples will be extracted monthly from four trees at each site; percent larval mortality will be correlated with the air temperatures, and the presence of different life stages and their position within the tree will be determined. Data will be used to feed models aimed at predicting annual outbreak potential
Unfit bodies: HIV, care and politics of survival among young people in Maputo
With my research project, I aim to investigate the politics of care and adherence in the biomedical
setting related to antiretroviral therapy and how they have affected young people living with HIV.
My goal during fieldwork, and the purpose of this work, is to adopt a political dimension in the
study of AIDS (Fassin et al. 2007). In other words, to try to maintain two attentive gazes – one on
history at work on the global level and another on history as lived in the local space; to observe
and analyse the state policies and the politics of subjects (Fassin et al. 2007). I sought to explore
the everyday lives of young people between eleven and twenty years old who contracted the virus
through mother-to-child transmission (vertical transmission) and who manifest difficulties in
complying with treatment.
My understanding of patients’ life histories, their interactions with the policies of care and theirs
experiences with regards to illness episodes allow me to generate associations between the
clinical and the social course of the disease, including such themes as health-seeking behaviour,
adherence to therapy and agency.
My aim is to explore how care is provided in Mozambique and specifically how adherence to
antiretroviral treatment is affected by the social context in which young people live. I address, in
particular, the ways in which families understand and negotiate medical services and adherence
politics and how emotions come into play during the care process.Com o meu projeto de tese, procuro investigar as políticas de cuidados e aderência a terapia
antirretroviral no contexto biomédico e como estas afetam os jovens que vivem com o vírus do
HIV na cidade de Maputo, em Moçambique. O meu objetivo durante o trabalho de campo, e o
objetivo deste trabalho, é adotar uma dimensão política no estudo da SIDA (Fassin et al. 2007).
Por outras palavras, tentar manter dois olhares distintos - um sobre a história a nível global e
outro sobre a história vivida no espaço local, observando e analisando as políticas de estado e as
políticas dos sujeitos (Fassin et al. 2007).
Procuro explorar a forma como os cuidados são prestados e especificamente como a adesão
ao tratamento antirretroviral é influenciada pelo contexto social em que os jovens vivem. Abordo,
em particular, as formas das famílias compreender e negociar os serviços médicos e as políticas
de aderência e como as emoções entram em jogo durante o processo de prestação de cuidados. A
tese visa contribuir para o conhecimento antropológico sobre questões relacionadas com cura,
seropositividade e políticas publicas em contextos sócio económicos desfavorecidos centrando-se
nos casos etnográficos para uma visão que destaca a necessidade de uma atenção maior aos
cuidados multidimensional para as pessoas seropositivas.
Através do trabalho de campo - que ocorreu em Maputo, capital de Moçambique, entre
outubro de 2016 e fevereiro de 2018 - procuro explorar a vida quotidiana dos jovens entre os
onze e os vinte anos de idade que contactaram o vírus através da transmissão de mãe para filho
(transmissão vertical) e que manifestam dificuldades em cumprir o tratamento.
Durante o campo, participei em atividades de um centro de dia para pessoas em situação
socioeconómica desfavorecida, tendo a oportunidade de acompanhar as atividades de apoio
psicossocial e conhecer os jovens participantes na investigação. Lentamente, o campo tornou-se
itinerante incluindo outros lugares de investigação como centros de saúde e hospitais.
Paralelamente, mantive um olhar nas políticas publicas e realizei uma parte da pesquisa em
instituições e ONG que trabalham com questões relacionadas com o HIV/SIDA.
Esta tese encontra-se estruturada em uma introdução, seis capítulos e uma conclusão. No
primeiro capítulo vou explorar os desafios enfrentados nos aspetos metodológicos durante o
trabalho de campo. A chegada ao campo, os seu tempos dilatados e os primeiros encontros,
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levaram-me a uma lenta mas constante reformulação e reflexão de possíveis métodos e
ferramentas a implementar.
No segundo capítulo, o meu objetivo é mostrar como a narrativa global em torno da SIDA, e
as principais campanhas propostas pelos atores globais, apresentam tensões com as respostas à
pandemia em contextos locais. Além disso, ao mostrar alguns cenários que tive a oportunidade de
observar na Conferência Internacional da SIDA (IAC) em 2018 em Amesterdão, este capítulo
serve de enquadramento para os capítulos seguintes, que ilustrarão mais especificamente os
desafios no terreno na implementação dos objetivos propostos pela saúde global.
No terceiro capítulo, irei traçar a história do sector da saúde em Moçambique para melhor
compreender as «intervenções para o combate a HIV/SIDA». O principal objetivo deste capítulo
é fornecer o contexto histórico para melhor localizar as práticas de saúde e da cura, tendo em
consideração que os legados coloniais e pós-coloniais aparecem no quotidiano dos centros de
saúde na perspetiva dos profissionais de saúde e dos pacientes.
O quarto capítulo introduz a multiplicidade de cuidados e políticas da saúde no contexto
moçambicano atual. Vou explorar de que forma os cuidados de saúde são prestados nos centros
públicos e destacarei algumas das dificuldades estruturais que os profissionais de saúde e os
jovens pacientes enfrentam diariamente.
O quinto capítulo analisa a ligação entre cuidados de saúde e emoções. Após uma breve
descrição de uma clínica coordenada por uma ONG internacional especializada em doentes
infetados pelo vírus do HIV com complicações, refletirei sobre a forma como as questões
humanitárias lidam com a sobrevivência e a morte na «emergência crónica da HIV/SIDA».
O último capítulo mostra mais uma história em que são delineadas zonas de abandono social
e em que as pessoas vulneráveis permanecem presas, deixando pouca esperança de adesão e
estratégias de sobrevivência. Através da história de Joana mostrarei como diferentes modelos de
cuidados e tratamentos se sobrepõem, criando uma perigosa articulação entre a violência
experimentada na esfera familiar (e espiritual) e a praticada pelos cuidados médicos
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