17 research outputs found

    Interactive Learning in Decision Support

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    De acordo com o dicionário priberam da língua portuguesa, o conceito de Fraude pode ser definido como uma “ação ilícita, punível por lei, que procura enganar alguém ou alguma entidade ou escapar a obrigações legais”. Este tópico tem vindo a ganhar cada vez mais relevância em tempos recentes, com novos casos a se tornarem públicos de uma forma frequente. Desta forma, existe uma procura contínua por soluções que permitam, numa primeira fase, prevenir a ocorrência de fraude, ou, caso a mesma já tenha ocorrido, a detetar o mais rapidamente possível. Isto representa um grande desafio: em primeiro lugar, a evolução tecnológica permite que se elaborem esquemas fraudulentos cada vez mais complexos e eficazes e, portanto, mais difíceis de detetar e parar. Para além disto, os dados e a informação que deles se pode retirar são vistos como algo cada vez mais importante no contexto social. Consequentemente, indivíduos e empresas começaram a recolher e armazenar grandes quantidades de todo o tipo de dados. Isto representa o conceito de Big Data – grandes quantidades de dados de diferentes tipos, com diferentes graus de complexidade, produzidos a ritmos diferentes e provenientes de diferentes fontes. Isto veio, por sua vez, tornar inviável a utilização de tecnologias e algoritmos tradicionais de deteção de fraude, uma vez que estes não possuem capacidade para processar um tão grande conjunto de dados, tão diversos. É neste contexto que a área de Machine Learning tem vindo a ser cada vez mais explorada, na busca por soluções que permitam dar resposta a este problema. Normalmente, os sistemas de Machine Learning são vistos como algo completamente autónomo. Nos últimos anos, no entanto, sistemas interativos nos quais especialistas humanos contribuem ativamente no processo de aprendizagem têm vindo a apresentar um desempenho superior quando comparados com sistemas completamente automatizados. Isto pode verificar-se em cenários em que existe um grande conjunto de dados de diversos tipos e de diferentes origens (Big Data), cenários em que o input é um fluxo de dados ou quando existe uma alteração do contexto no qual os dados estão inseridos, num fenómeno conhecido por concept drift. Tendo isto em conta, neste documento é descrito um projeto cujo tema se insere no contexto da utilização de aprendizagem interativa no suporte à decisão, abordando a temática das auditorias digitais e, mais concretamente, o caso da deteção de fraude fiscal. Desta forma, a solução proposta passa pelo desenvolvimento de um sistema de Machine Learning interativo e dinâmico, na medida em que um dos principais objetivos passa por permitir a um humano especialista no domínio não só contribuir com o seu conhecimento no processo de aprendizagem do sistema, mas também que este possa contribuir com novo conhecimento, através da sugestão de uma nova variável ou um novo valor para uma variável já existente, em qualquer altura. O sistema deve então ser capaz de integrar o novo conhecimento de uma forma autónoma e continuar com o seu normal funcionamento. Esta é, na verdade, a principal característica inovadora da solução proposta, uma vez que em sistemas de Machine Learning tradicionais isto não é possível, visto que estes implicam uma estrutura do dataset rígida, e em que qualquer alteração neste sentido implicaria um reinício de todo o processo de treino de modelos, desta vez com o novo dataset.Machine Learning has been evolving rapidly over the past years, with new algorithms and approaches being devised to solve the challenges that the new properties of data pose. Specifically, algorithms must now learn continuously and in real time, from very large and possibly distributed datasets. Usually, Machine Learning systems are seen as something fully automatic. Recently, however, interactive systems in which the human experts actively contribute towards the learning process have shown improved performance when compared to fully automated ones. This may be so on scenarios of Big Data, scenarios in which the input is a data stream, or when there is concept drift. In this paper, we present a system that learns and adapts in real-time by continuously incorporating user feedback, in a fully autonomous way. Moreover, it allows for users to manage variables (e.g. add, edit, remove), reflecting these changes on-the-fly in the Machine Learning pipeline. This paper describes the main functionalities of the system, which despite being of general-purpose, is being developed in the context of a project in the domain of financial fraud detection

    Long-term thermal sensitivity of Earth’s tropical forests

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    The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate

    Outcomes from elective colorectal cancer surgery during the SARS-CoV-2 pandemic

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    This study aimed to describe the change in surgical practice and the impact of SARS-CoV-2 on mortality after surgical resection of colorectal cancer during the initial phases of the SARS-CoV-2 pandemic

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    Núcleos de Ensino da Unesp: artigos 2009

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    NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

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    Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data

    Characterisation of microbial attack on archaeological bone

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    As part of an EU funded project to investigate the factors influencing bone preservation in the archaeological record, more than 250 bones from 41 archaeological sites in five countries spanning four climatic regions were studied for diagenetic alteration. Sites were selected to cover a range of environmental conditions and archaeological contexts. Microscopic and physical (mercury intrusion porosimetry) analyses of these bones revealed that the majority (68%) had suffered microbial attack. Furthermore, significant differences were found between animal and human bone in both the state of preservation and the type of microbial attack present. These differences in preservation might result from differences in early taphonomy of the bones. © 2003 Elsevier Science Ltd. All rights reserved

    Núcleos de Ensino da Unesp: artigos 2008

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    Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    Long-term thermal sensitivity of Earth’s tropical forests

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    Data from Sullivan et al. (2020) Long-term thermal sensitivity of Earth’s tropical forests. Science. DOI: 10.1126/science.aaw7578.

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    ABSTRACT: The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater rate of decline in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate
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