2,609 research outputs found
Spectroscopic Analysis in the Virtual Observatory Environment with SPLAT-VO
SPLAT-VO is a powerful graphical tool for displaying, comparing, modifying
and analyzing astronomical spectra, as well as searching and retrieving spectra
from services around the world using Virtual Observatory (VO) protocols and
services. The development of SPLAT-VO started in 1999, as part of the Starlink
StarJava initiative, sometime before that of the VO, so initial support for the
VO was necessarily added once VO standards and services became available.
Further developments were supported by the Joint Astronomy Centre, Hawaii until
2009. Since end of 2011 development of SPLAT-VO has been continued by the
German Astrophysical Virtual Observatory, and the Astronomical Institute of the
Academy of Sciences of the Czech Republic. From this time several new features
have been added, including support for the latest VO protocols, along with new
visualization and spectra storing capabilities. This paper presents the history
of SPLAT-VO, it's capabilities, recent additions and future plans, as well as a
discussion on the motivations and lessons learned up to now.Comment: 15 pages, 6 figures, accepted for publication in Astronomy &
Computin
Matching Biomedical Knowledge Graphs with Neural Embeddings
Tese de mestrado, Ciência de Dados, Universidade de Lisboa, Faculdade de Ciências, 2020Os grafos de conhecimento são estruturas que se tornaram fundamentais para a organização dos dados biomédicos que têm sido produzidos a um ritmo exponencial nos últimos anos. A abrangente adoção desta forma de estruturar e descrever dados levou ao desenvolvimento de abordagens de prospeção de dados que tirassem partido desta informação com o intuito de auxiliar o progresso do conhecimento científico. Porém, devido à impossibilidade de isolamento de domínios de conhecimento e à idiossincrasia humana, grafos de conhecimento construídos por diferentes indivíduos contêm muitas vezes conceitos equivalentes descritos de forma diferente, dificultando uma análise integrada de dados de diferentes grafos de conhecimento. Vários sistemas de alinhamento de grafos de conhecimento têm focado a resolução deste desafio. Contudo, o desempenho destes sistemas no alinhamento de grafos de conhecimento biomédicos estagnou nos últimos quatro anos com algoritmos e recursos externos bastante trabalhados para aprimorar os resultados. Nesta dissertação, apresentamos duas novas abordagens de alinhamento de grafos de conhecimento empregando Neural Embeddings: uma utilizando semelhança simples entre embeddings à base de palavras e de entidades de grafos; outra treinando um modelo mais complexo que refinasse a informação proveniente de embeddings baseados em palavras. A metodologia proposta visa integrar estas abordagens no processo regular de alinhamento, utilizando como infraestrutura o sistema AgreementMakerLight. Estas novas componentes permitem extender os algoritmos de alinhamento do sistema, descobrindo novos mapeamentos, e criar uma abordagem de alinhamento mais generalizável e menos dependente de ontologias biomédicas externas. Esta nova metodologia foi avaliada em três casos de teste de alinhamento de ontologias biomédicas, provenientes da Ontology Alignment Evaluation Initiative. Os resultados demonstraram que apesar de ambas as abordagens não excederem o estado da arte, estas obtiveram um desempenho benéfico nas tarefas de alinhamento, superando a performance de todos os sistemas que não usam ontologias externas e inclusive alguns que tiram proveito das mesmas, o que demonstra o valor das técnicas de Neural Embeddings na tarefa de alinhamento de grafos do conhecimento biomédicos.Knowledge graphs are data structures which became essential to organize biomedical data produced at an exponential rate in the last few years. The broad adoption of this method of structuring and describing data resulted in the increased interest to develop data mining approaches which took advantage of these information structures in order to improve scientific knowledge. However, due to human idiosyncrasy and also the impossibility to isolate knowledge domains in separate pieces, knowledge graphs constructed by different individuals often contain equivalent concepts described differently. This obstructs the path to an integrated analysis of data described by multiple knowledge graphs. Multiple knowledge graph matching systems have been developed to address this challenge. Nevertheless, the performance of these systems has stagnated in the last four years, despite the fact that they were provided with highly tailored algorithms and external resources to tackle this task. In this dissertation, we present two novel knowledge graph matching approaches employing neural embeddings: one using plain embedding similarity based on word and graph models; the other one using a more complex word-based model which requires training data to refine embeddings. The proposed methodology aims to integrate these approaches in the regular matching process, using the AgreementMakerLight system as a foundation. These new components enable the extension of the system’s current matching algorithms, discovering new mappings, and developing a more generalizable and less dependent on external biomedical ontologies matching procedure. This new methodology was evaluated on three biomedical ontology matching test cases provided by the Ontology Alignment Evaluation Initiative. The results showed that despite both embedding approaches don’t exceed state of the art results, they still produce better results than any other matching systems which do not make use of external ontologies and also surpass some that do benefit from them. This shows that Neural Embeddings are a valuable technique to tackle the challenge of biomedical knowledge graph matching
Money and sociality in South Africa's informal economy
This article examines the interplay of agency, culture and context in order to
consider the social embeddedness of money and trade at the margins of South
Africa’s economy. Focusing on small-scale, survivalist informal enterprise
operators, it draws on socio-cultural analysis to explore the social dynamics
involved in generating and managing wealth. After describing the informal sector
in South Africa, the article elucidates the relationship between money and
economic informality. First, diverse objectives, typically irreducible to the
maximization of profit, animate those in the informal sector and challenge
meta-narratives of a ‘great transformation’ towards socially disembedded and
depersonalized economic relationships. Second, regimes of economic governance,
both state-led and informal, shape the terrain on which informal economic
activity occurs in complex and constitutive ways. Third, local idioms and
practices of trading, managing money and negotiating social claims similarly
configure economic activities. Fourth, and finally, encroaching and often
inexorable processes of formalization differentially influence those in the informal
sector. The analysis draws on these findings to recapitulate both the ubiquity and
centrality of the sociality at the heart of economy, and to examine the particular
forms they take in South Africa’s informal economy.Web of Scienc
Assessment of energy savings related to sustainable solutions improving summer comfort
Estágio realizado na Armines - École des Mines de Paris e orientado pelo Prof. Jérôme AdnotTese de mestrado integrado. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 200
PaaS manager : a platform-as-a-service aggregation framework
The advent of Cloud Computing opened new opportunities in several areas, namely in the application development processes. As consequence, nowadays, PaaS (Platform-as-a-Service) service model allows simpler and flexible deployment strategies of applications, avoiding the need for dedicated networks, servers, stor- age, and other services. Within this context, several PaaS providers exist in the market, but each one having specific characteristics, proprietary technologies and Application Programming Interfaces (APIs). Based on such assumptions, this work addresses the challenge of devising a PaaS aggregation solution with the objective of unifying the information and management processes of applications created in PaaS environments. The proposed solution, denominated as PaaS Manager, take the form of a PaaS API aggregator aiming to struggle the existing lock-in in the PaaS market. In this perspective, this paper describes the specification, development and test of the proposed PaaS Manager solution. As result of this framework, end-users are able to select the most appropriate PaaS platform for an application, interacting with any supported vendor through a unique deployment and management interface.This work has been supported by FCT - Fundação para a Ciência e a Tecnologia within the Project Scope: PEst-OE/EEI/UI0319/2014
Interoperability and portability of cloud service enablers in a PaaS environment
Nowadays, the competition in the telecommunications market is exciting and new entities with value-added services have emerged over the core network of Telecommunications operators (Telcos). These new participants have taken out the operators’ relevance since they are entirely agnostic from infrastructure service connectivity. Therefore Telcos, like Portugal Telecom Inovação (PTIN), need to focus on the provision of services to a user’s point of view to not become just a dumb-pipe between the consumers and Cloud service providers.
This paper proposes a definition of a distributed architecture that allows developers to create and expose services through a Service Delivery Platform (SDP). The benefit of such Cloud-enabled SDP architecture is the portability of service enablers between Platform-as-a-Service (PaaS) providers through a standardized API. Service developers may thus select the more suitable PaaS offering in order to build on-top applications, based on the performance required by a service. An example of applications which can take advantage from more versatile Cloud platforms, is the delivery of mobile context-aware services that react to both environment and user conditions selecting the right type of content (e.g. photos, videos, etc.) to deliver.(undefined
Cloud Platform-as-a-Service
O Cloud Computing tem emergido como sendo um novo paradigma para entrega de serviços através da Internet. Neste mercado em expansão, o serviço de PaaS (Platform-as-a-Service) tem sido objeto de grande interesse por parte das mais variadas organizações permitindo o fácil deployment de aplicações sem necessidade de uma infra-estrutura dedicada, instalação de dependências ou configuração de servidores. No entanto, cada fornecedor de soluções PaaS acaba por gerar um lock-in do utiliza- dor às suas características proprietárias, tecnologias ou APIs (Application Programming Interfaces). Além disso, dando como garantida a conectividade até aos clientes, a rede de operadores como seja o caso da PT (Portugal Telecom) acaba por servir apenas de dumb-pipe entre o fornecedor e os seus clientes
The dynamics of innovation in job search strategies : some empirical findings
We construct a database from the rst 2011 wave of the Portuguese Labor Force Survey and analyze the transitions between labor market states and job search methods during six quarters. In Portugal, the individuals who use more formal job search methods are more likely to get a stable state of employment, while informal contacts, private agencies or newspaper adverts tend to lead to a permanent state of job seeking
ATVs and Agriculture: A Review of the Literature
The purpose of this article was to provide a review of the published literature pertaining to agricultural All-Terrain Vehicle (ATV) use and injury, fatality, exposure assessment, risk estimation and interventions. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) technique was used to identify high quality relevant articles pertaining to ATV-related injury, fatality, exposure assessment, risk estimation, and interventions in an agricultural setting. Inclusion criteria for articles included publications from January 1, 2000 through August 31, 2016, use of injury epidemiology assessment tools, NIOSH hierarchy of controls and the W.K. Kellogg Foundation Logic Model Development Guide. Thirty-four articles met the full inclusion criteria. There have been more than 14,000 ATV-related fatalities since 1982 and a 90% increase in related hospitalizations between the years 2000 to 2005. Occupational ATV-related fatality rates have increased by 300% between 1992 and 2007; with the greatest burden seen in the agricultural sector. Risk factors for ATV-related injury and fatality include riding with passengers, riding on public roadways, riding adult-sized ATVs as a child, lack of formal training, lack of crush protection devices, riding at high speeds, driving up or down hills, traversing hills and modifying ATVs. There are five general types of interventions used to increase ATV safety behaviors and decrease injuries: engineering controls, computer simulations, laws, training and education. The United States lacks consistency in regulations and laws, while Australia is implementing rollover protection for existing ATVs and the Star Rating method, ‘fit for use’ classification system, to help inform consumers about making the best choices for safer and appropriate use
Two scenarios for superconductivity in CeRh2As2
CeRh2As2, a nonsymmorphic heavy fermion material, was recently reported to host a remarkable temperature versus z-axis magnetic-field phase diagram with two superconducting phases. In this material, the two inequivalent Ce sites per unit cell, related by inversion symmetry, introduce a sublattice structure corresponding to an extra internal degree of freedom. Here we propose a classification of the possible superconducting states in CeRh2As2 from the two Ce-sites' perspective. Based on the superconducting fitness analysis and the quasiclassical Eilenberger equations, we discuss two limits: Rashba spin-orbit coupling and interlayer hopping dominated normal state. In both limits, we are able to find two scenarios that generate phase diagrams in qualitative agreement with experiments: (i) intrasublattice pairing with an even-odd transition under z-axis magnetic field and (ii) intersublattice pairing with an odd-odd transition under z-axis magnetic field
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