3,089 research outputs found
Classifying heart sounds using multiresolution time series motifs : an exploratory study
The aim of this work is to describe an exploratory study on the use of a SAX-based Multiresolution Motif Discovery method for Heart Sound Classification. The idea of our work is to discover relevant frequent motifs in the audio signals and use the discovered motifs and their frequency as characterizing attributes. We also describe different configurations of motif discovery for defining attributes and compare the use of a decision tree based algorithm with random forests on this kind of data. Experiments were performed with a dataset obtained from a clinic trial in hospitals using the digital stethoscope DigiScope. This exploratory study suggests that motifs contain valuable information that can be further exploited for Heart Sound Classification
Classifying heart sounds using SAX motifs, random forests and text mining techniques
In this paper we describe an approach to classifying heart sounds (classes Normal, Murmur and Extra-systole) that is based on the discretization of sound signals using the SAX (Symbolic Aggregate Approximation) representation. The ability of automatically classifying heart sounds or at least support human decision in this task is socially relevant to spread the reach of medical care using simple mobile devices or digital stethoscopes. In our approach, sounds are firrst pre-processed using signal processing techniques (decimate, low-pass filter, normalize, Shannon envelope). Then the pre-processed symbols are transformed into sequences of discrete SAX symbols. These sequences are subject to a process of motif discovery. Frequent sequences of symbols (motifs) are adopted as features. Each sound is then characterized by the frequent motifs that occur in it and their respective frequency. This is similar to the term frequency (TF) model used in text mining. In this paper we compare the TF model with the application of the TFIDF (Term frequency - Inverse Document Frequency) and the use of bi-grams (frequent size two sequences of motifs). Results show the ability of the motifs based TF approach to separate classes and the relative value of the TFIDF and the bi-grams variants. The separation of the Extra-systole class is overly dificult and much better results are obtained for separating the Murmur class. Empirical validation is conducted using
real data collected in noisy environments. We have also assessed the cost-reduction potential of the proposed methods by considering a fixed cost model and using a cost sensitive
meta algorithm.Portuguese Funds through the FCT - Fundacao para a Ciencia e a Tecnologia (proj. FCOMP-01-0124-FEDER-037281 and FCOMP-01-0124-FEDER-PEst-OE/EEI/UI0760/2014)
Impactes percebidos da Capital Europeia da Juventude 2012
This paper examines the economic and sociocultural impacts perceived by participants and residents of the hosting of the European Youth Capital 2012 (EYC 2012) by Braga, Portugal. During the EYC 2012, a survey was applied to 512 individuals, complemented by the implementation of a focus group. Several statistical procedures, including principal components analysis, were carried out in order to identify the impacts of the event. From the results obtained, we could conclude that the hosting of the EYC did not attract a large amount of visitors to the city. The younger respondents, predominant in the sample, tended to keep a more positive assessment of the impacts of the EYC 2012, as well as women when compared to men.O presente artigo analisa os impactes econĂłmicos
e socioculturais percebidos pelos participantes
e residentes em Braga da realização
da Braga Capital Europeia da Juventude 2012
(EYC 2012). Durante a EYC 2012, um inquérito
foi aplicado a 512 indivĂduos, complementado
pela realização de um grupo focal. Vários
procedimentos estatĂsticos, incluindo a análise
de componentes principais, foram realizados
com o objetivo de identificar os impactes percebidos
do evento. A partir dos resultados obtidos,
podemos concluir que a realização da EYC
2012 nĂŁo atraiu uma significativa quantidade de
visitantes Ă cidade de Braga. Os inquiridos mais
jovens, predominantes na amostra, revelaram
uma avaliação mais positiva dos impactes da
EYC 2012, bem como as mulheres, quando
comparadas com os homens.Project Lab2PT - Landscapes, Heritage and Territory Laboratory - AUR/04509 and from FCTMEC through national funds and when applicable the FERDER co-financing, under the new partnership agreementCompete 2020; Portugal 2020, Feder; FC
EzrA Contributes to the Regulation of Cell Size in Staphylococcus aureus
EzrA is a negative regulator of FtsZ in Bacillus subtilis, involved in the coordination between cell growth and cell division and in the control of the cell elongation–division cycle. We have now studied the role of the Staphylococcus aureus homologue of the B. subtilis EzrA protein and shown that it is not essential for cell viability. EzrA conditional and null mutants have an overall increase of the average cell size, compared to wild type strains. In the larger ezrA mutant S. aureus cells, cell division protein FtsZ and the cell wall synthesizing Penicillin Binding Proteins (PBPs) are not properly localized. This suggests that there may be a maximum cell diameter that allows formation of a Z-ring capable of recruiting the other components of the divisome and of driving cytokinesis. We propose that the major role of EzrA in S. aureus is in cell size homeostasis
A Paraneoplastic Syndrome to Remember: A Case of Disseminated Intravascular Coagulation in Lung Cancer
Disseminated intravascular coagulation (DIC) is an acquired syndrome characterized by the widespread activation of coagulation. It can
present as an acute life-threatening emergency or as a chronic process. Mortality is highly dependent on the reversibility of the aetiology
and degree of coagulation impairment, so treatment of the underlying cause is vital. The authors present the case of a 57-year-old man
whose inaugural presentation of lung cancer was chronic DIC, characterized by three thrombotic events, followed by acute DIC, culminating
in death. Metastatic lung cancer was diagnosed only after death
An intelligent home automation control system based on A novel heat pump and wireless sensor networks
One of technology's main goals is to providing comfort to humans. However, in order to be an aid, it has to be easy to install, use and maintain. The ever growing complexity of technological systems can only be achieved by converging different technologies. This is usually expressed as Cyber-Physical Systems (CPS), previews the symbiosis of several technologies in order to make them more accessible. This paper attempts to demonstrate the integration between two technologies such as: Heat-pump System and Wireless Sensor Network (WSN) to provide a new control mechanism for new building generations so-called smart houses. The proposed control architecture benefits from our developed WSN hardware platform. It enables the user to control and monitor the ventilation system using our developed mobile application and/or a personal computer. Also, the performance of the proposed hardware platform is measured in three different environments in order to observer the coverage area of the WSN.Tiago Gomes is supported by FCT, the Portuguese Foundation for Science and Technology (grant SFRH/BD/90162/2012). This work is supported by FEDER through COMPETE and national funds through FCT - Foundation for Science and Technology in the framework of the project FCOMP-OI-0124-FEDER-022674
Estrutura pré- e pós-corte de capim Marandu em função da face de exposição ao sol e distância do renque em sistema silvipastoril
A avaliação estrutural do dossel Ă© uma maneira de garantir o entendimento dos mecanismos que governam o acĂşmulo de forragem em sistemas de produção. O sombreamento total ou parcial de forrageiras produzidas em sistemas Silvipastoril está atrelado a uma discussĂŁo fun damental para o entendimento das respostas estruturais de gramĂneas tropicais. O objetivo foi avaliar o comportamento e as caracterĂsticas morfolĂłgicas e estruturais do capim Marandu (Brachiaria brizantha cv. Marandu), em função da face de exposição (norte e sul) e distância (3, 6, 10 e 15 metros) das arvores no sistema Silvipastoril. O delineamento foi inteiramente casualizado, em parcela subdividida (64 m²), com quatro repetições. DossĂ©is manejados no sistema Silvipastoril, tanto na linha quanto na face, possuem valores mĂ©dios de Ăndice de interceptação luminosa (IL), Ăndice de área foliar (IAF) e alturas semelhantes, no prĂ©- e no pĂłs-corte. A altura em pĂłs-corte foi de 12,75 cm, muito prĂłxima da meta de resĂduo (15 cm), e correspondeu a um IAF mĂ©dio de 2,75 e ângulo da folhagem (ANG) de 49,5Âş e interceptação luminosa (IL) de 75,94%. No prĂ©-corte os ângulos foliares corresponderam a um valor mĂ©dio de 40,2Âş. A altura foi em mĂ©dia, 28 cm com IL de 95,4%. As caracterĂsticas estruturais do pasto de Brachiaria brizantha cv. Marandu em sistema silvipastoril nĂŁo foi influenciado pela face de exposição e distância do renque, enquanto as árvores tĂŞm atĂ© 9 metros de altura
MIGRATE: mobile device virtualisation through state transfer
Delegation of processing tasks to the network has moved from cloud-based schemes to edge computing solutions where nearby servers process requests in a timely manner. Virtualisation technologies have recently given data cloud and network providers the required flexibility to offer such on-demand resources. However, the maintenance of close computing resources presents a challenge when the served devices are on the move. In this case, if processing continuity is desired, a transference of processing resources and task state should be committed to maintain the service to end devices. The solution here presented, MIGRATE, proposes the concept of virtual mobile devices (vMDs) implemented as Virtual Functions (VxF) and acting as virtual representatives of physical processing devices. vMDs are instantiated at the edge of the access network, following a Multi-Access Edge Computing (MEC) approach, and move across different virtualisation domains. MIGRATE provides seamless and efficient transference of these software entities to follow the real location of mobile devices and continue supporting their physical counterparts. Software Defined Networks and Management and Operation functions are exploited to “migrate” vMDs to new virtualisation domains by forwarding data flows to the former domain until the new one is prepared, while a distributed data base avoids the transference of data. The solution has been deployed in a reference vehicular scenario at the Institute of Telecommunications Aveiro premises within the 5GINFIRE European project. In particular, the system has been evaluated under different virtualisation domains to study the operation of the migration approach in a vehicular monitoring scenario. The results validate the system from the application viewpoint with a Web monitoring tool, and the migration of the digital twin provided as VxF is analysed attending to the modification of data flows, indicating a seamless transition between virtualisation domains in a timely manner.publishe
Predicting hydration Gibbs energies of alkyl-aromatics using molecular simulation : a comparison of current force fields and the development of a new parameter set for accurate solvation data
The Gibbs energy of hydration is an important quantity to understand the molecular behavior in aqueous systems at constant temperature and pressure. In this work we review the performance of some popular force fields, namely TraPPE, OPLS-AA and Gromos, in reproducing the experimental Gibbs energies of hydration of several alkyl-aromatic compounds-benzene, mono-, di- and tri-substituted alkylbenzenes-using molecular simulation techniques. In the second part of the paper, we report a new model that is able to improve such hydration energy predictions, based on Lennard Jones parameters from the recent TraPPE-EH force field and atomic partial charges obtained from natural population analysis of density functional theory calculations. We apply a scaling factor determined by fitting the experimental hydration energy of only two solutes, and then present a simple rule to generate atomic partial charges for different substituted alkyl-aromatics. This rule has the added advantages of eliminating the unnecessary assumption of fixed charge on every substituted carbon atom and providing a simple guideline for extrapolating the charge assignment to any multi-substituted alkyl-aromatic molecule. The point charges derived here yield excellent predictions of experimental Gibbs energies of hydration, with an overall absolute average deviation of less than 0.6 kJ mol(-1). This new parameter set can also give good predictive performance for other thermodynamic properties and liquid structural information
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