1,720,971 research outputs found
Preliminary Analisys on the Effect of Skin Temperature on Photoplethysmographic Signal
No full textPhotoplethysmographic sensors represent a promising wearable technology as combines its advantages in costs and weight with a wide variety of cardiovascular parameters which can be detected. Despite their potential, the accuracy of heart rate and blood oxygenation measures are affected by several influencing parameters, including the skin temperature. Thus, a multiwavelength PPG sensor was tested in a cohort of 20 subjects to assess the influence of the external temperature in the measurements of heart rate. The performance of the PPG sensor was tested for 5 different temperatures (i.e. 15, 20, 25, 30 and 35°C) at two different measurement sites (at the tip of the finger and at the wrist). Data were subsequently analysed in Matlab and compared with those of a reference ECG-based chest-band. Preliminary results showed that the accuracy of the PPG sensor increases with temperature; specifically, the blue and green wavelengths showed the best overall performances. Red light proved to be the most sensitive to temperature variations and showed the worst overall performance. Although results should be confirmed on a larger cohort of subjects, this study could contribute with a useful indication to enhance the accuracy of PPG-based wearable devices
Design of an open-lab activity for engineering students: A case study
No full textProject- or discovery-based learning activities promote curiosity, enjoyment, and interest deriving from the stimulating context in which students operate. Providing a concrete contextualization of laboratory activities could improve student motivation and learning outcomes. In this contribution, a case study related to a workshop on laboratory activities proposed for Engineering Master students is presented, and designed with the aim of developing practical competencies, increasing problem-solving skills, and providing design abilities. Using the facilities available in the Measurements and Control Laboratory, the students, starting from concept knowledge acquired in basic subjects, such as Physics, Chemistry, Mathematics, and Electronics, design and implement their experiments, gaining a deeper understanding of core disciplinary concepts while strengthening soft and teamwork skills. The challenges and possibilities of these self-directed thinking and learning laboratory activities are also discussed
Sensor-Based Bioprosthetic Valve Monitoring: Numerical Simulation and Experimental Design
No full textTranscatheter aortic valve implantation (TAVI) was developed to treat adult patients, but the progressive deterioration of biological valve leaflets poses challenges for extending TAVI to younger individuals. This study aims to develop a computational and experimental approach to design photoplethysmography (PPG) sensor for monitoring transcatheter heart valve (THV) performance. Fluid-solid interaction analysis is conducted on an idealized aortic vessel after virtual deployment of the SAPIEN 3 Ultra (S3) device. Numerical findings are compared with in-vitro data using a 3D-printed aortic phantom in a mock loop system. Computational flow data are then used for developing an analytical estimate of PPG signals, compared against experimental results from in vitro testing. Results show good agreement between analytical and experimental data, with a relative error on the pulse transient of 7.7%. Investigation into sensor positioning reveals placing sensors upstream and downstream of the bioprosthesis effectively assesses pressure gradients across the valve, aiding in developing an affordable monitoring system for detecting valve deterioration
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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