1,721,071 research outputs found
Stretchable screen-printed PEDOT:PSS electrodes for upper-arm surface electromyography
No full textIn the past ten years, wearable electronics underwent tremendous growth. Undoubtedly, one of the fields that led this trend is represented by biomedical applications. In this field, wearable technologies can provide unique features such as the unobtrusive monitoring of biopotentials. Polymerbased electrodes developed for this purpose can take advantage of their seamless integration in the garments. However, the available solutions exhibit fragility in relation with the stretchability of the fabric, causing significant performance degradation.In this work, this problem is tackled by a novel deposition approach based on screen-printing technology. The electrodes are deposited onto the pre-stretched fabric to ensure the full functionality during common operating conditions. To this aim, a novel PEDOT:PSS conductive ink formulation and printing procedure were conceived. In order to prove the electrode performance for surface electromyography, we printed the electrodes directly onto a commercial stretchable polyester sleeve for sport applications. The electrodes allowed to reliably record the muscular activity of the forearm with performance comparable to that of commercial gelled Ag/AgCl electrodes. The obtained results suggest that the proposed approach can be valuably used in health and fitness applications
Extraction Algorithm for Morphologically Preserved Non-Invasive Multi-Channel Fetal ECG
No full textNon-invasive fetal ECG (fECG) is a promising technique that could allow low-cost and risk-free diagnosis, and long-term monitoring of fetal cardiac wellbeing. However, the low quality of the fECG extracted from non-invasive abdominal recordings hampers its adoption in clinical practice. In this work, a new algorithm for the recovery of clean and morphologically preserved fECG signals from multi-channel trans-abdominal recordings is presented. The proposed method exploits optimal shrinkage and nonlocal median algorithms, along with a de-shape short-time Fourier transform-based detection, to recover high-quality fECG traces from a morphological perspective, while ensuring very high performance also in terms of fetal QRS detection. On a small dataset, composed of three real 20 min-long four-channel abdominal ECG recordings, a preliminary performance assessment of the proposed fECG extraction method in terms of fetal QRS detection capabilities revealed a median accuracy of 95.8% and F1 score of 97.9%. The obtained results suggest the possibility of successfully applying this approach for an effective non-invasive fECG extraction, deserving further investigations on larger real and synthetic datasets
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
Hybrid switching techniques for heterogeneous traffic support in multi-processors system on chip and massively parallel processors
No full textMulti-Processors System on Chip (MPSoCs) and Massively Parallel Processors (MPPs) architectures are conceived to efficiently implement Thread Level Parallelism, a common characteristic of modern software applications targeted by embedded systems. Each core in a MPP environment is designed to execute a particular instructions flow, known as thread, in a completely self-sufficient manner, being able to communicate with the other cores in order to exchange shared data. The demand of parallelism in MPPs and MPSoCs entails the design of an efficient communication layer able to sustain it. This means that the interconnection medium has to be both scalable, to allow multiple accesses of the different cores to the shared resources, and optimized in terms of wiring. These are all native characteristics of Networks on Chip (NoCs).
In MPSoCs and MPPs, it is necessary to provide:
- a quick resolution of the interdependencies among different threads, single scalar data or even vectors. Interdependencies are responsible of completion time delay because prevent a thread from completion when not resolved;
- load balancing support techniques to avoid hot spots and to efficiently exploit all the cores available on chip. When threads migration occurs, a regular and continuous traffic is generated, made up of long streams of data;
- management of end-to-end small control data.
Circuit Switching (CS) technique is the method by which a dedicated path, or circuit, is established prior the sending of the sensitive data. Circuit switched networks are suitable for guaranteed throughput applications, especially in case of real time communications.
In Packet Switching (PS) methodologies the intermediate routers are responsible for routing the individual packets through the network, neither following a predefined nor a reserved path. Packet switched networks are suitable for best-effort services or for soft-timing constrained communications.
In this chapter we will look at the possibility of combining CS and PS in order to support the heterogeneous traffic patterns coexisting in a MPP environment. Hybrid switching networks are designed to guarantee the benefits of both CS and PS consisting in a better usage of the available bandwidth and in a global increase of the overall throughput, at the price of a more complex hardware implementation. In this scope, the latest approaches in literature are presented, together with a particular NoC model able to provide dual-mode hybrid switching in a non-exclusive way, intended as the possibility of co-sharing the amount of available bandwidth between CS and PS communications
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
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