1,720,997 research outputs found
Estimation of Heat Release and In-Cylinder Pressure in Diesel Engines from Basic Testbed Data
Full text linkThe present paper proposes a novel approach for the estimation of the in-cylinder pressure and heat release in diesel engines from basic testbed measurements (i.e., brake mean effective pressure (BMEP), gross indicated mean effective pressure (IMEP360), peak firing pressure (PFP), crank angle at which 50% of fuel mass has burnt (MFB50) and exhaust gas temperature (Texh). The method exploits a previously developed low-throughput combustion model, based on the accumulated fuel mass approach, which has been tuned by a genetic algorithm (GA) optimizer. The latter adjusts the main combustion model parameters to minimize an objective function, which depends on the prediction errors of BMEP, IMEP360, PFP, MFB50 and Texh. Several scenarios were evaluated in which different subsets of the four previous quantities were assumed to be known from experimental activities. The proposed method is particularly useful when in-cylinder pressure traces are unavailable and only basic testbed data exist. The results show that the in-cylinder pressure and heat release profiles are estimated with a high level of accuracy, since the root mean squared error is of the order of 1–2.5 bar and 2–2.7 × 10−2 kJ, respectively, depending on the considered scenario, while requiring a modest computational effort which is of the order of 3–6 min per test. Moreover, the low-throughput nature of the method makes it straightforward for other researchers to implement and reproduce results on different engines. The approach is also fuel-independent and can be applied to engines running on alternative/zero-carbon fuels, which are currently being extensively studied as potential ways to reduce the environmental impact of internal combustion engines
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
Preparazione dell'anestesia endovenosa bilanciata mediante medicazione preanestetica attuata in due tempi per via intramuscolare ed endovenosa
No full textGli autori,dopo aver ricordato l'importanza della medicazione preanestetica per la sedazione dei pazienti e per l'esecuzione di una corretta anestesia generale, espongono i risultati ottenuti con un tipo di M.P. analgesica e sedativa somministrata in parte i.m. ed in parte per via e.v. utilizzando la meperidina i.m. e tre diverse benzodiazepine e.v
Effects of judo training on bones: A systematic literature review
No full textThe aim of this study was to provide a systematic literature review on the osteogenic effects of judo (PROSPERO: CRD42016041803). The online search was conducted according to the inclusion criteria: observational studies and clinical/interventional trials in English from inception to June 2016; bone health, bone mineral density (BMD), diameters, impact force, and bone turnover marker (BTM) outcomes. Thirty-four studies were included and graded for their methodological quality ("fair" quality: 79.4%). The most used assessment method (44.1%) was X-ray absorptiometry. A positive association between judo and bone health/status emerged. Findings support site-specific BMD accrual in children, adolescents, adult athletes, and in premenopausal and postmenopausal female practitioners. Bone turnover markers revealed a hypermetabolic status in high-level judo athletes. The osteogenic stimuli of judo seem to protect athletes from alterations in bone metabolic balance due to weight loss cycling. Sexual dimorphism was found between judoka in bone diameters and mass, and significant differences in bone breadths emerged between elite and nonelite judokas. The fall techniques reduced bone impact force and velocity with respect to "natural" fall. Further longitudinal, cross-sectional, and interventional researches are required. This article provides useful information on bone for health sport scientists, coaches, and practitioners, stimulating future research lines on judo. In particular, coaches and physical trainers should consider introducing judo fall techniques in their training plans to prevent fall-related injuries, especially relevant in the older population. Conversely, coaches are urged to carefully control weight cycling dietary habits of their athletes, which can produce serious metabolic responses on bones
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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