1,720,969 research outputs found
Dynamic model of a power-to-gas system: Role of hydrogen storage and management strategies
No full textTackling climate change requires a drastic decarbonization of the energy system through the introduction of renewable energy technologies. However, a greater penetration of intermittent renewables requires large-scale flexible energy storage. This need, combined with the growing interest in the use of hydrogen in mobility and industry, makes tangible the prospect of including this energy vector in our daily lives. However, the problems related to the development of dedicated infrastructures make its positioning in the market complex. In a transition phase, power-to-gas systems constitute an emerging solution that allows the use of existing structures for natural gas and, at the same time, solves the problem of hydrogen storage. In this study, a power-to-gas system producing synthetic methane from wind energy was modeled. Management strategies for both the electrolysis system and the hydrogen storage were implemented. In particular, the impact of the storage on the mitigation of the operating condition fluctuation of the methanation unit was analyzed. To verify the influence of the sizing of the subsystems over the system performance, a sensitivity analysis on the sizes of the methanation unit and hydrogen storage was carried out. The conducted sensitivity analysis suggested selecting the smallest size of the hydrogen storage and the size of the methanation unit equal to 80% of the electrolysis system nominal production to achieve good performances of the power-to-gas system. However, the sizing of the subsystems depends on the context in which the power-to-gas system is integrated (i.e., characteristics of wind source), the possibility to valorize the hydrogen surplus (i.e., proximity to hydrogen users), and the specific objective for which the system has been designed
Exploring sensory alterations and repetitive behaviors in children with autism spectrum disorder from the perspective of artificial neural networks
No full textBackground: Restrictive repetitive behaviors (RRBs) and sensory processing disorders are core symptoms of autism spectrum disorder (ASD). Their relationship is reported, but existing data are conflicting as to whether they are related but distinct, or different aspects of the same phenomenon. Aims: This study investigates this relationship using artificial neural networks (ANN) analysis and an innovative data mining analysis known as Auto Contractive Map (Auto-CM), which allows to discover hidden trends and associations among complex networks of variables (e.g. biological systems). Methods and procedures: The Short Sensory Profile and the Repetitive Behavior Scale-Revised were administered to 45 ASD children's caregivers (M 78 %; F 22 %; mean age 6 years). Questionnaires' scores, clinical and demographic data were collected and analyzed applying Auto-CM, and a connectivity map was drawn. Outcomes and results: The main associations shown by the resulting maps confirm the known relationship between RBBs and sensory abnormalities, and support the existence of sensory phenotypes, and important links between RRBs and sleep disturbance in ASD. Conclusions and implications: Our study demonstrates the usefulness of ANNs application and its easy handling to research RBBs and sensory abnormalities in ASD, with the aim to achieve better individualized rehabilitation technique and improve early diagnosis. Paper's contribution: Restricted, repetitive patterns of behaviors and interests and alteration of sensory elaboration are core symptoms of ASD; their impact on patients' quality of life is known. This study introduces two main novelties: 1) the simultaneous and comparative use of two parent questionnaires (SSP and RBS-R) utilized for RRBs and alteration of sensory profile; 2) the application of ANNs to this kind of research. ANNs are adaptive models particularly suited for solving non-linear problems. While they have been widely used in the medical field, they have not been applied yet to the analysis of RRBs and sensory abnormalities in general, much less in children with ASD. The application of Auto Contractive Map (Auto-CM), a fourth generation ANNs analysis, to a dataset previously explored using classical statistical models, confirmed and expanded the associations emerged between SSP and RBS-R subscales and demographic-clinical variables. In particular, the Low Energy subscale has proven to be the central hub of the system; interesting links have emerged between the subscale Self-Injurious Behaviors and the variable intellectual disability and between sleep disturbance and various RRBs. Expanding research in this area aims to guide and modulate an emerging targeted and personalized rehabilitation therapy
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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