1,720,956 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Fish school search: an interval representation
Get PDFFish species compared to animals show complicated behavior mostly to increase their survivability. One may understand the phenomenon by two different ways viz., for mutual protection and for synergic achievements of other collective tasks. As per the literature, there exist some studies related to the above collective goals for finding food by considering the data as a crisp or exact form. But in actual practice the positions of fish at each instant of time may not be obtained in crisp. But those should be taken in uncertain form. Here this uncertainty has been taken in terms of interval. Hence in the thesis, a new form of fish school search has been proposed. Accordingly the interval computation has been implemented to obtain the fish position and hence the optimization process goes in a new direction
Development and Evaluation of Hot and Warm Sand-Sulphur-Bitumen Paving Mixes
No full textThe economic growth of a country leads to urban expansion and infrastructure development importantly in pavements, which eventually increases the demand for stone aggregates. The uncontrolled extraction of construction aggregates has resulted in severe depletion of existing natural stone reserves. Keeping this issue in mind, the use of locally available and waste materials as a substitute for stone aggregates, particularly in road construction has become a major research interest. Contemporarily, sand is available abundantly in some places, such as in coastal deltaic plains, beaches and desert areas. Hence, researches involving utilisation of sand as an alternative to coarse aggregates are worth taking up. In this direction, few studies reported sand-bitumen mix to be weak and unstable (low stability and high air void content), and hence unsuitable for pavement construction. However, the properties of sand-bitumen mix could be improved with inclusion of sulphur which is a by-product of coal processing, and petroleum and gas refining processes. When Sulphur is added as third material along with sand and bitumen, the mix is typically termed as sand-sulphur-bitumen (SSB) mix. This research work addresses the development and evaluation of SSB mixes in order to utilise locally available sand as an alternative to coarse aggregates for paving purposes. This study basically investigates two types of mixes namely, hot and warm SSB mixes. For preparation of hot mixes, VG 30 bitumen was used whereas for warm mixes, VG 30 bitumen was modified with sasobit so as to facilitate mixing and compaction at lower temperature. First of all, a suitable mixing method was developed to prepare SSB mixes that involved selection of critical mixing parameters such as mixing sequence, mixing temperature, mixing time and compaction effort. Concurrently, gaseous emissions were monitored to assess the potential hazards due to toxic gases released during mix preparation. Next, the effects of varying proportions of constituents such as sand, sulphur and bitumen were considered to determine the optimum mix compositions based on Marshall properties. Further, crusher dust in varying concentrations and/or various types of fillers such as fly ash, stone dust and cement were considered for the mix, and the Marshall properties were studied to determine the best proportions of ingredients. In addition to Marshall properties, the selected mixes were evaluated in terms of other performance characteristics such as indirect tensile strength, moisture susceptibility, resilient modulus, fatigue performance and rutting characteristics. Furthermore, an attempt was made to study the internal structure of SSB mixes with the help of effective and quick non-destructive 3D (three-dimensional) high resolution technology namely X-Ray micro computed tomography coupled with digital image analysis techniques. Various air void (AV) parameters such as volume, size and shape of voids, connected air void content, and tortuosity of compacted specimens were assessed to describe the geometric and topological properties of voids. The impacts of variation in the mix constituents on AV parameters were examined to understand their effects on void structure and their properties. Additionally, probabilistic analysis was performed to model the void size distributions in SSB mix specimens. The permeability of SSB mixes was also measured using an asphalt permeameter and correlation analysis was performed to establish the relationships between permeability and AV parameters. In addition, predictive models for permeability were developed based on the fundamental mix properties. Experimental results revealed that for hot SSB mixes, the optimum mixing sequence included mixing of VG 30 bitumen with sand-molten sulphur blend at 145°C, whereas for warm SSB mixes the mixing sequence involving mixing of molten sulphur with sand-modified binder at 125°C produced the best results. The gaseous emission analysis showed that the concentration levels of various harmful emissions near the place for SSB mix preparation (in the laboratory) were found to be much below the prescribed limits specified in different standards for hot SSB mixes. The emissions were found to be much less for warm SSB mixes. With regard to mix composition, the concentrations of sand and sulphur by weight of mix were found to be 85% and10% respectively for both hot and warm SSB mixes. Substantial improvements in Marshall properties were noticed with the replacement of sand by 30% crusher dust. For all filler types, optimal filler content was found to be 5% by weight of aggregate. For each mix type, bitumen contents of 4.5 and 5% by weight of each mix were chosen based on the Marshall test results. The SSB mixes with selected mix compositions were found to exhibit satisfactory performance characteristics. The microstructural characterisation of SSB mixes revealed that the mix constituents, mainly incorporation of crusher dust, had significant impacts on the AV parameters. A two-parameter loglogistic distribution and a four-parameter stable distribution were found to be the best fit models for void size distribution of hot and warm mixes respectively. Further, permeability of SSB mixes had significant correlations with the geometric and topological void properties. Despite having high air void content, the SSB mixes exhibited a high degree of impermeability which is attributed to the less connectivity of air voids and higher tortuosity of the mixes. Predictive models developed using neighbourhood component analysis (NCA) regression approach for prediction of permeability was found to be accurate (R2 = 0.99) for both hot and warm SSB mixes. Furthermore, the life cycle cost analysis of typical SSB mixes revealed that there is a substantial economic benefit as compared with conventional bituminous mixes. In summary, the SSB mixes exhibited essential performance characteristics as required for a normal bituminous pavement. Overall, this study showed an effective way to use SSB mixes as a bituminous layer with complete exclusion of conventional coarse aggregates which are scarce in some locations
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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