1,721,162 research outputs found
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
VR as innovation in dental education: Validation of a virtual reality environment: collecting evidence ‘on-the-fly’ during development and implementation
Full text linkWithin the dental curriculum there is an increasing need to solve scarcity in educational materials, such as extracted human teeth with the appropriate pathology and patients with dental treatment needs that match the students’ practicing goals to graduate as a competent dentist. A solution to aforementioned challenges has been sought in Virtual Reality and thus an innovation process has begun. With the development of the Moog Simodont dental trainer, a technological innovation for dental education was introduced. This dental trainer is a virtual reality learning environment in which the user is fully emerged into the virtual world enabling treatment of virtual patients and the performance of manual dexterity exercises. This thesis describes the creation and appreciation of the developed virtual teeth for use in the Simodont dental trainer to enable treatment of virtual patients. Additionally, it describes the evaluation and validation of assumptions made prior to the development of the Simodont dental trainer. Evaluation of the performance and user preferences revealed that three-dimensional vision has significant positive effects on performance and was identified as highly preferable among students compared to two-dimensional vision. Also the presence of force feedback in the dental trainer appears necessary to be able to perform an assignment that requires fine motor skills. Finally, the ‘on-the-fly’ approach which was used to create the above mentioned evidence, describes the process of innovation, implementation and collection of scientific evidence in an academic environment, during an ongoing curriculum
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
Interactions between root canal irrigants, sealers and dentin
Full text linkThe objective of this thesis was to determine the interactions between root filling materials and root dentin and to investigate if root canal irrigating solutions had an impact on these interactions. The following outcomes were assessed in the studies encompassed in this thesis: (i) dislocation resistance of an epoxy resin based root canal sealer and tricalcium silicate based root canal sealers, (ii) the influence of irrigation protocols on the sealing ability and chemical interactions with dentin of an epoxy resin based sealer, (iii) retreatability of mineral trioxide aggregate based sealers, (iv) characterization of a mineral trioxide aggregate based sealer following exposure to irrigation regimens. The results showed that irrigation protocols differentially influenced the sealer materials. The use of continuous chelation (sodium hypochlorite + etidronic acid) enhanced the bond strength of epoxy resin as well as mineral trioxide aggregate based sealers. This irrigation regimen also positively influenced the hydration characteristics of the tricalcium silicate materials. The bond strength of tricalcium silicate sealers improved with time. The epoxy resin sealer AH Plus chemically bonds to root dentin and irrigation protocols employing a final rinse of a proteolytic irrigant reduced the bond strength. Use of a final rinse of EDTA after continuous chelation significantly improved the bond strength of the epoxy resin sealer. Retreatability of mineral trioxide aggregate based sealers depends on the composition of the material with sealers containing a resin component being easily removable than compositions with without a resin
Diagnosis and decision making in endodontics with the use of cone beam computed tomography
Full text linkIn the current thesis the use of cone beam computed tomography (CBCT) in endodontics has been evaluated within the framework of ex vivo and in vivo studies. The first objective of the thesis was to examine whether CBCT scans can be used for the detection of vertical root fractures in endodontically treated teeth. The results of two ex vivo and one in vivo studies support the use of CBCT scans for the detection of vertical root fractures in endodontically treated teeth. They also suggest that the reproducibility and accuracy in vertical root fracture detection depend on the CBCT system used. The second objective was to follow the volumetric changes of periapical radiolucencies in endodontically treated teeth one year after orthograde retreatment with the use of CBCT scans. The volume of periapical radiolucencies reduced in 57% teeth, remained unchanged in 23% and increased in 20%. The third objective was to compare the precision of root canal length measurement on CBCT scans and periapical radiographs and to examine the influence of tooth type on these measurements. Root canal length measurements of posterior maxillary teeth were more accurate on CBCT images than periapical radiographs. The present thesis does not suggest that CBCT scans should replace the periapical radiographs for every endodontic patient. It rather emphasizes the need for careful patient selection together with the most suitable CBCT system and settings. Furthermore, it points out the importance of making the best use of available pre-existing CBCT scans before a patient is treated
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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