1,720,976 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
Signalized Turbo Roundabouts: A Study into the Applicability of Traffic Signals on Turbo Roundabouts
No full textSince the 1980s, the modern single-lane roundabout has been applied in the Dutch road network. The roundabout offered major safety benefits compared to the conventional signalized intersection, however, it also required more space. Influenced by society’s growing mobility, the capacity requirements to intersections increased. This quest for capacity gave rise to the concentric multi-lane roundabout: a roundabout with two or more circulatory lanes and one or more lanes on the entrance and exit legs. The concentric multi-lane roundabout offered a higher capacity, but compromised the safety benefits of the single-lane roundabout. As an answer to the safety problems on the multilane concentric roundabout, Fortuijn developed the turbo roundabout in 1996. The turbo roundabout offers the same safety level as the single-lane roundabout and a higher capacity. Nowadays, the quest for a higher capacity continues unabated. This graduation project aims to contribute to the quest by investigating the combination of turbo roundabouts and traffic lights. The central question is whether traffic signals enhance the capacity of the turbo roundabout. The two largest turbo roundabout types have been investigated: the rotor roundabout (four-leg) and the star roundabout (three-leg). Three models (the MSRV, an analytical approach and VISSIM) have been applied to evaluate the capacity of the rotor and star roundabout (signalized and un-signalized). In addition, this project states proposals for future research into other performance indicators than the capacity; namely space requirement, delay time, robustness, traffic safety and environmental issues. This research shows that the signalized turbo roundabout only allows for a leg-by-leg control. However, the lane configuration on the rotor and star roundabout can be adjusted such, that the turbo roundabout is suitable for the more efficient two-phase control, which is currently being applied to the turbo circle. The results are the partial turbo circle (adjusted rotor roundabout) and the three-leg turbo circle (adjusted star roundabout). The latter intersection types require more space than the rotor and star roundabouts. The capacity evaluation shows that the partial turbo circle has no applicability range, because the capacity for left-turning traffic streams is very limited. The three-leg turbo circle has potential, because it offers a higher capacity than the star roundabout. The geometrical design of the signalized turbo roundabout allows for phase overlap within the leg-by-leg control. Thanks to the phase overlap, two subsequent legs can obtain green simultaneously for a period in the order of 1 to 8 seconds. Consequentially, the aggregated green time within one hour can be extended compared to the leg-by-leg control without any phase overlap, enhancing the capacity of the turbo roundabout. The capacity of the signalized turbo roundabout has been evaluated analytically by means of the analytical approach, which was developed by Fortuijn simultaneously with the development of the turbo roundabout. The analytical approach calculates the capacity by multiplying the green time per hour with the saturation flow. The capacity of the signalized rotor roundabout ranges from 2800 pcu/h to 3700 pcu/h; the capacity of the signalized star roundabout ranges from 4400 pcu/h to 5200 pcu/h, depending on the demand pattern. Using the green phase overlap, the rotor roundabout may offer 5% to 6% more capacity; the star roundabout may offer 7% to 9% more capacity. Moreover, the microscopic simulation tool VISSIM has been applied to evaluate the capacity of and delay time on the signalized turbo roundabout and the (partial and three-leg) turbo circle. The capacity results of the analytical approach and VISSIM do not differ much, except for the results for the star roundabout with an inscribed radius of 20 m. No explanation has been found. In order to compare the capacities of the signalized and the un-signalized turbo roundabouts, the capacity of the un-signalized turbo roundabout has been evaluated by means of the Meerstrooksrotondeverkenner (Multilane roundabout explorer). The un-signalized rotor roundabout offers a capacity ranging from 2900 pcu/h to 4500 pcu/h. The signalized rotor roundabout offers a lower capacity; this intersection type is not recommendatory for application. The same conclusion holds for the partial turbo circle, however, the partial turbo circle offers a higher capacity in situations with low left-turning intensities (in the range of 20% of the straight-ahead intensities). The turbo circle offers a much higher capacity than the (un-)signalized rotor roundabout (ranging from 4700 pcu/h to 9300 pcu/h, depending on diameter and demand pattern), but requires more space. With regard to the three-leg intersections: the capacity of the signalized star roundabout (ranging from 4400 pcu/h to 5200 pcu/h) is larger than the capacity of the un-signalized star roundabout (ranging from 3700 to 5100 pcu/h). However, the signalized star roundabout induces longer delay times (nearly twice as long), and probably less traffic safety and higher environmental burdens. The three-leg turbo circle offers an even higher capacity than the signalized star roundabout (ranging from 5400 pcu/h to 7100 pcu/h), but requires more space. From this study, it can be recommended to pay further attention to the signalized star roundabout and the smaller three-leg turbo roundabouts (both in scientific research as well as in practical engineering), because the signalized star roundabout has a larger capacity than the un-signalized star roundabout. The signalized rotor roundabout and the partial turbo circle are not recommendatory for further research, because the un-signalized rotor roundabout offers a higher capacity.Traffic Flow TheoryTransport & PlanningCivil Engineering and Geoscience
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
Perspectief of uitzichtloos?
No full textDe scriptie die voor u ligt beschrijft de zoektocht het functioneren van het instrument marktconsultatie
bij gebiedsontwikkeling gerelateerd aan de motivatie van private partijen om hieraan deel te nemen en
de bereidheid om hier in de toekomst aan deel te blíjven nemen. Deze zoektocht is ontstaan uit eigen
ervaringen met de marktconsultatie als projectontwikkelaar bij zo’n private partij. Tijdens het proces
van deze marktconsultatie kwamen er allerlei vragen boven over waarom private partijen eigenlijk
deelnemen aan een marktconsultatie. Er wordt over het algemeen veel tijd, geld en energie in gestoken en
de marktconsultatie eindigt in een bedankje van de gemeente voor de geleverde inspanningen en ieder
gaat weer zijns weegs, de private partijen toch enigszins gedesillusioneerd achterlatend. Deze ervaring
combineerde ik met de colleges tijdens de MCD opleiding over PPS, integrale gebiedsontwikkeling, Europese
aanbestedingsregels, de instrumenten welke gebruikt kunnen worden in het proces- en projectmanagement,
allemaal binnen de context van de gebiedsontwikkeling. Ook de overgang van toelatingsplanologie naar
ontwikkelingsplanologie speelde, waarbij de voorwaartse integratie van de private partijen in het proces
van de ruimtelijke ordening een belangrijke plaats inneemt. De steeds vroegere betrokkenheid van de
private partijen in het proces van de gebiedsontwikkeling waarbij uitwisseling van en het gebruik maken
van elkaars kennis en expertise centraal staat vond ik een heel interessant gegeven, zeker gerelateerd aan
het instrument marktconsultatie. Dit was tenslotte een instrument waarbij er al in een zeer pril stadium van
een project of opgave kennis uitgewisseld werd tussen publiek en privaat. Of was het puur vanuít de private
partij naar de publieke partij. Daarbij kwam dat de Reiswijzer Marktpartijen & Gebiedsontwikkeling net uit
was, waar ook veel over gesproken is, zowel tijdens de studie als op het werk. Al deze ervaringen en indrukken
gecombineerd hebben geleid tot mijn scriptie, waarbij de vraag centraal staat onder welke condities private
partijen eigenlijk geïnteresseerd zijn en blijven in deelname aan de een marktconsultatie
- …
