1,723,061 research outputs found
Determination of the main parameters affecting the performance of bridge falsework systems
Full text linkBridge falsework systems are one of the most common temporary structures used in the
construction industry, namely to support the formwork during the construction, rehabilitation or
retrofit works of concrete bridges and viaducts.
This Thesis presents new results and research that improve the available knowledge about the
structural behaviour, reliability, robustness and risk of these structures. The main, internal and
external, hazards are identified and detailed, including the procedural, enabling and triggering
hazards. The use of reduction factors to determine the values of the applied loads to design bridge
falsework, and other temporary structures, is critically analysed and it is recommended not to use
them, unless supported by specific site data. The importance of implementing effective quality
control, inspection and communication measures to manage human errors during planning,
designing and operation is highlighted.
From the 192 tests carried out during the experimental campaign, consisting of five different
tests using three different joint types, new results are obtained concerning bridge falsework
components, namely the bending behaviour and resistance of spigot joints and forkhead joints
(falsework to formwork interface) from which no published research was found. Existing joint
models are evaluated and improved alternative models are developed.
The results of numerical studies of a selected structural system are presented using a novel joint
finite element and information gathered from the experimental tests. This new finite element has
features that the available elements in ABAQUS® program do not have, specifically the capability of
simulating an analytical modelling of the cyclic behaviour of joints with allowance for stiffness and
resistance degradation and joint failure. The accuracy and precision of the developed numerical
models improves the existing numerical results of full-scale tests of bridge falsework systems, in
respect to structural behaviour and resistance. It is recommended that formwork should be
explicitly modelled and modelling of spigot joints should follow the model presented in this Thesis.
From a sensitivity analysis of the bridge falsework systems to modelling hypothesis, it is found that
the most important joints are the beam-to-column joint, followed by the forkhead joint and the spigot
joint, with variations of up to 70% between the resistance of the system when the joints are modelled
as continuous or as pinned.
A key contribution of the Thesis is to introduce a novel risk management methodology based on
newly developed robustness and fragility indices. This new methodology is applicable, in principle, to all
structural analyses not only those concerning bridge falsework systems. Based on advanced
deterministic studies, the main parameters affecting the performance of bridge falsework are identified,
analysed and discussed. These studies involved a comprehensive set of external and internal hazards:
(i) applied external actions of different nature and (ii) structural configurations to design bridge falsework.
It is found that differential ground settlements are a critical action and that stiffer systems are more
sensitive. Also, it is highlighted by use of plenty examples that bracing is an essential design requirement.
Advanced stochastic investigations are also carried out, in which the key random variables that
control the stochastic behaviour of bridge falsework systems are identified, namely joint looseness
and initial stiffness after looseness. Possible strategies to increase robustness and decrease fragility
are discussed and based on an application example the cost-benefit of alternative solutions is
investigated. It is concluded that implementing quality control and quality assurance procedures to
bridge falsework elements is an extremely effective and efficient way of reducing existing risks.
The information gathered in this Thesis can be used to develop more rational and reliable bridge
falsework structures thus safer and more design efficient
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
Architectural studies for visual processing / Andre J. S. Yakovleff.
Full text linkBibliography: p. 165-184.xvi, 184 p. : ill. ; 30 cm.This thesis explores the issue of copying natural vision processes with regard to providing sensing information in real-time to the lowest control levels of an autonomous vehicle. It is argued that the interpretation of sensory data should result in a level of perception which is tailored to the requirements of the control system.Thesis (Ph.D.)--University of Adelaide, Dept. of Electrical and Electronic Engineering, 1996
Alien Registration- Gouin, Andre J. (Sanford, York County)
Full text linkhttps://digitalmaine.com/alien_docs/3608/thumbnail.jp
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
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