1,721,041 research outputs found
Hyperproliferation and genetic instability in cervical lesions
Full text linkContains fulltext :
144810.pdf (Publisher’s version ) (Open Access)Katholieke Universiteit Nijmegen, 08 november 2000Promotores : Ruiter, D.J., Boonstra, H. Co-promotores : Hanselaar, A.G.J.M., Wilde, P.C.M. de153 p
Design of an ultra deep water drillship with crude oil storage capacity type I
No full textMechanical, Maritime and Materials EngineeringMarine and Transport TechnologyShip Design, Production and OperationOvS 98/1
Durable Reliability of Jack-up Platforms. The impact of Fatigue, Fracture and Effect of Extreme Environmental Loads on the Structural Reliability
No full textA variety of factors is governing the operational conditions of jack-up platforms. The platforms are moved to different locations, which are causing changes in water depth, environmental and seabed conditions, drilling depths, payload etc. Insight should be gained in how the different factors affect the lifetime in order to be able to make a reliable prediction of the safety. The structure of the jack-up platform, usually consisting of three legs, which are supporting the platform containing living quarters, installations for power generation, machinery and equipment for drilling or production facilities, differs from a fixed platform. Aspects as the need for more flexibility and the development of marginal fields, initiate also a trend for jack-up platforms to operate in deeper water. The subject of this research project is durable reliability of jack-up platforms with the aim to explore the possibilities for the extension of the life-time. Aspects as fatigue, fracture and failure due to extreme environmental loads are investigated. The uncertainties in loads, material characteristics and structural modelling are investigated. A deterministic approach cannot properly take these uncertainties into account. For the reliability calculations, a method, based on refined stress states, is presented. The fracture mode is of importance when extreme environmental loads are combined with an existing crack in a structural element, which may be due to the fabrication process or fatigue. To estimate the statistical information about the crack a method based on the Monte Carlo simulation technique is presented. This method uses a fatigue crack growth formulation to specify the crack size. For the ultimate failure mode under extreme environmental loads the axial and bending stresses are combined to establish the time history of the usage factor. Due to the redundancy of the structure the system effect may be important. For this purpose a method is presented to specify the limit state function for sequences of failure leading to structural collapse and the failure probabilities of these sequences are calculated. The branch and bound technique is used to establish the branch tree to identify the important failure sequences. Then the system failure probability is calculated by combining the most important sequences leading to structural collapse. For this purpose The First Order Multi Normal approach (FOMN) and bound techniques are used. For a case study, the 'Neka' platforms which was chosen in this thesis, the failure probability of the structural system in the combination of fracture and fatigue failure modes proved to be the most important. The results show significant system effects. The conclusion may be drawn that this type of structural failure deserves significant attention during the ageing of jack-up platforms. This research work does not claim to have solved all issues related to the structural reliability of a jack-up platform. However, a number of valuable stepping-stones have been developed as a basis for further research.Design, Engineering and Productio
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
Concept Exploiration Model for Bulk Carriers
No full textMechanical, Maritime and Materials EngineeringMarine and Transport TechnologyShip Design, Production and OperationOvS 00/0
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
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