1,721,016 research outputs found
Modelling of maintenance data
No full textThe modelling of maintenance data starts with the black-box approach (where the model selection is based solely on the maintenance data) and then through the grey-box approach for proper analysis (where one can gain insights to build better models). These models allow for more effective maintenance of the object. This paper deals with the grey-box approach to modelling. It discusses the process of modelling and illustrates this through a real case study
Integrated RAMS, LCC and Risk Assessment for Maintenance Planning for Railways
No full textAs of today, about 70% of the transportation infrastructure has already built for the needs of customers, business and society, where Railways is the major infrastructure. Due to huge investment for renewal and overhaul, there is emergent need to maintain the infrastructure with high availability with minimum cost and risk, being, transportation is the backbone of the economy. These infrastructures normally lead to degradation due to operational loads, environmental factors and frequent interventions. Hence, planning and optimization of the maintenance actions with the constrained resources is implemented properly for the efficient operation. Due to the hierarchical nature of Railways, there is necessary for railway infrastructure managers to design a generic framework for the decision-making process when planning maintenance and interventions, which is an important functional block of asset management in railway infrastructures. This chapter proposes an integrated methodology to perform maintenance decision making using definitive “building blocks” namely Reliability, Availability, Maintainability and Safety (RAMS), Life Cycle Costing (LCC) and Risk assessment. It has to incorporates the “building blocks” at different planning levels in asset hierarchy; namely network, route, line and component and planning hierarchy; namely Strategic Asset Management Plan (SAMP), Route Asset Plan (RAP), Route Delivery Plan (RDP) and Implementation of Asset Maintenance Plan (IAMP) as proposed in IN2SMART which was renamed from ISO 55000 Asset Management Framework.</p
Advances in RAMS Engineering : In Honor of Professor Ajit Kumar Verma on His 60th Birthday
No full textThis book surveys reliability, availability, maintainability and safety (RAMS) analyses of various engineering systems. It highlights their role throughout the lifecycle of engineering systems and explains how RAMS activities contribute to their efficient and economic design and operation.The book discusses a variety of examples and applications of RAMS analysis, including:• software products;• electrical and electronic engineering systems;• mechanical engineering systems;• nuclear power plants;• chemical and process plants and• railway systems.The wide-ranging nature of the applications discussed highlights the multidisciplinary nature of complex engineering systems. The book provides a quick reference to the latest advances and terminology in various engineering fields, assisting students and researchers in the areas of reliability, availability, maintainability, and safety engineering.</p
Reliability Considerations in Analysis of Tunnels in Squeezing Rock
No full textAdvances in RAMS Engineering pp 237–257Cite asReliability Considerations in Analysis of Tunnels in Squeezing RockDownload book PDFDownload book EPUBReliability Considerations in Analysis of Tunnels in Squeezing RockG. Venkatachalam, Mallika Sreedharan & A. Srividya ChapterFirst Online: 11 December 2019492 AccessesPart of the Springer Series in Reliability Engineering book series (RELIABILITY)AbstractUnderground openings and excavations are increasingly being used for civilian and strategic purposes all over the world.Access provided by Lulea University of Technology LibraryUnderground openings and excavations are increasingly being used for civilian and strategic purposes all over the world. Pressure on tunnel support depends on deformation and stress release and tunnels can be classified [9] into: (a) conforming; (b) non-conforming. Evaluation of safety of a tunnel, especially a non-conforming one, in soft ground or poor rock mass needs an interactive analysis. Interaction is an issue of great relevance in the case of tunnels in lower Himalayas. Many valuable field observations on actual Himalayan tunnels have been documented by [2, 7, 8]. Based on these, several empirical correlations have been developed, which are very useful in evaluating, particularly, the rock pressure on such tunnels. Although the correlations account for a wide variety of ground conditions, there is, inevitably, considerable empiricism. Jimenez and Recio [3] have attempted a probabilistic modelling of the variable ground conditions and evolved classifiers to distinguish between squeezing and non-squeezing conditions. However, evaluating the response of tunnels considering the material uncertainties has not been included in their scope. The present study is an attempt to evaluate tunnel safety and stability through reliability analysis under squeezing conditions.</p
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
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
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