China
Africa
Explore chapters and articles related to this topic
Risk Based Maintenance for Civil Structures
Published in Jaap Bakker, Dan M. Frangopol, Klaas van Breugel, Life-Cycle of Engineering Systems, 2017
B.R. Mante, N. Eekels, C.P.W.J. Genders
Failure mode analysis is used worldwide, for instance in the oil and gas industry. To determine a chance of failing, a system is decomposed into (often prefabricated, created in high volumes) components of which statistical information is known, like mean time to failure etc. Fixed civil structures, like bridges or viaducts, are mainly unique and built at the site. Therefore, analysis of the structures becomes more subjective and based on expert judgement. The consequence is that, for an individual risk, one can always argue that a chosen chance or effect category should be higher or lower. Sometimes there is no absolute ‘truth’. Therefore, we advise to combine competitor’s knowledge, at first in separate analysis of the same structures/(sub)systems within clear boundaries and then to evaluate, discuss and learn. Guided by an uninvolved, open-minded steering committee, this can help to create an ‘accepted’ set of agreements and perhaps assumptions as a foundation for a more standardized way of working.
Scope, Genres, and Audiences of SMC
Published in Scott A. Mogull, Scientific and Medical Communication, 2017
In SMC, communicators carefully use terms and present data that communicate the degree of certainty of the research findings. Most scientists believe that knowledge claims are not absolute, only supported or falsified. In addition, formal SMC that presents theories, particularly new theories, is saturated with careful presentation strategies (Reeves 2005) and hedging statements (Hyland 1996) that restrict and qualify the certainty of claims. For example, we see these strategies used in the first published account arguing that DNA was the molecule of heredity. Oswald Avery, Colin MacLeod, and Maclyn McCarty (1944) stated that “the experimental data presented in [their] paper strongly suggest [emphasis added] that nucleic acid, at least those of the desoyribose type, possess different specificities as evidenced by the selective action of the transforming principle” (152). Yet, over time as scientific theories mature, such careful presentation strategies are abandoned in lieu of more direct prose. For example in their paper presenting the structure of DNA, Watson and Crick (1953) stated, “It has not escaped our notice that the specific pairing we have postulated immediately suggest a possible copying mechanism for the genetic material [emphasis added]” (737). In this example, the new theory presented, the structure of DNA, is qualified but previous findings regarding the function of DNA are accepted without hedging terms and “the genetic material” is substituted for “DNA.” Despite the shift to an objective style for more accepted scientific theories, these careful strategies are usually not replaced by terms of absolute certainty, such as “fact.” Rather, according to the principles of science, scientific and medical findings are always subject to change or refinement—being contingent on data from future research. This is a particular problem in medical studies in which the validity of conclusions has been criticized for being overstated (Boutron et al. 2010; Ioannidis 2008).
An Introduction to Risk Assessment with a Nod to History
Published in Ted W. Simon, Environmental Risk Assessment, 2019
Truth is not absolute in science—a scientist may change his interpretation of conclusions based on new data or updated methods, and the scientific method is an iterative process used to learn about the world. Dr. Li has publicly stated that the Wall Street Journal article is false and demanded that it be retracted.159
Detection and Characterization of Bearing Faults from the Frequency Domain Features of Vibration
Published in IETE Journal of Research, 2018
P. Arun, S. Abraham Lincon, N. Prabhakaran
SF is the average variation of the spectral magnitude between two adjacent signal segments. To compute SF, the signal is divided to “M” segments each containing “N” samples. The SF between two adjacent signal segments “xm” and “xm−1” [34]where “Xm(k)” is the absolute spectrum of the mth segment given by,“ε” is a small constant used to avoid computational “indeterminacy”. The overall SF of the signal is the average of SF between adjacent segments