Annika Sorg and Manfred Bischoff
The purpose of this paper is to develop a method to model entire structures on a large scale, at the same time taking into account localized non-linear phenomena of the discrete…
Abstract
Purpose
The purpose of this paper is to develop a method to model entire structures on a large scale, at the same time taking into account localized non-linear phenomena of the discrete microstructure of cohesive-frictional materials.
Design/methodology/approach
Finite element (FEM) based continuum methods are generally considered appropriate as long as solutions are smooth. However, when discontinuities like cracks and fragmentation appear and evolve, application of models that take into account (evolving) microstructures may be advantageous. One popular model to simulate behavior of cohesive-frictional materials is the discrete element method (DEM). However, even if the microscale is close to the macroscale, DEMs are computationally expensive and can only be applied to relatively small specimen sizes and time intervals. Hence, a method is desirable that combines efficiency of FEM with accuracy of DEM by adaptively switching from the continuous to the discrete model where necessary.
Findings
An existing method which allows smooth transition between discrete and continuous models is the quasicontinuum method, developed in the field of atomistic simulations. It is taken as a starting point and its concepts are extended to applications in structural mechanics in this paper. The kinematics in the method presented herein is obtained from FEM whereas DEM yields the constitutive behavior. With respect to the constitutive law, three levels of resolution – continuous, intermediate and discrete – are introduced.
Originality/value
The overall concept combines model adaptation with adaptive mesh refinement with the aim to obtain a most efficient and accurate solution.
Details
Keywords
Koraljka Golub and Daniel Ocic Ihrmark
Many end users turn to Google Books and social tagging services to identify books of interest. How successful they are will depend on subject indexing applied in these services…
Abstract
Purpose
Many end users turn to Google Books and social tagging services to identify books of interest. How successful they are will depend on subject indexing applied in these services (among other factors). The study aimed to determine: (1) to what degree are Queerlit books identified as LGBTQ+ books in widely used information services, in particular Google Books, LibraryThing and Goodreads; and, (2) whether metadata in these information services could be considered of value for the Queerlit database and complement its highly extensive and highly specific indexing.
Design/methodology/approach
The study compared keywords (subject index terms, tags) assigned to works of Swedish LGBTQ+ fiction across three commercial services: Google Books, Goodreads and LibraryThing, against the curated database, Queerlit.
Findings
Of the 1320 LGBTQ+ works in Queerlit, only a small portion was found in the three web services: 8.26% on Google Books (n = 109), 13.26% on Goodreads (n = 175), while about half on LibraryThing (55.3%, n = 730). This underrepresentation of Swedish LGBTQ+ works in the three international commercial information services makes them hardly of value to the readers. This is exacerbated by the fact that only a minority of Queerlit books found in the three services are categorised as LGBTQ+. The Queerlit database might benefit from consulting social tagging services when indexing both LGBTQ+ specific and general themes.
Originality/value
No earlier study compared in a systematic manner four different information retrieval systems and identified challenges as well as potential benefits in relation to finding LGBTQ+ fiction.