A common problem that arises in many applications in practice is to determine the subset (or 3 assortment) of items to offer to a user. We focus on the concrete setting in which a retailer must 4 decide the subset of products to offer to each arriving customer (either online or in a brick-and-mortar 5 store). The retailer chooses the subset from a large universe U of products with the objective...

The aim of the present study is to investigate the stability of crack propagation in cementitious materials. Tests were conducted on bend specimens in three-point and four-point loading conditions.Three-point bend specimens showed stable crack growth for mortar, normal strength and high strength concrete specimens. Alternatively, four-point bend specimens showed catastrophic failure for mortar ...

Method: At first, two optimized fineness levels were attained for both cement substituting materials used in this study (GGW as glass fine ˂ 38μm (GF), glass superfine ˂ 25μm (GSF) and EAFS as slag fine ˂ 75μm (SF), slag superfine ˂ 32μm (SSF)). In addition to control mortar (CM), four types of binary mortar mixtures were cast by substituting cement 5-20% with GGW (GF and GSF) and 10-30% with E...

The balancing domain decomposition method for mixed finite elements by Cowsar, Mandel, and Wheeler is extended to the case of mortar mixed finite elements on non-matching multiblock grids. The algorithm involves an iterative solution of a mortar interface problem with one local Dirichlet solve and one local Neumann solve per subdomain on each iteration. A coarse solve is used to guarantee that ...

Concrete is a heterogeneity material consisting of mortar and aggregate in meso scale. Evaluation of fracture process in this scale is useful to clarify the material characteristics of concrete. However, analytical approach in this scale has not been carried out enough yet. And in meso scale, mortar-aggregate interface is the weakest part in concrete so that it is considered that its material p...

The present paper offers a meso-scale numerical model to investigate the effects of random distribution of aggregate particles and steel fibers on the elastic modulus of Steel Fiber Reinforced Concrete (SFRC). Meso-scale model distinctively models coarse aggregate, cementitious mortar, and Interfacial Transition Zone (ITZ) between aggregate, mortar, and steel fibers with their respective materi...

Plans to modernize government processes and practices are leading to a reconsideraton of how to manage the vast range of knowledge resources that are found within the public sector. The theory and practice of Knowledge Management (KM) are found to be increasingly applied. This paper aims to explore the problems surrounding KM in one department of a large local authority in Scotland, namely the ...