Arguing the Value of Product Quality Signaling in the Presence of Negative Publicity

Drawing on argumentation and signaling theories, this study designs an escalating warrant model and examines the manner in which it connects to the influence of negative publicity. A parsimonious framework is developed for forming the multiple product warranties and assessment of the separate and simultaneous effects. The experiment shows that consumers do reason with sellers’ product quality information, while they are easier to convince and infer a higher level of seller credibility when there are more types of warrant. However, this positivity can be reversed and cause significantly greater damage to the seller’s standing in the face of negative publicity

Nearly uniform sampling of crystal orientations

International audienceA method is presented for generating nearly uniform distributions of three-dimensional orientations in the presence of symmetry. The method is based on the Thomson problem, which consists in finding the configuration of minimal energy of N electrons located on a unit sphere – a configuration of high spatial uniformity. Orientations are represented as unit quaternions, which lie on a unit hypersphere in four-dimensional space. Expressions of the electrostatic potential energy and Coulomb's forces are derived by working in the tangent space of orientation space. Using the forces, orientations are evolved in a conventional gradient-descent optimization until equilibrium. The method is highly versatile as it can generate uniform distributions for any number of orientations and any symmetry, and even allows one to prescribe some orientations. For large numbers of orientations, the forces can be computed using only the close neighbourhoods of orientations. Even uniform distributions of as many as 10 6 orientations, such as those required for dictionary-based indexing of diffraction patterns, can be generated in reasonable computation times. The presented algorithms are implemented and distributed in the free (open-source) software package Neper

Large-scale 3D random polycrystals for the finite element method: Generation, meshing and remeshing

International audienceA methodology is presented for the generation and meshing of large-scale three-dimensional random polycrystals. Voronoi tessellations are used and are shown to include morphological properties that make them particularly challenging to mesh with high element quality. Original approaches are presented to solve these problems: (i) "geometry regularization", which consists in removing the geometrical details of the polycrystal morphology, (ii) "multimeshing" which consists in using simultaneously several meshing algorithms to optimize mesh quality, and (iii) remeshing, by which a new mesh is constructed over a deformed mesh and the state variables are transported, for large strain applications. Detailed statistical analyses are conducted on the polycrystal morphology and mesh quality. The results are mainly illustrated by the high-quality meshing of polycrystals with large number of grains (up to 105), and the finite element method simulation of a plane strain compression of ε = 1.4 of a 3000-grain polycrystal. The presented algorithms are implemented and distributed in a free (open-source) software package: Neper

Exploring the Marketing Effect of Corporate Social Responsibility -An Experimental Design Approach

Abstract Corporate social responsibility (CSR) is value oriented, based on the perspectives of stakeholders and issues considered essential. Using experimental design, this study designs scenarios in terms of consumer's prior purchase experience with products associated to CSRs. The purpose aims to demonstrate the marketing effect of CSR initiative whereby it stimulates buyers to purchase a high priced CSR-related product or stay with such a product when they are aware of the CSR behavior of the seller. Such effect is examined further for those of less or no prior experience in purchasing CSR-related goods. Our goal is to explore the response of general consumers on ethics relevant issues for better understanding of CSR in business

Simulation of uniaxial tensile behavior of quasi-brittle materials using softening contact models in DEM

This study proposes new contact models to be incorporated into discrete element method (DEM) to more accurately simulate the tensile softening in quasi-brittle materials, such as plain concrete and masonry with emphasis on fracture mechanism and post-peak response. For this purpose, a plain concrete specimen (double notched) and stack bonded masonry prism under direct tensile test are modeled. Furthermore, mixed mode crack propagation is investigated in concrete and brickwork assemblages. Two modeling approaches are proposed, the simplified and detailed meso modeling, both based on DEM. In the simplified meso-model, a smooth contact surface is considered between two separate blocks, whereas the internal structure of the material is explicitly represented as a tessellation into random polyhedral blocks in the detailed meso-model. Furthermore, recently developed tensile softening contact constitutive models implemented into a commercial discrete element code (3DEC) are used to simulate the softening behavior of concrete and masonry. As an important novel contribution, it is indicated that the proposed computational models successfully capture the complete (pre- and post-peak) material behavior and realistically replicate the cracking mechanism. Additionally, a sensitivity analysis demonstrates the influence of the various micro-contact parameters on the overall response of the examined materials.Authors would like to express their gratitude to Itasca Educational Partnership Program (IEP) for their kind support and providing 3DEC softwar

Influence of carbide distribution on ductility of Haynes®282® forgings

Haynes®282®, a relatively new superalloy is used in gas turbines in form of sheets, plates and forgings. Forgings undergo a series of deformation steps at high temperatures to form complex shapes of components. The deformation on forgings, changes the microstructural features and their distribution, and any change in distribution of microstructural features can affect the mechanical properties of the material. The present study is undertaken to investigate the possible causes of anisotropy in mechanical properties of a Haynes®282® forging through optical and electron microscopy. Microscopic investigations show that ductility is anisotropic and changes from 15% to 21%. The electron backscattered diffraction (EBSD) investigation reveals that the presence of carbide stringers (banding of MC and M6C carbides) is associated with fine grains, thereby giving a bimodal distribution of grain size. Carbide stringers follow the complexity of forgings and are identified as the primary cause for the anisotropic behavior in ductility. Furthermore, micromechanical simulations of carbide stringers in association with a bimodal grain structure was seen to qualitatively correspond to the experimental observation indicating improved ductility with banding along the tensile axis

Innovative Material Technology: Chaotic Motion of Single-Walled Carbon Nanotube with Linear and Nonlinear Damping

In the present study, the effects on chaotic behaviors of single-walled carbon nanotube (SWCNT) due to the linear and nonlinear damping are investigated. By using the Hamilton's principle, the nonlinear governing equation of the single-walled carbon nanotube embedded in a matrix is derived. The Galerkin's method is adopted to simplify the integro-partial differential equation into a nonlinear dimensionless governing equation for the SWCNT, which turns out to be a forced Duffing equation. The variations of the Lyapunov exponents of the SWCNT with damping and harmonic forcing amplitudes are investigated. Based on the computations of the top Lyapunov exponent, it is concluded that the chaotic motion of the SWCNT occurs when the amplitude of the periodic excitation exceeds certain value, besides, the chaotic motion of the SWCNT occurs with small linear damping and tiny nonlinear damping

Ray Tracing Simulation in Nonspherically Symmetric Atmosphere for GPS Radio Occultation

A three-dimensional ray tracing model with aiming algorithms for global positioning system (GPS) signal is proposed to make simulations conform to the realistic radio occultation (RO) signal propagation. The two aiming algorithms used in this study ensure the initial and end point ray trajectories are located in the prescribed region. In past studies, the ray tracing techniques applied to the RO signal simulation usually assumed a spherically symmetrical atmosphere for simplicity. The exact GPS and low earth orbit (LEO) satellite locations are not considered in the simulation. These two assumptions make the simulation unrealistic for GPS signal propagation in the RO technique. In the proposed model, the shape of the earth is assumed as an ellipse. The information from European Centre for Medium-Range Weather Forecasts (ECMWF) analysis is used to setup the atmosphere in the simulation. Two aiming algorithms are developed to determine the initial signal propagating direction to make the simulated signal start from the prescribed GPS satellite position and end in the close vicinity of the LEO satellite position. An ideal spherical symmetric atmospheric structure is used to verify the ray tracing model. The fractional difference between real and simulated refractivity results is less than 0.1%. Otherwise, the GPS and LEO satellite position in the Formosat-3/COSMIC observation and the ECMWF analysis, considering the earth¡¦s flattening, is also used to verify the aiming algorithms. All of the simulated signals end in close vicinity to the LEO satellite position in the simulation results