Uniaxial tensile response of microfibre reinforced cement composites

Microfibre reinforced cement composites reinforced with high volume fractions of carbon, steel and polypropylene fibres were tested in uniaxial tension. Composites investigated included those with only one type of fibre (mono-fibre composites) and those with two or more types of fibres (hybrid-fibre composites) in the same mix. Considerable strengthening, toughening and stiffening of the host matrix due to microfibre reinforcement were observed. In the hybrid-fibre composites, different fibres appear to act as additive phases; i.e., they maintain their individual reinforcing capabilities. The composites were also impact tested in uniaxial tension using a newly designed instrumented impact machine. When compared with static test results, considerable sensitivity to stress rate was noted; composites were found to be stronger and tougher under impact and the improvements were more pronounced at higher fibre volume fractions. The potential of these composites for use in thin sheet products and other similar applications is recognized, and the need for continued research is stressed.     

Analysis of e-business models in real estate

We use Canvas Application Framework to analyze e-business models of Realestate.yahoo.com, Yahoo.com, Redfin.com, Realtor.com, Trulia.com, Zillow.com, and Craigslist.com. We investigate the similarities and differences among e-business models and how e-business model differentiation affects company success. We looked at which business model components, such as distribution channels, business partnerships, attracting customers, revenue streams, etc., are important. We further investigate whether the web-advertising, brokerage, virtual value-chain, or the diversified internet business model is used by each company, and which ones are more successful. We discover similarities and differences among e-business models. Differences include the use of revenue streams for generating revenue, the extent of partnerships, and the role they play in a company’s success.     

Polyvinylidene fluoride nanofibers obtained by electrospinning and blowspinning: Electrospinning enhances the piezoelectric β-phase – myth or reality?

Considerable effort has been devoted to improving the properties of PVDF (polyvinylidene fluoride), arguably the most technologically important piezoelectric polymer. Electrospinning has been found to be a particularly effective method of producing PVDF nanofibers with superior piezoelectric properties due to the resulting exceptionally high fraction of the piezoelectrically active crystalline β-phase. It is typically assumed that the high external electric fields applied during electrospinning enhance the formation of this β-phase, with the confused literature offering various unsatisfactory mechanistic explanations. However, by comparing PVDF nanofibers produced by two different processes (electrospinning and blowspinning), we show that the electric field is entirely unnecessary; indeed, the crystallization dynamics are principally driven by the applied mechanical stress, as evidenced by structurally identical 200 nm diameter PVDF fibers produced with and without external electric fields.     

A dynamic video watermarking algorithm in fast motion areas in the wavelet domain

In this paper, we propose a video watermarking algorithm which embeds different parts of a single watermark into different shots of a video under the wavelet domain. Based on a Motion Activity Analysis, different regions of the original video are separated into perceptually distinct categories according to motion information and region complexity. Thus, the localizations of the watermark are adjusted adaptively in accordance with the human visual system and signal characteristics, which makes them perceptually invisible and less vulnerable to automated removal. In addition, contrary to traditional methods where the watermark remains at a fixed position on the screen, the watermark moves along with moving objects and thus motion artefacts can be avoid. The multi-frame based extraction strategy ensures that the watermark can be correctly recovered from a very short segment of video. Individual frames extracted from the video also contain watermark information. Experimental results show that the inserted watermark is not only less perceptible but also robust against common video processing attacks.     

Improved Interface Conditions for 2<Emphasis Type="Italic">D</Emphasis> Domain Decomposition with Corners: Numerical Applications

This article deals with a local improvement of domain decomposition methods for 2-dimensional elliptic problems for which either the geometry or the domain decomposition presents conical singularities. After explaining the main results of the theoretical analysis carried out in Chniti et al. (Calcolo 45, 2008), the numerical experiments presented in this article confirm the optimality properties of the new interface conditions.     

Prediction of visual attention with deep CNN on artificially degraded videos for studies of attention of patients with Dementia

Multimedia Tools and Applications - Studies of visual attention of patients with Dementia such as Parkinson’s Disease Dementia and Alzheimer Disease is a promising way for non-invasive...     

Simulation-based investigations on the drape behavior of 3D woven fabrics made of commingled yarns

Composites based on 3D woven fabrics offer excellent mechanical properties due to the nearly non-crimp reinforcement fibers. Additionally, a reduced number of process steps results from the 3D nature of the reinforcement. Their in-plane and out-of-plane behaviors are purposefully adjustable to the expected loading conditions. A previously introduced modelling approach is extended to the simulation of 3D woven fabrics. The tensile, shear and bending behaviors of the fabric are considered in a material formulation for large deformations using shell elements. The model is successfully validated and parameter studies show the significant influence of shear and bending parameters on forming results. Furthermore, it is shown that also the forming process parameters have a significant influence on the draping results. It is concluded that the shearing and wrinkling can be reduced to a minimum with adapted material and process parameters.     

Rapid and efficient hand gestures recognizer based on classes discriminator wavelet networks

Multimedia Tools and Applications - The vision based on hand gesture recognition is one of the key challenges in behavior understanding and computer vision. It offers to machines the possibility of...