An efficient approach for face recognition based on common eigenvalues

In this paper, a simple technique is proposed for face recognition among many human faces. It is based on the polynomial coefficients, covariance matrix and algorithm on common eigenvalues. The main advantage of the proposed approach is that the identification of similarity between human faces is carried out without computing actual eigenvalues and eigenvectors. A symmetric matrix is calculated using the polynomial coefficients-based companion matrices of two compared images. The nullity of a calculated symmetric matrix is used as similarity measure for face recognition. The value of nullity is very small for dissimilar images and distinctly large for similar face images. The feasibility of the propose approach is demonstrated on three face databases, i.e., the ORL database, the Yale database B and the FERET database. Experimental results have shown the effectiveness of the proposed approach for feature extraction and classification of the face images having large variation in pose and illumination.     

Thermo gravimetric analysis and morphological behavior of castor oil based polyurethane–polyester nonwoven fabric composites

Castor oil (CO) based polyurethane (PU)– polyester nonwoven fabric composites were fabricated by impregnating the polyester nonwoven fabric in a reactive composition containing CO and diisocyanate. Composites were fabricated with two different isocyanates such as toluene‐2, 4‐diisocyanate (TDI) and hexamethylene diisocyanate (HMDI). Thermogravimetric analysis (TGA) studies of the composites were performed to establish the thermal stability and their mode of thermal degradation. It was found that degradation of neat PU takes place in two steps and that of polyester nonwoven fabric reinforced PU composites takes place in three steps. From the TGA thermograms, a little improvement in thermal stability incase of polyester nonwoven fabric reinforced PU composites were noticed compared to unreinforced PUs. Degradation kinetic parameters were obtained for the composites using Broido, Coats and Redfern, and Horowitz and Metzger methods. Tensile fractured composite specimens were used to analyze the morphology of the composites by scanning electron microscopic technique. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Video sequence feature extraction and segmentation using likelihood regression model

The development of digital technology is utilized by people to capture and share video frames. At present, rather than capturing images, people are interested in recording video footage for exploring information. Here, retrieval of video from large databases is challenging due to the continuous frame count. To overcome these challenges associated with the retrieval of video from available databases, this research proposed a likelihood-based regression approach for video processing. To improve the retrieval accuracy of video sequences, the proposed method utilizes a likelihood estimation technique integrated with a regression model. The likelihood estimate measures the pixel level roughly for estimating the pixel range, after which the regression approach measures the pixel level for transforming certainly blurred and unwanted pixels. In the proposed likelihood regression approach, the video is converted into a video frame and stored in a database. Query frames are taken into account by the generated database depending on the features which are used for a given video to be retrieved. The significant video retrieval performance obtained from the simulation results for the proposed likelihood-based regression model shows that the proposed model performs well over the other state-of-the-art techniques.

     

Preservation of strawberries by modified atmosphere packages with other treatments

The impact of modified atmosphere packaging (MAP), in combination with ozone treatment and an edible film coating, on the preservation of strawberries was studied. A combination of 2.5% O₂ with 15% CO₂ was the optimum gas composition for the MAP of strawberries and prolonged shelf‐life by 4–6 days. When the strawberries were pre‐treated with a 4.3 mg/m³ ozone water dip and an edible coating prior to packaging, the shelf‐life was extended to 8–10 days. The results showed that two treatments [No.1: polyvinyl alcohol 134 (2%); monostearatacylglycerol (0.5%); phytic acid (0.05%); sorbitol (0.05%); sodium alginate (0.1%); absolute alcohol (8%): No.2: polyvinyl alcohol 134(1%); soluble starch (1%); glucose (1%); sucrose (1%); sodium alginate (0.1%); sorbitol (0.05%)] gave the best effects on strawberry quality and shelf‐life. All treatments (Nos 1–4) were obviously superior to check experiments for soluble sugar, ascorbic acid, acidity and anthocyanin. Furthermore, the treatments gave superior results for browning index, commodity ratio and permeability of the cell membrane. Copyright © 2006 John Wiley & Sons, Ltd.     

Energy harvesting from far field RF signals

In this article, an alternative source of energy harvesting is proposed. It is based on the concept of charge pump electronics circuit and radio frequency (RF) signal amplifier. The RF signals are acquired by the Dickson charge pump circuit, amplified, and converted into a desired DC signal. To ensure the maximum power extraction, the proposed energy harvester circuit includes multiple circuit level approach. The diode‐capacitor charge pump generated the step‐up stage in the system. The proposed idea is designed and implemented using a suitable hardware successfully. Initially, the designed circuit is simulated and tested using the MultiSim software and then hardware implemented to obtained the desired 1‐5 V DC signal. The presented circuit can be used in various applications such as electronic devices charging, power supply, energy harvesting, etc.     

Elucidating the Effects of Cu‐Nanoparticles in a Porous Medium vis‐à‐vis Heat Transfer Phenomena

In this paper, a numerical simulation technique is developed to investigate the qualitative and quantitative behaviour of Cu‐nanoparticles in a porous medium vis‐a‐vis the heat transfer enhancements—buoyancy driven flow in a two‐dimensional square cavity, with moving walls is presented. The model utilizes the finite volume approach to solve the Brinkman–Darcy equations for Cu‐nanoparticles in a porous media. Discretization is carried out for convective and diffusive fluxes using Quadratic Upwind Interpolation for Convective Kinematics (QUICK) and central difference schemes, respectively. Tri‐Diagonal Matrix Algorithm is invoked to solve the set of algebraic equations. The Darcy number (Da), Prandtl number (Pr), and volume fraction (χ) are varied from 10^?3 to 10^?1, 3 to 7, and 0% to 20%, respectively. Insight into the cause of variations in isotherms, streamlines, Nusselt number (Nu), and mid‐plane velocities is explicated. The present numerical results are compared with the existing literature and found to be in good agreement. Even though nanoparticles slightly hinder the activity of the fluid, they can augment the average Nu by 90% for Pr = 7, Da = 0.1, and χ = 20% as compared to the absence of nanoparticles. Their efficacy is more prominent for flows with higher Da and Pr. Quantitative values for Nu were obtained for various combinations of Pr, Da, and χ.     

Tailoring new bisphenol a ethoxylated shape memory polyurethanes

Shape memory polyurethanes (SMPUs) have generated great attention because of their unique properties. These properties are result of a particular molecular structure consisting of flexible molecular chains with low glass transition temperatures alternating with hard urethane segments. In this field, bisphenol A (BA) has been used for a long time as chain extender due to the good properties of the obtained SPMU materials. Nevertheless, the high toxicity of this compound has caused a high decrease on its use. For this reason, it has been selected a lower toxicity compound, bisphenol A ethoxylate (BAE). In this work, it is described a new SMPUs based on BAE and the influence of the hard segment on the thermo-mechanical properties and shape memory capacity. For that, both the proportion of the components and the diisocyanate employed (2,4-toluene diisocyanate (TDI), 4,4′-methylene bis(phenylisocyanate) (MDI) or a TDI/MDI mixture) have been modified. Then, depending on the molecular architecture achieved, the polyurethanes present different properties, which were studied by different techniques, such as thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic-mechanical thermal analysis (DMTA). It has been observed that glass transition temperature (T_g) increases as the hard phase content in the PU samples increases. In addition, T_g-MDI > T_g-MDI-TDI > T_g-TDI, so it is possible to control the T_g of the material, that is, shape memory transition temperature varying the diisocyanate. Finally, the shape memory capacity of the PUs was evaluated by thermo-mechanical analysis (TMA). All the synthesized PUs have shown good shape memory effect with fixation ratios up to 80% and recovery ratios close to 100%.     

Synthesis of monodispersed prolate spheroid shaped paramagnetic carbon

We demonstrate a single step, efficient, catalyst-and-solvent-free and scalable process for the synthesis of monodisperse, prolate spheroid shaped carbon (PSC) with 3 μm polar and 1.5 μm equatorial diameters by thermolysis of refined corn oil in a closed SS reactor at 700 °C. The autogenic pressure and in situ mass spectra during the thermolysis of corn oil were measured to gain insight on the reaction products as a function of temperature. We have characterized the morphology, structure, composition and magnetic property of PSC by using SEM, EDX, XRD, pair distribution function (PDF), solid state ¹³C NMR, Raman spectroscopy and EPR. We propose a putative mechanism for their formation by using all the complementary data.