The stable and precise motion control for multiple mobile robots

Intelligent path planning of multiple mobile robots has been addressed in this paper. Cooperative behaviour can be achieved using several mobile robots, which require online inter-communication among themselves. In the present investigation rule-based and rule-based-neuro-fuzzy techniques are analyzed for multiple mobile robots navigation in an unknown or partially known environment. The final aims of the robots are to reach some pre-defined goals. Based upon a reference motion, direction; distances between the robots and obstacles; distances between the robots and targets; different types of rules are taken heuristically and refined later to find the steering angle. The control system combines a repelling influence related to the distance between robots and nearby obstacles and with an attracting influence between the robots and targets. Then a hybrid rule-based-neuro-fuzzy technique is analyzed to find the steering angle of the robots. Results show that the proposed rule-based-neuro-fuzzy technique can improve navigation performance in complex and unknown environments compared to this simple rule-based technique.     

Experimental demonstration of non-local controlled-unitary quantum gates using a five-qubit quantum computer

Local implementation of non-local quantum gates is necessary in a distributed quantum computer. Here, we demonstrate the non-local implementation of controlled-unitary quantum gates proposed by Eisert et al. (Phys Rev A 62:052317, 2000) using the five-qubit IBM quantum computer. We verify the fidelity and accuracy of the implementation through the techniques of quantum state and process tomographies.     

DC Electrical Resistivity Study of Granularity in YBa2CU3O7/Ag Composites

Temperature-dependent electrical resistivity in a set of YBa₂Cu₃O_7–x /Ag composites, all prepared under an identical sintering schedule, is analyzed to extract granularity information. The weak-link resistivity _wl across the grain boundaries and the percolation factor arising due to current frustration caused by misalignment of anisotropic grains and sample defects such as voids and cracks are estimated from the residual resistivity ₀ and the temperature coefficient of resistivity d/dT. Variation of these parameters with Ag vol.% quantifying the extent of granularity indicates that granularity in the composites decreases and their electrical characteristics tend to be identical to that of Ag-free YBa₂Cu₃O_7–x single crystals and epitaxial thin films as Ag vol.% approaches a value where onset of current percolation occurs through Ag channels. The increased and decreased _wl observed at higher Ag vol.% explains the larger grains in the composites with narrow size distribution.     

Emotion recognition from geometric facial features using self-organizing map

This paper presents a novel emotion recognition model using the system identification approach. A comprehensive data driven model using an extended Kohonen self-organizing map (KSOM) has been developed whose input is a 26 dimensional facial geometric feature vector comprising eye, lip and eyebrow feature points. The analytical face model using this 26 dimensional geometric feature vector has been effectively used to describe the facial changes due to different expressions. This paper thus includes an automated generation scheme of this geometric facial feature vector. The proposed non-heuristic model has been developed using training data from MMI facial expression database. The emotion recognition accuracy of the proposed scheme has been compared with radial basis function network, multi-layered perceptron model and support vector machine based recognition schemes. The experimental results show that the proposed model is very efficient in recognizing six basic emotions while ensuring significant increase in average classification accuracy over radial basis function and multi-layered perceptron. It also shows that the average recognition rate of the proposed method is comparatively better than multi-class support vector machine.     

Comparative analysis of desizability and retrogradation behavior of various sizing materials

The advent of high-speed shuttleless looms has increased the importance of sizing. Starch has been the most popular and economic size material. Synthetic binders are also being blended with starch to improve weaving loom efficiency. Some synthetic size materials have restrictions in use mainly because of ecological reasons. In the recent years, many modifications have come up in the starch as a sizing agent. Different modifications can give different properties, which can suit to particular application. In this study, different varieties of natural starch, modified starch, and synthetic size materials are evaluated, and properties like retrogradation and desizability were studied to investigate their potential for modern weaving conditions. Comparison is made between various materials and it is observed that paste characteristics and film properties of certain modified starches are better than the natural starch. The experiment was also designed to check the properties of blend constitution. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Optimization and modelling of volatile fatty acid generation in a leachate bed reactor for utilization in microbial fuel cells

Volatile fatty acid (VFA)-rich leachate generated from acidogenesis of kitchen waste in a leach bed reactor (LBR) was utilized in an earthen microbial fuel cell (EMFC) to generate electricity. Effects of organic loading rate (OLR, 5–10 g VS/L·day) and pH (5–7) on LBR enumerated optimized parameters of OLR (10 g VS/L·day) and pH (5.74) to obtain total VFA (TVFA) of 7.7 ± 0.3 g/L in the leachate, with maximum contribution from acetic acid. Leachate obtained from the LBR was fed to the EMFC with varying OLR (2–7 kg COD/m³·day). The highest power density of 0.76 W/m³ (at OLR 7 kg COD/m³·day) was obtained with higher VFA content in the leachate. A neural network based on the Levenberg–Marquard function effectively predicted chemical oxygen demand and TVFA removal. This study establishes LBR as a techno-economic method to obtain useful substrate for EMFC. Furthermore, the response modelling of EMFC demonstrates the potential of utilizing machine learning in biological treatment.     

Acylperoxycoumarins as ortho‐C?H Acylating Agent via a Palladium(II)‐Catalyzed Redox‐Neutral Process

An unprecedented palladium(II)‐catalyzed biomimetic aliphatic acyl (‐COR) group transfer was observed from acyl‐α‐peroxycoumarins to the ortho C H sites of directing arenes. Here, the C H activation is associated with a concomitant acyl group transfer via a Pd(II)‐catalyzed, redox‐neutral process. While methods for ortho aroylation (‐COAr) are well documented ortho acylation (‐COR) processes are scarce, hence the present redox‐neutral method is most ideal for o‐acylation of directing substrates.

     

Swift heavy ion irradiation induced texturing in NiO thin films

NiO thin films grown on Si(1 0 0) substrate by electron beam evaporation and sintered at 500 and 700 °C were irradiated with 120 MeV Au⁹⁺ ions. The FCC structure of the sintered films was retained up to the highest fluence (3 × 10¹³ ions cm⁻²) of irradiation. In the low fluence (?1 × 10¹³ ions cm⁻²) regime however, the evolution of the XRD pattern with fluence showed a wide variation, critically depending upon their initial microstructure. Though irradiation is known to induce disorder in the structure, we observe improvement in crystallization and texturing at intermediate fluences of irradiation.     

Comparative study of bio-ethanol production from mahula (Madhuca latifolia L.) flowers by Saccharomyces cerevisiae and Zymomonas mobilis

Mahula (Madhuca latifolia L.) flower is a suitable alternative cheaper carbohydrate source for production of bio-ethanol. Recent production of bio-ethanol by microbial fermentation as an alternative energy source has renewed research interest because of the increase in the fuel price. Saccharomyces cerevisiae (yeast) and Zymomonas mobilis (bacteria) are two most widely used microorganisms for ethanol production. In this study, experiments were carried out to compare the potential of the yeast S. cerevisiae (CTCRI strain) with the bacterium Z. mobilis (MTCC 92) for ethanol fermentation from mahula flowers. The ethanol production after 96 h fermentation was 149 and 122.9 g kg⁻¹ flowers using free cells of S. cerevisiae and Z. mobilis, respectively. The S. cerevisiae strain showed 21.2% more final ethanol production in comparison to Z. mobilis. Ethanol yield (Yx/s), volumetric product productivity (Qp), sugar to ethanol conversion rate (%) and microbial biomass concentration (X) obtained by S. cerevisiae were found to be 5.2%, 21.1%, 5.27% and 134% higher than Z. mobilis, respectively after 96 h of fermentation.