Visual–Motor Coordination Using a Quantum Clustering Based Neural Control Scheme

Visual–Motor Coordination is a problem considered analogous to the hand-eye coordination in biological systems. In this work we propose a novel approach to this problem using Quantum Clustering and an extended Kohonen's Self-Organizing Feature Map (K-SOFM). This facilities the use of the method in varying workspaces by considering the joint angles of the robot arm. Unlike previous work, where a fixed topology for the input space is considered, the proposed approach determines a topology as the workspace varies. Quantum Clustering is a method which constructs a scale-space probability function and uses the Schroedinger equation and its lowest eigenstate to obtain a potential whose minimum gives the cluster centers. It transforms the input space into a Hilbert space, where it searches for its minimum. The motivation of this work is to identify the implicit relationship existing between the end-effector positions and the joint angles through Quantum Clustering and Neural Network methods to fine-tune the system to correctly identify the mapping.     

Cadmium(II)‐Catalyzed C?N Cross‐Coupling of Amines with Aryl Iodides

Cadmium diacetate dihydrate [Cd(OAc)₂⋅2 H₂O] in combination with ethylene glycol catalyzes efficiently the C N cross‐coupling of amines with aryl iodides by a benzyne mechanism. Alkyl, aryl and heterocyclic amines are compatible with this system affording the aminated products in high to excellent yield.     

Experimental verification of pH localization mechanism of particle consolidation at the electrode/solution interface and its application to pulsed DC electrophoretic deposition (EPD)

Experimental measurement and verification of the pH localization at the electrode/solution interface was conducted during continuous and pulsed DC electrophoretic deposition (EPD) from aqueous solution. Application of pulsed DC enabled controlling bubble incorporation and obtaining bubble-free deposits during electrophoretic deposition (EPD) from aqueous suspension. The pH localization at the electrode/solution interface on application of electric field was attributed as the underlying mechanism of particle consolidation during continuous as well as pulsed EPD. The suspension pH tends to shift towards isoelectric point (i.e.p.) leading to spontaneous coagulation of particles at the electrode. Application of continuous DC tends to attain the i.e.p. faster and closer compared to pulse DC leading to maximum deposit yield. The kinetics and closeness of attainment of pH towards i.e.p. decreased progressively with decreasing pulse size resulting in a corresponding decrease in deposit yield.     

Electrophoretic deposition of doped ceria in anti-gravity set-up

An innovative anti-gravity set-up has been designed and fabricated to consolidate doped ceria powder by electrophoretic deposition. In this set-up, the charged ceramic powders dispersed in non-aqueous suspension moved upward in opposite direction to gravity under the influence of an external applied field and were consequently deposited on the lower face of upper electrode placed horizontally parallel above the counter electrode. Electrophoretic deposition using this innovative technique was found more superior to the conventional electrophoretic deposition using vertically arranged electrodes where a very broad particle size range was used. The deposit thus obtained predominantly contained finer particles which can move relatively easily against gravity. It enabled formation of homogeneous compact films. This paper presents the results of detailed investigation on the effect of different process parameters such as concentration of particles, duration, addition of charge modifier etc. on forming a deposit. A comparison of deposition yield in anti-gravity set-up vis-à-vis conventional set-up is also presented.     

Electrophoretic deposition of alumina on stainless steel from non-aqueous suspension

Electrophoretic deposition of alumina on stainless steel has been investigated. The influence of different organic media and deposition parameters such as solid concentration, applied voltage and time of deposition on deposit yield has been evaluated. Maximum deposit yield was obtained for solvent media that imparts highest magnitude of surface charge on alumina in suspension. The deposit yield increased linearly with concentration of alumina powder in suspension, and applied voltage following Hamakers law. A similar linearity in yield was observed at short deposition times, but a deviation in linearity was observed at higher time of deposition, which is attributed to the shielding effect of the deposited layers and accumulation of ions at the electrode, and depletion of powder in the suspension with progress in deposition.     

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.     

Variable-gain controllers for nonlinear systems using the T-S fuzzy model.

This correspondence proposes two novel control schemes with variable state-feedback gain to stabilize a Takagi-Sugeno (T-S) fuzzy system. The T-S fuzzy model is expressed as a linear plant with nonlinear disturbance terms in both schemes. In controller I, the T-S fuzzy model is expressed as a linear plant around a nominal plant arbitrarily selected from the set of linear subsystems that the T-S fuzzy model consists of. The variable gain then becomes a function of a gain parameter that is computed to neutralize the effect of disturbance term, which is, in essence, the deviation of the actual system dynamics from the nominal plant as the system traverses a specific trajectory. This controller is shown to stabilize the T-S fuzzy model. In controller II, individual linear subsystems are locally stabilized. Fuzzy blending of individual control actions is shown to make the T-S fuzzy system Lyapunov stable. Although applicability of both control schemes depends on the norm bound of unmatched state disturbance, this constraint is relaxed further in controller II. The efficacy of controllers I and II has been tested on two nonlinear systems.     

Electrophoretic deposition of doped ceria: Effect of solvents on deposition microstructure

Electrophoretic deposition of doped ceria has been carried out in non-aqueous solvent to prepare coatings on different substrates and free standing films. It has been found that uneven deposition occurred in ethanol, while in butanol deposition yield is low having very little variation with deposition time. On the other hand, good deposit obtained in acetyl acetone medium, but had a porous structure. The best result however was obtained in mixed solvent. Effect of adding charge modifying additives in the ceria suspension on the deposit microstructure has been studied. Mechanism of charging in the non-aqueous medium to modify the surface properties of the suspended particles has been discussed.