Amol P. Bhondekar

Human opinion dynamics: An inspiration to solve complex optimization problems

Human interactions give rise to the formation of different kinds of opinions in a society. The study of formations and dynamics of opinions has been one of the most important areas in social physics. The opinion dynamics and associated social structure leads to decision making or so called opinion consensus. Opinion formation is a process of collective intelligence evolving from the integrative tendencies of social influence with the disintegrative effects of individualisation, and therefore could be exploited for developing search strategies. Here, we demonstrate that human opinion dynamics can be utilised to solve complex mathematical optimization problems. The results have been compared with a standard algorithm inspired from bird flocking behaviour and the comparison proves the efficacy of the proposed approach in general. Our investigation may open new avenues towards understanding the collective decision making.

Performance Evaluation of a Novel iTongue for Indian Black Tea Discrimination

In this work, the multi-electrode-single-frequency (MESF), multi-frequency-single-electrode (MFSE), and multi-frequency-multi-electrode (MFME) impedance responses of an impedance-Tongue reported previously, are evaluated for their discriminability of Indian Black Teas. Principal component analysis (PCA) in conjunction with a cluster validity measure, Davis-Bouldin Index (DBI), has been used for discriminability evaluation. The discriminabilities of electrode specific frequency segments chosen by optimization algorithms, namely, Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) have also been evaluated. The results show that the MFSE impedance response of Gold electrode gives the best discriminability without compromising the system complexity as against MESF, MFSE, MFME, and GA/PSO-optimized response. The results also suggest that the cross-sensitivity of electrodes may be enhanced by selecting optimum frequencies and/or electrodes, paralleling the practice of modifying the electrodes. This opens up a new approach towards qualitative and quantitative analysis of complex liquids.

Facile Route for the Synthesis of a Vertically Aligned ZnO–PANI Nanohybrid Film for Polyphenol Sensing

Vertically aligned zinc oxide (ZnO) nanorods have been fabricated on a polyaniline (PANI) film template after electrochemical seeding and hydrothermal growth in a nutrient medium at a low temperature of 65 °C. Dense c-oriented [0001], hexagonal-shaped, vertically aligned ZnO nanorods are obtained on the PANI film surface, which is confirmed by X-ray diffraction and scanning electron microscopy studies. The nanohybrid film used as the working electrode has been characterized for sensing catechin polyphenol in different tea varieties through cyclic voltammetry. Principal component analysis shows enhancement in the classification ability of the nanohybrid film for various concentrations of catechin standard and tea infusions.

Towards biological plausibility of electronic noses

The paper presents a novel encoding scheme for neuronal code generation for odour recognition using an electronic nose (EN). This scheme is based on channel encoding using multiple Gaussian receptive fields superimposed over the temporal EN responses. The encoded data is further applied to a spiking neural network (SNN) for pattern classification. Two forms of SNN, a back-propagation based SpikeProp and a dynamic evolving SNN are used to learn the encoded responses. The effects of information encoding on the performance of SNNs have been investigated. Statistical tests have been performed to determine the contribution of the SNN and the encoding scheme to overall odour discrimination. The approach has been implemented in odour classification of orthodox black tea (Kangra-Himachal Pradesh Region) thereby demonstrating a biomimetic approach for EN data analysis.

DEVELOPMENT AND OPTIMIZATION OF AN HPLC METHOD FOR THE ROUTINE ANALYSIS OF CATECHINS, CAFFEINE, AND GALLIC ACID IN TEA (CAMELLIA SINENSIS)

An efficient and rapid high performance liquid chromatographic (HPLC) assay was developed for the quantification of catechins [(+) – catechin, (−) – epigallocatechin, (−) – epigallocatechingallate, (−) – epicatechin, and (−) – epicatechingallate], caffeine, and gallic acid in tea (Camellia Sinesis var. sinesis). The assay was optimized by varying sample strength, column temperature, gradient type, and detection wavelength. A curved gradient using a Thermo Hypersil ODS column with 0.05% orthophosphoric acid and methanol as mobile phase A and B, respectively, and UV detection at 277.5 nm was employed. It was observed that a curved gradient along with an optimal temperature, dramatically improves the signal to noise ratio and separation profile. The limit of detection (LOD) and limit of quantification (LOQ) were found to be in the range of 1.04–22.81 µg mL−1 and 3.47–76.05 µg mL−1 respectively. The overall precision values obtained from the analysis of Kangra and Darjeeling orthodox tea samples were within the range of 0–0.34 (standard error).

A traffic aware cluster head selection mechanism for hierarchical wireless sensor networks routing

Energy efficient routing is an important aspect of Wireless Sensor Networks for prolonging the lifetime of battery powered energy constrained nodes. Heterogeneities in nodes energy, computation, and link have been considered in the area. However, the effect of traffic generation rate, which may be different for different nodes in heterogeneous WSN, is not well considered. In this paper, we have considered traffic heterogeneity, and analyzed its effect on well known hierarchical clustering based routing algorithm in the area. Also, we have proposed an improved cluster head selection mechanism under the traffic heterogeneous scenario. The approach can enhance the performance of existing commercial algorithms, and it could be an important aspect while developing new routing algorithms for heterogeneous WSN scenarios.

Understanding the Odour Spaces: A Step towards Solving Olfactory Stimulus-Percept Problem

Odours are highly complex, relying on hundreds of receptors, and people are known to disagree in their linguistic descriptions of smells. It is partly due to these facts that, it is very hard to map the domain of odour molecules or their structure to that of perceptual representations, a problem that has been referred to as the Structure-Odour-Relationship. We collected a number of diverse open domain databases of odour molecules having unorganised perceptual descriptors, and developed a graphical method to find the similarity between perceptual descriptors; which is intuitive and can be used to identify perceptual classes. We then separately projected the physico-chemical and perceptual features of these molecules in a non-linear dimension and clustered the similar molecules. We found a significant overlap between the spatial positioning of the clustered molecules in the physico-chemical and perceptual spaces. We also developed a statistical method of predicting the perceptual qualities of a novel molecule using its physico-chemical properties with high receiver operating characteristics(ROC).

DNA-based high-density memory devices and biomolecular electronics at CSIO

During the last half century the electronic components and computers have grown more and more powerful with the shrinking dimensions of transistors which is approaching 100nm with about a billion tiny devices working together on a single processor. The laws of quantum mechanics and limitations of materials and fabrication techniques restrict further reduction below 100nm. The most promising area is Biomolecular Electronics concerning design and fabrication of basic electronic components using biomolecules. Various organic polymers are being studied for visualization of individual molecular electronic wires and diode switches but we see enormous potential in use of DNA for such devices due to its inherent characteristics. This is because DNA can act as insulator semiconductor, conductor or superconductor depending upon the base sequence, length and orientation. The DNA can be coated selectively with metals with molecular level precision giving us capability to design molecular electronic components, such as, diode, triode, transistor, etc. This paper discusses the DNA based language developed by our group for coding and decoding any digital information in terms of DNA sequence. Basic arithmetical operations, such as, addition subtraction, multiplication, division and exponential have been defined in terms of DNA sequence and their validity has been demonstrated. Paper will also discuss our programme on study of DNA electrical behaviour in terms of sequence; length and orientation for development of biomolecular electronic components and for understanding DNA damaged chemistry.

A review on technological advancements in crowd management

With more and more people attending public gatherings, and with a continuous rise in crowd density in urban areas, the management of crowd has become more challenging than ever before. Every year, many people lose their lives due to inefficient crowd planning and management. Crowd management is an interdisciplinary area, and it requires understanding of engineering and technological aspects, along with an understanding of crowd behavior and crowd flow management, i.e. psychological and sociological aspects. This paper presents a broad, but not exhaustive overview of the recent technological advancements in the area of crowd planning and monitoring techniques for an effective crowd management system. It discusses the crowd modeling aspects during the planning of crowded scenario, and the technological advancements in crowd data acquisition techniques [based on Vision, Wireless/Radio-Frequency (RF) and Web/Social-media data mining technologies] during execution of crowded event. The paper also considers technological applications in some highly crowded scenarios on earth as case studies, along with future research directions in the area.

Bacteriorhodopsin–ZnO hybrid as a potential sensing element for low-temperature detection of ethanol vapour

Summary Zinc oxide (ZnO) and bacteriorhodopsin (bR) hybrid nanostructures were fabricated by immobilizing bR on ZnO thin films and ZnO nanorods. The morphological and spectroscopic analysis of the hybrid structures confirmed the ZnO thin film/nanorod growth and functional properties of bR. The photoactivity results of the bR protein further corroborated the sustainability of its charge transport property and biological activity. When exposed to ethanol vapour (reducing gas) at low temperature (70 °C), the fabricated sensing elements showed a significant increase in resistivity, as opposed to the conventional n-type behaviour of bare ZnO nanostructures. This work opens up avenues towards the fabrication of low temperature, photoactivated, nanomaterial–biomolecule hybrid gas sensors.