Delhi Technological University

About: Delhi Technological University is a education organization based out in New Delhi, India. It is known for research contribution in the topics: Computer science & Control theory. The organization has 4427 authors who have published 6761 publications receiving 71035 citations. The organization is also known as: Delhi College of Engineering & DTU.

Adaptive Weighted Graph Approach to Generate Multimodal Cancelable Biometric Templates

Abstract: Multimodal biometric systems offer numerous advantages over unimodal counterparts and are being used extensively in diverse applications. However, fusion of biometric data is a non-trivial task and curtail employability of multimodal systems for a varying set of biometric characteristics with different type and dimension. Moreover, comprehensive solutions against adversary attacks that ensure template protection and prevent presentation attacks are not in place. In this article, a secure multimodal cancelable biometric system is proposed to address these concerns. This approach introduces key images based generic feature extraction technique which reduces feature dimension and achieves revocability. The non-invertibility and unlinkability are ensured through cross-diffusion of complementary information from different modalities. A new feature fusion method based on an adaptive graph is proposed to generate multimodal cancelable biometric templates. Robustness against presentation attack is accomplished through quality based adaptation of features. Extensive experimentation is performed on benchmark databases for fingerprint, face, and iris, to illustrate the efficacy of multimodal cancelable templates. The proposed approach is shown to perform favorably against state-of-the-art feature fusion methods. Furthermore, the resilience of the proposed approach against security and privacy attacks is demonstrated.

Fungus and plant-mediated synthesis of metallic nanoparticles and their application in degradation of dyes

Abstract: Nanomaterials have varied applications in a number of industries and hence have gained a lot of importance. While commercial production of nanoparticles has been successfully performed using traditional chemical methods, but they possess various environmental problems, due to which an alternative method is required. Green synthesis has proven to be advantageous due to its reliability, ecofriendliness, cost-effectiveness, and sustainability. One of the potential applications of nanoparticles is their role in the removal of toxic pollutants such as industrial dyes, heavy metals, and degradation of toxic chemicals. Among these pollutants, dyes are the organic substances which possess serious health hazards. A large number of nanoparticles are successfully used as catalysts for removal of dyes by various mechanisms including photodegradation, adsorption, and ion exchange. Therefore, in this chapter, we have discussed mycogenic and plant-mediated synthesis of nanoparticles and their potential role in degradation of dyes. Furthermore, prospects and challenges associated with the biogenic synthesis of nanoparticles have also been discussed.

Impedance spectroscopy analysis of Ba5NdTi3Nb7O30 ferroelectric ceramic

Abstract: The polycrystalline sample of Ba5NdTi3Nb7O30, a member of tungsten bronze family, was prepared by solid-state reaction method. X-ray diffraction (XRD) analysis shows the formation of single-phase compound with an orthorhombic structure. Scanning electron micrograph of the material shows uniform grain distribution throughout the sample. Variation of dielectric constant (e′r) with temperature at different frequencies shows that the compound has a dielectric anomaly of ferroelectric to paraelectric type at 100 °C, and exhibits non-relaxor kind of diffuse phase transition. Studies of electrical properties of Ba5NdTi3Nb7O30 using the complex impedance spectroscopy (CIS) technique show the decrease in bulk resistance with rise in temperature indicating a typical negative temperature coefficient of resistance (NTCR)-type behaviour. A possible hopping mechanism for electrical transport in the system is evident from the modulus analysis.