Vignan University

About: Vignan University is a education organization based out in Guntur, Andhra Pradesh, India. It is known for research contribution in the topics: Control theory & CMOS. The organization has 1138 authors who have published 1381 publications receiving 7798 citations.

Spatio-temporal estimation of rainfall patterns in north and northwestern states of India between 1901 and 2015: change point detections and trend assessments

Abstract: Change point detection and trend analysis are the adopted techniques of time series analysis. We have applied non-parametric methods on the temporal and spatial-scale data of 115 years between 1901 and 2015 from ten different federal states in the north and the northwestern India to examine the change points as well as to estimate the future scenarios by examining the past trends. The change points were examined by Pettitt’s test, Standard Normal Homogeneity (SNH) test, and Buishand’s test, whereas the trend analyses of monthly, annual, and seasonal rainfall data were carried out using Sen’s slope estimator after assessing their statistical significance by Mann–Kendall (M-K) test. The trend analyses showed non-zero slope values and a few among them were of statistical significance. The results of our statistical experiment concluded that the trends of reduction in winter, pre-monsoon, and post-monsoon rainfalls would have notable effects on the rain-fed agricultural production in the near future, particularly in the areas without proper irrigation facility (e.g., parts of Uttar Pradesh). More extreme events of higher rainfall in some states (e.g., Goa, Maharashtra, and Jammu and Kashmir), however might cause disasters like landslide and flooding.

An efficient multimodal person authentication system using Gabor and sub band coding

Abstract: This paper presents fusion of two biometric traits, i.e., face and speech, at matching score level fusion. The features are extracted from the pre-processed images of face and speech. Gabor Wavelet and Discrete Cosine Transform (DCT) are used to extract facial features and Sub Band Coding (SBC) is used to extract features from speech signals. These features of a probe image are compared with training images of each trait and then calculate matching score. The individual scores generated after each matching are passed to the fusion module. The final score is then used to declare the person as genuine or an impostor. The proposed method is tested on ORL database and it outperforms with False Acceptance Rate of 0.75% and False Rejection Rate of 1.24%.

Influence of carbon nanotubes/ graphene nanoparticles on the mechanical and morphological properties of glass woven fabric epoxy composites

Abstract: An epoxy matrix reinforced with multi-walled carbon nanotubes (MWCNTs) and graphene nano particles (GNPs) is used to fabricate woven glass fabric epoxy composites using Hand Layup and compression moulding technique. Three types of composites are fabricated using 7-mill plain weave glass fabric, +45o/-45o, 0o-90o multi axial glass woven fabrics as reinforcements and epoxy as matrix. Mechanical characterization is performed on the fabricated composites.0o-90o GWFE composites are fabricated with 0.5 wt%, 1.5 wt% MWCNTs, and 0.5 wt%, 1.5 wt% graphene nano particles (GNPs).The results from mechanical and morphological characterization revealed that specimens containing 0.5 wt%, 1.5 wt% MWCNTs, and 0.5wt %, 1.5 wt% graphene nanoparticles (GNPs) are altered when compared to the glass woven fabric epoxy composites without nanoparticles. Glass woven fabric epoxy (GWFE) composites with 1.5 wt% of MWCNT possess the highest hardness of 90.33 which is 6.27% greater when compared to other composites. The tensile strength of composite specimens containing 1.5 wt% graphene nanoparticles (GNPs) increased by 14.5% over glass woven fabric epoxy (GWFE) composites. The mode of fiber failure in tensile fractured surfaces of GWFE composites is apprised through SEM images.