National Institute of Technology, Karnataka

About: National Institute of Technology, Karnataka is a education organization based out in Mangalore, Karnataka, India. It is known for research contribution in the topics: Computer science & Corrosion. The organization has 5017 authors who have published 7057 publications receiving 70367 citations.

Automatic identification of diabetic maculopathy stages using fundus images.

Abstract: Diabetes mellitus is a major cause of visual impairment and blindness. Twenty years after the onset of diabetes, almost all patients with type 1 diabetes and over 60% of patients with type 2 diabetes will have some degree of retinopathy. Prolonged diabetes retinopathy leads to maculopathy, which impairs the normal vision depending on the severity of damage of the macula. This paper presents a computer-based intelligent system for the identification of clinically significant maculopathy, non-clinically significant maculopathy and normal fundus eye images. Features are extracted from these raw fundus images which are then fed to the classifier. Our protocol uses feed-forward architecture in an artificial neural network classifier for classification of different stages. Three different kinds of eye disease conditions were tested in 350 subjects. We demonstrated a sensitivity of more than 95% for these classifiers with a specificity of 100%, and results are very promising. Our systems are ready to run clinically on large amounts of datasets.

Trend Analysis of Groundwater Levels and Assessment of Regional Groundwater Drought: Ghataprabha River Basin, India

Abstract: Groundwater drought is a relatively new concept, particularly in the Indian subcontinent, where groundwater levels are declining rapidly. The present study focuses on understanding the trends in groundwater levels and evaluates regional groundwater drought characteristics in the drought-prone Ghataprabha river basin, India. Cluster analysis was performed on the long-term monthly groundwater levels to classify the wells, and the Mann–Kendall test was accomplished to investigate the annual and seasonal groundwater-level trends. Standardized Groundwater level Index (SGI) was used to evaluate groundwater drought. Significant decreasing trends were observed in more than 61% of the wells in the study area with average decline of 0.21 m. Results of the SGI analysis showed that the wells of clusters 1 and 2 experienced recurrent droughts, which can be attributed to diminishing rainfall and over-exploitation of groundwater resources. The outcome of this study provides valuable information about the long-term behavior of regional groundwater levels which, in turn, helps to establish an operative groundwater management strategy for upcoming droughts.

Development of a New Hybrid Multilevel Inverter Using Modified Carrier SPWM Switching Strategy

Abstract: This letter presents a single-phase cascaded transformer based multilevel inverter with a modified carrier-based level shift sinusoidal pulse width modulation (LS-SPWM) technique The developed topology has two bridges with individual low frequency transformers The bridges can generate quasi-square waveform and pulse width modulated waveform independently and energized the two transformers whose secondary terminals are cascaded to attain 19-level output voltage waveform across the load The anticipated configuration has the least number of components to reduce the cost and enhance the reliability of the converter for medium power applications with inbuilt isolation Furthermore, this letter presents the most common LS-SPWM technique with a new carrier to enhance the fundamental magnitude and shifts the dominant harmonics into three times of the traditional strategy for the same modulation indices The performance of the proposed topology is validated with experimental results