Informatics Publishing Limited

G. Malathi ¹, S. P. Umayal ²

Affiliations
1 Drives in Sethu Institute of Technology, Kariyapatti, IN
2 Department of M.E Power Electronics and Drives at Sethu Institute of Technology, Kariyapatti, IN

Abstract

A Bridgeless SEPIC rectifier for power factor correction with low conduction losses and load regulation is proposed. The proposed SEPIC rectifier can achieve low conduction losses by provides two semiconductor switches at any time of conduction. This Sepic will act in DCM mode. The DCM operation gives additional advantages such as, zero-current turn-off; zero-current turn-on in the power switches in the output diode and reduces the complexity of the control circuitry .The output to input relation is controlled by PI controller. The proportional controller checks the error between actual and reference voltage. The integral controller will compensate this error by comparing the error with repeated sequence.DCM is preferred to produce almost unity power factor. At any time of voltage regulation line side power factor is maintained.

Keywords

Bridgeless Rectifier, Cuk Converter, Power Factor Correction (PFC), Rectifier, Sepic Converter.

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G. Malathi ¹, V. Shanthi ², V. R. Bhupathi Raju ¹

Affiliations
1 Department of Computer Applications, Velammal Engineering College, Affiliated to Anna University, Chennai, IN
2 Department of Computer Applications, St. Joseph College of Engineering, Affiliated to Anna University, Chennai, IN

Abstract

Gestational Diabetes Mellitus is a condition in pregnant women that affects the normal fetal growth and complicates the development of placenta. This study uses the ultrasound placenta images to calculate the volume of placenta. The large placentas are normally indications of gestational diabetes mellitus. Evaluation of the volume of placenta during the routine ultrasound scan can identify placenta complicated by diabetes mellitus. Placental volume is calculated using the linear measurements of placental thickness, height and width using the concave-convex Hull formula. Based on these measurements the placenta can be classified as normal or abnormal placenta. The abnormal placenta is further classified into placenta complicated by Gestational Diabetes Mellitus and the placenta complicated by other reasons. The estimation of placental volume can identify the fetal risk in conditions of gestational diabetes mellitus. This would help to diagnose the complications at the earliest which would minimize the fetal loss, birth defects and placenta abruption.

Keywords

Placenta, Ultrasound, Linear, Volume, Gestational Diabetes Mellitus, Thickness, Height, Width, Concave-Convex Hull, Haralick Features.

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S. Rajkumar ¹, G. Malathi ¹

Affiliations
1 School of Computing Science and Engineering, VIT University, Chennai - 600127, Tamil Nadu, IN

Abstract

Objectives: The objective of this paper is to analyze the different image quality metrics by testing and comparing with different distorted set of satellite images. Methods/Statistical Analysis: In this paper, we propose the methods for analyzing the quality of real time images that are corrupted due to different distortions. The several quality metrics are applied and ultimately the best metrics are derived based on the type of degradation. Different metrics such as metric based on single image and metric based on two images have been tested with different real time satellite images from NASA data sets. Findings: This framework will help to identify the metrics in order to prove the proposed filtering schemes that are applied to the corrupted images. Based on the results, we have concluded the characteristics of different quality metrics and further we successfully identified the quality metric appropriate to various distortions. Application/Improvements: The proposed quality metric analysis is used to estimate the performance of any filtering schemes which are used to enhance the quality of any real time images such as remote sensing field.

Keywords

Assessment, Blur, Gaussian, Metrics, Quality, Satellite Images, Salt and Pepper.

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