Sri Sivasubramaniya Nadar College of Engineering

About: Sri Sivasubramaniya Nadar College of Engineering is a based out in . It is known for research contribution in the topics: Crystal & Single crystal. The organization has 3745 authors who have published 4329 publications receiving 35038 citations.

A Compact Frequency-Reconfigurable Antenna With Independent Tuning for Hand-Held Wireless Devices

Abstract: This communication presents the design of a compact loop antenna with independent frequency tuning. The proposed antenna consists of a feed line fed by a $50~\Omega $ coaxial probe and four resonating arms on the adjacent sides of the feed line. The two outer resonating arms are directly coupled to the feed line and the other two inner resonating arms are coupled to the outer arms. The proposed antenna has a footprint of 25 mm $\times 10$ mm $\times0.2$ mm. The designed antenna operates at 0.9, 2.4, 3.5, and 5.5 GHz. Each of these bands is individually tuned using varactor diodes. Thus, the aggregation of these tunable bands provides wide bandwidth. The impedance bandwidth and percentage bandwidth of the antenna are 270/1000/400/700 MHz and 33%/47.6%/11%/12.7%, respectively. Furthermore, the gain and efficiency of the antenna are 1.7/1.3/2.1/2 dBi and 60%/63%/65%/69%, respectively. The prototype antenna is fabricated and tested. The measured impedance and radiation characteristics of the antenna are in good correlation with the simulation results.

An IoT based remote HRV monitoring system for hypertensive patients

Abstract: Heart Rate Variability (HRV) is a measure of variation in the time interval between consecutive heart beats. HRV analysis is highly sensitive for risks linked with Cardiovascular disease, Diabetic Mellitus, disease states associated with Autonomic Dysrhythmia such as Hypertension and a large array of chronic degenerative medical condition. Sensitivity of HRV towards various medical condition accounts for its increased usage by doctors as a diagnostic, prognostic tool and to evaluate the effectiveness of the treatment offered. Often borderline hypertensive patients with and without history of a cardiac event are subjected to stroke as well as cardiac mortality at high risk. Monitoring of HRV parameters for such cases of high risk will prove useful in providing adequate medical care at needed times. In this paper, the authors propose a low-cost and easy to use Remote HRV Monitoring System based on the Internet of Things (IoT) technology for borderline Hypertensive patients. In the proposed system, HRV parameters are derived using Wireless Zigbee based pulse sensor. Arduino transmits patient data to server using MQTT protocol. The application server collects HRV data and plots graphs. In case of an emergency situation, the care taker and doctor are intimated through Short Message Service (SMS) for providing adequate medical help. While there are currently no HRV analysis systems that alerts at times of high risk for hypertensive patients along with the aid of a remote doctor, the proposed system aims at achieving the same. The proposed system combines the dual benefits of Zigbee and WiFi technology. By doing so, it successfully fulfils all the ideal traits of a remote health monitoring system in terms of low-cost, long range, security, promptness and easy-to-use that serves in saving lives.

Protection of Microgrid through Coordinated Directional Over-current Relays

Abstract: Microgrids integrate distributed energy resources to provide reliable, environment friendly and economic power to small/medium sized urban communities or to large rural areas. Due to the existence of generators at all levels of the distribution system and two distinct operating modes, i.e. grid connected and islanded modes, the fault currents in a system vary substantially. With appropriate relay coordination they gain the ability to island generators and loads together. This has a potential to provide a higher local reliability than that provided by the power system as a whole. The protection scheme implemented addresses the existing protection challenges encountered due to the presence of both distributed generators and inverter interfaced distributed generators in the same system. The proposed protection scheme equipped with directional overcurrent relays is tested using ETAP on a microgrid that consists of distributed energy resources like photovoltaic arrays, wind, diesel generator and micro hydro turbine for various fault locations.