Quazi Delwar Hossain
Chittagong University of Engineering and technology

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Internet of things based fall detection and heart rate monitoring system for senior citizens Md. Hasib Sarowar; Md. Fazlul karim Khondakar; Himaddri Shakhar Roy; Habib Ullah; Riaj Ahmed; Quazi Delwar Hossain
International Journal of Electrical and Computer Engineering (IJECE) Vol 12, No 3: June 2022
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v12i3.pp3204-3216

Abstract

Falls cause the maximum number of injuries, deaths, and hospitalizations due to injury for senior citizens worldwide. So, fall detection is essential in the health care of senior citizens. Present methods lack either accuracy or comfortability. The design of fall detection and heart rate monitoring system for senior citizens has been presented in this paper. The hardware interface includes wearable monitoring devices based on a tri-axial accelerometer and Bluetooth module that makes a wireless connection by software interface (mobile application) to the caregiver. Global positioning system (GPS) can also track the location of the elder. For detecting falls accurately, an effective fall detection algorithm is developed and used. The performance parameters of the fall detection system are accuracy (97.6%), sensitivity (92.8%), and specificity (100%). A pulse sensor is used for monitoring the heart rate of the elder. The device is put on the hips to increase comfortability. Whenever the elder's fall is detected, the device can send information on fall data and heart rate with location to the respective caregiver successfully. So, this device can minimize the injury and health cost of a fallen person as a victim can get help within a short time.
Improved Solar Photovoltaic Array Model with FLC Based Maximum Power Point Tracking Nur Mohammad; Md. Asiful Islam; Tarequl Karim; Quazi Delwar Hossain
International Journal of Electrical and Computer Engineering (IJECE) Vol 2, No 6: December 2012
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (3222.593 KB)

Abstract

This paper presents an improved model of solar photovoltaic (PV) array along with the implementation of fuzzy logic as maximum power point tracking (MPPT). The proposed PV array behavioral model is more accurate and with reduced complexity though considered discrete components. The PV array model was well verified by considering the effect of change of environmental conditions, mainly intensity of solar irradiation (insolation) and temperature. The model was tested by feed a single phase inverter. MPPT control the operating voltage of  PV arrays in order to maximize their power output as a result maximize the array efficiency and minimize  the overall system cost. Using a Fuzzy logic based algorithm, the duty cycle of the converter inserted between source and load is adjusted continuously to track the MPP and compared with the conventional perturb and observed (P&O) method for changing environmental conditions. It was found that the Fuzzy logic based method can track the MPP more precisely and rapidly than the conventional one. In P&O method, if step size of input variable is very small, the accuracy in tracking MPP is sufficient but tracking speed becomes too slow. On the other hand if the step size is increased to imitate the rapidly changing weather conditions, accuracy deteriorates and unexpected results occur due to oscillation around a mean point although tracking speed increased. But in the case of proposed FLC whatever the step size of input variable it best suited to track MPP continuously and accurately. The obtained simulation results validate the competent of the solar PV array model as well as the fuzzy controller.DOI:http://dx.doi.org/10.11591/ijece.v2i6.1328
An improved 2×2 array antenna using both-sided microwave integrated circuit technology for circular polarization Piyas Chowdhury; Nishako Chakma; Abu Hena Murshed; Md. Azad Hossain; Quazi Delwar Hossain
International Journal of Electrical and Computer Engineering (IJECE) Vol 13, No 1: February 2023
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v13i1.pp619-628

Abstract

A circularly polarized microstrip patch array antenna using both-sided microwave integrated circuit (MIC) technology with a triple feed network has been proposed in this article. The antenna elements, feed structure and both-sided MIC technology are used and arranged in such a way to obtain circular polarization alongside high gain without using an external matching circuit. The 50 Ω microstrip line is used to energize the antenna where the antenna’s total feed network is made up of both series and parallel combinations of microstrip and slot line. The antenna was realized using Teflon glass fiber substrate (εr)=2.15 with a thickness of 0.8 mm. The antenna has some splendid parameters including S11 of less than -35 dB, a gain of 12 dBi with an omnidirectional pattern and an axial ratio of 0.7 dB at the operating frequency. The antenna possesses a bandwidth of 430 MHz (4.22%) after operating at X-band in the frequency spectrum. The antenna’s simulated parameters were investigated with the help of advanced design system (ADS) simulation software in microwave momentum mode.