Chittagong University of Engineering & Technology

About: Chittagong University of Engineering & Technology is a education organization based out in Chittagong, Bangladesh. It is known for research contribution in the topics: Computer science & Renewable energy. The organization has 1200 authors who have published 1444 publications receiving 10418 citations. The organization is also known as: Engineering College, Chittagong & Bangladesh Institute of Technology, Chittagong.

Real-Time Bangla Sign Language Detection with Sentence and Speech Generation

Abstract: Sign language, the non-verbal language used by the people with hearing and speaking disability, known as the deaf and mute, to connect the bridge of communication with others. Being a visual means of communication, it deprives the mutes to communicate with people having a visual impairment. A medium recognizing sign language and converting it into text and speech could fill the gap. Recently lots of research has been on Bangla Sign Language(BdSL) classification, not on Bangla sentence and speech generation. Most of them classify either digits or alphabets and also face time delay. This paper proposes a system for BdSL recognition that can interpret BdSL from a sequence of images or a video stream and generate both textual sentences and speech in real-time. We have used YOLOv4 as the object detection model. We have also proposed three new signs for the sentence generation task and built a dataset consisting of 12.5k BdSL images of 49 different classes where 39 are Bangla alphabets, 10 are Bangla digits, and the three new proposed signs.

Stairways detection and distance estimation approach based on three connected point and triangular similarity

Abstract: Detecting stair region and estimating the distance from a camera to stair in a stair image is the fundamental step in the implementation of autonomous stair climbing navigation, as well as alarm systems for vision impaired people. In this paper, a framework is proposed for detecting the stair region from stair image utilizing some natural properties of stair. One unique property of them is, every stair step's beginning and ending horizontal edge point intersects with two vertical edge points creating three connected point. These vertical edges are stair step's height and its width edge. Another unique property is steps of a stair appear gradually increasing order from top to bottom of the stair in a parallel arrangement. For that initially, directional Gabor filter and Canny edge detector are employed on the stair image to eliminate the influence of illumination and for detecting stair edges. Non-candidate stair edges are removed by performing filtering operation. Then longest horizontal edges are extracted by using a proposed edge linking method on the edge image. After that, a search method is applied for finding stair step height and width edge point at the beginning and ending point of the longest horizontal edges. This operation is performed for detecting three connected points to validate the stair edges. In the next step, increasing longest horizontal edge segments are extracted by comparing x coordinate values of two consecutive edges end points to justify them as stair edges. Finally, from this set of horizontal edges, vanishing point is calculated to verify stair edges from other similar patterns and confirm the detection of stair candidate region. In addition, the triangular similarity is used for distance estimation from camera to stair. The proposed framework is tested using various stair images under a variety of conditions and results are presented to demonstrate the efficiency and effectiveness.

Estimation of link range and bit rate for 16 channel WDM-FSO considering atmospheric turbulence and pointing error under various weather conditions

Abstract: To meet the increasing demand of bandwidth and speed, Free Space Optics (FSO) has been emerged as a promising wireless communication technique leading behind the conventional copper wire and fiber optic communications. The capacity of this cost-effective and rapidly deployable FSO system can be increased using Wavelength Division Multiplexing (WDM) technique. Atmospheric turbulence and pointing error are two constant phenomena in FSO that affect transmitted signal strength along with different critical weather like haze, rain, snow and fog. This paper presents a complete overview of WDM-FSO system in terms of link range and bit rate considering all the impediments of Free-Space channel i.e. how long the signal can propagate and how much bit rate the WDM-FSO system can support maintaining the acceptable value of Bit Error Rate (BER) of 10−9 and Quality factor of 6 in an atmospheric turbulent channel with pointing error under various weather conditions like haze, moderate rain and foggy weather. It is found that using 5 × 10−15 m−2/3 as the value of the index of refraction structure for atmospheric turbulence and respective maximum allowable pointing error, the maximum attainable link range is 5.4km, 3.1km and 1.1km for haze, moderate rain and fog respectively at a constant bit rate of 2.5Gbps and the maximum attainable bit rate is 9Gbps, 6.5Gbps and 2.5Gbps for haze, moderate rain and foggy weather respectively at a constant link range of 2.2km for haze and moderate rain and 1.1km for fog.

Thermal deformation analysis of tabbed solar cells using solder alloy and conductive film

Abstract: Finite element analysis (FEA) has been carried out with the aim of understanding the thermal deformation characteristics of two solar cell configurations. One of the solar cell models is tabbed by lead-free solder, the other model by Conductive film (CF). A high temperature soldering process could weaken the bond and reduce the reliability of the cells because of the residual stress caused by the different thermal expansion coefficients of the materials. Moreover, solar irradiation generates temperature distribution across the surface of the solar cell, and the development of solar cells made of thinner crystalline silicon wafers will lead to the reduction in manufacturing costs. In this study, Finite element analysis (FEA) of the manufacturing process has been carried out using both solder and CF bonding. Three temperature cycles were applied to analyze different environmental operating conditions and understand how thermal cycles affect the residual stress during actual service conditions. This investigation provides a comparison of thermal deformations between solder and CF bonded solar cells in order to understand which offers substantial reliability in the long term. Also this study explores the effects of various thicknesses of the silicon wafer on the residual stress and deformation of the solar cells.

Design & simulation of hydrogen based hybrid green power system using sea water for Cox’s Bazar

Abstract: Hydrogen energy is one of the favorite choice to alternative power generation around the world. Renewable energy is the best scope to produce alternative power. Because resources are available and doesn’t make any green house effect. In this reason to establish a renewable resources (solar, wind) based hybrid system with sea water electrolysis by Proton exchange membrane (PEM) electrolyzer for the production of Hydrogen. In this proposed system PV & Wind power use for sea water electrolysis and storage Hydrogen. To meet the peak load demand Gas Turbine Generator used to produce electricity using storage Hydrogen fuel. For design, optimization & peak load demand we have chosen Diabatic beach, Kolatoli Cox’s Bazar where wind flow, solar radiation and sea water are available.