Browsing by Author "Islam, Muhaiminul"

Now showing 1 - 5 of 5

Comprehensive analysis of CdS / In2S3 / ZnS buffer layers on the performance of CIGS solar cell
(DEPARTMENT OF ELECTRICAL, ELECTRONIC AND COMMUNICATION ENGINEERING, 2017-12) Hasan, Mehedi; Islam, Muhaiminul; Khan, Arif Hasan
Thin-film solar cells (TFSCs) have the potential to reach cost effective photovoltaic generated electricity. Cadmium Sulfide (CdS), Indium Sulfide (In2S3) and Zinc Sulfide (ZnS) buffer layer based Copper Indium Gallium Selenide (CIGS) solar cell offers higher efficiency with low manufacturing cost. Therefore, this thesis presents a comparative study among CdS, In2S3 or ZnS buffer layer based CIGS solar cell. The numerical study has been performed using a Solar Cell Capacitance Simulator named SCAPS-1D. The performance of CIGS solar cell is observed by adjusting the buffer layer thickness of each CdS, In2S3 and ZnS. The efficiency of CdS/CIGS solar cell is found 23.74% that is higher than the efficiency of In2S3/CIGS (23.39%) solar cell for 50 nm buffer layer thickness. This efficiency was increased further by using ZnS/CIGS structure that corresponding to an efficiency of 25.51%. It is also found that, the increase in buffer layer thickness from the optimum level degrades the performance of CdS/CIGS and ZnS/CIGS solar cells as compared to In2S3/CIGS solar cell. Therefore, In2S3 or ZnS based CIGS cell could be an ideal candidate as a substitute of toxic CdS buffer layer based CIGS solar cell.
Detection and Recognition Of Traffic Sign By Convolution Neural Network
(Department of Electronic and Telecommunication Engineering, 2022-11) Islam, Muhaiminul
Modern automated driver assistance systems that display safety information heavily rely on Traffic Sign Recognition and Detection. It is a system that enables users to instantly identify traffic signs, usually in films but occasionally only in still images. Road accidents are caused by improper interpretation of traffic signs. Moreover hundreds of people could be killed if a driver misidentifies a traffic sign in hazardous conditions like heavy rain, cloudy weather, or sleepiness. As a result, the appropriate identification of traffic signs has become a required research issue. Convolutional neural networks were employed in this study to accurately detect and classify the traffic signs. Five Keras models of CNN have been proposed, and their output has been compared. Dealing with picture noise, such as ads, parked cars, pedestrians, and other moving things or background objects that make recognition considerably more challenging, is the key difficulty of this research. The investigation has been impacted not only by the objects but also by a number of environmental factors as light reflection, precipitation, fog, etc. We have assembled our own data-set in order to undertake this research. We wandered the streets of Chittagong and took images of the traffic signs because there is no benchmark data set for Bangladesh accessible. This model provides a 98% accuracy for 39,200 photos. Numerous studies have been conducted in this area, but ours stands out since it is based on data that we have independently acquired from Bangladesh.
Mapping Out the Vulnerabilities of Migrant Women in the Informal Sector: A Qualitative Investigation in Dhaka City
(Elsevier, 2023-10-12) Sifullah, Md. Khaled; Sohel, Md. Salman; Sarker, Md. Fouad Hossain; Islam, Muhaiminul; Ahmad, Maruf; Rahman, Md Motiur
The current study seeks to explore the vulnerabilities typically encountered by female migrants in the informal sector in Dhaka city. It used a qualitative research approach, purposively selecting four areas from Dhaka city. Twenty-five semi-structured in-depth interviews during eight months of participant observation were conducted to accomplish the study objective. The authors used the capability approach theory to elucidate the phenomenon of vulnerability experienced by female migrants in the informal sector. The thematic data analyses were performed using the Granheim approach and NVivo 12 software. The findings of this study suggest that migrant women who work on the street face a number of significant challenges. These challenges include sexual assault and harassment, social stigma and cultural barriers, financial obstacles, and extortion and bribery. The authors recommend that governments provide access to state credits, social security, health insurance, and other forms of social protection for informal sector workers. The finding revealed that informal workers are often excluded from these essential benefits, making it difficult for such workers to expand their businesses or have a safety net in case of illness, unemployment, or other shocks.
Mediating Effect of Employee Engagement in the Relationship between Employee Job Satisfaction and Affective Organizational Commitment: Evidence from Hotel Industry in Bangladesh
(Faculty of Business Studies, BUFT, 2021-08-01) Islam, Muhaiminul; Islam, Saiful
Purpose: The purpose of this study is to examine the mediating effects of employee engagement in the relationship between job satisfaction and affective organizational engagement. The hotel industry of Bangladesh is selected as the context to investigate the relationship. Methodology: Using G-Power software, a sample size of 107 respondents have been chosen, who had already passed two years of their tenure in the three-stars and above hotels in Dhaka, Chattogram, Sylhet, and Cox's Bazar regions of Bangladesh. Data are collected through a survey questionnaire using the convenience sampling technique. In the analysis, the partial least square-structural equation modelling (PLS-SEM) is used preceded by the test of reliability and validity of each indicator. In this regard, SPSS 23 and SmartPLS-3 applications have been used. Findings: The findings show that job satisfaction increases the affective organizational commitment of the employees. Besides, job satisfaction boosts employee engagement, and engagement further accelerates employees' affective commitment. Hence, employee engagement performs the mediating role between job satisfaction and affective organizational commitment. Limitations: The findings of the study cannot be generalized across the country in a larger context due to the small sample size and specific to one single industry, which could be addressed in future studies. Practical Implications: This study provides useful implications for hotel managers to boost the employees' affective commitment by accelerating job satisfaction and engagement in the organization. Originality: This study also contributes to the body of knowledge by revealing employee engagement as a mediator in the relationship between employee satisfaction and commitment.
Smart Security System
(Daffodil International University, 2019-05) Islam, Md. Saiful; Islam, Muhaiminul
Human has an extraordinary capacity to identify a person in an alternate expression, condition, in light variation. Presently artificial intelligence is produced which will work like human known as Face Recognition and still now many works are processing in this field for discovering better performance. In the present time’s the major problem in our society is security issues so, they need various apart trained personnel to join the best security. These personnel, as human beings, make fault that might affect the level of security. A proposed solution to the aforementioned matter is a Face Recognition Security System, Face recognition are play an important role in difference of applications from biometrics, surveillance, security, identification to the authentication. In this paper we are make a smart security system for restricted zone where access is limited people whose faces are available in the training database. This system is composed of two parts are hardware part and software part. The hardware part consists of a Raspberry Pi, PIR sensor, Buzzer and camera, while the software part consists of face detection and face recognition algorithms software. When a person enter the Zone then Camera take a photo and software compare the trusted people. If the people are allow the zone the system are silent otherwise the system star the alarm. Experimental results explain the effectiveness of proposed security system in order to sensitive the disallowed access and authenticity by use of face recognition.