Department of Electrical and Electronic Engineering (EEE)

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2nd Generation car security system
(BRAC University, 4/12/2012) Khusbu, Nusrat Jahan; Nabila, Sarah Binte Nasir; Islam, Nushrat; Rhaman, Md Khalilur
The requirement of a car has been so vital nowadays that normal people has now been considering it more as a necessity than a luxury. Having a car automatically brings in a proper security for it. The world has so far experienced many security solutions for a car, yet car thefts did not show any sign of reduction . As such, we would like to implement a car security system that will have a lot more functions and will be more reliable than the present ones. Throughout the thesis we wish to implement the following functions: • Passive Immobilizer: This will enable locking and unlocking within a short, specified distance from the remote . The locking will automatically occur if the remote is beyond the range . Wireless communication system will be followed here. • Car Tracking System: This will basically be a GPS unit that will provide information on the car ' s geographic location by using Satellite communication. • Warning alarm: After all the security functions to access the car, still if someone illegally gets access to start the car, this warning alarm will let the people around know about the car being stolen. • Weight Sensor: The weight sensor senses the weight that sits on the car. For ay abnormally high value in the car, the sensor senses that and will light on the alarm accordingly. • Robust Jumper Alert: Where the car experiences heavy jumps or shakes this alarm will be on. The car' s present state will be compared with a reference stability level for this purpose.
2nd Generation car security system (2GCSS) : Embedded car security system
(BRAC University, 12/15/2012) Rahman, Md. Mashiur; Nahid, Md. Kudrat Ullah; Rhaman, Dr. Khalilur
In this era of technology security and maintenance has become a big question in all over the world. Wherever a developed technology is used, the question of its security and maintenance also arises. If any precious thing is lost the first thing comes in our mind is where it‟s right now. The solution can be given by a Global positioning system (GPS).Another thing which comes in our mind is the maintenance of that system. We can use sonar, alarms, and switches in various ways so that we can protect our valuable system. The world has so far experienced many kinds of modules for security and maintenance. As such we have implemented modern technologies in this security system and added all the features in a module which is more reliable and flexible while use. We have implemented the following functions in our thesis - • Real time Vehicle tracking using GPS. • Engine On/off via SMS using the GSM technology • Robust Jumper alert and warning alarm • Blind point detection using SONAR. • Parking Assistant • Passenger counter and data log
3-Dimensional mapping of underwater surface for navigation using underwater ultrasonic piezoelectric transducer
(BRAC University, 2017) Hossain, Navan Tanjeem; Khan, Rahat Mahmood; Rahman, Saifur; Khan, Dr. Md. Ziaur Rahman
In the era of modern technology, even today, the underwater surface perception and mapping is still a much vague subject. Many approaches have been carried out following the topic. In a third world country, like Bangladesh, where water body is very important part of communication, life gets hindered when visual aids are compromised during navigation. The thesis conducted works to design a system to perceive and map the underwater surface. An underwater ultrasonic piezoelectric transducer has been chosen depending on the range to be perceived. A module has been designed from scratch to excite the transducer via a microcontroller unit and supply distances for mapping of the underwater surface. A program has also been developed to map the distances into a terrain and hereby display the distances in the form of 3-dimensional surface.
5 degree of freedom robotic Arm
(BRAC University, 2016) Iqbal, Md. Rashed; Aysha, Umme; Robyat, Tanjila; Rhaman,Dr. Khalilur
A robotic arm is one type of mechanical arm which is similar to a human arm and can do most of the works that a human arm can do. It can do various works which is very risky for a human. A robotic arm is programmable and can do the works through instructions. In today’s world robotic arms are used in industries, rescue purpose and various research works. Considering the facts we thought of designing and making some improvements in robotic arm. Our robotic arm is an arduino controlled six degree freedom robot arm which can move 360 degree and in 6 directions and can do almost all the works of gripping. First of all, the unique part of our robotic arm is, a counter weight is used here to balance the arm while some object is gripped. Secondly, it is able to move to a specific point of its workspace through x, y and z axis values automatically if the points are given. For giving command we are using Bluetooth serial communication system through an Application. This work presents a 6 degree robotic arm with a gripper, controlled with an android application and Arduino MEGA via Bluetooth to carry or load materials. Here, the app searches for the Bluetooth connection, if the Bluetooth device connected with robot is open for connection, then the android app connects with it. Then the app sends command to the Arduino MEGA connected with the robot which is the brain of the robot, this command is fetched by the Arduino MEGA and according to the command it moves the robot forward, backward, left turn, right turn, stop and it expands the gripper to pick a material, squeezes the gripper when a material is picked and it can also move the gripper in left or right direction according to need.
A comparative performance analysis among Hybrid NOMA Schemes for 5th Generation (5G) and beyond Wireless Communications
(BRAC University, 2021-01) Bal, Anindya; Nuhi, Jannatul Ferdous Chowdhury; Sur, Mousumi; Chowdhury, Arshad M.; Haider, Majumder Fazle
A full-scale implementation of 5G and beyond wireless communication systems require more effective radio access techniques. To address this issue non-orthogonal multiple access (NOMA) technique is considered as a most promising technology in recent times. NOMA is superior in terms of spectral efficiency and user density than the existing orthogonal multiple access (OMA) technique utilizing the limited resources, though NOMA allows controllable interferences by non-orthogonal resource allocation. Successive Interference Cancellation (SIC) can efficiently mitigate the impact of interference when implemented massively, but it raises computational complexity significantly, hence, reduces energy efficiency. In order to alleviate the drawbacks of NOMA, hybrid NOMA schemes have been proposed in recent research works. This thesis work focuses on comparative performance analysis among hybrid NOMA schemes such as MIMO-NOMA, NOMA-GSSK and STBC-CNOMA. The purpose of the work is also to recommend the best suited hybrid scheme for next generation wireless networks. Numerical analysis and simulation results validate the superiority of the NOMAGSSK scheme in terms of bit error probability and spectral efficiency than other two promising schemes. The findings also suggest that STBC-CNOMA certainly outweighs other two schemes considering system complexity and energy efficiency.
A comparative study and performance analysis of poly and mono Si photovoltaic modules
(BRAC University, 2019-08) Islam, Mohaimenul; Rahman, Md. Mosaddequr
Interest on generating power from photovoltaic (PV) system is increasing day by day. This study investigates the performance of commercially available poly and mono Si photovoltaic (PV) modules under different temperature and illumination conditions. While mono Si module shows better solar cell features in terms of series resistance, reverse saturation current and fill factor. On the other hand, the photo generated current and output power of mono Si module are found to be much lower than those obtained with poly Si module. Lower photo-generated current in mono Si module is attributed to higher recombination in thick bulk layer of mono Si cell, which is probably due to the lower than required crystal grade of mono Si module. Furthermore, the performance of power generation from PV systems can be affected by certain factors which can be detected early by proper monitoring technique. Infrared (IR) thermography is a well-known non-destructive technique which can detect localized heating and identify hotspot. In this study active thermography has been applied to detect possible anomalies considering visual inspection. One of the main findings is that PV modules have some defects which is visually observable. Junction box creates heat that may impact on the module performance. The findings of this work suggest the importance of preventive maintenance for quality control of commercially available PV modules.
A comparative study of AI-based and signal processing techniques for condition monitoring of power transmission networks
(BRAC University, 2025-09) Khalif, Abdirizak Abdullahi; Huda, A. S. Nazmul
Transmission lines are essential for transporting power over long distances as far as it is not always effective and it may also fail thus putting the flow of power at risk and the people who depend on power at risk as well. This is why the maintenance of their reliability and efficiency is of paramount importance in energy infrastructure of the contemporary world. This research aims at exploring the detection and classification of faults in power networks. Here, a novel hybrid model, DWT- CNN-BiLSTM, is presented which combines signal processing and deep learning and compares it with the classic machine-learning and deep learning approach. A dataset of 11,000 current and line-voltage samples that were provided in MATLAB SimPowerSystem evaluated the proposed model. Wavelet transform breaks down the signals by time-frequency, which represents transient faults as well as attenuating noise. The resulting coefficients are then inputted into a CNN, which produces spatial features, which are then inputted into a BiLSTM that yields bidirectional time information. One last Softmax layer allows fault detection and classification of multiple classes reliably. It is a robust, high-accuracy end-to-end pipeline that can be deployed in real time, and the accuracy of fault-detection is 99.86 %, and the accuracy of classification is 93.75%. Further proof of the effectiveness of the hybrid model is that the hybrid model surpasses single-method machine-learning and Deep learning baselines in terms of precision, accuracy and recall. Such findings show that the model can be applied in practice in real-time as a way of enhancing system stability in power-generation, predictive maintenance, or operational resiliency.
A comparative study of DC/AC pure sine wave inverters
(BRAC University, 2013-12) Bintu, Nusrat Khan; Muhammad, Labiba; Anjum, Navid; Ahmed, Supriyo Shafkat
A power inverter or inverter is an electrical power converter that changes direct current (DC) to alternating current (AC). The converted AC can be at any required voltage and frequency with appropriate transformer, switching and control system. In under developed countries, the ever increasing reliance on electrical and electronic devices which utilize AC power highlights the problem associated with the unexpected or sudden loss of power due to electrical load shedding. Therefore, there is a need of inexpensive and reliable pure sine wave inverter to backup sophisticated electronic devices like medical devices and as well as for household appliances like fan, television, tube-lights etc. It has been noted that today’s pure sine wave inverter produces total harmonic distortion (THD) of about 3% [1]. It is due to this THD, the lifetime of other electrical devices like fan, tube-light etc. decreases significantly [2]. This thesis aims to compare and analyze the total harmonic distortion, efficiency and cost effectiveness of different inverters from different renowned companies and finally to propose a design of a pure sine wave inverter with less total harmonic distortion and with greater efficiency than usual. Thus, it will have less effect on the lifetime of any electrical devices such as fan, tube lights etc.
A comparative study of intelligent reflecting surface and relay in satellite communication
(BRAC University, 2021-01) Khan, Mohammed Rabbul Hossain; Ziad, Muhammad Omar; Chowa, Sumaiya Mazed; Mehedi, Md. Mohiuddin; Sabuj, Saifur Rahman; Mohsin, Abu S.M.
One of the most significant technologies for worldwide telecommunication is satellite communication. The fundamental advantage of satellites is their extensive range. Low Earth Orbit (LEO) satellites have the least propagation delay and the best data rate when compared to other satellite types. Another recent technology being implemented in communication systems are Unmanned Aerial Vehicles (UAVs). UAVs provide a new dimension to the world of communication. The principal advantages of UAV are their high mobility and versatility. In this thesis, we build a communication system consisting of ground base stations, UAVs and LEO satellites. We then implement two communication schemes in our system and analyze their performance to find out the better performer. The two communication schemes that are employed are a Decode and Forward (DF) relay assisted scheme and an Intelligent Reflecting Surface (IRS) assisted scheme. In our results, we determined that when considering optimum power transmission and energy efficiency at the same achievable rate, the IRS scheme provided a much better performance than the DF relay scheme. The results of our thesis conclude that the IRS scheme is much more superior to the DF relay scheme.
A comparative study of listen before talk categories using machine learning
(Brac University, 2023-04) Adhikari, Rudra Lal; Sabuj, Saifur Rahman; Bhuian, Mohammed Belal Hossain
The cellular industry is seeking solutions to efficiently utilize the available spectrum band due to the rapid growth of wireless traffic and technological advancements. One potential solution that has gained attention is implementing Long Term Evolution (LTE) with unlicensed spectrum (LTE-U) using a Listen before Talk (LBT) approach, as prescribed by international regulators. To ensure fair channel access for co-located networks, it is crucial to establish a coexistence strategy that incorporates expected traffic requirements for both present and future needs. Machine learning has been recognized for its ability to automate critical wireless communication network activities, gather data from multiple sources, and employ various algorithms. Thus, this project emphasizes the significance of researching LTE and Wi-Fi coexistence in unlicensed spectrum using machine learning. It provides an overview of existing LTE-U and Wi-Fi technologies, and reviews the studies that have been conducted on their coexistence. The project also discusses LBT mechanisms and their categories as defined by the 3GPP standard, as well as previous research conducted in various categories, providing a basis for future research. The study evaluates the performance of each priority class of LBT Cat 4 using the Jains Fairness with machine learning approach to determine the best coexistence priority class of LBT Cat 4 that will enhance future network performance when coexisting with Wi-Fi. Thus in wireless communication systems, machine learning can be used to optimize the LBT protocol by learning the patterns and characteristics of the communication channel. By training the large amounts of data collected from the communication channel, the network can learn to predict when the channel will be free and when it will be busy. This can help to reduce the waiting time for devices and increase the efficiency of the communication system. Moreover it help us to understand the channel sharing fairness and signal detection probability better for each of the priority class of LBT Cat4.
A comparative study of mono-crystalline and poly-crystalline silicon solar cells under different climatic conditions of Bangladesh
(BRAC University, 2016-08) Afifuzaman; Hossain, Mahmud; Rehan, Rubayet; Rahman, Dr. Md.Mosaddequr
The objective of our thesis is to analyze the performance of two types of silicon solar panels- mono-crystalline and polycrystalline under different climatic conditions of Bangladesh. Temperature, wind speed, solar irradiation affects the performance of solar panel. In our work different parameters of the solar cells such as open circuit voltage, short circuit current, series resistance of a photovoltaic cell, maximum power output point, fill factor, maximum working current, and maximum working voltage have been calculated under different temperature and illumination conditions. Experiments have been conducted in both indoor and outdoor. Series resistance was measured in dark condition. It showed an increase in series resistance for both mono-crystalline and polycrystalline solar panel with the increment of temperature. Current sensitivity of the panels was measured with the change of temperature under same illumination condition. Energy was calculated utilizing the data taken in the month of June-July. It was observed that polycrystalline panel has 4.3% energy level more than the mono crystalline panel.
A comparative study of power sources for base transceiver station
(BRAC University, 9/4/2018) Mahbub, Md. Pavel; Abedin, Syed Minhajul; Arman, Sarwar Ali; Rahman, Md. Mahmudur; Chakrabarty, Dr. Amitabha; Sabuj, Dr. Saifur Rahman
Base Transceiver Station is considered as the heart of mobile telecommunication system. Millions of phone calls, SMS and enormous number of data is being sent and received in every second through these BTS all over the world. Therefore, BTS are the devices which need to run 24/7 without being disturbed by any sort of electric crisis or shortage. Bangladesh is not fully compatible to meet the growing electricity demand of the whole country. Although it varies from day to day, on an average we predicted there are two hours of load shedding period in every distribution line of entire country. Therefore, it requires 24/7 electricity supply to all the BTS of all operators. Our concern is during the off grid period. It is found that all the operators use diesel generators for the off grid time. Our target is to compare the feasibility of using alternative power sources to minimize the cost of the system, minimizing carbon emission and reducing the dependency on the fossil fuel. Firstly, we have analyzed the previous and recent data of diesel, solar and fuel cell power sources. A new we model is proposed to combine the sources with backup of diesel generator which can minimize the cost and fulfill our target. We also analyzed the future of carbon emission which our proposed model can reduce after a certain period of years.
A comprehensive study and performance based evaluation on routing protocols of WiMAX
(© 2016 IEEE, 2/14/2017) Shabnam, Farzana; Saha, Aparna; Sobhan, Rifat Binte; Debnath, Tanmoy
Worldwide Interoperability for Microwave Access (WiMAX) technology is a subdivision of the vast field of wireless communications, which breaks the restrictions of DSL, cablemodem or T1 infrastructure based wire line of our broadband Internet connections [1]. Wireless networking has become an important area of research in academic and industry. The four high-speed intensive applications such as high-speed data, video, voice and streaming media are being served properly by the WiMAX network, which overcomes the term digital divide. It has a number of spearhead applications with at-home and dynamic internet accessibility along with large geographical coverage and relatively low expense to pursuit. Routing overhead, unidirectional link support, delay, throughput, QoS support and multicast are the analysable terms by whom we can define the WiMAX protocols. To attain best use of this technology selection of suitable protocol is very important. In our paper, most imperative protocols of 802.16 WiMAX network called AODV, DSDV and OLSR is ventilated as well as further criticized in accordance with their performance on WiMAX where AODV is a reactive (on demand) protocol and both DSDV and OLSR are proactive.
A design of feasible solar net metering system in perspective of Bangladesh
(Brac University, 2022-09) Labiba, Sumaiya Tarique; Sultana, Tanjina; Ahmed, Iftekhar; Kundu, Ankita; Huda, A.S. Nazmul; Mohsin, Abu S. M.
With the increase in demand of energy and the scarcity of non-renewable resources; it has encouraged the modern world to find alternative ways of energy production and distribution as means of a solution. The approach of solar net metering is one of the most beneficial ways for countries possessing higher potential for solar energy, especially Bangladesh. Solar net metering has been introduced in few of the countries worldwide due to the system producing green energy alongside providing financial benefits to the consumers. With net metering, the consumers obtain credits on their electricity bill with respect to the "net" amount of energy used each month which is the difference between the amount of energy the solar generation system produces and the amount of energy consumed by houses during the billing period. The excess electricity formed by the solar system is sent back to the grid. There are different ways to implement solar net metering, it includes community net metering, aggregate net metering and virtual net metering, each containing different beneficiaries for particular consumer categories.
A detailed analysis on BUCK converter in different conduction mode
(BRAC University, 2018) Shakil, Md Shaidul Islam; Abedin, Amina Hasan
A DC-DC BUCK Converter is a basic type of switch mode power converter. It has variety of application. It behaves differently in different conduction mode. In this thesis a buck converter is designed first considering the design parameters. Then the designed circuit is driven to boundary, continuous and discontinuous mode to analyze the circuit. The gain and efficiency of the circuit has also been found out. A clear picture is drawn for the theoretical and simulated circuit. For continuous mode the circuit simulation shows exact behavior but in discontinuous mode there is some discrepancies. All of these issues are covered in the thesis.
A Distanced Machinery Controlling and Monitoring Guardian
(BRAC University, 2014) Musharraf, Yaseer; Hassan, Maruf; Sakib, Shadman; Rhaman, Md. Khalilur
Every machine has a safe range of operation which includes heat emission, produced sound and vibration which an expert technician can troubleshoot most of the problems just by observing the behavior (sound, vibration, smoke, heat emission etc.) of a machine. But the machine operation complex has a hazardous environment which eventually may cause permanent health damage and it is also expensive as well. Depending upon the machine's purpose, burns, electric shocks and limb amputations are also possible. Where a machine has not been maintained properly, it may malfunction and cause injury to either the operator or other personnel on the ground or in the vicinity. To reduce these problems we are developing a special type of “monitoring system” which will allow us supervise the condition of machine in real time from a safe distance thoroughly with a full control over it.
A fabric system oriented cluster algorithm to implement a smart IOV environment
(BRAC University, 2019-08) Haider, Mohammad Rafquat; Miraj, Md Aubdulla Oalid; Anik, Neloy Hasan; Shabnam, Farzana
The Internet of Vehicles (IOV) is a comprehensive architecture for wireless communications between vehicle to vehicle, vehicle to human, vehicle to the road, and vehicle to the Internet. It allows vehicles to share information, efficiency, and safety with others as well as infrastructures using Vehicular Ad-Hoc Networks (VANET). This integration of VANET with the Internet of Things (IoT) has made the concept of IoV an emerging technology for smart cities for reducing car accidents, increasing car safety, creating an eco-friendly system and more. Being a young technology, it comes with a variety of challenges and among them, the routing protocols are a significant one that has been focused in this work. The routing protocols have been designed concerning the IoT architecture and not IoV which offers a significant challenge in routing packets as vehicle acting nodes are mobile and continuously changing position making their data to vary instantaneously and periodically. This leads to inefficient delivery of data packets from one source position to their destination. If a packet data is transferred efficiently, then it is not effective in delivery rate; failing in long-distance data transmission or a long delay in transmission. Routing protocols that are both efficient and effective require huge monetary investment. Keeping in mind all three factors - efficiency, effectiveness, and monetary resource utilization, we proposed a clustering algorithm that is based on the weight of a particular node, and also GPS positioning of all vehicle nodes will be used. The modern age has gifted us with vehichles; such as drones, cars etc; that are fitted with communication sensors. We believe that our research on clustering algorithms will provide a solution to one of the challenges of the IoV infrastructure and would help reduce the cost significantly. Overcoming these challenges will be a big step for not only the automotive industry but would also provide a new vision in communication technology. We believe it would help in generating new revenues contributing to the global economy
A highly efficient solar powered IoT based irrigation system
(Brac University, 2022-01) Khan, Farhan Hasin; Arefin, Irfanul; Ayon, Rafid Areman; Efty, Tasnimul Hasan
A low-cost sensor based smart and efficient health monitoring system for elderly people using internet of things
(BRAC University, 2020-10) Shaown, Tamanna; Hossain, Md. Shohrab
A smart and connected healthcare system is one of the most popular applications enabled by the Internet of Things (IoT). It is possible to get a rich informative indication of our physical health using networked sensors either worn or embedded in our living environments. As the aging population is constantly rising both in rural and urban areas, there is a need for an IoT-based health monitoring system to continuously monitor their health. As a result, visits to the doctors for a regular check-up is minimized and doctors can save many lives by providing valuable services in emergency purpose. In this research, a progressive method for IoT-based health monitoring system has been proposed. An architecture customized for healthcare applications is proposed and implemented as a prototype. The proposed system collects data from a patient’s body using different sensors such as an ECG sensor, Pulse Oximeter sensor, and Temperature Sensor and sends it to the cloud where it is processed and analyzed. A video surveillance camera has also been used here to continuously monitor a patients’ movement. In this study, a system is designed to frequently monitor the ECG signal, blood oxygen level, temperature, heart rate from the patient’s body using wearable sensors, and the data is stored in the database which can be accessed by authorized personnel only. When any abnormalities are found in a patients’ body an automatic email has been sent to the users and doctors for analyzing the critical conditions of the patients and provides emergency health assistance. The prototype of the proposed system for remote health monitoring has been built to demonstrate its performance advantages and the result shows that the system is efficient for remote health monitoring. It can be invoked from a remote location and in any case of abnormalities found in the patient’s body an emergency email will be sent automatically to the authorized doctors and users.
A metering network for a smart prepaid scheme under an electrical utility organization
(BRAC University, 2020-10) Rahman, Md. Ashrafur; Roy, Tridib; Saiara, Syeda Afra; Mubassir, Sheikh Tajnur; Kabir, S. M. Lutful
The present prepaid metering scheme is connected to server mainly using the GSM network. It creates an inherent dependence on mobile companies. Moreover, there is always an operational (recurring) cost to maintain different kinds of information exchange. Therefore, it will be beneficial for utility organizations if they could develop a low-cost network of their own. The objective proposed thesis work is mainly to develop a backbone metering network which once installed can be used for information exchange almost free of recurring cost. The establishment cost of the network may be high, but the benefit can justify that the utility organization can derive from it. The backbone may be composed of mixed technologies. Some portion of the network may be established with optical fibre, and some may be with copper wire, and also some may be wireless. All options and their suitability for different portions will be studies and tested to set up a standard. The work will finally be tested, and the proposed network will be up for suggestion to be implemented in the smart meter networking scheme.