Thesis & Report (Bachelor of Science in Electronics and Communication Engineering)

Permanent URI for this collectionhttps://hdl.handle.net/10361/691

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Wearable hand rehabilitation system for post-stroke patients
(BRAC University, 2024-10) Adhikary, Upama; Hoque, Zafira Tahseen; Rafi, Rifat Rahman; Rifat, Md; Azad, AKM Abdul Malek; Saima, Sabrina; Rafi, MD Rafiqul Islam; Department of Electrical and Electronic Engineering
Stroke is a leading cause of long-term disability, significantly affecting hand mobility and strength among survivors. Traditional rehabilitation methods are often inaccessible due to high costs, limited availability, and patient engagement challenges. Therefore, this research introduces a wearable hand rehabilitation system designed to address the specific needs of stroke survivors, offering an affordable, efficient, and portable alternative to conventional therapy. The system leverages modern technology to enhance hand mobility, allowing patients to independently perform rehabilitation exercises while enabling doctors to remotely access and monitor exercise data for personalized feedback. By comparing the system's effectiveness against standard rehabilitation techniques, this study highlights its superior potential for improving recovery outcomes in stroke patients. positioning it as a promising tool for facilitating comprehensive and efficient stroke recovery.
Performance analysis of a wireless communication network using MIMO system
(BRAC University, 2021-09) Saha, Siddharth; Shajib, Kamrul Hasan; Saha, Archita; Bhuiyan, Md Belal Hossain; Mahmud, Tasfin; Department of Electrical and Electronic Engineering
The rate at which data transmits from source to destination is a major aspect of wireless communication networks. It is desirable to transmit data bits with no possible errors but due to channel constraints and system designing; bit error occurs thus the users cannot get the information at their desired speed. In this paper, the methods for improving bit performance of a multiple input multiple output communication system is investigated. By using space time block coding at the transmitter side of MIMO we can significantly improve bit performance by reducing inter symbol interference. Side by side the effect of maximum ratio combining at the receiver side to improve bit rate was also studied. Antennas of wireless communication systems are battery limited, so it is important to allocate power efficiently. In this regard, water filling algorithm for power allocation was investigated. Waterfilling algorithm uses Singular value decomposition method to decompose MIMO channel matrix into parallel sub channels. After knowing the noise information gain of parallel sub channel gains, power is allocated accordingly to ensure power efficiency. Later, effect of different modulation scheme on Alamouti STBC MIMO system was investigated. It was found that high order modulation schemes has a better throughput but bad bit performance than a lower order modulation schemes.
Internet of Things (IoT) based air quality index measurement system for Dhaka city
(BRAC University, 2021-10) Aurangajeb, Raoha; Karmaker, Sajib; Kamal, Md. Ridhwan; Tasdid, M. Sadman; Khan, Shahidul Islam; Department of Electrical and Electronic Engineering
Air pollution is a burning question for the environment nowadays, requiring paramount interest. Air pollution can be controlled by monitoring the level of pollutant gases (NO2, SO2, CO2, CO, O2, PM 2.5, PM 10, etc.) in a periodic manner. Sensing air quality is a major concern for environmental monitoring. In this study, the air quality has been measured for 5 points of Dhaka city by using air quality sensors using IoT platform. The sensed data is then sent to the Thinkspeak cloud platform. The collected data is first processed and then analyzed for obtaining the value of the air quality index (AQI). The generated results are then visualized by the graphical representation. On the basis of this, an individual can take precautionary measures for a healthy life. Finally, the overall scenario for a monthly analysis has been depicted in a location-based mapping. The studied areas are Mirpur 6, Uttara Sector 6, Mohakhali Wireless, Nikunjo 2, and Uttara 12. All the setups are located in the residential areas. The result shows that the Mohakhali has the highest AQI value which is unhealthy for the inhabitants according to the standard index. The real-time data can be observed remotely by using the IoT platform. The output of the study can be further utilized for public health monitoring purposes.
Optical mapping of Tip-Enhanced Raman Spectroscopy (TERS)
(BRAC University, 2017) Mishuk, Md. Nasimuzzaman; Rahman, Dr. Md. Mosaddequr; Hoque, Md. Anamul; Department of Electrical and Electronic Engineering
Imaging technique with high-sensitivity and high-spatial-resolution at single molecular level is always a desired aspect to the researchers. In association with scanning probe microscopy and surface-enhanced Raman spectroscopy (SERS), a new technology has shown the light of hope to achieve what was thought as unachievable earlier, named tip-enhanced Raman spectroscopy (TERS). An essential tip is used in TERS instead of rough metal film. This tip gives the information of the topology of the target molecule by scanning probe technique and can magnify the Raman signal largely without any special sample preparation. Between this metal tip and surface, a ‘hot-spot’ is formed when the laser beam is applied. Conventionally in TERS theory, Raman signal enhancement factor is approximately equal to the fourth power of the local field enhancement factor at the ‘hot-spot’. In this thesis, the localized electric field in the vicinity of the metallic tip of TERS was examined and the effect of different polarization of source in mapping TERS was observed with Finite-Difference Time-Domain method (FDTD) simulation. For this simulation, tip radius and distance between tip and substrate were kept constant and incident wavelengths were varied. For the sake of simulation, Lumerical simulation software was used because of its high accuracy.
RouteFinder : real-time optimum vehicle routing using mobile phone network
(BRAC University, 8/28/2014) Ahmadullah, Najiba; Islam, Shahpar; Ahmed, Tarem; Department of Electrical and Electronic Engineering
Road traffic congestion is a major issue in most mega cities. The traffic jams are often exacerbated by drivers habitually following the same routes. A real-time, optimum vehicle routing system that takes traffic density into account can be a possible solution to this problem. This paper presents RouteFinder, a system of providing real-time traffic density mapping on the driver’s smartphone using an in-vehicle module built using inexpensive components that communicates with the existing mobile telephone network, to enable the driver to choose the least congested route to a desired destination. The hardware module contains the essential elements of a cellular handset such as a SIM card. The location of the vehicle is determined through a standard triangulation algorithm performed using signals from the three nearest cellular base stations, and the location information is constantly updated at relevant Home Location Registers (HLRs) / Visitor Location Register (VLRs) at the telecom service provider using an intermediate MySQL database. An Android application developed for the driver’s smartphone shows the present locations of all vehicles in all routes from the origin to the selected destination, with colour codes distinguishing between moving and stationary vehicles. We have implemented our device in 10 vehicles in Dhaka city. Our sample calculations have shown significant savings not only in terms of time, but also in fuel consumption.
Comparison analysis of wireless network audits using open source tools
(BRAC University, 9/1/2014) Islam, Nuzhat Nuary; Zareen, Fahmida; Kazi, Sadia Hamid; Department of Electrical and Electronic Engineering
Wi-Fi, also spelled Wifi or WiFi, is a popular technology that allows an electronic device to exchange data or connect to the internet wirelessly using radio waves. WiFi has a lot of advantages, they are easy to set up and inexpensive. They're also unobtrusive. At the same time, a well-designed and secure installation of a WiFi network is not a trivial task. Many companies therefore need professional help to audit their WiFi deployments or pilots, and ensure that their use of this new technology is not done at the expense of security and performance. Many tools exist to enable security professionals to do Wi-Fi networks surveys, ranging from "Free" Open source tools, to sophisticated commercial products. Nowadays most of our industries are using wireless networks for communications, and security is a big issue here. But it has been seen that most of the industries do not monitor or audit their network, as the trend is that open source tools are not for professional purpose. And the professional and commercial audit tools are expensive for some of the industries in our country. But there are some of the open source tools for detecting, monitoring and penetrating which are very efficient, for example Wi-Fi networks are Kismet, NetStumbler ,Wireshark , WiFiFoFum , Aircrack and many more. The intention of this thesis is to do a comparison analysis of the top most open source audit tools and map them according to different industries of our country. The comparison analysis was done by practically installing the tools and using the tools to audit networks at different sites and then mapping the features to the requirements of the most popular sectors of industries of our country.
Hybrid wireless mesh network
(BRAC University, 2013-12) Hossain, Foez Md Iqbal; Imran, Misbah Uddin Md.; Ahmed, Md. Saleh; Kazi, Sadia Hamid; Department of Electrical and Electronic Engineering
In the last few years, there has been an immense influence of wireless networks in our daily life. Especially, wireless mesh network has got a prominent attention in academic research and commercial deployment as well. We are proposing Hybrid Wireless Mesh Protocol (HWMP) to enhance the performance of wireless mesh networks as statistic shows that for WMNs, the proposed routing protocol outperforms other well-known protocols in terms of different parameters like packet delivery fraction, network throughput and end-to-end delay. HWMP defined in IEEE 802.11s, is a basic routing protocol for a wireless mesh network. It is based on AODV and tree-based routing. In HWMP, on-demand routing protocol is used for mesh nodes that experience a changing environment while in a fixed network topology proactive tree-based routing protocol is an efficient choice for mesh nodes . Moreover, wireless mesh networks provides facilities such as ease of installation, cost effective deployments, a high level of performance in coverage area and capacity, network flexibility and self-configuration capabilities. These benefits enable seamless communication in underdeveloped areas such as rural communities. Congestion control and optimal route selection in the network layer is gained through routing protocol optimizations. Here, Network simulator 3(ns-3) has been used to simulate our particular protocol in the simulation model. Simulation (ns3) results show that the proposed hybrid wireless mesh protocol (HMWP) significantly improves the performance of wireless mesh networks than other protocols.
A comparative study of DC/AC pure sine wave inverters
(BRAC University, 2013-12) Bintu, Nusrat Khan; Muhammad, Labiba; Anjum, Navid; Ahmed, Supriyo Shafkat; Department of Electronics and Communication Engineering
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.
Analysis of Rectifier circuits with power factor correction
(BRAC University, 2014-01) Hassan, M. M. Emran; Sultana, Afrin; Akther, Sunjida; Abedin, Amina Hasan; Department of Electrical and Electronic Engineering
Power Factor, the ratio between the real power and the apparent power forms a very essential parameter in power system. It is indicative of how effectively the real power of the system has been utilized. With rapid development in power semiconductor devices, the usage of power electronic systems has expanded to new and wide application range that include residential, commercial, aerospace and many others. Power electronic interfaces have proved to be superior. However, their non‐linear behavior puts a question mark on their high efficiency. The current drawn by the interfaces from the line is distorted resulting in a high Total Harmonic Distortion(THD) and low Power Factor(PF). Individually, a device with harmonic current does not pose much serious problem however when used on a massive scale the utility power supply condition could be deteriorated. Other adverse effects on the power system include increased magnitudes of neutral currents in three‐phase systems, overheating in transformers and induction motors etc. Hence, there is a continuous need for power factor improvement and reduction of line current harmonics. Development of new circuit topologies and control strategies for Power Factor Correction (PFC) and harmonic reduction has become essential. This project aims to develop a circuit for PFC using passive filters.
Design and optimization of an UWB microstrip patch antenna using dielectric substrates Duroid 5880 And FR4
(BRAC University, 2014-01) Chowdhury, Nusrat Tasnufa; Chowdhury, Dilruba; Saha, Pran Kanai; Department of Electrical and Electronic Engineering
No longer new in wireless technology; the ultra wide band (UWB) radio transmits large amounts of digital data over a wide spectrum of frequency bands (>500MHz) at distance up to 230 ft at very low power (< 0.5 mW), As well as can carry signals through doors or obstacles; that tend to reflect signals at limited bandwidths and at higher power. The low power spectral density limits the interference potential with conventional radio systems. High bandwidth can allow very high data throughput for communication, or high precision for location and imaging devices. The Shannon‟s Theorem given by, Channel capacity; C= B. ln(1+ SNR); Where, B is bandwidth shows us that the channel capacity increases with the channel bandwidth. Design and development of a rectangular micro strip slot patch antenna for short distance ultra wideband communication has been demonstrated in this project. Different antenna family for wide band communication has been studied. Suitable antenna architecture is to be proposed for ultra wide band application analyzed using HFSS 15. Result required 1 GHz bandwidth for the applied substrate thickness 5 mm and resonance frequency 5 GHz, the impedance matched and voltage standing wave ratio (VSWR) closest to 1. However, using different sizes, shapes, allocation and number of slots on patch to obtain the foremost required bandwidth for UWB application was the challenging part. The architecture has been developed to transmit over a bandwidth of 0.96 GHz which is close to required 1 GHz, having VSWR of 1.2202. Further modifications of the design can optimize the antenna for best result.
Automating ICU emergency signaling
(BRAC University, 2013-08) Bengali, Rashida; Yeazdani, Nabila; Zaman, Naima; Ahmed, Tarem; Department of Electrical and Electronic Engineering
In this thesis, a recursive algorithm based on kernel mapping is applied to develop an automated, ICU Signaling. The method is portable and adaptive, and has lower complexity. Streams of different medical parameters are used to identify normal and abnormal conditions of individual patients in ICU. Using a system as such, the slightest of anomaly deviated from the norm, can be detected and alarmed, so that the medical team can take immediate and emergency action.
Museum security system
(BRAC University, 12/15/2012) Muhtadi, Taseen; Amin, Nurul; Tabassum, Musrat; Sarwar, Sayed Shakib; Department of Electrical and Electronic Engineering
A comprehensive security system incorporating motion sensors and laser sensors activated and deactivated by a password. The security system is designed to protect a valuable object. Access to the room can only be gained by entering the correct password. Upon unauthorized entry into the room or coming into close proximity of the object or removal of the object in question from its place would sound the alarm.
Design and animation of automated alternative solar water heater system at the BRAC University roof top by using solid works and implement the controller using GAL technology
(BRAC University, 2012-05) Chowdhury, Ahasanul Haque; Azad, AKM Abdul Malek; Department of Electronics and Communication Engineering
The objective of the thesis is to design the “alternative Solar Water Heater with Automated control system”, which is developed by CARG at the roof top UB building, using “SolidWorks 2012” software. Initially, I made a 2D model of the roof top project in SolidWorks. The sketch will consist of geometry and dimensions to define the size and location of the system. The dimensions in the sketch can be controlled independently. Finally, that drawing will be created of the designed model. Views are automatically generated from the SolidWorks model (3D) and notes, dimensions and tolerance can be easily added to the drawing as needed.
Performance analysis of a Multi-tone direct sequence code division multiple access (MT-DS-CDMA) system over a nakagami-m fading channel
(BRAC University, 2011-05) Salma, Umme; Tanni, Tanzina Rahman; Mourin, Nishat Jahan; Islam, Humayra; Majumder, Satya Prasad; Department of Electrical and Electronic Engineering
Performance analysis has been carried out for a multi-tone DS-CDMA wireless communication system over a faded channel considering the channel limitations. The analysis is based on MT-DS-CDMA system and a rake receiver with maximal ratio combining (MRC) diversity combining technique. The expressions for the output signal and (Multiple Access Interference) MAI has been derived for the above system model. The expression for the SNR and the unconditional BER at the output of the receiver has also been derived. The performance results has been evaluated numerically in terms of SNR, BER and the power penalty due to channel effect. The optimum system design parameters have been found for the numerical results. Also simulation works has been done for different parameters and comparison has been done with one of the most effective CDMA scheme among all the systems.
Performance and analysis of DC-AC pure sine wave inverter
(BRAC University, 12/8/2010) Purification, Paul; Azad, A.K.M Abdul Malek; Department of Electrical and Electronic Engineering
Energy crisis are of special attention in today's world. The unending usage of non-renewable energy sources will bring an end to the limited resources in near future. In order to preserve the resources, several alternative renewable sources have been in use these days. The power generated from the renewable sources, like solar energy, produces is a DC power which can be stored in batteries. This DC power needs to be converted to AC power as most of the appliances used in our daily life are dependent on AC power. To overcome this obstacle, DC-AC Inverter took birth.Inverter s can be categorized into three groups: Square wave, modified sine wave and pure sine wave. Considering power wattage, efficiency and harmonic content, pure sine wave inverters has proved to have the best quality among the three types. The control circuit for pure sine wave inverter produces sinusoidal pulse width modulation. There are two basic topologies to generate pulse width modulation¬Topology 1: Analog Control circuit and Topology 2: Microcontroller based control circuit.In this thesis project, performance of both topologies used in inverters has been analyzed and a DC-AC pure sine wave Inverter using the Analog control circuit (Topology 1) has been implemented.
Alternative solar water heater for domestic purpose
(BRAC University, 2009-08) Sadrin, Samara; Hossain, Maherin; Mohith, Ehsanul; Azad, A.K.M.; Department of Electrical and Electronic Engineering
In this report we aimed to incorporate solar energy in the domestic household. We designed a system that would allow the user to attain hot water in an efficient and cheap manner. Every household has domestic electric water heaters which consume a lot of electricity. Nowadays, there is a severe electricity crisis and therefore alternative resources must be looked into. This automated system would allow the user to get hot water from the solar water heater as long as the solar water heater can supply hot water above a set temperature. If the solar water heater is unable to supply water above the set temperature, then only will the electric water heater come into action. It is efficient because our controller ensures that the solar water heater is used to supply hot water 80% of the time, and the rest 20% will be supplied by the electric water heater. It is cheap because, our system runs on solar energy which is abundant and free. It uses very small amount of electricity and therefore, reduces the expenses for the user.
Security issues in VANET
(BRAC University, 4/16/2010) Sakib, Rizwanul Karim; Reza, Bisway
A Vehicular Ad-Hoc Network or VANET is a form of Mobile Ad-Hoc Network or MANET which provides communication between vehicles and between vehicles and road-side base stations. A vehicle in VANET is considered to be an intelligent mobile node capable of communicating with its neighbors and other vehicles in the network. VANET is different from MANET due to high mobility of nodes and the large scale of networks. Security and privacy are the two main concerns in designing a VANET .Although there are many proposed solutions for improving securities in VANET but security still remains a delicate research subject. The main objectives of this paper is to improve the security issues in VANET.The preliminary efforts were focused on the potential applications, possible attacks, security requirements and the literature review. The long term goal of this project is to come up with an entirely new solution that can be implemented in designing a VANET.

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