Browsing by Author "Sultana, Nigar"

Now showing 1 - 13 of 13

An IoT based smart stick for blind and visually impaired person
(BRAC University, 2021-09) Sultana, Nigar; Chakrabarty, Dr. Amitabha
Vision loss has a devastating effect on the lives of those who experience it. It affects as well as on their family, friends and society. Completely loosing or deterioration of eyesight is frightening and unbearable which leaves those affected to question their ability to maintain their independence, remain employed, and provide for themselves and their families. Loss of vision can affect one’s standard of life, his independence and mobility as well as it also has been linked to falling down, being injured, mental health issue, social function, cognition and educational attainment. In our society visually impaired or blind people is not very uncommon. At least 2.2 billion people have a near or distance vision impairment globally according to the World Health Organization (WHO). People with vision impairment have lower rates of productiv ity and workforce participation. They also have high rates of anxiety and depression. The deterioration of vision that they have to suffer from not only matter but also the overall quality of their lives deteriorates too. Vision impairment causes social isolation, a higher risk of falls and fractures. The biggest challenge for a blind per son is to navigate around places. Without a human guide he or she cannot navigate around places, especially in a new terrain. Vision impairment is associated with an increased risk of fractures which has been shown in multiple studies. This prob lem can be life threatening as well.To make life easier for someone with vision loss, SMART STICK has been developed. By detecting obstacles and identify the cur rent position of the blind and visually impaired person IoT based SMART STICK can solve many challenges. Basic requirements of the blind and visually impaired person can be met through this Stick. This IoT based Smart Stick can make a visually impaired person to walk more confidently. The study hypothesizes with the concept of a Smart Stick which allows a visually impaired person to navigate over obstacles and have less incidents.The development work of this Stick involves coding and physical installation of various types of components. The aim of this project is to build a smart stick that could communicate with its users helps him to move freely and overcome his disability.
Comparative Analysis of Different Multiplier Circuits Using Cadence at Different Circuit Design Technologies and Nodes
(IEEE, 2025-05-29) Islam, Md. Khairul; Hasan, Kayes; Sultana, Nigar; Bhuyan, Muhibul Haque
This research paper presents a comprehensive comparative analysis of the 4×4 multiplier design of Wallace, Braun array, and Vedic architectures constructed through Complementary Metal Oxide Semiconductor Field Effect Transistor (CMOS) technology using both 45 nm and 90 nm processes of the Cadence tool. Furthermore, the best-performing architecture is then built using Gate Diffusion Input (GDI) and Transmission Gates (TG) to compare the performance matrices to those of CMOS technology. The study investigates and compares these technologies’ design processes and key parameters, focusing on critical metrics, such as power consumption, area efficiency, propagation delay, and operating clock frequency. By extending its analysis, the paper compares the performance parameters of various multiplier circuits built using these technologies with the previous research findings, highlighting the advancements and efficiency improvements. The Cadence simulation results demonstrate the competitive advantages and trade-offs inherent in each technology, offering valuable guidance for designers in selecting the most suitable approach for multiplier implementations in digital systems.
Design and Implementation of Arduino Based Star Delta Starting, F/R Direction Control and Fault Protection of Three Phase Induction Motor
(International Journal of Science and Management Studies (IJSMS), 2023-01) Sultana, Nigar; Islam, S K Khairul
Three-phase induction motors have varied usage in industrial applications. At 50 Hz the most common reduced voltage starter is Star Delta. The popular applied method to minimize the start current of an induction motor is star to delta conversion. This project is designed to remotely control the starting of the induction motor through the star to delta conversion via mobile message command. The project also enables controlling of the forward and reverses motor direction along with phase fail and overload relay trip monitoring through the mobile communication system. The vital components of this project include a Two-channel relay board, a Magnetic Contactor, an Overload Relay, a Phase fail Relay, Timer Relay, Arduino Uno, and GSM SIM900A. The GSM module connected to the microcontroller sends a start command to the motor and after the system is ready the star to delta conversion happens after a certain time by an automatic timer relay. The user receives the current status of the motor and a call if any fault occurs during operation. This design of remotely Arduino controlled star delta starter, forward/ reverse motor movement, overload, and phase failure protection is safer to be used in factories and industries where the number of induction motors is widely popular.
Foot Step Power Generation: A Comparative Analysis of Multi-Array Piezoelectric Transducer Configurations
(IEEE Xplore, 2023-12) Khan, Md. Sagor; Sultana, Nigar; Himel, Moinul Alam
Energy generation from green energy sources is gaining popularity day by day. Kinetic energy is produced while humans walk or run or jump and this energy can be converted into watt power with the help of piezoelectric transducers. One crucial aspect in this process is the configuration of different numbers of circular disc piezo sensors on the small area of the foot sole. This study aims to do a comparative analysis of the connection configuration of various piezoelectric sensors and determine the best output voltage and power achieved from footsteps. Additionally, the research aims to incorporate IoT to monitor the battery status. Four types of connection configuration of circular disc piezoelectric transducers on sole pads named series, parallel, series-parallel, and parallel-series topology have been designed and tested practically. Piezoelectric sensors of 35 mm dimension with a thickness of 3.36 mm are chosen and there are eight piezo sensors placed on the sole pad in a manner where the exerted pressure is maximum. With a very simple energy harvesting circuit devoid of boost converter and voltage regulator the experiment has been conducted. The investigation revealed that a single step on the sole pad, exerting a pressure of 686.7 N, can generate a maximum of 25 V in both parallel topology and parallel-series topology configurations. Conversely, the series topology exhibits the lowest converted voltage in comparison to all other configurations. But in the case of charging the battery by giving approximately 1000 steps the stable configuration is reported as parallel topology having the maximum dc current and power. The findings will help to select the right configuration for application in low-power-consuming devices like portable health care electronic devices, batteries, and sensors.
Implementation and Customization of Customer Relationship Management (CRM) of Odoo ERP
(Daffodil International University, 2021-09-11) Sultana, Nigar
Customers are heart of any business and Customer Relationship Management (CRM) is a very import tool for customer centric modern business. Odoo as the most popular OpenSource ERP System, its CRM is very robust, flexible and offers lots of options. CRM is a process in which a business or other organization administers its interactions with customers, typically using data analysis to study large amounts of information. In this internship, I tried to implement and customize the Odoo CRM application through learning the python coding language and PostgreSQL database. In this project CRM for a real business was studied and implemented - and through the process business process and development was learnt.
Influence of digital and traditional sales marketing strategies on purchase decision-making in the IT industry
(BRAC University, 2023-10) Sultana, Nigar; Adrita, Ummul Wara
The foundation of this report is the knowledge I gained during my three-month apprenticeship at Unico IT Limited, a IT company dealing in the development of software solutions for organizations. This report is divided into three chapters in which I explore the organization, its marketing strategies, and the results of our primary research to determine the most effective approach for our business. In the section that follows, the objectives for composing this report are enumerated, along with a discussion of the learning experiences and resulting constraints. In addition, I provide a detailed company history and overview to help the reader comprehend Unico IT Limited's history, objectives, and vision. I used both primary and secondary sources to assemble this information. Conducting a comprehensive SWOT analysis, I then analyzed a variety of internal and external factors that could affect Unico IT Limited's operations. I also discussed my personal development during my tenure at Unico IT Limited and how it contributed to my skill development. In addition, I investigated the company's unique marketing requirements and how marketing strategies can affect the purchasing procedure. Understanding the sales market, generating sales practically, and applying academic concepts in this context were important goals during my tenure at Unico IT Limited. The concluding section of the report includes conclusions, recommendations, and findings, as well as concepts that support my discoveries. In conclusion, my internship at Unico IT Limited was both pleasurable and useful. I consider myself fortunate to have been a part of such a welcoming and supportive team, which encouraged a pleasant working environment in this new environment. I view this experience as a significant stepping stone in my future professional career.
Knowledge, Belief, Reality, Truth and Cloud Atlas
(East West University, 12/24/2010) Sultana, Nigar
Cloud Atlas by David Mitchell is a complex novel narrating six different stories of six different characters living in different times in different parts of the globe. What makes the novel even more dazzlingly interesting is its matryoshka doll like structure, its varied narrative style and its wide-ranging language use from different cultures and worlds. Once the first story ends abruptly, one turns the page to get sucked into the next story but remains unquestionably a bit puzzled as to how and why the previous story had stopped in the middle so unexpectedly. This happens with each story until one reaches the 6th story which is complete. After the sixth story, the remaining halves of the first five stories are continued but in reverse order with the second half of the first story coming at the very end.
Performance of Wireless DS-CDMA System with Fading
(Military Institute of Science and Technology, 2009-12) Sultana, Nigar; Rahman, Himika
This paper develops and models a DS-CDMA wireless network by simulation. It present an over view of CDMA transmission systems as compared to other multiple access schemes. The channel parameters and channel conditions are varied and the performance studied. The investigation of spreading, modulation and coding is carried out. BPSK modulation techniques are used to see the performance of the system when each is used. The BER is used as a tool to monitor the system output as SNR is varied. The AWGN channel is used in the simulation. The simulation starts with a single user and later the number of users is increased and the results evaluated. The final results are compared to the theoretically calculated results and finally concluded.
Proceedings of a workshop GARNET activities in Bangladesh: water and sanitation issues in disaster management
(International Centre for Diarrhoeal Disease Research, Bangladesh, 1996-10) Hoque, Bilkis Amin; Ahmed, Shafiul Azam; Hossain, Hasanat Iftekhar; Sultana, Nigar
This work was by the International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR,B). The ICDDR,B is supported by the countries and agencies which share concern for the health problems of developing countries. Current donors providing core support include: the aid agencies of the governments of Australia, Bangladesh, Belgium, Canada, China, Denmark, Germany, Japan, the Netherlands, Norway, Republic of Korea, Saudi Arabia, Sri Lanka, Sweden, Switzerland, Thailand, the United Kingdom and the United States; international organizations including Arab Gulf Fund, Asian Development Bank, European Union, the United Nations Children's Fund (UNICEF), the United Nations Development Programme(UNDP), the United Nations Population Fund(UNFPA) and the world Health Organization(WHO).
Proposing a new version of kerberos authentication protocol using ECC and threshold cryptography for cloud security
(BRAC University, 12/24/2017) Sutradhar, Mukti Rani; Sultana, Nigar; Dey, Himel; Arif, Hossain
Nowadays cloud computing has become inevitable in every spheres of our work, that means not only in business sectors but also in nonbusiness related task. As it has many beneficial aspects we are relying on cloud computing day by day .The more we are depending on cloud computing, the more security issues are rising. Although there are some existing protocol which are serving security for users information in cloud, at present they are not secure enough to protect users’ information in cloud. Kerberos authentication protocol is one of them which was once highly secured to authenticate data but with the passage of time and with the advancement of technology Kerberos authentication protocol is no longer that much secure. To improve its performances, many authors have proposed different kinds of model with a very common and popular public key cryptography called RSA cryptography. Of course RSA public key cryptography is good but it has some flaws which make this cryptography less efficient. As a result in our research we are trying to bring a new approach of using cloud more securely. Here, we are implementing Kerberos authentication process with Elliptic Curve Cryptography (ECC) as well as Threshold Cryptography to provide secure transaction of data which will be hard to break by third party or intruder, increase memory efficiency, cost efficiency as well as reduce the burden of computation. It acts as a third party between cloud server and clients to allow authorized and secure access to cloud services. We have also shown that why ECC public key cryptography is more appropriate than RSA public key cryptography.
Standardization of Stanford-Binet Intelligence Scale Fifth Edition (Translation and Adaptation in Bangla for Use in Bangladesh)
(© University of Dhaka, 2025-02-18) Sultana, Nigar
The Impact of IFRS on Accounting Practices: Evidence from Bangladeshi Listed Companies
(University of Dhaka, 2019-10-07) Sultana, Nigar
Trends in Opto Electro & Optical Communications Analysis of Saturation Power Based on Device Structural Parameters of a 1550 nm Symmetrical MQW Semiconductor Optical Amplifier
(Trends in Opto Electro & Optical Communications, STM Journals, 2015-03) Sultana, Nigar; Basak, Rinku
This paper presents the effect of device structure parameters on the saturation power of a1550 nm symmetrical Multi Quantum Well (MQW) Semiconductor Optical Amplifier (SOA)for an amplifier gain of 30 dB. Expressions are given to assess this dependency and the resultsindicate that saturation power decreases with the increase of the number of wells, wellthickness and length but increases with the increase of barrier thickness. Higher number ofwells, relatively large well thickness and length with a barrier thickness closer to the wellthickness should be chosen for all optical switching and wavelength conversion. The findingsof this work can aid SOA design for nonlinear functional devices