Browsing by Author "Ahmed, Sabbir"

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An approach to detect epileptic seizure using XAI and machine learning
(BRAC University, 2022-05) Bijoy, Emam Hasan; Rahman, Md. Hasibur; Ahmed, Sabbir; Laskor, Md. Shifat; Hossain, Muhammad Iqbal; Rahman, Rafeed
One of the most common neurological disorder in health sector is Epileptic Seizure (ES) which is occurred by sudden repeated seizures. Hitherto more than 50 million people in the whole world are suffering from Epileptic Seizures. The abnormal brain activity of the central nervous system often causes unusual behavior, losing awareness and psychological problems etc. Moreover, many risks associated with epileptic seizures include sudden unexpected death in epilepsy (SUDEP) which is really a concerning problem discussed in this article. For abstaining from adverse consequences of epileptic seizure-like this health sector focuses more on the early prediction and detection of epilepsy. The complex signals of brain activity are reflected as swift-passing exalted peaks in Electroencephalogram (EEG). Initially, the specialist inspects the EEG signals over a few weeks or months to identify the presence of epileptic seizures, which is a very time-consuming and challenging task. Hence, Machine learning (ML) based classifiers are capable to categorize EEG signals and detect seizures along with displaying related perceptible patterns by maintaining accuracy and efficiency. In order to detect epileptic seizures, EEGbased signal recognition algorithms had been shown in this paper by applying both Multi-Class Classification and Binary classification. The algorithms were Decision Tree Algorithm, Random Forest Algorithm, Multi-Layer Perceptron (MLP) and K-Nearest Neighbor (KNN), Gradient Boosting Classifier, Gaussian Na¨ıve Bayes, Complement Na¨ıve Bayes, SGD Classifier, Explainable Artificial Intelligence (XAI), LIME Algorithm etc. However, K-Nearest Neighbor appears with pretty higher accuracy in certain conditions.
An autonomous rover for efficient waste segregation and collection in urban parks and fields
(BRAC University, 2025-09) Khan, Nafim Karim; Hassan, Farhad; Huq, Rubaya; Khan, Shah Rasul; Bhuian, Mohammed Belal Hossain; Islam, Md. Mahmudul; Ahmed, Sabbir
This project presents the design and implementation of an autonomous rover system for efficient waste segregation and collection in urban parks and fields. Bangladesh faces significant challenges in solid waste management due to rapid urbanization and limited infrastructure which results in environmental and health hazards. To address this, we developed a rover equipped with a Raspberry Pi 5, Pi camera and a 4-DOF robotic arm. A YOLOv8n machine learning model enables real-time waste detection and classification into biodegradable and non-biodegradable categories with over 84% accuracy from practical scenarios. The rover follows a zigzag navigation path where it autonomously detects and picks up the waste which is then deposited into a compartmentalized bin that rotates through a servo. Extensive simulations and tests were conducted which validated its efficiency and achieved complete field coverage within 20 minutes while maintaining sustainable power usage. This solution demonstrates a scalable, cost-effective, and eco-friendly approach to urban waste management which promotes cleaner environments and improved public health.
AN INTERNSHIP REPORT ON “General Banking Activities of Janata Bank Limited” A Study on M.K. Road Corporate Branch, Jessore
(HAJEE MOHAMMOD DANESH SCIENCE AND TECHNOLOGY UNIVERSITY, DINAJPUR, 2011-10) Ahmed, Sabbir; Md. Jamal Uddin
APPLICATION OF SPACE SYNTAX ANALYSIS IN LALBAGH Exploring The Links Between Spatial Analysis And Drug Crime Pattern In Selected Streets Of Lalbagh, Dhaka
(R&D Wing, MIST, 2019-12) Ahmed, Sabbir
Drug crime is an urban problem, and in Lalbagh, its occurrence is fairly common. It can nevertheless be prevented with surveillance, a feature of urban design. Spatial studies and criminology enable us to know significantly about where and why crime occurs. Criminals are rational individuals and they weigh risks and opportunities. A direct correlation can thus be found between the following variables: 1. Risk & Opportunity and 2. Physical Implications of Urban Design which includes spatial attributes. The aim of this paper is to identify the spatial attributes of a major drug crime location (Lalbagh) for helping urban planners, designers and crime control authorities to identify crime zones easily for acting “proactively” rather than “reactively” to the crime. While designing or examining neighbourhoods, for high values of Integration, Integration R=3 and Integration R=10 and Connectivity of an area, we can predict that area to be less crime-prone; because with higher levels of movement, levels of co-presence and co-awareness are expected to be higher. Based on this principle, selected streets of Lalbagh have been studied. Out of the other smaller streets of Lalbagh, Road 10, Shahidnagar was found to be particularly prone to criminal activities and this paper is focused on finding out the reasons behind it, on the basis of space syntax analysis. Depthmap software has been used as a tool to analyze and explain this pattern of drug crime.
AUTOMATIC DAY NIGHT SWITCHING WITH TIMER
(Daffodil International University, 2018-12-01) Reza, Selim; Ahmed, Sabbir
This paper aims at design and executing the advanced development in embedded system for energy saving of lights .Now a days human has become too busy and is unable to find time even to switch the lights where ever not necessary. But the actual timing for these lights to be switched on are when there is absolute darkness. The present system is like the lights will be switched on in the evening before the sun sets and they are switched off the next day morning after there is sufficient light on the outside With this, the power will be wasted up to some extent. This paper gives the best solution for electrical power wastage. Also the manual operation of the lighting system is completely eliminated.
Automatic Day Night Switching with Timer
(Daffodil International University, 2018-12) Reza, Selim; Ahmed, Sabbir
This paper aims at design and executing the advanced development in embedded system for energy saving of lights .Now a days human has become too busy and is unable to find time even to switch the lights where ever not necessary. But the actual timing for these lights to be switched on are when there is absolute darkness. The present system is like the lights will be switched on in the evening before the sun sets and they are switched off the next day morning after there is sufficient light on the outside With this, the power will be wasted up to some extent. This paper gives the best solution for electrical power wastage. Also the manual operation of the lighting system is completely eliminated.
Bangla sign language recognition using leap motion sensor
(BRAC University, 2019-08) Tan, Tamkin Mahmud; Mondol, Anna Mary; Nawal, Noshin; Ahmed, Sabbir; Uddin, Jia
Sign language is used by hearing and speech impaired people to transmit their messages to other people but it is difficult for a regular people to understand this gesture based language. Instantaneous responses on sign language can significantly enhance the understanding of sign language. In this paper, we propose a system that detects Bangla Sign Language using a digital motion sensor called Leap Motion Controller. It is a sensor or device which can detect 3D motion of hands, fingers and finger like objects without any contact. A Sign Language Recognition system has to be designed to recognize a hand gesture. In sign language system, gestures are defined as some specific patterns or movement of the hands to give an expression. There has to be a library which includes all the datasets to match with the user given gestures. We have to compare the sequences of data we get from Leap Motion and our datasets to get an optimal result which is basically the output. It will then show the output as text in the display. For our system, we choose to use $P Point-Cloud Recognizer algorithm to match the input data with our datasets. This recognition algorithm was designed for rapid prototyping of gesture-based UI and can deliver an average over 99% accuracy in user-dependent testing. Our proposed model is designed in a way so that the hearing and speech impaired people can communicate easily and efficiently with common people.
Challenges in 5G Network Planning: Design and Optimization using Atoll
(Department of Electrical and Electronic Engineering, Islamic University of Technology (IUT), Board Bazar, Gazipur-1704, Bangladesh, 2021-03-30) Ahmed, Sabbir; Mahmud, Adib; Hossain, Sheikh Mukaddim
This thesis paper consists of some 5G technology features such as 3D Beamforming, Massive MIMO, mm wave transmission usage [1]. With the introduction to a new period of time the 5G technology of mobile communication helps us to have massive scale communication by connecting innumerable devices giving new alternatives to different sectors which ensures a reliable and services with very low latency to the users. To support all these features, these 5G noteworthy features are acknowledged using a network planning software, Atoll. Atoll is a multi-technology wireless network design and optimization system that guides wireless operators through the entire network design process, from initial planning to densification and optimization. For the design and deployment of 5G networks, it supports the latest technological developments such as massive MIMO, 3D beamforming, and mm - wave propagation. This paper also contains network planning and optimization of a sample area of Uttara using Atoll. The number of base stations required for an optimal communication was observed and set accordingly
Classification of Plant Disease from Leaf Images Using Few-Shot Learning
(Department of Computer Science and Engineering(CSE), Islamic University of Technology(IUT), Board Bazar, Gazipur, Bangladesh, 2022-07-30) Ahmed, Sabbir
To ensure global food security and the overall profit of stakeholders, the importance of correctly detecting and classifying plant diseases is paramount. In this regard, the emergence of Deep Learning-based architectures has provided remarkable performance in plant disease classification in recent times. However, these solutions often require large-scale datasets and high computation resources to learn generalization and achieve state-of-the-art performance. The unavailability of large public datasets in the domain of plant disease classification and low resource constraints of the end-level devices makes the problem even harder. In this regard, we have proposed two solutions to tackle these existing limitations of the Deep Learning-based systems. At first, to ensure the applicability of these solutions in low-end devices we have proposed a lightweight transfer learning-based approach for detecting diseases from tomato leave images. The proposed pipeline utilizes an effective preprocessing method to enhance the leaf images with illumination correction for improved classification. The system extracts features using a combined model consisting of a pretrained MobileNetV2 architecture and a classifier network for effective prediction. Traditional augmentation approaches are replaced by runtime augmentation to avoid data leakage and address the class imbalance issue. Evaluation on tomato leaf images from the PlantVillage dataset shows that the proposed architecture achieves 99.30% accuracy with a model size of 9.60MB and 4.87M floating-point operations, making it a suitable choice for low-end devices. Afterward, to alleviate the dependency on large publicly available datasets, we proposed a pipeline incorporating the concept of Few-shot learning which can predict leaf diseases with only a few samples. The proposed pipeline produces highly general feature embeddings exploiting nine different state-of-the-art CNN-based feature extractors, which are concatenated and passed to a classifier block consisting of a Bi-LSTM layer for effective prediction. We have shown how the concept of `Domain Adaptation' can be utilized in this regard to enhance the representation capability of the feature extractors on unseen classes. The model has been evaluated on the tomato leaf images from the PlantVillage dataset where it achieved promising accuracies of 89.06, 92.46, and 94.07 respectively for 5-shot, 10-shot, and 15-shot classification. Furthermore, an accuracy of 98.09+-0.77 has been achieved 80-shot classification, which is only 1.2% less than state-of-the-art providing 94.5% reduction in the requirement of training data. Experimental findings show that the proposed pipeline has outperformed all the existing works under single-domain, mixed-domain and cross-domain scenarios.
Comparative Study on colorimetric & fastness properties of different dyes on cotton and viscose fabrics
(Daffodil International University, 2019-05-05) Ahmed, Sabbir; Chowdhury, Md. Atikur Rahman
This research presents a comparative study of on colorimetric & fastness properties of 100% Cotton and 100% Viscose knitted fabric dyed with Reactive, Direct, Vat Dyes for 2% shade is reflectance% and carve ware contested and L.a.b.c values and K/S (Color Strength) also measured by using spectral meter color fastness to wash and rubbing test were performed to compare dyeing perform. The results should darker shade on viscose for all dyes than in cotton all most similar wash fastness values were found for reactive and vat dye on both fabric were as direct dye should poor results direct dye should lower (poor) wet rubbing fastness on both fabric then the other two dyes.
COMPARATIVE STUDY ON GROWTH PERFORMANCE OF GREEN MUSSEL (Perna viridis) CULTIVATED ON RAFT AND LONGLINE IN THE COAST OF BAY OF BENGAL
(Chattogram Veterinary and Animal Sciences University Chattogram-4225, Bangladesh, 2021-04) Ahmed, Sabbir
Green mussel (Perna viridis) is one of the most potential mariculture shellfish species not only in context of Bangladesh but also for the world. Developing of P. viridis culture techniques can be a great source of livelihood for many people. A thorough study on the feasible green mussel culture method in the context of Bangladesh is essential for farmers and investors to adapt this new and non-conventional species for commercial aquaculture farming. Therefore, the main purpose of this study was to compare the growth performance of the green mussel cultivated on raft and longline in the coast of Cox’s Bazar, Bangladesh and investigate the relation of growth with the eco-physiological factors of P. viridis. Raft and long-lines were stationed in the coast of Bay of Bengal near Nuniar Chora, Cox’s Bazar for green mussel culture. Water sampling was done twice a month basis for a period of 13 months from November 2019 to November 2020 and P. viridis were sampled from February 2020 to November 2020 after naturally spat settlement. Collected green mussel samples were brought to the laboratory to measure live weight and shell length for analyzing the growth performance. From the study, the maximum live weight and maximum shell length of P. viridis was found 54.56 g and 12.20 cm, respectively which was cultivated in the raft. There was no significant variation in growth of P. viridis cultivated on longline and raft. The growth increment of P. viridis was higher in August than the other months in both raft and longline culture methods. All the water quality parameters of the two culture sites were suitable for green mussel culture and had influence on the growth of green mussel. However, the study will be helpful for local communities to develop green mussel culture near the coast adjacent to their homestead in Nuniar chora, Cox’s Bazar, Bangladesh.
‘Comprehensive Review of Approved Biological Products by The U.S. FDA in 2023
(Daffodil International University, 2024-10-24) Ahmed, Sabbir
The United States Food and Drug Administration (US.FDA) approved numerous innovative pharmaceuticals in 2023. These pharmaceuticals have been subjected to a rigorous evaluation to guarantee their safety and efficacy, and they represent substantial improvements in the treatment of a variety of medical conditions. A diverse array of analytical techniques has been implemented to facilitate their development and subsequent quality control. The analytical methodologies utilized for the evaluation and quality control of FDA-approved drugs are the primary focus of this review. These methodologies comprise a variety of methods that facilitate the characterization, quantification, and quality assessment of pharmaceutical compounds. Frequently implemented chromatographic methods, including highperformance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry, are among the analytical techniques. Spectrometry (LC-MS), UltraPerformance Liquid Chromatography (UPLC), Ultra-high-performance liquid chromatography (UHPLC), and Ultraperformance liquid chromatography-Mass Spectrometry (UPLC-MS). The drugs that have been approved are bexagliflozin (Sodium-glucose cotransporter 2). Daprodustat (Hypoxia-inducible factor prolyl hydroxylase inhibitor), Valmanasealfa-tycv (Recombinant human lysosomal alphamannosidase), Rezafungin (Echinocandin antifungal drug), Sparsentan (Dual endothelin and angiotensin II receptor antagonist), and Nirmatrelvir (Antiviral), Ritonavir (Protease Inhibitors). In general, the FDA's approval of pharmaceuticals in 2023 was contingent upon the implementation of a variety of robust analytical methods. These methods enabled the comprehensive evaluation of drug quality, safety, and efficacy, thereby guaranteeing that patients receive reliable and effective treatment. The development and evaluation of innovative technologies will be further facilitated by the ongoing advancement of analytical techniques pharmaceuticals in the future.
Consumer perception about Western Brands in Bangladesh
(BRAC University, 9/20/2014) Ahmed, Sabbir; Ahmed, Tanvi
Over the years, brand promotional strategies and advertising techniques have changed radically; mostly to cope with the changes in how consumers view and perceive things and to stand out in the clutter of today’s advertising efforts. Marketers and creative agencies are increasingly moving away from the generic advertising methods which mostly included TV and Radio commercials, activations and in case of Bangladesh, a whole lot of billboards. While marketers are realizing the importance of differentiating not only in terms of their product USPs, but also in how they present and promote it to the consumers, it is actually the creative agencies that truly believe in the continual change of the advertising era. However, in a country like Bangladesh, change comes at a glacial pace. Advertising really hasn’t completely moved away or even “far away” from its conventional methods for that matter in our country. Creativity is nurtured and encouraged but very few clients can completely trust their agencies do come up with something ground breaking in their campaigns. Billboards, print ads and TVCs are still used significantly for a campaign whether or not they are required, and this happens mostly in cases where the client is head strong about its decision and doesn’t want to risk not adhering to the traditional mediums of marketing. In a country like Bangladesh, exceptionally innovative ideas in marketing campaigns, especially guerilla advertising that is widely popular abroad, can be rarely implemented because clients feel out of zone and unsure about using them. But this client-agency gap doesn’t stop agencies from trying to come up with newer and more innovative marketing ways and pitching them to the client. Ogilvy Bangladesh has been successful in getting its long term customers to trust in them to provide the best marketing and advertising solutions and stepping outside the box when it came to creative advertising. So I do have a good knowledge about how consumer responses & their tastes about the western brands in Bangladesh. This is a report regarding consumer’s perception of western brands, it will give you a clear view about how consumers build their perceptions on any particular brand or product, how it is affected and the impact of their perception in their purchasing behavior. To prepare this report both primary and secondary sources of data have been used in different aspects. A questionnaire has been made following a particular method which is called projective method and interviewed random general customers to know about their perception. The introductory part is actually developed for the proper implementation of the entire report. The remaining part of the paper actually consist the findings and analysis, managerial contribution and conclusion.
Design and Implementation of a Line Following Robot with Temperature Sensing and Comparing Capability
(East West University, 1/19/2012) Ahmed, Sabbir; Khan, Md. Shlahuddin
Line following robot is a kind of robot which can detect a path drawn in a surface. This can be a black line in white surface or white line in a black surface. In this project we made a line following robot which can follow a white line drawn on a black surface. The robot has another feature - the ability to sense the temperature. So, the objective to make this robot is to follow a white line in black surface and also sense the temperature in its path. The robot is programmed so that it can measure temperature in its path at an interval of 30 seconds. The application of this robot is in temperature sensitive areas like cold storage, chemical industries, medicine manufacturing farms etc. In these areas, maintenance of temperature is an important issue, so we can easily use this robot. The principle of detecting the path uses the reflectivity of light. Black surface absorbs light and white surface reflects it. We have used seven LEDs (Light Emitting Diode) and seven LDRs (Light Depending Resistor) to detect the path. An LED and an LDR together make a single sensor circuit. When the sensor is over a white surface, the light from the LED reflects from the surface to the LDR and due to the decrease of resistivity of the LDR, the voltage across the LDR decreases. The output of each sensor circuit works as an input of a comparator (Ie LM324) which compares the output voltage ofLDR to a reference voltage which is given manually. If the LDR output voltage is higher than the reference voltage, then the comparator outputs logic high; otherwise the comparator output is logic low. So the comparator Ie converts the analog signal to digital. As we have used seven sensors to detect path, so we have a combination of seven bits of logical data. Value of this combination always changes during the path following. We use those combinations to the input pins of the microcontroller as the digital data. In our project we have used microcontroller ATmega16A from AVR. The microcontroller gives output (according to the data and the program code) to a motor drive IC.
Design and implementation of an indoor hydroponic system for enhanced crop production
(BRAC University, 2026) Tuli, Mahabuba Akter; Hasan, Md. Samir; Islam, Md. Sazzadul; Shakib, Sadman; Bhuian, Mohammed Belal Hossain; Islam, Md. Mahmudul; Ahmed, Sabbir
Urban agriculture in densely populated regions, which faces severe constraints due to limited arable land, soil degradation, and water scarcity, requires efficient and space-saving cultivation solutions. This project introduces an automated Indoor Vertical Hydroponic System specifically designed for space-constrained urban environments. By incorporating IoT sensors that monitor TDS, turbidity, water level, temperature, and humidity, the system allows for precise environmental tracking to automate nutrient delivery and optimize crop health. The system operates largely independently of outdoor weather by utilizing spectrum-controlled LED lighting and a camera module for real-time visual monitoring, ensuring year-round production. The use of automated water and oxygen pumps guarantees efficient resource circulation, significantly minimizing water waste compared to traditional soil-based farming. Moreover, the system is designed as a scalable, ready-made agricultural product, providing a user-friendly solution that maximizes yield per square foot. By addressing both space constraints and resource efficiency, this project not only improves the competitiveness of the agricultural sector but also promotes sustainable food security in Bangladesh's land-scarce markets.
Design of Hexagonal Shaped Spectroscopy Based Biosensor for the Detection of Tuberculosis
(Elsevier, 2024-08-30) Hossen, Rakib; Hossain, Md. Selim; Mim, Sadia Afrin; Al-Amin, Md.; Ahmed, Sabbir; Ashrafuzzaman, Md.; Salahin, Md. Ashiq; Sen, Shuvo
A proposal has been made to identify tuberculosis cells using a novel compact sensor based on photonic crystal fiber: PCF in accordance with hexagonal spectroscopy. This proposed structure, which consists of a closely packed hexagonal air hole in the cladding region and a hollow-core area, possesses a very low loss of 6.30 × 10−8 dB/m and an exceptionally high sensitivity of up to 91.75 % (tuberculosis cell for 1.345). Numerous optical parameters have been identified and assessed, comprised of the numerical aperture, the V-parameter, or normalized frequency (Veff), and the effective area (Aeff). The operational wavelength range is defined as 0.80–3.0 THz. The numerical investigation of the properties of the proposed TB sensors is performed within the environment of COMSOL Multiphysics (Version 5.3) using FV-FEM stands for the full vector finite element method. PCF sensors composed of hexagonal lattice in a circular form with ZEONEX as the backdrop material is intended to boost the sensitivity response in comparison to the earlier works. Additionally, the sensor that is being displayed achieves a single modality throughout its whole operational wavelength range. This proposed sensor may play a significant role in identifying tuberculosis thanks to its superior sensitivity response and extremely minimal confinement loss. So, it is clearly seen that this sensor could be used to bio-medical sectors with process of terahertz (THz) wave pulse.
Effective Heart Disease Prediction Using Machine Learning
(Daffodil International University, 2019-05) Hassan, Mahmudul; Alam, Mahmudul; Ahmed, Sabbir
Cardiovascular disease is a leading cause of death in this period. The number of deaths among both males and females increases each day due to heart disease. For example, researchers used machine learning and data mining techniques to support the prognosis of heart disease in healthcare. However, using these techniques there may be a smart system of Heart Disease prediction that is quicker and more proficient than the usual system of diagnosis. The objective of this paper is to use data mining strategies and numerous machine learning algorithms such as Naïve Bayes, Support Vector Machine (SVM), Decision Tree, Logistic Regression, Random Forest, and Various Ensemble Method to gain a more accurate measure. We also suggested two of our own models in this paper. In this paper, a UCI repository Cleveland dataset is used. The sole aim of this paper is to use Data Mining and Machine Learning Techniques to find hidden patterns.
Employee Satisfaction of AKH Group
(Daffodil International University, 2019-04-15) Ahmed, Sabbir
The report is prepared to evaluate the employees’ satisfaction of AKH Group that is entitled “Employee Satisfaction of AKH Group” as a requirement of internship under the BBA program of Daffodil International University. Apart from the academic knowledge gained, preparation of report has given me the opportunity to acquire a practical experience. This report will help to understand the exposure of on the job training in an organization and help to match the theoretical knowledge in a practical situation. The study has been carried out with some objectives such as to explain job satisfaction, to measure the satisfaction, to find out some problems and to make some recommendations for the study. Target population was all the employees of AKH Group from different department who are the part of employees’ job satisfaction in the organization. Sample size of the study is 30 Simple Random Sampling technique was used as a matter of collecting data from the target population for the purpose of conducting the study. Questionnaire and observation method have been used to conduct the study. In questionnaire multiple choice question and open-ended question was used to collect the data. There was a questionnaire with four-Likert scale used to collect the information for this report. Many problems have been identified by the study such as lack of supervision, less benefits and less opportunities, work hour problems, lack of responsible, biasness in the organization. And related to these problems some recommendations are also given in the study. So that they can overcome from those problems. In conclusion, I can say that, every department of AKH Group gives me a pleasure to learn the employee satisfaction properly. From this organization, I have learned practical knowledge about employee satisfaction on the basis of my research I can say that employee attitudes typically reflect the moral of the company. Satisfied employees are extremely important because they represent the company to the public.
Energy efficient human hauler with enhanced safety for urban mobility
(BRAC University, 2026-01) Shahria, MD; Hossain, Sabab; Saiyed, MD Takrim; Ahsan, MD Fardin; Bhuian, Mohammed Belal Hossain; Islam, Md. Mahmudul; Ahmed, Sabbir
Electric rickshaws play a vital role in urban transportation in Bangladesh, but their growing use has increased pressure on the national power grid and raised concerns about energy efficiency and sustainability. This project presents the design and implementation of a hybrid electric rickshaw system that combines human pedaling with controlled motor assistance, solar energy harvesting, and regenerative braking. The Pedal Assist Sensor (PAS) to sense the level of peddling is attached, and an Arduino-based motor controller assists with a maximum of 80 percent of the effort of the rider with a safe maximum speed. The use of solar panels and a regenerative system allows one to recharge a battery during work and become less dependent on grid electricity. The mathematical modeling, simulation, and hardware testing prove that the proposed system reduces battery usage, increases the driving range, and has more energy efficiency. The implemented model is cheap, safe and can be used in the real world, hence is a viable solution to the transportation problem in urban Bangladesh.
Evaluation of THz wave transmission performance in TOPAS-based heptagonal photonic crystal fiber (He-PCF)
(2024-02-15) Hossain, Md Selim; Hossen, Rakib; Al-Amin, Md; Ahmed, Sabbir; Sen, Shuvo
PCF denotes photonic crystal fiber which is utilized for terahertz (THz) waveguides and cladding in the shape of a hexagon with two elliptical air apertures (AHs), which are discussed. Such differentiation is made: When the frequency is 1 THz, effective material loss (EML) to a minimum of 0.028 cm−1 has been achieved. Making use of the heptagonal photonic crystal fiber (He-PCF) architecture, every simulation result utilizing COMSOL Multiphysics software implements the perfectly match layer (PML) and finite element method (FEM) boundary conditions. The He-PCF fiber demonstrates an effective mode loss (EML) of 0.028 cm−1 that is negligible, a substantial effective area (EA) measuring 7.31 × 10−8 m2 and an 80 % power concentration encompassing the central area at 1 THz frequency. Furthermore, regarding crucial optical guiding aspects like confinement loss, dispersion, and modality, a small study with respect to power fraction along with effective mode area (EMA) has again been conducted. Here, He-PCF THz waveguide is anticipated to provide a notable improvement in the current design for the communication field. Moreover, our suggested the PCF demonstrates perception by a solitary mode, as indicated through the utilization of the V-parameter, across a range in frequency spanning among 0.80 and 3 THz. Thus, it is anticipated that the layout of He-PCF fibers will facilitate efficient transmission of terahertz (THz) signals in a variety of communication applications.