Cities worldwide are experiencing rapid urbanization and an increasing population, creating a pressing need for smart infrastructure to enhance citizen services. Dhaka, the capital of Bangladesh, faces similar technological and socio-economic challenges, making it crucial to transform it into a sustainable smart city. This research analyzes the opportunities and challenges of smart cities and Dhaka through SWOT and PESTEL analyses. The study employs a fuzzy rule-based inference system in a MATLAB simulation to calculate the smart city index based on parameters such as governance, transportation, waste management, utility management, healthcare, and industrial automation. The findings reveal that good governance has the highest impact on the smart city index, followed by transportation. The paper proposes a sustainable smart city transportation framework and management technique, outlining future research directions. The proposed framework is expected to impact socio-economic, technological, and environmental aspects positively.

The rapid expansion of the Electric Vehicle (EV) industry is occurring in the world owing to numerous economic and environmental benefits. However, a lack of charging infrastructures could make EV charging quite difficult. Besides, the EV owners recharge the batteries from the residential connection which leads to power quality problems as well as increased system loss. It is known that renewable like solar-based EV charging stations lowers the burden of the utility grid in an eco-friendly way. However, solar irradiation lasts only for few hours a day while EV charging especially in Bangladesh starts from peak hour. Therefore, hybridization of solar with largely available biogas resources in Bangladesh can be a potential solution to overcome the EV charging disputes. To make the EV charging station more effective, reliable, and robust, energy transferring technology like Grid to Vehicle (G2V) and Vehicle to Grid (V2G) in Bangladesh incorporating renewable resources can be implemented. In this paper, V2G and G2V technology for EV charging are proposed using a fuzzy inference system that ensures cost-effective EV charging with lowering peak hour demand. The proposed EVCS offers a real-time charging cost which inspires the EV owners to recharge the batteries during the off-peak hour with the lowest cost.

This paper proposes and experimentally demonstrate sub-bands fusion of photonically generated linear frequency modulated (Ph-LFM) radar signals with unidentical bandwidth and chirp rates using an adaptive, delay-less feed-forward network equalizer (FFNE). We demonstrate this using optical injection in a semiconductor laser to generate Ph-LFM signals at different IEEE X-KA radar sub-bands: 19.25–23.94 GHz and 24.06–28.31 GHz (bandgap 0.12 GHz), 19.69–23.06 GHz and 23.625–27 GHz (bandgap 0.56 GHz), and 8–11.5 GHz and 12.75–17 GHz (bandgap 1.25 GHz). Time-frequency analysis (TFA) was used to obtain sub-bandgap signals of 0.12 GHz, 0.56 GHz, and 1.25 GHz which are coherently fused using the FFNE with a particle swarm optimization (PSO) algorithm to optimize complex-valued weights. The method is evaluated by measuring the range resolution and peak-to-sidelobe level (PSL) in detecting two objects separated by 2 cm and 3 cm. The FFNE achieves significant improvement over 10 dB in PSL and resolves previously unresolvable distances, with maximum range resolutions of 1.8 cm, 2.2 cm, and 2 cm, closely matching theoretical values for full-band LFM signals with bandwidth of 9.06 GHz, 7.31 GHz, and 9 GHz, respectively. Experimental results demonstrate the FFNE’s superior performance in enhancing range resolution and PSL in multi-sub-band radar systems compared to scenarios without FFNE.

In this study, effect of amplified spontaneous emission (ASE) on gain characteristics of bismuth doped fibre (BDF) is investigated at 830 nm pump wavelength. Finding the efficient length of the fibre and suitable pumping conditions are examined. Using BDF up to 15 m of length it is observed that the pump power does not affect the gain much after saturation of gain; but increases both, forward and backward ASE. However, reduced effect of ASE can be found from using a larger pump power. For BDF of 5 m length under 830 nm pump, the gain difference is fluctuated due to the effect of ASE until 120 mW of pump power, and then it jumps up. Besides, in presence of ASE the gain difference moves up until 120 mW of pump power for the BDF length of 10 m and 15 m, and then it moves downward. Hence, it is suitable to use 10 m length of fibre with pump power of 300 mW; the 5 m of fibre length cannot be used because of an upward gain difference due to the effect of ASE with increasing pump power. For all the cases, signal power increases ASE and that hampers the gain to be declined. Lastly, the gain performance of BDF is compared and found much smaller than that of erbium doped fibre (EDF).