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Design of a High-Gain 2 × 1 Array Antenna for S-Band Applications

World Journal of Engineering and Technology 2023年第2期11卷 293-302页

作者： md. Imran Hossain md. Ariful Islam md. tofail ahmed md. Humaun Kabir Department of Electrical Electronic and Communication Engineering Pabna University of Science and Technology Pabna Bangladesh Department of Electrical and Electronic Engineering Pabna University of Science and Technology Pabna Bangladesh Department of Information and Communication Engineering Pabna University of Science and Technology Pabna Bangla-desh Department of Computer Science and Engineering Bangamata Sheikh Fojilatunnesa Mujib Science & Technology University Jamalpur Bangladesh

Antennas are an indispensable element in wireless networks. For long-distance wireless communication, antenna gains need to be very strong (highly directive) because the signal from the antenna loses a lot of strength as it travels over long distances. This is true in the military with missile, radar, and satellite systems, etc. Antenna arrays are commonly employed to focus electromagnetic waves in a certain direction that cannot be achieved perfectly with a single-element antenna. The goal of this study is to design a rectangular microstrip high-gain 2 × 1 array antenna using ADS Momentum. This microstrip patch array design makes use of the RT-DUROID 5880 as a substrate with a dielectric constant of 2.2, substrate height of 1.588 mm, and tangent loss of 0.001. To achieve efficient gain and return loss characteristics for the proposed array antenna, RT-Duroid is a good choice of dielectric material. The designed array antenna is made up of two rectangular patches, which have a resonance frequency of 3.3 GHz. These rectangular patches are excited by microstrip feed lines with 13 mm lengths and 4.8 mm widths. The impedance of the patches is perfectly matched by these transmission lines, which helps to get better antenna characteristics. At a resonance frequency of 3.3 GHz, the suggested antenna array has a directivity of 10.50 dB and a maximum gain of 9.90 dB in the S-band. The S parameters, 3D radiation pattern, directivity, gain, and efficiency of the constructed array antenna are all available in ADS Momentum.

关键词： Microstrip Patch Antenna Array Antenna Microstrip Feed Rectangular Patch Gain Efficiency Directivity ADS

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Prediction of Attention and Short-Term Memory Loss by EEG Workload Estimation

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Journal of Biosciences and Medicines 2023年第4期11卷 304-318页

作者： md. Ariful Islam Ajay Krishno Sarkar md. Imran Hossain md. tofail ahmed A. H. M. Iftekharul Ferdous Department of Electrical and Electronic Engineering Rajshshi University of Engineering and Technology Rajshshi Bangladesh Department of Electrical Electronic and Communication Engineering Pabna University of Science and Technology Pabna Bangladesh Department of Information and Communication Engineering Pabna University of Science and Technology Pabna Bangladesh Department of Electrical and Electronic Engineering Pabna University of Science and Technology Pabna Bangladesh

Mental workload plays a vital role in cognitive impairment. The impairment refers to a person’s difficulty in remembering, receiving new information, learning new things, concentrating, or making decisions that seriously affect everyday life. In this paper, the simultaneous capacity (SIMKAP) experiment-based EEG workload analysis was presented using 45 subjects for multitasking mental workload estimation with subject wise attention loss calculation as well as short term memory loss measurement. Using an open access preprocessed EEG dataset, Discrete wavelet transforms (DWT) was utilized for feature extraction and Minimum redundancy and maximum relevancy (MRMR) technique was used to select most relevance features. Wavelet decomposition technique was also used for decomposing EEG signals into five sub bands. Fourteen statistical features were calculated from each sub band signal to form a 5 × 14 window size. The Neural Network (Narrow) classification algorithm was used to classify dataset for low and high workload conditions and comparison was made using some other machine learning models. The results show the classifier’s accuracy of 86.7%, precision of 84.4%, F1 score of 86.33%, and recall of 88.37% that crosses the state-of-the art methodologies in the literature. This prediction is expected to greatly facilitate the improved way in memory and attention loss impairments assessment.

关键词： Attention Loss Cognitive Impairment EEG Feature Selection SIMKAP Short Term Memory Loss Machine Learning Workload

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Biomass and net primary productivity of mangrove communities along the Oligohaline zone of Sundarbans, Bangladesh

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Forest Ecosystems 2017年第4期4卷 264-272页

作者： md. Kamruzzaman Shamim ahmed Akira Osawa Laboratory of Ecosystem Production and Dynamics Graduate School of Global Environmental Studies Kyoto University Kyoto 606-8501 Japan Forestry and Wood Technology Discipline Khulna University Khulna 9208 Bangladesh

Background： The article presents the first estimates of biomass and productivity for mangrove forests along the Oligohaline zone of the Sundarbans Reserve Forest （SRF）, Bangladesh. This study was conducted overone year from March 2016 to April 20] 7. Stand structure, above and below-ground biomass changes, and litterfall production were measured within a 2100 m2 sample plot. Methods： All trees in the study plots were numbered and height （H） and diameter at breast height （DBH） were measured. Tree height （H） and DBH for each tree were measured in March 2016 and 2017. We apply the above and belowground biomass equation for estimating the biomass of the mangrove tree species （Chave et al. Oecologia 145：87-99, 2005; Komiyama et al. J Trop Ecol 21：471-477, 2005）. Litterfall was collected using 1-mm mesh litter traps with collection area of 0.42 m2. Net Primary Production （NPP） was estimated by the summation method of Ogawa Primary productivity of Japanese forests： productivity of terrestrial communities, JIBP synthesis （1977） and Matsuura and Kajimoto Carbon dynamics of terrestrial ecosystem： Systems approach to global environment （2013）. Results： Heritiero fomes has maintained its dominance of the stand and also suffered the highest tree mortality （2.4%） in the suppressed crown class. The total above-ground biomass （AGB） and below-ground biomass （BGB） of the studied stand was ]54.8 and 84.2 ***-1, respectively. Among the total biomass of the trees, 64.8% was allocated to AGB and 35.2% to BGB. In case of species-wise contribution of biomass allocation, Avicennia officinalis showed the highest score and Aglaia cucullota the lowest. Mean annual total litterfall was 10.1 Mg-ha ***-1, with the maximum litterfall in winter or dry season and late summer or rainy season. The mean AGB increment and above-ground net primary productivity （AGNPP） were 7.1 and 17.2 ***-1, respectively. Total net primary productivity （NPP） was estimated to be 21.0 *** Lyr-1 over the observ

关键词： Primary production Litterfall Monthly pattern Biomass carbon Species wise contribution Sundarbans

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Single polarization photonic crystal fiber filter based on surface plasmon resonance

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Frontiers of Optoelectronics 2019年第2期12卷 157-164页

作者： md. Nazmul HOSSEN md. FERDOUS Kawsar ahmed md. Abdul KHALEK Sujan CHAKMA Bikash Kumar PAUL Department of Information and Communication Technology(ICT) Mawlana Bhashani Science and Technology University(MBSTU)SantoshTangail 1902Bangladesh Group of Biophotomatix SantoshTangail 1902Bagladesh Department of Software Enineering(SWE) Daffodil International UniversityShukrabadDhaka 1207Bangladesh

In this paper,we propose a photonic crystal fiber(PCF)polarization filter based on surface plasmon resonance(SPR)*** nanowire is used as the active plasmonic *** into silica core becomes coupled to gold nanowire stimulating SPR. It soplits light into two orthogonal(x-polarization and y-polarization)polarization in the second order of surface plasmon *** investigations of the proposed PCF filter is finite element method(FEM).By position,the performance of the propsed PCF filter is inspected *** of any polarization can be obtained by properly placing the metal *** maximum cnfinement loss of x-polarization is 692.25dB/cm and y-polarization is 1.13dB/cm offers at resonance position 1.42μ*** a confinement loss difference between two orthogonal polarizations makes PCF a talented candidate to filter ***,the recommended PCF structure is useful for polarization device.

关键词： photonic crystal fiber (PCF) surface plasmon resonance (SPR) perfectly match layer polarization filter

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Design and Optimization of Photonic Crystal Fiber Based Sensor for Gas Condensate and Air Pollution Monitoring

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Photonic Sensors 2017年第3期7卷 234-245页

作者： md. Ibadul ISLAM Kawsar ahmed Shuvo SEN Sawrab CHOWDHURY Bikash Kumar PAUL md. Shadidul ISLAM Mohammad Badrul Alam MIAH Sayed ASADUZZAMAN Department of Information and Communication Technology (ICT) Mawlana Bhashani Science and Technology University Santosh Tangail 1902 Bangladesh Group of Bio-photomatix Tangail 1902 Bangladesh Department of Software Engineering (SWE) Daffodil International University Sukrabad Dhaka 1207 Bangladesh

In this paper, a hexagonal shape photonic crystal fiber （H-PCF） has been proposed as a gas sensor of which both micro-structured core and cladding are organized by circular air cavities. The reported H-PCF has a single layer circular core which is surrounded by a five-layer hexagonal cladding. The overall pretending process of the H-PCF is completed by using a full vectorial finite element method （FEM） with perfectly matched layer （PML） boundary condition. All geometrical parameters like diameters and pitches of both core and cladding regions have fluctuated with an optimized structure. After completing the numerical analysis, it is clearly visualized that the proposed H-PCF exhibits high sensitivity with low confinement loss. The investigated results reveal the relative sensitivity of 56.65% and confinement loss of 2.31×10^-5 dB/m at the 1.33%tm wavelength. Moreover, effective area, nonlinearity, and V-parameter of the suggested PCF are also briefly described.

关键词： Relative sensitivity confinement loss gas sensor effective area nonlinearity and photonic crystal fiber

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Benzene Shape Photonic Crystal Fiber Based Plasma Sensor： Design and Analysis

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Photonic Sensors 2018年第3期8卷 263-269页

作者： md. Toriqul ISLAM md. Golam MOCTADER Kawsar ahmed Sawrab CHOWDHURY Department of Physics Mawlana Bhashani Science and Technology University Santosh Tangail-1902 Bangladesh Group of Bio-photomatix Tangail-1902 Bangladesh Department of Information and Communication Technology Mawlana Bhashani Science and Technology UniversitySantosh Tangail-1902 Bangladesh

A novel benzene core photonic crystal fiber （BC-PCF） is proposed for plasma sensing applications. The proposed BC-PCF parameters have been tuned to gain high sensitivity, high numerical aperture （NA）, and low confinement loss, and modality over the extensive variety of 0.7 μm to 1.9μm wavelength. The explored results for the ideal structure have exhibited the high sensitivity up to 77.84% and negligible confinement loss of 7.9×10^-3dB/m at 1.3μm wavelength. The V-barometer remains under 2.405 over the whole working wavelength. So the proposed BC-PCF is a single mode fiber, which advances the long partition correspondence applications. Furthermore, high numerical aperture （NA） makes the fiber potential candidate in medical imaging applications. The plan of the sensor is to find out the creative potential outcomes in sensing applications.

关键词： Optical sensor relative sensitivity numerical aperture confinement loss benzene core photonic crystal fiber (BC-PCF)

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Design and Optimization of Photonic Crystal Fiber for Liquid Sensing Applications

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Photonic Sensors 2016年第3期6卷 279-288页

作者： md. Faizul Huq ARIF Kawsar ahmed Sayed ASADUZZAMAN md. Abul Kalam AZAD Department of Information and Communication Technology (ICT) Mawlana Bhashani Science and TechnologyUniversity (MBSTU) Tangail-1902 Bangladesh Department of Material and Metallurgical Engineering (MME) Bangladesh University of Engineering and TechnologyUniversity (BUET) Dkaka-l O00 Bangladesh

This paper proposes a hexagonal photonic crystal fiber （H-PCF） structure with high relative sensitivity for liquid sensing; in which both core and cladding are microstructures. Numerical investigation is carried out by employing the full vectorial finite element method （FEM）. The analysis has been done in four stages of the proposed structure. The investigation shows that the proposed structure achieves higher relative sensitivity by increasing the diameter of the innermost ring air holes in the cladding. Moreover, placing a single channel instead of using a group of tiny channels increases the relative sensitivity effectively. Investigating the effects of different parameters, the optimized structure shows significantly higher relative sensitivity with a low confinement loss.

关键词： Photonic crystal fiber (PCF) liquid sensor microstructure core sensitivity confinement loss

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Anisotropic leaky-like perturbation with subwavelength gratings enables zero crosstalk

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Light(Science & Applications) 2023年第6期12卷 1153-1161页

作者： md.Faiyaz Kabir md.Borhan Mia Ishtiaque ahmed Nafiz Jaidye Syed Z.ahmed Sangsik Kim Department of Electrical and Computer Engineering Texas Tech UniversityLubbockTX 79409USA Department of Physics and Astronomy Texas Tech UniversityLubbockTX 79409USA School of Electrical Engineering Korea Advanced Institute of Science and TechnologyDaejeon 34141South Korea

Electromagnetic coupling via an evanescent field or radiative wave is a primary characteristic of light,allowing optical signal/power transfer in a photonic circuit but limiting integration density.A leaky mode,which combines both evanescent field and radiative wave,causes stronger coupling and is thus considered not ideal for dense *** we show that a leaky oscillation with anisotropic perturbation rather can achieve completely zero crosstalk realized by subwavelength grating(SWG)*** oscillating fields in the SWGs enable coupling coefficients in each direction to counteract each other,resulting in completely zero *** experimentally demonstrate such an extraordinarily low coupling between closely spaced identical leaky SWG waveguides,suppressing the crosstalk by≈40 dB compared to conventional strip waveguides,corresponding to≈100 times longer coupling *** leaky-SWG suppresses the crosstalk of transverse–magnetic(TM)mode,which is challenging due to its low confinement,and marks a novel approach in electromagnetic coupling applicable to other spectral regimes and generic devices.

关键词： crosstalk coupling enable

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Recent Progress and Future Trends on the State of Charge Estimation Methods to Improve Battery-storage Efficiency: A Review

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CSEE Journal of Power and Energy Systems 2022年第1期8卷 105-114页

作者： md.Ohirul Qays Yonis Buswig md.Liton Hossain ahmed Abu-Siada Department of Electrical and Electrical Engineering Faculty of EngineeringUniversiti Malaysia SarawakKota SamarahanSarawakMalaysia Department of Electrical and Computer Engineering Curtin UniversityKent StreetBentleyPerth 6102WAAustralia

Battery storage systems are subject to frequent charging/discharging cycles,which reduce the operational life of the battery and reduce system reliability in the long *** such,several Battery Management Systems(BMS)have been developed to maintain system reliability and extend the battery’s operative *** estimation of the battery’s State of Charge(SOC)is a key challenge in the BMS due to its non-linear *** paper presents a comprehensive review on the most recent classifications and mathematical models for SOC *** trends for SOC estimation methods are also presented.

关键词： Battery Management System(BMS) battery modeling battery storage efficiency state of charge(SOC)

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Active Cell Balancing Control Strategy for Parallelly Connected LiFePO_(4) Batteries

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CSEE Journal of Power and Energy Systems 2021年第1期7卷 86-92页

作者： md.Ohirul Qays Yonis Buswig md.Liton Hossain md.Momtazur Rahman ahmed Abu-Siada Department of Electrical and Electrical Engineering Faculty of EngineeringUniversity Malaysia SarawakKota SamarahanSarawakMalaysia Department of Electrical and Computer Engineering Curtin UniversityKent StreetBentleyPerth 6102WAAustralia Electron Science Research Institute Edith Cowan University270 Joondalup DriveJoondalupWA6027Australia

While several recent studies have focused on elimi-nating the imbalance of energy stored in series-connected battery cells,very little attention has been given to balancing the energy stored in parallel-connected battery *** such,this paper aims at presenting a new balancing approach for parallel LiFePO_(4) battery *** this regard,a Backpropagation Neural Network(BPNN)based technique is employed to develop a Battery Management System(BMS)that can assess the charging status of all cells and control its operations through a DC/DC Buck-Boost *** results demonstrate the effectiveness of the proposed approach in balancing the energy stored in parallel-connected battery cells in which the state of charge(SoC)estimation error is found to be only 1.15%.

关键词： Active cell balancing battery management system DC/DC buck-boost converter state of charge estimation

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