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Journal of Advanced Dielectrics 2019年第2期9卷 63-71页

作者： Mohammad Sajjad Hossain Yeasmin Akter Mohammad Shahjahan Muhammad Shahriar Bashar MostHosney Ara Begum MdMoazzem Hossain Suravi Islam Nazia Khatun mdal-mamun Industrial Physics Division BCSIR Laboratories Dhaka BCSIRDhaka-1205Bangladesh Department of Physics University of Chittagong Chottogram-4331Bangladesh Institute of Fuel Research and Development BCSIR Dhaka-1205Bangladesh Bangladesh Atomic Energy Centre BAEC Dhaka-1000Bangladesh

Polycrystalline NiCuZn ferrite(Ni_(x)Cu_(0.3)Zn(0.7-x)Fe_(2)O_(4);x=0.2,0.3,0.4 and 0.5)were prepared through solgel auto combustion method applying double sintering ***,morphological,elemental analyses(EDS),Fourier-transform infrared spectroscopy(FTIR),Direct Current(DC)electrical resistivity,dielectric,magnetic and optical properties of prepared samples were *** profiles reveal the formation of simple cubic spinel structure without any traceable *** average crystallite size lies within the range of 22–29 *** parameter decreases with increasing Ni *** temperature DC resistivity was recorded from 6:39×10^(5)to 3:79×10^(5)Ω*** dielectric constant(ε)and loss factor(tanδ)were decreased with increase of frequency while AC conductivity *** absorption peak occurred at three different frequency ranges at 570-577 cm^(-1),1635-1662 cm^(-1)and 3439–3448 cm^(-1).Magnetic properties were investigated by using vibrating sample magnetometer(VSM).Decreasing trends were observed for saturation magnetization(Ms),magnetic coercivity(Hc)and remanant magnetization(Mr)with the increase of Ni *** band gap(-2.70-2.79 eV)were calculated from diffuse reflectance data by using Kubelka–Munk function.

关键词： Sol-gel NiCuZn ferrite FTIR DC resistivity dielectric optical properties

Influence of waning immunity on vaccination decision-making:A multi-strain epidemic model with an evolutionary approach analyzing cost and efficacy

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Infectious Disease Modelling 2024年第3期9卷 657-672页

作者： Md.mamun-Ur-Rashid Khan Jun Tanimoto Interdisciplinary Graduate School of Engineering Sciences Kyushu UniversityKasuga-koenKasuga-shiFukuoka816-8580Japan Faculty of Engineering Sciences Kyushu UniversityKasuga-koenKasuga-shiFukuoka816-8580Japan Department of Mathematics University of DhakaDhaka1000Bangladesh

In this research,we introduce a comprehensive epidemiological model that accounts for multiple strains of an infectious disease and two distinct vaccination *** stands out as the most effective means to prevent and manage infectious ***,when there are various vaccines available,each with its costs and effectiveness,the decision-making process for individuals becomes ***,the factor of waning immunity following vaccination also plays a significant role in influencing these *** understand how individuals make decisions in the context of multiple strains and waning immunity,we employ a behavioral model,allowing an epidemiological model to be coupled with the dynamics of a decision-making *** base their choice of vaccination on factors such as the total number of infected individuals and the cost-effectiveness of the *** findings indicate that as waning immunity increases,people tend to prioritize vaccines with higher costs and greater ***,when more contagious strains are present,the equilibrium in vaccine adoption is reached more ***,we delve into the social dilemma inherent in our model by quantifying the social efficiency deficit(SED)under various parameter combinations.

关键词： Multistrain epidemic model Vaccination Behavior dynamics Waning immunity Social dilemma

Development of a Lightweight Model for Handwritten Dataset Recognition: Bangladeshi City Names in Bangla Script

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Computers, Materials & Continua 2024年第8期80卷 2633-2656页

作者： MdMahbubur Rahman Tusher Fahmid Al Farid mdal-Hasan Abu Saleh Musa Miah Susmita Roy Rinky Mehedi Hasan Jim Sarina Mansor MdAbdur Rahim Hezerul Abdul Karim Department of Computer Science and Engineering Bangladesh Army University of Science and Technology(BAUST)Saidpur5310Bangladesh Faculty of Engineering Multimedia UniversityCyberjaya63100Malaysia Pabna University of Science and Technology Pabna6600Bangladesh

The context of recognizing handwritten city names,this research addresses the challenges posed by the manual inscription of Bangladeshi city names in the Bangla *** today’s technology-driven era,where precise tools for reading handwritten text are essential,this study focuses on leveraging deep learning to understand the intricacies of Bangla *** existing dearth of dedicated datasets has impeded the progress of Bangla handwritten city name recognition systems,particularly in critical areas such as postal automation and document ***,no prior research has specifically targeted the unique needs of Bangla handwritten city name *** bridge this gap,the study collects real-world images from diverse sources to construct a comprehensive dataset for Bangla Hand Written City name *** emphasis on practical data for system training enhances *** research further conducts a comparative analysis,pitting state-of-the-art(SOTA)deep learning models,including EfficientNetB0,VGG16,ResNet50,DenseNet201,InceptionV3,and Xception,against a custom Convolutional Neural Networks(CNN)model named“Our CNN.”The results showcase the superior performance of“Our CNN,”with a test accuracy of 99.97% and an outstanding F1 score of 99.95%.These metrics underscore its potential for automating city name recognition,particularly in postal *** study concludes by highlighting the significance of meticulous dataset curation and the promising outlook for custom CNN *** encourages future research avenues,including dataset expansion,algorithm refinement,exploration of recurrent neural networks and attention mechanisms,real-world deployment of models,and extension to other regional languages and *** recommendations offer exciting possibilities for advancing the field of handwritten recognition technology and hold practical implications for enhancing global postal services.

关键词： Handwritten recognition Bangladeshi city names Bangla handwritten city name automated postal services

Stock appraisal for Atlantic tripletail(Lobotes surinamensis;Bloch,1790)in the Bay of Bengal,Bangladesh

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Journal of Oceanology and Limnology 2024年第5期42卷 1683-1694页

作者： Suman BARUA Qun LIU Ahmed Fazley RABBY MdAbdullah AL-mamun Xu CHEN Rokeya SULTANA Aidah BALOCH College of Fisheries Ocean University of ChinaQingdao 266003China Department of Fisheries Ministry of Fisheries and LivestockDhaka 1215Bangladesh Bangladesh Fisheries Research Institute Cox’s Bazar 4700Bangladesh Directorate of Secondary and Higher Education Ministry of EducationDhaka 1000Bangladesh Gwadar Development Authority Gwadar 91200Pakistan

The Atlantic tripletail(Lobotes surinamensis)is a high revenue-generating fish species predominantly caught by mechanized artisanal fishers community and the most available member of its family in *** is a ground work of fish stock assessment study in the Bay of Bengal region to explore the life history parameters and associated biomass of this species,using three length-based approaches of TropFishR,the length-based Bayesian biomass estimation(LBB),and Froese’s length based indicators(LBIs).An almost homogenous body growth pattern(b=3.07;R^(2)=0.98)was observed in the length-weight relationship of *** life history parameters for tripletail,as determined by the von Bertalanffy Growth Function(VBGF)model,were L_(∞)=113.36 cm and k=0.51/*** length converted catch curve(LCCC)yielded an estimation of the total mortality(Z=1.77/a),with the natural mortality estimated at(M=0.53/a)and the fishing mortality estimated at(F=1.24/a).But,the ratio of mortality(F/M=0.15)by LBB captured the non-fully exploited status of biomass(B/B_(MSY)=2.1).LBI analysis indicated that the tripletail fishery’s spawning stock biomass is greater than the target and limit reference points,indicating a healthy state of biomass.

关键词： Bay of Bengal Lobotes surinamensis TropFishR length based indicator(LBI) length-based Bayesian biomass estimation(LBB) Bangladesh

Regeneration mechanisms and therapeutic strategies for neuromuscular junctions in aging and diseases

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Neural Regeneration Research 2025年第1期20卷 193-194页

作者： Masashi Fujitani Abu Md mamun Tarif Yoshinori Otani Department of Anatomy and Neuroscience Faculty of MedicineShimane UniversityShimaneJapan

The neuromuscular junction(NMJ)is an essential synaptic structure composed of motor neurons,skeletal muscles,and glial cells that orchestrate the critical process of muscle contraction(Li et al.,2018).The typical NMJ structure is classically described as having a“pretzel-like”shape in mice(Figure 1),whereas human NMJs have a smaller,fragmented structure throughout *** NMJs exhibit smaller or fragmented endplates,partial denervation,reduced numbers of synaptic vesicles,abnormal presynaptic mitochondria,and dysfunctional perisynaptic Schwann cells(Alhindi et al.,2022).

关键词： aging structure Figure

Optimizing Memory Access Efficiency in CUDA Kernel via Data Layout Technique

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Journal of Computer and Communications 2024年第5期12卷 124-139页

作者： Neda Seifi Abdullah Al-mamun Department of Computer & Cyber Sciences— SCCS Augusta University Augusta Georgia USA

Over the past decade, Graphics Processing Units (GPUs) have revolutionized high-performance computing, playing pivotal roles in advancing fields like IoT, autonomous vehicles, and exascale computing. Despite these advancements, efficiently programming GPUs remains a daunting challenge, often relying on trial-and-error optimization methods. This paper introduces an optimization technique for CUDA programs through a novel Data Layout strategy, aimed at restructuring memory data arrangement to significantly enhance data access locality. Focusing on the dynamic programming algorithm for chained matrix multiplication—a critical operation across various domains including artificial intelligence (AI), high-performance computing (HPC), and the Internet of Things (IoT)—this technique facilitates more localized access. We specifically illustrate the importance of efficient matrix multiplication in these areas, underscoring the technique’s broader applicability and its potential to address some of the most pressing computational challenges in GPU-accelerated applications. Our findings reveal a remarkable reduction in memory consumption and a substantial 50% decrease in execution time for CUDA programs utilizing this technique, thereby setting a new benchmark for optimization in GPU computing.

关键词： Data Layout Optimization CUDA Performance Optimization GPU Memory Optimization Dynamic Programming Matrix Multiplication Memory Access Pattern Optimization in CUDA

Interaction between Biochar and Algae on Problem Soil

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Journal of Materials Science and Chemical Engineering 2024年第1期12卷 56-68页

作者： Tazeen Fatima Khan Abdullah Al mamun Nipu Department of Soil Water and Environment University of Dhaka Dhaka Bangladesh Department of Virology International Centre for Diarrhoeal Disease Research Bangladesh (ICDDR B) Dhaka Bangladesh

An in-vitro experiment was conducted to assess the interaction between biochar and algae on a problem soil. Experiments were performed with and without algae to observe the effectiveness of algae for overcoming the challenges posed by problem soils. At the end of incubation periods, the adsorption and desorption of phosphorus (P) on a problem soil vis-á-vis algal inoculation were determined. Our results showed that different types of biochars adsorbed different amounts of P suggesting that the source of biochar played a crucial role in determining its behavior towards P. Tannery waste biochar significantly adsorbed 147% and 35% more P compared to that of the chicken litter and orange peel biochars respectively. Significant reductions in adsorption were observed when the biochar was used in combination with the algae which could be due to the beneficial effects of algae leading to the amelioration of the problem soil. Adsorption was reduced to 34%, 24% and 20% for the orange peel biochar + algae, chicken litter biochar + algae and tannery waste biochar + algae, respectively compared to the corresponding biochars present as a single solid. Phosphorus (P) desorption was also reduced significantly in presence of algal inoculation. Overall our findings suggest that the application of algae along with biochar in the problem soil could reduce the adsorption of P which would influence the availability of P.

关键词： Biochar Algae Problem Soil Interaction Phosphorus

Frequency of Uveitis among Juvenile Idiopathic Arthritis Patients in a Tertiary Care Hospital of Bangladesh: A Retrospective Study

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Open Journal of Rheumatology and Autoimmune Diseases 2024年第3期14卷 144-156页

作者： Md. Asif Ali Mujammel Haque Kamrul Laila Mohammad Hafiz Al-mamun Mohammed Mahbubul Islam Mohammad Imnul Islam Manik Kumar Talukder Pediatric Rheumatology Division Department of Pediatrics Bangabandhu Sheikh Mujib Medical University Dhaka Bangladesh

Background: Juvenile idiopathic arthritis (JIA) is the most frequently encountered pediatric rheumatologic disorder with an unknown etiology. At present there is no published data regarding the frequency of uveitis in patients with JIA in Bangladesh. This study aimed to observe the frequency of JIA-associated uveitis (JIAU) and distribution of uveitis among different sub-categories of JIA at the Pediatric Rheumatology division, both outdoor and indoor patients, Department of Pediatrics, Bangabandhu Sheikh Mujib Medical University (BSMMU) in Bangladesh. Methods: This was a retrospective study of 1784 JIA patients at the Pediatric Rheumatology division, BSMMU from July 2010 to March 2023. Results: Among the 1784 enrolled JIA patients, we observed that 0.73% of cases had uveitis. Here, 61.5% of JIAU cases were male. Most of the cases (92.3%) had bilateral uveitis and only 7.7% cases had unilateral uveitis. Among JIAU patients, the majority were Oligo JIA (53.8%), followed by ERA 30.8%, Poly JIA RF(−) 7.7% and Systemic JIA 7.7% cases respectively. This study also revealed that 15.4% of JIAU patients had ANA positivity and 23% had HLA B-27 positivity. Here we also found ocular complications associated with uveitis such as band keratopathy (23.1%), posterior synechiae (15.4%) and cataract (15.4%). Conclusions: In this study, we observed only 0.73% of patients of JIA had developed uveitis which is lower than the frequency observed in other European studies. This study also showed various ocular complications amongst JIA-associated uveitis patients which signifies the importance of adherence to periodic ophthalmological follow-up to prevent these ocular complications.

关键词： JIA Uveitis HLA-B27 ANA BSMMU

Partially Overlapping Channel Assignment Using Bonded and Non-Bonded Channels in IEEE 802.11n WLAN

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Computers, Materials & Continua 2022年第5期71卷 3161-3178页

作者： MdSelim Al mamun Fatema Akhter Graduate School of Natural Science and Technology Okayama UniversityOkayama700-8530Japan Computer Science and Engineering Jatiya Kabi Kazi Nazrul Islam UniversityMymensingh2224Bangladesh

Nowadays,wireless local area network(WLAN)has become prevalent Internet access due to its low-cost gadgets,flexible coverage and hasslefree simple wireless *** facilitates wireless Internet services to users with mobile devices like smart phones,tablets,and laptops through deployment of multiple access points(APs)in a network *** AP operates on a frequency band called *** wireless standard such as IEEE 802.11n has a limited number of channels where frequency spectrum of adjacent channels overlaps partially with each *** a crowded environment,users may experience poor Internet services due to channel collision i.e.,interference from surrounding APs that affects the performance of the WLAN ***,it becomes a challenge to maintain expected performance in a crowded environment.A mathematical model of throughput considering interferences from surrounding APs can play an important role to set up a WLAN system *** set up,assignment of channels considering interference can maximize network *** this paper,we investigate the signal propagation of APs under interference of partially overlapping channels for both bonded and non-bonded ***,a throughput estimation model is proposed using difference of operating channels and received signal strength indicator(RSSI).Then,a channel assignment algorithm is introduced using proposed throughput estimation ***,the efficiency of the proposal is verified by numerical experiments using *** results show that the proposal selects the best channel combination of bonded and non-bonded channels that maximize the performance.

关键词： Wireless local area network partially overlapping channel throughput estimation model channel assignment algorithm

Nonplanar Shock Excitations in a Four Component Degenerate Quantum Plasma:the Effects of Various Charge States of Heavy Ions

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Plasma Science and Technology 2015年第3期17卷 177-182页

作者： M.R.HOSSEN A.A.mamun Department of Natural Sciences Daffodil International University Department of Physics Jahangirnagar University

A theoretical study on the nonlinear propagation of nonplanar （cylindrical and spherical） electrostatic modified ion-acoustic （mIA） shock structures has been carried out in an unmagnetized, collisionless four component degenerate plasma system （containing degenerate electron fluids, inertial positively as well as negatively charged light ions, and positively charged static heavy ions）. This investigation is valid for both non-relativistic and ultra-relativistic limits. The modified Burgers （mB） equation has been derived by employing the reductive perturbation method, and used to numerically analyze the basic features of shock structures. It has been found that the effects of degenerate pressure and number density of electron and inertial positively as well as negatively charged light ion fluids, and various charging state of positively charged static heavy ions significantly modify the basic features of mIA shock structures. The implications of our results to dense plasmas in astrophysical compact objects （e.g., non-rotating white dwarfs, neutron stars, etc.） are briefly discussed.

关键词： modified ion-acoustic waves shock waves nonplanar geometry relativistic effect degenerate pressure