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Smart Semi-active PID-ACO control strategy for tower vibration reduction in Wind Turbines with MR damper

Earthquake Engineering and Engineering Vibration 2019年第4期18卷 887-902页

作者： mahmudur rahman Zhi Chao Ong Wen Tong Chong Sabariah Julai Department of Mechanical Engineering Faculty of Engineering University of Malaya

Wind turbine technology is well known around the globe as an eco-friendly and eff ective renewable power source. However, this technology often faces reliability problems due to structural vibration. This study proposes a smart semi-active vibration control system using Magnetorheological (MR) dampers where feedback controllers are optimized with nature-inspired algorithms. Proportional integral derivative (PID) and Proportional integral (PI) controllers are designed to achieve the optimal desired force and current input for MR the damper. PID control parameters are optimized using an Ant colony optimization (ACO) algorithm. The eff ectiveness of the ACO algorithm is validated by comparing its performance with Ziegler-Nichols (Z-N) and particle swarm optimization (PSO). The placement of the MR damper on the tower is also investigated to ensure structural balance and optimal desired force from the MR damper. The simulation results show that the proposed semi-active PID-ACO control strategy can signifi cantly reduce vibration on the wind turbine tower under diff erent frequencies (i.e., 67%, 73%, 79% and 34.4% at 2 Hz, 3 Hz, 4.6 Hz and 6 Hz, respectively) and amplitudes (i.e. 50%, 58% and 67% for 50 N, 80 N, and 100 N, respectively). In this study, the simulation model is validated with an experimental study in terms of natural frequency, mode shape and uncontrolled response at the 1st mode. The proposed PID-ACO control strategy and optimal MR damper position is also implemented on a lab-scaled wind turbine tower model. The results show that the vibration reduction rate is 66% and 73% in the experimental and simulation study, respectively, at the 1st mode.

关键词： ant colony optimization fi nite diff erence method magnetorheological damper PID-ACO controller semiactive control system identifi cation wind turbine tower

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Influence of soil physicochemical properties,particle size fractions and mineralogy on the leaching potentials of arsenic and antimony in abandoned mine soils

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Pedosphere 2023年第5期33卷 744-753页

作者： A.S.M.Fazle BARI Dane LAMB Geoff R.MACFARLANE Mohammad mahmudur rahman Global Centre for Environmental Remediation(GCER) College of EngineeringScience and EnvironmentThe University of NewcastleCallaghanNSW 2308Australia Department of Soil Science Sher-e-Bangla Agricultural UniversityDhaka 1207Bangladesh Chemical and Environmental Engineering School of EngineeringRMIT UniversityMelbourneVictoria 3000Australia School of Environmental and Life Sciences The University of NewcastleCallaghanNSW 2308Australia

At abandoned mine sites,arsenic(As)-and antimony(Sb)-enriched soils are often disposed of through onsite burial or *** highly weathered mine sites,the mobility of As and Sb is typically controlled by iron(Fe)(III)/Fe(II)phases;thus,the suitability of such disposal methods and appropriate testing techniques are *** the present study,leaching potentials of As and Sb were examined using the toxicity characteristic leaching procedure(TCLP),waste extraction test(WET),and WET-extended procedure(WET-EXT)at three abandoned mine site soils in *** leached concentration of As regularly exceeded USEPA criteria(5 mg L^(-1)).The highest leached concentrations of As and Sb were observed in the finest particle size fraction(<0.053 mm)by WET-EXT(1040 mg L^(-1)for As and 21.10 mg L^(-1)for Sb)followed by WET(800 mg L^(-1)for As and 20.90 mg L^(-1)for Sb).The TCLP method resulted in the lowest concentrations of leached As(0.0009 mg L^(-1))and Sb(0.0003 mg L^(-1)).Crystalline and amorphous As-bearing Fe oxides were the main phases in the soils ***,the best correlations of leached As determined by TCLP(0.832),WET(0.944),and WET-EXT(0.961)were found with the non-specifically sorbed(NS1)As *** mineralogical and sequential extraction data clearly indicate the dominant role of Fe geochemistry in controlling leachability of As and *** TCLP method was unlikely to be suitable for assessing leachability,as it exhibited no relationship with leachable Fe and substantially lower leached As and Sb than the other two *** the high to extremely high leachable As and Sb concentrations,most of the soil samples would not be recommended for placement in capping works,old shafts,or reduction systems(e.g.,collection in drainage basins).

关键词： particle size fraction sequential extraction toxic element toxicity characteristic leaching procedure waste extraction test

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Turning Trash into Treasure: Developing an Intelligent Bin for Plastic Bottle Recycling

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Journal of Social Computing 2024年第1期5卷 1-14页

作者： Sirajam Munira Niloy Paul Md Ashraful Alam Md.mahmudur rahman M.Shamim Kaiser Institute of Information Technology Jahangirnagar UniversityDhaka 1342Bangladesh

Plastic pollution has emerged as a major global concern due to its enduring nature and limited recycling *** response to this critical challenge,this paper presents a novel approach utilizing a Detection-Based Reward System(DBRS)alongside an innovative business model to promote effective plastic waste management,reduce plastic waste accumulation in the nature,and uphold environmental *** the YOLOv5 algorithm for its exceptional accuracy,speed,and open-source availability,plastic bottle detection becomes a pivotal aspect of this *** seamlessly enroll in the system,triggering an automated detection process that computes reward points corresponding to their deposited plastic *** reward points are meticulously stored within a centralized *** its operational facets,this comprehensive system encompasses a robust business model,strategically poised to capture widespread engagement with waste disposal practices,thereby contributing to the realization of Sustainable Development Goals(SDGs)geared towards fostering a healthier ***,the DBRS attains cutting-edge performance in plastic bottle detection,boasting an impressive mean Average Precision(mAP)of 0.973,underscoring its efficacy in tackling plastic pollution.

关键词： smart environment reward system YOLOv5 deep learning business model

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Introduction of Zika virus in Bangladesh:An impending public health threat

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Asian Pacific Journal of Tropical Medicine 2017年第9期10卷 925-928页

作者： A.K.M.Muraduzzaman Sharmin Sultana Tahmina Shirin Selina Khatun MdTarikul Islam mahmudur rahman Department of Virology Institute of EpidemiologyDisease Control&Research(IEDCR)DhakaBangladesh Department of Epidemiology Institute of EpidemiologyDisease Control&Research(IEDCR)DhakaBangladesh Laboratory of Genetics and Genomics Institute for Developing Science and Health InitiativesDhakaBangladesh Institute of Epidemiology Disease Control&Research(IEDCR)DhakaBangladesh

Objective: To explore the presence of Zika virus(ZIKV) in Bangladesh and to understand the associated risk ***: A retrospective sero-surveillance was performed on stored serum samples of dengue surveillance conducted from 2013 to 2016. Real time RT-PCR was performed on randomly selected acute serum samples to detect the Zika virus nucleic ***: Of 200 samples screened, one was found positive for ZIKV by real time RTPCR and further confirmed by genome sequencing. The case was a 65 years old male from a metropolitan city of Bangladesh who had no history of travel outside *** analysis of partial E gene sequences from Bangladeshi isolates demonstrated a close relationship with ZIKV from Brazil and current South American strains clustering within a monophyletic clade distinct from African ***: Presence of ZIKV raises serious public health concerns in Bangladesh owing to its association with congenital anomalies/neurological-manifestations. We,therefore, recommend every suspected viral fever patient, particularly pregnant women be screened for ZIKV infection to rule out yet another emerging infection in Bangladesh.

关键词： Zika virus Bangladesh Public health impact

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Effect of the antenna slot numbers and position on the performance of microwave ablation

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Medicine in Novel Technology and Devices 2023年第4期20卷 105-113页

作者： Sabiha Binte Aziz Md Rejvi Kaysir Md Jahirul Islam Torikul Islam mahmudur rahman Department of Biomedical Engineering(BME) Khulna University of Engineering&TechnologyKhulna-9230Bangladesh Photonics Research Group Department of EEEKhulna University of Engineering&TechnologyKhulna-9230Bangladesh Department of Electrical and Computer Engineering Waterloo Institute for NanotechnologyUniversity of Waterloo200 University AveWaterlooONCanada Department of Biomedical Engineering(BME) New Jersey Institute of TechnologyNewarkNJUSA Department of Electrical and Electronic Engineering Dhaka University of Engineering&TechnologyGazipur 1707Bangladesh

Microwave ablation(MWA)is a type of thermal ablation used for cancer treatment in interventional *** induce localized tissue heating MWA employs electromagnetic waves within the microwave energy spectrum,which is done by the precisely designed *** study substantially emphasizes the design and performance ameliorating of slot(both single and double)antennae and compares the results with conventional monopole antennae in terms of temperature distribution,specific absorption ratio(SAR),and thermal tissue damage *** simulation has been done in COMSOL by solving the Bioheat equation along with Maxwell electromagnetic equations using the finite element *** simulation results reveal that the double-slot antenna has the most accurate and directional heat dissipation for liver tumors as well as the highest tissue damage rate and *** highest SAR was found to be 3500 W/kg and 3350 W/kg at the implant depth of 61 mm and 63 mm for double and single-slot antennae,*** addition,the fastest tissue damage occurred near the upper slot of the double-slot *** study helps to understand the basic design parameters for enhancing single and doubleslot antennae performance.

关键词： Microwave ablation(MWA) Finite element method(FEM) Liver tumor Microwave antenna Specific absorption rate(SAR)

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磁流变阻尼器最新进展综述:优化设计和应用（英文）

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2017年第12期18卷 991-1010页

作者： mahmudur rahman Zhi Chao ONG Sabariah JULAI Md Meftahul FERDAUS Raju AHAMED Department of Mechanical Engineering Faculty of Engineering University of Malaya Department of Mechatronics Engineering Faculty of Engineering International Islamic University Malaysia

本文对各种磁流变阻尼器的优化设计、制造和智能应用以及自供电和自感应技术的最新进展进行了综述。本文讨论了磁流变阻尼器的基本设计和结构以及各种类型的配置,以了解它们在各种环境和目的下的多功能性。为了应对不同的应用,本文介绍... 详细信息

本文对各种磁流变阻尼器的优化设计、制造和智能应用以及自供电和自感应技术的最新进展进行了综述。本文讨论了磁流变阻尼器的基本设计和结构以及各种类型的配置,以了解它们在各种环境和目的下的多功能性。为了应对不同的应用,本文介绍了设计的修改、优化和改进。节能是当前的终极需求,是对现代技术的挑战。磁流变阻尼器需要改进,以确保较低的电流供应得到较高的效力。这项工作将有助于在各种结构中使用磁流变阻尼器,使其以最小的电流供应进行振动控制,并在优化中获得最佳结果。

关键词：磁流变阻尼器自供电振动控制节能优化和提升

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Water Based Nanofluids: A Computational Study on Temperature Distribution in a Pipe Flow

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Advances in Nanoparticles 2017年第4期6卷 141-147页

作者： Md. Ebrahim Khalil Bhuiyan Mohammad mahmudur rahman Khan Iqbal Mahmud Department of Textile Engineering Bangladesh University of Business and Technology Dhaka Bangladesh

Fluid containing nanometer-sized particles (i.e. nanoparticles) is known as nanofluid. Three different nanofluids flowing in a pipe with heat source at the inlet and sink in the walls are studied. The base fluid is water. 20 nm size nanoparticle Al2O3 is mixed with base fluid with volume concentrations of 0.1%, 0.2% and 0.5%. Simulation is done using ANSYS Workbench 17.1. The result shows correlation between concentration of nanoparticle and temperature gradient at the outlet of the pipe.

关键词： Nanofluid Nanoparticle Al2O3 CFD ANSYS

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A Critical Analysis of Machine Learning and Deep Learning Methods for Cervical Cancer Screening

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Journal of Computer and Communications 2023年第12期11卷 64-85页

作者： Muhtasim mahmudur rahman Jakir Khan Abu Sale Mohammad Mostafizur rahman Redoanul Haque Md. Sumon Ali Department of Computer Science and Engineering Bangladesh Army University of Engineering & Technology Natore Bangladesh

Cervical cancer is a serious public health issue worldwide, and early identification is crucial for better patient outcomes. Recent study has investigated how ML and DL approaches may be used to increase the accuracy of vagina tests. In this piece, we conducted a thorough review of 50 research studies that applied these techniques. Our investigation compared the outcomes to well-known screening techniques and concentrated on the datasets used and performance measurements reported. According to the research, convolutional neural networks and other deep learning approaches have potential for lowering false positives and boosting screening precision. Although several research used small sample sizes or constrained datasets, this raises questions about how applicable the findings are. This paper discusses the advantages and disadvantages of the articles that were chosen, as well as prospective topics for future research, to further the application of ml and dl in cervical cancer screening. The development of cervical cancer screening technologies that are more precise, accessible, and can lead to better public health outcomes is significantly affected by these findings.

关键词： Cervical Cancer Neoplasms Screening Machine Learning Techniques Deep Learning Techniques

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Influence of Lycra Content and Stitch Length on the Dimensional and Physical Characteristics of Lycra Back Plaited Cotton (LBPC) Single Jersey Fabrics

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Journal of Textile Science and Technology 2022年第4期8卷 203-220页

作者： Md. Razib Sheikh Md. Kawsar Hossain Mohammad mahmudur rahman Khan Department of Textile Engineering Bangladesh University of Business and Technology Dhaka Bangladesh Department of Textile Engineering Khulna University of Engineering and Technology Khulna Bangladesh

The physical and dimensional characteristics, i.e. course and wale spacing, stitch density, tightness factor, diameter, porosity, dimensional stability and bursting strength of single jersey knitted items containing lycra yarn with the variations in stitch length and lycra content have been examined and a detail investigation on the lycra filament has been discussed in this study. Six different samples were knitted with identical cotton and lycra yarn but different in lycra contents and stitch length. After conditioning in a controlled environment, all the samples were tested as per the established methods. After analyzing the test results, noticeable effects of variations in stitch length and lycra content on physical and dimensional characteristics of single jersey knitted fabric has been found. As smaller the stitch length and as greater the lycra content, the dimensional stability and bursting strength are better;on the other hand, the air permeability is lower.

关键词： Lycra Content Stitch Length Back Plaited Dimensional Stability Porosity Bursting Strength

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Exploring the practice of common oral diseases among the patients visiting in the selected dental college and hospital in Bangladesh

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Life Research 2022年第4期5卷 1-5页

作者： Khalid Hasan Pasha Md.Fazlul Karim Md.mahmudur rahman Ashek Elahi Noor Md.Mamunur Rashid Nahid Al Nomann Kazi Golam Mohiuddin Department of Oral&Maxillofacial Surgery Sapporo Dental College and HospitalDhaka-1230Bangladesh Department of Microbiology Kumudini Women’s Medical CollegeMirzapurTangail-1900Bangladesh Department of Gastroenterology Dhaka Medical College and HospitalDhaka-1312Bangladesh Department of Dental Public Health Sapporo Dental College and HospitalDhaka-1230Bangladesh New Labaid Diagnostic Center&Hospital Brahmanbaria-3400Bangladesh Department of Science of Dental Materials Sapporo Dental College and HospitalDhaka-1230Bangladesh

Background:Having the ability to identify potential health risk factors such as lifestyle,ethnicity,health status,and social determinants associated with oral health status risk,health care providers can take an active role in health screening to discover any need for clinical preventive services,including dental preventive services,and can detect health ***:A descriptive type of cross-sectional study was conducted to explore the practice of common oral diseases among the patients visiting in the selected dental college and hospital in Bangladesh from October 2019 to December *** 100 patients were interviewed through a semi-structured questionnaire,followed by an oral examination through a checklist and a face-to-face interview.A systematically random sampling technique was employed to select the study ***:Among them,the(21-30)year age group shows a maximum 20%,whereas the(71-80)year age group represents the minority with only 2%.Among them,56%were male and 44%were *** represent the majority of 26%,whereas others(day laborers)represent only 4%.Decayed teeth remained in 72%of cases,teeth were missing in 31%of cases,and filled teeth were present in 24%of cases.A majority of 71%clean teeth once daily,whereas only 29%clean teeth twice ***,only 30%brush teeth at night and a maximum of 95%brush teeth in the ***,a maximum of 68%use toothpaste and brushes,while only 4%use meswak for cleaning their *** 4%of cases with no debris,51%of cases with less than 1/3rd of the tooth with debris,32%of cases with 1/3rd-2/3rd of the tooth with debris,and 13%of cases with more than 2/3rd of the tooth with debris were ***,about 30%had no calculus,52%less than 1/3rd of tooth,16%in between 1/3rd and 2/3rd of tooth,and 2%more than 2/3rd of the calculus was *** 47%of mild,22%of moderate,6%of severe and 25%had no ***,for treatment purposes,20.69%was advised for scaling,19.66%for

关键词： dental caries abscess broken down root broken down crown decayed missing filled tooth root canal treatment orthopentomogram intra oral periapical cone beam computed tomography body mass index

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