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Financial management for custom hire service of tractor in Bangladesh

International Journal of Agricultural and Biological Engineering 2013年第3期6卷 28-33页

作者： Anisur rahman Most.Latifunnahar md Monjurul Alam Department of Farm Power and Machinery Bangladesh Agricultural UniversityMymensingh-2202Bangladesh

The main purpose of the study was to determine the economic parameters and effective schedules for tractor *** data from various sources were used in this *** essential data were collected from primary sources through *** costs were calculated and project financial profitability was determined by four major factors on farm financial measurement techniques,namely,benefit-cost ratio(BCR),net present value(NPV),internal rate of return(IRR),and payback *** the economic use,land topography and cropping pattern was developed to effective scheduling for tractor *** operating cost of tractor with implement was found to be US$9.25 per *** replacement of the existing tractor on expiry of economic life,the entrepreneur has to save an amount of US$219 per year in a bank *** on the operating cost,annual savings for replacement and a profit margin for the entrepreneur,the rent-out charge of the tractor is estimated at US$11.58 per *** 10%interest rate,the NPV of the tractor at existing condition is US$*** NPV of tractor indicates that tractor entrepreneurship is considered financially sound and the project is financially viable,with an average IRR of 36.96%.This is because IRR of the tractor was higher than the bank interest rate and it is highly profitable from the viewpoint of individual *** Payback period of tractor with implement was determined as 2.03 *** minimum tenure for an economic use of a common tractor used in agriculture is about 6310 *** this critical use,the utilization of a tractor is economical for a tractor *** on the cropping pattern two major and one minor turn-around periods are available in between cropping seasons for tilling *** time available for tilling of land is estimated about 140 days at 12 hours a day in a *** strengthen the existing capacity of the tractor customer hire service entrepreneurs an

关键词： tractor operating cost economic parameter effective scheduling tractor entrepreneur Bangladesh

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Landslide initiation and runout susceptibility modeling in the context of hill cutting and rapid urbanization: a combined approach of weights of evidence and spatial multicriteria

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Journal of Mountain Science 2017年第10期14卷 1919-1937页

作者： rahman md.Shahinoor AHMED Bayes DI Liping Center for Spatial Information Science and Systems George Mason University BUET-Japan Institute of Disaster Prevention and Urban Safety Bangladesh University of Engineering and Technology (BUET) Institute for Risk and Disaster Reduction Department of Earth SciencesUniversity College London (UCL) Department of Disaster Science and Management Faculty of Earth and Environmental SciencesUniversity of Dhaka

Rainfall induced landslides are a common threat to the communities living on dangerous hillslopes in Chittagong Metropolitan Area, Bangladesh. Extreme population pressure, indiscriminate hill cutting, increased precipitation events due to global warming and associated unplanned urbanization in the hills are exaggerating landslide events. The aim of this article is to prepare a scientifically accurate landslide susceptibility map by combining landslide initiation and runout maps. Land cover, slope, soil permeability, surface geology, precipitation, aspect, and distance to hill cut, road cut, drainage and stream network factor maps were selected by conditional independence test. The locations of 56 landslides were collected by field surveying. A weight of evidence(Wo E) method was applied to calculate the positive(presence of landslides) and negative(absence of landslides) factor weights. A combination of analytical hierarchical process(AHP) and fuzzymembership standardization(weighs from 0 to 1) was applied for performing a spatial multi-criteria evaluation. Expert opinion guided the decision rule for AHP. The Flow-R tool that allows modeling landslide runout from the initiation sources was applied. The flow direction was calculated using the modified Holmgren's algorithm. The AHP landslide initiation and runout susceptibility maps were used to prepare a combined landslide susceptibility map. The relative operating characteristic curve was used for model validation purpose. The accuracy of Wo E, AHP, and combined susceptibility map was calculated 96%, 97%, and 98%, respectively.

关键词：山体滑坡快速城市化证据权重法因子权重模型验证敏感性行空间联合方法

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Investigation on the Ballistic Performance of Para-Aramid Fabric under Effects of Varied Inter-Yarn Friction,Woven Architecture,and Layer

Investigation on the Ballistic Performance of Para-Aramid Fa...

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作者： md Riazur rahman 中原工学院

学位级别：硕士

弹道冲击是一个非常复杂的力学过程,主要取决于目标材料的不同设计、厚度、强度、密度和弹丸参数。由于高强力、高模量纤维的发展,大量纺织织物用于防弹衣设计。本研究主要目的是分析不同织物结构、层数及纱线间摩擦力的织物靶板的防弹... 详细信息

弹道冲击是一个非常复杂的力学过程,主要取决于目标材料的不同设计、厚度、强度、密度和弹丸参数。由于高强力、高模量纤维的发展,大量纺织织物用于防弹衣设计。本研究主要目的是分析不同织物结构、层数及纱线间摩擦力的织物靶板的防弹性能。使用有限元模拟评估机织物在圆柱形弹丸以475 m/s的冲击速度下的防弹性能。该模型中织物设为边长为7.54 cm的正方形,采用四边夹紧的边界条件。层数变化为1、4、8和12层,纱线间摩擦力由静摩擦系数和动摩擦系数表示,设置了三个级别的纱线间摩擦力,考虑了五种织物结构包括平纹、五枚缎纹、八枚缎纹、十一枚缎纹和UD织物。主要从这些防弹织物靶板弹道冲击中的能量吸收、背面变形和失效机理等进行了分析。首先,研究了1层、4层、8层和12层的UD织物、平纹织物和五枚缎纹织物的防弹性能。随着纱线间摩擦力的增加,三种多层织物的总能量吸收、动能和应变能都增加,尤其是在多层条件下;而摩擦耗散能仅在纱线间摩擦力水平居中时达到峰值。织物结构对整体能量吸收的影响表现出这样一种趋势:当层数和纱线间摩擦都较大时,五枚缎纹织物成为能量吸收的最佳结构。通过应力分布分析,所有靶板都显示出在较低的纱线间摩擦力下,各层更容易断裂,而在相同的时刻,在较高纱线间摩擦力下各层仍然完好无损,且承担更多应力。此外,与其他两个织物结构靶板相比,多层缎纹织物靶板中剩余层中的应力分布更加均匀。由于缎纹结构是最好的吸能结构,在上述研究基础上,接着对比分析了五枚、八枚和十一枚不同浮长线的缎纹织物在纱线间摩擦力和层数下的弹道冲击性能。随着纱线间摩擦力的增加,三种不同层数和浮长缎纹织物的能量吸收都显著增加。对于浮长线的影响,由于较长的浮长线会使织物结构更松散,因此浮长较大的织物靶板变形较大。对于缎纹织物作为防弹层而言,浮长线并不是长度越长,其防弹性能越好。最后,从主、次纱线的作用、各层在多层体系中的作用、剪切应力和拉伸应力的传播等方面详细分析了五枚缎纹织物的弹道能量吸收机理和破坏机理。对于五枚缎纹织物,发现主纱线在冲击初期吸收更多的动能和应变能,而次生纱线在冲击后期吸收更多的动能和应变能。此外,纱线间摩擦力的增加会增强主次纱线的作用,使其吸收更多的能量。对于多层五枚缎纹织物靶板,随着纱线间摩擦的增加,系统中每层织物吸收的应变能和动能都会增大。然而,纱线间摩擦力增加也带了不利的影响,即虽加强前层织物的能量吸收性能,但削弱后层能量吸收性能。对于主纱线的断裂,在较高纱线间摩擦力下,前层的主纱线承受较大的拉应力和剪应力,而后层的纱线承受较小的拉应力和剪应力。

关键词：织物靶板弹道冲击能量吸收背面变形失效机理防弹性能

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大麦HvGBSSI基因剪接受体位点的突变影响RNA剪接，降低直链淀粉含量

大麦HvGBSSI基因剪接受体位点的突变影响RNA剪接，降低直链淀粉含...

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作者： md Mostafijur rahman 四川农业大学

学位级别：硕士

大麦(Hordeum vulgare L.)籽粒是复合碳水化合物的重要来源,淀粉约占大麦籽粒重量的60%～75%。颗粒结合淀粉合酶I(Hv GBSSI)由大麦Wx-1基因编码,GBSSI是大麦中催化直链淀粉合成的唯一酶。Hv GBSSIa在胚乳中表达,Hv GBSSIb在种皮和胚中... 详细信息

大麦(Hordeum vulgare L.)籽粒是复合碳水化合物的重要来源,淀粉约占大麦籽粒重量的60%～75%。颗粒结合淀粉合酶I(Hv GBSSI)由大麦Wx-1基因编码,GBSSI是大麦中催化直链淀粉合成的唯一酶。Hv GBSSIa在胚乳中表达,Hv GBSSIb在种皮和胚中表达。甲磺酸乙酯(EMS)是一种常用的诱导突变的化学物质,已广泛用于玉米、水稻和小麦等作物的化学诱变。EMS导致的突变品系可以直接用于育种,没有任何基因修饰争议。本研究从甲基磺酸乙酯(EMS)诱变大麦群体中鉴定出一个Wx-1突变体,命名为M2-1105。突变体M2-1105的Wx-1基因在第四个内含子剪接受体位点发生碱基突变,导致直链淀粉含量降低。突变体M2-1105中Wx-1基因有两个单碱基突变G1086A和A2424G。G1086A突变位于第4内含子的3’剪接受体(AG)位点,导致RNA剪接异常。A2424G突变是第九个内含子的同义突变。由于G1086A位于剪接受体位点,导致Wx-1的前体m RNA被错误剪接,转录成了两个异常转录本I型和II型。I型转录本在Wx-1基因第五外显子的5’端缺失了6个碱基,编码的GBSSI蛋白缺少两个氨基酸,与淀粉的结合能力降低。II型转录本的第四内含子未被剪接而保留,导致Wx-1基因编码框发生移码提前终止。Wx-1突变降低了GBSSI酶活性,从而导致直链淀粉含量降低。本研究揭示了一种新的Wx-1基因失活机制。

关键词：大麦 EMS Wx-1 RNA异常剪接淀粉结合能力淀粉特性

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Universal linear intensity transformations using spatially incoherent diffractive processors

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Light(Science & Applications) 2023年第9期12卷 1830-1856页

作者： md Sadman Sakib rahman Xilin Yang Jingxi Li Bijie Bai Aydogan Ozcan Electrical and Computer Engineering Department University of CaliforniaLos AngelesCA 90095USA Bioengineering Department University of CaliforniaLos AngelesCA 90095USA California NanoSystems Institute(CNSI) University of CaliforniaLos AngelesCA 90095USA

Under spatially coherent light,a diffractive optical network composed of structured surfaces can be designed to perform any arbitrary complex-valued linear transformation between its input and output fields-of-view(FOVs)if the total number(N)of optimizable phase-only diffractive features is≥~2N_(i)N_(o),where Ni and No refer to the number of useful pixels at the input and the output FOVs,*** we report the design of a spatially incoherent diffractive optical processor that can approximate any arbitrary linear transformation in time-averaged intensity between its input and output *** spatially incoherent monochromatic light,the spatially varying intensity point spread function(H)of a diffractive network,corresponding to a given,arbitrarily-selected linear intensity transformation,can be written as H(m,n;m′,n′)=|h(m,n;m′,n′)|^(2),where h is the spatially coherent point spread function of the same diffractive network,and(m,n)and(m′,n′)define the coordinates of the output and input FOVs,*** numerical simulations and deep learning,supervised through examples of input-output profiles,we demonstrate that a spatially incoherent diffractive network can be trained to all-optically perform any arbitrary linear intensity transformation between its input and output if N≥~2N_(i)N_(o).We also report the design of spatially incoherent diffractive networks for linear processing of intensity information at multiple illumination wavelengths,operating ***,we numerically demonstrate a diffractive network design that performs all-optical classification of handwritten digits under spatially incoherent illumination,achieving a test accuracy of>95%.Spatially incoherent diffractive networks will be broadly useful for designing all-optical visual processors that can work under natural light.

关键词： spatially intensity arbitrary

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Performance Improvement of CIGS Solar Cell: A Simulation Approach by SCAPS-1D

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Energy and Power Engineering 2023年第8期15卷 291-306页

作者： md. Ferdous Wahid md. Nuralam Howlader Nazmul Ahasan md. Mizanur rahman Department of Electrical and Electronic Engineering Hajee Mohammad Danesh Science and Technology University Dinajpur Bangladesh

Thin-film solar cells possess the distinct advantage of being cost-effective and relatively simple to manufacture. Nevertheless, it is of utmost importance to enhance their overall performance. In this research work, copper indium gallium selenide (CIGS)-based ultra-thin solar cell (SC) configuration (Ag/ZnO/ZnSe/CIGS/Si/Ni) has been designed and examined using SCAPS-1D. The numerical calculations revealed that this new design resulted in a substantial improvement in SC performance. This study explores the utilization of two absorber layers, CIGS and Si, both with a total of 2 μm thickness, to enhance device performance while reducing material costs, observing an increase in key SC parameters as the Si absorber layer thickness is increased, reaching a maximum efficiency of 29.13% when CIGS and Si thicknesses are set at 0.4 μm and 1.6 μm, respectively with doping absorber doping density of 1014 cm-3. Furthermore, we analyze the impact of variation in absorber and buffer layer thickness, as well as doping concentration, surface recombination velocity (SRV), electron affinity, series-shunt resistance, and temperature, on optimized CIGS SC parameters such as short-circuit current density (JSC), open circuit voltage (VOC), fill factor (FF), and power conversion efficiency (PCE). The findings yielded by the investigation offer significant elucidation regarding the fabrication of economically viable and highly efficient non-hazardous CIGS ultra-thin SC.

关键词： Thin-Flim CIGS-Based Solar Cell Non-Toxic Solar Cell SCAPS-1D Numerical Simulation Renewable Energy

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Postoperative Acute Bilateral Irvine-Gass Syndrome following Uncomplicated Phacoemulsification Surgery with Trifocal IOL—Two Case Reports

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Open Journal of Ophthalmology 2022年第1期12卷 34-43页

作者： Ishtiaque Anwar Sharah rahman Sofia Akhter Shah Noor Hassan md. Sanwar Hossain Siddiqur rahman Anisur rahman Glaucoma and Cataract Department Bangladesh Eye Hospital and Institute Dhaka Bangladesh Cornea and Cataract Department Bangladesh Eye Hospital and Institute Dhaka Bangladesh Clinical and Research Coordinator Dhaka Eye Care Hospital Dhaka Bangladesh Vitreo-Retina Department Bangladesh Eye Hospital and Institute Dhaka Bangladesh Ophthalmology Department Dr. Sirajul Islam Medical College Dhaka Bangladesh Northern International Medical College Dhaka Bangladesh Dhaka Medical College and Hospital Dhaka Bangladesh

The case studies are about atypical bilateral, postoperative Cystoid Macular Edema (CME) in two patients who underwent bilateral uncomplicated pha- coemulsification surgery with a trifocal Intraocular Lens (IOL). In postoperative follow-up, both the cases presented with complaints of bilateral blurring of vision. Irvine-Gass syndrome has been diagnosed after evaluation of the retina by fundoscopy and OCT macula. Posterior subtenon steroid injection has been prescribed and given. Regular OCT examinations indicated substantial ede- ma improvement. Subsequent improvement in visual acuity was also noted in both cases. Cystoid macular edema can happen in any case irrespective of the quality of IOL. The visual outcome is satisfactorily responsive towards steroid medication.

关键词： Irvine-Gass Syndrome Cystoid Macular Edema (CME) NSAID Postoperative CME

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A Photonic Crystal Fiber Based Asymmetric Slotted Structured Highly Sensitive Refractive Index Plasmonic Biosensor

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Journal of Sensor Technology 2022年第1期12卷 1-17页

作者： md. Arafat rahman Tanvir Ahmed md. Ismail Haque md. Shamim Anower Department of Electrical and Electronic Engineering Rajshahi University of Engineering and Technology Rajshahi Bangladesh Department of Electrical and Electronic Engineering International Islamic University Chittagong Chittagong Bangladesh

Surface plasmon resonance (SPR) sensors have grown in popularity owing to their sensitivity, precision, and capacity for a variety of applications, including detection, monitoring, and sensing, among others. Sensitivity and resolution are two areas where this technology has room for development. A plasmonic biosensor based on an asymmetric slotted PCF structure with extremely high sensitivity has been described and theoretically investigated. This high performance sensor is constructed and completely characterized using finite element method in COMSOL Multiphysics software environment. Sensitivity and resolution are analyzed as performance parameters for the proposed sensor. Numerical simulation exhibits the maximum wavelength-sensitivity of 1100 nm/RIU with 9.09 × 10-6 RIU resolution in the broad measurement range of refractive index from 1.30 to 1.44. A polarization controller can be used to fine-tune this extremely sensitive and wide-ranging refractive index sensor to fulfil a variety of practical needs. This is performed with the consideration of the variation in the refractive index (RI) of the analyte channels. In comparison with earlier PCF-based sensors, the fiber design structure is basic, symmetrical, simple to produce, and cost-effective. Because of the asymmetric air holes and higher sensitivities of the refractive index detector, it is possible to identify biomolecules, biochemicals and other analytes.

关键词： Surface Plasmon Resonance (SPR) Sensor High Sensitivity Photonic Crystal Fiber (PCF) Optical Fiber Sensor

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基于3DSEU-Net不确定性循环焦点平均教师的半监督脑肿瘤分割

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中国医学物理学杂志 2023年第9期40卷 1121-1126页

作者：段逸凡肖洪兵 rahman md Mostafizur 北京工商大学人工智能学院北京100048

准确、完整地定位和分割脑肿瘤对脑胶质瘤患者的存活率以及治疗方案的确定起着决定性作用。在三维核磁共振影像(MRI)中,生成准确的注释需要大量的专业知识和时间成本,使用少量有标签数据与大量无标签数据进行半监督学习更加符合实际的... 详细信息

准确、完整地定位和分割脑肿瘤对脑胶质瘤患者的存活率以及治疗方案的确定起着决定性作用。在三维核磁共振影像(MRI)中,生成准确的注释需要大量的专业知识和时间成本,使用少量有标签数据与大量无标签数据进行半监督学习更加符合实际的临床场景与需求。为此,本文提出一种3DSEU-Net作为半监督模型中的教师与学生网络,该网络引入注意力计算,同时结合跳跃连接,以便获取三维医学影像中更加丰富鲁棒的结构与细节特征,训练过程中,教师模型通过不确定性量化,然后指导学生模型,使学生模型学习到置信度更高的结果,在仅有少量有标签数据的情况下学习到更多的知识,以提升模型的脑肿瘤分割精度。在仅有25个有标签数据的情况下,分割精度比全监督学习提升了12.9%,最高分割精度达81.41%,优于目前可同基准复现的6种半监督方法,证明了本文方法的可行性和有效性。

关键词：三维卷积神经网络通道注意力半监督学习脑肿瘤分割循环焦点损失

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Secure Wireless Multicasting through Nakagami-m Fading Channels with Multi-Hop Relaying

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Journal of Computer and Communications 2023年第5期11卷 177-193页

作者： md. Mizanur rahman md. Zahurul Islam Sarkar Mohammad Mahmud Hasan Department of Electrical and Electronic Engineering RUET Rajshahi Bangladesh

The additional diversity gain provided by the relays improves the secrecy capacity of communications system significantly. The multiple hops in the relaying system is an important technique to improve this diversity gain. The development of an analytical mathematical model of ensuring security in multicasting through fading channels incorporating this benefit of multi-hop relaying is still an open problem. Motivated by this issue, this paper considers a secure wireless multicasting scenario employing multi-hop relaying technique over frequency selective Nakagami-m fading channel and develops an analytical mathematical model to ensure the security against multiple eavesdroppers. This mathematical model has been developed based on the closed-form analytical expressions of the probability of non-zero secrecy multicast capacity (PNSMC) and the secure outage probability for multicasting (SOPM) to ensure the security in the presence of multiple eavesdroppers. Moreover, the effects of the fading parameter of multicast channel, the number of hops and eavesdropper are investigated. The results show that the security in multicasting through Nakagami-m fading channel with multi-hop relaying system is more sensitive to the number of hops and eavesdroppers. The fading of multicast channel helps to improve the secrecy multicast capacity and is not the enemy of security in multicasting.

关键词： Frequency Selective Fading Multi-Hop Relaying Probability of Non-Zero Secrecy Multicast Capacity Secure Outage Probability for Multicasting

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