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American Journal of Operations Research 2024年第1期14卷 74-86页

作者： Abdur Rashid md. amirul islam Department of Mathematics Jahangirnagar University Dhaka Bangladesh Department of Mathematics Uttara University Dhaka Bangladesh

In operations research, the transportation problem (TP) is among the earliest and most effective applications of the linear programming problem. Unbalanced transportation problems reflect the reality of supply chain and logistics situations where the available supply of goods may not precisely match the demand at different locations. To deal with an unbalanced transportation problem (UTP), it is essential first to convert it into a balanced transportation problem (BTP) to find an initial basic feasible solution (IBFS) and hence the optimal solution. The present paper is concerned with introducing a new approach to convert an unbalanced transportation problem into a balanced one and as a consequence to obtain optimum total transportation cost. Numerical examples are provided to demonstrate the suggested method.

关键词： Unbalanced Transportation Problem (UTP) Supply Demand Initial Solution Optimal Solution

An Efficient Approach for Transforming Unbalanced Transportation Problems into Balanced Problems in Order to Find Optimal Solutions

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A Comparative Study on Numerical Solutions of Initial Value Problems (IVP) for Ordinary Differential Equations (ODE) with Euler and Runge Kutta Methods

American Journal of Operations Research（美国运筹学期刊） 2024年第1期

作者： Abdur Rashid md. amirul islam

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American Journal of Computational Mathematics 2015年第3期5卷 393-404页

作者： md. amirul islam Department of Mathematics Uttara University Dhaka Bangladesh

This paper mainly presents Euler method and fourth-order Runge Kutta Method (RK4) for solving initial value problems (IVP) for ordinary differential equations (ODE). The two proposed methods are quite efficient and practically well suited for solving these problems. In order to verify the ac-curacy, we compare numerical solutions with the exact solutions. The numerical solutions are in good agreement with the exact solutions. Numerical comparisons between Euler method and Runge Kutta method have been presented. Also we compare the performance and the computational effort of such methods. In order to achieve higher accuracy in the solution, the step size needs to be very small. Finally we investigate and compute the errors of the two proposed methods for different step sizes to examine superiority. Several numerical examples are given to demonstrate the reliability and efficiency.

关键词： Initial Value Problem (IVP) Euler Method Runge Kutta Method Error Analysis

Analysis of the Impact of Optimal Solutions to the Transportation Problems for Variations in Cost Using Two Reliable Approaches

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American Journal of Computational Mathematics 2023年第4期13卷 607-618页

作者： Abdur Rashid md. amirul islam Department of Mathematics Jahangirnagar University Dhaka Bangladesh Department of Mathematics Uttara University Dhaka Bangladesh

In this paper, we have used two reliable approaches (theorems) to find the optimal solutions to transportation problems, using variations in costs. In real-life scenarios, transportation costs can fluctuate due to different factors. Finding optimal solutions to the transportation problem in the context of variations in cost is vital for ensuring cost efficiency, resource allocation, customer satisfaction, competitive advantage, environmental responsibility, risk mitigation, and operational fortitude in practical situations. This paper opens up new directions for the solution of transportation problems by introducing two key theorems. By using these theorems, we can develop an algorithm for identifying the optimal solution attributes and permitting accurate quantification of changes in overall transportation costs through the addition or subtraction of constants to specific rows or columns, as well as multiplication by constants inside the cost matrix. It is anticipated that the two reliable techniques presented in this study will provide theoretical insights and practical solutions to enhance the efficiency and cost-effectiveness of transportation systems. Finally, numerical illustrations are presented to verify the proposed approaches.

关键词： Transportation Problem Initial Basic Feasible Solution Optimal Solution Two Reliable Approaches (theorems) and Numerical Illustrations

An Effective Approach to Determine an Initial Basic Feasible Solution: A TOCM-MEDM Approach

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Open Journal of Optimization 2020年第2期9卷 27-37页

作者： md. Munir Hossain Mollah Mesbahuddin Ahmed md. amirul islam Shirajul islam Ukil Department of Mathematics Bangladesh Military Academy Chattogram Bangladesh Principal Birshreshtha Noor Mohammad Public College Dhaka Bangladesh

Transportation of products from sources to destinations with minimal total cost plays an important role in logistics and supply chain management. In this article, a new and effective algorithm is introduced for finding an initial basic feasible solution of a balanced transportation problem. Number of numerical illustration is introduced and optimality of the result is also checked. Comparison of findings obtained by the new heuristic and the existing heuristics show that the method presented herein gives a better result.

关键词： Initial Basic Feasible Solution Total Opportunity Cost Matrix Pointer Cost Optimum Solution

New Procedure of Finding an Initial Basic Feasible Solution of the Time Minimizing Transportation Problems

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Open Journal of Applied Sciences 2015年第10期5卷 634-640页

作者： Mollah Mesbahuddin Ahmed md. amirul islam Momotaz Katun Sabiha Yesmin md. Sharif Uddin Department of Mathematics Jahangirnagar University Savar Dhaka Bangladesh Department of Mathematics Bangladesh University Dhaka Bangladesh

Minimization of transportation time is a great concern of the transportation problems like the cost minimizing transportation problems. In this writing, a transportation algorithm is developed and applied to obtain an Initial Basic Feasible Solution (IBFS) of transportation problems in minimizing transportation time. The developed method has also been illustrated numerically to test the efficiency of the method where it is observed that the proposed method yields a better result.

关键词： Transportation Problem Initial Basic Feasible Solution Minimizing Transportation Time

Phytochemical Screening and Evaluation of Pharmacological Potential of Baliospermum solanifolium Leaf Extract

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Clinical Complementary Medicine and Pharmacology 2024年第1期4卷 69-75页

作者： Amit Mazumd.r Rabindra Nath Acharyya Milton Kumar Kundu Pritam Kundu md.amirul islam md.Mustafizur Rahman Pharmacy Discipline Khulna UniversityKhulna-9208Bangladesh

Background:Baliospermum solanifolium is a traditional medicinal plant,locally known as“dantigaacha”from Eu-phorbiaceae family,and has been used in different diseases treatments likes helminthiasis,skin diseases,diabetes,snake-bite,and ***:Depending on the traditional uses of *** and the lack of scientific works,we aimed to conduct some pharmacological tests on its ***:Active constituents of *** were assessed by qualitative ***(2,2-diphenyl-1-picrylhydrazyl)was used for free radical scavenging *** change and mortality rate were used as indicators to assess the toxicity of *** antidiabetic potential was evaluated by oral glucose toler-ance test(OGTT)and alpha-glucosidase enzyme inhibitory *** antidiarrheal activity,castor oil-induced mice were *** test was carried out by disk diffusion assay and MIC ***,analgesic activity was done by acetic acid-induced writhing ***:*** contains alkaloids,carbohydrates,glycosides,flavonoids,tannis,phenolics *** toxicity test ensured the safety of the *** DPPH,the extract showed antioxidant activity with an IC50(con-centration needed to scavenge 50%DPPH)value of 61.65μg/*** phenolic,flavonoid and tannin contents were determined as 124 mg GAE/g,440 mg QE/g and 344 mg GAE/g dried extract,*** OGTT,the ex-tract reduced the blood glucose level *** the alpha-glucosidase inhibitory activity,the plant showed a concentration-dependent reduction of the enzyme at IC50 of 8.53 mg/*** the antidiarrheal test,*** inhibit defecation 30.69%and 53.41%at dose 250 mg/kg and 500 mg/kg,*** extract also showed antibacterial activity against four bacterial strains in the disk diffusion method and minimum inhibitory concen-tration(MIC)values were 62.5μg/mL,62.5μg/mL,125μg/mL and 62.5μg/mL against four bacterial strains,*** an

关键词： Baliospermum solanifolium Antioxidant Antidiabetic Antidiarrheal Antibacterial Analgesic

Unsteady RANS simulation of wind flow around a building shape obstacle

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Building Simulation 2022年第2期15卷 291-312页

作者： Sheikh Hassan md.Mamun Molla Preetom Nag Nasrin Akhter amirul Khan Department of Mathematics&Physics North South UniversityDhaka 1229Bangladesh Department of Mathematics Dhaka University of Engineering&TechnologyGazipur 1708Bangladesh School of Civil Engineering University of LeedsLeeds LS29JTUK

This work aims to find the origin and connection of the surface,near-wake,and far-wake structures in the flow encompassing a high-rise building for a high Reynolds *** origin and interconnection of the stream-wise tip vortices,with the other components of the wake,is analysed in this study for the current *** Unsteady Reynolds Averaged Navier-Stokes equations(URANS)together with the realizable k-εturbulence model have been used in this investigation to study the turbulent wake flow following a ground-surface-attached square shape building.A moderately big obstacle aspect ratio of 4,a Reynolds number of 12,000,and a thin evolving boundary layer thickness have been used in the flow *** designed flow addresses the reversed-flows at the outlet during computation to improve the accuracy of the realizable k-e *** Reynolds stress components are retrieved using the Boussinesq *** wake’s principal compositions,including span-wise-side eddies and area of high stream-wise vorticity in the uppermost portion of the wake,are illustrated by both three-dimensional(3D)representations and planner projections of the mean flow distributions.A braided vortex formation,composed of asymmetric hairpin vortexes,is witnessed in the far-wake *** association of the near-wake vortex structures with the far-wake and near-wall flow,which is associated with the flow strengths,is also *** this investigation,few areas of large stream-wise vorticity magnitude,like tip vortexes,are correlated to the 3D curving of the fluid motion,and tip vortices did not continuously reach to the free end part of the *** 3D fluid motion interpretation,which combined several measurements of the flow distribution encompassing the cylinder,shows that the time-averaged near-wake structures are formed of two segments of distinct source and section of ***,addressing reversed-flow during computation shows notable improvement in the results.

关键词： turbulent wake vortex shedding flow structures tip vortexes model building URANS turbulent boundary layer

Plasmodium cynomolgi: An emerging threat of zoonotic malaria species in Malaysia?

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Asian Pacific Journal of Tropical Medicine 2022年第1期15卷 4-6页

作者： Nor Diyana Dian Mohd amirul Fitri A Rahim Zulkarnain md.Idris Department of Parasitology and Medical Entomology Faculty of MedicineUniversiti Kebangsaan MalaysiaKuala LumpurMalaysia Infectious Disease Group Faculty of MedicineUniversiti Kebangsaan MalaysiaKuala LumpurMalaysia

Malaria remains a public health problem in many parts of the *** is a disease that can endanger human life if left untreated,especially among young children and pregnant *** Malaysia,the number of malaria cases has decreased significantly since the introduction of the Malaria Elimination Program in 1961 in Malaysia Borneo,and in 1967 in Peninsular *** 1988,malaria has been on the notifiable disease list under the Communicable Diseases Act of Malaysia that mandates notification within 7 *** significant progress towards the national elimination programme and effective disease notification on malaria has resulted in zero indigenous human malaria cases in 2018[1].

关键词： malaria Malaria Plasmodium

Effects of Tinospora tuberculata leaf methanol extract on seedling growth of rice and associated weed species in hydroponic culture

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Journal of Integrative Agriculture 2016年第7期15卷 1521-1531页

作者： Farzad Aslani Abdul Shukor Juraimi Muhammad Saiful Ahmad-Hamd.ni Farahnaz Sadat Golestan Hashemi md.amirul Alam md.Abdul Hakim md.Kamal Uddin Department of Crop Science Faculty of Agriculture Universiti Putra Malaysia (UPM) Institute of Tropical Agriculture Universiti Putra Malaysia (UPM) School of Agriculture Science and Biotechnology Faculty of Bioresources and Food Industry Universiti Sultan Zainal Abidin Department of Land Management Faculty of Agriculture Universiti Putra Malaysia (UPM)

The study was conducted to evaluate the responses of rice and rice weed seedlings （barnyardgrass and weedy rice） at the three-leaf stage toTinospora tuberculata leaf methanol extract （3.12, 6.25 and 12.5 g L–1） under hydroponic culture. It shows that the leaf methanol extract had various degrees effects depending on target plant species and each tested index （biomass, root length, shoot length, transpiration volume, chlorophyla, chlorophylb and carotenoid contents）. The effec-tive concentration of the leaf extract capable of reducing 50% of rice growth was higher than those of target weed species. Moreover, the root length was more tolerant to leaf methanol extract in comparison to the other plant parameters measured. A greater reduction was observed in chlorophyla content compared to chlorophylb and carotenoid. The results revealed that the reduction of transpiration volume closely coincided with the magnitude of growth inhibition of tested plants. Ultra-fast liquid chromatography analysis revealed 11 of 32 peaks in chemical proifle, including benzoic acid, caffeic acid, chlorogenic acid, isoorientin, isovitexin, orientin,p-anisic acid, syringic acid,trans-cinnamic acid,trans-ferulic acid, and vitexin have the same retention time with those peaks of the extract. The amount of compounds was present in the range of between 4817 and 115.5 mg kg–1 dry weight （DW）. The concentration-response bioassay of al 11 individual compounds and their equimolar mixture against the seeds of barnyardgrass revealed their contribution in the alelopahic activity ofT. tuberculata leaf extract. The examined compounds and their combination exhibited various degrees of growth inhibitory effects on the early growth of barnyardgrass. Therefore, the speciifc number, concentration, combination and inhibitory activity of bioactive compounds leads to alelopathy activity ofT. tuberculata leaves which could be employable directly as a natural herbicide and its growth inhibitor compounds can be used

关键词： alelochemicals identiifcation and quantiifcation natural herbicide UFLC weed control